RU2289892C2 - Systems and methods for thermal change of ice-to-object interface - Google Patents

Abstract

FIELD: deicing systems and methods.

SUBSTANCE: proposed system has power supply capable of definite-value power generation. Power generated is sufficient for melting ice crust at interface, boundary layer thickness being usually from one micron to one millimeter. Controller can be used for limiting time of definite power generation by power supply to limit unwanted power dissipation into environment. Varying heating energy pulse arriving at interface changes object-to-ice friction.

EFFECT: facilitated deicing procedure.

87 cl, 69 dwg

Description

Related Applications

This application is based on the priority of provisional application for US patent No. 60/356476, filed February 11, 2002, on the priority of provisional application for US patent No. 60/398004, filed July 23, 2002, and on the priority of provisional application for US patent No. 60/404872, filed August 21, 2002

Technical field

The present invention relates to systems and methods for changing the interface between ice and an object.

State of the art

Icing creates many problems in various fields of industry. Such a problem exists in the aviation industry when ice forms on the surface of an airplane. Ice on the surface of an airplane, such as a wing, can create dangerous conditions for an airplane in flight. Another example can be given for land transport, when ice forms on the windshield of the car and can create dangerous conditions for the driver of the car. Removing ice from such surfaces minimizes the risk.

Modern ice removal systems include electric heaters that supply energy to resistive elements to generate heat. Other known systems include chemical solutions for the implementation of chemical reactions for the thermal dissolution of ice. Electric heaters supply a certain energy to the resistive element in order to directly and proportionally melt all the ice from the surface in contact with the electric heaters. Chemical solutions can thermally dissolve ice, but do not work for a long time and create undesirable environmental conditions. These systems are inefficient because they seek to melt all the ice.

Ice removal methods include the use of a mechanical scraper. Mechanical scrapers are often used to remove ice adhering to the surface of an object. However, mechanical scrapers are often manual and inconvenient to use. In addition, mechanical scrapers do not always effectively remove ice and can damage the surface to which ice has adhered.

Untimely removal of ice from the surface of an object can, in principle, have disastrous consequences. For example, overload due to ice on an airplane in flight can dangerously reduce the lift of an airplane and disrupt the proper operation of some components of the airplane. Another example involves the buildup of ice on the windshield of a car, if the ice is not removed, visibility for the driver may deteriorate so much that he will not be able to drive.

SUMMARY OF THE INVENTION

The following patents and patent applications provide useful information and are therefore included in the description by reference: US patent No. 6027075; U.S. Patent No. 6,427,946; PCT Application PCT / US / 25124, filed October 26, 1999; PCT Application PCT / US / 28330, filed November 30, 1999; PCT Application PCT / US / 01858, filed January 22, 2002; PCT Application PCT / US00 / 35529, filed December 28, 2000; US Patent Application Serial No. 09/971287, filed October 4, 2001; and US Patent Application No. 09/970555, filed October 4, 2001.

According to one aspect, a pulsed de-icing system heats the ice-surface interface of an object, disrupting the adhesion of ice and / or snow (or just ice) to the surface. To reduce energy consumption, in one embodiment, the pulse defroster uses a very low heat propagation rate in non-metallic solid materials, including ice and snow, and delivers heating energy to the surface for a sufficiently short time so that the heat does not go far from the interface. Accordingly, most of the heat is used to heat and melt only a very thin layer of ice (hereinafter referred to as “boundary ice”). The system contains a power source capable of generating a certain power. In one case, the power is inversely proportional to the amount of energy used to melt the ice at the interface. The pulse de-icing system may also include a controller to limit the time during which the power source generates a certain amount of power. Duration is essentially inversely proportional to the square of the power value. The power supply may also include a switched power supply capable of delivering a surge voltage. The surge voltage may be generated by a storage device, such as a battery or capacitor. Thus, a battery or capacitor can be used to supply power to the heating element, which is thermally connected to the interface. In some cases, a pulsed voltage can be directly applied to the heating element in order to disrupt the adhesion of ice to the surface. According to another aspect, the heating element includes a thin film of a conductive material or a thin film containing a semiconductor material. The semiconductor material does not make it difficult to view through a thin film, which allows it to be used with such an “object” as the windshield of the machine. The power source can modulate the power supplied to the semiconductor material to convert power into thermal energy. Modulated power transfers a certain amount of thermal energy, which can interfere with the adhesion of ice to the surface.

In some aspects, the capacitor is either a supercapacitor or an ultracapacitor. The power source is a flywheel and / or a high voltage power source. Power from the power source can be converted into thermal energy in order to break the adhesion of ice to the surface of the object. For example, a system can use a power source to remove ice and snow from the surface of an airplane, tire, windshield of a car, boat, road, bridge, sidewalk, freezer, refrigerator, building, treadmill, or window. It is clear to those skilled in the art that ice can also be removed from other objects using a pulsed de-icing system.

According to another aspect, the heat transfer system uses a heat storage subsystem connected to the heating element. The heating element may include a heat-conducting material, such as metal. The heating element may include a membrane attached to the heating element. The membrane, for example, can be inflatable, which prevents the transfer of heat to the surface of the object from which it is necessary to remove ice. When the membrane is blown off, the heating element transfers thermal energy to the surface, which disrupts the adhesion of ice to the surface. The membrane can often be inflated and deflated to modulate the transfer of thermal energy to the surface.

According to another aspect, the heating element comprises two sections of heat-conducting material separated by a heat insulator. At least one of the sections of the heat-conducting material is movably connected to the heat insulator, so that when the sections are arranged in a certain way, the two sections are physically in contact with each other. The movement of at least one of the sections can be modulated with a certain frequency, as a result of which one section of the heat-conducting material transfers to the other section an appropriate amount of thermal energy. The transfer of thermal energy disrupts the adhesion of ice to the surface of another area.

According to yet another aspect, a method for thermally changing boundary ice at an interface between an object and ice is provided. The method includes the step of supplying thermal energy to the interface to melt the boundary layer of ice. The feeding stage is time-limited, as a result of which the energy of heating supplied to the interface is dissipated, and the distance of heat dissipation in ice does not exceed the thickness of the boundary layer of ice.

The step of supplying thermal energy comprises the step of supplying power to the interface, the value of which is at least approximately inversely proportional to the amount of energy used to melt the boundary layer of ice. The duration is limited by limiting the duration of the stage of power supply to the interface so that the duration is at least approximately inversely proportional to the square of the power value.

In another case, the step of supplying heating energy includes the step of supplying power to the interface, the magnitude of which is substantially inversely proportional to the amount of energy used to melt the boundary ice. The duration is limited by limiting the duration so that the duration is essentially inversely proportional to the square of the power value.

The method includes an additional step of facilitating re-freezing of the boundary layer of ice to influence the coefficient of friction between the object and the ice. For example, the facilitation step may include one or more of the following steps: (1) waiting for re-freezing after the duration limitation step; (2) blowing the interface with cold air; (3) spraying water at the interface.

According to certain aspects, an object is one of the elements: aircraft structure, windshield, mirror, headlight, power line, funicular design, wind turbine rotor surface, helicopter rotor surface, roof, deck, building structure, road, bridge structure, freezer structure, antenna , satellite dish, railway construction, tunnel construction, cable, road sign, snowshoe, ski, snowboard, skate and boot.

According to another aspect, the step of supplying heating energy to the interface includes the step of supplying thermal energy to the interface to melt the boundary layer of ice less than five centimeters thick. In some cases, the method step limits the duration, as a result of which the boundary layer of ice has a thickness of less than one millimeter. In another embodiment, the heat dissipation distance is further limited by limiting the pulse duration, whereby the thickness of the boundary layer is from one micron to one millimeter.

At the stage of limiting the duration, thermal energy is supplied to the interface for a maximum of 100 s. According to another variant, at the stage of limiting the duration, the duration of the supplied thermal energy is limited to 1 ms to 10 s.

According to another aspect, the step of supplying thermal energy to the interface includes the step of supplying power to a heating element thermally coupled to the interface located in the object and / or in contact with the interface. The step of supplying thermal energy may comprise the step of creating electrical resistance for the power using the heating element.

The feeding steps and restrictions are periodically repeated to create the desired coefficient of friction between the object and the ice.

Power is reapplied to the interface after re-freezing the boundary layer to selectively adjust the coefficient of friction between the ice and the object when the object moves on ice.

Specialists in this field know that in certain cases the ice may contain or be replaced by snow without deviating from the scope of the invention.

In one aspect, the object is a moving body, such as a boot, snowboard, or ski.

According to the invention, a method for controlling the coefficient of friction between an object and ice is provided, comprising the following steps:

(1) applying pulsed power to the interface between the object and the ice, to melt the boundary layer of ice at the interface and reduce the coefficient of friction,

(2) facilitate re-freezing of boundary ice at the interface to increase the coefficient of friction,

(3) repeat the control of steps (1) and (2), while controlling the average coefficient of friction between the object and the ice.

The step of facilitating re-freezing includes the step of moving the object on ice to lower the temperature of the object. For example, a car tire can be heated and then rotated (while the machine is moving) to bring a heated tire into contact with an icy road, to facilitate re-freezing.

The step of applying pulsed power includes the steps of blowing an object (for example, a car tire) with first air, which has a temperature above the freezing point and moving the object in contact with ice. The step of facilitating re-freezing includes the step of blowing the object (for example, a tire) with second air, the temperature of which is lower than the temperature of the first air.

It is envisaged that the surface of the moving body should be in contact with ice or snow. A power source (such as a battery) generates power. The heating element is capable of converting power to heat on the surface, and there is enough heat to melt the boundary layer of ice at the interface. The controller controls the power supply to the heating element to adjust the coefficient of friction between the sliding body and ice or snow.

A sliding body may be, for example, a boot, snowboard, ski or snowshoe.

According to one aspect, the sliding body is a ski, skate or snowboard, and the controller responds to user commands by modulating the power supplied to the surface, which allows you to control the speed of the sliding body. Thus, the skier can, if desired, adjust his speed when skiing.

In yet another aspect, a windshield de-icer is provided. The windshield de-icer contains a windshield and an almost transparent heating element located on the windshield, which generates heat when power is supplied in an amount sufficient to melt the boundary layer of ice on the windshield.

The heating element is selected from a visually transparent semiconductor material in which the band gap for electrons exceeds about 3 eV. As such a material, ZnO, ZnS or mixtures thereof can be used.

According to another embodiment, the heating element is selected from a transparent conductive material. For example, indium tin oxide (ITO), tin oxide, thin metal films or mixtures thereof can be used as the conductive material.

Brief Description of the Drawings

The invention is further explained in the description of the preferred embodiments with reference to the accompanying drawings, in which:

figure 1 depicts a diagram of a pulse de-icing system for changing the interface between the object and ice according to the invention;

figure 2 - diagram of a pulse de-icing system according to the invention;

figure 3 - diagram of a pulse de-icing system according to the invention;

4 is a diagram of a pulse anti-icing system according to the invention;

5 is a diagram of a pulse anti-icing system according to the invention;

6 is a diagram of a pulse de-icing system for an aircraft wing according to the invention;

7 is a diagram of a multi-layer heating element of a pulsed defroster according to the invention;

Fig. 8 is a diagram of a heating element of a pulse deicer according to the invention;

FIG. 9 and 10 show the heat dissipation distance for a certain time for a pulse de-icing device according to the invention;

11 is a diagram of the dependence of the time of defrosting on the energy of removal of ice for a pulse de-icing system according to the invention;

12 is a diagram of an RF anti-icing system for changing the interface between ice and an object according to the invention;

13 is a diagram of an RF anti-icing system according to the invention;

FIG. 14 is a diagram for analyzing an RF anti-icing system according to the invention; FIG.

Fig - many types of one comb electronic circuits used in the RF anti-icing system according to the invention;

Fig is a General view and a top view of a comb electronic circuit used in the RF anti-icing system according to the invention;

Fig is a diagram of the frequency dependence of the electrical conductivity of the ice and the dielectric constant of ice according to the invention;

Fig. 18 is an electrical diagram of an RF anti-icer according to the invention;

Figs. 19-29 are diagrams of the results of certain tests of the circuit shown in Fig. 18 according to the invention;

30-35 are diagrams of a convection heat transfer mechanism in an RF anti-icing system and heat transfer through a substrate of an RF anti-icing system according to the invention;

Fig. 36 is a diagram of a heat transfer anti-icing system for changing an object and ice interface according to the invention;

Fig. 37 is a diagram of a heat transfer anti-icing system according to the invention;

Fig. 38 is a diagram of a heat transfer anti-icing system according to the invention;

Fig. 39 is a diagram of a pulsed de-icing system allowing it to be compared with a de-icing system with heat transfer according to the invention;

40 is a diagram of a heat transfer anti-icing system according to the invention;

Fig. 41 is a diagram of a heat transfer anti-icing system according to the invention;

Figures 42-46 are diagrams for analyzing a heat transfer anti-icing system according to the invention;

FIG. 47 and 48 are characteristics of a sliding body according to the invention;

49 is a diagram of a sliding device illustrating a friction change test at an object-ice interface according to the invention;

FIG. 50 and 51 show a sliding body in the form of a ski according to the invention;

Fig - sliding body in the form of a snowboard according to the invention;

Fig - sliding body in the form of a boot according to the invention;

Fig. 54 is a tire-like sliding body according to the invention;

55 is a diagram of a test configuration of a sliding body according to the invention;

56 is a caterpillar-like sliding body according to the invention;

Fig - sliding body in the form of a ski according to the invention;

Fig. 58 is a tire-like sliding body according to the invention;

59 is a diagram of a test configuration of a sliding body according to the invention;

60 is a diagram of the relationship between the friction coefficients of the sliding bodies and the voltage supplied to the heating elements connected to the sliding bodies according to the invention;

Fig. 61 is a diagram of the relationship between resting friction force and normal pressure exerted by sliding bodies on snow according to the invention;

Fig.62 is a diagram of the relationship between the friction coefficients of the sliding bodies and the voltage supplied to the attached heating element according to the invention;

Fig. 63 is a diagram of the relationship between the friction coefficients of one sliding body and the time required to stop the sliding body according to the invention;

Fig. 64 is a diagram of another relationship between the friction coefficients of one sliding body and the voltage supplied to the connected heating element according to the invention;

FIG. 65 and 66 are diagrams of thermal energy and cooling time of a sliding body according to the invention;

Fig. 67 is a diagram for analyzing an increase in friction for a sliding body according to an embodiment, where the tire according to the invention acts as the sliding body;

FIG. 68 and 69 are friction diagrams between a sliding body and snow according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The following specific embodiments of the invention relate to systems and methods for changing the interface between an object and ice. According to one embodiment, the system delivers energy to the interface between the ice (or snow) and the surface of the object to remove ice from the surface in order to “freeze” the object. According to another embodiment, the system modulates the melting in the boundary layer of ice at the ice-object interface, as a result of which the melted boundary layer is quickly re-frozen, which allows you to change the coefficient of friction between the surface of the object and the ice.

Certain embodiments of anti-icers or sliding bodies involve the use of high-frequency (HF) alternating current (AC) power sources, other embodiments of anti-icers or sliding bodies involve the use of direct current (DC) power supplies and / or heat transfer systems (e.g., heat storage systems) )

The following sections are entitled: “Pulse de-icing systems”, “Heating elements used in pulsed de-icing systems”, “Analysis of pulsed de-icing systems”, “HF de-icing systems”, “Comb electronic circuit for use in a pulsed de-icing system”, “HF analysis de-icing systems "," De-icing systems with heat transfer "," Analysis of de-icing systems with heat transfer "," Methods of adjusting the friction coefficient "and" Anal from adjusting the coefficient of friction. "

Some sections describing pulsed de-icing systems describe operations for removing ice by melting a boundary layer of ice that has adhered to the surface of an object. The heating elements of some pulsed de-icing systems can also be used to melt the boundary layer, for example, by electrically connecting a direct or alternating current power source. Other embodiments of pulsed de-icing systems include modulation of heating at the interface between the ice and the object, due to which the object is repeatedly frozen (during the period of no heating) and the friction coefficient between the object and ice changes. Some pulsed deicers act as, or in conjunction with, a sliding body, as described below.

In some sections, operations are described to remove ice by melting the boundary layer of ice adhering to the surface of an object. The comb electrodes of some RF anti-icing systems can be used to melt the boundary layer and can be powered, for example, from an AC power source.

Other embodiments of RF anti-icing systems can be used to change the coefficient of friction between ice and a sliding body. By a moving body is meant an object that can come in contact with ice and / or snow. It can slip due to the interaction with ice and / or snow and the coefficient of friction between the sliding body and ice and / or snow. Examples of sliding bodies include tires, skis, snowboards, boots, snowmobile tracks, sleigh runners, airplane landing gears, etc.

Some sections describe anti-icing systems with heat transfer to remove ice by melting the boundary layer of ice adhering to the surface of the object. Heat transfer de-icing systems may contain heat storage subsystems in which thermal energy is stored. The thermal energy accumulated in the heat storage subsystems can be transferred to a heating element thermally connected with the interface between the object and ice. Some embodiments of heat transfer anti-icing systems include the accumulation of thermal energy and the selective or controlled transfer of this energy to the interface between the object and the ice.

In other embodiments of the invention below, systems are described that change the coefficient of friction between ice and a sliding body by melting a boundary layer of ice adjacent to the sliding body. After melting, the boundary layer is re-frozen to create a bond between the sliding body and ice. This connection acts as a “brake”, which increases the coefficient of friction between the sliding body and the ice. Then re-melt the boundary layer to break the bond, again changing the coefficient of friction. This modulated interaction of freezing and re-freezing at the interface between the object and ice allows you to adjust the friction coefficient to the desired value. Adjustable coefficient of friction is useful in devices such as racing skis, snowshoes, boots, snowboards, skates and other devices that interact with ice and snow.

Pulse de-icing systems

Pulse de-icing systems can be used to remove ice from the surface of an object. Systems can also be used to melt the boundary layer of ice and / or change the coefficient of friction at the interface between the object and ice, which is described in more detail below.

Figure 1 shows a pulse de-icing system 10 for changing the interface 15 between the object 16 and the ice 11. The system 10 contains a power source 12, a controller 14 and a heating element 13. The power source 12 is capable of generating power, the magnitude of which is inversely proportional to the amount of energy used to melt boundary ice (hereinafter referred to as “boundary ice”) at the 15th interface. The heating element 13 is connected to a power source 12 to convert power to heat at the interface 15. The controller 14 is connected to a power source 12 to limit the time during which the heating element 13 converts power to heat. The time during which the heating element 13 converts the power into heat at the interface 15 is essentially inversely proportional to the square of the power value.

In particular, when the heating power density W (W / m ² ) arrives during the time t at the interface between the ice and the substrate, the heat spreads to the distance l _rl in ice and to the distance l _rn in the substrate. The thickness of these heated layers and their respective heat capacities determine how much heat is absorbed. If the thermal conductivity coefficients of ice and the substrate are λ _l and λ _p, respectively, ρ _l and ρ _p are the corresponding densities and C _l and C _p are the corresponding specific heat, then, as is known to a person skilled in the art, the heat flux Q _l in ice and the heat flux Q _p in the substrate can be expressed as follows:

Q _l ≈ C _l l _rl ρ _l (T _t -T), (0-1)

where T _t -T is the temperature difference at the interface,

Q _p ≈ C _p l _rp ρ _p (T _t -T) (0-2)

(0-3)

(0-3)

(0-4)

(0-4)

Solving Lv. (0-1) - Lv. (0-4) relative to the total amount of heat removed from the interface, you can find:

(0-5)

(0-5)

where W is the density of the heating power at the interface.

