JPS6210415A - Evaporative cooling apparatus of internal-combustion engine - Google Patents

Abstract

PURPOSE:To enable air coming into a system to be discharged automatically by normally communicating the lower part of a reservoir tank provided outside an airtight refrigerant circulating system with one part of the lower tank of a condenser located higher than a refrigerant outlet through an auxiliary refrigerant passage. CONSTITUTION:In the case of the apparatus stated in the title, liquid-phase refrigerant stored up to the specified level in a water jacket 2 is heated during the operation of an internal-combustion engine 1, and the internal-combustion engine 1 is cooled by taking heat away when the refrigerant is boiled and vaporized. Then, the produced refrigerant vapor is cooled and condensed in a condenser 3, stored in a lower tank 18, and forced to flow back to the water jacket 2 by the operation of a refrigerant supply pump 4. In this case one end of an auxiliary refrigerant passage 25 is connected to one part of the lower tank 18 located higher than a refrigerant outlet 18a, and the other end is connected to a reservoir tank 23 open to the atmosphere. Also, a cooling fan 19 is provided adjoiningly to the condenser 3, and is controlled to operate according to the output of a temperature switch 20 mounted on the lower tank 18.

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a boiling cooling device for an internal combustion engine that stores liquid phase refrigerant up to a predetermined level in a water jacket and cools various parts of the internal combustion engine by boiling and vaporizing the liquid phase refrigerant. In particular, the present invention relates to a boiling cooling device in which air, which is a non-condensable gas, is naturally discharged from the refrigerant ring system during warm-up operation.

2. Description of the Related Art Various boiling cooling devices that utilize a cycle of boiling and condensing a refrigerant have been proposed as cooling devices for automobile engines and the like. The biggest problem in this type of cooling system is how to remove air, which is a non-condensable gas, from the system and prevent its intrusion.

For example, the device described in Japanese Patent Publication No. 47-5019 is
As shown in Fig. 2, a condenser 32 is installed upright on the upper wall of the water jacket 31, and the generated steam rising from the water jacket 31 naturally flows into the condenser 32I, and the condensed liquid phase refrigerant flows into the mother water. Although the jacket 31ζ is configured to drip, the condenser upper tank 33 and the external refrigerant container 34 are always in communication through the refrigerant passage 35. That is, the air remaining in the system is naturally discharged through the refrigerant passage 35, and as the internal pressure rises and the liquid phase refrigerant is pushed out from the condenser 32 to the refrigerant container 34, the condenser 32 is Formation of a steaming space in the upper part that does not contain air.

However, in such a configuration, there is a risk that the vapor flow rising from below the condenser 32 may push out the liquid droplets condensed inside the condenser 32 to the outside of the condenser 32. The amount of refrigerant and the amount of heat dissipated by the condenser 32 are extremely unstable, and therefore it cannot be applied to automobile engines that require high output and stable cooling.

In response to this, the present applicant has formed a closed-loop refrigerant circulation system mainly consisting of a water jacket, a condenser, and a refrigerant supply pump, and after guiding the refrigerant vapor generated in the water jacket to the condenser and condensing it, the refrigerant vapor is condensed. Various boiling cooling devices have been proposed in which the refrigerant is resupplied to the water jacket by operating a refrigerant supply pump based on the detection of the surface sensor. In this device, an air exhaust passage equipped with a solenoid valve is connected to the top of the system, and liquid phase refrigerant is forcibly introduced into the system from a reservoir tank outside the system using a refrigerant supply pump immediately after startup. At the same time, the electromagnetic valve described above is used to discharge the remaining 22 gases in the system. (For example, JP-A-60-36712, JP-A-60-36715, etc.).

Problems to be Solved by the Invention However, in the method described above in which air is forced out by forced introduction of refrigerant using a refrigerant supply pump, multiple solenoid valves serving as flow path switching mechanisms are required before and after the refrigerant supply pump. In addition, complicated control including the tm valve of the air exhaust passage must be performed, making it difficult to simplify the device and reduce costs.

Means for Solving the Problems In order to solve the above problems, the present invention provides a reservoir tank that is open to the atmosphere outside the closed refrigerant circulation system, and connects the lower part of the reservoir tank and the refrigerant outlet of the lower tank. In order to further simplify the configuration, the refrigerant supply pump is linked to the liquid level switch, and the cooling fan is linked to the temperature switch of the lower tank. The configuration is as follows.

Function During normal operation, the refrigerant in the system is circulated, repeating the cycle of boiling and vaporizing in the water jacket and condensing in the condenser. Here, the refrigerant supply pump is turned on and off in conjunction with the liquid level switch to maintain the refrigerant liquid level in the water jacket at a predetermined level. Further, the cooling fan operates when the temperature of the refrigerant in the lower tank reaches a predetermined temperature t, and forcibly cools the condenser.

