KR100346272B1 - The refrigerating system with bypass and ejector - Google Patents

Abstract

A refrigeration system consisting of an evaporator, a compressor, a condenser, and an expander according to the present invention, comprising: a compressor side pipe capable of bypassing a flow of refrigerant to be discharged to an outlet of a compressor between the compressor and the condenser; A compressor side pipe valve inserted into an inlet of the side pipe to adjust an amount of refrigerant flowing into the side pipe; A pressure reducing device inserted into a side pipe extending from the valve to lower the pressure of the refrigerant; The expander may include an expansion ejector configured to suck together a high-pressure driving fluid discharged from the condenser and a low-pressure suction fluid from the evaporator to discharge at a proper pressure; The evaporator is divided into two strands at the refrigerant outlet, and a pipeline is provided to introduce refrigerant into the compressor and the expansion ejector, respectively, and the amount and pressure of the refrigerant circulated in the entire refrigeration refrigeration cycle are adjusted.

The refrigeration refrigeration system equipped with the side pipe and the ejector according to the present invention is free to adjust the amount of refrigerant circulated in the refrigeration cycle according to the refrigeration load to prevent the cyclic loss (Cyclic Loss) caused by frequent shutdown of the system The work of the compressor can be reduced, and consequently, the efficiency of the system is improved.

Description

Refrigeration refrigeration system with side pipe and ejector {The refrigerating system with bypass and ejector}

The present invention relates to a refrigeration refrigeration system, and more particularly, by using an ejector instead of an expansion valve or a capillary tube used as an expander in a conventional refrigeration refrigeration system consisting of a compressor, a condenser, an expander, and an evaporator according to a flow of a refrigerant. The present invention relates to a refrigerating and freezing system, which is capable of increasing the efficiency of the freezing and refrigerating system and adjusting the amount of the refrigerant flowing through the entire freezing and cooling system according to the freezing load by providing a side pipe.

On the other hand, the refrigeration system is operated by applying a phase change material called a refrigerant (refrigerant), the evaporator, the compressor, the condenser, the expander constituting the refrigerator as a whole, the refrigerant is circulated in the connected system, the refrigerant is In the circulating process, heat is absorbed as the refrigerant undergoes a phase change process, and a process of releasing the heat is continuously performed to obtain a desired temperature at a specific place.

1 is a block diagram of a conventional refrigeration system.

Referring to FIG. 1, a conventional refrigerator is composed of an evaporator 10, a compressor 11, a condenser 12, and an expansion apparatus 13.

The evaporator 10 is installed in a place where a low temperature is to be maintained and is a device in which a low pressure liquid refrigerant absorbs external heat to become a low pressure gas refrigerant.

The compressor 11 is a device that compresses the evaporated low-pressure gas refrigerant into a high-temperature, high-pressure gas refrigerant, and induces the flow of the refrigerant in the refrigeration system as a whole.

The condenser 12 is a device that cools the compressed high-temperature high-pressure gas refrigerant to a low-temperature high-pressure liquid refrigerant.

The inflator 13 is a device that expands the low-temperature, high-pressure liquid refrigerant by using a capillary tube to form a low-pressure liquid refrigerant.

In describing the flow of heat absorbed or released in the system in the above components, the heat absorbed by the evaporation of the refrigerant in the evaporator 10 is dissipated by the condensation of the refrigerant in the condenser 12 to eventually achieve the effect of cooling. This process is described in the diagram of PH, which is commonly used in thermodynamic refrigeration cycles, along with a description of the flow of refrigerant.

2 is a P-H diagram of a conventional refrigerator.

Referring to FIG. 2, the low-pressure gas refrigerant ST 1 discharged from the evaporator (see 10 of FIG. 1) becomes a high-temperature, high-pressure gas refrigerant ST 2 while passing through the compressor (see 11 of FIG. 1). The amount of work applied (W) is the product of the mass flow rate (m kg / s) and the change in enthalpy ((h _2- h ₁ ) kcal / kg), which is expressed by the following equation (1).

