Circulating device for two-phase cooling system and method for circulating refrigerant in circulating device for two-phase cooling system

Abstract

This circulation device (100) for a two-phase cooling system is provided with an inlet-side connection section (41) and an outlet-side connection section (42), and a bypass flow path (75) which branches off on the downstream side of a pump (10) and on the upstream side of the inlet-side connection section, and through which a refrigerant flows to a condenser (20) without passing through the inlet-side connection section and the outlet-side connection section, when the evaporator (80) is not connected to the inlet-side connection part and the outlet-side connection part, the refrigerant is circulated through the bypass flow path without passing through the inlet-side connection part and the outlet-side connection part.

Description

Technical Field

[0001] The present invention relates to a circulation device for a two-phase cooling system and a refrigerant circulation method in the circulation device for the two-phase cooling system, and in particular to a circulation device for a two-phase cooling system that circulates refrigerant by connecting a detachable evaporator, a circulation device for a two-phase cooling system and a refrigerant circulation method in the circulation device for the two-phase cooling system. Background Art

[0002] Conventionally, there is known a two-phase cooling system in which a refrigerant circulates by connecting a detachable evaporator to a connection portion. Such a circulation device for a two-phase cooling system is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-179375.

[0003] Japanese Patent Publication No. 2003-179375 discloses a cooling device (two-phase cooling system) which includes a plurality of cooling modules that can be selectively installed in an electronic equipment cabinet. The cooling modules are respectively composed of an evaporative cold plate having an evaporative flow path, a condenser having a condensing flow path, a steam pipeline, and a liquid pipeline. The working fluid flowing in the cooling module flows in the order of the evaporative flow path, the steam pipeline, the condensing flow path, and the liquid pipeline, thereby forming a pressurized two-phase cooling cycle. Japanese Patent Publication No. 2003-179375 discloses the following: It is advantageous to connect the connection portion between the inlet of the evaporative cold plate and the liquid pipeline and the connection portion between the outlet of the evaporative cold plate and the steam pipeline by a detachable connection unit. That is, Japanese Patent Publication No. 2003-179375 discloses a cooling device in which an evaporative cold plate (evaporator) is configured to be detachable relative to a structure including a condenser, a steam pipeline, and a liquid pipeline.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2003-179375 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] In the cooling device of Japanese Patent Application Laid-Open No. 2003-179375, since the working fluid circulates in the evaporative cold plate, the steam line, the condenser, and the liquid line, the working fluid cannot be circulated when the evaporative cold plate is removed from the structure including the condenser, the steam line, and the liquid line. In this case, since the working fluid does not flow into the condenser, when the working fluid is circulated at a temperature much lower than the outside air temperature, the temperature of the working fluid rises due to the heat input based on the temperature outside the cooling device. As a result, soon after the evaporative cold plate is installed again after the evaporative cold plate is removed, the working fluid with the temperature increased circulates, and therefore the cooled working fluid cannot flow into the evaporative cold plate. Therefore, soon after the evaporative cold plate is installed again, the cooling object cannot be immediately cooled by the evaporative cold plate. Therefore, it is desirable that even soon after the evaporative cold plate (evaporator) is reconnected after being removed, the cooled low-temperature working fluid (refrigerant) can flow into the evaporative cold plate (evaporator) and the cooling object can be immediately cooled by the evaporative cold plate (evaporator).

[0009] The present invention is completed to solve the problems as mentioned above. One purpose of the present invention is to provide a circulation device for a two-phase cooling system and a refrigerant circulation method in a circulation device for a two-phase cooling system, which can allow the cooled low-temperature refrigerant to flow into the evaporator even soon after the detachable evaporator is disassembled and then reconnected, and can immediately cool the cooling object through the evaporator.

[0010] Solutions for solving problems

[0011] The first aspect of the present invention is a two-phase cooling system for circulating a refrigerant by connecting a detachable evaporator, and the two-phase cooling system for circulating a refrigerant comprises: a pump for conveying the refrigerant; an inlet-side connection portion and an outlet-side connection portion, the inlet-side connection portion and the outlet-side connection portion being arranged on the downstream side of the pump, the inlet-side connection portion being connected to the inlet of the refrigerant in the evaporator, and the outlet-side connection portion being connected to the outlet of the refrigerant in the evaporator; a condenser, which is arranged on the downstream side of the outlet-side connection portion and is used to cool the refrigerant; and a bypass flow path, which branches off on the downstream side of the pump and the upstream side of the inlet-side connection portion and is used to allow the refrigerant to flow into the condenser without passing through the inlet-side connection portion and the outlet-side connection portion, wherein, at least when the evaporator is not connected to the inlet-side connection portion and the outlet-side connection portion, the refrigerant is circulated through the bypass flow path without passing through the inlet-side connection portion and the outlet-side connection portion.

[0012] The refrigerant circulation method in a circulation device for a two-phase cooling system according to the second aspect of the present invention is a refrigerant circulation method in a circulation device for a two-phase cooling system constituting a two-phase cooling system, wherein the two-phase cooling system circulates the refrigerant by connecting a detachable evaporator, and the refrigerant circulation method includes the following steps: causing the refrigerant to circulate through a bypass flow path for circulating the refrigerant instead of through the inlet side connection part and the outlet side connection part, at least when the evaporator is not connected to the inlet side connection part connected to the inlet of the refrigerant in the evaporator and the outlet side connection part connected to the outlet of the refrigerant in the evaporator; and cooling the refrigerant that circulates in the bypass flow path and flows into the condenser.

[0013] Effects of the Invention

[0014] As described above, the circulation device for a two-phase cooling system according to the first aspect of the present invention includes a bypass flow path branched off on the downstream side of the pump and the upstream side of the inlet-side connection portion, for allowing the refrigerant to flow into the condenser without passing through the inlet-side connection portion and the outlet-side connection portion, and at least when the evaporator is not connected to the inlet-side connection portion and the outlet-side connection portion, the refrigerant is circulated through the bypass flow path without passing through the inlet-side connection portion and the outlet-side connection portion. Thus, even when the detachable evaporator is not connected to the inlet-side connection portion and the outlet-side connection portion, the refrigerant can be circulated through the bypass flow path, so that the refrigerant can be continuously cooled by the condenser. Therefore, even soon after the detachable evaporator is reconnected after being removed from the inlet-side connection portion and the outlet-side connection portion, the cooled low-temperature refrigerant can flow into the evaporator, and the cooling object can be immediately cooled by the evaporator.

[0015] As described above, the refrigerant circulation method in the circulation device for a two-phase cooling system of the second aspect of the present invention includes the following steps: at least in a state where the evaporator is not connected to the inlet side connection part connected to the inlet of the refrigerant in the evaporator and the outlet side connection part connected to the outlet of the refrigerant in the evaporator, the refrigerant is caused to flow through the bypass flow path for circulating the refrigerant without passing through the inlet side connection part and the outlet side connection part; and the refrigerant that flows through the bypass flow path and flows into the condenser is cooled. Thus, as in the first aspect, even in a state where the detachable evaporator is not connected to the inlet side connection part and the outlet side connection part, the refrigerant can be circulated through the bypass flow path, so that the refrigerant can be continuously cooled by the condenser. Therefore, even soon after the detachable evaporator is reconnected after being removed from the inlet side connection part and the outlet side connection part, the cooled refrigerant with a low temperature can flow into the evaporator, and the cooling object can be immediately cooled by the evaporator. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram showing the structure of the two-phase cooling system circulation device in a state where the evaporator is connected according to the first embodiment.

[0017] Figure 2 This is a schematic diagram showing the structure of the two-phase cooling system circulation device according to the first embodiment in a state where the evaporator is not connected.

[0018] Figure 3 1 is a schematic diagram showing the structure of a two-phase cooling system circulation device according to a first modified example of the first embodiment.

[0019] Figure 4 1 is a schematic diagram showing the structure of a two-phase cooling system circulation device according to a second modified example of the first embodiment.

[0020] Figure 5 It is a schematic diagram showing the structure of the two-phase cooling system circulation device in the refrigerant recovery state according to the second embodiment.

[0021] Figure 6 This is a block diagram showing a control structure of a circulation device for a two-phase cooling system according to the second embodiment.

[0022] Figure 7 This is a graph for explaining the set liquid level according to the second embodiment.

[0023] Figure 8 This is a flowchart for explaining the refrigerant recovery process performed by the control unit according to the second embodiment.

[0024] Fig. 9 This is a graph for explaining the setting change amount based on the third modification example.

[0025] Fig.10 This is a block diagram showing a controllable structure of a circulation device for a two-phase cooling system according to a fourth modified example.

[0026] Fig.11 1 is a schematic diagram showing an example of notification by the display unit according to the fourth modification example.

[0027] Fig.12 1 is a schematic diagram showing the structure of a circulation device for a two-phase cooling system according to a fifth modification. DETAILED DESCRIPTION

[0028] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0029] [First embodiment]

[0030] (Overall structure of a circulation device for a two-phase cooling system)

[0031] Reference Figure 1 Next, the overall structure of the two-phase cooling system circulation device 100 according to the first embodiment will be described. Figure 1 The two-phase cooling system circulation device 100 is in a state where a detachable evaporator 80 is connected. The two-phase cooling system circulation device 100 constitutes a two-phase cooling system 200 that circulates a refrigerant by connecting a detachable evaporator 80. The state where the detachable evaporator 80 is connected refers to, for example, a normal operating state in which the evaporator 80 is installed in the two-phase cooling system circulation device 100 to cool a heat source 81 (a cooling object). In addition, the two-phase cooling system circulation device 100 of the first embodiment is a portable circulation device. Here, detachable means that the evaporator 80 directly installed in the two-phase cooling system circulation device 100 can be removed from the two-phase cooling system circulation device 100, or that the evaporator 80 or other evaporator that is the same as the removed evaporator 80 can be directly installed. In addition, two-phase cooling refers to cooling based on a gas-liquid mixed fluid that utilizes the heat of vaporization when a liquid changes into a gas.

[0032] In the figure, liquid refrigerant 1 is indicated by oblique lines (hatching) from upper right to lower left, and gas-liquid mixed refrigerant 2 is indicated by oblique lines (hatching) from upper left to lower right. In addition, the refrigerant moves in the direction indicated by the arrow in the two-phase cooling system circulation device 100.

[0033] like Figure 1 As shown, the circulation device 100 for a two-phase cooling system includes a pump 10, a condenser 20, a storage unit 30, an inlet side connection unit 41 and an outlet side connection unit 42, an inlet side opening and closing valve 51 and an outlet side opening and closing valve 52, a flow rate adjustment unit 60, and a refrigerant flow path 70. The refrigerant flow path 70 includes a first refrigerant flow path 71, a second refrigerant flow path 72, a third refrigerant flow path 73, a fourth refrigerant flow path 74, and a bypass flow path 75. In addition, the circulation device 100 for a two-phase cooling system is connected to a detachable evaporator 80. In addition, the "inlet side" in the inlet side connection unit 41 refers to the inlet side of the evaporator 80, and the "outlet side" in the outlet side connection unit 42 refers to the outlet side of the evaporator 80. In addition, the "inlet side" in the inlet side opening and closing valve 51 refers to the inlet side of the evaporator 80, and the "outlet side" in the outlet side opening and closing valve 52 refers to the outlet side of the evaporator 80.

