JPS60500341A - How to run an engine with high heat of vaporization fuel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] How to run an engine with high heat of vaporization fuel The present invention uses a fuel that also has a high latent heat of vaporization, such as methanol (σ), to generate sparks. This article relates to a method for converting an ignition-type internal combustion engine. To be more specific, the fuel level is 1) introduced in the first (1) stage to evaporate and atomize its main portion; After that, due to the rapid ignition power, dense air/silence is created near the spark plug. Regarding the engine operating method introduced in the second stage of provision 3-filtration, .

Fuel with high latent heat of vaporization fits 1! Tanuni used in the internal combustion engine of a car Proposed. Methanol is a reciprocating f' stone engine combustion model σ)/, -y)l17) There are candidates for 1st σ). Why, Rabazo has a high mectane value, and it is similar to coal. This is because it can be easily produced from. However, the disadvantages associated with methanol are that J) high evaporation J) latent heat and its low thermal energy calorific value dilutes lubricating oil '1. □ due to piston ring and ring hole θ) its tendency to increase wear. It is towards.

Methanol can be introduced into the engine in a variety of ways.

In the case of vaporized methanol introduction, the high latent heat of vaporization is caused by the suction air passing through the suction device. It is difficult to evenly distribute the fuel into the intake air as it flows to the tank. (This involves applying a large amount of heat to the nudging device. However, a small drop of liquid methanol still enter the cylinder, where they stick to the cylinder wall and cedar dilutes the lubricating oil as a result of wear will be accelerated.

Injection of methanol into the suction manifold using multi-point injection is an alternative method for fuel introduction. This is one possible method.

This method eliminates the cylinder-to-cylinder fuel distribution problem, but Does not eliminate the possibility of oil dilution. In practice, the reduction in time available for evaporation Therefore, and since the exhaust heat is not transferred to methanol, it is the vaporized methanol conductor. would likely increase oil dilution problems relative to

The present invention accomplishes the above by providing a two-stage introduction of methanol into the engine combustion chamber. It concerns an engine operating method that overcomes various drawbacks. In this case, a part of the combustion chamber is connected to the piston. It has a central recess in the front, and the main part of the fuel is injected into the recess to prevent evaporation and atomization. to minimize wetting of the cylinder wall.

It is therefore an object of the present invention to reduce the amount of emissions produced while at the same time reducing the suction charge and High to improve the volumetric efficiency of the engine by cooling the relevant parts of the engine It is the operation of an engine with fuel that has latent heat of vaporization.

One object of the present invention is that the fuel is injected in multiple stages so that the fuel is initially Once heated, the main part of the fuel is properly evaporated and atomized, and then secondly at the point of ignition. Provides a rich air/fuel mixture near the spark plug for a consistent and faithful flame is to operate the engine as described above to ensure the start of the engine.

Methanol or other fuels with high latent heat of vaporization in automotive type vehicles The use of is known. For example, U.S. Pat. No. 4,126,997 to Oswald et al. and U.S. Pat. combustion chamber and a compression ratio of approximately 12:1 to the engine, substantially at the center or axis of the combustion chamber. of 100% methanol in engines with closely located spark plugs. Use is disclosed.

But all of the fuel is injected at the same time, and how do we get the cylinder walls wet? and how the resulting dilution of the lubricating oil is prevented is not explained.

John's US Pat. No. 1,117,810 is a gasoline and methane It describes a device for mixing the combustion chamber or the aforementioned problems. No explanatory power has been given as to how to operate the engine in a manner that avoids this.

U.S. Pat. No. 4,022,165 to Eckert et al. discloses that two separate amounts of fuel are This describes a fuel injection system that injects fuel into the engine with a time delay in between. institution Two separate fuel injection nozzles are used between the two operating units of the same unit (1) operating unit. Inner VC @ A large amount of fuel is injected at first, and then a smaller amount is injected. Ru.

A large amount of fuel is injected deep into the cylinder as a straight jet, while A smaller amount is introduced closer to the ignition flag. However, due to the action of the combustion chamber No explanation has been given regarding this, and the air/fuel No method of timing and movement of the charge is disclosed.

U.S. Pat. No. 672!2,490 to Araya et al. also discloses a two-stage fuel injection system. However, in this device, injection is first performed near the end of the suction or expansion stroke. It occurs at one point and then at one point at the beginning of the compression stroke. This is the invention However, it is unsatisfactory in overcoming the drawbacks mentioned above.

U.S. Patent Nos. 3,216,407 and 3,439,655 to E.I.T. 1 shows a mechanical structure that provides multiple injections of fuel into a combustion engine; However, the machine The method of operating the valve is different from that of the disclosed invention.

Finally, U.S. Patent No. 66.41986 to Fricker et al. Only the bee-shaped baking chamber inside the piston is shown.

Other objects, features and advantages of the invention will be found in the following detailed description and operation of the invention. With reference to a drawing schematically illustrating the structure of an engine utilizing the transfer system. Therefore, it will become clearer.