W (kcal / s) = m (kg / s) * (h ₂ -h ₁ ) (kcal / kg)

The high temperature and high pressure gas refrigerant (ST 2) passing through the compressor (see 11 of FIG. 1) discharges heat through the condenser (see 12 of FIG. 1), and the total heat quantity (Q _H ) discharged is the mass flow rate ( m kg / s) times the change in enthalpy ((h _3- h ₂ ) kcal / kg), which is expressed as Equation 2 below.

Q _H (kcal / s) = m (kg / s) * (h ₃ -h ₂ ) (kcal / kg)

The low temperature and high pressure liquid refrigerant (ST 3) passing through the condenser (see 12 of FIG. 1) is expanded through the expander (see 13 of FIG. 1), and serves to reduce the pressure while maintaining the same enthalpy in the expansion process. Therefore, the refrigerant ST 3 passing through the condenser (see 12 in FIG. 1) and the refrigerant ST 4 passing through the expander (see 13 in FIG. 1) are the same (h ₄ = h ₃ ) in enthalpy.

Finally, the heat is absorbed while passing through the evaporator (10 in FIG. 1), wherein the amount of heat absorbed (Q _L ) is the enthalpy (h ₄ ) of the refrigerant (ST 4) passing through the expander (see 13 in FIG. 1). ) And the enthalpy difference of the enthalpy (h ₁ ) of the refrigerant (ST 1) passing through the evaporator (see 10 in FIG. 1), which is expressed by Equation 3 below.

Q _L (kcal / s) = m (kg / s) * (h ₁ -h ₄ ) (kcal / kg)

As described above, in the conventional refrigeration system, the amount of heat (Q _L ) absorbed through the evaporator (see FIG. 1) and the amount (W) applied through the compressor (see 11 in FIG. 1) are condensers (see FIG. 1). It is composed of a cycle that discharges with the amount of heat discharged (Q _H ), and a lot of heat of absorption of the evaporator (Q _L ) assuming that the same amount of compressor (W) is applied to increase the efficiency of the refrigeration refrigeration system. The system must be configured to absorb the water.

By the way, in the conventional refrigeration refrigeration system in the evaporator absorption heat (Q _L ) given as shown in Equation 3, the expansion valve (see 13 in Fig. 1) is subjected to an enthalpy process, so that the expansion (see 13 in Fig. 1) The enthalpy h ₄ of the refrigerant ST 4 that has passed through causes an expansion loss equal to the enthalpy h ₃ of the refrigerant ST 3 before passing through the expansion valve (see 13 in FIG. 1). There is a limit to increasing the evaporator heat of absorption (Q _L ), which reduces the efficiency of the system.

In addition, the conventional freezer refrigeration system having the configuration as described above is the only way to stop the system because there is no other method when it is no longer required to lower the temperature to reach the appropriate temperature in the refrigerating chamber or freezing chamber. That is, the compressor is repeatedly turned on and off, and the frequent stoppage of the refrigeration system generates cycle loss, which in turn causes a decrease in the efficiency of the refrigeration system.

The present invention has been made to improve the above problems, and provided with an inflator capable of reducing the expansion loss, the freezer refrigeration can adjust the amount of refrigerant circulated in the entire refrigeration refrigeration system in accordance with the conditions of the refrigeration load It is an object to provide a system.

1 is a block diagram of a conventional refrigeration system.

2 is a P-H diagram of a conventional refrigeration system.

Figure 3 schematically shows the ejector used in the present invention.

Figure 4 is a block diagram of a first embodiment of a refrigeration system provided with a side pipe and an ejector according to the present invention.

5 is a P-H diagram of a refrigeration system provided with a side pipe and an ejector according to the present invention.

Figure 6 is a view showing another embodiment of the refrigeration refrigeration system provided with a side pipe and an ejector according to the present invention.

