Method for adjusting heat transport device

Abstract

A method for adjusting a cooling device (100) comprises: a step for preparing a cooling device in which the volume of a gas phase portion (1a) of a tank (1) for storing a refrigerant (101) is changed to adjust the pressure of an inert gas (6) sealed in the gas phase portion of the tank, thereby adjusting the evaporation temperature of the refrigerant; and a step for adjusting the rate of change in the evaporation temperature of the refrigerant with respect to a charge in the volume of the gas phase portion of the tank, by adjusting the amount of the inert gas or the amount of the refrigerant to be filled in the cooling device.

Description

Method for adjusting a heat transport device

[0001] The present invention relates to a method for adjusting a heat transport device.

[0002] A heat transport device including a tank has been disclosed in WO 2023 / 074049, for example.

[0003] International Publication No. 2023 / 074049 discloses a cooling device (heat transport device) including a tank for storing a refrigerant, an evaporator for evaporating the refrigerant sent from the tank to cool a cooling target, and a condenser for condensing the refrigerant evaporated by the evaporator. In this cooling device, a gas is sealed in a gas phase of the tank, and a bellows is provided for changing the volume of the gas phase. In this cooling device, the bellows changes the volume of the gas phase of the tank, thereby adjusting the pressure of the inert gas sealed in the gas phase of the tank and adjusting the evaporation temperature of the refrigerant.

[0004] International Publication No. 2023 / 074049

[0005] In the cooling device described in WO 2023 / 074049, the volume of the gas phase of the tank is changed using a bellows to adjust the pressure of the inert gas sealed in the gas phase of the tank, thereby adjusting the evaporation temperature of the refrigerant. However, no consideration is given to the rate of change of the evaporation temperature of the refrigerant. Therefore, it is difficult to perform effective temperature control when the rate of change of the evaporation temperature of the refrigerant is important. Therefore, it is desirable to enable effective temperature control when the rate of change of the evaporation temperature of the refrigerant is important.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a method for adjusting a heat transport device that can perform effective temperature control when the rate of change of the evaporation temperature of the refrigerant is important.

[0007] In order to achieve the above object, in one aspect of the present invention, a method for adjusting a heat transport device includes the steps of preparing a heat transport device that adjusts the evaporation temperature of the refrigerant by changing the volume of the gas phase of the tank, thereby adjusting the pressure of an inert gas sealed in the gas phase of the tank, and adjusting the rate of change of the evaporation temperature of the refrigerant relative to the change in volume of the gas phase of the tank by adjusting the amount of inert gas filled into the heat transport device.

[0008] In one aspect of the heat transport device adjustment method, a step of adjusting the rate of change of the refrigerant evaporation temperature relative to the volume change of the gas phase of the tank by adjusting the amount of inert gas filled into the heat transport device is provided. This allows the rate of change of the refrigerant evaporation temperature to be adjusted to a desired rate. As a result, for example, when the heat transport device is used in an application where a rapid increase in the refrigerant evaporation temperature is important, the rate of increase in the refrigerant evaporation temperature can be increased to allow the refrigerant evaporation temperature to be increased quickly. Also, for example, when the heat transport device is used in an application where a rapid decrease in the refrigerant evaporation temperature is important, the rate of decrease in the refrigerant evaporation temperature can be increased to allow the refrigerant evaporation temperature to be decreased quickly. This allows effective temperature control when a high priority is placed on the rate of change of the refrigerant evaporation temperature.

[0009] FIG. 1 is a schematic diagram showing a heat transport device according to an embodiment; FIG. 2 is a diagram for explaining a volume change in a gas phase part of a tank caused by a volume change part of a heat transport device according to an embodiment; FIG. 3 is a schematic diagram showing a configuration for filling an inert gas and a refrigerant into a heat transport device according to an embodiment; FIG. 4 is a flowchart for explaining a method for adjusting a heat transport device according to an embodiment; FIG. 5 is a graph (1) for explaining a rate of change in evaporation temperature of a refrigerant according to an embodiment; FIG. 6 is a graph (2) for explaining a rate of change in evaporation temperature of a refrigerant according to an embodiment; FIG. 7 is a schematic diagram for explaining the state of a refrigerant in a heat transport device according to an embodiment with and without heat input; and FIG. 8 is a schematic diagram showing a configuration for filling an inert gas and a refrigerant into a heat transport device according to a modified embodiment.

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0011] First, the configuration of a heat transport device 100 to which an adjustment method for a heat transport device 100 according to one embodiment is applied will be described with reference to FIGS. 1 and 2. FIG.

[0012] (Configuration of the Heat Transport Device) As shown in Fig. 1, the heat transport device 100 is a heat transport device that performs two-phase heat exchange (cooling or heating) utilizing the phase change that occurs when a refrigerant 101 changes between a liquid and a gas. Specifically, the heat transport device 100 includes a tank 1, a pump 2, a heat exchanger 3, and a condenser 4. The refrigerant 101 is not particularly limited, but for example, carbon dioxide, a natural refrigerant, can be used. The heat transport device 100 can also be applied to heat exchange in, for example, space equipment and machine part manufacturing equipment, but is not particularly limited thereto.

