JPS6287606A - Evaporative cooling device - Google Patents

Abstract

PURPOSE:To prevent an engine from being overheated by providing a refrigerant mixing means mixing the liquid refrigerant in a water jacket with the condenser side and a temperature detector detecting the refrigerant temperature in the water jacket. CONSTITUTION:An evaporative cooling device is mainly constituted of a water jacket 2, a condenser 3, a refrigerant feed pump,and a reservoir tank 21. A refrigerant mixing means is mainly constituted of a heater pump 30 and a refrigerant mixing passage 31 to mix the liquid refrigerant in the water jacket 2 with the condenser 3 side. A temperature detector 34 is arranged in the water jacket 2, and the refrigerant mixing means is operated when the cooling temperature in the water jacket 2 becomes higher than the predetermined boiling point. Accordingly, an engine can be reliably prevented from being overheated, and the condenser, refrigerant feed pump, etc. can be prevented. from being frozen in winter.

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 an improvement in a boiling cooling device in which the system pressure is maintained at approximately atmospheric pressure via a reservoir tank opened to the atmosphere.

Prior Art The present applicant 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 liquid level sensor We have proposed a boiling cooling system in which the refrigerant is resupplied to the water jacket by operating a refrigerant supply pump based on the detection of refrigerant (
For example, JP-A-60-36712, JP-A-60-3
6715, etc.). In this system, the refrigerant circulation system is kept in a closed state, and the temperature inside the system is maintained at a desired temperature by controlling a cooling fan based on, for example, a temperature sensor.

On the other hand, the present applicant has also proposed a boiling cooling device that is open to the atmosphere and is extremely simplified without performing complicated temperature control (Japanese Patent Application No. 147814/1984, etc.). This system keeps the reservoir tank and condenser lower tank, which are open to the atmosphere, in continuous communication, and maintains the system consisting of the condenser, water jacket, etc. at approximately atmospheric pressure. Since the refrigerant can move freely, the temperature within the system can be kept approximately constant while the liquid level within the condenser naturally moves up and down so that the amount of heat dissipated by the condenser and the amount of heat generated by the engine are in balance.

Problems to be Solved by the Invention Incidentally, as a refrigerant in this type of boiling cooling device, it is possible to use a mixture of water with an antifreeze such as two-handed gelatin glycol or propylene glycol, and a small amount of a rust preventive agent. For example, since an aqueous solution of ethylene glycol is a non-azeotropic mixture, the vapor of the aqueous solution contains almost no ethylene glycol and is mostly water vapor. For example, the vapor of a 504 aqueous solution of two-handed Astragalus contains only about two parts of Astragalus.

Therefore, when an engine equipped with the above-mentioned evaporative cooling device is operated continuously, a large amount of ethylene glycol is unevenly distributed in the water jacket, and the concentration of two-handed ethylene glycol becomes extremely small on the condenser side. Therefore, in the above-mentioned atmospheric cooling system, there is a risk that the boiling point of the refrigerant will rise due to an increase in the ethylene glycol concentration in the water jacket, causing the engine temperature to become excessively high. Freezing may occur inside the condenser or in the refrigerant supply pump.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a refrigerant mixing means for mixing the liquid phase refrigerant in the water jacket to the condenser side, and a temperature detection device in the water jacket. The refrigerant mixing means is characterized in that the refrigerant mixing means is configured to operate when the temperature of the refrigerant in the water jacket becomes higher than a predetermined boiling point.

As a result of the boiling of the refrigerant, the concentration of ethylene glycol, which is an antifreeze component in the working refrigerant, increases on the water jacket side and decreases on the condenser side, as described above. Since the pressure inside the water jacket and the like is maintained at approximately atmospheric pressure via the reservoir tank, the boiling point of the refrigerant increases as the concentration within the water jacket increases.

Therefore, if a large concentration change occurs due to long-term operation, the temperature of the refrigerant in the water jacket exceeds a predetermined operating temperature, and the refrigerant mixing means is activated. As a result, a part of the liquid phase refrigerant in the water jacket is mixed into the condenser side, and the refrigerants on both sides are homogenized.

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 water jacket 2, 3 is a condenser for condensing a vapor phase refrigerant, Reference numeral 4 indicates an electric refrigerant supply pump.

