JPS5824451Y2 - Jiyo Hatsurei Yakusouchi - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an evaporative cooling device that has good cooling efficiency and does not require a pressure vessel.

For example, evaporative cooling devices are known that circulate refrigerant to cool semiconductor elements for controlling electric vehicles.

However, it has been found from the results of previous research that if a non-condensable gas other than the refrigerant, such as air, gets mixed into the refrigerant circulation system of this type of device, the condensation efficiency of the refrigerant decreases and its circulation is inhibited. This is what we are doing.

For this purpose, a method is generally used in which air is removed from the container and then filled with refrigerant, that is, a vacuum (sealed) pressure container is used.

A specific example of this is shown in FIG.

This device includes a closed container 9, a heating element 3 (semiconductor, etc.), a refrigerant liquid 2, a heat insulating pipe 10, a condenser 4, and an isobaric holding tongue 1.
1. Consisting of

In this device, a refrigerant liquid 2 is vaporized by a heating element 3, and the vapor 12 is liquefied in a condenser 4 through a thermally insulated pipe 10.
Cooling is effected by the circulation that returns to the container 9 through the thermally insulated pipe 10.

The equal pressure maintaining tongue 11 is for suppressing the pressure increase in the system due to the generated steam 12.

The disadvantages of this device are as follows.

(,1) The cooling system must be sealed and made into a vacuum container (pressure-resistant container).

As a result, the equipment becomes more complex, and its value is halved in terms of shape, weight, price, maintenance, and handling.

In particular, it cannot be used in electric vehicles, which require portability, small size, and light weight.

(2) If air (non-condensable gas) is mixed in with this device, make sure that the steam and condensate are in the same passage, that the condenser is vertically above it, and that there is an isobaric tongue above it. Because of this, the generated steam, air, and condensate coexist in the inflow section at the bottom of the condenser, making it impossible to separate air and generated steam, reducing condensing performance, and in some cases, reducing the condensate completely. Experiments have revealed that there are cases in which condensation is not possible.

As an improvement to this, there is a method that does not increase the degree of vacuum, that is, does not require a high pressure vessel, and therefore has a near reservoir with a fixed capacity in consideration of some air leakage.

This is done by initially creating a low vacuum inside the container (inside the circulation system), and over time, the air that enters through pinholes etc. is stored in the near reservoir to prevent the circulation from being obstructed. be.

The disadvantages of this are that even though it is a low vacuum, it is a pressure vessel and does not eliminate all the disadvantages of a pressure vessel, and over a long period of time, the near reservoir fills with air because its volume is always constant. This means that it no longer fulfills its function.

This increases the overall weight of the device and makes it expensive, making it particularly unsuitable for mobile equipment such as cooling control elements of electric vehicles.

This invention is intended to solve the various problems mentioned above, and its purpose is to actively recognize the presence of air in the cooling system and to provide a function to expel that air from the circulation path. The aim was to improve the reliability of the cooling device and make it smaller and lighter.

An embodiment of this invention will be described below with reference to the drawings.

In the figure, 1 is a container for storing a refrigerant 2, such as Freon R-118, and 3 is a heating element to be cooled, which is immersed in the refrigerant 2 in the container 1.

4 is a condenser that exchanges the heat of the vaporized refrigerant with the outside air, water, etc., and liquefies the refrigerant again; the condenser is tilted so that the inflow side of the refrigerant is higher than the outflow side; It is placed above 1.

5 is a steam pipe that communicates the upper part of the container 1 with the refrigerant inlet side of the condenser 4, and 6 is a condensate pipe that communicates the outlet side of the condenser 4 with the lower part of the container 1. A refrigerant circulation system 7 is formed in which refrigerant circulates between the container 1 and the condenser 4 via the steam pipe 5 and the condensate pipe 6.

Further, reference numeral 8 denotes a near reservoir that communicates with the region where the refrigerant vapor pressure is lowest during operation of the condenser 4, that is, the refrigerant outlet side of the lower end of the condenser 4, and is disposed above the liquid level of the container.

This near reservoir 8 is a flexible bag made of an elastic material, and its internal volume increases or decreases according to changes in the pressure within the refrigerant circulation system 7, so that the external pressure and the refrigerant pressure within the circulation system 7 are balanced. .

With this configuration, when the heating element 3 generates heat, heat is exchanged between the heating element 3 and the refrigerant 2 around it, the refrigerant 2 is heated and evaporated, and the heating element 3 is cooled. .