[0034] One end of the first refrigerant flow path 71 is connected to the outlet of the pump 10, and the other end is connected to the inlet-side connection portion 41. A branch portion 76 is formed between one end and the other end of the first refrigerant flow path 71. One end of the second refrigerant flow path 72 is connected to the outlet-side connection portion 42, and the other end is connected to the inlet of the condenser 20. A confluence portion 77 is formed between one end and the other end of the second refrigerant flow path 72. One end of the third refrigerant flow path 73 is connected to the outlet of the condenser 20, and the other end is connected to the inlet of the storage portion 30. One end of the fourth refrigerant flow path 74 is connected to the outlet of the storage portion 30, and the other end is connected to the inlet of the pump 10.

[0035] The bypass flow path 75 is configured to branch from the first refrigerant flow path 71 to the second refrigerant flow path at the downstream side of the pump 10 and the upstream side of the inlet side connection portion 41 in the first refrigerant flow path 71, so that the refrigerant flows into the condenser 20 without passing through the inlet side connection portion 41 and the outlet side connection portion 42. The bypass flow path 75 branched from the first refrigerant flow path 71 is connected to a portion of the second refrigerant flow path 72 at the downstream side of the outlet side connection portion 42 and the upstream side of the condenser 20. In the first embodiment, one end of the bypass flow path 75 is connected to the branch portion 76 formed in the first refrigerant flow path 71, and the other end is connected to the confluence portion 77 formed in the second refrigerant flow path 72.

[0036] The refrigerant flow path 70 is formed of a metal material. The refrigerant flow path 70 is formed of, for example, a stainless steel material, an aluminum material, or a copper material. The refrigerant flow path 70 is formed in a tubular shape.

[0037] The pump 10 is configured to transport the refrigerant 1 in the liquid phase. The pump 10 is operated according to the output within a predetermined range. The pump 10 is configured to transport the refrigerant to the evaporator 80 via the first refrigerant flow path 71. The pump 10 is configured to transport the refrigerant to the condenser 20 via the first refrigerant flow path 71, the bypass flow path 75, and the second refrigerant flow path 72. The refrigerant flows into the pump 10 from the storage portion 30 via the fourth refrigerant flow path 74. The pump 10 is provided on the downstream side of the storage portion 30 in the fourth refrigerant flow path 74 and on the upstream side of the evaporator 80 in the first refrigerant flow path 71. Here, "the upstream side of the pump 10" refers to the part on the upstream side of the pump 10, excluding the pump 10. In addition, "the downstream side of the pump 10" refers to the part on the downstream side of the pump 10, excluding the pump 10. In addition, the upstream and downstream sides of the condenser 20, the upstream and downstream sides of the storage portion 30, and the upstream and downstream sides of the evaporator 80 are also the same.

[0038] The pump 10 takes in the liquid refrigerant 1 from the inlet of the pump 10 and ejects the liquid refrigerant 1 from the outlet of the pump 10. The pump 10 is a centrifugal pump. However, the pump 10 is not limited to a centrifugal pump. The pump 10 may also be a mixed flow pump, an axial flow pump, or other known pumps. In addition, it may also be a positive displacement pump.

[0039] The condenser 20 is configured to condense the gas phase refrigerant in the gas-liquid mixed refrigerant 2 flowing out of the evaporator 80 to generate the liquid phase refrigerant 1 in a state where the evaporator 80 is connected. In the first embodiment, the condenser 20 is configured to cool and condense the refrigerant by exchanging heat with the coolant 23 flowing in from the outside. The condenser 20 condenses the refrigerant by, for example, allowing the coolant 23 flowing from an external chiller (not shown) to flow into the inside of the condenser 20 to absorb the heat of the refrigerant. The condenser 20 includes a flow path 21 for the refrigerant to flow and a coolant flow path 22 for the coolant 23 to flow. In the condenser 20, the gas-liquid mixed refrigerant 2 flows into the condenser 20 from the inlet, and the liquid phase refrigerant 1 flows out from the outlet of the condenser 20.

[0040] The condenser 20 is arranged on the downstream side of the outlet side connection part 42 in the second refrigerant flow path 72. The refrigerant flows into the condenser 20 via the second refrigerant flow path 72. The refrigerant condensed by the condenser 20 flows into the storage part 30 via the third refrigerant flow path 73. The coolant 23 uses a coolant with a lower temperature than the liquid phase refrigerant 1. In the first embodiment, carbon dioxide is used as the refrigerant, and a liquid with hydrofluoroether as the main component is used as the coolant 23. The type of the coolant 23 is selected according to the type of the refrigerant. The coolant 23 is not particularly limited as long as it is a known coolant.

[0041] The storage section 30 is configured to store the liquid-phase refrigerant 1. In addition, the storage section 30 is configured to separate and store bubbles (gas-phase refrigerant) contained in the gas-liquid mixed refrigerant 2 in the upper part when there is a gas-liquid mixed refrigerant 2 that is not completely condensed in the condenser 20. The storage section 30 is provided on the downstream side of the condenser 20 in the third refrigerant flow path 73. In the storage section 30, the liquid-phase refrigerant 1 is flowed in from the inlet of the storage section 30, and the liquid-phase refrigerant 1 is flowed out from the outlet of the storage section 30. In addition, the storage section 30 is configured to send the liquid-phase refrigerant 1 to the pump 10 via the fourth refrigerant flow path 74.

[0042] The inlet-side connection portion 41 is configured to connect the first refrigerant flow path 71 to the inlet of the refrigerant in the evaporator 80. The inlet-side connection portion 41 connects the other end of the first refrigerant flow path 71 to the inlet of the refrigerant provided in the evaporator 80. The inlet-side connection portion 41 is, for example, a joint member that can be attached and detached relative to the inlet-side joint member 84 formed at the inlet of the refrigerant of the evaporator 80. For example, the inlet-side connection portion 41 uses a well-known joint such as a threaded joint, a flange joint, a quick joint, a bite joint, etc. The inlet-side connection portion 41 is provided on the downstream side of the pump 10.

[0043] The outlet-side connection portion 42 is configured to connect the outlet of the refrigerant in the evaporator 80 to the second refrigerant flow path 72. The outlet-side connection portion 42 connects the outlet of the refrigerant provided in the evaporator 80 to one end of the second refrigerant flow path 72. The outlet-side connection portion 42 is, for example, a joint member that can be attached and detached relative to the outlet-side joint member 85 formed at the outlet of the refrigerant of the evaporator 80. For example, the outlet-side connection portion 42 uses a well-known joint such as a threaded joint, a flange joint, a quick joint, and a bite joint. The outlet-side connection portion 42 is provided on the downstream side of the pump 10 and the evaporator 80 and on the upstream side of the condenser 20.

[0044] The inlet-side opening and closing valve 51 is arranged between the branch portion 76 provided in the first refrigerant flow path 71 and the inlet-side connection portion 41. That is, the inlet-side opening and closing valve 51 is arranged between the branch portion of the bypass flow path 75 branched from the first refrigerant flow path 71 on the downstream side of the pump 10 in the first refrigerant flow path and the inlet-side connection portion 41. The inlet-side opening and closing valve 51 is configured to be able to open and close the flow path. The inlet-side opening and closing valve 51 is, for example, an on-off valve that can switch the flow path between a fully open state and a fully closed state. In addition, the inlet-side opening and closing valve 51 can also be provided integrally with the inlet-side connection portion 41. In addition, the inlet-side opening and closing valve 51 can also be provided at the branch portion 76.

[0045] The outlet side opening and closing valve 52 is arranged between the outlet side connection part 42 and the confluence part 77 arranged in the second refrigerant flow path 72. That is, the outlet side opening and closing valve 52 is arranged between the outlet side connection part 42 in the second refrigerant flow path and the connection part connected to the bypass flow path 75 on the downstream side of the outlet side connection part 42. The outlet side opening and closing valve 52 is configured to open and close the flow path. The outlet side opening and closing valve 52 is, for example, a switch valve that can switch the flow path between a fully open state and a fully closed state. In addition, the outlet side opening and closing valve 52 can also be arranged integrally with the outlet side connection part 42. In addition, the outlet side opening and closing valve 52 can also be arranged at the confluence part 77.

[0046] The flow rate adjustment unit 60 is provided in the bypass flow path 75. The flow rate adjustment unit 60 is configured to increase the pressure loss of the bypass flow path 75 by reducing the flow path cross-sectional area of ​​a part of the bypass flow path 75. In the first embodiment, the flow rate adjustment unit 60 is an orifice 61. In order to adjust the distribution of the flow rate of the refrigerant flowing into the evaporator 80 and the flow rate of the refrigerant flowing into the bypass flow path 75 in a state where the evaporator 80 is connected, the aperture of the orifice 61 is preset. In the first embodiment, the aperture of the orifice 61 is set in such a way that the flow rate of the refrigerant flowing into the evaporator 80 is greater than the flow rate of the refrigerant flowing into the bypass flow path 75.

[0047] like Figure 1 As shown, in the circulation device 100 for a two-phase cooling system, the evaporator 80 is connected to the inlet-side connection portion 41 and the outlet-side connection portion 42. The evaporator 80 cools the heat source 81 by utilizing the heat of vaporization when a part of the liquid-phase refrigerant 1 transported through the inlet-side connection portion 41 evaporates and changes into the gas-liquid mixed refrigerant 2. The evaporator 80 includes a cold plate 82 and a refrigerant flow path 83 disposed inside the cold plate 82. The inlet of the refrigerant in the refrigerant flow path 83 is connected to the inlet-side connection portion 41, and the outlet of the refrigerant is connected to the outlet-side connection portion 42. The heat source 81 is disposed on one surface of the cold plate 82. The evaporator 80 is formed integrally with the heat source 81. In addition, Figure 1 The refrigerant flow path 83 shown is schematic. The refrigerant flow path 83 may also have a structure with multiple bends inside the evaporator 80 to efficiently perform heat exchange. In addition, the refrigerant flow path 83 may also be formed to be divided into multiple parts at the inlet and pass through the inside of the evaporator 80, and merge into one at the outlet. In addition, the structure of the evaporator 80 is not particularly limited.

[0048] In the first embodiment, the refrigerant is carbon dioxide. However, the type of the refrigerant is not limited thereto. The refrigerant may be, for example, freon or ammonia.