The water jacket 2 is formed over both the cylinder block 5 and the cylinder head 6 so as to surround the cylinder and the outer periphery of the combustion chamber of the inner/twisting machine IS&l 1, and the upper part, which is normally a gas phase space. are in communication with each other in each cylinder, and a plurality of steam volume lowers are provided at appropriate positions above the cylinders. This steam volume lower is
They are brought together by a steam manifold 8 having a gas-liquid separation function, and communicated with the upper part 3a of the condenser 3 via a steam passage 9. Reference numeral 10 indicates a refrigerant recovery passageway for returning the liquid-phase refrigerant captured by gas-liquid separation to the water jacket 2. Reference numeral 11 indicates an air introduction passageway equipped with a normally closed solenoid valve 12, and the solenoid valve 12 has a temperature of 50° C. or lower, for example. O when
It is connected to a power source via a first temperature change switch 13 which is operated at N. A liquid level switch 14 that opens and closes depending on the presence or absence of liquid phase refrigerant is disposed at a predetermined level of the water jacket 2, specifically at a height position approximately in the middle on the cylinder head 6 side, and a refrigerant supply pump is installed. 4 is connected to a power source via this liquid level switch 14.

The capacitor 3 is connected to the upper tank 1 having the population 3a described above.
5, a core part 16 mainly consisting of fine tubes along the vertical direction, and a lower tank 17 that temporarily stores the liquid phase refrigerant condensed in this core part 16. The cooling fan 18 is installed in a position where it can catch wind from the vehicle running, and an electric cooling fan 18 for forced cooling is installed on the front or back side of the fan. This cooling fan 18 is directly connected to the source via a second temperature switch 19 disposed in the lower tank 17, and when the degree of supercooling of the liquid phase refrigerant in the lower tank 17 becomes small, the refrigerant temperature reaches 95°C, for example. It is configured to operate when the above conditions occur.

Reference numeral 21 denotes a reservoir tank disposed at a height approximately equal to the set level of the liquid level switch 14, and is connected to the lower tank 17 via the first refrigerant circulation passage 22, and is connected to the lower tank 17 via the refrigerant supply pump 4. It is connected to the water jacket 2 through a second refrigerant circulation passage provided therein. A pressure regulating valve 25 is provided in the atmospheric communication passage 24 connected to the upper space to maintain the internal pressure at 7501a4Hgf even at high altitudes, and a refrigerant inlet cap 26 is installed to maintain the internal pressure at 7501a4Hgf when the inside of the tank is under negative pressure. A one-way valve that opens is closed inside.

Reference numeral 27 denotes a heater core for heating the vehicle compartment 29, which is connected to the water jacket 2 through a heater passage 28, and a heater pump 30 is interposed on the downstream side of the heater core. Road heater pump 3
A refrigerant mixing passage 31 is branched from the zero discharge side, and its tip is connected to the upstream portion of the steam passage 9. That is, in this embodiment, the refrigerant mixing means is mainly composed of the heater pump 30 and the refrigerant mixing passage 31. The heater pump 30 is connected to a power source via an ignition switch 32 and a heater switch 33, and is also connected to a power source via a third temperature switch in parallel thereto. The third temperature switch 34 is composed of, for example, a bimetallic switch that is turned ON at high temperatures, and is used to control the liquid phase refrigerant, which has a specific axially low temperature, and which flows from the second refrigerant circulation passage 23 at a relatively lower part of the water jacket 2. For example, if a 50% aqueous solution of two-handed ranger liquor is used as the refrigerant, its operating temperature will exceed its boiling point (approximately 110°C) at normal pressure to some extent115. It is set around ℃.

Next, the operation of the evaporative cooling device configured as described above will be explained.

First, when the engine is in a stopped state, the inside of the water jacket 2 and condenser 3 are filled with liquid phase refrigerant (for example, a 50% aqueous solution of two-hand ranger recall), and some liquid phase refrigerant is in the reservoir tank 21. remains. When the engine is started in this state, the first temperature switch 13 is in the ON state except for a warm-up restart, so the solenoid valve 12 opens and the refrigerant liquid level in the water jacket 2 rises to
The liquid level of the refrigerant decreases to be equal to the liquid level of the refrigerant in the tank 21.

Specifically, the refrigerant liquid level drops to near the set level of the liquid level switch 14, and rapid warm-up is performed.