The above algebraic analysis gives an approximate result of the energy consumption provided by the pulse anti-icing system. An accurate mathematical calculation by solving partial differential equations makes it possible to predict, for ice removal time t and ice removal energy Q, the following illustrative embodiment.

For example, the controller 14 can adjust the time of power supply to the heating element 13 according to the following ratio:

(1-1)

(1-1)

where T _t is the melting temperature of ice; T is the ambient temperature; λ is the coefficient of thermal conductivity; ρ is the density of the material; C is the specific heat of the material (the subscript “l” denotes ice and / or snow, and the subscript “p” denotes the substrate material); W - power per square meter.

In this example, the controller 14 also adjusts the amount of power supplied to the heating element 13 so that the energy Q at the interface 15 is substantially inversely proportional to the amount of power. In this example, the controller 14 adjusts the amount of power according to the following relationship:

(1-2)

(1-2)

Accordingly, in order to achieve the desired temperature (for example, to melt ice at the interface 15), having spent less energy, it is necessary to increase the heating power W by supplying the heating power for a shorter period of time. For comparison, the result of a simplified analysis of ur. 0-5 differs from more accurate solution ur. 1-2 by the coefficient π / 4 = 0.785. These equations, in particular, are useful for describing short power pulses when the heat dissipation length is less than the thickness of the target object (for example, the thickness of the boundary ice at the interface 15).

A more accurate approximation can be obtained by adding the energy used to melt a very thin layer of boundary ice and to heat a thin heater with a thickness d _dag , Q _min :

Q _min = l _l ^. q ^_l. ρ _l + d _Nag ^. C ^_naked. ρ ^_naked. (T _t -T), (1-3)

where l _l is the thickness of the melted layer; ρ _l is the density of ice; q _l - latent heat of melting ice; C _nag and ρ _nag - specific heat and density of the heater. In this example, the controller 14 may adjust the amount of power according to the following relationship:

Energy received by Ur. 1-4, is calculated per square meter (J / m ² ). In ur 1-4, you can also add a term associated with the convective mechanism of heat conduction, but this term is usually neglected due to the very short duration of the heating pulse. When the thickness of the substrate and / or ice layer is less than the heat dissipation lengths (lvl 0-3, lvl 0-4, respectively), the energy is even less than that obtained from lvl. 1-4.

System 10 can, for example, be used in a car to remove ice 11 from the windshield (as object 16). In this example, the heating element 13 is transparent and integrated into the windshield 16, and the power supply 12 and the controller 14 work together to supply enough power to melt the boundary ice at the interface 15 in accordance with ur. 1-1 and 1-2.

To further illustrate the operation of system 10, consider the properties of ice:

λ _l = 2.2 W / m ^. K, ρ _l = 920 kg / m ³ , c _l = 2 kJ / kg ^. K, q _l = 333.5 kJ / kg. (1-5)

The properties of a conventional windshield (for example, as a substrate) are as follows:

λ _p ≈ 1 W / m ^. K, ρ _n ≈ 3,000 kg / m ^3, c _n ≈ 1.54 kJ / ^kg. K. (1-6)

According to ur 1-1, the time required to reach the ice melting temperature (0 ° C) at an initial temperature of -10 ° C and at an energy flux density of 100 kW / m ² is t ≈ 0.142 seconds for a substrate 16 of glass or glass-like material. Correction based on ur. 1-3 can add to the duration of about 0.016 seconds, i.e. about 10%. With a decrease in the peak heating power by a factor of ten (for example, from 100 kW / m ² to 10 kW / m ² ), this time increases by about two orders of magnitude. For comparison, at -30 ° C the total time for removing ice at W = 100 kW / m ² can be 1.42 seconds. The corresponding total energy Q of ice removal at W = 100 kW / m ² and -10 ° C can be expressed as

(Ур. 1-7)Q = 100 kW / m ^2. 0.158 s = 15.8 kJ / m ² .

(Lv. 1-7)

At the same temperature and lower power W = 10 kW / m ^{2, the} energy Q, expressed by Ur. 1-4 will be

(Ур. 1-8)Q = 144 kJ / m ² .

(Lv. 1-8)

This result is almost an order of magnitude larger than at W = 100 kW / m ² .

An advantage of the above example is the use of reduced ice removal energy compared to known systems, by about one order of magnitude by increasing the energy flux density by about an order of magnitude while reducing the power supply time by about two orders of magnitude. By limiting the time of power supply to the interface 15, the flow of thermal energy into the environment and into the ice mass 11 is limited. On the contrary, due to shorter power pulses, more energy remains within the interface 15 to melt the boundary ice.

Figure 2 shows a pulsed de-icing system 20 according to another embodiment of the invention. The de-icing system 20 includes a direct current power supply 22, a capacitor 26, a resistive heating element 28 and a switch 24. A direct current power supply 22 is capable of supplying power to charge the capacitor when the switch 24 is closed to terminal 23. The capacitor 26, being connected to the resistive heating element 28 through contact 25, is capable of delivering a certain power in accordance with the equations of FIG. 1. The switch 24 is, for example, under the operational control of a controller or microprocessor to issue a current pulse from the capacitor 26 to the resistive heating element 28, when the switch 24 is closed to terminal 25 (Eq. 1-1 of FIG. 1). DC power supply 22 charges capacitor 26 when switch 24 is closed to terminal 23. After charging capacitor 26, switch 24 opens and then closes to terminal 25 to discharge current to resistive heating element 28. Resistive heating element 28 generates sufficient heating power to melt boundary layer of ice at the boundary of the object, for example at the border 15 (figure 1). Depending on the application of the pulsed de-icing system 20, boundary layer heating is useful for removing ice from the surface of an object, preventing its formation on the surface and / or changing its adhesion strength and / or changing the coefficient of friction between ice or snow and the object.

FIG. 3 shows a pulsed de-icing system 30 according to another embodiment. The pulse de-icing system 30 comprises a pair of power lines 32, a heating element 34, a capacitor 38, a switch 36, and a power source 37. Pulse de-icing system 30 is capable of removing ice adjacent to element 34 (for example, element 34 is located at, in and / or at the site from which ice is to be removed). In the embodiment shown in FIG. 3, the capacitor 38 is a supercapacitor having a capacitance of about 1000 F. and a potential of about 2.5 V, for example, a Maxwell Technology PC2500 supercapacitor. In addition, the heating element 34 includes a 50 μm thick stainless steel foil sheet attached to a 1 cm thick Plexiglas plate, and the power supply 37 is a DC power supply with a 2.5 V EMF. Switch 36 may act as a high current mechanical switch to limit the time during which the power supply 37 supplies power to the heating element 34. In some cases, the switch 36 acts as an electrical switch receiving a control signal from the counter Weller, such as controller 14 (Figure 1). The resistance of the heating element 34 is about 6 mΩ. With an initial power density of about 40 kW / m ² , a total stored energy of about 3.125 kJ and a total energy density of about 83.33 kJ / m ^{2, the} pulsed de-icing system 30 effectively removes about 2 cm of ice on a surface area of about 375 cm ^{2 in} about one second at an ambient temperature of about -10 ° C using an energy density of about 40 kJ / m ² .

According to another embodiment of the pulse de-icing system 30, the capacitor 38 is a car battery, for example, EverStart®; a car battery with a peak current of about 1000 A and a potential of about 12 V. In addition, according to this embodiment, the heating element 34 comprises a 100 μm thick stainless steel foil sheet attached to a 1 cm thick Plexiglas plate. The switch 36 may be, for example relay. With an initial power density of about 25 kW / m ^{2, the} pulse de-icing system 30 effectively removes about 2 cm of ice on a surface area of about 375 cm ^{2 in} about two seconds at an ambient temperature of about -10 ° C using an energy density of about 50 kJ / m ² . According to another embodiment, the power supply 37 is a 2.5 V DC power supply that charges the capacitor 38.

4 shows one pulsed de-icing system 40 in accordance with yet another embodiment of the invention. The de-icing system 40 includes a direct current power supply 42, a capacitor 45, a resistance heating element 46, a direct current converter 44 and a switch 48. A direct current power source 42 is capable of supplying power through the direct current converter 44 to charge the capacitor 45 when the switch 48 is closed to terminal 41. The DC / DC converter 44 is capable of increasing the voltage provided by the DC power source 42. The capacitor 45 is connected to the resistive heating element 46 through contact 43 and is capable of delivering some power in accordance with the equations of FIG. 1. The switch 48 is, for example, under the operational control of a controller or microprocessor to provide a current pulse from the capacitor 45 to the resistive heating element 46 when the switch 48 is closed to contact 43 (Eq. 1-1 of FIG. 1). DC power supply 42 charges capacitor 45 when switch 48 is closed to terminal 43. After charging capacitor 45, switch 48 opens and then closes to terminal 43 to discharge current to resistive heating element 46. Resistive heating element 46 generates sufficient heating power to melt boundary layer of ice. Depending on the application of the pulse anti-icing system 40, melting of the boundary layer is useful for removing ice from the surface of the object, preventing its formation on the surface and / or changing the strength of its adhesion and / or changing the coefficient of friction between the ice and the object. Pulse de-icing system 40 is also useful when large power supplies are unavailable or when objects have a small area of contact with snow, for example, for a boot (for example, boot 684, FIG. 61). According to one embodiment, the pulse de-icing system 40 is used as a “pulse brake”, described in detail below.

5 shows a pulse de-icing system 50 according to another embodiment of the invention. Pulse de-icing system 50 is able to remove ice from the object and contains de-icer 62, a pair of power bus 64, a thermocouple 63, a thermocouple block 52, an amplifier 54, a battery 58, a relay 59, a capacitor 61, a semiconductor relay (PPR) 60 and a computer system 57. The de-icer 62 is connected to power buses 64 for receiving power from battery 58. Computer system 57 is connected to de-icer 62 through thermocouple unit 52 and an amplifier 54 for receiving temperature information about de-icer 62 through thermocouple 63. Computer system 57 may include a board 55 of an analog-to-digital converter (ADC), capable of receiving temperature information in analog form and converting analog temperature information to digital format for use by computer system 57, which is connected to defroster 62 through PPR 60 to control the duration and amount of power supplied to the defroster 62, for example, in accordance with the equations of FIG. The computer system 57 operatively controls the PPR 60 and the relay 59 to supply power from the battery 58 to the defroster 62.

The SPR 60 can be replaced by an electromagnet 67 and a switch 66. The computer system 57 may further include a transistor-transistor logic (TTL) unit 56 for supplying control information to the SPR 60, so that when the electromagnet 68 receives a step input signal from the TTL module 56, The electromagnet 68 closes the switch 65. When the switch 65 is closed, the capacitor 61 is discharged into the electromagnet 67 to close the switch 66. When the switch 66 is closed, the battery 58 supplies power to the defroster 62. The computer system 57 is turned off it receives power from the defroster 62 when the temperature rises to a certain level, which is determined by thermocouple 63. Computer system 57 receives temperature information from thermocouple 63 through thermocouple unit 52 and amplifier 54. Thermocouple unit 52 transmits temperature information to computer system 57. Amplifier 54 amplifies the temperature information, after which the 55 A / D converter board digitizes the temperature information for the computer system 57. When the temperature of the defroster 62 reaches a certain level, then In order to melt the boundary layer of ice, the computer system 57 instructs the TTL unit 56 to open the switch 65 by means of the electromagnet 68. Since the switch 65 opens when the computer system determines that the power supply should be disconnected from the defroster 62, the capacitor 61 discharges and the switch 66 opens because Solenoid 67 no longer receives voltage. When this electromagnet 67 begins to charge the capacitor 61.

The defroster 62 is made of stainless steel with a thickness of 50 μm and attached to the front edge of the small aerodynamic surface (for example, the front open portion of the wing of the aircraft). According to this embodiment, the aerodynamic surface has a span of about 20 cm and a thickness of about 5 cm, and defroster 62 has dimensions of about 20 cm x 10 cm.

System 50 was tested as follows. Defroster 62 was formed on the aerodynamic surface and placed in an icy wind tunnel, it was tested at an air speed of about 142 km / h at -10 ° C with water droplets about 20 microns in size. Atmospheric ice formed on the aerodynamic surface. After the growth of ice with a thickness of 5 mm to 10 mm, the computer system 57 ordered the battery 58 to supply power to the defroster 62 in the form of pulses, as shown in Fig.5. With a power density W of about 100 W / m ² and a pulse duration t of power of about 0.3 seconds, de-icer 62 melts the boundary layer of ice on the aerodynamic surface, as a result of which the adhesion of ice to the aerodynamic surface changes significantly and / or disappears. After that, the ice is removed from the aerodynamic surface by the drag force of the air. The pulse duration in this example is longer than in the example of the windshield, due to the greater heat capacity of the metal foil heater.

FIG. 6 shows a pulse de-icing system 70 for an airplane wing 80 in accordance with one embodiment. The pulse de-icing system 70 comprises a power supply 74 and a controller 78. The power supply 74 is capable of generating power, the magnitude of which is substantially inversely proportional to the amount of energy used to melt the boundary layer of ice at the interface 73. It is shown that the boundary 73 of the section is the surface of the wing 80 of the aircraft in contact with ice and / or snow. Pulse de-icing system 70 also includes a heating element 75 connected to a power source 74 to convert power to heat at the interface 73. System 70 includes a controller 78 connected to a power source 74 to limit the time during which the heating element 75 converts power to heat. The duration of the power supply, for example, is inversely proportional to the square of the power value.

System 70 also includes an ice detector 72 and a temperature sensor 76. A temperature sensor 76 is attached to the interface 73 to record a temperature at the interface 73. The temperature sensor 76 provides temperature information about the interface 73 in the form of a feedback signal to the controller 78. The controller 78 processes the temperature information to control the mode of power supply to the heating element 75 and / or the interface 73.

An ice detector 72 is capable of detecting ice thickness at a interface 73. The ice detector 72 may, for example, include an electrode grid that facilitates the measurement of ice thickness. Since ice has a unique dielectric constant different from the dielectric constants of water and air, the presence and thickness of ice can be determined by measuring the interelectrode capacitance of the ice detector 72. The ice detector 72 transmits ice information (eg, the presence and thickness of ice) to the controller 78. The controller 78 processes the information to determine when to apply power to the heating element 75. According to one embodiment, when the ice on the wing 80 of the aircraft reaches a certain thickness , the controller 78 automatically determines the need for ice removal and promptly instructs the power supply 74 to supply power to the heating element 75.

An example of the operational characteristics of system 70 is described below. Consider an anti-icer environment in which the external temperature T is about -10 ° C, the air speed is about 320 km / h and the wing thickness of the aircraft 80 is about 10 cm, with a convective heat transfer coefficient h _to about 1200 W / ^K. m ² (based on experimental data).

In comparison, the prior art de-icing system supplies power W to the wing surface of an airplane 80 to maintain a temperature T _t on the wing surface of an airplane 80 above the freezing point of water (for example, 0 ° C) according to the following equation:

(Ур. 6-1)W = h _k (T _t -T) = 12 kW / m ² .

(Lv. 6-1)

Maintaining this power for three minutes gives a large amount of energy Q, expressed by the following equation:

(Ур. 6-2)W = 12 ^. 10 ³ W / m ^2. 180 s = 432 kJ / m ² .

(Lv. 6-2)

Pulse de-icing system 70 differs from the known de-icing system in that it melts the boundary layer of ice at the interface, and not all of the ice. Pulse de-icing system 70 cleans the aerodynamic surface of ice using only 30 kJ / m ² . With a three-minute interval between pulses, the pulse anti-icing system 70 consumes a very low “average” power:

W _medium = 30 kJ / 180 s ^. m ² = 0.167 kW / m ² . (Lv. 6-3)

In particular, the result of Ur. 6-3 is only 1.4% of what the electrothermal defroster uses according to Eq. 6-2.

According to this embodiment, the pulse de-icing system 70 provides energy pulses to the heating element 75 according to the equations of FIG. 1. The heating element 75 may include a grid of electrodes for melting the boundary layer of ice at the interface 73 of the section. When the ice thickness reaches a predetermined predetermined value (for example, 3 mm), the controller 78 instructs the power supply 74 to apply a short power pulse to the heating element 75. The pulse duration depends on the temperature supplied by the temperature sensor 76, the power supplied by the power supply 74, and physical the properties of the substrate material (for example, the wing surface 80 of the aircraft and / or the heating element 75). For example, the pulse width of the supplied power can be expressed by Ur. 1-1 of Fig. 1.

In the pulse de-icing system 70, a second sensor (not shown) is used near the heating element 75 to improve power control. For example, when the boundary temperature reaches a certain value when applying pulsed power, the controller 78 may instruct the power supply 74 to disconnect the power from the heating element 75 and, thus, reduce power consumption.

Experiments with various heaters, for example, an RF heater with losses in the dielectric and a direct current heater, give results that correspond to the theoretical predictions described above. In some embodiments discussed herein, when the icing area is too large for the power source to heat the entire area at the same time, de-icing can be carried out site by area. For example, you can remove ice from the entire structure by sequentially removing ice from these areas. The drag force of an aircraft can further remove ice from the aerodynamic surface. However, since it takes time for most of the wing 80 of the aircraft, facing forward, to be supported unfrozen (for example, a dividing strip), the average power expressed in Ur can increase. 6-3. Other heaters can be used in the pulsed de-icer system 70, for example, a heater using hot air taken from a compressor, which is available in many aircraft.

Heating elements used in pulsed de-icing systems

In some of the embodiments described below, heating elements are used in various pulse de-icing systems. These heating elements receive power from a power source, such as a direct current power source, and then melt the boundary layer of ice at the interface. When the boundary layer of ice is melted, the ice is removed or re-frozen depending on the requirements, which is described in more detail below.

FIG. 7 shows a multilayer structure 90 of an anti-icer heating element for removing ice from structure 92, for example, by supplying power in accordance with the equations of FIG. 1. The multilayer structure 90 comprises an electrical and substrate heat insulator 94, an electrically conductive layer 96 and a protective layer 98. The layer 96 receives power and converts it into heat to remove ice from the structure 92 and / or to prevent its formation. Layer 96 is one of the various heating elements described herein. According to one embodiment, the multilayer structure 90 comprises a plurality of individual components attached to the structure 92 to form “cells” in which ice can be individually removed (for example, to remove cell by cell or site by site).

The power supplied to the multilayer structure 90 is from 10 kW / m ² to 100 kW / m ² . Accordingly, to supply such power, you need to select a power source with a capacity of from about 10 kJ / m ² to 100 kJ / m ² depending on the required ice removal time and external temperature. Some power supplies with these characteristics are chemical batteries, supercapacitors, ultracapacitors, electrolytic capacitors, flywheels associated with generators, DC / DC converters and inverters, and combinations thereof.

Modern chemical batteries have a high density of stored electrical energy (for example, 60 kJ / kg for a lead battery). However, chemical batteries have a relatively low power density. For example, a car battery can deliver up to about 1000 A at twelve volts for about ten seconds, which corresponds to a power of about 12 kW. A typical car battery has a large capacity, approximately Q ≈ 12 V × 100 A × 3600 c = 4.32 10 ⁶ J. Therefore, for use in pulsed de-icing systems and methods, a car battery can effectively remove ice from areas up to about 1.5 m ² that is ideal for automotive windshields.