<Description of the symbols for the main parts of the drawings>

10, 35 .............. Evaporator 11, 31 ......... Compressor

12, 32 .............. Condenser 13 ............. Expander

21 .................. Drive Fluid Inlet

22 ............. Suction fluid inlet 27 ............. Fluid outlet

23 .................. Nozzle section 24 ............. Mixing section

25 ............... Constant Area Section

26 ............. Diffuser section 33 ............. Ejector for expansion

34 .................. Gas separator 33a ............ Expansion valve

36 .................. Compressor Side Tube

37 .................. Compressor Side Valve 38 ............. Reducing Device

38a .............. Ejector for pressure reduction

In order to achieve the above object, a refrigeration system equipped with a side pipe and an ejector according to the present invention comprises: an evaporator configured to discharge gas refrigerant having a low pressure by absorbing external heat after a low pressure liquid refrigerant is introduced; A compressor for compressing the low pressure gas refrigerant evaporated in the evaporator and discharging the gas refrigerant to high temperature and high pressure gas refrigerant; A condenser that cools the high temperature and high pressure gas refrigerant compressed by the compressor by an external cooling means and discharges the low temperature and high pressure liquid refrigerant; In the refrigeration refrigeration system comprising an expander for expanding the low-temperature high-pressure liquid refrigerant condensed in the condenser to make a low-pressure liquid refrigerant to the evaporator,

A compressor side pipe configured to bypass the flow of refrigerant to be discharged to the outlet of the compressor between the compressor and the condenser; A compressor side pipe valve inserted into an inlet of the side pipe to adjust an amount of refrigerant flowing into the side pipe; A pressure reducing device inserted into a side pipe extending from the valve to lower the pressure of the refrigerant; The expander may include an expansion ejector configured to suck together a high-pressure driving fluid discharged from the condenser and a low-pressure suction fluid from the evaporator to discharge at a proper pressure; The evaporator is divided into two strands at the refrigerant outlet, and a conduit is provided to introduce the refrigerant into the compressor and the expansion ejector, respectively.

3 is a view schematically showing an ejector used in the present invention.

Referring to the configuration of the ejector is an important component in the refrigeration refrigeration system provided with the ejector and the side pipe according to the present invention with reference to Figure 3, the ejector has a total of three holes, one in the front, side, the rear as a whole The hole is the driving fluid inlet 21, the hole at the side is the suction fluid inlet 22, and the hole at the rear is the fluid outlet 27.

In addition, the configuration of the ejector together with the flow of the fluid, the configuration of the ejector can be divided into four zones, first, the nozzle section (Nozzle Section) 23 is the driving fluid inlet 21 and enlarged contraction The nozzle is sequentially accelerated to a supersonic state as the high-pressure driving fluid passes, and the pressure of the driving fluid is lower than that of the suction fluid due to the increased speed.

A mixing section 24 is provided after the nozzle section 23, and the mixing section 24 opens the suction fluid inlet 22 due to the pressure of the lowered driving fluid. The suction fluid is sucked through the driving fluid and the suction fluid are mixed with each other, and maintain the state of the supersonic speed as in the nozzle section (23).

A constant area section 25 is provided after the mixing section 24. The constant area section 25 is a straight tube with no change in cross-sectional area, in which it enters the supersonic state. Due to the difference between the fluid pressure and the outlet pressure, a vertical shock wave is generated.

After the constant area section 25, there is a diffuser section 26, which is a part of the fluid discharge, which is in the form of a tube, which reduces the velocity of the fluid as it passes through. And the pressure is raised.

With reference to the ejector described above will be described an embodiment in which the refrigerating system provided with the side pipe and the ejector according to the present invention can exhibit the best effect.

Figure 4 is a block diagram of a first embodiment of a refrigeration system provided with a side pipe and an ejector according to the present invention.