As the warm-up progresses, the solenoid valve 12 closes, and then the refrigerant begins to boil. At this time, the air remaining inside the water jacket 2 is pushed by the generated steam and is collected below the condenser 3, and is further collected in the first refrigerant circulation passage 22.
It is pushed out to the reservoir tank 21 through the tank. Further, when the refrigerant liquid level in the water jacket 2 drops by one level below the set level of the liquid level switch 14 due to boiling, the refrigerant supply pump 4 is activated to supply liquid phase refrigerant from the reservoir tank 21 to the water jacket 2. That is, the refrigerant supply pop 4 operates intermittently in conjunction with the liquid level switch 14 to keep the refrigerant liquid level in the water jacket 2 constant. In this embodiment, the liquid phase refrigerant condensed in the condenser 3 is returned to the water jacket 2 via the reservoir tank 21, but it is supplied to the direct seeded water jacket 2 from the lower tank 17 of the condenser 3. It may also be used as a configuration.

Further, since the vapor phase refrigerant region is expanded 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. The engine temperature is kept approximately constant while the liquid level of the con-an f3 naturally moves up and down depending on the load between the six tabs and the wind in which the vehicle is running. Specifically, the boiling point of the ethylene glycol 50 aqueous solution is maintained at around 110°C. Incidentally, when the liquid level drops to a certain level and the supercooling temperature becomes small, the cooling fan 18 is activated in conjunction with the second temperature switch 19, and the cooling fan 18 is operated in conjunction with the second temperature switch 19. 3 is forcibly cooled.

In this way, cooling is performed using the boiling and condensing cycle of the refrigerant, but as mentioned above, if the operation continues for a long time, the ethylene glycol concentration in the liquid phase refrigerant in the water jacket 2 increases, and the boiling point of the refrigerant increases. gradually increases. When the temperature reaches 115°C, the heater pump 30 is activated in conjunction with the third temperature switch, and a part of the liquid phase refrigerant circulating between the water jacket 2 and the heater core 27 is transferred to the refrigerant mixing passage. 31 and steam passage 9
It mixes into the contan 4)-3 side through the. Therefore, the ethylene glycol concentration is equalized between the water jacket 2 side and the content 9-3 side, and the refrigerant boiling point is lowered again.

In this embodiment, when the heater switch 33 is turned on during winter, the heater pump 30 is activated, and a small amount of liquid phase refrigerant is always pumped from the water jacket 2 to the content 9-.
It is designed to be sent to the third side.

Next, FIG. 2 shows a different embodiment of the invention. In this embodiment, a refrigerant supply pump 4 is used as the refrigerant mixing means.
The liquid phase refrigerant in the water jacket 2 is caused to overflow from the vapor volume lower, thereby flowing into the condenser 3.

Specifically, the refrigerant supply pump 4 is connected to a vL source via a liquid level switch 14, and is connected to a power source via a third temperature switch 34 in parallel thereto.

Therefore, when the boiling point of the refrigerant in the water jacket 2 reaches 115°C due to an increase in ethylene glycol by 11 degrees, the refrigerant supply pump 4 operates independently of the liquid level switch 14, and as a result, the temperature in the water jacket 2 gradually increases. The liquid level of the refrigerant increases, and eventually the liquid phase refrigerant overflows from the vapor volume lower and flows into the condenser 3.

Effects of the Invention As is clear from the above explanation, in the boiling cooling device for an internal combustion engine according to the present invention, the uneven distribution of antifreeze components in the refrigerant can always be suppressed within a certain range, and the increase in the boiling point of the refrigerant It is possible to reliably prevent the engine from overheating.ζ
This can prevent condensers, refrigerant supply pumps, etc. from freezing during the winter.

[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 another embodiment of the present invention. 1. Internal combustion engine, 2. Water jacket, 3. Condenser, 4. Refrigerant supply pump, 14. Liquid level switch,
17. Lower tank, 21. Reservoir tank, 27.
・Heater core, 30.. Heater pump, 31.. Refrigerant mixing passage, 34. 3rd temperature switch.

Claims (1)

[Claims] (1) A water jacket in which a liquid phase refrigerant such as an aqueous ethylene glycol solution is stored up to a predetermined level, and a condenser into which the refrigerant vapor generated in this water jacket is introduced and the condensed liquid phase refrigerant is stored in a lower tank at the bottom. an internal combustion engine comprising: a refrigerant supply pump that replenishes the water jacket with liquid phase refrigerant condensed in the condenser; and a reservoir tank that is constantly in communication with the lower tank and whose internal pressure is maintained at approximately atmospheric pressure. In the boiling cooling device, a refrigerant mixing means is provided to mix the liquid phase refrigerant in the water jacket to the condenser side, and a temperature detector is provided in the water jacket so that the temperature of the refrigerant in the water jacket reaches a predetermined boiling point. 1. A boiling cooling device for an internal combustion engine, characterized in that the refrigerant mixing means is configured to operate when the temperature reaches a higher temperature.