JP2001200765A - Fuel-cooling method in gasoline engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel-cooling method in a gasoline engine, capable of always properly holding an injection amount of fuel per injection time, by preventing generation of fuel boiling bubbles caused by a temperature rise of fuel in the gasoline engine. SOLUTION: A heat exchanger lowering down a fuel temperature to a degree less than a boiling bubble generating temperature is arranged halfway of a fuel pipe. This heat exchanger, constituted by a sealed vessel, the fuel pipe arranged to be inserted in this sealed vessel to stick a wick material having a capillary structure in a pipe surface in the vessel, a heat medium fluid sealed in the sealed vessel, and a cooling part or a suction part to the outside, is formed to serve as a mechanism warming the heat medium fluid in the sealed vessel by heat energy of fuel at a high temperature in the fuel pipe vaporized to condense this vaporized flow in the cooling part returned to the original heat medium fluid or sucked to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cooling method for preventing the generation of bubbles due to fuel boiling of a gasoline engine during high temperature, high heat, or extreme heat, which is remarkable in a summer or a hot climate. .

[0002]

2. Description of the Related Art A fuel pump is used for supplying fuel to a fuel injection device of a gasoline engine in order to more reliably supply fuel. With the increase in engine output and the development of the gasoline injection device, various pump systems have been used. Although it is used, especially in summer or when the temperature is extremely high or extremely hot in countries with hot climates, heat is transmitted from the engine or exhaust system parts during the process of being sent from the fuel tank to the fuel injection device. When the temperature of the fuel becomes high and the fuel temperature exceeds the boiling point, bubbles (vapor) start to be generated in the fuel. When air bubbles are generated in the fuel, the air bubbles are mixed into the fuel injected into the cylinder by the fuel injection device, and the fuel injection amount per injection time is reduced, so that a predetermined output cannot be obtained. Was. Excess fuel that has not been combusted by the engine is returned to the tank via the return pipe.However, it passes through the vicinity of the high temperature part of the engine and is heated to become high-temperature return gasoline. The temperature of the air was raised, and it was released as vapor from the tank, which could cause problems such as air pollution and gasoline smell in the cabin.

As a countermeasure, a method of cooling a fuel supply pipe between a fuel tank and a fuel injection device by a pipe of an air conditioner (air conditioner) of an automobile to lower the fuel temperature to below the boiling point has been adopted. However, the method of lowering the fuel temperature using an air conditioner causes an increase in the size of the compressor and condenser of the air conditioner and deterioration of fuel efficiency, and the fuel temperature can be lowered only when the air conditioner is driven. There is a disadvantage that the fuel temperature cannot be lowered when the engine is stopped.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional problems, and it is necessary to reduce fuel consumption during running regardless of whether the air conditioner is driven or not. It is an object of the invention to propose a fuel cooling method that can lower the fuel temperature below the boiling point accordingly.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a fuel cooling means for preventing generation of fuel boiling bubbles due to a rise in the temperature of fuel in a gasoline engine. A heat exchanger for lowering the temperature to below the boiling bubble generation temperature is provided. The heat exchanger is provided with a sealed container, and a wick material which is piped through the sealed container and has a capillary structure on a surface of the pipe in the container. Fuel pipes,
A heat medium fluid and a cooling unit sealed in the closed container, and penetrates through the closed container while the heat medium fluid in the closed container rises in the capillary of the wick material by surface tension. The fuel is evaporated by the thermal energy of the high-temperature fuel in the fuel pipe, the temperature of the fuel is reduced to a temperature lower than the boiling bubble generation temperature by the latent heat of vaporization at that time, and the evaporating flow of the heat medium fluid is condensed in the cooling unit and is returned to the original heat medium. In the second embodiment, a heat exchanger for lowering the fuel temperature to below the boiling bubble generation temperature is provided in the middle of the fuel pipe, and the heat exchanger is provided with a closed vessel, A fuel pipe which is piped through the closed vessel and has a wick material having a capillary structure attached to a pipe surface in the vessel, and a suction unit for evaporating a heat medium fluid sealed in the closed vessel to the outside And from While the heat medium fluid in the closed container rises in the capillary of the wick material by surface tension, it is evaporated by the heat energy of the high-temperature fuel in the fuel pipe penetrating the closed container, and the vaporization at that time is performed. Latent heat lowers the temperature of the fuel below the boiling bubble generation temperature,
The evaporating flow of the heat medium fluid is suctioned to the outside from the suction part, and the suction part to the outside is an intake manifold. Further, as the heat medium fluid, any one of gasoline, water, a mixed liquid of water and alcohol, a mixed liquid of water and ether, Freon, and alternative Freon can be used.

