JPH0324824Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a boiling cooling device for an internal combustion engine that utilizes the latent heat of vaporization of a refrigerant.

(Prior Art) A water-cooled cooling system that circulates cooling water between an engine water jacket and a radiator is difficult to satisfy the required amount of heat radiation due to efficiency and dimensional limitations of the radiator and heat capacity of water. It is necessary to circulate a large amount of cooling water, which causes a large drive loss in the water pump, and it is difficult to control the cooling water to an appropriate temperature in a responsive manner according to engine operating conditions.

Therefore, a cooling device has been proposed that uses the latent heat of vaporization of the cooling water to cool the engine with a small amount of circulating water. This system performs cooling using a cycle in which the cooling water (liquid phase refrigerant) stored in the water jacket is boiled using the heat generated by the engine, and the generated steam is condensed and liquefied in a radiator (condenser) and returned to the water jacket. It is.
(Utility Model Publication No. 57-18714, Japanese Patent Application Publication No. 59-180023).

(Problems to be solved by the invention) By the way, in this boiling cooling device, since the engine is efficiently cooled with a small amount of refrigerant, it is possible to sufficiently reduce the driving loss of the supply pump that circulates the refrigerant. The steam generated in the water jacket is only radiated to the outside air through a condenser.

Therefore, when the engine is under high load, a large amount of steam is generated, but the energy of the generated steam is not utilized, and there is still room for improvement.

(Means for solving the problem) This idea connects the engine water jacket, which is mostly filled with liquid-phase refrigerant, and the condenser, which maintains the interior in the vapor phase, to the vapor passage through which the refrigerant vapor flows in the upper part, and the condenser. In the boiling cooling device for an internal combustion engine, the boiling cooling device for an internal combustion engine is provided with a cooling fan that communicates with a refrigerant passage through which liquefied refrigerant is returned via a supply pump to form a closed circuit in which the refrigerant circulates, and supplies forced cooling air to the condenser. An expander operated by refrigerant vapor is installed in the middle of the steam passage, and the cooling fan is driven by this expander.

Further, in this invention, a superheater is provided which is located upstream of the expander and supplies exhaust heat from the internal combustion engine to refrigerant vapor.

(Function) Therefore, the energy of the steam generated in the water jacket and the engine exhaust energy can be effectively utilized to reliably reduce the driving loss of the cooling fan.

(Embodiment) Fig. 1 shows an embodiment of the boiling cooling device according to this invention, in which 1 is an engine (main body), 2 is a water jacket filled mostly with liquid-phase refrigerant such as water, and 3 4 is a condenser that cools and liquefies the refrigerant vapor from water jacket 2, and 4 is a condenser 3.
5 is a supply pump that returns the refrigerant stored in the lower tank 4 to the water jacket 2, and 6 is a cooling fan that supplies forced cooling air to the condenser 3.

The water jacket 2 is attached to the cylinder block 1 so as to surround the cylinders and combustion chambers of the engine 1.
a and cylinder head 1b, and a predetermined amount of liquid phase refrigerant is sealed inside.
The upper part of the water jacket 2 is a gas phase space filled with refrigerant vapor, and in a multi-cylinder engine, the gas phase space is communicated with each other between cylinder sections.

A steam passage 7 is connected to the water jacket 2 facing the gas phase space, and communicates with the inlet portion of the condenser 3 via the steam passage 7.

In the case of a car, the condenser 3 is installed in a position where the wind flows through the vehicle, and the lower tank 4 communicates with the water jacket 2 through a refrigerant passage 8, forming a closed circuit in which refrigerant circulates between the water jacket 2 and the condenser 3. form.

The cooling fan 6 is installed on the front or back side of the condenser 3 and is driven by an expander 9.

The expander 9 is a type of motor operated by steam, such as the one shown in FIG. 2, for example.

This has almost the same structure as a vane-type pneumatic motor, and the vanes 11 are pushed in one direction by steam flowing in from the inlet 10, causing the rotor 12 to rotate.

The expander 9 has an inlet 10 and an outlet 13
The cooling fan 6 is connected to the rotating shaft 14 of the rotor 12 .

In this case, the steam passage 7 is formed so as to fall down from the water jacket 2 and the condenser 3 depending on the position of the expander 9. Further, the expander 9 is provided with a drain port (not shown) for discharging the refrigerant liquefied inside.
It is connected to the lower tank 4 via 5.

Note that the expander 9 may be gear-shaped or steam turbine-shaped. A superheater 17 is interposed in the middle of the steam passage 7 so as to be located upstream of the expander 9.