[0013] The tank 1 is a container that stores a liquid refrigerant 101. The tank 1 is also connected to the pump 2 via a pipe 5a.

[0014] The pump 2 is configured to suck the liquid refrigerant 101 stored in the tank 1 and discharge the sucked liquid refrigerant 101 toward the heat exchanger 3. There are no particular limitations on the type of pump 2, but for example, a positive displacement pump or a centrifugal pump can be used. The pump 2 is also connected to the heat exchanger 3 via a pipe 5b.

[0015] The heat exchanger 3 functions as an evaporator that cools the target 200 by evaporating the liquid refrigerant 101 discharged from the pump 2. The target 200 is, for example, a heat-generating body such as an electronic device. The heat exchanger 3 functions as a heat exchanger that exchanges heat between the target 200 and the refrigerant 101. That is, the heat exchanger 3 is configured to receive heat from the target 200 and evaporate the refrigerant 101. The heat exchanger 3 is also connected to the condenser 4 via a pipe 5c. In the pipe 5c, the refrigerant 101 is in a gas-liquid two-phase flow state in which the liquid refrigerant 101 and the gas refrigerant 101 are mixed.

[0016] Furthermore, a preheater 3a is provided upstream of the heat exchanger 3. The preheater 3a is configured to preheat the liquid refrigerant 101 that flows into the heat exchanger 3. The preheater 3a is configured to preheat the liquid refrigerant 101 so as to evaporate a portion of the refrigerant 101 in the heat exchanger 3.

[0017] The condenser 4 is configured to condense the gaseous refrigerant 101 evaporated in the heat exchanger 3. The condenser 4 functions as a heat exchanger that exchanges heat between the brine 4b of the refrigerator 4a and the refrigerant 101. That is, the condenser 4 is configured to transfer heat to the brine 4b and condense the refrigerant 101. The condenser 4 is also connected to the tank 1 via a pipe 5d.

[0018] The heat transport device 100 functions as a cooling device that cools the object 200 by repeating a circulation cycle in which the refrigerant 101 sent out from the tank 1 flows through the pump 2, the heat exchanger 3, and the condenser 4 in that order, and then returns to the tank 1.

[0019] Furthermore, since the heat transport device 100 is provided with the preheater 3a, it can function not only as a cooling device but also as a heating device that heats the target 200. In this case, the heat exchanger 3 functions as a condenser that condenses the gaseous refrigerant 101 evaporated in the preheater 3a and heats the target 200. In other words, the heat exchanger 3 is configured to provide heat to the target 200 and condense the refrigerant 101.

[0020] The heat transport device 100 is configured to adjust the pressure of the refrigerant 101, thereby adjusting the evaporation temperature of the refrigerant 101 and thereby adjusting the temperature of the target 200. The heat transport device 100 is configured to adjust the pressure of an inert gas 6 (described later) sealed in the gas phase portion 1a of the tank 1 by changing the volume of the gas phase portion 1a of the tank 1 that stores the refrigerant 101, thereby adjusting the evaporation temperature of the refrigerant 101.

[0021] As shown in FIGS. 1 and 2 , the gas phase portion 1a of the tank 1 is filled with an inert gas 6, and is provided with a volume change unit 7 that changes the volume of the gas phase portion 1a to change the pressure of the inert gas 6 and thereby change the pressure of the refrigerant 101, thereby adjusting the evaporation temperature of the refrigerant 101. By filling the gas phase portion 1a of the tank 1 with the inert gas 6, the pressure (partial pressure) of the inert gas 6 filled in the gas phase portion 1a of the tank 1 can pressurize the refrigerant 101 and increase the pressure of the refrigerant 101. This reduces the amount of pressure increase (pressure increase) of the refrigerant 101 by the pump 2 by the pressure (partial pressure) of the inert gas 6. As a result, the pump 2 can be made smaller. Furthermore, by providing the volume change unit 7 in the gas phase portion 1a of the tank 1, the amount of pressurization of the refrigerant 101 by the inert gas 6 can be changed to adjust the evaporation temperature of the refrigerant 101.

[0022] The inert gas 6 is an inert gas that does not react with the refrigerant 101 and does not condense due to the volume change of the gas phase portion 1a caused by the volume change portion 7. The evaporation temperature of the inert gas 6 is lower than that of the refrigerant 101 at the same pressure. The inert gas 6 is, for example, nitrogen. The volume change portion 7 is provided on the ceiling portion 1c of the tank 1, avoiding the liquid phase portion 1b in which the liquid refrigerant 101 is stored. In FIG. 2, for ease of understanding, the inert gas 6 present in the gas phase portion 1a is indicated by a hatched circle, and the gas refrigerant 101 present in the gas phase portion 1a is indicated by a white circle.

