US-12624870-B2 - Cooling device

Abstract

This cooling device is equipped with a tank, a pump, an evaporator, and a condenser. The gas phase portion of the tank is filled with a filler gas and is equipped with a volume-changing unit. The volume-changing unit is configured to adjust an evaporation temperature of the refrigerant by changing a pressure of the refrigerant, which is achieved by changing a volume of the gas phase portion to change a pressure of the filler gas.

Inventors

• Shunsuke SEKIMOTO

Assignees

• SHIMADZU CORPORATION

Dates

Publication Date

20260512

Application Date

20220627

Priority Date

20211029

Claims (8)

1. 1 . A cooling device comprising: a tank configured to store a liquid refrigerant; a pump configured to discharge the liquid refrigerant stored in the tank; an evaporator configured to cool a cooling target by evaporating the liquid refrigerant discharged from the pump; and a condenser configured to condense a gaseous refrigerant generated by the refrigerant evaporated by the evaporator, wherein a gas phase portion of the tank is filled with a filler gas and is equipped with a volume-changing unit, the volume-changing unit being configured to adjust an evaporation temperature of the refrigerant by changing a pressure of the refrigerant, which is achieved by changing a volume of the gas phase portion to change a pressure of the filler gas.
2. 2 . The cooling device as recited in claim 1 , wherein the volume-changing unit is configured to change the volume of the gas phase portion by changing a volume of the volume-changing unit by being expanded and contracted by a volume-changing gas.
3. 3 . The cooling device as recited in claim 2 , wherein the volume-changing unit is configured to change the volume of the gas phase portion so that the volume of the gas phase portion reduces by the volume-changing unit being deformed to stretch and increase in volume when the volume-changing gas is supplied into an interior of the volume-changing unit from a gas source, and change the volume of the gas phase portion so that the volume of the gas phase portion increases by the-volume changing unit being deformed to contract and decrease in volume when the volume-changing gas is discharged from the interior of the volume-changing unit to an exterior of the volume-changing unit.
4. 4 . The cooling device as recited in claim 2 , wherein the volume-changing unit is configured to adjust the evaporation temperature of the refrigerant by changing the volume of the gas phase portion, which is achieved by changing the volume of the volume-changing unit by the volume-changing gas so that a temperature of the evaporator or a temperature of the refrigerant in the evaporator reaches a target temperature.
5. 5 . The cooling device as recited in claim 1 , wherein the volume-changing unit is a metal bellows.
6. 6 . The cooling device as recited in claim 1 , wherein the filler gas is an inert gas that neither reacts with the refrigerant nor condenses due to volume changes of the gas phase portion by the volume-changing unit.
7. 7 . The cooling device as recited in claim 6 , wherein the filler gas includes at least one of nitrogen and argon.
8. 8 . The cooling device as recited in claim 1 , wherein the volume-changing unit is mounted on a ceiling of the tank.

Description

TECHNICAL FIELD The present invention relates to a cooling device. BACKGROUND ART Conventionally, a cooling device equipped with an evaporator and a condenser has been disclosed. Such a cooling device is disclosed, for example, in Terushige FUJII, and three others, a “Research on Temperature Control by Steam Valve Operation of a Fluid Loop Type Exhaust Heat System Using Latent Heat,” a JAXA Contract Report, Japan Aerospace Exploration Agency, Oct. 29, 2004, JAXA-CR-04-002 (hereinafter simply referred to as “Non-Patent Document 1”). The above Non-Patent Document 1 discloses a cooling device equipped with a pump, an evaporator, a condenser, and a valve. In the above Non-Patent Document 1, the refrigerant supplied from the pump evaporates by absorbing the thermal load in the evaporator and condenses in the condenser. Further, the condensed refrigerant returns to the pump and is sent out again to repeat the circulation. Further, in the above-described Non-Patent Document 1, a valve is provided between the evaporator and the condenser, and it changes the pressure of the refrigerant inside the evaporator and the evaporation temperature of the refrigerant by changing its opening degree. Further, in the above-described Non-Patent Document 1, the temperature at the surface of the evaporator (i.e., the cooling temperature) is adjusted by adjusting the evaporation temperature of the refrigerant by operating the valve opening between the evaporator and the condenser. PRIOR ART DOCUMENT Patent Document Non-Patent Document 1: Terushige FUJII, and other three persons, “Study on Temperature Control by Steam Valve Operation of a Fluid Loop Type Heat Exhaust System Using Latent Heat,” a JAXA Contract Report, Japan Aerospace Exploration Agency, Oct. 29, 2004, JAXA-CR-04-002 SUMMARY OF THE INVENTION Problems to be Solved by the Invention However, in the cooling device described in the above Non-Patent Document 1, since the evaporation temperature of the refrigerant is adjusted by operating the valve opening between the evaporator and the condenser, there is an inconvenience that the pressure boost amount (pressure increase amount) of the refrigerant by the pump becomes large due to the pressure loss at the valve. In this case, the pump become larger, making it impossible to adjust the cooling temperature while reducing the size of the pump. This present invention has been made to solve the above problems. One object of the present invention is to provide a cooling device capable of adjusting the cooling temperature in two-phase cooling using the phase change when the refrigerant changes from liquid to gas while reducing the size of the pump. Means for Solving the Problems In order to attain the above objects, a cooling device according to one aspect of the present invention, comprises a tank configured to store a liquid refrigerant;a pump configured to discharge the liquid refrigerant stored in the tank;an evaporator configured to cool a cooling target by evaporating the liquid refrigerant discharged from the pump; anda condenser configured to condense a gaseous refrigerant generated by the refrigerant evaporated by the evaporator,wherein a gas phase portion of the tank is filled with a filler gas and is equipped with a volume-changing unit, the volume-changing unit being configured to adjust an evaporation temperature of the refrigerant by changing a pressure of the refrigerant, which is achieved by changing a volume of the gas phase portion to change a pressure of the filler gas. Effects of the Invention In the cooling device according to the above-described one aspect of the present invention, the gas phase portion of the tank is filled with a filler gas. This allows the pressure of the refrigerant to be increased by the pressure (partial pressure) of the filler gas in the gas phase portion of the tank, so the pressure boost amount (pressure increase amount) of the refrigerant by the pump can be reduced by the pressure (partial pressure) of the filler gas. As a result, the pump can be made smaller. Further, a volume-changing unit is equipped with the gas phase portion of the tank, the volume-changing unit being configured to adjust an evaporation temperature of the refrigerant by changing a pressure of the refrigerant, which is achieved by changing a volume of the gas phase portion to change a pressure of the filler gas. With this, it becomes possible to adjust the cooling temperature by adjusting the evaporation temperature of the refrigerant by the volume-changing unit and the filler gas. As a result, in two-phase cooling using the phase change when the refrigerant changes from liquid to gas, the cooling temperature can be regulated while downsizing the pump. Note that in the case of using a refrigerant (such as carbon dioxide) with a large increase rate of the saturation pressure relative to the temperature increase, the pressure boost amount of the refrigerant by the pump tends to become larger. For this reason, this co