As mentioned above, using methanol or other fuels with high latent heat of vaporization The traditional drawback of this is that the piston has a bee-shaped recess that cooperates with the combustion chamber. can be overcome by applying a direct fuel injection concept that utilizes multiple injections of fuel.

Such a structure is schematically illustrated in the drawing, and the reading is similar to that of a spark-ignition internal combustion engine. 10 is shown. It has a normal cylinder block 12, which Within the lock a two-stone 14 cooperates with the face 16 of the cylinder head 18 to create a space between them. It is slidably installed so as to define a combustion chamber 20 in the combustion chamber 20 . In this case, the piste The piston 14 has a central recess 2,2 defining a bowl-shaped structure within the piston.

The recess 22 is designed to provide approximately 40-75% of the snapping area and The engine itself has a compression ratio of approximately 16:1 to use methanol fuel most effectively. It operates with.

Cylinder head 18 has conventional intake valves 24 and exhaust valves 26. Valve 24 is moderate Air is supplied through a suction passage 28 designed to obtain a rotation rate of . exhaust Gas is discharged through outlet passage 30. The passage provides better heat preservation It can be lined with ceramic or sheet metal.

A fuel injector, indicated schematically at 32, is located essentially within the combustion chamber 20 above the recess 22. Place the nozzle 34 in the center of the engine head 18. It is placed. The injector is of known type and therefore of its construction and operation. Details are not explained. In this case, no pump is supplied with 34 VC of nozzle. The pressure level is moderate (approximately 18 kg/cm" C260 ps due to the injector) i'))) and the nozzle itself is fitted for the purpose described below. The present invention presents a conical fuel spray with good atomization properties and relatively low penetration properties. Suffice it to say, I will provide it.

The fire flag 36 is located adjacent to the tip of the fuel injection nozzle 34 as shown in the figure. located as close as possible to the center of the combustion chamber so as to protrude.

The piston 14 rotates through a crank angle of approximately 65 degrees after the engine is at the top dead center position. It is shown in the position when Also, as shown by the dashed line, the injection nozzle A conical injection angle of approximately 80° of the fuel reservoir from the fuel tank 34 is shown. If the fuel If it is injected when the piston 14 is located near the top dead center position, it is injected. Virtually all of the fuel goes directly into the recess 22 and therefore does not wet the cylinder walls. That should be obvious. If only a small amount of fuel is injected, then is confined adjacent to provide a rich air-fuel mixture to this area for ignition. do.

The main feature of the invention is that the large charge of fuel is vaporized well before ignition. 5 and can be atomized and provide a reliable air/fuel charge. Proprietary fuel that provides a second charge at the point and location that provides the ignition It is time to adjust the injection.

More specifically, the engine operates with the following combustion method. The engine takes its intake As the stroke begins, the opening of the intake valve 24 allows air to flow through the air with a moderate swirling motion. 1 gas is introduced into the combustion chamber 20. The piston 14 moves from its top dead center position to its As we begin our descent, the first large charge of fuel (approximately 75~ 90%) is injected into the combustion chamber 20 from the nozzle 34.

As already explained, the piston 14 is near its top dead center at the beginning of the intake stroke. Since the piston is located at the 7th position, this entire charge of fuel is directed into the recess 22 of the piston 14. It will be done. The swirling air charge enters the recess 22 to vaporize the fuel and atomize it. Granulate. The fuel is generally complete by the time piston 14 reaches the position shown in the drawings. It is injected at a rapid rate for a short duration so that it can be detected.

That is, the injection of the first part of the pot of fuel occurs after the top dead center position at the beginning of the suction stroke. It ends between about 500 and 60 degrees. As a result, during the remainder of the suction stroke , the piston 14 descends, and further swirling air enters the series through the open intake valve 24. As it enters the tank, the evaporated and atomized fuel mist exits from the recess 22. Scattered outwardly into the remainder of the cylinder space 20. Such a configuration requires a large amount of fuel Possibly eliminating the possibility of the droplet contacting the cylinder wall. because they are The inner chamber wall of the combustion recess 22 is subjected to an outward centrifugal action, where the This is because as they evaporate, they absorb heat from the chamber walls. Also, this suction line Evaporation of fuel floating in the air during engine cooling cools the suction charge, thus cooling the engine. Improve volumetric efficiency. A cooler suction temperature also results in a cooler overall Nycl temperature. resulting in higher temperatures, thereby improving thermal efficiency and producing less heat during combustion. Nitrogen oxides (1X) are reduced.