[0023] The volume changing portion 7 is configured to change its volume by expanding and contracting due to the volume changing gas 8, thereby changing the volume of the gas phase portion 1a. Specifically, the volume changing portion 7 is a metal bellows. The volume changing portion 7 is configured as a hollow tubular member having a wavy (bellows-shaped) tubular wall with repeated mountain folds and valley folds. One end of the volume changing portion 7, which is a fixed end, is attached to the ceiling portion 1c of the tank 1, and the other end, which is a movable end, is provided so as to be movable along the vertical direction within the tank 1. The interior of the volume changing portion 7 and the interior of the tank 1 are separated by the tubular wall and the other end to prevent fluid (liquid and gas) from passing through them.

[0024] The volume changing unit 7 is configured to change the volume of the gas phase portion 1a by expanding and deforming to increase its volume when the volume changing gas 8 is supplied from the gas source 9 to the interior of the volume changing unit 7. The volume changing unit 7 is also configured to change the volume of the gas phase portion 1a by contracting and deforming to decrease its volume when the volume changing gas 8 is discharged from the interior of the volume changing unit 7 to the exterior, thereby changing the volume of the gas phase portion 1a by increasing its volume. The volume changing unit 7 is configured to expand and contract within the range of the gas phase portion 1a (a range that does not come into contact with the liquid surface of the liquid refrigerant 101). The maximum volume of the volume changing unit 7 (the volume at maximum expansion) is smaller than the volume of the tank 1. The volume changing gas 8 is, for example, nitrogen.

[0025] Here, the volume of the gas phase portion 1a when the volume change portion 7 is contracted is V Ａ The pressure (partial pressure) of the inert gas 6 in the gas phase portion 1a at this time is P Ａ In addition, the volume of the gas phase portion 1a when the volume change portion 7 is expanded is V Ｂ The pressure (partial pressure) of the inert gas 6 in the gas phase portion 1a at this time is P Ｂ In addition, since the amount of inert gas 6 in the gas phase portion 1a is constant, according to Boyle's law, P Ａ ×V Ａ =P Ｂ ×V Ｂ Therefore, when the volume change portion 7 changes from a contracted state to an expanded state, the volume of the gas phase portion 1a changes to V Ａ From V Ｂ When the pressure (partial pressure) of the inert gas 6 decreases to P Ａ From P Ｂ When the volume change portion 7 changes from a contracted state to an expanded state, the refrigerant 101a in the gas phase portion 1a condenses and changes into the liquid refrigerant 101. Therefore, the pressure (partial pressure) of the refrigerant 101a does not change.

[0026] In addition, the pressure (partial pressure) of the inert gas 6 is P Ａ From P ＢIncreasing the pressure (partial pressure) of the inert gas 6 to P Ａ From P Ｂ When the pressure (partial pressure) of the inert gas 6 is increased to P, the pressure of the refrigerant 101 can be increased and the evaporation temperature of the refrigerant 101, which changes in response to the pressure, can be increased. Ｂ From P Ａ When the temperature is reduced to 0.5°C, the evaporation temperature of the refrigerant 101 can be reduced.

[0027] (Configuration for Charging Inert Gas and Refrigerant) A configuration for charging the heat transport device 100 with the inert gas 6 and the refrigerant 101 will be described with reference to FIG.

[0028] As shown in FIG. 3, the heat transport device 100 is connected to a refrigerant source 111 , an inert gas source 112 , and a vacuum pump 113 via a manifold 114 .

[0029] The refrigerant source 111 supplies the refrigerant 101 to the heat transport device 100. The refrigerant source 111 is, for example, a cylinder filled with the refrigerant 101. A flow control valve 115 is provided between the refrigerant source 111 and the manifold 114. The flow control valve 115 adjusts the flow rate of the refrigerant 101 supplied from the refrigerant source 111 to the heat transport device 100 by adjusting its opening degree.

[0030] The inert gas source 112 supplies the inert gas 6 to the heat transport device 100. The inert gas source 112 is, for example, a cylinder filled with the inert gas 6. A flow rate control valve 116 is provided between the inert gas source 112 and the manifold 114. The flow rate control valve 116 adjusts the flow rate of the inert gas 6 supplied from the inert gas source 112 to the heat transport device 100 by adjusting its opening degree.

[0031] The vacuum pump 113 is a pump for evacuating the heat transport device 100. In this specification, the term "vacuum" does not mean an absolute vacuum, but rather refers to a state in which a specific space is filled with gas at a pressure lower than atmospheric pressure.