Referring to Figure 4, the refrigeration refrigeration system provided with the side pipe and the ejector according to the present invention passes through the compressor (Compressor) 31, the compressor (Compressor 31) for making a low-pressure gas refrigerant to a high-temperature high-pressure gas refrigerant A condenser 32, which cools a gas of a high temperature and high pressure to form a liquid refrigerant of low temperature and high pressure, uses a low temperature and high pressure liquid refrigerant that has passed through the condenser 32 as a driving fluid, and an evaporator. After the evaporation in the (35), the expansion ejector (33) and the expansion ejector (33) for the expansion in place of the inflator to make a proper pressure using a low-pressure gas refrigerant as the suction fluid It is inserted between the gas-liquid separator 34 which separates only the refrigerant in the liquid state from the refrigerant mixed in the gas-liquid state at an appropriate pressure, and the expansion ejector 33 and the gas-liquid separator 34 to accurately expand the refrigerant. Fang An evaporator 35 which absorbs heat by evaporating the liquid refrigerant filtered through the valve 33a and the gas liquid separator 34, and bypasses the flow of the refrigerant between the compressor and the condenser. Compressor side pipe (36) that can be discharged to the outlet, the compressor side pipe (37) for controlling the amount of refrigerant flowing into the side pipe at the inlet of the side pipe, compressor side pipe extending from the compressor side pipe valve ( 36) is characterized in that it consists of a pressure reducing device (38) provided to reduce the pressure of the refrigerant.

However, even if the expansion valve 33a, the gas-liquid separator 34 is deleted, only the efficiency of the refrigerator, etc. is involved, and the operation of the refrigeration refrigeration system is not affected.

When describing the pressure reducing device 38, which is one characteristic part of the present invention in detail, the pressure reducing device 38 is subjected to a process of reducing the high temperature and high pressure liquid refrigerant flowing through the compressor 31. Afterwards, it is sent to the compressor 31. When such a pressure reducing device 38 is used, when the heat load is large, the compressor side pipe valve 37 is closed to reduce the amount of refrigerant flowing into the pressure reducing device 38, and the load In the case of small, the inconvenience of turning on and off the system is eliminated by turning off the compressor side pipe valve 37 to increase the amount of refrigerant flowing into the pressure reducing device 38.

In addition, as described above, the refrigerant decompressed from the compressor 31 by using the decompression device 38 and depressurized through the decompression device 38 is mixed at the inlet of the compressor 31 so as to increase the pressure of the refrigerant entering the compressor 31. Helped.

5 is a P-H diagram of a refrigeration system provided with a side pipe and an ejector according to the present invention.

4 and 5, the low-pressure gas refrigerant ST 10 passing through the gas-liquid separator 34 and the evaporator 35 becomes a high-temperature, high-pressure gas refrigerant ST 20 while passing through the compressor 31. The refrigerant, which has become the high temperature and high pressure gas refrigerant (ST 20) through the compressor (31), is deprived of heat while passing through the condenser (32) to become a low temperature and high pressure liquid refrigerant (ST 30), and the condenser (32) The refrigerant, which has become a low temperature and high pressure liquid refrigerant (ST 30) while passing through, enters the expansion ejector (33) to serve as a driving fluid, and the low pressure gas refrigerant (ST 10) passing through the evaporator 35 is used for expansion. After entering the ejector 33 and acting as a suction fluid, the gas-liquid mixed refrigerant ST 40 of low temperature and low pressure is finally discharged, and the gas-liquid mixed refrigerant ST 40 discharged from the expansion ejector 33 is an expansion valve ( After excess expansion in 33a), gas and liquid are separated in the gas-liquid separator 34, The sieve refrigerant ST 10 is introduced into the compressor 31 to complete the cycle, the liquid refrigerant ST 50 is introduced into the evaporator 35, and the evaporator is separated from the gas-liquid separator 34. ) Absorbs heat and evaporates to a low pressure gas refrigerant (ST 10), the evaporated gas refrigerant (ST 10) is branched at the exit of the evaporator 35, and part of it is used as the suction fluid of the expansion ejector (33), Is introduced into the compressor 31 to complete the cycle.

With reference to the flow of the refrigerant as described above will be described in detail the ejector 33, which is a characteristic part of the refrigeration refrigeration system provided with the side pipe and the ejector according to the present invention.