Supercapacitors and ultracapacitors are known as good sources of peak power and peak capacitance. Some supercapacitors can store 10 J / kg and deliver 1.5 kW / kg of power (for example, the Maxwell Technology PC2500 supercapacitor). As a power source, supercapacitors can be very suitable for use with a multilayer structure 90 in pulsed de-icing systems.

A flywheel made of lightweight composite materials and connected to a generator provides another energy storage device. Some flywheels can accumulate up to 2 MJ / kg and, when connected to a generator, can produce a power density of about 100 kW / kg. For example, a motor generator initially acts as a motor, spinning the flywheel to high speed. A motor uses a low-power source, such as a 100-watt or 1000-watt source (such as a battery). When peak power is needed, the motor windings are disconnected from a low-power source and connected to a low-impedance load (for example, conductive layer 96), thereby converting the kinetic energy accumulated by the flywheel into heat.

Some applications for pulsed deicers include the use of high-resistance electric heaters (for example, a resistive heating element for an automobile windshield de-icer) and therefore may require a high-voltage power supply. For example, an automobile windshield defroster can use from 120 volts to 240 volts. This voltage exceeds the output voltage of a conventional car battery (for example, about 12 volts) and a supercapacitor (for example, about 2.5 volts). Instead of using a battery pack to increase the voltage, you can use inverters or step DC / DC converters to increase the voltage.

Thin electric heating layers, for example, an electrically conductive layer 96 (Fig. 7), are useful for reducing energy consumption and thermal inertia of anti-icing. Examples of materials that can be used as layer 96 include thin metal foils, for example stainless steel foil, titanium foil, copper foil, and aluminum foil. Metal sputtering, alloys, conductive metal oxides, conductive fibers (e.g. carbon fibers), and conductive paints can also be used. Typical layer thickness 96 may be from about 50 nm to about 100 microns; however, other ranges can be used, for example, from 10 nm to 1 mm.

In some cases, the protective layer 98 is able to protect the layer 96 from the adverse environment. For example, layer 98 protects layer 96 from abrasion, erosion, high-speed impacts and / or scratches. The protective layer 98 may be either dielectric or conductive and superimposed directly on the layer 96. For example, the layer 96 may have a relatively high thermal conductivity and a relatively high mechanical strength. Some examples of materials that can be used as the protective layer 98 include TiN, TiCN, tungsten carbide, WC, Al ₂ O ₃ , SiO ₂ , Cr, Ni, CrNi, TiO ₂ and AlTiO. The protective layer 98 can be applied to the layer 96 by spraying, chemical vapor deposition (CVD), physical vapor deposition (PPO) and / or sol-gel methods (for example, using a colloidal suspension of particles of silicon oxide, which gels with the formation solid body). Spraying, as is known to those skilled in the art, may include placing the substrate in a vacuum chamber. The plasma generated by a passive gaseous source (for example, argon) generates an ion bombardment directed at the target on the substrate, which leads to "spraying" of the substrate material. The sprayed material is deposited on the walls of the chamber and on the substrate. CPO and FPO methods are known to those skilled in the art.

в Ур. 1-1, 1-2, 1-4), мощность антиобледенения можно снизить для материалов подложки, имеющих низкую плотность, высокую теплоемкость и/или низкую теплопроводность. Многие полимеры имеют малое произведение (ρ_пc_пλ_п), тогда как металлы имеют большое произведение (ρ_пc_пλ_п). Твердые вспененные материалы также имеют малое произведение (ρ_пc_пλ_п). Стекло имеет произведение (ρ_пc_пλ_п) более высокое, чем у обычного полимера, но сравнительно более низкое, чем у металлов. В зависимости от применения теплоизолятор 94 подложки может иметь толщину примерно от 100 нм до 1 мм, но обычно примерно от 0,1 мм до 20 мм.Since the power consumption of pulsed de-icers may depend on the properties of the substrate (e.g.

in Ur. 1-1, 1-2, 1-4), the power of anti-icing can be reduced for substrate materials having a low density, high heat capacity and / or low thermal conductivity. Many polymers have a small product (ρ _p c _p λ _p ), while metals have a large product (ρ _p c _p λ _p ). Solid foam also has a small product (ρ _p c _p λ _p ). Glass has a product (ρ _p c _p λ _p ) higher than that of a conventional polymer, but relatively lower than that of metals. Depending on the application, the substrate heat insulator 94 may have a thickness of about 100 nm to 1 mm, but usually about 0.1 mm to 20 mm.

FIG. 8 shows an anti-icer heating element 100 according to an embodiment of the invention. The heating element 100 is able to melt the boundary layer of ice on the object, receiving energy pulses, for example, according to the equations of figure 1. For example, power can be supplied to the heating element 100 to terminals 101 and 102, which allows the heating element 100 to melt the boundary layer of ice. The power source may supply power to the heating element 100 to melt the boundary layer of ice. Depending on the application of the heating element 100, melting of the boundary layer of ice may be useful for removing ice from the surface of the object, preventing its formation on the surface and / or for changing the adhesion strength and changing the friction coefficient between the ice and the object. Element 100 can be placed, for example, on, in or near the surface of an object to be cleared of ice.

Pulse de-icing system analysis

The following is an analysis of some characteristics of various pulsed de-icing systems. The values of certain elements are illustrated to show how the heat generated by the heating elements dissipates into ice to remove ice from the object.

FIG. 9 shows a pulsed de-icer 120. Ice 124 adheres to the heat-conducting substrate 126, forming an ice-object interface 122. The heating element is located at the interface 122 (for example, in the substrate 126) to facilitate the supply of energy pulses to the interface 122. Substrate 126 represents, for example, an airplane wing, a windshield, a window, an outside mirror, a car headlight, a wind turbine rotor, a building, a road structure, a bridge, a refrigerator, an antenna, a communication mast, a train, a railway track, a tunnel, a traffic sign, a power line , cable, cable car structure or cable car cable.

Figure 10 shows the distance of heat dissipation over time t (for example, t ₁ and t ₂ ), through ice 124 and substrate 126, under temperature pressure T at the ice-object interface 122. The X-axis 123 shows the distance at right angles to the interface 122 (Fig. 9); and temperature T is plotted on the Y-axis 125. Each t ₁ or t ₂ curve expresses the time for the distance that heat propagates into the heat-conducting substrate 126 and ice 124 on both sides of the interface 122. It is shown that the peak of each curve t ₁ and t ₂ corresponds to the melting point 127 on the Y axis 125, i.e. temperature sufficient to melt the boundary layer of ice at interface 122.

The two curves t ₁ and t ₂ depend on the pulse power, which melts the boundary layer of ice. It is shown that t _{1 is} less than t ₂ and corresponds to a higher energy flux density. Since the pulsed amount of energy supplied under each curve t ₁ and t ₂ is sufficient to melt the boundary layer of ice at interface 122, it is preferable to supply such pulsed energy in accordance with t ₁ to provide a higher energy flux density, but, in general, less power compared to t ₂ .

In particular, we consider the following equation for the scattering time t by the length L in the direction of the X axis 123:

t = L ² / D, (Lv. 10-1)

where D is the coefficient of thermal diffusivity, expressed as

D = λ / ρc, (Lv. 10-2)

where λ is the coefficient of thermal conductivity; ρ is the density of the material; C is the specific heat of the material. The shorter power pulses supplied to the interface 122, heats the thinner boundary layers of ice. By adjusting the duration of the heating power, it is possible to better focus on the interface 122, where necessary. The time t and the energy Q supplied to the interface for heating the boundary layer of ice 124 from the ambient temperature T to the melting point 127 satisfy the equations considered in connection with FIG. According to the equations of FIG. 1, removing ice with the device 120 can save energy. In addition, the time t between the heating pulses can be adjusted in accordance with the ice rise rate and the permissible ice thickness. For example, when the ice thickness on the wing of the aircraft reaches about 3 mm, the feedback mechanism allows the device 120 to remove ice 124 as discussed in connection with Fig.6.

11 shows the dependence of the time of removal of ice and the energy of removal of ice (for example, thermal energy) on the density of the heating power for one pulse de-icing system used for a car windshield. For example, a 0.5 μm thick layer of conductive indium tin oxide (ITO) applied to one side of a windshield made of glass and measuring 10 cm x 10 cm x 5 mm can be used as a heating element in a pulsed de-icing system. When the ice grows on the windshield to a thickness of about 2 cm at an external temperature of about -10 ° C, AC power pulses of about 60 Hz frequency are fed to the heating element to heat the boundary layer of ice. When the boundary layer of ice is melted, gravity can remove ice. The thermal energy Q needed to melt the boundary layer of ice may depend on the time and power density with which power is supplied to the heating element. Figure 11 shows such a relationship, where the time of ice removal and the energy of removal of ice are plotted along the axis Y 132, and the density of the flow of heating energy W is plotted along the axis X 133; time is expressed in seconds, and energy is in kilojoules / m ² .

The two diagrams 130 and 131 essentially correspond to the theoretical predictions given in Eq. 1-4 in FIG. 1. For example, diagrams 130 and 131 show that the ice removal time is inversely proportional to the square of the energy flux density W, while the thermal energy Q is approximately inversely proportional to the first degree of the energy flux density W. Accordingly, such a pulsed de-icing system reduces the average power supplied to a heating element for removing ice from an object or preventing its formation on it.

HF anti-icing systems

HF anti-icing systems are used, for example, to remove ice from the surface of an object. As mentioned above, RF anti-icing systems can melt the boundary layer of ice at the interface between the object and ice, which allows you to break, modify and / or eliminate the adhesion of ice. After breaking ice, ice can be removed from the surface, for example, by gravity and / or wind.

12 shows an RF anti-icing system 140 according to one embodiment. The RF anti-icing system 140 comprises a bifilar coil 141 mounted on a dielectric substrate 142. Ice and / or snow 143 adhered to the surface 144 of the dielectric substrate 142. The coil 141 may be coated with a dielectric layer to prevent mechanical damage and environmental influences and / or to prevent electrical air breakdown. The turns of the coil 141 are spaced on the dielectric substrate 142 by a distance D. When power is applied to the coil 142, for example, in accordance with the equations of FIG. 1, the RF defrosting system 140 breaks or changes the adhesion of ice and / or snow 143 to the surface 144. Now we describe the illustrative operational characteristics of the RF anti-icing system 140.

Normal ice has a capacity per square meter:

(Ур. 12-1)

(Lv. 12-1)

and RF conductivity per square meter

(Ур. 12-2)

(Lv. 12-2)

where D is expressed in meters, T - in kelvins. Electric breakdown of air occurs at a voltage of V _ol about

V _ol ≈ 2.4 × 10 ⁶ D (m). (Lv. 12-3)

If you calculate at sea level and use an electric field of air breakdown of about 30 kV / cm, then the root mean square value (RMS) of the voltage V _CR is approximately

V ≈ 1,7x10 ⁶ _etc. D (m). (Lv. 12-4)

Preferably, the maximum voltage is determined to be about 70% of V _ol in (Eq. 10-4) for safety reasons. Accordingly, V _max is

V _max = 0.7 ^. 1.7 × 10 ⁶ D (m) ≈ 1.2 × 10 ⁶ D (m). (Lv. 12-5)

Uniting Lv. 12-2 and 12-5, the maximum heating power is

(Ур. 12-6)

(Lv. 12-6)

The ice removal time of the RF anti-icing system 140 is heuristically determined by applying “safe” voltages according to the following equation:

(Ур. 12-7)

(Lv. 12-7)

Suppose that a coil of thickness 0.5 mm is wound in coil 141 and a safe voltage of 600 volts SCZ is applied to it, then the ice removal time of the RF anti-icing system 140 is heuristically determined to be about thirteen seconds to melt the boundary layer of ice 143 on surface 144 at an external temperature of -30 ° C. Other ice removal times are heuristically determined to be about 4.3 seconds at an external temperature of -20 ° C and about 1.2 seconds at an external temperature of -10 ° C.

It was found that the normal ice build-up rate does not exceed 1.5 mm / min. Accordingly, if it is desirable to dump ice 143 from surface 144 approximately every three minutes, the approximate average ice removal capacities can be determined as follows:

1.75 kW / m ² at -30 ° C. (Lv. 12-8)

The power density used to maintain an ice-free dividing strip with a width of 0.2 inches is determined by adding the power density of the protective strip eight inches wide to each of the power densities Ur. 10-8, assuming that the typical power density is 40 kW / m ² . For example, the typical power density for a dividing strip of 5 mm wide with a protective strip of 8 inches wide is defined as follows:

W = 40 (kW / m ² ) -0.2 ′ ′ / 8 ′ ′ = 1 kW / m ² . (Lv. 12-9)

Accordingly, the addition of Ur. 10-9 to power densities 12-8 gives the following results:

4.1 kW / m ² at -30 ° C (Lv. 12-10)

Therefore, the power density of the RF anti-icing system 140 at -30 ° C (for example, 4.1 kW / m ² ) is only about 10% of the power density developed by the known direct current heater.

13 shows another RF anti-icing system 150. The RF anti-icing system 150 comprises a plurality of electrodes 154 mounted on a dielectric substrate 152 in the form of a comb electronic circuit. The RF anti-icing system 150 removes ice 151 from surface 156 by supplying electrical power to the electrodes 154 from the RF AC power source 155. The RF anti-icing system 150 has anti-icing characteristics in which the heating power density essentially depends on the dimensions a and b, where a is the distance between the electrodes 154 and b is the width of the electrode. In one embodiment, electrodes 154 are woven into a mesh.

Shows the electric power supplied to the electrodes 154, electric power lines 153 coming from the electrodes 154. In the RF anti-icing system 150, the conductivity G of the circuit is proportional to the capacitance C of the circuit per square meter due to electric field lines 153 above the dielectric substrate 152. For example,

(Ур. 13-1)

(Lv. 13-1)

where ε ₀ is the dielectric constant of vacuum (for example, ε ₀ = 8.85 · 10 ^-12 F / m), ε is the relative dielectric constant of ice; σ is the electrical conductivity of ice. Putting a = b, we get

(Ур. 13-2)

(Lv. 13-2)

равно а плюс b, также именуемое как период структуры. Среднее электрическое поле Е равноWhere

equal to a plus b, also referred to as the period of the structure. The average electric field E is equal to

, (Ур.13-3)E ≈ V /

, (Lv. 13-3)

where V is the RMS voltage supplied to the circuit of the RF anti-icing system 150. Accordingly, the heating power W per cubic meter is

(Ур. 13-4)

(Lv. 13-4)

Thus, if the maximum heating power W _max is limited in the RF anti-icing system 150 to the maximum possible electric field E _max (for example, breakdown field), then W _max satisfy the equation

W _max ∝ σ ^. l ^. E _max ² . (Lv. 13-5)

. Кроме того, объемная плотность

для W_max не зависит от

, посколькуTherefore, according to this embodiment, W _max increases linearly with growth

. In addition, bulk density

for W _max is independent of

, insofar as

(Ур. 13-6)

(Lv. 13-6)

. Соответственно, Е можно уменьшать, чтобы не было коронного разряда (например, полезно при использовании полимерных подложек и изоляции электродов).Therefore, in order to maintain a constant W, E decreases with growth

. Accordingly, E can be reduced so that there is no corona discharge (for example, useful when using polymer substrates and electrode insulation).

In the experiment, the RF anti-icing system 150 operated at -12 ° C with various heating powers and voltages and with electrodes having dimensions a = b = 75 μm (for example, when coated with a polyimide film 5 μm thick, for example, Kapton Kapton polyimide) . The following results were obtained:

(Ур. 13-7)

(Lv. 13-7)

When specifying new dimensions, a = b = 500 μm (for example, the period of the structure in mm), the voltage supporting the power increases as the square root of the ratio of the new and previous periods of the structure, which gives

(Ур. 13-7)

(Lv. 13-7)

.One advantage of the RF anti-icing system 150 is that its circuit can be fabricated without the use of photolithography, even on curved surfaces. The electric field strength can also decrease at a rate substantially equal to the growth

.

Comb design for use in the RF anti-icing system

Embodiments and analysis of comb schemes that can be used as heating elements in RF anti-icing systems are described below. The heating elements may be able to receive the RF AC power from the AC power source and can be used to melt the boundary layer of ice at the interface. When the boundary layer of ice is melted, the ice can be removed or re-frozen depending on the requirements, for example, as described below in the section "Methods for adjusting the friction coefficient".

определяется улучшенное отношение a/b.On Fig shows the analysis of the RF anti-icing system 140 depicted in Fig.13. In this analysis, for

An improved a / b ratio is determined.

For example,

(Ур. 14-1)

(Lv. 14-1)

where G ′ is the conductivity of one cell. Since the conductivity is proportional to the capacitance, G ′ is proportional to the capacitance of one cell, which is expressed as follows:

(Ур. 14-2)

(Lv. 14-2)

From Ur. 14-2, it is possible to determine the heating power as follows:

(Ур. 14-3)

(Lv. 14-3)

(Ур. 14-4)

(Lv. 14-4)

(например, приближение a ≈ b сравнительно хорошо, поскольку

= a + b). Мощность W нагрева, когда a = b = 0,5

, равна примерно 97% максимальной мощности нагрева W_max. Диаграмма на фиг.14 также иллюстрирует отношения 10% и 90% в соответствующих точках 157 и 158, где мощность нагрева W оказывается равной 17% и 43% максимальной мощности W_max нагрева. Напротив, когда поддерживается постоянное напряжение, увеличение мощности нагрева достигается за счет увеличения ширины электродов, например, размера «b».where 0 ≤ a ≤ 1. According to the diagram in Fig. 14, when E is kept constant, the maximum heating power W _max reaches point 159, where

(for example, the approximation a ≈ b is relatively good, since

= a + b). Heating power W when a = b = 0.5

, equal to approximately 97% of the maximum heating power W _max . The diagram in FIG. 14 also illustrates the relationships of 10% and 90% at the corresponding points 157 and 158, where the heating power W is equal to 17% and 43% of the maximum heating power W _max . On the contrary, when constant voltage is maintained, an increase in heating power is achieved by increasing the width of the electrodes, for example, size "b".

On Fig shows a number of types 160-163 comb scheme. The comb circuit (FIG. 15) can be used in an anti-icing system, for example, described in the “HF anti-icing systems” section and “pulse anti-icing systems” section. The comb circuit (view 160) is initially mounted by hard anodizing one side (for example, “hard anodized layer 172”) of the thick aluminum foil 171. The hard anodized aluminum foil 171/172 is attached to the polymer substrate 174 using adhesive 173 (view 161). By attaching the hard-anodized aluminum foil 171/172 to the polymer substrate 174, electrodes are formed by etching and / or lithography of the aluminum foil 171 from the general structure (view 162), for example, lithographed edges 175). After that, the structure is bent or adjusted to the desired shape, depending on the choice of design. The remaining open side of the aluminum foil 171 is rigidly anodized to encapsulate the formed electrodes and to seal cracks in the hard anodized layer 172 that occur during bending, as shown in view 163.