[0049] Figure 2 The two-phase cooling system circulation device 100 is in a state where the detachable evaporator 80 is not connected. The state where the detachable evaporator 80 is not connected refers to, for example, a state where the evaporator 80 is removed from the two-phase cooling system circulation device 100 due to maintenance of the heat source 81 or the evaporator 80. In the two-phase cooling system circulation device 100 in a state where the evaporator 80 is not connected, the inlet-side on-off valve 51 and the outlet-side on-off valve 52 are in a closed state.

[0050] The condenser 20 is configured to cool the liquid phase refrigerant 1 sent from the pump 10 via the bypass flow path 75 when the evaporator 80 is not connected. In the condenser 20, the liquid phase refrigerant 1 flows into the condenser 20 from the inlet, and the cooled liquid phase refrigerant 1 flows out from the outlet of the condenser 20 when the evaporator 80 is not connected. In addition, the other structures of the two-phase cooling system circulation device 100 when the evaporator 80 is not connected are the same as those of the reference numerals. Figure 1 The configuration of the two-phase cooling system circulation device 100 in the state in which the evaporator 80 is connected is the same as that described above, and thus the description thereof will be omitted.

[0051] (Circulation of refrigerant)

[0052] Reference Figure 1 The circulation of the refrigerant in the two-phase cooling system circulation device 100 in a state where the evaporator 80 is connected to the inlet-side connection portion 41 and the outlet-side connection portion 42 will be described.

[0053] The liquid-phase refrigerant 1 is delivered from the pump 10. The refrigerant flows through the first refrigerant flow path 71. At the branch portion 76 of the first refrigerant flow path 71, a portion of the refrigerant flows through the inlet-side on-off valve 51 and the inlet-side connection portion 41 in a fully opened state and flows into the evaporator 80. The remaining portion of the refrigerant flows into the bypass flow path 75 as described later. A portion of the liquid-phase refrigerant 1 flowing into the evaporator 80 evaporates and changes into a gas-liquid mixed refrigerant 2. The gas-liquid mixed refrigerant 2 flows from the evaporator 80 through the outlet-side connection portion 42 into the second refrigerant flow path 72. The gas-liquid mixed refrigerant 2 flowing into the second refrigerant flow path 72 flows through the outlet-side on-off valve 52 and the confluence portion 77 in a fully opened state. In the confluence portion 77, the gas-liquid mixed refrigerant 2 merges with the liquid-phase refrigerant 1 flowing from the bypass flow path 75. The gas-liquid mixed refrigerant 2 after the confluence and the liquid-phase refrigerant 1 flowing in from the bypass flow path 75 flow into the condenser 20 in a gas-liquid mixed state. The gas-phase refrigerant in the gas-liquid mixed refrigerant 2 flowing into the condenser 20 is condensed and changed into the liquid-phase refrigerant 1. The condensed liquid-phase refrigerant 1 flows from the condenser 20 through the third refrigerant flow path 73 and flows into the storage section 30. The refrigerant flowing into the storage section 30 flows through the fourth refrigerant flow path 74 and flows into the pump 10.

[0054] In addition, at the branching portion 76 of the first refrigerant flow path 71, the remaining portion of the liquid-phase refrigerant 1 flows into the bypass flow path 75. The refrigerant flowing into the bypass flow path 75 flows through the throttle hole 61 provided in the bypass flow path 75 and flows into the confluence portion 77 of the second refrigerant flow path 72. In the confluence portion 77, the liquid-phase refrigerant 1 flowing in from the bypass flow path 75 merges with the gas-liquid mixed refrigerant 2.

[0055] Next, refer to Figure 2 The circulation of the refrigerant in the two-phase cooling system circulation device 100 in a state where the evaporator 80 is not connected to the inlet-side connection portion 41 and the outlet-side connection portion 42 will be described.

[0056] In the state where the evaporator 80 is not connected, the inlet-side opening and closing valve 51 and the outlet-side opening and closing valve 52 are completely closed to prevent the liquid-phase refrigerant 1 from flowing out from the inlet-side connection portion 41 and the gas-liquid mixed refrigerant 2 from flowing out from the outlet-side connection portion 42. Thus, unlike the state where the evaporator 80 is connected to the inlet-side connection portion 41 and the outlet-side connection portion 42, at the branch portion 76 of the first refrigerant flow path 71, the liquid-phase refrigerant 1 other than the refrigerant 1 flowing from the branch portion 76 to the inlet-side opening and closing valve 51 flows into the bypass flow path 75. In addition, at the confluence portion 77 of the second refrigerant flow path 72, the liquid-phase refrigerant 1 flowing in from the bypass flow path 75 flows through the second refrigerant flow path 72 and flows into the condenser 20.

[0057] The liquid-phase refrigerant 1 is delivered from the pump 10. The liquid-phase refrigerant 1 flows through the first refrigerant flow path 71. At the branch portion 76 of the first refrigerant flow path 71, the liquid-phase refrigerant 1 flows into the bypass flow path 75. The liquid-phase refrigerant 1 flowing into the bypass flow path 75 flows through the throttle hole 61 provided in the bypass flow path 75 and flows into the confluence portion 77 of the second refrigerant flow path 72. The liquid-phase refrigerant 1 flowing into the confluence portion 77, except for the refrigerant 1 flowing between the confluence portion 77 and the outlet-side on-off valve 52, flows through the second refrigerant flow path 72 and flows into the condenser 20. The liquid-phase refrigerant 1 flowing into the condenser 20 is cooled or maintained in a cooled state. The liquid-phase refrigerant 1 flows from the condenser 20 through the third refrigerant flow path 73 and flows into the storage portion 30. The refrigerant that has flowed into the storage portion 30 flows through the fourth refrigerant flow path 74 and flows into the pump 10 .

[0058] (Effects of the First Embodiment)

[0059] In the first embodiment, the following effects can be obtained.

[0060] In the first embodiment, as described above, the bypass flow path 75 is provided, which is branched at the downstream side of the pump 10 and the upstream side of the inlet-side connection portion 41, and is used to allow the refrigerant to flow into the condenser 20 without passing through the inlet-side connection portion 41 and the outlet-side connection portion 42. At least when the evaporator 80 is not connected to the inlet-side connection portion 41 and the outlet-side connection portion 42, the refrigerant circulates through the bypass flow path 75 without passing through the inlet-side connection portion 41 and the outlet-side connection portion 42. Thus, even when the detachable evaporator 80 is not connected to the inlet-side connection portion 41 and the outlet-side connection portion 42, the liquid-phase refrigerant 1 can be circulated through the bypass flow path 75, and thus the liquid-phase refrigerant 1 can be continuously cooled by the condenser 20. Therefore, even soon after the detachable evaporator 80 is removed from the inlet side connection part 41 and the outlet side connection part 42 and then reconnected, the cooled low-temperature liquid phase refrigerant 1 can flow into the evaporator 80, and the heat source 81 can be immediately cooled by the evaporator 80.

[0061] In the first embodiment, as described above, the refrigerant circulation method includes the steps of: causing the refrigerant to flow through the bypass flow path 75 for causing the refrigerant to flow, not through the inlet-side connection portion 41 and the outlet-side connection portion 42, at least in a state where the evaporator 80 is not connected to the inlet-side connection portion 41 and the outlet-side connection portion 42; and cooling the refrigerant that flows through the bypass flow path 75 and flows into the condenser 20. Thus, even in a state where the detachable evaporator 80 is not connected to the inlet-side connection portion 41 and the outlet-side connection portion 42, the liquid-phase refrigerant 1 can be circulated through the bypass flow path 75, and thus the liquid-phase refrigerant 1 can be continuously cooled by the condenser 20. Therefore, even soon after the detachable evaporator 80 is detached from the inlet-side connection portion 41 and the outlet-side connection portion 42 and then connected again, the cooled liquid-phase refrigerant 1 with a low temperature can flow into the evaporator 80, and the heat source 81 can be immediately cooled by the evaporator 80.

[0062] In addition, in the first embodiment, by configuring as follows, further effects as described below are obtained.

[0063] That is, in the first embodiment, as described above, in the normal operation state in which the evaporator 80 is connected to the inlet-side connection portion 41 and the outlet-side connection portion 42, a part of the refrigerant is circulated through the evaporator 80, and the remaining part of the refrigerant is circulated through the bypass flow path 75. Thus, in the normal operation state in which the evaporator 80 is connected to the inlet-side connection portion 41 and the outlet-side connection portion 42, even if the refrigerant cannot circulate through the evaporator 80 due to clogging of the evaporator 80, the liquid-phase refrigerant 1 can be circulated through the bypass flow path 75. Therefore, it is possible to suppress the occurrence of a malfunction of the two-phase cooling system circulation device 100 caused by a pressure increase at the outlet of the pump 10 due to the inability to circulate the refrigerant.

[0064] In addition, in the first embodiment, as described above, the flow rate adjustment unit 60 provided in the bypass flow path 75 is further provided. The flow rate adjustment unit 60 can reduce the flow path cross-sectional area of ​​a part of the bypass flow path 75, so that the pressure loss of the bypass flow path 75 can be increased. Thus, in a state where the evaporator 80 is connected, the flow rate of the refrigerant flowing into the bypass flow path 75 can be reduced. Therefore, in a state where the evaporator 80 is connected, the flow rate of the refrigerant flowing into the evaporator 80 and the flow rate of the refrigerant flowing into the bypass flow path 75 can be adjusted in such a manner that the flow rate of the refrigerant flowing into the evaporator 80 is greater than the flow rate of the refrigerant flowing into the bypass flow path 75.

[0065] In the first embodiment, as described above, the flow rate adjustment unit 60 is the orifice 61 that adjusts the flow rate of the refrigerant flowing in the bypass flow path 75. The orifice 61 can increase the pressure loss of the bypass flow path 75, so the flow rate of the refrigerant flowing into the bypass flow path 75 can be reduced. Therefore, the refrigerant flow rate of the liquid phase refrigerant 1 flowing into the evaporator 80 at the branch portion 76 and the refrigerant flow rate of the liquid phase refrigerant 1 flowing into the bypass flow path 75 can be adjusted by a simple structure so that the flow rate of the refrigerant flowing into the evaporator 80 is greater than the flow rate of the refrigerant flowing into the bypass flow path 75.

[0066] In the first embodiment, as described above, the condenser 20 is configured to condense and cool the gas phase refrigerant contained in the gas-liquid mixed refrigerant 2 in the refrigerant, or to cool the liquid phase refrigerant 1 in the refrigerant, by the cooling liquid 23 flowing in from the outside. The gas phase refrigerant and the liquid phase refrigerant 1 contained in the gas-liquid mixed refrigerant 2 are cooled by the cooling liquid 23 flowing in from the outside, so that the structure of the condenser 20 can be simplified and the refrigerant can be reliably cooled.