On the other hand, if air were to enter the system where the refrigerant boils and condenses as described above for some reason, the air would be naturally collected in the lower part of the condenser by the steam flow, and from there it would flow into the auxiliary refrigerant passage. It is expelled from the system as steam through the Since the refrigerant outlet of the lower tank is located below the connection part of the auxiliary refrigerant passage, the refrigerant supply pump does not suck in air.

In addition, after the engine is stopped, the reservoir tank and lower tank are always in communication, so as the temperature or pressure in the system drops, liquid phase refrigerant flows from the reservoir tank into the system, and eventually the entire system is It is filled with liquid phase refrigerant to prevent air from entering.

After startup, boiling begins within the water jacket, and as a result, liquid phase refrigerant is naturally pushed out from the system into the reservoir tank, securing the necessary vapor space in the upper part of the system.

Embodiment FIG. 1 shows an embodiment of the evaporative cooling device according to the present invention, in which 1 is an internal combustion engine equipped with a walk jacket 2, 3 is a condenser for condensing a gas phase refrigerant, Reference numeral 4 indicates an electric refrigerant supply pump.

The water jacket 2 is formed by both the cylinder block 5 and the cylinder head 60 (the upper part, which is normally a gas phase space), so as to surround the outer periphery of the cylinder and combustion chamber of the inner engine 1. Each cylinder communicates with each other, and a steam lower is provided at an appropriate position above the cylinder.This steam lower is connected to the upper part 3a of the condenser 3 via a connecting pipe 8 and a steam passage 9. The connecting pipe 8 is formed with a refrigerant injection part 8a, which is the uppermost part of the refrigerant circulation system, in an upwardly erected shape, and the upper opening thereof is sealed by a cap 10.

Further, a liquid level switch 11 is disposed at a predetermined level of the water jacket 2, specifically at a height f approximately in the middle of the cylinder head 6 side, and is operated to open and close depending on the presence or absence of liquid phase refrigerant. '+1 is connected to the source EC via this liquid level switch 11.

In addition, 12 is a heater passage 1 in the water jacket 2.
A heater core for heating the passenger compartment 14 is connected through a heater core 3, and a heater pump 15 that operates in conjunction with a heater switch (not shown) is provided downstream of the heater core.

The capacitor 3 is connected to the upper tank 1 having the population 3a described above.
6, a core part 17 mainly composed of fine 1,000-tubes along the vertical direction, and a lower tank 18 that temporarily stores the liquid phase refrigerant condensed in this core part 17. A cooling fan 19 for forced cooling is installed on the curved surface or back side of the cooling fan 19, which receives wind from the vehicle running. This cooling fan 19
is connected to a power source via a temperature switch 20 disposed in the lower tank 18, and is configured to operate when the temperature is higher than a predetermined temperature. The operating temperature of the temperature switch 20 is a temperature slightly lower than the boiling point of the refrigerant at high altitudes, for example, 83°C.
It is set to a certain degree.

Further, one end of a refrigerant circulation passage 21 is connected to the refrigerant outlet 181L at the bottom of the lower tank 18, and the other end of this refrigerant circulation passage 21 is connected to the refrigerant population 2a provided on the cylinder block 5 side of the water jacket 2. It is connected to the. In the middle part of the refrigerant circulation passage 21,
The refrigerant supply pump 4 described above is interposed. 22 is a refrigerant mixing passage that communicates the lower tank 8 with the water jacket 2, and the cross-sectional area of the passage is set so that a relatively small amount of liquid phase refrigerant flows from the water jacket 2 to the lower tank 18.

Above water jacket 2. The condenser 3 degree refrigerant circulation passage 21 and the refrigerant supply pump 4 constitute a refrigerant circulation system in which the refrigerant circulates while repeating a cycle of boiling and condensation. The imperial edict indicates a reservoir tank provided outside the refrigerant circulation system, which is open to the atmosphere through a cap 24 having a ventilation function. installed at the same height. One end of the auxiliary refrigerant passage 25 is connected to the bottom of the reservoir tank 23, and the other end is connected above the refrigerant outlet 18a of the lower tank 18.

Next, the operation of the evaporative cooling system constructed as described above will be explained.

First, when the engine is stopped, the entire refrigerant circulation system is filled with liquid phase refrigerant (eg, ethylene glycol aqueous solution), and some liquid phase refrigerant remains in the reservoir tank 23. When the engine is started in this state, since the refrigerant in the water jacket 2 is in an uradome state, its temperature quickly rises and eventually begins to boil.

