Refrigerant circulation device

Abstract

A refrigerant circulation device according to one embodiment of the present disclosure is provided with a primary flow path, a secondary flow path, a valve, and a control unit. The primary flow path allows a primary refrigerant to flow therethrough. A secondary refrigerant flows through the secondary flow path. The valve is provided in the primary flow path or the secondary flow path, and the opening degree of the valve can be adjusted. The control unit controls the operation of the valve. The control unit causes the valve to perform a predetermined operation when a period during which the valve is not operated exceeds a threshold value.

Description

Technical Field

[0001] The present disclosure relates to a refrigerant cycle device. Background Art

[0002] Conventionally, a cooling control device is known that transfers heat received from a heat source such as a CPU (Central Processing Unit) to a refrigerant circulating inside to cool the heat source (see Patent Document 1).

[0003] The cooling control device described in Patent Document 1 has: a flow path for primary cooling water; a flow path for secondary cooling water that is a refrigerant for cooling the heat source; and a heat exchanger that exchanges heat between the primary cooling water and the secondary cooling water.

[0004] In addition, Patent Document 1 discloses a technique for controlling the temperature of the secondary cooling water to a set temperature by adjusting the opening degree of a valve that changes the flow rate of the primary cooling water to the heat exchanger. Prior Art Documents Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2021-124965 Summary of the Invention

[0006] However, in the cooling control device described in Patent Document 1, when the valve provided in the flow path does not operate for a certain period, deposits formed by the accumulation of ionized metal or impurities adhere to the valve, and the valve may no longer operate normally.

[0007] Therefore, it is desired to implement a refrigerant cycle device that overcomes the above problems and to which deposits are less likely to adhere to the valve provided in the flow path.

[0008] The present disclosure provides a refrigerant cycle device to which deposits are less likely to adhere to the valve.

[0009] A refrigerant cycle device according to one aspect of the present disclosure includes a primary flow path, a secondary flow path, a valve, and a control unit. The primary flow path allows a primary refrigerant to flow. The secondary flow path allows a secondary refrigerant to flow. The valve is provided in the primary flow path or the secondary flow path and can adjust the opening degree. The control unit controls the operation of the valve. When the period during which the valve does not operate exceeds a threshold value, the control unit causes the valve to perform a predetermined operation.

[0010] In the refrigerant cycle device of the present disclosure, deposits are less likely to adhere to the valve. Brief Description of the Drawings

[0011] Figure 1 It is a diagram showing a schematic configuration of a CDU according to the first embodiment. Figure 2It is a flowchart showing the steps of the operation process of the first valve executed by the CDU of the first embodiment. Figure 3 It is a flowchart showing the steps of the operation process of the second valve executed by the CDU of the first embodiment. Figure 4 It is a diagram showing the schematic structure of the CDU of the second embodiment. Detailed Embodiment

[0012] Hereinafter, with reference to the drawings, a mode (hereinafter referred to as "embodiment") for implementing the refrigerant cycle device of the present disclosure will be described in detail. In addition, the present disclosure is not limited by this embodiment. In addition, in each embodiment, the processing contents can be appropriately combined within a non-contradictory range. In addition, in the following embodiments, the same reference numerals are given to the same parts, and repeated explanations are omitted.

[0013] In addition, in each of the drawings referred to below, for the convenience of explanation, an orthogonal coordinate system in which the X-axis direction, the Y-axis direction, and the Z-axis direction that are orthogonal to each other are shown, and the positive direction of the Z-axis is set as the vertically upward direction may be shown.

[0014] (First Embodiment) <Structure of CDU> First, with reference to Figure 1 the schematic structure of the CDU 100 of the first embodiment will be described. Figure 1 It is a diagram showing the schematic structure of the CDU 100 of the first embodiment. In addition, "CDU" is an abbreviation for "Coolant Distribution Unit". The CDU 100 is an example of a refrigerant cycle device.

[0015] The CDU 100 controls the flow rate, temperature, water quality, or water distribution destination of the refrigerant supplied from the equipment side. The CDU 100 sucks the primary refrigerant into the interior of the CDU 100 and pumps the primary refrigerant to the outside of the CDU 100. In addition, the CDU 100 sucks the secondary refrigerant into the interior of the CDU 100 and pumps the secondary refrigerant to the outside of the CDU 100. In addition, since a pump on the primary refrigerant side is not provided inside the CDU 100, the suction and pumping of the primary refrigerant in the CDU 100 are performed by an external pump.