[0067] In addition, in the first embodiment, as described above, the bypass flow path 75 is branched at the downstream side of the pump 10 and the upstream side of the inlet side connection portion 41, and is connected to the downstream side of the outlet side connection portion 42 and the upstream side of the condenser 20. Thus, the bypass flow path 75 is not directly connected to the condenser 20, but is connected to the flow path between the outlet side connection portion 42 and the condenser 20. Therefore, a plurality of refrigerant flow paths are not connected to the condenser 20, so that the structure of the condenser 20 can be further simplified. Therefore, the enlargement of the circulation device 100 for the two-phase cooling system can be further suppressed.

[0068] In addition, in the first embodiment, as described above, there are also provided: an inlet-side opening and closing valve 51, which is provided between the branch portion from which the bypass flow path 75 is branched on the downstream side of the pump 10 and the inlet-side connection portion 41, for opening and closing the flow path of the refrigerant; and an outlet-side opening and closing valve 52, which is provided between the outlet-side connection portion 42 and the connection portion to which the bypass flow path 75 is connected on the downstream side of the outlet-side connection portion 42, for opening and closing the flow path of the refrigerant. Thus, in a state where the evaporator 80 is not connected, by completely closing the inlet-side opening and closing valve 51 and the outlet-side opening and closing valve 52, it is possible to prevent the liquid-phase refrigerant 1 from flowing out of the inlet-side connection portion 41 and the gas-liquid mixed refrigerant 2 from flowing out of the outlet-side connection portion 42. Furthermore, when the evaporator 80 is removed from the inlet-side connection portion 41 and the outlet-side connection portion 42, the inlet-side on-off valve 51 and the outlet-side on-off valve 52 are completely closed before the evaporator 80 is removed, thereby allowing the liquid-phase refrigerant 1 circulating through the bypass flow path 75 to be cooled by the condenser 20 without stopping the condenser 20. Therefore, even soon after the detachable evaporator 80 is connected to the inlet-side connection portion 41 and the outlet-side connection portion 42, the appropriately cooled refrigerant can flow into the evaporator 80, and the heat source 81 can be further immediately cooled by the evaporator 80.

[0069] In the first embodiment, as described above, the storage unit 30 is further provided on the downstream side of the condenser 20 and the upstream side of the pump 10. Thus, when there is a gas-liquid mixed refrigerant 2 that is not completely condensed in the condenser 20, the storage unit 30 separates the bubbles (gas-phase refrigerant) contained in the gas-liquid mixed refrigerant 2, thereby enabling only the liquid-phase refrigerant 1 to be sent to the pump 10. Therefore, it is possible to suppress the occurrence of a malfunction of the pump 10 caused by the bubbles (gas-phase refrigerant) contained in the refrigerant.

[0070] In the first embodiment, as described above, in a state where the evaporator 80 is connected to the inlet-side connection portion 41 and the outlet-side connection portion 42, the gas-liquid mixed refrigerant 2 flowing out of the evaporator 80 flows into the condenser 20. Thus, the gas-liquid mixed refrigerant 2 flows out of the evaporator 80 without completely evaporating the liquid-phase refrigerant 1 in the evaporator 80, and thus, insufficient cooling of the heat source using the latent heat of evaporation in the evaporator 80 can be suppressed.

[0071] [Second embodiment]

[0072] Reference Figures 5 to 8 The overall structure of the two-phase cooling system circulation device 300 according to the second embodiment and the refrigerant recovery method for recovering the refrigerant from the evaporator 80 will be described.

[0073] For example, when maintaining an evaporator installed in a circulation device for a two-phase cooling system, the evaporator installed in the circulation device for a two-phase cooling system is removed from the circulation device for a two-phase cooling system. When the liquid-phase refrigerant is retained in the refrigerant flow path inside the evaporator when the evaporator is removed from the circulation device for a two-phase cooling system, sometimes the retained liquid-phase refrigerant vaporizes and flows out, causing loss of the refrigerant and freezing due to the heat of vaporization. Therefore, in order to reduce the amount of refrigerant retained inside the evaporator when the evaporator is removed from the circulation device for a two-phase cooling system, it is necessary to recover the refrigerant retained in the refrigerant flow path inside the evaporator to the storage unit before removing the evaporator from the circulation device for a two-phase cooling system.

[0074] (Overall structure of a circulation device for a two-phase cooling system)

[0075] Reference Figure 5 and Figure 6 Next, the overall structure of a two-phase cooling system circulation device 300 according to the second embodiment will be described. Figure 5 The two-phase cooling system circulation device 300 is in a refrigerant recovery state when the refrigerant is recovered from the evaporator 80. In the two-phase cooling system circulation device 300, in the refrigerant recovery state, the evaporator 80 is connected to the inlet side connection part 41 and the outlet side connection part 42, the inlet side opening and closing valve 51 is in a closed state, and the outlet side opening and closing valve 52 is in an open state. In addition, the same reference numerals are attached to the same structures as those in the first embodiment, and the description thereof is omitted.

[0076] The two-phase cooling system circulation device 300 according to the second embodiment is further provided with an inlet-side on-off valve opening and closing mechanism 53, an outlet-side on-off valve opening and closing mechanism 54, a detection unit 31, and a control device 90 (see Figure 6 ).

[0077] The inlet-side on-off valve opening and closing mechanism 53 is configured to be able to switch the inlet-side on-off valve 51 between an open state and a closed state. The inlet-side on-off valve opening and closing mechanism 53 includes, for example, a motor. The inlet-side on-off valve opening and closing mechanism 53 and the control unit 91 (see Figure 6 The inlet-side on-off valve 51 is opened and closed by the inlet-side on-off valve opening and closing mechanism 53 under the control of the control unit 91.

[0078] The outlet side on-off valve opening and closing mechanism 54 is configured to be able to switch the outlet side on-off valve 52 between an open state and a closed state. The outlet side on-off valve opening and closing mechanism 54 includes, for example, a motor. The outlet side on-off valve opening and closing mechanism 54 and the control unit 91 (see Figure 6 ) is connected. The outlet side opening and closing valve 52 is opened and closed by the outlet side opening and closing valve opening and closing mechanism 54 according to the control of the control unit 91. In addition, the structures of the inlet side opening and closing valve opening and closing mechanism 53 and the outlet side opening and closing valve opening and closing mechanism 54 are not particularly limited as long as they are well-known valve opening and closing mechanisms.

[0079] The detection unit 31 is configured to detect the amount of refrigerant recovered. Specifically, the detection unit 31 is configured to detect the amount of refrigerant stored in the storage unit 30 as the amount of refrigerant recovered. The detection unit 31 is, for example, a liquid level sensor that detects the liquid level 3 (see FIG. 1 ) of the liquid phase refrigerant stored in the storage unit 30. Figure 7 ) for determination.

[0080] like Figure 6 As shown, the control device 90 includes a control unit 91 and a storage unit 92. The control unit 91 is configured to perform control to stop the operation of the pump 10 and end the recovery process of the refrigerant based on the detection result of the detection unit 31. In addition, the control unit 91 is configured to perform control to close the outlet side opening and closing valve 52 through the outlet side opening and closing valve opening and closing mechanism 54 based on the detection result of the detection unit 31 to prevent the refrigerant from flowing out of the outlet side opening and closing valve 52 to the outlet side connection part 42 side. The control unit 91 is composed of a processor such as a CPU (Central Processing Unit). The storage unit 92 is configured to include a volatile storage device and a non-volatile storage device. The storage unit 92 stores the set storage amount of the refrigerant in the storage unit 30 described later, a program for setting the storage amount, and the like. In addition, the set storage amount includes the set liquid level 5 described later (see Figure 7 ). In addition, the program for setting the storage amount includes a program for setting the liquid level 5. In addition, the volatile storage device is used for temporary storage when the control unit 91 performs calculations.

[0081] (Circulation of refrigerant when recovering refrigerant from evaporator)

[0082] Reference Figure 5 The circulation of the refrigerant when the refrigerant is recovered from the evaporator 80 connected to the two-phase cooling system circulation device 300 will be described.

[0083] In the two-phase cooling system circulation device 300 in the refrigerant recovery state, the evaporator 80 is connected to the inlet side connection part 41 and the outlet side connection part 42. In addition, the inlet side opening and closing valve 51 is closed, and the outlet side opening and closing valve 52 is open. The heat source 81 does not generate heat.

[0084] The liquid-phase refrigerant 1 is delivered from the pump 10. The liquid-phase refrigerant 1 flows through the first refrigerant flow path 71. Since the inlet-side on-off valve 51 is in a fully closed state, at the branch portion 76 of the first refrigerant flow path 71, the refrigerant 1 in the liquid phase other than the refrigerant 1 flowing between the branch portion 76 and the inlet-side on-off valve 51 flows into the bypass flow path 75. The liquid-phase refrigerant 1 flowing into the bypass flow path 75 flows into the confluence portion 77 of the second refrigerant flow path 72. The liquid-phase refrigerant 1 flowing into the confluence portion 77 flows through the second refrigerant flow path 72 and flows into the condenser 20. The refrigerant flowing into the condenser 20 flows through the third refrigerant flow path 73 and flows into the storage portion 30. The refrigerant flowing into the storage portion 30 flows through the fourth refrigerant flow path 74 and flows into the pump 10.

[0085] The liquid-phase refrigerant 1 is not delivered from the pump 10 to the evaporator 80. Therefore, the liquid-phase refrigerant 1 circulating in the two-phase cooling system circulation device 300 does not flow into the evaporator 80 in the refrigerant recovery state. Then, shortly after the inlet-side on-off valve 51 is completely closed, the liquid-phase refrigerant 1 is retained in the refrigerant flow path 83 inside the evaporator 80. Although the heat generation of the heat source 81 stops, the temperature inside the evaporator 80 rises due to the heat from the outside air. Due to the increase in the temperature inside the evaporator 80, the temperature and pressure of the liquid-phase refrigerant 1 retained in the evaporator 80 rise, and a part of the liquid-phase refrigerant 1 evaporates and changes into the gas-liquid mixed refrigerant 2.