[0032] The manifold 114 switches the connection destination of the heat transport device 100. Specifically, the manifold 114 has a valve 114a that opens and closes a flow path connecting the vacuum pump 113 and the heat transport device 100, and a valve 114b that opens and closes a flow path connecting either the refrigerant source 111 or the inert gas source 112 to the heat transport device 100. By operating the valves 114a and 114b, the manifold 114 switches the connection destination of the heat transport device 100 to either the refrigerant source 111, the inert gas source 112, or the vacuum pump 113. This makes it possible to fill the heat transport device 100 with the refrigerant 101, fill the heat transport device 100 with the inert gas 6, and evacuate the heat transport device 100.

[0033] (Method of Adjusting the Heat Transport Device) A method of adjusting the heat transport device 100 will be described based on a flowchart, mainly with reference to FIG.

[0034] 4 , the method for adjusting the heat transport device 100 includes a step (901) of preparing the heat transport device 100, which adjusts the pressure of the inert gas 6 sealed in the gas phase 1a of the tank 1 by changing the volume of the gas phase 1a of the tank 1 that stores the refrigerant 101, thereby adjusting the evaporation temperature of the refrigerant 101, and a step (902) of adjusting the rate of change in the evaporation temperature of the refrigerant 101 relative to the volume change of the gas phase 1a of the tank 1 by adjusting the amount of the inert gas 6 or the amount of the refrigerant 101 filled into the heat transport device 100. The method for adjusting the heat transport device 100 also includes a step (903) of filling the heat transport device 100 with the inert gas 6 and a step (904) of filling the heat transport device 100 with the refrigerant 101.

[0035] <Step of Preparing a Heat Transport Device> In step 901, the heat transport device 100 is prepared. Specifically, the heat transport device 100 is prepared in a state where it is not filled with the inert gas 6 and the refrigerant 101. The tank 1, the pump 2, the heat exchanger 3, the condenser 4, and the pipes 5a to 5d are not filled with the inert gas 6 and the refrigerant 101.

[0036] <Step of Adjusting the Rate of Change of the Evaporation Temperature of the Refrigerant> In step 902, the rate of change of the evaporation temperature of the refrigerant 101 relative to the volume change of the gas phase 1a of the tank 1 is adjusted by adjusting the amount of inert gas 6 or the amount of refrigerant 101 filled into the heat transport device 100. Specifically, when the rate of increase in the evaporation temperature of the refrigerant 101 relative to the volume change of the gas phase 1a of the tank 1 is increased, the amount of inert gas 6 or the amount of refrigerant 101 filled into the heat transport device 100 is increased. On the other hand, when the rate of decrease in the evaporation temperature of the refrigerant 101 relative to the volume change of the gas phase 1a of the tank 1 is increased, the amount of inert gas 6 or the amount of refrigerant 101 filled into the heat transport device 100 is decreased. Note that the processing of step 902 is performed by an operator.

[0037] Increasing the amount of inert gas 6 charged into the heat transport device 100 increases the amount of inert gas 6 relative to the volume of the gas phase portion 1a in the tank 1, thereby increasing the pressure (partial pressure) of the inert gas 6 in the gas phase portion 1a in the tank 1. Furthermore, increasing the amount of refrigerant 101 charged into the heat transport device 100 reduces the volume of the gas phase portion 1a in the tank 1, thereby increasing the amount of inert gas 6 relative to the volume of the gas phase portion 1a in the tank 1. Therefore, the pressure (partial pressure) of the inert gas 6 in the gas phase portion 1a in the tank 1 can be increased.

[0038] Similarly, by reducing the amount of inert gas 6 charged into the heat transport device 100, the amount of inert gas 6 relative to the volume of the gas phase portion 1a in the tank 1 can be reduced, thereby reducing the pressure (partial pressure) of the inert gas 6 in the gas phase portion 1a in the tank 1. Furthermore, by reducing the amount of refrigerant 101 charged into the heat transport device 100, the volume of the gas phase portion 1a in the tank 1 can be increased, thereby reducing the amount of inert gas 6 relative to the volume of the gas phase portion 1a in the tank 1. Therefore, the pressure (partial pressure) of the inert gas 6 in the gas phase portion 1a in the tank 1 can be reduced. Note that either the amount of inert gas 6 or the amount of refrigerant 101 may be kept constant, and only the other of the amount of inert gas 6 or the amount of refrigerant 101 may be adjusted, or both the amount of inert gas 6 and the amount of refrigerant 101 may be adjusted.