As shown in FIG. 3, the superheater 17 has a pipe 19 coiled inside a casing 18, a steam passage 7 is connected to the pipe 19, and the casing 18 is connected to an exhaust pipe 20 of the engine 1. The engine exhaust gas is allowed to pass through the casing 18. In this way, by heating the refrigerant vapor with the exhaust heat of the engine 1, the expander 9
This greatly increases the amount of heat energy flowing into the

On the other hand, a liquid level sensor 16 is installed in the water jacket 2 at a position where the internal refrigerant liquid level is at an appropriate level.

The liquid level sensor 16 is a switch that turns on and off depending on the position of the refrigerant liquid level with respect to the detection part, and when the refrigerant liquid level falls below the detection part, the supply pump 5 of the refrigerant passage 8 is driven by a control circuit (not shown). , replenish the water jacket 2 with the refrigerant stored in the lower tank 4.

In such a configuration, when the liquid phase refrigerant in the water jacket 2 is heated by the engine combustion heat, it starts boiling when it reaches a predetermined temperature, absorbs a large amount of latent heat of vaporization, and evaporates.

At this time, the refrigerant boils more actively in the higher temperature parts of the engine 1 and cools down by the amount equivalent to the latent heat of vaporization.
The combustion chamber and cylinder walls are kept at a nearly uniform temperature.

The refrigerant vapor thus generated flows into the expander 9 via the vapor passage 7, and the expander 9 is operated by the energy of the vapor.

As described above, the refrigerant vapor is heated in advance by heat exchange with the engine exhaust gas in the superheater 17 before flowing into the expander 9.

When the amount of refrigerant vapor generated is small, the rotation of the expander 9 is low, but as the amount of generated refrigerant vapor increases, the rotation of the expander 9 increases. Therefore, the cooling fan 6 is rotated less at high loads when the engine generates a large amount of heat. Provide sufficient ventilation.

Then, the refrigerant vapor that has passed through the expander 9 flows into the condenser 3, where it exchanges heat with the outside air by the air blown by the cooling fan 6 and the running air.
It is cooled according to the amount of air and condensed into the original liquid.

At this time, the refrigerant vapor is cooled by the outside air with a large temperature difference with good heat transfer between it and the metal surface of the condenser 3, so higher heat dissipation and condensation action are ensured compared to when heat is dissipated in the liquid phase. Ru.

The refrigerant condensed into liquid is stored in the lower tank 4 and is returned to the water jacket 2 by the supply pump 5 which is activated when the refrigerant level in the water jacket 2 decreases.

In this way, the latent heat of vaporization of the refrigerant is large, and the condenser 3 provides high heat dissipation and condensation, so the engine can be efficiently cooled with a small amount of refrigerant, and the supply pump 5 can therefore be made smaller. This makes it possible to significantly reduce driving loss.

Then, the cooling fan 6 is driven by the refrigerant vapor which has become sufficiently high in temperature through heat exchange with the exhaust gas.
Sufficient cooling air is obtained when the engine needs to be cooled, thereby eliminating the need for driving power for the cooling fan 6 and allowing the engine to be cooled accurately depending on the operating conditions.

Note that by operating the expander 9, the temperature of the refrigerant vapor can be lowered, and since the refrigerant liquefied here flows down from the discharge passage 15 to the lower tank 4, the operation of the expander 9 is always in good condition. It is maintained.

(Effects of the invention) As described above, in the present invention, the cooling fan is driven by the refrigerant vapor generated in the water jacket, so the driving power for the cooling fan is not required, and
The more heat generated by the engine, the more sufficient cooling air is supplied, allowing the engine to be cooled efficiently and accurately.

On the other hand, in this invention, the temperature is increased by superheating the refrigerant vapor supplied to the expander via a superheater, which has the effect of effectively utilizing surplus energy from the engine and improving overall thermal efficiency. You can also get

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIGS. 2 and 3 are sectional views of an expander and a superheater of the embodiment, respectively. 2...Water jacket, 3...Condenser, 5...Supply pump, 6...Cooling fan, 7...
...Steam passage, 8...Refrigerant passage, 9...Expander, 17...Superheater.

Claims (1)

[Scope of utility model registration request] The engine water jacket, which is mostly filled with liquid-phase refrigerant, and the condenser, which maintains the interior in the vapor phase, are connected to a vapor passage through which the refrigerant vapor flows in the upper part, and a refrigerant passage, which returns the liquefied refrigerant from the condenser via a supply pump. to form a closed circuit in which refrigerant circulates,
In a boiling cooling system for an internal combustion engine that is equipped with a cooling fan that supplies forced cooling air to a condenser, a superheater that supplies engine exhaust heat to refrigerant vapor is interposed in the middle of the steam passage, and a 1. A boiling cooling system for an internal combustion engine, characterized in that an expander operated by refrigerant vapor is installed on the side, and the cooling fan is driven by the expander.