Views 160-163 show one method of forming a comb pattern, other methods of forming a comb pattern are possible. Examples of other methods include etching and / or lithography of copper foil to form copper electrodes and attaching copper electrodes to a kapton substrate. An example of a copper comb circuit on a kapton substrate is shown in FIG.

FIG. 16 shows two views of a comb circuit 180 according to one embodiment. The comb circuit 180 comprises a copper anode 181, a comb electrode 182, a copper cathode 183, and a kapton substrate 184. A comb circuit may be formed similar to that shown in FIG. View 185 is a top view. According to view 186, the pitch of the comb circuit 180 defines the distal gap between the electrodes of the comb electrode 182. The pitch of the comb circuit 180 may also determine the distal gap between the electrodes of the copper anode 181. The shift of the comb circuit 180 defines the gap between the electrodes of the comb electrode 182 and the electrodes of the copper anode 181. The width of the comb circuit 180 determines the size of the width of the electrodes of the anode 181. The width of the comb circuit 180 can also determine the size of the width of the electrodes of the comb electrode 182.

The ridge circuit 180 can be used to change the friction between the object and the ice and / or snow by applying electrical voltage to the ridge electrode 182. For example, direct current can be supplied to the ridge electrode 182 according to the equations of FIG. 1. In another example, alternating current can be supplied to comb electrode 182.

The ridge pattern 180 changes the coefficient of friction of the interface between the surface of the object and ice in combination with the natural change in friction between the object and ice or snow with temperature. For example, a “sliding body” steel object slides on ice at a speed of 3.14 m / s, the friction coefficient of a sliding body on ice drops from 0.025 at -15 ° C to 0.01 at -1 ° C. To increase the temperature of the ice in direct contact with the sliding body, the comb circuit 180 can either directly heat the ice using RF electric fields, or heat the surface of the sliding body.

Ridge circuit 180 may be mounted on the surface of a sliding body, which is usually in contact with ice and snow. To heat the surface of the sliding body, a voltage of direct or alternating current can be supplied to the comb circuit 180. For example, by supplying electric power to the surface of a sliding body in accordance with the equations (FIG. 1), it is possible to heat ice and / or the surface and change the coefficient of friction between the surface of the sliding body and ice.

An RF electrical AC power is supplied to the comb circuit 180 to directly heat the ice. When RF power arrives at the electrodes of the comb circuit 180, electric field lines, for example, electric field lines 153 (Fig. 15), penetrate the boundary layer of ice and generate heat in ice in the amount of

_N W = σ ^_l. E ² , (Lv. 16-1)

where W _n - heating power in watts per cubic meter; σ _l - electrical conductivity of ice; E is the electric field strength. An electric field penetrates ice or snow to a depth approximately equal to the distance or step between the electrodes of the comb circuit 180. Accordingly, the heating power W _n satisfies the equation

(Ур. 16-2)

(Lv. 16-2)

where V - RMS AC voltage. Power W _n in Ur. 16-2 indicates electrical power per unit volume, but it is more important to know the power W per square meter of the ice / sliding object interface. To estimate the power per square meter W _sq , you need to multiply the power W _n by the thickness of the heated layer, approximately d, as described above. Therefore, the power per square meter W _sq is expressed by the equation

. (Ур. 16-3)

. (Lv. 16-3)

The heating power per square meter W _kV may be limited by the electric breakdown of air occurring at an electric field strength E _pr , therefore

. (Ур. 16-4)

. (Lv. 16-4)

From Ur. 16-3 and 16-4, we can derive the ratio for the maximum power of heating by a high-frequency field per unit area of a moving object:

W _q ≤ σ ^_l. d ^. E _ol ² . (Lv. 16-5)

For practically pure ice at -10 ° C, the electrical conductivity of ice at high frequencies (e.g., above 10 kHz) is approximately 2 × 10 ^-5 S / m. Substituting in ur. 16-5 conductivity values σ _n, the electric field E and the _straight distance d ≈ 0,25 mm (e.g., a typical size in the HF deicer), can obtain the maximum power limit RF heating:

W _sq ≤ 45 kW / m ² . (Lv. 16-6)

A more accurate power value used to increase the temperature of the boundary layer of ice by ΔT can be calculated according to the following equation:

_р ^.a^.v^.ρ^.C^.ΔT, (Ур. 16-7)W _speed =

^_p. a ^. v ^. ρ ^{. C.} ΔT, (Lv. 16-7)

where v is the speed of the moving body; ρ is the density of ice or snow; a is the width of the moving body; C is the specific heat of ice; l _p - the length of heat dissipation in ice or in snow. The heat dissipation length l _p is expressed as

, (Ур. 16-8)

, (Lv. 16-8)

where t is the time during which a particular section of ice is in contact with a moving body, expressed as

, (Ур. 16-9)

, (Lv. 16-9)

where L is the length of the moving body, and D is the heat dissipation coefficient, expressed as

, (Ур. 16-10)

, (Lv. 16-10)

where λ is the coefficient of thermal conductivity of ice or snow. Substituting ur. 16-8, 16-9 and 16-10 in Ur. 16-7, we obtain the following estimate for changing the coefficient of friction between ice and a moving body:

. (Ур. 16-11)

. (Lv. 16-11)

As a practical digital example, for two skis with a total width of about a = 10 ⁻¹ m and a length L = 1.5 m, a ridge pattern 180 can be used to change the coefficient of friction between skis and snow. Let's say the skis move at a speed of v = 10 m / s. The snow density ρ is

ρ = 3 ^. 10 ² kg / m ² , (Lv. 16-12)

the change in temperature of the boundary layer of snow ΔT is equal to

ΔT = 1 ° C, (Lv. 16-13)

the specific heat of snow C is

C = 2 ^. 10 ³ J / kg ^. K. (Lv. 16-14)

Based on these values, you can calculate the estimate of energy consumption W _speed :

W _speed = 134 watts. (Lv. 16-15)

Since only a small fraction of the skis can actually be in contact with snow at any given moment in time, the estimate of energy consumption W _scor can be further reduced to a fraction of W _scor or W _scor-share as follows:

(Ур. 16-16)

(Lv. 16-16)

where W is the weight of the skier; N is the compressive strength of snow in pascals (Pa). For a heavy skier (for example, 100 kg) and H = 105 Pa W, the _{speed-proportion} will be

W _{speed ratio} ≈ 6.6%. (Lv. 16-17)

Accordingly, the RF power required to change the coefficient of friction will be

W _speed = 134 W × 0.066 ≈ 9 W. (Lv. 16-18)

Although this embodiment shows an example of the application of a comb pattern 180 (e.g., for skiing), it will be apparent to those skilled in the art that the comb pattern can be used to change the coefficient of friction between ice and the surfaces of other objects, including, for example, snowboards and snowshoes.

RF anti-icing system analysis

Below is an analysis and some operational characteristics of various RF anti-icing systems. The values of certain components are varied to illustrate various conditions, for example, changing environmental conditions and / or changing modes of heat transfer.

On Fig shows a diagram 190 of the frequency dependence of the electrical conductivity of the ice and the dielectric constant of the ice. Permeability ε is plotted along Y-axis 193, and frequency is plotted along X-axis 194. Diagram 190 also shows the RF heating power for comb designs, such as comb designs 180 (FIG. 16).

When the electrically conductive material is in the electric field E, a bulk heat density W is generated, expressed as follows:

W = σE ² , (Lv. 17-1)

where σ is the electrical conductivity of the material (for example, the electrical conductivity of ice). From Ur. 17-1 it appears that the heat density is proportional to the electrical conductivity and the square of the electric field strength. Therefore, to increase the heating rate and, therefore, reduce the time for removing ice, it is possible to increase the electrical conductivity of ice and / or electric field strength.

The electrical conductivity of ice depends on temperature, frequency and impurities in the ice. The electrical conductivity of ice increases by adjusting the frequency of the AC power used to change the coefficient of friction between the ice and the surface of the object. In this case, the frequency dependence of the electrical conductivity of ice can be expressed as follows:

(Ур. 17-2)

(Lv. 17-2)

where σ _s and σ _∞ are the static and HF electrical conductivities of ice, respectively; ω is the circular frequency of the AC power; τ _D is the dielectric relaxation time for ice.

According to diagram 190, the electrical conductivity changes with increasing frequency under temperature conditions of about -10.1 ° C. For example, in accordance with curve 191, electrical conductivity increases with increasing frequency, and in accordance with curve 192, electrical conductivity decreases with increasing frequency. Accordingly, curves 191 and 192 illustrate various methods for changing the electrical conductivity of the ice-object interface by adjusting the frequency of the RF heating power.

According to diagram 190, at -10.1 ° C, ice has an electrical conductivity of about 0.1 S / m at a frequency of about 10 kHz. The electrical conductivity of ice decreases exponentially with decreasing temperature. Accordingly, the electrical conductivity of ice at -30 ° C will be approximately an order of magnitude less than the electrical conductivity of ice at -10 ° C.

The dimensions of the RF anti-icer heating element, such as the comb circuit 180 (FIG. 16), may depend on the electrical conductivity of the ice and the desired heating rate. Accordingly, when generating the amount of heat per square meter W ′ in the thickness of the boundary layer of ice using the applied voltage V at a distance d between the electrodes, the electric field strength E is expressed by the equation

E = V / d. (Lv. 17-3)

The amount of heat per square meter W ′ is determined

W '= Wd. (Lv. 17-4)

Combining Lv. From 17-1 to 17-4, we obtain the following expression for the heating power per square meter:

W '= σV ² / d. (Lv. 17-5)

For example, the typical heating density for an automobile windshield is about 1 kW / m ² and the voltage V is about 100 volts. Using these values and the value of the electrical conductivity of ice, we obtain from Ur. 17-5 a value of about 0.1 mm for the step between the electrodes. In other embodiments, a different value may be obtained.

On Fig shows an illustrative circuit 200, characterizing the RF deicer according to one variant of implementation. The circuit 200 includes an AC power source 201, a capacitor 203, a capacitor 204, a resistor 202 and a resistor 205. The resistor 202 is connected to a power source 201 and a capacitor 203 and has a resistance R _ext expressing the internal resistance of the power source 201. The resistor 205 is connected in parallel with the capacitor 204 and has a resistance R _l expressing the resistance of the ice. The capacitor 204 has a capacity C _l expressing the capacity of the ice layer. The capacitor 203 is connected to the resistor 205 and the capacitor 204 and has a capacitance C _d expressing the capacity of the protective dielectric layer on the anti-icing electrodes, for example, coil 141 (Fig. 12). Circuit 200 is a circuit diagram for modeling and analysis of some de-icing systems.

Figs. 19-23 are diagrams illustrating some test analyzes of the circuit 200 according to one embodiment, in which the circuit 200 has a dielectric layer surrounding the electrodes (for example, a circuit such as a comb circuit 180, Fig. 16, with a dielectric layer surrounding electrodes). In this environment, circuit 200 can be characterized using Table 19-1:

Table 19-1 ε ₀ = 8.85 ^. 10 ¹² f = 10, 100 .. 1 ^. May ¹⁰ ω (f) = 2πf T = 243, 244 .. 273

ε _s (T) = 25047 / T ε _inf = 3,2

σ ₀ = 10 ^-8

d = 10 ^-7 , 2 ^. 10 ^-7 ..3 ^. 10 ^-5 ε _d = 9.9

= 2.5 ^. 10 ^-4 V = 500 R _int = 0

P _L (f, T, d) = V. Re (I (f, T, d)) ε _in = 80 σ _in = 5 ^. 10 ^-4

_A P (f, d) = ^V. Re (I _in (f, d))

where ε ₀ is the dielectric constant of the vacuum; f is the increasing frequency; ω is the circular frequency as a function of f; T is the increasing external temperature in K; τ _D is the relaxation time of the dielectric for ice; ε _s is the static dielectric constant of ice; ε _inf is the high-frequency dielectric constant of ice; σ _inf is the high-frequency electrical conductivity of ice; σ ₀ - static electrical conductivity of ice; ε is the dielectric constant of ice (for example, as a function of frequency f and temperature T); σ is the electrical conductivity of ice (for example, as a function of frequency f and temperature T); d is the thickness of the protective dielectric layer; ε _d is the dielectric constant of the protective dielectric layer l; V is the voltage; Z _l - ice impedance (for example, as a function of frequency f, temperature T and distance d); Z (f, T, d) is the total impedance of the circuit, including ice covering the electrodes (for example, as a function of frequency f, temperature T and distance d); I is the supplied current (for example, as a function of frequency f, temperature T and distance d); P _l - power supplied to heat the ice (for example, as a function of frequency f, temperature T and distance d); ε _in - dielectric constant of water; C _in - water capacity; Z (T, d) is the total impedance of the circuit, including water covering the electrodes (for example, as a function of frequency f and distance d); I _in - supplied current (for example, as a function of frequency f and distance d); P _in - power entering the water (for example, as a function of frequency f and distance d). The electrical power was calculated for both of the following cases: when the ice covers the electrodes and when the ice has melted and the water contacts the electrodes.

On Fig shows the dependence of the heating power generated in distilled water (chart 210) at 20 ° C and in ice (chart 211) at -10 ° C on the thickness of the dielectric coating of the electrodes. In Fig.19, the heating power per m ^{2 is} plotted on the Y-axis 213, and the thickness of the dielectric coating in meters is plotted on the X-axis 212. According to this embodiment, the coating is an alumina coating. The frequency of the AC power is about 2 kHz at a voltage of about 500 volts RMS. With a coating thickness of about 25 μm, the heating power for water and ice is approximately the same.

On Fig shows the dependence of the heating power generated in distilled water (chart 220) at 20 ° C and in ice (chart 221) at -10 ° C on frequency. In Fig.20, the heating power in W / m ^{2 is} plotted along the Y-axis 223, and the frequency in Hz is plotted along the X-axis 222. At a frequency of about 20 kHz, the heating powers for water and ice are equal. This is useful for matching heating capacities for water and ice to avoid cold or hot patches on the defroster where the ice is melting.

On Fig shows the dependence of the heating power generated in ice (diagram 230) on temperature. In Fig.21, the heating power in W / m ^{2 is} plotted along the Y-axis 231, and the temperature in ° K is plotted along the X-axis 232. Accordingly, the dielectric coating on the electrodes of the RF anti-icer can be used to adjust the performance of the anti-icer.

On Fig shows the dependence of the heat transfer coefficient (W / m ^2. K) on the air velocity (m / s) (chart 240). In FIG. 22, the heat transfer coefficient is plotted along the Y 241 axis, and the velocity v is plotted along the X 242 axis. FIG. 22 may assist in determining RF power to remove ice and / or prevent ice formation on a flat windshield. The size of the windshield is 0.5 m in the described embodiment, the circuit 200 acts as an RF anti-icer in the ice removal mode and in the mode of preventing ice formation on the windshield. Table 19-2 shows the MathCad file used to calculate the convective heat transfer coefficient for a car windshield:

Table 19-2 v = 1, 1,1 .. 30 L = 0.1, 0.2 .. 1 Re _tr = 10 ⁵ ν = 1.42 ^. 10 ^-5

k = 0,0235 Pr = 0.69 Re _L (20, 0.5) = 7.042 × 10 ⁵

where v is the speed of the car; L is the length of the surface of the windshield; Re - Reynolds number range from 105 to 107; h (v, L) is the heat transfer coefficient (for example, as a function of speed and L); k is the coefficient of thermal conductivity of air; Pr is the Prandtl number for air; ν is the kinematic viscosity coefficient of air. In this embodiment, the heat transfer coefficient h (v, L) at a speed of about 30 m / s and a length of about 0.5 meters is 89.389 W / m ^2. K. Accordingly, FIG. 22 graphically shows (diagram 240) the relationship between the heat transfer coefficient h (v, L) and air velocity.

On Fig shows the dependence of the minimum RF power W _min circuit 200 from the external temperature T (in ° C) for vehicle speeds of 10 m / s (chart 252), 20 m / s (chart 251) and 30 m / s (chart 250 ) 23, the minimum HF power W _min in W / m ^{2 is} plotted along the Y axis 253, and the temperature T is plotted along the X 254 axis. The minimum heating power W _min to maintain the outer surface of the windshield at a temperature of about 1 ° C is shown in Table 19 -3 (MathCad file):

Table 19-3 S = 0, 0.1 .. 2 T = 0, -1 .. -30 W _min (v, L, T, S) = h (v, L) ^{. S.} (1-T), where S is the area of the windshield.

Accordingly, diagrams 250, 251, and 252 may assist in making decisions regarding power supplied in accordance with vehicle speed v using circuit 200.

Figs. 24-26 graphically illustrate another analysis of the circuit 200 (Fig. 18), in which the circuit 200 has a dielectric layer covering the electrodes (for example, a comb circuit 180 (Fig. 16) with a dielectric layer covering the electrodes). In this embodiment, the circuit 200 can be characterized using Table 24-1 (MathCad file):

Table 24-1 ε ₀ = 8.85 ^. 10 ^-12 f = 10, 100 .. 1 ^. May ¹⁰ ω (f) = 2πf T = 243, 244 .. 273

ε _s (T) = 25047 / T ε _inf = 3,2

σ ₀ = 10 ^-8

d = 10 ^-7 , 2 ^. 10 ^-7 .. 3 ^. 10 ^-5 ε _d = 9.9

l = 2.5 ^. 10 ^-4 V = 500 R _int = 0

P _L (f, T, d) = V. Re (I (f, T, d)) ε _in = 80 σ _in = 5 ^. 10 ^-4

_A P (f, d): = V . Re (I _in (f, d))

where the variables are the same as in Table 19-1, but with different values. For example, σ _in is the electrical conductivity of water with the same value of 5x10 ^-4 S / m.

Fig.24-26 graphically illustrate the dependence of the heating power generated in distilled water (diagrams 261, 270, 281 corresponding to Fig. 24, 25 and 26) at 20 ° C and in ice (graphs 260, 271, 280 corresponding to Fig. 24, 25 and 26) at -10 ° C, which differ in the thickness of the dielectric layer: 10 ^-5 m (Fig. 24), 10 ^-6 m (Fig. 25), 2 ^. 10 ^-5 m (Fig. 26). The heating power shown in FIG. 24, 25 and 26, depends on the frequency of the AC power. As the frequency increases, the amount of supplied power used to melt the boundary layer of ice is leveled. The AC voltage is about 500 V. With a coating thickness of about 10 μm (10 ⁻⁵ m), the corresponding heating power for water and ice is almost equal, as shown in FIG. 24.

Figs. 27-29 graphically illustrate some test analyzes of circuit 200 in which circuit 200 is applied to a sliding body, described in detail below. In this embodiment, the change in snow temperature under the moving body is taken into account. Scheme 200 can be characterized by the following Table 26-1 (MathCad file):

Table 27-1 ρ = 300 kg / m ³ x = 0, 0.0001 .. 0.1 m C = 2 ^. 10 ³ J / kg ^. K λ = 0.2 W / m ^2. K W = 1 ^. 10 ³ W / m ²

D = 3.333 × 10 ^-7

t = 0, 0.001 .. 1 s a = 0.1 m L = 1.5 m v = 1, 2 .. 30

w _speed (1.10) = 134.164 W

where ρ is the density of snow; x is the distance in the snow from the moving body; C is the heat capacity of snow; λ is the coefficient of thermal conductivity of snow; W is the heating power; D is the coefficient of thermal diffusivity of snow; t is the duration of the power supply; a is the width of the moving body; L is the length of the moving body; v is the speed of the moving body; y is the integration variable; W _spd - heating power with respect to the moving velocity of the body; Δ is the superheat temperature.