[0039] 5 and 6 are graphs illustrating the rate of change of the evaporation temperature of the refrigerant 101. In the graphs of FIGS. 5 and 6, the horizontal axis represents the volume of the gas phase portion 1a of the tank 1, and the vertical axis represents the pressure (partial pressure) of the inert gas 6. As described above, the pressure (partial pressure) of the inert gas 6 corresponds to the evaporation temperature of the refrigerant 101. The higher the pressure (partial pressure) of the inert gas 6, the higher the evaporation temperature of the refrigerant 101. In addition, in the graphs of FIGS. 5 and 6, the solid lines represent examples in which the amount of the inert gas 6 or the amount of the refrigerant 101 filled into the heat transport device 100 is small, resulting in a low pressure (partial pressure) of the inert gas 6. Specifically, the solid lines represent the change in the pressure (partial pressure) of the inert gas 6 relative to the change in volume of the gas phase portion 1a of the tank 1 when the volume of the gas phase portion 1a of the tank 1 is 3 L and the pressure (partial pressure) of the inert gas 6 is 0.1 MPa. The dashed-dotted line indicates an example in which the amount of inert gas 6 or the amount of refrigerant 101 filled in the heat transport device 100 is large, resulting in a high pressure (partial pressure) of the inert gas 6. Specifically, the dashed-dotted line indicates the change in the pressure (partial pressure) of the inert gas 6 relative to the change in volume of the gas phase 1a of the tank 1 when the volume of the gas phase 1a of the tank 1 is 3 L and the pressure (partial pressure) of the inert gas 6 is 0.5 MPa.

[0040] Consider the case where the volume of the gas phase portion 1a of the tank 1 is reduced from 3 L to 1 L. In this case, as shown in FIG. 5 , in the example of the solid line, the pressure (partial pressure) of the inert gas 6 increases from 0.1 MPa to 0.3 MPa, and in the example of the dashed-dotted line, the pressure (partial pressure) of the inert gas 6 increases from 0.5 MPa to 1.5 MPa. Thus, in the example of the dashed-dotted line, the pressure (partial pressure) of the inert gas 6, i.e., the evaporation temperature of the refrigerant 101, increases more significantly with respect to the volume change of the gas phase portion 1a of the tank 1. This means that the rate of increase in the evaporation temperature of the refrigerant 101 with respect to the volume change of the gas phase portion 1a of the tank 1 is greater in the example of the dashed-dotted line. Therefore, when the rate of increase in the evaporation temperature of the refrigerant 101 relative to the volume change of the gas phase 1a of the tank 1 is increased (when the rate of increase in the evaporation temperature of the refrigerant 101 is important), the operator increases the amount of inert gas 6 or the amount of refrigerant 101 filled into the heat transport device 100 (increases the pressure (partial pressure) of the inert gas 6) compared to when the rate of decrease in the evaporation temperature of the refrigerant 101 relative to the volume change of the gas phase 1a of the tank 1, as described below.

[0041] Next, consider the case where the pressure (partial pressure) of the inert gas 6 is reduced from 3 MPa to 1 MPa. In this case, as shown in FIG. 6 , in the example of the solid line, the volume of the gas phase 1a of the tank 1 increases from 0.1 L to 0.3 L, and in the example of the dashed-dotted line, the volume of the gas phase 1a of the tank 1 increases from 0.5 L to 1.5 L. Thus, in the example of the solid line, the pressure (partial pressure) of the inert gas 6, i.e., the evaporation temperature of the refrigerant 101, decreases more significantly with respect to the change in volume of the gas phase 1a of the tank 1. This means that the rate of decrease in the evaporation temperature of the refrigerant 101 with respect to the change in volume of the gas phase 1a of the tank 1 is greater in the example of the solid line. Therefore, when the rate of decrease in the evaporation temperature of the refrigerant 101 relative to the volume change of the gas phase portion 1a of the tank 1 is increased (when the rate of decrease in the evaporation temperature of the refrigerant 101 is important), the operator reduces the amount of inert gas 6 or the amount of refrigerant 101 filled into the heat transport device 100 (reducing the pressure (partial pressure) of the inert gas 6) compared to when the rate of increase in the evaporation temperature of the refrigerant 101 relative to the volume change of the gas phase portion 1a of the tank 1 is increased.

[0042] The volume of the gas phase portion 1a of the tank 1 and the pressure (partial pressure) of the inert gas 6 shown in FIGS. 5 and 6 are merely examples, and are not limited to these.

[0043] In step 902, the operator determines the amount of inert gas 6 or the amount of refrigerant 101 to be filled into the heat transport device 100 in order to achieve a desired rate of change in the evaporation temperature of the refrigerant 101. Specifically, the pressure (partial pressure) of the inert gas 6 is determined in order to achieve the desired rate of change in the evaporation temperature of the refrigerant 101, and the amount of inert gas 6 or the amount of refrigerant 101 to be filled into the heat transport device 100 is determined based on the determined pressure (partial pressure) of the inert gas 6. More specifically, the amount of inert gas 6 or the amount of refrigerant 101 to be filled into the heat transport device 100 is determined to be the amount of inert gas 6 or the amount of refrigerant 101 that achieves the determined pressure (partial pressure) of the inert gas 6. At this time, the pressure (partial pressure) of the inert gas 6 in the heat transport device 100 in the contracted state (most contracted state) of the volume change section 7 is determined. That is, the amount of inert gas 6 or the amount of refrigerant 101 to be filled into the heat transport device 100 in the contracted state (most contracted state) of the volume change section 7 is determined (adjusted).