The expansion ejector 33 is a high-temperature, high-pressure liquid refrigerant (ST 30) discharged from the condenser 32 is introduced into the drive fluid, the low-pressure liquid refrigerant (ST 10) discharged from the evaporator 35 is a suction fluid And the driving fluid and the suction fluid are mixed and discharged into the low-temperature low-pressure gas-liquid mixed refrigerant (ST 40). The characteristic role of the expansion ejector 33 is a capillary tube, which has been used as a conventional expansion valve. In contrast, the process is not an isoenthal process.

Since the expansion process of the expansion ejector 33 is not such an enthalpy process, when the conventional capillary tube is applied, the enthalpy becomes smaller than the state after expansion (ST 60). This process is further strengthened through the gas-liquid separator (see 34 in FIG. 4) so that only the refrigerant enthalpy (ST 50) in the liquid state (50) is introduced into the evaporator 35.

Let us introduce another embodiment of a refrigeration system provided with a side pipe and an ejector according to the present invention.

6 is a view showing another embodiment of a refrigeration refrigeration system provided with a side pipe and an ejector according to the present invention.

Referring to Figure 6, the freezing built-in system is provided with the side pipe and the ejector according to the present invention is almost the same as the first embodiment, but the characteristic part is a pressure reducing ejector 38a is used as a pressure reducing device, the evaporator 35 of the outlet The pipeline is provided with a branched branch, not two, that enters the suction fluid inlet of the reduced-pressure ejector 38a, the suction fluid inlet of the expansion ejector 33, and the inlet of the compressor 31. A pipeline is provided, and a control valve can be inserted into the pipeline.

Referring to the operation of another embodiment of the refrigeration refrigeration system provided with the side pipe and the ejector according to the present invention having the above configuration, the decompression ejector 38a is a high-pressure high-pressure gas refrigerant flowing out of the compressor 31 for the decompression The ejector 38a flows into the driving fluid, the low pressure liquid refrigerant flowing out of the evaporator 35 flows into the suction fluid, and the driving fluid is mixed under reduced pressure to flow out to the inlet of the compressor 31.

By using the pressure reducing ejector 38a as a device for mixing the fluid as described above, it is possible to increase the pressure at the inlet of the compressor 31 more, and the operation of the pressure rise in detail as follows. .

When the amount of refrigerant circulated throughout the refrigerating cycle including the evaporator 35 is small, that is, when the amount of refrigerant bypassed through the compressor side pipe valve 37 is large, Although the absolute amounts are the same, the work required for the compressor 31 by increasing the pressure of the refrigerant flowing into the compressor 31 becomes smaller than that of the conventional refrigeration refrigeration system.

In addition, when the amount of refrigerant circulated throughout the refrigerating cycle including the evaporator 35 is large, that is, when the amount of refrigerant bypassed through the compressor side pipe valve 37 is small, the refrigerant 31 is introduced into the compressor 31. The absolute amount of the refrigerant is the same, but the work required by the compressor 31 is greater than when the amount of refrigerant to be bypassed is large.

As can be seen through the flow of the refrigerant, the refrigeration refrigeration system provided with the side pipe and the ejector according to the present invention can increase the heat of absorption of the evaporator by reducing the expansion loss by using the expansion ejector as an expander, By using a pressure-reducing ejector, the amount of refrigerant circulated in the refrigerating and freezing system can be freely adjusted according to the load of the refrigeration, thereby making it possible to flexibly respond to the refrigeration load.

The refrigeration refrigeration system equipped with the side pipe and the ejector according to the present invention is to freely adjust the amount of refrigerant circulated in the refrigeration cycle in accordance with the refrigeration load to prevent cyclic loss (Cyclic Loss) caused by frequent shutdown of the system By circulating the refrigerant at the same mass flow rate, the same work of the compressor can be absorbed, and more heat can be absorbed and released to the outside.When designing with the same amount of heat absorption, the mass flow rate is reduced to reduce the work of the compressor. Can consequently improve the efficiency of the system.