[0086] Here, the liquid phase refrigerant 1 delivered from the pump 10 flows into the confluence portion 77 of the second refrigerant flow path 72 from the bypass flow path 75, and circulates through the second refrigerant flow path 72, the condenser 20, the third refrigerant flow path 73, the storage portion 30, and the fourth refrigerant flow path 74. The circulating liquid phase refrigerant 1 is cooled or maintained in a cooled state by the condenser 20. Therefore, the pressure of the gas phase refrigerant in the gas-liquid mixed refrigerant 2 retained in the evaporator 80 is greater than the pressure of the liquid phase refrigerant 1 circulating in the two-phase cooling system circulation device 300. That is, the pressure difference between the pressure of the gas phase refrigerant contained in the gas-liquid mixed refrigerant 2 in the evaporator 80 and the pressure of the liquid phase refrigerant 1 circulating in the path from the confluence portion 77 of the second refrigerant flow path 72 through the condenser 20, the storage portion 30, the pump 10, and the bypass flow path 75 becomes larger. Due to the pressure difference, the gas-liquid mixed refrigerant 2 in the evaporator 80 flows out from the evaporator 80 toward the confluence portion 77 of the second refrigerant flow path 72. Specifically, the gas-phase refrigerant in the gas-liquid mixed refrigerant 2 in the evaporator 80 flows out from the evaporator 80 toward the confluence portion 77 of the second refrigerant flow path 72, and the liquid-phase refrigerant in the gas-liquid mixed refrigerant 2 in the evaporator 80 flows out in a manner of being squeezed out from the evaporator 80. Then, in the confluence portion 77, the gas-liquid mixed refrigerant 2 flowing out from the evaporator 80 merges with the liquid-phase refrigerant 1 flowing in from the bypass flow path 75, and the gas-phase refrigerant contained in the merged gas-liquid mixed refrigerant 2 is condensed. The merged liquid-phase refrigerant 1 flows through the second refrigerant flow path 72 and flows into the condenser 20. That is, the gas-liquid mixed refrigerant 2 in the evaporator 80 flows through the second refrigerant flow path 72 and is guided to the condenser 20.

[0087] Thus, the refrigerant retained in the refrigerant flow path inside the evaporator 80 is recovered in the storage portion 30. In addition, since the flow path 83 inside the evaporator 80 cannot be evacuated, it is not possible to recover all the refrigerant in the evaporator 80. However, the amount of refrigerant retained inside the evaporator 80 when the evaporator 80 is removed from the two-phase cooling system circulation device 300 can be reduced.

[0088] (Control unit terminates refrigerant recovery process based on detection result of detection unit)

[0089] Reference Figure 7 The control by the control unit 91 to terminate the refrigerant recovery process based on the detection result of the detection unit 31 will be described.

[0090] The control unit 91 is configured to control the outlet-side on-off valve 52 to be closed to prevent the refrigerant from flowing out of the outlet-side on-off valve 52 to the outlet-side connecting portion 42 side, and to control the pump 10 to stop the operation and end the refrigerant recovery process when the storage amount of the refrigerant detected by the detection unit 31 when the refrigerant is circulated through the bypass flow path 75 without passing through the evaporator 80 becomes a preset storage amount or more in the refrigerant recovery state. In addition, the set storage amount includes the set liquid level 5. In addition, the storage amount of the refrigerant includes the liquid level 3 of the refrigerant.

[0091] First, if Figure 2 As shown in FIG. 1 , before the two-phase cooling system circulation device 300 is connected to the evaporator 80, the refrigerant is circulated through the bypass flow path 75 instead of the inlet side connection portion 41 and the outlet side connection portion 42. That is, the refrigerant circulates in the two-phase cooling system circulation device 300 when the evaporator 80 is not connected to the inlet side connection portion 41 and the outlet side connection portion 42. At this time, the detection unit 31 (refer to FIG. 1 ) Figure 5 ) The liquid level of the liquid phase refrigerant 1 stored in the storage section 30 is measured.

[0092] Here, if the liquid level 3 (refer to Figure 7 ) is equal to the liquid level of the liquid phase refrigerant 1 stored in the storage unit 30 when the evaporator 80 is not connected, it can be said that the refrigerant retained in the evaporator 80 is recovered to the storage unit 30. However, as described above, it is impossible to recover all the refrigerant in the evaporator 80. Therefore, if Figure 7 As shown, the set liquid level 5 is set based on the liquid level 4 of the liquid phase refrigerant 1 stored in the storage section 30 when the evaporator 80 is not connected. The set liquid level 5 refers to the liquid level of the liquid phase refrigerant 1 stored in the storage section 30 in the refrigerant recovery state, which is set in a manner that subtracts a margin such as the amount of refrigerant that is not completely recovered in the evaporator 80 from the liquid level 4 of the liquid phase refrigerant 1 stored in the storage section 30 when the evaporator 80 is not connected. Therefore, when the liquid level of the liquid phase refrigerant stored in the storage section 30 in the refrigerant recovery state becomes above the set liquid level 5, it can be regarded that the refrigerant retained in the evaporator 80 is recovered in the storage section 30.

[0093] The set liquid level 5 is set by the control unit 91. That is, the control unit 91 acquires the liquid level 4 of the liquid phase refrigerant 1 stored in the storage unit 30 in a state where the evaporator 80 is not connected, which is detected by the detection unit 31, and executes the program for setting the set liquid level 5 stored in the storage unit 92, thereby setting the set liquid level 5. The set liquid level 5 is stored in the storage unit 92.

[0094] Then, for example, when the evaporator 80 is removed from the two-phase cooling system circulation device 300 for maintenance of the evaporator 80, the refrigerant is recovered from the evaporator 80 before the evaporator 80 is removed. Figure 1 The evaporator 80 shown is connected to the inlet side connection part 41 and the outlet side connection part 42, and the inlet side opening and closing valve 51 and the outlet side opening and closing valve 52 are in the open state, and the heat source 81 is cooled by the evaporator 80, as shown in FIG. Figure 5 As shown, in the refrigerant recovery state in which the evaporator 80 is connected to the inlet side connection part 41 and the outlet side connection part 42, and the inlet side opening and closing valve 51 is closed and the outlet side opening and closing valve 52 is opened, the refrigerant is circulated through the bypass flow path 75 instead of through the evaporator 80. In the refrigerant recovery state, the heat generation of the heat source 81 stops. At this time, the detection unit 31 detects the liquid level 3 (refer to the liquid level 3) of the liquid phase refrigerant 1 stored in the storage unit 30 in the refrigerant recovery state. Figure 7 ) for determination.

[0095] The control unit 91 obtains the liquid level 3 of the liquid-phase refrigerant 1 stored in the storage unit 30 detected by the detection unit 31. Figure 7 As shown, as time t passes, the liquid level h (liquid level 3) of the liquid phase refrigerant 1 stored in the storage unit 30 rises. When the liquid level 3 of the liquid phase refrigerant 1 detected by the detection unit 31 becomes higher than the preset set liquid level 5 (time t1), the control unit 91 controls the outlet side opening and closing valve 52 to close so as to prevent the refrigerant from flowing out of the outlet side opening and closing valve 52 to the outlet side connection unit 42 side, and controls the operation of the pump 10 to stop and end the refrigerant recovery process.

[0096] (Refrigerant recovery process performed by the control unit)

[0097] Reference Figure 8 Next, the refrigerant recovery process performed by the control unit 91 according to the second embodiment will be described. In addition, the order of the processing steps can be switched or executed simultaneously as long as there is no contradiction.

[0098] In step S1, in a state where the evaporator 80 is connected, the inlet-side on-off valve 51 and the outlet-side on-off valve 52 are in an open state, and the heat source 81 is cooled by the evaporator 80, after the heat generation of the heat source 81 stops, the control unit 91 closes the inlet-side on-off valve 51 through the inlet-side on-off valve opening and closing mechanism 53 to enter a refrigerant recovery state. In the refrigerant recovery state, the refrigerant circulates through the bypass flow path 75 instead of the evaporator 80. Thereafter, the process proceeds to step S2.

[0099] In step S2, the control unit 91 acquires the liquid level 3 of the liquid-phase refrigerant 1 stored in the storage unit 30 detected by the detection unit 31. Thereafter, the process proceeds to step S3.

[0100] In step S3, when the liquid level 3 of the acquired liquid phase refrigerant 1 is above the set liquid level 5 ("Yes" in step S3), the control unit 91 causes the processing to enter step S4; when it is less than the set liquid level 5 ("No" in step S3), the control unit 91 causes the processing to enter step S2.

[0101] In step S4, the control unit 91 closes the outlet-side on-off valve 52 via the outlet-side on-off valve opening and closing mechanism 54. Thereafter, the process proceeds to step S5.

[0102] In step S5, the control unit 91 stops the operation of the pump 10. Thereafter, the refrigerant recovery process ends.

[0103] (Effects of the Second Embodiment)

[0104] In the second embodiment, the following effects can be obtained.

[0105] In the second embodiment, as described above, the inlet-side opening and closing valve 51 for opening and closing the flow path of the refrigerant is further provided between the branching portion 76 from which the bypass flow path 75 is branched on the downstream side of the pump 10 and the inlet-side connection portion 41. When the refrigerant is recovered from the evaporator 80, in the refrigerant recovery state where the evaporator 80 is connected to the inlet-side connection portion 41 and the outlet-side connection portion 42 and the inlet-side opening and closing valve 51 is closed, the refrigerant is circulated through the bypass flow path 75 without passing through the evaporator 80, and the refrigerant in the evaporator 80 is guided to the condenser 20. Since the inlet-side opening and closing valve 51 is closed, the circulating liquid-phase refrigerant 1 does not flow into the evaporator 80, and the evaporator 80 receives heat from the outside air, so that the temperature inside the evaporator 80 rises. Therefore, the temperature and pressure of the liquid-phase refrigerant 1 retained in the evaporator 80 rise, and a part of the liquid-phase refrigerant 1 in the evaporator 80 evaporates and changes into the gas-liquid mixed refrigerant 2. Thus, a pressure difference is generated between the pressure of the gas phase refrigerant contained in the gas-liquid mixed refrigerant 2 in the evaporator 80 and the pressure of the liquid phase refrigerant 1 circulating in the path from the confluence portion 77 of the second refrigerant flow path 72 through the condenser 20, the storage portion 30, the pump 10, and the bypass flow path 75, so that the gas-liquid mixed refrigerant 2 in the evaporator 80 can flow out from the evaporator 80 toward the confluence portion 77 of the second refrigerant flow path 72. In addition, the liquid phase refrigerant 1 in the evaporator 80 can be changed into the gas-liquid mixed refrigerant 2 by the increase in the temperature inside the evaporator 80, so it is not necessary to provide additional equipment such as a heater for changing into the gas-liquid mixed refrigerant 2. For these reasons, the increase in the number of components and the complication of the structure can be suppressed, and the refrigerant retained in the refrigerant flow path 83 inside the evaporator 80 can be easily recovered.

[0106] In addition, in the second embodiment, as described above, there are further provided: a detection unit 31 that detects the amount of recovered refrigerant; and a control unit 91 that stops the operation of the pump 10 and ends the recovery process of the refrigerant based on the detection result of the detection unit 31. Thus, the recovery process of the refrigerant can be ended based on the detection result of the detection unit 31 that detects the amount of recovered refrigerant. Therefore, the recovery process of the refrigerant can be reliably performed based on the detection result of the detection unit 31 that detects the amount of recovered refrigerant.