[0044] For example, assume that the pressure (partial pressure) of the inert gas 6 in the heat transport device 100 with the volume change section 7 contracted is set to 0.5 MPa, with emphasis placed on the rate of increase in the evaporation temperature of the refrigerant 101. In this case, the amount of the inert gas 6 or the amount of the refrigerant 101 to be filled into the heat transport device 100 is determined to be the amount that will make the pressure (partial pressure) of the inert gas 6 in the heat transport device 100 with the volume change section 7 contracted 0.5 MPa.

[0045] Furthermore, for example, it is assumed that the pressure (partial pressure) of the inert gas 6 in the heat transport device 100 with the volume change section 7 contracted is set to 0.1 MPa, with emphasis placed on the rate of decrease in the evaporation temperature of the refrigerant 101. In this case, the amount of the inert gas 6 or the amount of the refrigerant 101 to be filled into the heat transport device 100 is determined to be the amount that will make the pressure (partial pressure) of the inert gas 6 in the heat transport device 100 with the volume change section 7 contracted 0.1 MPa.

[0046] 7, when there is no heat input from the preheater 3a and the heat exchanger 3, the refrigerant 101 exists in a liquid state. On the other hand, when there is heat input from the preheater 3a and the heat exchanger 3, a portion of the refrigerant 101 is in a gas-liquid two-phase state. In this case, the generation of gaseous refrigerant 101 increases the amount of liquid refrigerant 101 in the tank 1, and the volume of the gas phase portion 1a of the tank 1 decreases. The decrease in the volume of the gas phase portion 1a of the tank 1 means a decrease in the volume in which the inert gas 6 exists. Therefore, when there is heat input, the pressure (partial pressure) of the inert gas 6 increases compared to when there is no heat input.

[0047] The increase in the pressure (partial pressure) of the inert gas 6 due to heat input can be estimated based on the volume of the gas-liquid two-phase portion with heat input (the amount of liquid refrigerant 101 returning to the tank 1), the volume of the tank 1, and the amount of liquid refrigerant 101 in the tank 1 without heat input. Assuming that all of the inert gas 6 is present in the tank 1, the amount of the inert gas 6 or the refrigerant 101 to be filled into the heat transport device 100 is determined based on the volume of the gas phase portion 1a of the tank 1 without heat input so as to achieve a predetermined pressure (a pressure that results in a desired pressure when the increase in the pressure (partial pressure) of the inert gas 6 is added). Note that in practice, errors may occur due to factors such as the inert gas 6 dissolving in the refrigerant 101, and adjustments may be required to account for this.

[0048] <Step of Filling with Inert Gas> As shown in FIG. 4 , in step 903, the inert gas 6 is filled into the heat transport device 100. If the amount of inert gas 6 is adjusted in step 902, the adjusted amount of inert gas 6 is filled into the heat transport device 100. First, an operator operates the vacuum pump 113 and the manifold 114 to evacuate the heat transport device 100. Then, the inert gas 6 is filled into the evacuated heat transport device 100. Specifically, an operator operates the flow control valve 116 and the manifold 114 to fill the heat transport device 100 with the inert gas 6 from the inert gas source 112. For example, based on the output of a pressure sensor (not shown) provided in the heat transport device 100, the inert gas 6 is filled into the heat transport device 100 until a predetermined pressure corresponding to the desired amount of inert gas 6 is reached. Furthermore, the inert gas 6 is filled into the heat transport device 100 before the refrigerant 101 is filled into the heat transport device 100.

[0049] <Refrigerant Charging Step> In step 904, the heat transport device 100, which was charged with the inert gas 6 in step 903, is charged with the refrigerant 101. If the amount of refrigerant 101 was adjusted in step 902, the adjusted amount of refrigerant 101 is charged into the heat transport device 100. Specifically, an operator operates the flow control valve 115 and the manifold 114 to charge the refrigerant 101 from the refrigerant source 111 into the heat transport device 100 until the refrigerant reaches at least a predetermined amount required for operation of the heat transport device 100. The amount of refrigerant 101 that can be circulated without heat input from the preheater 3a and the heat exchanger 3 is the minimum amount of refrigerant 101 required for operation of the heat transport device 100. Specifically, the minimum amount of refrigerant 101 is the volume of the portion through which the refrigerant 101 circulates (the volume of the pump 2, the heat exchanger 3, the condenser 4, and the pipes 5a to 5d), excluding the volume of the tank 1. Therefore, the heat transport device 100 is filled with the refrigerant 101 in an amount equal to or greater than the volume of the portion where the refrigerant 101 circulates, excluding the volume of the tank 1 .