Evaporation and exposure of the fuel by the air charge and exhaust gases continues throughout the entire intake stroke. Ku. After that, during the latter part of the compression stroke, approximately 3 D' to 5 before the top dead center of the piston. At 0' position, the second smaller (10-25 s) of total fuel charge A portion is injected through nozzle 34. Penetration for such small fuel quantities is low. Therefore, most of this fuel remains near the tip of the injector nozzle 34 and does not point. The air/fuel ratio near the spark plug 36 just before the fire is enriched. This is- Guarantees consistent and faithful flame initiation and for high efficiency combined with NOx control , facilitates lean operation at part load with extensive exhaust gas recirculation (E()R). make it look like Combustion is then initiated by the spark plug.

If all the methanol is injected late in the compression stroke, it will evaporate and The required heat is extracted primarily from the heat of the compressed gas: therefore, the heat required is extracted from the heat of the compressed gas. Significant thermodynamic efficiency losses can occur. The latent heat of vaporization of methanol is about 5% of its calorific value. therefore, the extraction of this heat from the compressed gas is equivalent to a loss of 5% of the heating value of the fuel. Yes.

warpage throughout the suction stroke and/or during the initial part of the compression stroke σ. Contact jetting prevents loss of gas, but it reduces wetting of the cylinder wall and its The associated piston rings and cylinder bores suffer from wear. The present invention A chamber within the piston that atomizes and vaporizes the fuel in a manner that provides good volumetric efficiency. Two-stage fuel injection into the combustion chamber? Party B will eliminate the above problem. child At the same time, the heat required for evaporation is taken from the surrounding cylinder wall and piston surface. , this is a charge that cools them down and then charges them with air or gas. Heat is also extracted from them, which also improves volumetric and thermal efficiency.

In light of the above, the present invention is aimed at: To provide a method for operating an automobile-type internal combustion engine using a fuel having latent heat of , the heat required for evaporation is taken from the inhaled air and the piston surface. It will be understood that Cooling of the inhaled air improves volumetric and thermal efficiency. and reduce NOx production. Cooling the piston increases its durability and to facilitate engine supercharging without resorting to excessive and expensive piston cooling means. Ru.

Furthermore, the ability of fuel to flow directly into the cylinder as provided by the present invention is further improved. Mechanical atomization eliminates the need to supply suction heat, and it is also possible to Ensure fuel distribution. Direct fueling of the main part of the fuel according to the special timing method described Injection minimizes the likelihood that methanol will dilute the oil film on the cylinder wall. Also, the point The second stage injection of a smaller amount of fuel just before the fire results in a lean mixture and high EGR rate. This makes engine operation easier without jeopardizing ignitability.

Although the invention has been shown and described in one preferred embodiment thereof, there are many modifications and variations. and that modifications may be made thereto without departing from the scope of the invention. It will be obvious to those skilled in the art to which this invention pertains.

■(g) International research report

Claims (1)

[Claims] 1. Operating a spark-ignition internal combustion engine using clean fuel with high heat of vaporization A method of , combustion defined between the cylinder head and the top of the piston with a central recess charging the entire fuel charge into the chamber; a first portion such that essentially all of the fuel charge in the first portion is located in the two-stone recess; At the top dead center (TDC) of the piston at the start of the suction stroke so that the injection into the chamber immediately after installation; relatively low penetration at moderate pressure levels; The injection of said first fuel portion has a conical spray pattern that produces a at such high speed that it is terminated after the injection and while still on the suction stroke. and injecting for a short duration; additional swirling air enters said chamber and recess. This causes evaporation and atomization of the fuel charge and removes the fuel charge from the recesses in the chamber. so that the relatively heavy fuel droplets are subjected to centrifugal action against the recess walls. is trapped inside and absorbs heat from the wall and the incoming air. As the pistons continue to descend during the suction stroke to cool them down continue introducing air into the room; ・Low 2 to ensure fuel mixture Penetration allows the entire fuel charge to enter the chamber during the latter part of the engine's compression stroke just before ignition. The method includes: injecting the remaining portion; and igniting the mixture. 2. In the method according to claim 1, the first part of the injected fuel charge minutes constitute approximately 75 to 90% of the total fuel charge, with a small amount of the remaining fuel portion being low is later injected with greater penetration to enrich the air/fuel mixture at the ignition location. The later injected part remains near the tip of the injector in order to Law. (b) In the method according to claim 1, the fuel portion that is injected first and later. But the same fuel injection! The method in which the method is injected through a bottle. 4. The method according to claim 1, wherein the later injected fuel portion comprises: The jet that is injected when the surface of the piston is within approximately 50% of the surface of the top dead center position from 0 to 50%. Law. 5. The method according to claim 1, wherein the injection of the first portion of the fuel is carried out by the piston. During the suction stroke, the piston ends within approximately 60' of crank angle after the top dead center position. said method. 6. The method according to claim 1, in which a rich mixture is formed after injection of the remaining fuel portion. located near the center of the chamber and near the top of the injector nozzle so as to be adjacent to the compound. The method in which combustion is initiated by a spark plug that is turned on. Z. The method according to claim 1, wherein the recess is located in front of the entire width of the chamber. The method described in IF1 has a 75% area from 4Q to 2 or area.