That is, the heat exchanger in the present invention utilizes the latent heat of vaporization of the heat medium fluid. The heat exchanger in the closed container rises in the capillary of the wick material due to surface tension while the high-temperature fuel flows. Heated by the thermal energy of the vaporized and evaporated, the evaporation pressure of the heating unit space is reduced by the action of the cooling unit and the suction unit at that time, the evaporation is promoted to take the latent heat of vaporization and cool the fuel pipe, The evaporating flow of the heat medium fluid flows to a cooling section having a low pressure, is cooled and condensed, and returns to the original liquid or is sucked outside. Therefore, according to this heat exchanger, it is possible to lower the temperature of the fuel to a temperature lower than the boiling bubble generation temperature as required, regardless of whether the air conditioner is driven or not, and this is caused by the rise in the fuel temperature of the gasoline engine. By preventing the generation of fuel boiling bubbles, bubbles are prevented from being mixed into the fuel injected into the cylinder by the fuel injection device, and the fuel injection amount per injection time can always be kept appropriate. Becomes In the present invention, the heat exchanger as described above is used in order to suppress an increase in the size of a compressor and a condenser of an air conditioner and an increase in fuel efficiency.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view showing a first embodiment apparatus for carrying out the method of the present invention, and FIG. 1C, 1
1A, 11B and 11C are fuel pipes, 2 and 12 are heat exchangers, 3 and 13 are fuel tanks, 4 and 14 are wick materials,
5 and 15 are fuel (gasoline), 6 is a heat medium fluid (liquid), 7 and 17 are heat medium fluid pipes, 8 and 18 are fuel pumps, 9 is a fuel injection device, 10 is an evaporative flow pipe, and 20 is an intake manifold. , 21 is a cylinder head, 22 is an intake valve, 23 is a valve stem, 24 is a piston, 25 is a combustion chamber, 26 is a cylinder block, V1 to V1.
V4 is an on-off valve.

In FIG. 1, a heat exchanger 2 includes a fuel tank 3
And a fuel pipe 1B which is branched and connected to a fuel pipe 1A between the fuel injection device 9 and the fuel injection device 9. The structure thereof is a closed vessel 2-1 and a pipe 2-2 communicating between a top and a bottom of the vessel. A cooling unit 2-4 having a part of the piping as a fin tube 2-3; and a heat medium fluid 6 sealed in a closed container 2-1.
And a fuel pipe 1B that is piped through the closed vessel 2-1 and has a wick material 4 having a capillary structure attached to the pipe surface in the vessel, and heat connected to the bottom of the closed vessel 2-1. The heat medium fluid 6 is injected from the medium fluid pipe 7 into the closed container 2-1 via the on-off valve V1. Further, as shown by an arrow, cooling air is applied to the cooling section 2-4 composed of the fin tubes 2-3 from outside, and the evaporative flow in the fin tubes 2-3 is condensed and the original liquid is removed. It is a mechanism to return to. The other end of the fuel pipe 1B penetrating the sealed container 2-1 is connected to an on-off valve V
The fuel is cooled by the heat exchanger 2 and supplied to the fuel injection device 9 through the fuel pipe 1A. The fuel injection device 9 includes a delivery pipe 9-1 and an injector 9-2. Note that an on-off valve V3 is provided in the fuel pipe 1A in consideration of the case where it is not necessary to cool the fuel.