[0107] In addition, in the second embodiment, as described above, the storage unit 30 is further provided on the downstream side of the condenser 20 and the upstream side of the pump 10, and the detection unit 31 detects the storage amount of the refrigerant stored in the storage unit 30 as the recovery amount of the refrigerant. Thus, based on the detection result of the storage amount of the refrigerant stored in the storage unit 30 as the recovery amount of the refrigerant, the operation of the pump 10 can be stopped and the recovery process of the refrigerant can be ended. Therefore, the detection result of the recovery amount of the refrigerant can be obtained by the simple structure of the detection unit 31, so that the complexity of the structure of the circulation device 300 for the two-phase cooling system can be suppressed.

[0108] In the second embodiment, as described above, in the refrigerant recovery state, when the storage amount of the refrigerant detected by the detection unit 31 when the refrigerant is circulated through the bypass flow path 75 without passing through the evaporator 80 becomes equal to or larger than the preset storage amount, the control unit 91 performs control to stop the operation of the pump 10 and terminate the refrigerant recovery process. Thus, it is possible to more easily detect that the refrigerant retained in the evaporator 80 has been recovered to the storage unit 30 based on the set storage amount. Therefore, it is possible to more easily and reliably perform the refrigerant recovery process based on the set storage amount.

[0109] In the second embodiment, as described above, an outlet-side on-off valve 52 for opening and closing the flow path of the refrigerant is provided between the outlet-side connection portion 42 and the connection portion connected to the bypass flow path 75 on the downstream side of the outlet-side connection portion 42, and the control unit 91 performs control to close the outlet-side on-off valve 52 to prevent the refrigerant from flowing out of the outlet-side on-off valve 52 to the outlet-side connection portion 42 side based on the detection result of the detection unit 31. Thus, when the evaporator 80 is removed from the two-phase cooling system circulation device 300, for example, the refrigerant can be prevented from flowing out of the outlet-side on-off valve 52 to the outside, and thus additional charging of the refrigerant can be suppressed.

[0110] In the second embodiment, as described above, the refrigerant circulation method further includes the following steps: when recovering the refrigerant from the evaporator 80, in a refrigerant recovery state in which the evaporator 80 is connected to the inlet-side connection portion 41 and the outlet-side connection portion 42 and the inlet-side opening and closing valve 51 provided between the branch portion 76 from which the bypass flow path 75 is branched and the inlet-side connection portion 41 is closed, the refrigerant is circulated through the bypass flow path 75 without passing through the evaporator 80, and the refrigerant of the evaporator 80 is guided to the condenser 20; and based on the detection result of the recovered amount of the refrigerant, the circulation of the refrigerant is stopped and the recovery process of the refrigerant is terminated. Since the inlet-side opening and closing valve 51 is closed, the circulating liquid-phase refrigerant 1 does not flow into the evaporator 80, and the evaporator 80 is input with heat from the outside air, so the temperature inside the evaporator 80 rises. Therefore, the temperature and pressure of the liquid-phase refrigerant 1 retained in the evaporator 80 rise, and a part of the liquid-phase refrigerant 1 evaporates and changes into the gas-liquid mixed refrigerant 2. Thus, a pressure difference is generated between the pressure of the gas phase refrigerant contained in the gas-liquid mixed refrigerant 2 in the evaporator 80 and the pressure of the liquid phase refrigerant 1 circulating in the path from the confluence portion 77 of the second refrigerant flow path 72 through the condenser 20, the storage portion 30, the pump 10, and the bypass flow path 75, so that the gas-liquid mixed refrigerant 2 in the evaporator 80 can flow out from the evaporator 80 toward the confluence portion 77 of the second refrigerant flow path 72. In addition, the liquid phase refrigerant 1 in the evaporator 80 can be changed into the gas-liquid mixed refrigerant 2 by the increase in the temperature inside the evaporator 80, so it is not necessary to provide additional equipment such as a heater for changing into the gas-liquid mixed refrigerant 2. For these reasons, the increase in the number of components and the complication of the structure can be suppressed, and the refrigerant retained in the refrigerant flow path 83 inside the evaporator 80 can be easily recovered.

[0111] [Modifications]

[0112] The embodiments disclosed this time should be considered in all respects as illustrative and non-restrictive. The scope of the present invention is indicated not by the above-mentioned embodiments but by the claims, and includes all modifications (variations) within the meaning and scope equivalent to the claims.

[0113] For example, in the first embodiment, the flow rate adjustment unit 60 is provided in the bypass flow path 75, but the present invention is not limited thereto. Figure 3As in the first modified example shown in the figure, the flow rate adjustment unit 60 is not provided in the bypass flow path 75. When the flow rate adjustment unit 60 is not provided in the bypass flow path 75, the flow rate of the refrigerant flowing into the evaporator 80 in the state where the evaporator 80 is connected and the distribution of the flow rate of the refrigerant flowing into the bypass flow path 75 can be adjusted by, for example, the pipe diameter and flow path length of the bypass flow path 75.

[0114] In addition, in the first embodiment, an example is shown in which the flow rate of the refrigerant flowing into the evaporator 80 is greater than the flow rate of the refrigerant flowing into the bypass flow path 75, but the present invention is not limited to this. For example, the flow rate of the refrigerant flowing into the evaporator 80 may be equal to the flow rate of the refrigerant flowing into the bypass flow path 75, or the flow rate of the refrigerant flowing into the evaporator 80 may be less than the flow rate of the refrigerant flowing into the bypass flow path 75.

[0115] In addition, in the first embodiment, the flow rate adjustment unit 60 is shown as an example of the throttle hole 61, but the present invention is not limited to this. Figure 4 As shown in the second modified example, the flow regulating unit 60 is a flow regulating valve 62. The flow regulating valve 62 is not particularly limited as long as it is a known valve such as a needle valve that can cut off and adjust the flow rate. In addition, the opening adjustment of the flow regulating valve 62 can also be performed manually or by computer control.

[0116] In the case where the flow regulating unit 60 is a flow regulating valve 62, it can also be configured to adjust the opening of the flow regulating valve 62 according to the cooling level of the cooling object as the heat source 81. For example, the opening of the flow regulating valve 62 in a state where the need for cooling the cooling object is low compared to the normal operation state can be made larger than the opening of the flow regulating valve 62 in the normal operation state. Thus, for example, the flow rate of the refrigerant flowing into the evaporator 80 can be made less than the flow rate of the refrigerant flowing into the bypass flow path 75. In addition, the pump 10 can also be configured not to adjust the refrigerant inflow amount of the refrigerant flowing into the evaporator 80, so that the burden of the pump 10 can be reduced. In addition, in the case where the flow rate of the refrigerant flowing into the evaporator 80 is desired to be less than the minimum flow rate of the pump 10, by adjusting the opening of the flow regulating valve 62 to be larger, the flow rate of the refrigerant flowing into the evaporator 80 can be adjusted to be smaller.

[0117] In addition, in the first embodiment, an example is shown in which the inlet-side opening and closing valve 51 and the outlet-side opening and closing valve 52 are provided, but the present invention is not limited to this. For example, both the inlet-side opening and closing valve 51 and the outlet-side opening and closing valve 52 may not be provided, and either the inlet-side opening and closing valve 51 or the outlet-side opening and closing valve 52 may not be provided.

[0118] In addition, in the first embodiment, the bypass flow path 75 is connected to the downstream side of the outlet side connection portion 42 and the upstream side of the condenser 20, but the present invention is not limited thereto. For example, the bypass flow path 75 may be directly connected to the condenser 20 instead of being connected to the flow path between the outlet side connection portion 42 and the condenser 20.

[0119] In addition, in the above-mentioned first embodiment, an example in which the storage section 30 is provided is shown, but the present invention is not limited to this. For example, the storage section 30 may not be provided.

[0120] In the first embodiment, the two-phase cooling system circulation device 100 is shown as a portable example, but the present invention is not limited thereto. For example, the two-phase cooling system circulation device 100 may be a fixed type.

[0121] In the first embodiment, the example in which the gas-liquid mixed refrigerant 2 flowing out of the evaporator 80 flows into the condenser 20 while the evaporator 80 is connected is shown, but the present invention is not limited thereto. For example, the refrigerant flowing out of the evaporator 80 may be in a gas phase single phase state.

[0122] In addition, in the above-mentioned second embodiment, an example is shown in which the detection unit 31 is a liquid level sensor, and the storage amount of the refrigerant stored in the storage unit 30 as the recovery amount of the refrigerant is detected by measuring the liquid level 3 of the liquid phase refrigerant 1 stored in the storage unit 30, but the present invention is not limited to this. For example, the detection unit may also be a differential pressure level sensor, and the storage amount of the refrigerant stored in the storage unit as the recovery amount of the refrigerant is detected by measuring the height of the liquid surface according to the difference between the pressure of the bottom surface of the storage unit and the pressure of the liquid surface. In addition, the detection unit may also be other known sensors.

[0123] In the second embodiment, the example in which the set liquid level 5 is set by the control unit 91 is shown, but the present invention is not limited to this. For example, the set liquid level 5 may be set by the user.

[0124] In addition, in the above-mentioned second embodiment, an example is shown in which the detection unit 31 detects the storage amount of the refrigerant stored in the storage unit 30 as the recovery amount of the refrigerant, but the present invention is not limited to this. For example, the circulation device for a two-phase cooling system can also be configured as follows: a detection unit is respectively provided near the inlet and the outlet of the storage unit, and the recovery amount of the refrigerant is detected based on the refrigerant flow rate detected by the detection unit near the inlet and the refrigerant flow rate detected by the detection unit near the outlet. In this case, when the difference between the refrigerant flow rate detected by the detection unit near the inlet and the refrigerant flow rate detected by the detection unit near the outlet becomes less than the threshold value, the control unit can also stop the operation of the pump and end the recovery process of the refrigerant. In addition, for example, the circulation device for a two-phase cooling system can also be configured as follows: a detection unit is provided between the outlet side opening and closing valve and the confluence portion, and the recovery amount of the refrigerant is detected based on the refrigerant flow rate detected by the detection unit.

[0125] In addition, in the above-mentioned second embodiment, an example is shown in which the control unit 91 stops the operation of the pump 10 and ends the recovery process of the refrigerant when the storage amount of the refrigerant detected by the detection unit 31 becomes greater than the preset storage amount, but the present invention is not limited to this. For example, as in the third modified example, when the change in the storage amount of the refrigerant detected by the detection unit 31 becomes less than the preset change, the control unit 91 stops the operation of the pump 10 and ends the recovery process of the refrigerant. In addition, the change in the storage amount of the refrigerant includes the change in the liquid level of the refrigerant 6 (see Fig. 9 ).

[0126] like Fig. 9 As shown, shortly after the refrigerant recovery state is reached and the inlet-side on-off valve 51 is closed, the change amount 6 per unit time of the liquid level of the liquid phase refrigerant 1 stored in the storage section 30 is the largest, and as time t passes, the change amount 6 per unit time of the liquid level of the liquid phase refrigerant 1 gradually decreases. Therefore, as the set change amount 7, the change amount per unit time of the liquid level of the liquid phase refrigerant 1 is preset. The set change amount 7 is a reference value that can be regarded as the refrigerant retained in the evaporator 80 having been recovered to the storage section 30. The set change amount 7 is preset by the user. The set change amount 7 is stored in the storage section 92.