Then, the vaporized refrigerant 2 fills the container 1 and pushes up the non-condensable gas, such as air, inside the container 1, while pushing up the steam pipe 5.
and enters the condenser 4.

It also pushes down the air inside the condenser.

Therefore, the air in the circulation system 7 is forced into the near reservoir 8 by the vapor pressure of the refrigerant 2.

Further, as the pressure within the circulation system 7 increases, the near reservoir 8 expands.

Then, the gas phase refrigerant 2 in the condenser 4 emits its heat to the outside, condenses, becomes liquefied again, and flows down into the container 1 from the condensate pipe 6 due to its own weight.

The pressure distribution inside the condenser 1 is highest on the inflow side, that is, the upper end, and decreases to approximately atmospheric pressure on the outflow side, that is, the lower end, where the gas phase refrigerant is liquefied.

On the other hand, when the operation of the device is stopped, the refrigerant 2 is liquefied and stored in the container 1, and as the pressure in the circulation system 7 decreases, the near reservoir 8 contracts, and the air that was forced there is actively circulated. Fill the system 7 with air.

Therefore, the pressure in the circulation system 7 is maintained at approximately atmospheric pressure.

During operation, the circulation system 7 is filled with the refrigerant 2, and no non-condensable gas is mixed in. Therefore, the condenser 4 can liquefy the gas phase refrigerant 2 with high efficiency, and can also prevent its circulation. There's nothing like being let down.

The volume of the near reservoir 8 increases or decreases depending on the pressure within the circulation system 7, and the internal pressure is maintained at approximately atmospheric pressure, so there is no need for the circulation system 7 to have a special pressure-resistant structure, and thereby,
The weight can be reduced and the structure can be simplified.

Further, since the inside of the circulation system 7 is maintained at approximately atmospheric pressure even during the shutdown, there is no need for a special pressure vessel, and it is possible to prevent external gases such as air from entering the system.

Furthermore, if the inner volume of the near reservoir 8 is made larger than the inner volume of the circulation system 7, even if a gas phase refrigerant that exceeds the condensing capacity of the condenser 4 flows in, the refrigerant 2 that cannot be liquefied will be temporarily stored in the near reservoir 8. can be accommodated.

Therefore, the cooling capacity of the device can be increased and overload operation can be performed for a short time.

Note that this invention is not limited to the above-mentioned embodiments; for example, various fluorocarbon-based refrigerants such as Freon R-112, carbon tetrachloride, trichlene, etc. can also be used as the refrigerant.

In addition, the near reservoir 8 may be of an elastic bellows type, a plastic bag, or a rubber balloon.

Furthermore, in the embodiment described above, the condenser 4 is arranged at an angle and the near reservoir 8 is attached to the lower end thereof, but it is of course not limited to this. The near reservoir 8 may be installed so that it communicates with the lower part.

Further, the condenser 4 may be arranged vertically, or the refrigerant vapor may be introduced from its lower end.

Furthermore, although this invention is suitable for cooling semiconductors for controlling electric vehicles, it can also be applied to various other cooling devices that require small size and light weight.

As detailed above, this idea is to provide a near reservoir in the condenser where the vapor pressure of the refrigerant is lowest, which increases or decreases the internal volume according to the vapor pressure, in a cooler that cools a heating element using a refrigerant. This makes it possible to provide a small, lightweight, and inexpensive evaporative cooling device that has good cooling efficiency and does not require a special pressure vessel.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of this invention, FIG. 2 is a perspective view of the same embodiment, and FIG. 3 is a schematic diagram of an example of a conventional device. 1... Container, 2... Refrigerant, 3...
... Heating element, 4 ... Condenser, 7 ... Circulation system, 8 ... Near reservoir, 9 ... Sealed container, 10 ...・Thermal insulation pipe

Claims (1)

[Scope of utility model registration request] a container for storing a refrigerant and vaporizing the refrigerant to cool the heating element; a condenser arranged at an angle for liquefying the vaporized refrigerant; and a condenser for passing the vaporized refrigerant in the container through a steam pipe to the condenser. and a circulation system that sends the refrigerant liquefied in this condenser to the container through a condensate pipe. An evaporative cooling device comprising a near reservoir whose volume increases or decreases to contain a noncondensable gas and thus maintain the pressure within the system at approximately atmospheric pressure.