[0050] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0051] In this embodiment, as described above, a step is provided in which the rate of change of the evaporation temperature of the refrigerant 101 relative to the volume change of the gas phase portion 1a of the tank 1 is adjusted by adjusting the amount of the inert gas 6 or the amount of the refrigerant 101 filled into the heat transport device 100. This allows the rate of change of the evaporation temperature of the refrigerant 101 to be adjusted to a desired rate. As a result, for example, when the heat transport device 100 is used in an application where a rapid increase in the evaporation temperature of the refrigerant 101 is important, the rate of increase in the evaporation temperature of the refrigerant 101 can be increased to quickly increase the evaporation temperature of the refrigerant 101. Also, for example, when the heat transport device 100 is used in an application where a rapid decrease in the evaporation temperature of the refrigerant 101 is important, the rate of decrease in the evaporation temperature of the refrigerant 101 can be increased to quickly decrease the evaporation temperature of the refrigerant 101. This allows effective temperature control when a high priority is placed on the rate of change of the evaporation temperature of the refrigerant 101.

[0052] Furthermore, in the present embodiment, the following additional effects can be obtained by configuring as follows.

[0053] That is, in this embodiment, as described above, the step of adjusting the rate of change of the evaporation temperature of the refrigerant 101 includes a step of increasing the amount of inert gas 6 or the amount of refrigerant 101 filled into the heat transport device 100 when the rate of increase in the evaporation temperature of the refrigerant 101 relative to the volume change of the gas phase 1a of the tank 1 is to be increased, and a step of decreasing the amount of inert gas 6 or the amount of refrigerant 101 filled into the heat transport device 100 when the rate of decrease in the evaporation temperature of the refrigerant 101 relative to the volume change of the gas phase 1a of the tank 1 is to be increased. By utilizing this fact that the rate of increase in the evaporation temperature of the refrigerant 101 increases as the amount of inert gas 6 or the amount of refrigerant 101 filled into the heat transport device 100 increases, effective temperature control can be performed when the heat transport device 100 is used in an application where a rapid increase in the evaporation temperature of the refrigerant 101 is important. Furthermore, by utilizing the fact that the rate of drop in the evaporation temperature of the refrigerant 101 increases as the amount of inert gas 6 or the amount of refrigerant 101 filled in the heat transport device 100 decreases, effective temperature control can be performed when the heat transport device 100 is used in an application where rapid lowering of the evaporation temperature of the refrigerant 101 is important.

[0054] Furthermore, in this embodiment, as described above, the heat transport device 100 includes a volume change unit 7 that is provided in the gas phase 1a of the tank 1 and expands and contracts to change the volume of the gas phase 1a of the tank 1, and the step of adjusting the rate of change of the evaporation temperature of the refrigerant 101 includes a step of adjusting the amount of the inert gas 6 or the refrigerant 101 filled into the heat transport device 100 with the volume change unit 7 contracted. This allows the inert gas 6 or the refrigerant 101 to be filled into the heat transport device 100 with the volume change unit 7 contracted, thereby reducing the load on the volume change unit 7, unlike when the inert gas 6 or the refrigerant 101 is filled into the heat transport device 100 with the volume change unit 7 expanded.

[0055] Furthermore, in this embodiment, as described above, the adjustment method for the heat transport device 100 includes a step of filling the heat transport device 100 in a vacuumed state with the inert gas 6. This allows the heat transport device 100 in a vacuumed state to be filled with the inert gas 6, so that the amount of the filled inert gas 6 can be accurately determined. As a result, the inert gas 6 can be accurately filled.

[0056] Furthermore, in this embodiment, as described above, the method for adjusting the heat transport device 100 includes a step of filling the heat transport device 100 with the inert gas 6 before filling the heat transport device 100 with the refrigerant 101. This prevents the inert gas 6 from dissolving in the refrigerant 101, which is a problem that occurs when the inert gas 6 is filled into the heat transport device 100 after the refrigerant 101 has been filled. As a result, the inert gas 6 can be filled accurately.

[0057] [Modifications] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the description of the above-mentioned embodiments, and further includes all modifications (modifications) within the meaning and scope of the claims.

[0058] For example, in the above embodiment, the refrigerant is carbon dioxide, but the present invention is not limited to this. In the present invention, the refrigerant may be a fluorocarbon-based refrigerant or a natural refrigerant other than carbon dioxide, such as ammonia.

[0059] In addition, although the inert gas is nitrogen in the above embodiment, the present invention is not limited to this example, and the inert gas may be argon.

[0060] In addition, in the above embodiment, an example was shown in which the volume-changing gas was nitrogen, but the present invention is not limited to this. In the present invention, the volume-changing gas may be a gas other than nitrogen.

[0061] In the above embodiment, the volume changeable portion is a metal bellows, but the present invention is not limited to this. In the present invention, the volume changeable portion may be a non-metallic bellows. Furthermore, the volume changeable portion may be a rubber balloon that can expand and contract with a volume change gas, or a cylinder structure in which a piston moves within the cylinder with a volume change gas.

[0062] In the above embodiment, the heat transport device is provided with a preheater, but the present invention is not limited to this. In the present invention, the heat transport device does not necessarily have to be provided with a preheater. In this case, the heat transport device functions only as a cooling device.