[0127] In the refrigerant recovery state, the control unit 91 obtains the liquid level of the liquid phase refrigerant 1 stored in the storage unit 30 detected by the detection unit 31. The controller 91 obtains the change amount 6 of the liquid level of the liquid phase refrigerant 1 per unit time based on the liquid level of the liquid phase refrigerant 1 detected by the detection unit 31. Moreover, when the change amount 6 of the liquid level of the liquid phase refrigerant 1 becomes less than the preset change amount 7 (time t2), the control unit 91 controls the outlet side opening and closing valve 52 to close so as to prevent the refrigerant from flowing out of the outlet side opening and closing valve 52 to the outlet side connection part 42 side, and controls the operation of the pump 10 to stop the refrigerant recovery process.

[0128] According to the third modified example, as described above, in the refrigerant recovery state, when the change in the amount of refrigerant stored detected by the detection unit 31 when the refrigerant is circulated through the bypass flow path 75 without passing through the evaporator 80 becomes less than the preset change amount 7, the control unit 91 performs control to stop the operation of the pump 10 and end the refrigerant recovery process. Thus, for example, even if the total amount of refrigerant changes due to a decrease in refrigerant in the normal operation state of cooling the heat source 81, the control unit 91 can reliably detect that the refrigerant retained in the evaporator 80 has been recovered to the storage unit 30 based on the set change amount 7.

[0129] Furthermore, the control unit 91 may be configured to: when the liquid level 3 of the liquid phase refrigerant 1 detected by the detection unit 31 becomes equal to or higher than a preset liquid level 5 (see Figure 7 ), and when the change amount 6 of the liquid level of the liquid phase refrigerant 1 detected by the detection unit 31 becomes less than the preset set change amount 7, the operation of the pump 10 is stopped and the refrigerant recovery process is ended.

[0130] In addition, in the second embodiment described above, the control unit 91 is configured to perform control of the inlet-side on-off valve opening and closing mechanism 53 to close the inlet-side on-off valve 51, control of the outlet-side on-off valve opening and closing mechanism 54 to close the outlet-side on-off valve 52 based on the set storage amount, and control of stopping the operation of the pump 10 based on the set storage amount, but the present invention is not limited to this. For example, the user may perform any or all of the operations of closing the inlet-side on-off valve 51, closing the outlet-side on-off valve 52 based on the set storage amount, and stopping the operation of the pump 10 based on the set storage amount. In the case where the user performs all of the operations of closing the inlet-side on-off valve 51, closing the outlet-side on-off valve 52 based on the set storage amount, and stopping the operation of the pump 10 based on the set storage amount, the control unit may not be provided.

[0131] For example, the user may manually close the inlet-side on-off valve 51 before recovering the refrigerant from the evaporator 80. In addition, the user may manually close the outlet-side on-off valve 52 based on visual confirmation of the liquid level gauge. In addition, the user may perform an operation to stop the operation of the pump 10 based on visual confirmation of the liquid level gauge.

[0132] In addition, in the above-mentioned second embodiment and third modified example, the following example is shown: the control unit 91 is configured to control the outlet side on-off valve 52 to be in a closed state through the outlet side on-off valve opening and closing mechanism 54 and to stop the operation of the pump 10 and end the refrigerant recovery process when the storage amount of the refrigerant detected by the detection unit 31 becomes a preset storage amount or more, or when the change amount of the storage amount of the refrigerant detected by the detection unit 31 becomes less than the set change amount, but the present invention is not limited to this. For example, as in the fourth modified example, the circulation device 300 for the two-phase cooling system may also include a notification unit 93, and the control unit 91 may be configured to notify through the notification unit 93 that the storage amount of the refrigerant detected by the detection unit 31 has become more than the set storage amount, or that the change amount of the storage amount of the refrigerant detected by the detection unit 31 has become less than the set change amount. Thus, the user can recognize that the storage amount of the refrigerant detected by the detection unit 31 becomes greater than the set storage amount, or the change in the storage amount of the refrigerant detected by the detection unit 31 becomes less than the set change amount. Therefore, the user can quickly execute the operation of closing the outlet side opening and closing valve 52 and stopping the operation of the pump 10.

[0133] Then, when the notification unit 93 notifies the user of the above, the user performs an operation to close the outlet-side on-off valve 52 and also performs an operation to stop the operation of the pump 10 .

[0134] In this case, the notification unit 93 may include the display unit 94, and when the storage amount of the refrigerant detected by the detection unit 31 becomes greater than a preset storage amount, or when the change in the storage amount of the refrigerant detected by the detection unit 31 becomes less than the set change, the control unit 91 controls the display unit 94 to display a notification to the effect that "the refrigerant is recovered". In addition, the notification unit 93 may include the sound output unit 95 instead of the display unit 94, or include the display unit 94 and the sound output unit 95, and when the storage amount of the refrigerant detected by the detection unit 31 becomes greater than a preset storage amount, or when the change in the storage amount of the refrigerant detected by the detection unit 31 becomes less than the set change, the control unit 91 controls the sound output unit 95 to broadcast the meaning that "the refrigerant is recovered".

[0135] In addition, in the first embodiment and the second embodiment, an example is shown in which the inlet-side opening and closing valve 51, the outlet-side opening and closing valve 52, and the flow rate adjustment unit 60 are provided, but the present invention is not limited to this. Fig.12 As shown in the fifth modification, a first three-way valve 98 is provided at the branch portion 76 and a second three-way valve 99 is provided at the confluence portion 77, instead of the inlet-side on-off valve 51, the outlet-side on-off valve 52, and the flow rate adjustment portion 60. In this case, the control portion 91 may be configured to switch the first three-way valve 98 and the second three-way valve 99, or the user may switch the first three-way valve 98 and the second three-way valve 99.

[0136] [Way]

[0137] It will be understood by those skilled in the art that the above-described exemplary embodiments are specific examples of the following aspects.

[0138] (Item 1)

[0139] A circulation device for a two-phase cooling system, constituting a two-phase cooling system in which a refrigerant circulates by connecting a detachable evaporator, the circulation device for a two-phase cooling system comprising:

[0140] a pump that delivers the refrigerant;

[0141] an inlet-side connection portion and an outlet-side connection portion, wherein the inlet-side connection portion and the outlet-side connection portion are arranged on the downstream side of the pump, the inlet-side connection portion is connected to the inlet of the refrigerant in the evaporator, and the outlet-side connection portion is connected to the outlet of the refrigerant in the evaporator;

[0142] a condenser disposed on a downstream side of the outlet-side connecting portion and configured to cool the refrigerant; and

[0143] a bypass flow path branched off at the downstream side of the pump and the upstream side of the inlet-side connection portion, for allowing the refrigerant to flow into the condenser without passing through the inlet-side connection portion and the outlet-side connection portion,

[0144] Here, at least in a state where the evaporator is not connected to the inlet-side connection portion and the outlet-side connection portion, the refrigerant is circulated through the bypass flow path without passing through the inlet-side connection portion and the outlet-side connection portion.

[0145] (Item 2)

[0146] The circulation device for a two-phase cooling system according to item 1, wherein:

[0147] In a normal operation state in which the evaporator is connected to the inlet-side connection portion and the outlet-side connection portion, a part of the refrigerant circulates through the evaporator, and the rest of the refrigerant circulates through the bypass flow path.

[0148] (Item 3)

[0149] The circulation device for a two-phase cooling system according to item 1 or 2,

[0150] A flow rate adjustment unit is further provided, and the flow rate adjustment unit is provided in the bypass flow path.

[0151] (Item 4)

[0152] The circulation device for a two-phase cooling system according to item 3, wherein:

[0153] The flow rate adjustment unit is an orifice that adjusts the flow rate of the refrigerant flowing in the bypass flow channel.

[0154] (Item 5)

[0155] The circulation device for a two-phase cooling system according to item 3, wherein:

[0156] The flow rate adjustment unit is a flow rate adjustment valve that adjusts the flow rate of the refrigerant flowing through the bypass flow path.

[0157] (Item 6)

[0158] The circulation device for a two-phase cooling system according to any one of items 1 to 5, wherein:

[0159] The condenser is configured to condense and cool a gas phase refrigerant included in a gas-liquid mixed refrigerant in the refrigerant, or to cool a liquid phase refrigerant in the refrigerant, by a cooling liquid flowing in from the outside.

[0160] (Item 7)

[0161] The circulation device for a two-phase cooling system according to any one of items 1 to 6, wherein:

[0162] The bypass flow path branches off on the downstream side of the pump and the upstream side of the inlet-side connection portion, and is connected to the downstream side of the outlet-side connection portion and the upstream side of the condenser.

[0163] (Item 8)

[0164] The two-phase cooling system circulation device according to item 7 further comprises:

[0165] an inlet-side opening and closing valve provided between a branch portion from which the bypass flow path branches off on the downstream side of the pump and the inlet-side connecting portion, for opening and closing the flow path of the refrigerant; and

[0166] An outlet-side opening and closing valve is provided between the outlet-side connection portion and a connection portion connected to the bypass flow path on the downstream side of the outlet-side connection portion, and is used to open and close the flow path of the refrigerant.

[0167] (Item 9)

[0168] The circulation device for a two-phase cooling system according to any one of items 1 to 8, wherein:

[0169] A storage unit is further provided on the downstream side of the condenser and the upstream side of the pump.

[0170] (Item 10)

[0171] The circulation device for a two-phase cooling system according to any one of items 1 to 9, wherein:

[0172] In a state where the evaporator is connected to the inlet-side connection portion and the outlet-side connection portion, the gas-liquid mixed refrigerant flowing out of the evaporator flows into the condenser.

[0173] (Item 11)

[0174] The circulation device for a two-phase cooling system according to item 1,

[0175] The inlet-side opening and closing valve is provided between a branch portion of the bypass flow path branched off on the downstream side of the pump and the inlet-side connecting portion, and is used to open and close the flow path of the refrigerant.

[0176] When recovering the refrigerant from the evaporator, in a refrigerant recovery state in which the evaporator is connected to the inlet-side connection portion and the outlet-side connection portion and the inlet-side opening and closing valve is closed, the refrigerant is circulated through the bypass flow path instead of through the evaporator, and the refrigerant in the evaporator is guided to the condenser.

[0177] (Item 12)

[0178] The two-phase cooling system circulation device according to item 11 further comprises:

[0179] a detection unit configured to detect the amount of recovered refrigerant; and

[0180] A control unit stops the operation of the pump and ends the recovery process of the refrigerant based on the detection result of the detection unit.

[0181] (Item 13)

[0182] The circulation device for a two-phase cooling system according to item 12,

[0183] A storage unit is further provided, the storage unit being provided on the downstream side of the condenser and the upstream side of the pump,

[0184] The detection unit detects a storage amount of the refrigerant stored in the storage unit as a recovery amount of the refrigerant.