On Fig shows the dependence of the temperature of the superheat Δ (for example, in ° C) on the distance to the sliding body. In Fig.27, the superheat temperature Δ (° C) is plotted on the Y 295 axis, and the distance from the moving body (in meters) is plotted on the X 294 axis. With a heating power W of about 1 kW / m ^{2, the} diagrams 290, 291, 292 and 293 illustrate the temperature dependences of the heating pulses having approximate durations t = 0.1 s, 0.2 s, 0.5 s and 1 s, respectively. On Fig shows the dependence of the temperature of the interface of the snow / sliding object from time to time (diagram 300) when applying RF power with a density of 1000 W / m ² . 28, the superheat temperature Δ (° C) is plotted on the Y-axis 301, and the time (in seconds) is shown on the X-axis 302.

On Fig presents the heating power necessary to increase the temperature of the interface by 1 ° C when moving a sliding body with a speed v of about 30 m / s. 29 is a Y-axis 311 plotted heating power W _{is swift,} and 312 in the X axis represents the speed v. In this example, when a sliding body moves at a speed of about 5 m / s, the heating power is about 100 watts. The heating power W speed _spd is constructed as a function of v (plot 310).

30-35 are diagrams illustrating heat transfer analysis by convection for an anti-icing system and heat transfer through a substrate for an RF anti-icing system. In this example, a stationary solution, for example constant power, is illustratively characterized. On Fig shows the dependence of the heat transfer coefficient h _k on the air speed (chart 320) under the assumption that the aerodynamic surface is cylindrical (the front edge of the wing of the aircraft). 30, the heat transfer coefficient h _{k is} plotted along the Y 321 axis, and the velocity v is plotted along the X 322 axis. The heat transfer coefficient h _k for the aerodynamic surface can be calculated according to Table 30-1:

Table 30-1 (MathCad File) v = 89 D = 0.03 v = 10, 11 .. 100

h _k (89, 0.254) = 141.057 watt / m ^2. K h _k (89, 0.0254) = 330.669 watt / m ^2. K

where v is the air velocity; D is the diameter of the aerodynamic surface. About half of the heat transfer coefficient h can be attributed to the front portion of the aerodynamic surface using a Reynolds number of about 1.9x10 ⁵ .

The thermal conductivity coefficient h _{k is} about 165 W / m ^2. K used in the RF anti-icer generates a power W of about 4.5 kW per square meter. The deicer contains a polymer layer of thickness d with a thermal conductivity coefficient λ _d . Ice builds up on the de-icer with a thickness of L. The thermal conductivity of the ice is λ, and the thickness of the heated boundary layer of ice is approximately equal to one interelectrode distance, i.e. about 0.25 mm. The static temperature of the overheating of the boundary layer of ice Δ = T _gr -T _int , where T _gr is the temperature of the boundary, T _int is the external temperature, can be calculated according to Table 30-2 (MathCad file):

Table 30-2 W = 4500 W / m ² d = 0.002 m h = 165 W / m ^2. K L = 0, 0.0001 .. 0.01 m l = 0.00001, 0.00002 .. 0.001 m λ _l = 2.22 W / m ^. K λ _d = 0.35 W / m ^. K

On Fig shows the dependence of overheating Δ in ° C stationary state (stationary solution) on the thickness of the ice in meters. 31, the superheat Δ is plotted along the Y axis 335 and the thickness L is plotted along the X axis 336. Diagram 330 shows the dependence of the stationary state superheat in ° C on the ice thickness in meters, assuming there is a theoretically perfect insulating layer between the de-icer and the aerodynamic surface, and diagram 331 shows the relationship in the presence of a 2 mm thick Teflon film between the de-icer and the aerodynamic surface. The de-icing performance reaches its maximum when the ice thickness exceeds about 1 mm (point 333 for a theoretically perfect insulating layer and point 334 for a 2 mm thick Teflon film).

электрода. В данном примере можно наблюдать кипение в пограничном слое льда. Кипение объясняется испарением льда (например, пар) и свидетельствует о перегреве более чем на 110°C.On Fig shows the dependence of the superheat Δ in ° C stationary state on the size of the electrode in meters (chart 340), assuming the presence of a perfect insulating layer and an ice thickness of 1 mm On Fig on the axis Y 341 delayed overheating Δ, and on the axis X 342 delayed size

electrode. In this example, boiling in the boundary layer of ice can be observed. Boiling is explained by the evaporation of ice (e.g. steam) and indicates overheating by more than 110 ° C.

During operation, the de-icer may have a higher productivity than in laboratory conditions. For example, the physical properties of atmospheric ice growing on an aerodynamic surface are different than those of solid ice. Atmospheric ice may contain unfrozen water and / or gas bubbles. These atmospheric ice inclusions can reduce thermal conductivity and ice density. For example, the thermal conductivity of water is about 0.56 W / m ^. K, and the thermal conductivity of solid ice is about 2.22 W / m ^. K, the boundary layer of ice (for example, an ice layer adjacent to the de-icer) is warmer than the rest of the ice and may contain water.

The heat defrosting device used can be modeled by approximating the thermal conductivity coefficient of ice λ with a number within 0.5 W / m ^. K up to 2.22 W / m ^. K. An example is calculated according to Table 30-3:

Table 30-3 W = 4500 W / m ² d = 0.002 m h = 165 W / m ^2. K L = 0, 0.0001 ... 0.01 m l = 0.00001, 0.00002 ... 0.001 m λ = 1 W / m ^. K λ _d = 0.35 W / m ^. K

On Fig shows the dependence of the superheat Δ in ° C stationary state (stationary solution) on the thickness of the ice in meters. 33, the superheat Δ is plotted along the Y 355 axis and the thickness L is plotted along the X 356 axis. Diagram 350 shows the dependence of the stationary state superheat in ° C on the ice thickness in meters, assuming there is a theoretically perfect insulating layer between the de-icer and the aerodynamic surface, and diagram 351 shows the relationship in the presence of a 2 mm thick Teflon film between the de-icer and the aerodynamic surface. The de-icing performance reaches its maximum when the ice thickness exceeds about 1 mm (point 352 for a theoretically perfect insulating layer and point 353 for a Teflon film 2 mm thick).

An inhomogeneous distribution of electrical power near de-icing electrodes can also cause boiling of the boundary layer of ice. For example, the local power density on the electrode surface can exceed the average power by about an order of magnitude due to fluctuations in the electric field strength. Moreover, in those places where the power exceeds the average power, the electrode can heat the boundary layer of ice faster than in other places, with the formation of steam.

The results of a time-dependent solution may differ from the results of stationary solutions. For example, since ice is a material with a low coefficient of thermal conductivity when applying RF power to the boundary layer of ice, a “heat wave” propagates through ice. Accordingly, a thin layer of ice can be considered a thermally insulated layer of ice. In this case, the de-icer can supply power mainly only in this layer. The time-dependent temperature curves Δ (x, t) (diagrams 360, 361, 362 and 363 of FIG. 34) can be calculated according to Table 30-4:

Table 30-4 (MathCad File) ρ = 920 kg / m ³ C = 2 ^. 10 ³ J / kg ^. K x = 0, 0.0001 ... 0.1 m λ = 1 W / m ^. K W = 4.5 ^. 10 ³ W / m ² D = λ / ρ ^. C

t = 0, 0.1 .. 1000 s D = 5,435 × 10 ^-7

where ρ is the density of ice; C is the heat capacity of ice; λ is the coefficient of thermal conductivity of ice; x is the distance from the heater; W is the supplied power per square meter, D is the coefficient of thermal conductivity; and t is the duration of the power supply (for example, in a heating pulse). On Fig shows diagrams 360, 361, 362 and 363 for the corresponding values of time 200 s, 100 s, 25 s and 5 s, when the power W of about 4.5 kW / m ² enters the atmospheric ice, which is a mixture of solid ice, unfrozen water and gas bubbles having a thermal conductivity of 1 W / m ^. K. In Fig. 34, overheating Δ is plotted on the Y-axis 365, and the distance x from the heater is plotted on the X-axis 366.

The temperature of the boundary layer (i.e. the temperature of the boundary layer of ice) has a typical scattering time T calculated according to Table 30-5:

Table 30-5 L = 10 τ = L ² / D τ = 184 s

On Fig shows the dependence of the temperature of the interface on time, showing the dependence of the boundary temperature of the superheat Δ in ° C from time to time. In Fig. 35, the superheat temperature Δ is plotted on the Y-axis 371, and time is plotted on the X-axis 372. By applying a short heating pulse, thermal energy can be minimized and the boundary layer of ice can still be melted. For example, thermal energy can be calculated according to Table 30-6:

Table 30-6 (MathCad File)

where t is the time required to achieve the desired superheat temperature Δ of the boundary layer of ice; Q is the total thermal energy needed to reach this temperature. As in FIG. 1, the total thermal energy Q can be substantially inversely proportional to the supplied power W, so that the defroster has a higher KPD. and to save full electrical power.

Heat Transfer De-icing Systems

In the following embodiments, heat transfer anti-icing systems are described. Heat transfer de-icing systems can be used to remove ice from the surface of an object. In some embodiments, the implementation of the system can be used to melt the boundary layer of ice and change the coefficient of friction at the interface between the surface of the object with ice. Such heat transfer anti-icing systems accumulate heat energy and periodically transfer heat energy from a heat source (or heat source) to a heating element.

On Fig shows a de-icing system 460 with heat transfer. The 460 anti-icing system with heat transfer is presented in two states - 460A and 460B. The heat transfer anti-icing system 460 includes a power source 464, a heat insulator 462, a heating element 466, a membrane 470, and a membrane valve 468. The heat transfer anti-icing system 460 is capable of removing ice 472 from the surface (e.g., including the outer surface 471 of the membrane 470) of an object, e.g., an airplane, an airplane wing, a car windshield, a boat, an airplane, a road, a sidewalk, a freezer, a refrigerator, a treadmill, and a window. The heat-transfer de-icing system 460 can provide heat storage, which allows to supply, as necessary, the stored heat in the form of thermal pulses to the ice-object interface. Power supply 464 may include a switching power supply, a battery, a capacitor, a flywheel, and / or a high voltage power supply. A supercapacitor or an ultracapacitor can be used as a capacitor.

In state 460A, the membrane 470 is inflated with gas through the membrane valve 468. As a gas, you can use air or other gases with the property of thermal insulation. When power is supplied to the heating element 466, the power is converted to a certain amount of thermal energy, which is stored in the heating element 466. The thermal energy stored in the heating element 466 is transferred to the boundary layer 473 by blowing off the membrane 470, as shown in state 460B. By blowing off the membrane 470, thermal energy is transferred from the heating element 466 to the boundary layer 473 to melt the boundary layer 473, thereby removing ice 472. State 460B is maintained for as long as necessary to melt the boundary layer of ice 472.

On Fig shows the de-icing system 480 with heat transfer. The 480 anti-icing system with heat transfer is illustrated in two states - 480A and 480B. The heat transfer anti-icing system 480 includes a power supply 484, a heat insulator 486, and a heating element 482. The heat transfer anti-icing system 480 is capable of removing ice 492 from the surface 491 of the object 493. The object 493 may belong to the class of objects discussed above. The heat-transfer de-icing system 480 can provide heat storage, which allows, as necessary, to supply stored heat in the form of heat pulses to the ice-object interface to melt the boundary ice.

In state 480A, the heating element 482 is shown in the form of two layers 482A and 482B, between which a heat insulator 486 is enclosed. The heat insulator 486 is movably mounted between the layers 482A and 482B of the heating element, which allows these layers to come into contact with each other when sliding, as shown in the state 480V. The power source 484 supplies a certain amount of power to the heating element 482. One or more power sources can act as a power source. When power is supplied to the heating element 482, power is converted to thermal energy. When layer 482A comes into contact with layer 482B, thermal energy is transferred from the heating element 482 to the boundary layer of ice 492 in an amount sufficient to melt this boundary layer. The layers 482A and 482B of the heating element often move relative to each other, as a result of which the heat insulator 486 periodically insulates layers 482A and 482B and causes periodic transfer of thermal energy to the boundary layer of ice on the surface 491. Periodic transfer of thermal energy provides medium energy to the boundary layer for keeping the object free of ice.

The heating element 482 may be made of a conductive material, for example, in the form of a foil of metal or a metal alloy, a thin layer of metal on a dielectric substrate, a thin layer of metal oxide on a substrate, a conductive polymer film, conductive paint, conductive adhesive, wire mesh and conductive fibers . Examples of transparent conductors include SnO ₂ , ITO, TiN and ZnO. Examples of conductive fibers include carbon fibers.

On Fig shows a de-icing system 500 with heat transfer. The heat transfer anti-icing system 500 includes a power source 504, a heating element 502, a water pump 508, a tank 506, and a tube 510. The heat transfer anti-icing system 500 is capable of removing ice 512 from an object surface 511. The heat transfer anti-icing system 500 is able to act as a heat storage device, which allows the accumulated heat to be supplied as a heat pulse to the ice-object interface on the surface 511. When power is supplied to the heating element 502, the power is converted to thermal energy. The heating element 502 raises the temperature of the heat transfer fluid in the tank 506. Water or other heat transfer fluid may be used as the heat transfer fluid. Pump 508 pumps heat-conducting fluid through tube 510. When heat-conducting fluid is pumped into tube 510, thermal energy is transferred to the boundary ice layer 512 on surface 511. As a result of the transfer of thermal energy to the boundary layer, ice 512 detaches from surface 511. According to one embodiment, pump 508 often pumps heat-conducting fluid through a tube 510, causing periodic transfer of thermal energy to the boundary layer in order to supply the average thermal energy necessary to maintain the object to the interface ice-free.

On Fig shows a pulse de-icing system 520, which shows the differences between de-icing systems with heat transfer (Fig. 37 and 38) from the previously described systems, for example system 10 (Fig.1). In this embodiment, ice 528 adheres to surface 531 at an object-ice interface adjacent to surface 531. Pulse de-icing system 520 comprises a power supply 524, one or more heating elements 526, and layers 522A and 522B. Pulse de-icing system 520 is capable of removing ice 528 from surface 531 of layer 522B. For example, layer 522B is the windshield from which ice needs to be removed.

Heating elements 526 are embedded in layer 522B and are electrically connected to power supply 524 to receive power from it. Layers 522A and 522B are made of a substantially transparent material for use in or as a windshield.

When the power supply 524 supplies power to the heating elements 526 (which may also be transparent), thermal energy is radiated from the heating elements 526 and disrupts the adhesion of ice 528 to the surface 531 of layer 522B. A power source 524 supplies power to the heating elements 526 according to the equations of FIG. 1. As the power source 524, one or more power sources can be used, for example, as in FIG.

When power is supplied to the heating elements 526, power is converted to a certain amount of thermal energy. Thermal energy is transferred to the boundary layer of ice 528 on the surface 531 to prevent ice 528 from sticking to the surface 531. Power is transmitted to the heating elements 526 by frequent pulses for the periodic transfer of thermal energy to the boundary layer during the periods expressed by Eq. 1-1.

For comparison, a power source of the anti-icing system with heat transfer, for example, power sources 484 and 504 (FIGS. 37 and 38), supply power to the heating elements, which in turn generate thermal energy. An anti-icing system with heat transfer retains thermal energy until heat is supplied to the ice-object interface.

The heating elements 526 of the pulse anti-icing system 520 can be made, for example, of a metal alloy foil, a thin layer of metal on a dielectric substrate, a thin layer of metal oxide on the substrate, an almost transparent conductor, a conductive polymer film, a conductive paint, a conductive adhesive, a wire mesh and / or conductive fibers. Examples of transparent conductors include SnO ₂ , ITO, TiN and ZnO. Examples of conductive fibers include carbon fibers. Heating elements 526 may also include semiconductor devices capable of converting power to thermal energy. Through the use of multiple heating elements 526, the total energy consumption can be segmented or determined individually. For example, segment 535 of surface 531 requires significantly less energy to melt the boundary layer of ice in this area compared to melting the boundary layer of ice in this area for the entire surface 531. Accordingly, the instantaneous energy consumption for breaking ice sticking 528 decreases when the sequential supply of pulses to the segments or patches leads to partial detachment of ice 528 from the entire surface 531 over time.

On Fig shows the de-icing system 540 with heat transfer. The heat transfer anti-icing system 540 comprises a heat conductor 542 (eg, a “hot plate”), a dielectric plate 546, and a heating element 544 (eg, a thin metal foil). A heat transfer anti-icing system 540 is capable of melting the boundary layer of ice 545 at an object by supplying thermal energy pulses to ice 545. For example, a heat-transfer anti-icing system 540 can be located on the surface of an object, as a result of which a heating power is supplied to the heating element 544 to melt the boundary layer ice 545.

The heat conductor 542 converts the power into heat energy that is transferred from the heat conductor 542 to the heating element 544 through the holes 547 in the dielectric plate 546. In one example, the heat conductor 542 vibrates, whereby when the heat conductor 542 contacts the heating element 544, the conductor 542 heat transfers thermal energy to a heating element 544, which melts the boundary layer of ice. Depending on the use of the heat transfer anti-icing system 540, melting of the boundary layer of ice may be useful to remove ice from the surface of the object, to prevent its formation on the surface, or to change the adhesion strength and change the friction coefficient between the ice and the object.

The heat transfer anti-icing system 540 is used as a “pulse brake” in which a heat pulse is transferred from the heat conductor 542 to the heating element 544 when the heat conductor 542 touches the heating element 544 connected to the base of the sliding body that is adjacent to the ice. If braking is necessary, the heat conductor 542 touches the heating element 544 for several milliseconds through the holes 547 in the dielectric plate 546, creating “hot spots” on which the ice melts. After the heat conductor 542 is removed, the melted spots usually freeze for several milliseconds, providing links between the base of the sliding body and the ice.

One of the parameters of an impulse brake is the time required for melting and subsequent freezing of ice / snow. When boundary cooling occurs between ice or snow and the base of a moving body, the cooling time can be estimated according to the expression:

(Ур. 40-1)

(Lv. 40-1)

where T _t is the melting temperature of ice; T is the external temperature; λ is the coefficient of thermal conductivity; ρ is the density of the material; c is the heat capacity of the material (the subscript “snow” refers to ice and / or snow, and the subscript “ski” refers to the material used as the base of the sliding body); W is the power per square meter; Q is the released heat energy; S is the base area of the moving body.

FIG. 41 shows a heat transfer system 560 that has been implemented and tested in accordance with the embodiment of FIG. 36. According to this embodiment, the heat transfer system 560 comprises two aluminum discs 562 and 563 about six inches in diameter and 1 mm thick. According to one embodiment, the inner surfaces of the discs 562 and 563 are ground and polished to reduce optical emissivity. The outer surfaces of the discs 562 and 563 are anodized in an approximately 15% sulfuric acid solution to produce an alumina film of a thickness of 10 μm to 12 μm (hard anodizing). The disks 562 and 563 are attached to the Plexiglas ring 569 with a rubber O-ring 570B. The disks 562 and 563 are also attached to the Plexiglas ring 572, and thus to the valve 571, by the o-ring 570A.