[0063] In the above embodiment, the amount of inert gas filled into the heat transport device when the volume change section is in the contracted state (maximum contracted state) is adjusted, but the present invention is not limited to this. In the present invention, the amount of inert gas filled into the heat transport device when the volume change section is in the expanded state (maximum expanded state) may also be adjusted.

[0064] In the above embodiment, the steps of filling the heat transport device with the inert gas and the refrigerant are performed by an operator. However, the present invention is not limited to this. For example, in a modified example shown in FIG. 8 , the steps of filling the heat transport device 100 with the inert gas 6 and the refrigerant 101 are performed by a control device 300. The control device 300 is configured to control the vacuum pump 113, the manifold 114, the flow rate control valve 115, and the flow rate control valve 116. The control device 300 controls the vacuum pump 113 and the manifold 114 to evacuate the heat transport device 100. The control device 300 also controls the flow rate control valve 116 and the manifold 114 to fill the heat transport device 100 with the inert gas 6. The control device 300 also controls the flow rate control valve 115 and the manifold 114 to fill the heat transport device 100 with the refrigerant 101.

[0065] Aspects It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0066] (Item 1) A method for adjusting a heat transport device, comprising: a step of preparing a heat transport device that adjusts the evaporation temperature of a refrigerant by changing the volume of a gas phase of the tank to adjust the pressure of an inert gas sealed in the gas phase of the tank; and a step of adjusting the rate of change of the evaporation temperature of the refrigerant relative to the change in volume of the gas phase of the tank by adjusting the amount of the inert gas or the amount of the refrigerant filled in the heat transport device.

[0067] (Item 2) The method for adjusting a heat transport device according to item 1, wherein the step of adjusting the rate of change of the evaporation temperature of the refrigerant includes the steps of increasing the amount of the inert gas or the amount of the refrigerant filled into the heat transport device when a rate of increase in the evaporation temperature of the refrigerant relative to a volume change in the gas phase of the tank is to be increased, and decreasing the amount of the inert gas or the amount of the refrigerant filled into the heat transport device when a rate of decrease in the evaporation temperature of the refrigerant relative to a volume change in the gas phase of the tank is to be increased.

[0068] (Item 3) The method for adjusting a heat transport device according to Item 1 or 2, wherein the heat transport device includes a volume change unit provided in a gas phase portion of the tank and expanding and contracting to change the volume of the gas phase portion of the tank, and the step of adjusting the rate of change of the evaporation temperature of the refrigerant includes a step of adjusting the amount of the inert gas or the amount of the refrigerant filled in the heat transport device in a state where the volume change unit is contracted.

[0069] (Item 4) The method for adjusting a heat transport device according to any one of Items 1 to 3, further comprising filling the heat transport device in a vacuum state with the inert gas.

[0070] (Item 5) The method for adjusting a heat transport device according to any one of Items 1 to 4, further comprising the step of filling the heat transport device with the inert gas before filling the heat transport device with the refrigerant.

[0071] REFERENCE SIGNS LIST 1 Tank 1a Gas phase portion 6 Inert gas 7 Volume change portion 100 Cooling device 101 Refrigerant

Claims

1. A method for adjusting a heat transport device, comprising the steps of: preparing a heat transport device that adjusts the evaporation temperature of a refrigerant by changing the volume of the gas phase of the tank to adjust the pressure of an inert gas sealed in the gas phase of the tank; and adjusting the rate of change of the evaporation temperature of the refrigerant relative to the change in volume of the gas phase of the tank by adjusting the amount of the inert gas or the amount of the refrigerant filled into the heat transport device.

2. A method for adjusting a heat transport device as described in claim 1, wherein the step of adjusting the rate of change of the evaporation temperature of the refrigerant includes the steps of increasing the amount of the inert gas or the amount of the refrigerant filled into the heat transport device when the rate of increase in the evaporation temperature of the refrigerant relative to the volume change of the gas phase of the tank is to be increased, and decreasing the amount of the inert gas or the amount of the refrigerant filled into the heat transport device when the rate of decrease in the evaporation temperature of the refrigerant relative to the volume change of the gas phase of the tank is to be increased.

3. A method for adjusting a heat transport device as described in claim 1, wherein the heat transport device is provided with a volume change section that is provided in the gas phase section of the tank and changes the volume of the gas phase section of the tank by expanding and contracting, and the step of adjusting the rate of change of the evaporation temperature of the refrigerant includes a step of adjusting the amount of the inert gas or the amount of the refrigerant filled into the heat transport device in a state in which the volume change section is contracted.

4. The method for adjusting a heat transport device according to claim 1, further comprising the step of filling the heat transport device in a vacuum state with the inert gas.

5. The method for adjusting a heat transport device according to claim 1, further comprising the step of filling the heat transport device with the inert gas before filling the heat transport device with the refrigerant.

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