[0185] (Item 14)

[0186] The circulation device for a two-phase cooling system according to item 13, wherein:

[0187] In the refrigerant recovery state, when the storage amount of the refrigerant detected by the detection unit when the refrigerant is circulated through the bypass flow path instead of through the evaporator becomes greater than a preset storage amount, the control unit stops the operation of the pump and ends the recovery process of the refrigerant.

[0188] (Item 15)

[0189] The circulation device for a two-phase cooling system according to item 13, wherein:

[0190] In the refrigerant recovery state, when the change in the storage amount of the refrigerant detected by the detection unit when the refrigerant is circulated through the bypass flow path instead of through the evaporator becomes less than a preset change, the control unit stops the operation of the pump and ends the recovery process of the refrigerant.

[0191] (Item 16)

[0192] The circulation device for a two-phase cooling system according to item 14 or 15,

[0193] A notification unit is further provided for notifying that the storage amount of the refrigerant detected by the detection unit has become equal to or larger than the set storage amount, or that a change in the storage amount of the refrigerant detected by the detection unit has become equal to or smaller than the set change.

[0194] (Item 17)

[0195] The circulation device for a two-phase cooling system according to item 13, wherein:

[0196] The refrigerant further comprises an outlet-side opening and closing valve, which is provided between the outlet-side connecting portion and a connecting portion connected to the bypass flow path on the downstream side of the outlet-side connecting portion, and is used to open and close the flow path of the refrigerant.

[0197] The control unit performs control to close the outlet-side on-off valve based on the detection result of the detection unit so as to prevent the refrigerant from flowing out from the outlet-side on-off valve to the outlet-side connecting portion.

[0198] (Item 18)

[0199] A refrigerant circulation method is a refrigerant circulation method in a two-phase cooling system circulation device, wherein the two-phase cooling system circulation device constitutes a two-phase cooling system that circulates refrigerant by connecting a detachable evaporator, and the refrigerant circulation method comprises the following steps:

[0200] At least in a state where the evaporator is not connected to an inlet-side connection portion connected to an inlet of the refrigerant in the evaporator and an outlet-side connection portion connected to an outlet of the refrigerant in the evaporator, the refrigerant is caused to flow through a bypass flow path for flowing the refrigerant without passing through the inlet-side connection portion and the outlet-side connection portion; and

[0201] The refrigerant flowing through the bypass flow path and into the condenser is cooled.

[0202] (Item 19)

[0203] The refrigerant cycle method according to item 18 further comprises the following steps:

[0204] When recovering the refrigerant from the evaporator, in a refrigerant recovery state in which the evaporator is connected to the inlet-side connection portion and the outlet-side connection portion and an inlet-side on-off valve provided between a branch portion from which the bypass flow path is branched and the inlet-side connection portion is closed, the refrigerant is circulated through the bypass flow path without passing through the evaporator, and the refrigerant of the evaporator is guided to the condenser; and

[0205] Based on the detection result of the recovery amount of the refrigerant, the circulation of the refrigerant is stopped and the recovery process of the refrigerant is ended.

[0206] Description of Reference Numerals

[0207] 2: gas-liquid mixed refrigerant; 5: set liquid level (set storage amount); 7: set change amount; 10: pump; 20: condenser; 23: coolant; 30: storage unit; 31: detection unit; 41: inlet side connection unit; 42: outlet side connection unit; 51: inlet side opening and closing valve; 52: outlet side opening and closing valve; 60: flow adjustment unit; 61: throttle hole; 62: flow adjustment valve; 75: bypass flow path; 80: evaporator; 91: control unit; 93: notification unit; 100, 300: circulation device for two-phase cooling system; 200, 400: two-phase cooling system.

Claims

1. A circulation device for a two-phase cooling system, constituting a two-phase cooling system in which a refrigerant circulates by connecting a detachable evaporator, the circulation device for a two-phase cooling system comprising: a pump that delivers the refrigerant; an inlet-side connection portion and an outlet-side connection portion, wherein the inlet-side connection portion and the outlet-side connection portion are arranged on the downstream side of the pump, the inlet-side connection portion is connected to the inlet of the refrigerant in the evaporator, and the outlet-side connection portion is connected to the outlet of the refrigerant in the evaporator; a condenser, which is disposed at a downstream side of the outlet-side connecting portion and is used to cool the refrigerant; as well as a bypass flow path branched off at the downstream side of the pump and the upstream side of the inlet-side connection portion, for allowing the refrigerant to flow into the condenser without passing through the inlet-side connection portion and the outlet-side connection portion, Here, at least in a state where the evaporator is not connected to the inlet-side connection portion and the outlet-side connection portion, the refrigerant is circulated through the bypass flow path without passing through the inlet-side connection portion and the outlet-side connection portion.

2. The circulation device for a two-phase cooling system according to claim 1, wherein: In a normal operation state in which the evaporator is connected to the inlet-side connection portion and the outlet-side connection portion, a part of the refrigerant circulates through the evaporator, and the rest of the refrigerant circulates through the bypass flow path.

3. The circulation device for a two-phase cooling system according to claim 1 or 2, wherein: A flow rate adjustment unit is further provided, and the flow rate adjustment unit is provided in the bypass flow path.

4. The circulation device for a two-phase cooling system according to claim 3, wherein: The flow rate adjustment unit is an orifice that adjusts the flow rate of the refrigerant flowing in the bypass flow channel.

5. The circulation device for a two-phase cooling system according to claim 3, wherein: The flow rate adjustment unit is a flow rate adjustment valve that adjusts the flow rate of the refrigerant flowing through the bypass flow path.

6. The circulation device for a two-phase cooling system according to claim 1, wherein: The condenser is configured to condense and cool a gas phase refrigerant included in a gas-liquid mixed refrigerant in the refrigerant, or to cool a liquid phase refrigerant in the refrigerant, by a cooling liquid flowing in from the outside.

7. The circulation device for a two-phase cooling system according to claim 1, wherein: The bypass flow path branches off on the downstream side of the pump and the upstream side of the inlet-side connection portion, and is connected to the downstream side of the outlet-side connection portion and the upstream side of the condenser.

8. The circulation device for a two-phase cooling system according to claim 7, wherein: Also available: an inlet-side opening and closing valve provided between a branch portion from which the bypass flow path branches off on the downstream side of the pump and the inlet-side connecting portion, for opening and closing the flow path of the refrigerant; and An outlet-side opening and closing valve is provided between the outlet-side connection portion and a connection portion connected to the bypass flow path on the downstream side of the outlet-side connection portion, and is used to open and close the flow path of the refrigerant.

9. The circulation device for a two-phase cooling system according to claim 1, wherein: A storage unit is further provided on the downstream side of the condenser and the upstream side of the pump.

10. The circulation device for a two-phase cooling system according to claim 1, wherein: In a state where the evaporator is connected to the inlet-side connection portion and the outlet-side connection portion, the gas-liquid mixed refrigerant flowing out of the evaporator flows into the condenser.

11. The circulation device for a two-phase cooling system according to claim 1, wherein: The inlet-side opening and closing valve is provided between a branch portion of the bypass flow path branched off on the downstream side of the pump and the inlet-side connecting portion, and is used to open and close the flow path of the refrigerant. When recovering the refrigerant from the evaporator, in a refrigerant recovery state in which the evaporator is connected to the inlet-side connection portion and the outlet-side connection portion and the inlet-side opening and closing valve is closed, the refrigerant is circulated through the bypass flow path instead of through the evaporator, and the refrigerant in the evaporator is guided to the condenser.

12. The circulation device for a two-phase cooling system according to claim 11, wherein: Also available: a detection unit configured to detect the amount of recovered refrigerant; and A control unit stops the operation of the pump and ends the recovery process of the refrigerant based on the detection result of the detection unit.

13. The circulation device for a two-phase cooling system according to claim 12, wherein: A storage unit is further provided, the storage unit being provided on the downstream side of the condenser and the upstream side of the pump, The detection unit detects a storage amount of the refrigerant stored in the storage unit as a recovery amount of the refrigerant.

14. The circulation device for a two-phase cooling system according to claim 13, wherein: In the refrigerant recovery state, when the storage amount of the refrigerant detected by the detection unit when the refrigerant is circulated through the bypass flow path instead of through the evaporator becomes greater than a preset storage amount, the control unit stops the operation of the pump and ends the recovery process of the refrigerant.

15. The circulation device for a two-phase cooling system according to claim 13, wherein: In the refrigerant recovery state, when the change in the storage amount of the refrigerant detected by the detection unit when the refrigerant is circulated through the bypass flow path instead of through the evaporator becomes less than a preset change, the control unit stops the operation of the pump and ends the recovery process of the refrigerant.

16. The circulation device for a two-phase cooling system according to claim 14 or 15, wherein: A notification unit is further provided for notifying that the storage amount of the refrigerant detected by the detection unit has become equal to or larger than the set storage amount, or that a change in the storage amount of the refrigerant detected by the detection unit has become equal to or smaller than the set change.

17. The circulation device for a two-phase cooling system according to claim 13, wherein: The refrigerant further comprises an outlet-side opening and closing valve, which is provided between the outlet-side connecting portion and a connecting portion connected to the bypass flow path on the downstream side of the outlet-side connecting portion, and is used to open and close the flow path of the refrigerant. The control unit performs control to close the outlet-side on-off valve based on the detection result of the detection unit so as to prevent the refrigerant from flowing out from the outlet-side on-off valve to the outlet-side connecting portion.

18. A refrigerant circulation method, which is a refrigerant circulation method in a two-phase cooling system circulation device, wherein the two-phase cooling system circulation device constitutes a two-phase cooling system that circulates refrigerant by connecting a detachable evaporator, and the refrigerant circulation method comprises the following steps: At least in a state where the evaporator is not connected to an inlet-side connection portion connected to an inlet of the refrigerant in the evaporator and an outlet-side connection portion connected to an outlet of the refrigerant in the evaporator, the refrigerant is caused to flow through a bypass flow path for flowing the refrigerant without passing through the inlet-side connection portion and the outlet-side connection portion; and The refrigerant flowing through the bypass flow path and into the condenser is cooled.

19. The refrigerant cycle method according to claim 18, further comprising the following steps: When recovering the refrigerant from the evaporator, in a refrigerant recovery state in which the evaporator is connected to the inlet-side connection portion and the outlet-side connection portion, and an inlet-side on-off valve provided between a branch portion from which the bypass flow path is branched and the inlet-side connection portion is closed, the refrigerant is circulated through the bypass flow path instead of through the evaporator, and the refrigerant of the evaporator is guided to the condenser; as well as Based on the detection result of the recovery amount of the refrigerant, the circulation of the refrigerant is stopped and the recovery process of the refrigerant is ended.

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