The heat transfer system 560 also includes a heating element 565 attached to the disk 563 and capable of receiving electrical power from a power source 566 to convert this power to thermal energy. The heating element 565 contains carbon foil encapsulated in a kapton polyimide substrate 568. A thermocouple 564 can be attached to the disk 563 through an opening 579 in the heating element 565 by means of heat-conducting adhesive. In one embodiment, thermocouple 564 is capable of controlling the temperature of disk 562 when heating element 565 transfers heat to disk 563. According to one embodiment, power source 566 is a DC power source capable of delivering about 20 V.

A vacuum pump can be connected to valve 571 to bring the “cold” and “hot” discs into contact and transfer heat energy from the hot disc to the cold disc. For example, when the power source 566 supplies power to the heating element 565, the latter converts the power into thermal energy and transfers this energy to the disk 563, thereby creating a hot disk. A vacuum pump evacuates air from chamber 573 so that the chamber shrinks and disc 562 touches disc 563 (e.g., a cold disc). When the disk 562 touches the disk 563, the thermal energy of the disk 563 is transferred to the disk 562. When the transfer of thermal energy is no longer required, the vacuum pump pumps air into the chamber to separate the disks 562 and 563.

At a temperature of about -10 ° C and in the presence of ice that has grown on the disk 562, and when the heat transfer system 560 is in an upright position, a power of about 10-25 watts applied to the heating element heats the disk 563 to about 20 ° C. When the vacuum pump pumps air out of the chamber 573, as a result of which the disks 562 and 563 touch each other, ice 577 is removed from the disk 562, for example, by gravity. Although air is typically used in chamber 573, alternatively, other heat insulating gases may be used in chamber 573.

Heat transfer anti-icing system analysis

In the following description, various anti-icing systems with heat transfer are analyzed and their operational characteristics are shown. For example, the characteristics of various materials, for example ice, are analyzed at a certain temperature, the heat capacity of which is known (for example, C _l in Fig. 18). In these analyzes, component values illustrate various conditions, for example, environmental conditions and / or heat transfer modes.

42-46 are graphs illustrating one illustrative analysis of a heat transfer anti-icing system. In this example, a heat transfer anti-icing system comprises first and second heat conductors and a heating element having equal heat capacities. The system is characterized by natural convective heat transfer Nu through an air gap in which the heating element heats the first heat conductor so that the second heat conductor is heated to a temperature of about 275.5 K when the two heat conductors are in contact with each other. Such a system can be characterized using Table 42-1 (calculating the Nusselt number for natural convection of air between discs 562, 563 (Fig. 41):

Table 42-1 (MathCad File) v = 1.57 ^. May ¹⁰ L = 0.0125 g = 9.8 β = 1/273 Pr = 0.69 T _t = 273 T _p = 243, 244 .. 273 T _n (T _p ) = 2T _t -T _p +5 Δ (T _p ) = T _n (T _p ) -T _p
(i.e. temperature difference between the heater and the environment)

Ra _L (243) = 1.276 × 10 ⁴ Nu ₁ (T _p ) = 0.0605 Ra _L (T _p ) ^1/3

where T _p - the temperature of the substrate material (disk 562); T _n - temperature of the heating element (disk 563); ν is the kinematic viscosity of air; L is the distance between the discs 562 and 563, g is the acceleration of gravity; β is the coefficient of thermal expansion of air; Pr is the Prandtl number for air; T _t - the temperature of the melting ice; T _p - the increasing temperature of the disk 562; Δ is the temperature difference; Ra is the Rayleigh number for air; Nu ₁ and Nu ₂ are Nusselt numbers.

Accordingly, FIG. 42 shows (diagram 580) the dependence of the Nusselt number on external temperature (cold disk 562). Table 42-2 allows you to calculate the rate of natural convective heat transfer between discs 562, 563:

Table 42-2 (MathCad File) λ = 0.025

where λ _in - coefficient of thermal conductivity of air; W _to / 2 - the average heat transfer rate when the heater heats the disk 563 from T _p to T _n In Fig. 42, the Nu convection is plotted along the Y-axis 581, and the temperature T _{p of the} substrate material is plotted along the X-axis 582. The average heat loss W _k through the air gap is shown in FIG. 43 (diagram 590). In FIG. 43, the convective heat transfer W _k / 2 is plotted along the Y axis 591, and the temperature T _{p of the} substrate material is plotted along the X axis 592.

около 0,025 м и коэффициент теплопроводности λ_в около 0,026. Перенос тепла W_из можно вычислить согласно Таблице 42-3 (потери тепла через задний изолирующий слой):On Fig shows the transfer of heat W _from through the rear insulation (for example, insulation on the rear side of the first heat conductor, diagram 600). In this embodiment, the insulation is a rigid polyurethane foam having a thickness

about 0.025 m and a thermal conductivity λ _of about 0.026. The heat transfer W _from can be calculated according to Table 42-3 (heat loss through the rear insulating layer):

Table 42-3 (MathCad File) W _from (T _p ) = λ _from ^. Δ (T _p ) / l W _of (243) / 2 = 33.8 W / m ²

Accordingly, the radiative heat transfer W _and through the air gap can be calculated according to Table 42-4 (heat loss through radiation):

Table 42-4 (MathCad File) ε = 0.04 σ = 5.67 ^. 10 ^-8 W _and (T _s ) = ε ^. σ (T _n (T _p ) ⁴ - T _p ⁴ ) W _and (243) = 12.502 W / m ²

where ε is the emissivity of discs 562 and 563; σ is the Stefan-Boltzmann constant. Based on Table 42-4, it is possible to construct a diagram of radiative heat transfer W _and (diagram 600) as a function of temperature T _p in Fig. 44 (T _p and T _{t are} defined above). In Fig. 44, the radiative heat transfer W _{and is} plotted along the Y-axis 601, and the temperature T _{p of the} substrate material is plotted along the X-axis 602.

On Fig shows the total average heat loss W (diagram 610) from the heating element. In Fig. 45, the total average heat loss W is plotted along the Y-axis 611, and the temperature T _{p of the} substrate material is plotted along the X-axis 612. Since the temperature of the heating element periodically varies from T _t to T _n , the average temperature difference between the heating element and the environment is approximately (3/4) · (T _n -T _p ). The total average heat loss W can be calculated according to Table 42-5 (total heat loss to the environment):

Table 42-5 (MathCad File) W (T _p ): = 3/4 ^. ((W _to (T _p ) + W _from (T _p ) + W _and (T _p ))) W (243) = 197.907 W / m ² W (253) = 127.163 W / m ² W (263) = 63.602 W / m ²

On Fig shows the average power W _cf from the power source used in the anti-icing system with heat transfer. In Fig. 46, the average power W _{cf is} plotted on the Y-axis 623, and temperature is plotted on the X-axis 624. The average power results are shown as a function of the three external temperatures of the cold plate T _p (diagrams 620, 621 and 622). The total value of thermal energy Q necessary for heating the heating element from the temperature T _{p of the} substrate material to T _n is calculated in the form of two components Q ₁ and Q ₂ . Q ₁ is the thermal energy due to the heat capacity of the heating element, and Q ₂ is the thermal energy transferred from the heater to the environment (total energy loss from the system). The total thermal energy Q can be calculated according to the following Table 42-6:

Table 42-6 (MathCad File) d = 0.001 t = 1, 2 .. 300 C _p = 900 λ _p = 170 ρ _p = 2700 C _l = 2000 ρ _l = 920 λ _l = 2 Q ₁ (T _p ) = d ^. C _p ^. ρ _p ^. (T _n (T _p ) - T _t ) Q ₁ (243) = 8.505 × 10 ⁴ J / m ²

where d is the thickness of the heating element; t is the duration of heat transfer (for example, a heat pulse); C is the heat capacity of the material; λ is the coefficient of thermal conductivity; ρ is the density of the material (the subscript “l” stands for ice and / or snow, and the subscript “p” stands for the substrate material for most aluminum alloys); T _p - the temperature of the substrate; T _n - temperature of the heating element; and T _t is the temperature of the ice. The average power from the power source used in this anti-icing system with heat transfer (de-icing every three minutes (180 s) can be calculated according to Table 42-7:

Table 42-7 (MathCad File) W _cf (t, T _p ) = Q ₁ (T _p ) / t + W (T _p ) W _cf (180.243) = 670.407 W / m ² (diagram 620) W _cf (180.253) = 464.663 W / m ² (diagram 621) W _cf (180.263) = 266.102 W / m ² (diagram 622).

An anti-icing system with the above characteristics is useful as an anti-icing aerodynamic surface (for example, an airplane wing). Such an anti-icing system can be made of an aluminum alloy 1 mm thick and installed behind the front edge of a small aerodynamic surface, i.e. front open part of the wing of the aircraft. In this example, the aerodynamic system has a span of about 20 cm and a thickness of about 5 cm; de-icer dimensions are 20 cm x 10 cm. At an air speed of about 142 km / h and approximately -10 ° C. Drops of water with a diameter of about 20 microns on the aerodynamic surface forms atmospheric ice. When ice grows to about 5-10 mm, a computer system (for example, controller 78 (FIG. 6) instructs the power source to start anti-icing in order to melt the boundary layer of ice on the aerodynamic surface in order to substantially alter and / or eliminate ice sticking to the aerodynamic surface Then the ice can be removed from the aerodynamic surface by the drag force.This aerodynamic surface cleaning system was built and tested, demonstrating a performance very close to t the theoretical forecasts given in Table 42-7.

Ways to adjust the coefficient of friction

The following embodiments provide for a change in the coefficient of friction between the surface of an object (for example, part of a moving body) and ice or snow. A system similar to system 40 (FIG. 4) uses the equations of FIG. 1 to influence the coefficient of friction between a sliding body and snow (for example, as described for FIGS. 47 and 48). This system allows you to increase or decrease the adhesion between the interface and the snow, which is determined by the specific application. For example, in some sliding bodies described herein, such a system is used as an impulse brake to brake a sliding body as it moves through the snow.

In FIG. 47 and 48 show the characteristics of a sliding body, such as a ski or car tire. The sliding body comprises a sliding body substrate 632 and a heating element 633. The heating element 633 is connected to the sliding body substrate 632 and can directly contact ice and / or snow 630. The heating element 633 is capable of receiving power from a power source, for example, in accordance with the equations for figure 1.

On Fig shows the temperature distribution in the substrate 632 of the sliding body and ice 630 when applying power to the heating element 633 in the form of a pulse. For example, FIG. 48 shows the distance of heat dissipation along the X axis 636 over time t through ice 630 and the substrate 632 as a function of temperature T along the T axis 639 at the ice-object interface. Curve t ₁ expresses the temperature change due to heat dissipation in ice 630 and in the substrate 632 at a given pulse duration. It is shown that the peak t _{1 of the} curve corresponds to a certain temperature 638 on the T 639 axis. The temperature 638 is sufficient to melt the boundary layer of ice 630. The filled region (m) under the curve t ₁ represents the melted boundary layer.

Before the power is supplied to the heating element 633, the ambient temperature is represented by point 637. When a power pulse is applied to the heating element 633, the temperature of the element 633 begins to rise and passes into ice 630 at a distance of 631 (the distance of the boundary layer of ice 630) and to the substrate 632. This temperature increases to point 635, where the ice begins to melt, and continues to grow over the duration of the power pulse. Thermal energy melts a thin boundary layer (m) of ice 630. After turning off the power from the heating element 633, the temperature begins to fall below the melting point 635, curve t ₂ . As the temperature of the heating element decreases, the adhesion of ice 630 to the sliding body substrate 632 changes due to repeated freezing. Repeated freezing increases the adhesion of ice 630 to the substrate 632 and inhibits the sliding body at the interface of the heating element 633.

According to this embodiment, the characteristics of the sliding body satisfy the equations of FIG. 10. For example, the time t of scattering by a length L in the direction of the X axis 636 can be expressed as follows:

(Ур. 11-1)t = L ² / D, where

(Lv. 11-1)

D is the coefficient of thermal conductivity, expressed as

(Ур. 11-2)D = λ / ρc,

(Lv. 11-2)

where λ is the coefficient of thermal conductivity; ρ is the density of the material; C is the heat capacity of the material. Accordingly, equations 11-1 and 11-2 show that the thermal energy absorbed by the ice 630 and the substrate 632 is scattered by a distance proportional to the square root of time t. The shorter the duration of power supply to the heating element 633, the thinner the boundary layer of ice exposed. The time t and the energy Q supplied to the heating element 633 for heating the boundary layer of ice 630 from the external temperature T to the melting point T _t (melting point 638) satisfy the equations considered for FIG.

On Fig shows one sliding body 640 to illustrate changes in friction at the ice-object interface. The sliding body 640 comprises an acrylic slider 644, a force sensor 642 and a heating element 646, for example a titanium foil with a thickness of 12.5 μm to 25 μm. The sliding body 640 uses a heating element 646, which melts the boundary layer of ice 641 adjacent to the sliding body 640 by supplying thermal energy pulses to the layer, for example, according to the equations for FIG. 1. Power can be supplied to the heating element 646 to terminals 645 and 647, as a result of which the heating element 646 melts the boundary layer of ice 641. After melting the boundary layer of ice 641, it is allowed to re-freeze due to lower external temperature, which provides a connection between the ice 641 and the slider 644.

The force sensor 642 obtains information about the force exerted by the slider 644 on the ice 641. The force sensor 642 can transmit this information to the controller 643 to determine how to supply power to the heating element 646. A power supply similar to that described above can supply power to the heating element 646 to melt the boundary layer of ice 641. The melting of the boundary layer of ice 641 leads to a change in the adhesion strength of ice 641 to the sliding body 640 and a change in the coefficient of friction between the ice 641 and the slider 644.

In FIG. 50 and 51 show the use of the sliding body 650 as a ski 654. The sliding body 650 contains metal heating elements 652, for example titanium foil, bonded to the ski surface 651 that is in contact with snow 653. The heating elements 652 are capable of melting a layer of boundary snow interacting with the surface 651, by supplying energy pulses to the snow layer 653, for example, according to the equations for FIG. 1. Power is supplied to the heating elements 652 by one of several devices described herein. After the boundary layer of snow 653 is melted, it re-freezes due to lower external temperature and provides a connection between snow 653 and surface 651. The connection provides increased adhesion to snow 653 by changing the coefficient of friction between ice and sliding body 650.

The sliding body 650 may also include a mount 658, shown in Fig. 51. A switch 660 is placed on the mount 658 to control the power supply to the heating elements 652. A mechanical switch can be used as the switch 660. The switch 660 may also include a manual switch, a ski movement switch, a pressure responsive switch, an accelerometer, a remote control switch and / or a motion sensor. Each switch can be used in sliding body 650 to activate heating and re-freezing the boundary layer of ice to provide the desired coefficient of friction.

In particular, FIG. 50 further shows how the heating elements 652 can be attached to the ski 654. Referring to FIG. 51, the ski boot 656 is inserted into the mount 658. The ski boot 656, if desired, can be used to control the switch 660 to provide power to heating elements 652. Power may be supplied from power sources. When the boot 656 switches the switch 660, the latter transfers power from the power source to the heating elements 652 to melt the boundary layer of snow 653 and, thus, to change the coefficient of friction between the ski 654 and snow 653.

On Fig shows a sliding body in the form of a snowboard 674. The sliding body 670 contains heating elements 672 attached to the bottom surface 675 of the snowboard 674. The surface 675 is in contact with snow during operation of the snowboard 674. The performance of the sliding body 670 may be the same as ski 654 (Fig. 50 and 51). Heating elements 672 may also be integrated in the snowboard 674, but be in thermal communication with the surface 675 according to one embodiment.

On Fig shows a sliding body 680 in the form of a boot 684. The sliding body 680 contains metal heating elements 682, for example titanium foil attached to the heel 688 and the sole 686, the heel 688 and the sole 686 are in contact with snow or ice when a person walks in the snow or ice. The heating elements 682 can also be integrated into the boot 684 (or the heel 686), provided that they are in thermal connection with the outer surface of the heel 688. The heating elements 682 can be made in the form of a thin conductive film (for example, TiN film, film of Cr) deposited either on a polymer substrate (e.g., kapton, ABS) or on a ceramic substrate (e.g., glass ceramic, zirconia ceramic). Energy is supplied to the heating elements 682, as a result of which the heating elements 682 melt the boundary layer of ice adjacent to the heel and / or sole 688, 686. After the boundary layer of ice or snow is melted, it is allowed to re-freeze under the influence of external temperature, which provides ice bonding or snow with a heel and / or sole 688, 686. Power is supplied, as described for figure 1. A small 683 battery (for example, a D-cell battery) is used as a power source. The switch 48 (Fig. 4) connects the power from the power source to the heating elements 682. When the user switches the switch, the latter transfers the power from the battery 683 to the heating elements 682 to melt the boundary layer of ice or snow and change the coefficient of friction between the boot 684 and ice or snow , which improves the grip of the 684 boot.

On Fig shows the sliding body 690 in the form of a bus 692. The sliding body 690 contains metal heating elements 694 embedded in the bus 692. Power is supplied to the heating elements 694, as a result of which the heating elements 694 melt the boundary layer of ice or snow 693. After melting the boundary layer of ice, it is repeatedly frozen under the influence of external temperature and provides a connection between the ice / snow 693 and the tire 692. Power can be supplied to the heating elements 694 in one of several of these ways. The sliding body 690 uses, for example, a car battery as a power source.

In another example, the heating elements 694 include thin metal wires capable of receiving power and converting this power into thermal energy to melt the boundary layer of ice / snow 693 in contact with the bus 692. In addition, the sliding body 690 may include a controller 78 (FIG. 6) to control the power supply (figure 1). According to an embodiment, the user activates the switch, which allows power to be supplied to the heating elements 694 when necessary to provide additional adhesion of the tire 692 to the road surface covered with ice and snow 693. When the user switches the switch by pressing a special button on the car control panel, the switch conducts power from the power source to the heating elements 694 to melt the boundary layer of ice and snow 693 and, thus, to change the coefficient friction between the tire 692 and the ice and snow breaking the road surface when the boundary layer is re-frozen and increases the adhesion of the tire 692 on snow / ice 693.

Thus, the heating elements 694 can act as “impulse brakes”, giving a heating pulse to the interface between the tire 692 and the snow / ice 693. For example, when braking is necessary, the boundary layer of ice is melted. When the pulse stops, the melted spots on the bus 692 are usually re-frozen in a few milliseconds under the influence of external temperature, providing strong connections between the bus 692 and the ice / snow 693. These bonds slow down the movement of the bus 692 relative to the ice / snow 693. For faster cooling of the melted The boundary layer of ice uses the Peltier element 695.

An example of a Peltier element 695 is a thermoelectric module, consisting of an array of granules of a semiconductor doped with bismuth telluride, which has one type of charge carrier (for example, positive or negative) for transferring the main current. Pairs of granules with positive and negative main charge carriers have such a configuration that they are electrically connected in series, but thermally connected in parallel. Metallized ceramic substrates can provide a platform for granules. Thermoelectric modules can function independently or in groups with serial, parallel or series-parallel connections.

When a DC voltage is applied to the Peltier element 695, positive and negative charge carriers in the granule array absorb thermal energy from one surface of the substrate and release it on the opposite surface of the substrate. The substrate on which thermal energy is absorbed can lower the temperature without the use of moving parts, compressors or gases. The opposite substrate, on which thermal energy is released, is heated as a result.