When boiling begins, the pressure in the system increases due to the generated vapor pressure, and excess refrigerant is gradually pushed out from the lower tank 18 of the condenser 3 to the reservoir tank 23, causing vapor phase refrigerant to flow into the upper part of the water jacket 2 and the upper part of the condenser 3. When the refrigerant liquid level in the water jacket 2 falls below the level of the liquid level switch 110, the refrigerant supply pump 4 is turned on in conjunction with the liquid level switch ttt, and the refrigerant supply pump 4 is turned ON in conjunction with the liquid level switch ttt. As a result, the liquid level of the refrigerant in the water jacket 2 is always maintained near a predetermined level.

In addition, as the vapor phase refrigerant range expands above the condenser 3, the heat dissipation capacity of the condenser 3 increases, so the liquid level position of the condenser 3 is determined at a position where this heat dissipation capacity and the engine heat generation amount are balanced, and from then on the engine The liquid level in the capacitor 3 naturally moves up and down depending on the load on the system, the wind in which the vehicle is running, etc., while keeping the temperature within the system substantially constant. The cooling fan 19 is connected to the lower tank 1
When the temperature of the refrigerant in 8 rises, it starts operating and forcibly cools the condenser 3.

The maximum heat dissipation capacity of the condenser 3 is set so as not to lower the engine heat generation value, so even if the lower tough 18 and the reservoir tank 23 are in constant communication, steam will not leak out. Within the system? If air, which is a non-condensable gas, enters, the heat dissipation ability of the condenser 3 may be reduced. In this case, air is pushed by the refrigerant vapor and tends to stay below the condenser 3, so when the refrigerant liquid level in the condenser 3 drops due to a decrease in the heat dissipation capacity of the condenser 3, it passes through the auxiliary refrigerant passage 25. It is pushed out to the reservoir tank 23, that is, it is naturally discharged.

Note that some refrigerant vapor flows out along with the air.

This condenses in the reservoir tank 23 and is recovered.

Furthermore, since the refrigerant outlet 18a of the lower tank 18 is located below the connection part of the auxiliary refrigerant passage 25, there is no risk of air being sucked into the refrigerant supply pump 4.

If boiling and condensation of the refrigerant as described above is repeated in the refrigerant circulation system, since the refrigerant condensed in the condenser 3 is almost pure water, there is a risk of uneven distribution of antifreeze components in the system. However, in the above embodiment, the refrigerant mixing passage 2
Since an appropriate amount of liquid phase refrigerant is returned from the water jacket 2 to the lower tank 18 via the water jacket 2, the antifreeze components can be made uniform, and fluctuations in the boiling point due to uneven distribution of the antifreeze components can be prevented.

In addition, after the engine stops, the liquid phase refrigerant moves from the reservoir tank n into the system as the pressure decreases due to the temperature drop in the system.
Eventually, the entire system is filled with liquid phase refrigerant, preventing air from entering during the stoppage. As described above, since the antifreeze components are prevented from being unevenly distributed, the condenser 3 and the like do not freeze even in very cold regions.

Effects of the Invention As is clear from the above explanation, according to the boiling cooling device for an internal combustion engine according to the present invention, air that has entered the system for some reason can be automatically discharged, and the refrigerant supply pump can forcefully discharge the air that has entered the system for some reason. There is no need for numerous solenoid valves or complicated controls, which are required when discharging air.

Since the refrigerant supply pump and cooling fan are simply linked to the liquid level switch and temperature switch, the cooling system uses the boiling and condensing cycle of the refrigerant with an extremely simple configuration that does not require complicated control circuits. Cooling with excellent efficiency and temperature uniformity can be achieved.

[Brief explanation of drawings]

FIG. 1 is a structural explanatory diagram showing one embodiment of the present invention, and FIG. 2 is a structural explanatory diagram showing an example of a conventional evaporative cooling device. 1... Internal combustion engine, 2... Water jacket, 3...
...Condenser, 4...Refrigerant supply pump, 11...
Liquid level switch, 18... Lower tank, 18a... Refrigerant outlet, 19... Cooling fan, 20... Temperature switch, 22... Refrigerant mixing passage, 23... Reservoir tank, 25... ...Auxiliary refrigerant passage.

Claims (1)

[Claims] (1) A water jacket in which liquid refrigerant is stored up to a predetermined level determined by a liquid level switch, the refrigerant vapor generated in this water jacket is introduced, and the condensed liquid refrigerant is stored in the lower tank at the bottom. Consisting of a condenser, a refrigerant supply pump that operates in conjunction with the liquid level switch and replenishes the water jacket with liquid phase refrigerant taken out from the refrigerant outlet at the bottom of the lower tank, the water jacket, the condenser, and the refrigerant supply pump. A reservoir tank that is open to the atmosphere and is provided outside the sealed refrigerant circulation system, and an auxiliary refrigerant passage that has one end connected to the lower part of the reservoir tank and the other end connected to the upper part of the refrigerant outlet of the lower tank. and a cooling fan installed next to the condenser and operated in conjunction with a temperature switch provided in the lower tank.