In the above arrangement, the fuel 5 in the fuel tank 3 is supplied by the fuel pump 8 to the fuel injection device 9 via the fuel pipe 1A or 1B. In this case, when the outside air temperature is high and the temperature of the fuel supplied to the fuel injection device 9 rises above the boiling point and there is a risk of causing boiling, the on-off valve V3 on the fuel pipe 1A side is closed and the fuel pipe 1 is closed.
The on-off valve V2 on the B side is opened to allow the fuel 5 in the fuel tank 3 to flow through the heat exchanger 2. At this time, the heat medium fluid 6 supplied from the heat medium fluid pipe 7 via the on-off valve V1 and sealed in the closed container 2-1 causes the surface tension of the heat medium fluid 6 to flow through the inside of the capillary of the wick material 4. And evaporates while being heated by the thermal energy of the high-temperature fuel in the fuel pipe 1B, and the evaporating flow is sealed
1 through the pipe 2-2 from the top of the fin tube 2-3
Is condensed in the cooling unit 2-4, and returns to the original heat medium fluid 6 and circulates into the closed vessel 2-1. On the other hand, the fuel flowing in the fuel pipe 1B is deprived of heat by the evaporation of the heat medium fluid 6 in the heat exchanger 2 and is supplied to the fuel injection device 9 at a temperature lower than the bubble generation temperature. Therefore, it is possible to prevent air bubbles from being mixed in the fuel injected into the cylinder by the fuel injection device 9, and to always keep the fuel injection amount per injection time properly.

On the other hand, when the outside air temperature is low and the temperature of the fuel supplied to the fuel injection device 9 is lower than the bubble generation temperature, there is no need to lower the fuel temperature, so the on-off valve V2 on the fuel pipe 1B side is closed. The on-off valve V3 on the fuel pipe 1A side is opened, and the fuel is directly supplied from the fuel pipe 1A to the fuel injection device 9.

Next, FIG. 2 shows an example of a system in which fuel 15 is used as a heat medium fluid and this fuel is sucked into an intake manifold 20 as an evaporative flow. The fuel pipe 13 is provided in the middle of a fuel pipe 11A that supplies the fuel to the fuel tank 13. The structure of the fuel pipe 13 penetrates the sealed container 12-1, the fuel 15 sealed in the sealed container 12-1, and the sealed container 12-1. And a fuel pipe 11A-1 having a wick material 14 having a capillary structure attached to the surface of the pipe in the vessel, and a branch pipe in the middle of a fuel pipe 11B for supplying the fuel 15 in the fuel tank 13 to the engine. The fuel 15 is injected into the closed vessel 2-1 from the fuel pipe 11C via the on-off valve V4. The other end of the evaporative flow pipe 10 connected to the top of the closed vessel 12-1 is connected to the intake manifold 20, so that the evaporative flow is sucked into the intake manifold 20. When water other than fuel, for example, water is used as the heat medium fluid, the heat medium fluid pipe 17 is connected to the sealed container 12-1, and the on-off valve V4 of the fuel pipe 11C is closed or the fuel pipe 11 is closed.
It is also possible to omit the C and the on-off valve V4 and supply water from the heat medium fluid pipe 17 into the sealed container 12-1.

In the apparatus shown in FIG. 2, the fuel 15 in the fuel tank 13 is supplied by a fuel pump 18 to a fuel pipe 11B.
And supplied to the engine. At this time, the fuel pipe 11
The on-off valve V4 of C is in a closed state, and the closed container 12-
A certain amount of fuel 15 is stored in 1. Of the fuel 15 supplied to the engine, the high-temperature return fuel from the engine flows through the heat exchanger 12 from the fuel pipe 11A, returns to the fuel tank 13 again, and is used for circulation. When passing through the closed container 12-1, the fuel 15 sealed in the closed container 12-1 rises in the capillary of the wick member 14 due to the surface tension of the fuel 15, and the closed container 12-1 Is heated by the thermal energy of the high-temperature fuel in the fuel pipe 11A-1 and evaporates, and the evaporative flow is sent from the top of the closed vessel 12-1 via the evaporative flow pipe 10 to the intake manifold 20.
Is sucked into. On the other hand, the fuel flowing through the fuel pipe 11A-1 is deprived of heat by the evaporation of the fuel 15 in the closed vessel 12-1, and is supplied to the fuel tank 13 at a temperature lower than the boiling temperature.

According to the present invention, the apparatus shown in FIG. 1 and the apparatus shown in FIG.
When the vehicle is stopped, the fuel can be cooled by the suction method shown in FIG. 2, and when the vehicle is running, it can be cooled by the heat exchanger 2 shown in FIG.