55 is a configuration of a sliding body 700 illustrating how a sliding body affects friction with adjacent snow or ice. The sliding body 700 comprises a plurality of metal heating elements embedded in an area 704 illustrating the electrical conductive rubber of the tire. Power is supplied to the heating elements 712 to melt the boundary layer of ice 714. After melting the boundary layer of ice, it is repeatedly frozen under the influence of external temperature and provides a connection between the ice 714 and the sliding object 700.

The heating element 712 is a thin metal wire capable of receiving power and converting this power into thermal energy to melt the boundary layer of ice 714 in contact with the sliding body 700. A thin electrical insulator 706 near the heating element surrounds the heating element 712. When the heating element receives power from a power source 702, heating elements 712 convert power into heat energy through resistivity. Thermal energy is transferred (thermal radiation lines 710) to ice 714 and a heated region 708, in which the boundary layer of ice 714 is melted. The melted boundary ice changes the coefficient of friction between the sliding body 700 and ice 714, as a result of which the adhesion between the sliding body 700 and ice 714 increases. The friction coefficient changes due to melting and re-freezing when electric power is supplied and disconnected from the heating element 712. For example, an electric power pulse having a duration in accordance with Eq. 1.4 for FIG. 1, melts the boundary layer of ice 714 because it is converted into thermal energy by the heating element 712. When the electric power pulse drops, region 708 is allowed to re-freeze under the influence of lower external temperature and un-melted ice 714. Thus, melting and re-freezing ice 714 changes the coefficient of friction and improves traction and braking when, for example, the sliding body 700 is an object such as a tire or ski.

On Fig shows a sliding body in the form of a caterpillar 724, for example, used for a snowmobile. The sliding body 720 contains heating elements 722 embedded in the caterpillar 724. Power is supplied to the heating elements 722, whereby the heating elements 722 melt the boundary layer of ice adjacent to the track 724. When the boundary layer of ice is melted and the power is no longer supplied, the melted boundary layer water re-freezes due to external temperature and provides the connection of ice with the caterpillar 724. The sliding body 720 uses, for example, a battery as a power source. Illustratively, the caterpillar 724 is shown around the caterpillar wheels 725. The heating elements 722 can be in the form of thin metal wires or in the form of a thin metal foil that converts power to thermal energy to melt the boundary layer of ice in contact with the caterpillar 724. The user, if desired , can activate a switch to supply power to the heating elements 722, for example, when the user determines the need for additional grip between the track 724 and the ground covered with ice and snow m When the user switches the switch, the switch transfers power from a power source (eg, a snowmobile battery) to the heating elements 722 to melt the ice / snow boundary layer to change the friction coefficient between the track 724 and the snow, increasing the adhesion of the track 724 to snow as a result of subsequent re-freezing .

On Fig shows one sliding body 780 in the form of a ski 782; the ski 782 is shown in more detail in view 781. The sliding body 780 comprises a heating element 784 and may have performance characteristics as the ski 654 (Figs. 50 and 51). The heating element 784 can be made, for example, of titanium foil or abrasion resistant conductive paints (for example, nickel or silver based paints), or in the form of a sprayed TiN layer. A heating element 784 is attached to the surface of the ski 782 (installed to provide thermal contact with the surface) to continuously contact the snow and to melt the boundary snow or ice, as described for figure 1.

Figure 781 illustrates a method for attaching a heating element 784 to a ski 782. For example, a heating element 784 is attached to a ski 782 via racks 783. The racks 783 are usually made in the form of a metal conductor serving as terminals of the busbar, and also to protect the heating element 784 from damage. Racks 783 can be used to transfer power from the power source to the heating element 784 to melt the boundary layer of snow and, thus, change the coefficient of friction between the ski 782 and snow.

The heating element 784 contains, for example, a protective coating 785 that protects against damage by stones. Heating element 784, racks 783, and substrate 786 may be interchangeable. When the heating element 784 contains a conductive layer of paint, scratches can be repaired with paints for minor repairs.

On Fig shows a sliding body 800 in the form of a bus 802 according to a variant implementation. The sliding body 800 comprises a heating unit 806 and an optional exhaust subsystem 804. The air exhaust subsystem 804 may comprise cold air exhaust from an automobile air conditioner. The heating unit 806 may include a heating lamp or other heating device for heating the area 805 of the tire 802 by pulsed or continuous thermal energy. The sliding body 800 may use a car battery as a power source.

According to an embodiment, the heating unit element 806 comprises and uses the outlet of an air conditioner or a car engine. In another embodiment, the heating unit 806 contains or uses a water atomizer that creates tiny droplets of water. Water droplets cover the car tire with a thin water film that freezes when in contact with ice, thereby providing strong bonds between the tire and ice.

According to another embodiment, the heating unit 806 comprises a hot cylinder in contact with the tire and can rotate with the tire. The hot rotating cylinder may be heated by the vehicle’s power system, automobile air conditioning and / or vehicle exhaust.

In a working example, the heating unit 806 is capable of receiving power and converting this power into thermal energy to melt the boundary layer of ice 810 in the contact area 807 of the bus 802. When the heating unit 806 receives energy from a power source, it converts it into thermal energy and forms heated region 805. Due to the short duration of exposure to heat, usually only a thin layer of tire rubber is heated. As the tire 802 rotates, the heated region 805 melts the boundary layer of ice 810 in the region 807. As the tire continues to rotate, the melted ice layer re-freezes in the region 808 and changes the friction coefficient between the tire 802 and the ice 810 in the region 809, thereby creating a connection between the tire 802 and ice 810, which leads to an increase in traction between tire 802 and ice 810.

Since the tire 802 has a significant area of contact with ice 810, the rubber of the tire 802 is usually re-cooled before it is heated again by the heating unit 806. Thus, additional cooling is usually not necessary when the outside temperature is below the melting point of the ice. However, additional cooling can be used, for example cold air from an automobile air conditioner can be used to cool a tire through exhaust subsystem 804.

Since the heating unit 806 can provide pulsed thermal energy, the friction coefficient can be discretely changed by melting and re-freezing the boundary ice 810 when applying and turning off electrical power (for example, the tire 802 is constantly heated and cooled during rotation. According to an embodiment, the heating unit 806 can contain a heated metal brush pressed against the rotating tire 802. Heat flow from the brush to the surface 801 of the tire 802 heats a thin layer of tire rubber, causing subsequent melting of boundary ice.

The average power used by the heating unit 806, usually depends on the external temperature and speed of the car, but can be in the range from 10 watts to 100 watts. In some extreme cases, it can range from 1 watt to 1000 watt. In addition, depending on the temperature and speed conditions, the period during which the tire rubber 802 is heated by the heating unit 806 is in the range from 3 ms to 100 ms, but, in more extreme cases, it can be from 1 ms to 1 s. The re-freezing time can be approximately the same as for a pulse anti-icing system, for example, for figures 1-6 (usually in the range from 1 ms to 100 ms). This time can be adjusted to provide maximum grip when most of the tire-to-road contact area is re-frozen.

On Fig shows the configuration of one sliding body 820. The sliding body 820 contains the boundary 825 of the sliding body and the lamp 826 flash. The flash lamp 826 is capable of illuminating the interface of the moving body 825 with a light pulse (e.g., a flash of light). The flash lamp 826 receives power from a power source 822 to melt the boundary layer of ice 821. The flash lamp 826 delivers light pulses to a thin blackened layer 827 of boundary ice 821. Typical duration and energy for a single pulse of lamp 826 is from 1 ms to 10 ms, generating energy approximately 1 J to 100 J.

According to an embodiment, a single flash from the flash lamp 826 melts the boundary layer of ice 821 when the flash lamp 826 irradiates the moving body interface 825. The sliding body interface 825 is transparent and converts the flash energy into thermal energy when light falls on the blackened layer 827. For example, light from a lamp 826 (eg, visible light or infrared light) is absorbed by the layer 827 and converted into thermal energy. Then, the converted thermal energy is absorbed in the boundary layer of ice 821 adjacent to the sliding body 820. When energy is absorbed by the boundary layer 821, the layer is melted. Then the layer is re-frozen under the influence of external temperature to provide a connection between the sliding body 824 and ice 821.

Analysis of changes in the coefficient of friction

Below are analyzes in which the friction coefficient changes at the ice-object interface or at the snow-object interface. These analyzes can experimentally and graphically illustrate the change in the coefficient of friction.

In FIG. 60 is a diagram 830 illustrating the relationship between the friction coefficients of certain sliding bodies and the voltage applied to heating elements attached to the sliding bodies. To charge the capacitor 2.35 uF used an electrical circuit (figure 2). Then the capacitor was discharged through the heating element. In Fig. 60, the friction force is plotted along the Y axis, and stress is plotted along the X axis. Diagram 830 makes it possible to distinguish two similar sliding bodies, each of which has a heating element (one heating element contains titanium foil about 12.5 microns thick and the other heating element contains titanium foil about 25 microns thick). When about 50 V of power is supplied to the heating elements, the coefficient of friction between the sliding bodies and the snow changes, as shown. At a voltage of about 100 V, the friction coefficients of sliding bodies in the snow begin to differ from each other. Accordingly, the thickness of the material of the heating element is essentially independent of voltage up to about 100 V, which may affect design decisions.

61 is a diagram 840 illustrating the relationship between the resting friction force of some sliding bodies and the normal pressure exerted by the sliding body on snow. On Fig on the axis Y 841 the rest friction force is plotted, and on the axis X 842 normal pressure is plotted. Diagram 840 makes it possible to distinguish between two similar sliding bodies, each of which has a heating element (one heating element contains titanium foil about 12.5 microns thick and the other heating element contains titanium foil about 25 microns thick). The two diagrams below show the resting friction force for the same sliding bodies without supplying heating pulses. Other experimental data, such as DC voltage (90 V), temperature (-11 ° C), and the capacitor used in the circuit of FIG. 2, are shown in the inset.

62 is a diagram 850 illustrating the relationship between the friction coefficients of some sliding bodies and the voltage applied to the connected heating element according to an embodiment. In Fig. 62, the friction force is plotted along the Y-axis 853, and stress is plotted along the X-axis 852. Chart 850 allows you to distinguish between two similar sliding bodies, each of which has a heating element (one heating element contains titanium foil about 12.5 microns thick and the other heating element contains titanium foil about 25 microns thick). Each sliding body has an average curve defined by a range of friction coefficients associated with a particular applied stress. For example, a sliding body with a heating element in the form of a titanium foil with a thickness of 25 μm has a friction coefficient that varies from 4.9 N to 6 N (point 851). In FIG. 62 it is shown that the pulse brake works well even when the external temperature is very close to the melting point (-2 ° C), good braking force is achieved even at -0.5 ° C.

63 is a diagram 860 illustrating the relationship between the friction coefficients of one sliding body and the sliding time at a constant speed of 3.5 mm / s. 63, friction force is plotted on the Y-axis 863, and time is plotted on the X-axis 864. According to an embodiment, four short pulses of heating power were applied, during which the sliding body moved at a speed of about 3.5 m / s. The 1.36 uF capacitor was discharged to the heating element at a voltage of about 110 V in four 861 pulses. The duration of the heating pulses was about 2.5 ms. A heating element connected to a sliding body received power from a power source for a limited time (power pulse), for example, according to the equations for FIG. 1. A heating element converted this power into thermal energy and supplied thermal energy to the interface between the surface and ice. The heating element melted the boundary layer of snow or ice adjacent to a moving object. The melting of the boundary layer changes the adhesion of snow on the surface of the sliding body and changes the coefficient of friction between the sliding body and snow or ice. During each pulse 861, the friction coefficient changes. The change in the coefficient of friction between the sliding body and snow leads to the fact that the sliding body resists sliding, i.e. friction increases. This is shown in FIG. 63 as sharp peaks of friction. By changing the energy of the pulse and the intervals between pulses, it is possible to achieve the desired value of the friction force. It will be understood by those skilled in the art that such an adjustable brake can be linked to a speed measurement system to provide the ski with a cruise control system: the skier can set the desired maximum speed for himself and his children to ensure the safety of the ski trip.

64 is a diagram 870 illustrating another relationship between the friction coefficients of one sliding body and the voltage applied to the connected heating element according to an embodiment. In Fig. 64, the friction force is plotted along the Y-axis 871, and stress is plotted along the X-axis 872. The voltage was varied to determine the friction coefficients as a function of power. When applying power with a voltage of 50 V to the heating elements, the friction coefficient changed. At about 90 V, the coefficient of friction of the sliding body relative to snow reaches saturation, after which it remains almost constant up to about 110 V. Accordingly, a voltage from 90 V to 110 V can provide an increase in the coefficient of friction, which is practically independent of the voltage between 90 V and 110 V This information is useful when choosing a power source for a moving body.

In FIG. 65 and 66 are diagrams illustrating thermal energy Q and cooling time t _OHL sliding body. On Fig on the Y-axis 881 delayed heat dissipation in the snow L _p , and on the X-axis 882 time is delayed. On Fig on the axis Y 891 plotted thermal energy, and on the axis X 892 plotted the resistance of the heater. During the first 10 milliseconds of heating, heat penetrates into the snow only to a depth of thirty-six microns. Such a thin layer of snow has a low heat capacity, therefore, low energy is required to heat it to its melting point (i.e. 273K). Table 65-1 below allows you to calculate the total energy Q (Δ, R) used to melt a ten-micron layer of ice and to heat the boundary material of snow and ice at Δ ° C. When the heating power is independent of T, the result is shown in Table 65-1:

Table 65-1 W = 10 ⁴ , 2 ^. 10 ⁴ .. 10 ⁶ λ _ski = 0.2 ρ _ski = 1000 C _ski = 1.54 ^. 10 ³ ρ _snow = 300 C _snow = 2.2 ^. 10 ³ λ _snow = 0.2 D _snow = λ _snow / (ρ _snow ^. C _snow ) s R = 0.1, 0.2 .. 10 Ohm C = 10 ^-4 , 2 ^. 10 ^-4 .. 2 ^. 10 ^-2 f t (R, C) = R . C D _ski = λ _ski / (ρ _ski ^. C _ski ) Δ = 0.01, 0.02 .. 10 T = 0, 10 ^-4 .. 10 ^-1

According to FIG. 65 and 66, the heat dissipation length L _p (i.e., diagram 880, FIG. 65) is expressed as follows:

L _p (10 ^-2 ) = 5,505 × 10 ^-5 L _p (1) = 5.505 × 10 ^-4 L _p (0,1) = 1,741 × 10 ^-4 L _p (0.01) = 5.505 × 10 ^-5 V = 100 S = 0.0025 W (R) = V ² / 2RS d _load = 1.25 ^. 10 ^-5 C _load = 523 ρ _load = 4.5 ^. 10 ³ l _melt = 1 ^. 10 ^-5 q _melt = 3.33 ^. May ¹⁰

C (20, 2.5) = 8.464 × 10 ^-4 Δ = 20 d ^{_heating. S.} ρ ^_heating. Δ ^. C _load = 1,471 l _melt ^. ρ _snow ^{. S.} q _melt = 2,498

where S is the area of the heater; T _t - melting temperature; T is the external temperature; λ is the coefficient of thermal conductivity; ρ is the density of the material; C is the heat capacity of the material (the subscript “ice” refers to ice and / or snow, the subscript “skis” refers to the substrate material, for example, ski or snowboard, the subscript “heat” refers to a heating element); Q - thermal energy; D is the coefficient of thermal diffusivity; Δ is the change in temperature; t is the time; V is the voltage; d is the thickness; R is the resistance; W is the power per square meter; l _melt - the thickness of the melted layer; and q is the latent heat of fusion. For very short pulses, almost all of the thermal energy Q is used to melt a thin layer of snow (diagram 890, Fig. 66); the heat capacity of snow and ski makes a small contribution to Q. The calculation of the re-freezing time is shown in Table 65-2:

Table 65-2 λ _ski = 0.5 λ _snow = 0.5

t _cool (20.1) = 0.013 "s"

Table 65-3 illustrates typical capacities of conventional batteries used as power sources in a pulse brake device. For example, a pair of small AA batteries can be used in a pulse brake device for skiing for about one hour.

Table 65-3 Battery size Type of Voltage ^A. h ^Tues. h one AA, Duracell
Couple normal 1,5 2.85 4,275 3 5.7 8.55 2 C, Duracell couple normal 1,5 7.8 11.7 3 15.6 23,4 3 D, Duracell couple normal 1,5 fifteen 22.5 3 thirty 45 four D, Varta
Couple normal 1,5 16.5 24.75 3 33 49.5 5 9v, Duracell
couple
4 pieces normal 9 0.58 5.22 eighteen 1.16 10.44 36 20.88 - no converter needed-- 6 Type D
TL2300 / SD, Li
Couple Li-ion recharge. 3.6 16.5 59,4 7.2 33 ($ 20.65) 118.4 ($ 41.30) 7 DD
TL5137 / TDD, Li Li-ion recharge. 3.6 35 126 ($ 48.93) 8 AA
TL5104 / PT2 AA, Li Li-ion recharge. 3.6 2.1 7.56 9 C
TL2200 / SC, Li, 7200 mA ^. h
Couple Li-ion recharge. 3.6 7.2 25.92 7.2 14,4 ($ 16.73) 52

67 is an analysis of a sliding body 900 illustrating friction enhancements for an embodiment in which the sliding body is a tire 902 with different thermal zones. According to this analysis, φ ₀ is the heating zone; φ ₁ - air cooling zone; φ ₂ - melting zone; φ ₃ - zone of repeated freezing; φ ₄ is the binding zone; ω ₀ is the angular velocity of the tire; υ ₀ is the linear speed of the car; R is the radius of the tire 902; and A is the tire width 902. Assuming that the heating zone φ _{0 is} uniformly heated by the total power w ′, we obtain the following expression for the power density per square meter:

. (Ур. 67-1)

. (Lv. 67-1)

Each point of the heating zone φ ₀ can be “surface heated” in time t, expressed as

. (Ур. 67-2)

. (Lv. 67-2)

и зона нагрева φ₀ получает плотность энергииFor example, when υ ₀ = 30 m / s (108 km / h) and φ ₀ R = 0.1 m,

and the heating zone φ ₀ receives the energy density

(Ур.67-3)

(Lv. 67-3)

Estimating the minimum Q and assuming a thickness of melted ice equal to 10 μm, we obtain

Q = d · q · ρ _l , (Lv. 67-4)

where d is the thickness of the melted layer in the zone φ ₂ , ρ is the density of ice, q is the latent heat of fusion. Respectively,

и, следовательно, (Ур. 67-5)

and therefore (Lv. 67-5)

w '= ^A. υ ₀ ^. d ^. q ^. ρ _l (Lv. 67-6)

Now we estimate the re-freezing zone, which increases the coefficient of friction to μ = 0.5. For example, at normal pressure 2 ^. 10 ⁵ Pa, the friction force per square meter corresponding to μ = 0.5 is 10 ⁵ Pa. For the ice / rubber interface, shear adhesion strength is about 1 MPa. Thus, re-freezing may require only about 10% of the ice / tire contact area (i.e., re-freezing zone φ ₃ ) to provide μ = 0.5. When the melted ice layer has a thickness of about 3.3 μm, the energy consumption is about 500 watts for a speed v ₀ of about 108 km / h. For a speed v _{0 of} about 7.2 km / h with the same thickness, energy consumption is only about 33 watts.