Claims (8)

An evaporator which absorbs heat from outside after the low pressure liquid refrigerant is introduced and discharges the low pressure gas refrigerant; A compressor for compressing the low pressure gas refrigerant evaporated in the evaporator and discharging the gas refrigerant to high temperature and high pressure gas refrigerant; A condenser that cools the high temperature and high pressure gas refrigerant compressed by the compressor by an external cooling means and discharges the low temperature and high pressure liquid refrigerant; In the refrigeration refrigeration system comprising an expander for expanding the low-temperature high-pressure liquid refrigerant condensed in the condenser to make a low-pressure liquid refrigerant to the evaporator, A compressor side pipe configured to bypass the flow of refrigerant to be discharged to the inlet of the compressor between the compressor and the condenser; A compressor side pipe valve inserted into an inlet of the compressor side pipe to adjust an amount of refrigerant flowing into the side pipe; A pressure reducing device inserted into the compressor side pipe extending from the compressor side pipe valve to reduce the pressure of the refrigerant; The expander may include an expansion ejector configured to suck together a high-pressure driving fluid discharged from the condenser and a low-pressure suction fluid from the evaporator to discharge at a proper pressure; The evaporator is branched into two strands at the refrigerant outlet, and a pipeline is provided to introduce refrigerant into the compressor and the expansion ejector, respectively, so that the amount and pressure of the refrigerant circulated in the entire refrigeration refrigerating cycle are adjusted. Refrigeration system. The method of claim 1, And a gas-liquid separator is installed between the expansion ejector and the evaporator so that the liquid refrigerant flows into the evaporator and the gas refrigerant flows into the compressor. The method according to claim 1 or 2, A refrigeration refrigeration system provided with a side pipe and an ejector, characterized in that an expansion valve is inserted into the auxiliary expansion device connected to the outlet of the expansion ejector to accurately reduce the pressure of the refrigerant. The method of claim 1, Refrigeration refrigeration system provided with a side pipe, characterized in that the capillary tube is used as the decompression device. The method of claim 1, Refrigeration refrigeration system provided with a side pipe, characterized in that the expansion valve is used as the decompression device. An evaporator which absorbs heat from outside after the low pressure liquid refrigerant is introduced and discharges the low pressure gas refrigerant; A compressor for compressing the low pressure gas refrigerant evaporated in the evaporator and discharging the gas refrigerant to high temperature and high pressure gas refrigerant; A condenser that cools the high temperature and high pressure gas refrigerant compressed by the compressor by an external cooling means and discharges the low temperature and high pressure liquid refrigerant; In the refrigeration refrigeration system comprising an expander for expanding the low-temperature high-pressure liquid refrigerant condensed in the condenser to make a low-pressure liquid refrigerant to the evaporator, A compressor side pipe configured to bypass the flow of the refrigerant between the compressor and the condenser to be discharged to the inlet of the compressor; A compressor side pipe valve inserted into an inlet of the compressor side pipe to adjust an amount of refrigerant flowing into the side pipe; A pressure reducing ejector connected to the compressor side pipe valve to allow the refrigerant of low pressure and high pressure to flow in and out; The expander may include an expansion ejector configured to suck together a high-pressure driving fluid discharged from the condenser and a low-pressure suction fluid from the evaporator to discharge at a proper pressure; And The evaporator is branched into three strands at the outlet, respectively, the refrigeration refrigeration system provided with a side pipe and an ejector, characterized in that the inlet is provided with a suction fluid inlet, a suction fluid inlet of the expansion ejector, an inlet for the inlet, the compressor inlet. The method of claim 6, And a gas-liquid separator is installed between the expansion ejector and the evaporator so that the liquid refrigerant flows into the evaporator and the gas refrigerant flows into the compressor. The method according to claim 6 or 7, A refrigeration refrigeration system provided with a side pipe and an ejector, characterized in that an expansion valve is inserted into the auxiliary expansion device connected to the outlet of the expansion ejector to accurately reduce the pressure of the refrigerant.