As described above, the heat medium fluid 6 sealed in the closed vessel 2-1 of the heat exchanger 2 includes gasoline, water, a mixed liquid of water and alcohol, a mixed liquid of water and ether, Freon, Any of Freon can be used.

[0015]

As described above, according to the method of the present invention, the use of the heat exchanger of the type that lowers the fuel temperature by using the heat energy of the fuel flowing through the fuel pipe makes it possible to use the heat exchanger for driving a car or for controlling an air conditioner. The fuel temperature can be reduced to a temperature lower than the boiling bubble generation temperature as needed, regardless of whether the fuel is driven or not, so that the generation of fuel boiling bubbles due to a rise in the temperature of the gasoline engine fuel can be prevented. As a result that bubbles are prevented from being mixed into the fuel injected into the cylinder by the injection device, the fuel injection amount per injection time can always be appropriately maintained. Therefore, the present invention is extremely effective especially for vehicles having high temperature and high heat specifications in summer or in a country with a hot climate.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a first embodiment apparatus for carrying out the method of the present invention.

FIG. 2 is a schematic diagram showing a second embodiment apparatus for carrying out the method of the present invention.

[Explanation of symbols]

 1A, 1B, 1C, 11A, 11B, 11C Fuel pipe 2, 12 Heat exchanger 3, 13 Fuel tank 4, 14 Wick material 5, 15 Fuel (gasoline) 6 Heat medium fluid 7, 17 Heat medium fluid pipe 8, 18 Fuel pump 9 Fuel injection device 10 Evaporation flow pipe 20 Intake manifold 21 Cylinder head 22 Intake valve 23 Valve stem 24 Piston 25 Combustion chamber 26 Cylinder block V1-V4 On-off valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02M 53/00 F02M 53/00 C 55/02 350 55/02 350G

Claims (4)

[Claims] 1. A fuel cooling method for preventing generation of fuel boiling bubbles due to a rise in fuel temperature of a gasoline engine, wherein the heat exchanger lowers the fuel temperature in a fuel pipe to a temperature lower than the boiling bubble generation temperature. The heat exchanger is provided with a closed vessel, a fuel pipe that is piped through the closed vessel and has a wick material having a capillary structure attached to a pipe surface in the vessel, and sealed in the closed vessel. The heat medium fluid in the closed container is heated by the surface tension in the capillary tube of the wick material while the heat medium fluid in the closed container rises due to surface tension. A mechanism in which the fuel is evaporated by the thermal energy of the fuel, the temperature of the fuel is reduced to below the boiling bubble generation temperature by the latent heat of vaporization at that time, and the evaporating flow of the heating medium fluid is condensed in the cooling unit and returns to the original heating medium fluid. A fuel cooling method for a gasoline engine, characterized by the following: 2. A fuel cooling method for preventing the generation of fuel boiling bubbles due to a rise in fuel temperature of a gasoline engine, wherein the heat exchanger lowers the fuel temperature below the boiling bubble generation temperature in the middle of a fuel pipe. The heat exchanger is provided with a closed vessel, a fuel pipe that is piped through the closed vessel and has a wick material having a capillary structure attached to a pipe surface in the vessel, and sealed in the closed vessel. And a suction unit for evaporating the flow of the heat medium fluid to the outside. The heat medium fluid in the closed container rises through the capillary of the wick material by surface tension and penetrates through the closed container. The fuel is evaporated by the heat energy of the high-temperature fuel in the fuel pipe, and the temperature of the fuel is reduced to below the boiling bubble generation temperature by the latent heat of vaporization at that time, and the evaporating flow of the heat medium fluid is sucked outside from the suction part. A fuel cooling method for a gasoline engine, wherein the fuel cooling method is used. 3. The fuel cooling method for a gasoline engine according to claim 2, wherein the external suction unit is an intake manifold. 4. The heat medium fluid includes gasoline, water,
Mixed liquid of water and alcohol, mixed liquid of water and ether,
The fuel cooling method for a gasoline engine according to any one of claims 1 to 3, wherein one of CFCs and CFCs is used.