. Это время доступно для действий растапливания и повторного замораживания и достаточно велико для осуществления этих действий.At a speed of v ₀ 20 km / h, each point on the tire surface can be in contact with ice for about

. This time is available for melting and re-freezing and is large enough to carry out these actions.

In FIG. 68 and 69 show experimental results in which ice friction is reduced either by applying RF power (FIG. 68) or by supplying low-energy heating pulses (FIG. 69). 68, friction force is plotted on the Y-axis, and time, in seconds, is plotted on the X-axis. For example, FIG. 68 shows the friction force (H) versus time for a sliding body when moving on ice with an external temperature T of about -5 ° C, a normal pressure of P of about 42 kPa and a sliding speed of about 1 cm / s. In this embodiment, the friction modifying system comprises a comb circuit attached to the base of the sliding body, which is adjacent to the ice. The comb circuit also contains copper electrodes having an interelectrode distance of about 75 microns. The power source delivers alternating current voltage of about 30 V RMS to the RF electrodes with a frequency of about 20 kHz. The electrodes generate heat in ice with a density of about 100 W / m ² . When a sliding body moves at a speed of about 1 cm / s and power is supplied to the electrodes, the friction force decreases by about 40%. For example, a power source delivers power to the RF electrodes at time 910 (near a time t equal to 10 s). Electrodes convert power to thermal energy, which dissipates towards ice. The sliding body begins to slide at time 912, i.e. at about time t equal to 13 s. In this embodiment, the RF power is turned off at time 911 (i.e., approximately at time t equal to 28 s). Without applying RF power, the friction on ice increases from 4 N to 7 N. The latter is the background friction force on ice in the absence of power supply to the moving body, which stops at time 913 (i.e., near time t equal to 33 s )

According to this embodiment, the continuous supply of RF power increases the temperature of the ice, thereby reducing the friction force without melting the ice, and thus changes the coefficient of friction.

On Fig shows the friction force (N) as a function of time for a sliding body moving in snow at an external temperature T of about -10 ° C, a normal pressure P of about 215 kPa and a sliding speed v of about 3 mm / s. In Fig. 69, the friction force is plotted on the Y-axis 925, and the time in seconds is plotted on the X-axis 926. According to this embodiment, the friction modifying system comprises a titanium foil heater. Short pulses of heating the DC power are supplied to the heater at time points 922 and 923, causing a decrease in friction against snow, in contrast to the braking effect described in the same system above. The main difference of this embodiment is pulse braking. As shown in FIG. 69, the amount of heating energy is insufficient to melt the snow. In the absence of a melted layer, re-freezing does not occur, therefore there is no braking. However, as the heater heats the snow, friction is reduced. In the experiment shown in FIG. 69, the snow surface is heated by pulses from -10 ° C to about -1 ° C. The sliding body experiences a rapid increase in resting friction between the ice and the moving body at time 921 (for example, near time t equal to 31 s). The power source gives a power pulse to the electrodes at time points 922 and 923 (time t equal to 38 s and 42 s, respectively). In this embodiment, the sliding body stops at time 924, when time t is 50 s.

According to some embodiments, the electrodes of the comb circuit are made of solid conductive materials, for example titanium nitride, zirconium oxide doped with other oxides (for example, yttrium oxide), as well as TiN coated titanium and stainless steel foil, to increase the abrasion resistance of the circuit. Other embodiments may include protecting the electrodes with coatings of protective films, such as alumina.

The above description should be considered as illustrative and not limiting.

Claims (90)

1. The method of thermal change of the interface between the ice and the object, which consists in supplying heating energy to the interface to melt the boundary layer of ice, limit the duration of the supply of heating energy to the interface, as a result of which the heating energy has a heat dissipation distance in ice, which does not exceed the thickness of the boundary layer of ice. 2. The method according to claim 1, characterized in that the step of supplying heating energy comprises a step at which power is supplied to the interface, the value of which is at least inversely proportional to the amount of energy used to melt the boundary layer of ice. 3. The method according to claim 2, characterized in that the duration limiting step comprises the step of limiting the duration of the power supplying step to the interface, as a result of which the duration is at least inversely proportional to the square of the power value. 4. The method according to claim 1, characterized in that the step of supplying heating energy comprises a step at which power is supplied to the interface, the value of which is substantially inversely proportional to the amount of energy used to melt the boundary layer of ice, and the step of limiting the duration comprises a step in which the duration of the step of supplying power to the interface is limited, as a result of which the duration is substantially inversely proportional to the square of the power value. 5. The method according to claim 1, characterized in that it further comprises the step of facilitating the repeated freezing of the boundary layer of ice in order to influence the coefficient of friction between the object and the ice. 6. The method according to claim 5, characterized in that the step of facilitating re-freezing comprises one or more stages, in which (1) expect re-freezing after the stage of limiting the duration, (2) blow the interface with cold air, (3) spray water on interface 7. The method according to claim 1, characterized in that the object is selected from the group consisting of an airplane structure, a windshield, a mirror, a headlight, a power line, a funicular structure, a wind turbine rotor surface, a helicopter rotor surface, a roof, a deck, a building structure , roads, bridge construction, construction of the freezer, antenna, satellite antenna, railway structure, construction of the tunnel, cable, road sign, snowshoe, ski, snowboard, skate and boot. 8. The method according to claim 1, characterized in that the step of supplying heating energy to the interface comprises the step of supplying heating energy to the interface to melt the boundary layer of ice, the thickness of which is less than about five centimeters. 9. The method according to claim 1, characterized in that the step of supplying heating energy to the interface comprises the step of supplying heating energy to the interface to melt the boundary layer of ice, the thickness of which is less than about one millimeter. 10. The method according to claim 1, characterized in that the step of supplying heating energy to the interface comprises the step of supplying heating energy to the interface to melt the boundary layer of ice, the thickness of which is from one micron to one millimeter. 11. The method according to claim 1, characterized in that the step of limiting the duration of the stage of supplying heating energy to the interface contains a stage at which energy is supplied to the interface for a maximum of 100 s. 12. The method according to claim 1, characterized in that the step of supplying heating energy to the interface contains a stage in which power is supplied to the heating element thermally connected to the interface. 13. The method according to p. 12, characterized in that the step of supplying heating energy to the interface contains a stage in which power is supplied to the heating element located inside the object. 14. The method according to p. 12, characterized in that the step of supplying heating energy to the interface contains a stage at which power is supplied to the heating element located on the surface of the object and in contact with the interface. 15. The method according to p. 12, characterized in that the step of supplying heating energy to the interface contains the stage of creating an electrical resistance for the power using the heating element. 16. The method according to p. 12, characterized in that the step of limiting the duration comprises the stage of adjusting the duration of the stage of power supply according to the ratio

where: t is the duration; T _t - the temperature of the melting ice; T is the ambient temperature; λ _l - coefficient of thermal conductivity of ice; ρ _l is the density of the ice material; with _l - specific heat of ice; λ _p - the coefficient of thermal conductivity of one or both of the object and / or heating element; ρ _p - the density of the material of one or both of the object and / or the heating element; c _p is the specific heat of the material of one or both of the object and / or the heating element; W is the power. 17. The method according to p. 12, characterized in that the step of supplying power contains a stage in which the energy is regulated according to the ratio:

where Q is the energy that thermally melts the boundary ice; T _{t is the} temperature needed to melt the boundary ice; T is the ambient temperature; λ _l - coefficient of thermal conductivity of ice; ρ _l is the density of the ice material; with _l - specific heat of ice; λ _p - the coefficient of thermal conductivity of one or both of the object and / or heating element; ρ _p - the density of the material of one or both of the object and / or the heating element; c _p is the specific heat of the material of one or both of the object and / or the heating element; W is the power. 18. The method according to p. 12, characterized in that the step of supplying power comprises the step of regulating the energy according to the ratio

where Q is the energy that thermally melts the boundary ice; T _{t is the} temperature needed to melt the boundary ice; T is the ambient temperature; λ _l - coefficient of thermal conductivity of ice; ρ _l is the density of the ice material; with _l - specific heat of ice; λ _p - the coefficient of thermal conductivity of one or both of the object and / or heating element; ρ _p - the density of the material of one or both of the object and / or the heating element; c _p is the specific heat of the material of one or both of the object and / or the heating element; d _l - the thickness of the boundary layer of ice; ρ _l is the density of ice; q _l - latent heat of melting ice; W is the power; With _heating and ρ _heating - specific heat capacity and density, respectively, of the heating element. 19. The method according to claim 1, characterized in that it further comprises a step in which the feeding and limiting steps are periodically repeated in order to generate the required coefficient of friction between the object and the ice. 20. The method according to claim 1, characterized in that the step of limiting the duration comprises a step in which the duration is limited to a value of from 1 ms to 10 s. 21. The method according to claim 1, characterized in that it further comprises the step of repeatedly supplying power to the interface after re-freezing the boundary layer in order to selectively adjust the coefficient of friction between the ice and the object when the object moves on ice. 22. The method according to claim 1, characterized in that the ice contains snow. 23. The method according to claim 1, characterized in that the object contains a sliding body. 24. The method according to item 23, wherein the sliding body contains one element selected from the group consisting of a boot, snowboard and ski. 25. A method of controlling the coefficient of friction between an object and ice, which consists in the fact that (1) supply pulsed energy to the interface between the object and ice in order to melt the boundary layer of ice at the interface and reduce the coefficient of friction, (2) facilitate the repeated freezing of the boundary ice at the interface to increase the coefficient of friction, (3) repeat steps (1) and (2) to adjust the average coefficient of friction between the object and the ice. 26. The method according A.25, characterized in that the step of facilitating re-freezing comprises the step of moving the object on ice to reduce the temperature of the object. 27. The method according A.25, characterized in that the step of supplying pulsed energy comprises the steps of blowing the object with first air, the first air having a temperature above freezing, and moving the object in contact with ice. 28. The method according to item 27, wherein the object contains a car tire. 29. The method according to item 27, wherein the step of facilitating re-freezing comprises the step of blowing the object with second air, the second air having a temperature lower than the temperature of the first air. 30. A sliding body having a surface intended for contact with snow or ice, containing a power source for generating power, a heating element for converting power to heat on the surface, and heat sufficient to melt the boundary layer of ice at the interface, a controller for controlling the duration heat supply to the heating element to adjust the coefficient of friction between the sliding body and ice or snow by limiting the distribution of heat at the interface. 31. The sliding body according to claim 30, wherein the sliding body has a shape selected from the group consisting of a boot, ski snowboard and snowshoe. 32. The sliding body of claim 30, wherein the power source comprises a battery. 33. The sliding body according to claim 30, wherein the sliding body has a shape selected from the group consisting of ski, skate and snowboard, while the controller responds to user commands, modulating the power supplied to the surface, resulting in a sliding speed The body is controllable. 34. The system of thermal change of the ice-object interface, containing a power source for generating power, a heating element connected to a power source to convert power to heat at the interface, a controller connected to a power source to limit the duration of power supply to the heating element as a result of which only the boundary layer of ice is melted at the interface. 35. The system according to clause 34, wherein the boundary layer has a thickness of less than five centimeters. 36. The system according to clause 34, wherein the boundary layer has a thickness of from one micron to one millimeter. 37. The system according to clause 34, wherein the power source is capable of generating power, the magnitude of which is essentially inversely proportional to the amount of energy needed to melt the boundary ice, while the controller is able to limit the duration, resulting in essentially inversely proportional to the square of the power value. 38. The system according to clause 34, characterized in that it further comprises a sensor connected to the controller, to determine the temperature of the interface and to generate a feedback signal that reports the temperature to the controller. 39. The system according to clause 34, wherein the power source contains at least one element selected from the group consisting of a battery, a capacitor, a flywheel, a high voltage power source. 40. The system according to § 39, wherein the capacitor is selected from the group consisting of at least a supercapacitor, an electrolytic capacitor and an ultracapacitor. 41. The system according to clause 34, wherein the heating element contains a thin film of conductive material that transfers heat from the heating element to the interface to change the coefficient of friction between the object and ice. 42. The system according to clause 34, wherein the heating element comprises a semiconductor material for converting power to heat at the interface to change the coefficient of friction between the object and ice. 43. The system according to clause 34, characterized in that it further comprises a switch connected to the controller, for receiving from the controller a control signal to limit the duration of the power supply to the heating element. 44. The system according to clause 34, wherein the power source, the heating element and the controller are configured with an object that forms an interface between the ice and the object, the object being selected from the group consisting of an airplane, a windshield, a mirror, a headlight, a power line , the construction of the funicular, the rotor of the wind turbine, the rotor of the helicopter, the roof, the deck, the construction of the building, the road, the construction of the bridge, the construction of the freezer, antenna, railway construction, the construction of the tunnel, cable, train, ship, drilling platform, generator and road sign. 45. The method of heating an object to a temperature T, namely, that power W is supplied to the object, the value of which is approximately inversely proportional to the energy sufficient to raise the temperature of the object to a temperature T, the duration of the power supply W is regulated so that it is inversely proportional to W ² . 46. The method of cooling an object to a temperature T, namely, that power W is taken from the object, the value of which is inversely proportional to the energy sufficient to lower the temperature of the object to temperature T, the duration of the power W is adjusted so that it is inversely proportional to W ² . 47. A windshield de-icer comprising a windshield, a substantially transparent heating element placed in conjunction with a windshield that generates heat by supplying power in an amount sufficient to melt the boundary layer of ice on the windshield, a controller for limiting the duration of heat supply, that the depth of heat dissipation into ice is less than the thickness of the boundary layer. 48. The windshield de-icer according to Claim 47, wherein the heating element is selected from a visually transparent semiconductor material having a band gap for electrons above about 3 eV. 49. The windshield de-icer according to claim 48, characterized in that the material contains one of the substances selected from the group consisting of ZnO, ZnS and mixtures thereof. 50. The windshield de-icer according to Claim 47, wherein the heating element is selected from a transparent conductive material. 51. The windshield de-icer according to claim 50, characterized in that the material contains one substance selected from the group consisting of indium tin oxide (ITO), tin oxide, thin metal films and mixtures thereof. 52. The windshield de-icer according to claim 47, further comprising a protective coating on the heating element. 53. The windshield de-icer according to claim 47, characterized in that it further comprises a power source for generating power. 54. The windshield de-icer according to claim 51, wherein the power source comprises a car battery. 55. The windshield de-icer according to claim 53, wherein the thickness is from one micron to one millimeter. 56. The windshield de-icer according to claim 53, wherein the heating element consists of a plurality of heating elements forming a plurality of segmented areas, wherein the controller is capable of supplying power to each of the plurality of heating elements to remove ice from the windshield segments. 57. A method of changing friction between an object and ice / snow, which consists in using a heating element to supply a first pulse of thermal energy to the interface between the object and ice / snow, the first pulse being sufficient to melt the boundary layer of ice / snow adjacent to re-freeze the water forming the boundary layer to form the first bond between the object and ice / snow. 58. The method according to p. 57, characterized in that it further comprises the steps of using the specified heating element to supply a second pulse of thermal energy after the stage of re-freezing to re-melt at least part of the boundary layer, re-frozen re-melted boundary layer to form a second bond between the object and the ice / snow. 59. The method according to clause 57, wherein in the step of using the heating element, a hot cylinder is pressed against an object in the form of a car tire. 60. The method according to p. 59, characterized in that it further uses electric heating of the hot cylinder. 61. The method according to p. 59, characterized in that at the stage of re-freezing press the cold cylinder to the car tire. 62. The method according to clause 57, characterized in that at the stage of re-freezing use automotive air conditioning. 63. The method according to clause 57, characterized in that they use a heating element containing a metal heater, at the stage of use of the heating element, pulsed power is supplied to a metal heater thermally connected to the interface. 64. The method according to clause 57, wherein said heating element is made of a material with low heat capacity. 65. The method according to clause 57, characterized in that it further comprises the step of discharging the capacitor to the heating element. 66. The method according to p, characterized in that it further comprises the step of charging the capacitor from the power source. 67. The method according to p, characterized in that it further use a switch to charge and, accordingly, discharge the capacitor. 68. The method according to clause 57, wherein in the step of using the heating element, a hot plate is attached through one or more holes to the base of the sliding body adjacent to the ice / snow. 69. The method according to clause 57, wherein in the step of using the heating element, an electric pulse power is supplied to the heating element connected to the base of the object in the form of a ski. 70. The method according to p, characterized in that it further comprises activating the action of braking the ski by means of a device selected from the group consisting of a manual switch, a ski movement switch, an accelerometer, a switch, an activated pressure, and a motion sensor. 71. The method according to clause 57, wherein in the step of using the heating element, pulsed electrical energy is supplied to one or more heating elements at the base of the object in the form of a snowboard. 72. The method according to clause 57, wherein the portable battery is additionally used as an energy source during the use of the heating element. 73. The method according to clause 57, characterized in that at the stage of use of the heating element using a pulsed lamp to heat the object. 74. The method according to p, characterized in that the object has the appearance of a rotating tire, the lamp light temporarily heats the corresponding zones of the tire in which the layer is melted, and the rotation of the tire leads to repeated freezing of the layer. 75. The method according to clause 57, characterized in that at the stage of use of the heating element using a metal brush located opposite the object in the form of a car tire. 76. The method according to clause 57, wherein in the step of using the heating element, a flash lamp is used that irradiates the layer through the object. 77. The method according to § 57, characterized in that at the stage of using the heating element, an automobile exhaust is used to heat a hot cylinder. 78. The method according to § 57, characterized in that at the stage of re-freezing using a car air conditioner. 79. The method according to p. 57, characterized in that at the stage of repeated freezing using an electric Peltier element. 80. A method of heating an object to a desired temperature, which consists in storing thermal energy in isolation from the object and in an amount at least sufficient to heat the object to the desired temperature, and regulating the physical and / or thermal properties of the interface between thermal energy and object to transfer at least part of the thermal energy to the object. 81. The method according to p. 80, characterized in that it further comprises the step of transferring energy to the boundary layer of ice in order to break the adhesion of ice to the surface of the object, the desired temperature being 0 ° C or higher. 82. The method according to p. 80, characterized in that at the stage of transfer violate the adhesion of ice to the surface of at least one of the objects selected from the group consisting of an airplane, an airplane wing, a car windshield, a boat, a road, a bridge, sidewalk, freezer, refrigerator, ice maker, ship, train, drilling platform, building, treadmill, window. 83. The method according to p. 80, characterized in that at the stage of adjustment transfer thermal energy from the first surface of the membrane to the second surface of the membrane by deflation (air exhaust) of the membrane. 84. The method according to p. 80, characterized in that at the stage of adjustment periodically apply pulses to the interface for periodic heating of the object. 85. The method according to p. 80, wherein the step of periodically supplying pulses comprises the step of periodically moving the components of the heating element to change the heat transfer rate between the heat storage and the object. 86. The method according to p, characterized in that the components contain a combination of corrugated insulating elements. 87. The method according to p, characterized in that at the stage of accumulation, the liquid and / or gas are heated, at the stage of adjustment, liquid and / or gas are passed near the object, while the thermal energy of the liquid or gas is transferred to the object and the object is heated. Priority on points: 02/11/2002 in accordance with claims 1-4, 6, 7, 8-20, 22-24, 34-48, 50-57; 07/23/2002 according to - pp. 5, 21, 25-29, 30-33, 58-80; 08.21.2002 according to - pp. 49, 81-88.

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