[0016] The CDU100 conducts heat exchange between a primary refrigerant and a secondary refrigerant. For example, refrigerant liquids such as antifreeze and pure water can be used as the primary refrigerant and the secondary refrigerant. As the antifreeze that can be used as a refrigerant, there are ethylene glycol aqueous solutions and propylene glycol aqueous solutions, etc. In addition, the types of the primary refrigerant and the secondary refrigerant can be the same as each other or different. Furthermore, at least one of the primary refrigerant and the secondary refrigerant can also be a gaseous refrigerant.

[0017] As Figure 1 shown, the CDU100 includes a primary flow path 10, a secondary flow path 20, a tank 30, and a heat exchanger 40, which are housed in a housing 100a.

[0018] The primary flow path 10 allows the primary refrigerant to flow through. The primary flow path 10 is a flow path that connects a primary flow inlet 10a provided in the housing 100a and a primary flow outlet 10b. The primary flow inlet 10a and the primary flow outlet 10b are opened on the side surface of the housing 100a on the positive X-axis direction side. The side surface of the housing 100a on the positive X-axis direction side is, for example, the back surface of the housing 100a.

[0019] The primary flow path 10 includes a main flow path 11 and a bypass flow path 12. That is, the primary refrigerant flowing in from the primary flow inlet 10a passes through the main flow path 11, and a part of it passes through the bypass flow path 12 and flows out from the primary flow outlet 10b.

[0020] The main flow path 11 connects the primary flow inlet 10a and the primary flow outlet 10b via the heat exchanger 40. In the main flow path 11, a temperature sensor 111, a pressure sensor 112, a first valve 113 (abbreviated as "valve 113"), the heat exchanger 40, a temperature sensor 114, and a flow sensor 115 are provided from the upstream side.

[0021] The temperature sensor 111 measures the liquid temperature of the primary refrigerant at the upstream side of the primary flow path 10, specifically, at the upstream side of the heat exchanger 40 in the primary flow path 10. The pressure sensor 112 is provided at the downstream side of the temperature sensor 111 in the main flow path 11 and measures the pressure of the primary refrigerant in the primary flow path 10.

[0022] The first valve 113 is provided at the upstream side of the heat exchanger 40 in the main flow path 11. Specifically, the first valve 113 is connected to the main flow path 11 at a position that is downstream of the bifurcation position of the bypass flow path 12 and upstream of the heat exchanger 40 in the main flow path 11. It controls the flow rate of the primary refrigerant in the main flow path 11. The first valve 113 is, for example, an electromagnetic two-way valve. The opening degree of the first valve 113 can be adjusted by a control unit 50 described later.

[0023] The heat exchanger 40 is provided downstream of the first valve 113 in the main flow path 11. The heat exchanger 40 will be described later.

[0024] The bypass flow path 12 branches off from the main flow path 11 at a position upstream of the heat exchanger 40 and downstream of the pressure sensor 112.

[0025] The bypass flow path 12 is provided with a second valve 121 (abbreviated as "valve 121"). The second valve 121 is connected to the bypass flow path 12 and controls the flow rate of the primary refrigerant in the bypass flow path 12. The second valve 121 is, for example, an electromagnetic two-way valve. The opening degree of the second valve 121 can be adjusted by a control unit 50 described later.

[0026] By controlling the opening degrees of the first valve 113 in the main flow path 11 and the second valve 121 in the bypass flow path 12, the inflow amount of the primary refrigerant into the heat exchanger 40 can be adjusted. That is, the heat exchange performance between the primary refrigerant and the secondary refrigerant in the heat exchanger 40 can be adjusted. In addition, by closing the first valve 113 and the second valve 121, the flow of the primary refrigerant can be blocked. Therefore, in the case of a leakage of the primary refrigerant, by closing the valve disposed in the flow path connected to the occurrence site, the flow of the primary refrigerant can be stopped, and the spread of the leakage of the primary refrigerant can be suppressed.

[0027] The bypass flow path 12 joins the main flow path 11 at a position downstream of the heat exchanger 40.

[0028] The temperature sensor 114 is provided at the confluence point of the main flow path 11 and the bypass flow path 12. The temperature sensor 114 measures the liquid temperature of the primary refrigerant on the downstream side of the primary flow path 10, specifically, on the downstream side of the heat exchanger 40 in the primary flow path 10.

[0029] The flow rate sensor 115 is provided downstream of the temperature sensor 114 in the main flow path 11 and measures the flow rate of the primary refrigerant flowing in the primary flow path 10. Since the flow rate sensor 115 is provided downstream of the confluence point of the main flow path 11 and the bypass flow path 12, the flow rate of the entire primary flow path 10 can be measured.

[0030] The secondary flow path 20 allows the secondary refrigerant to flow therethrough. The secondary flow path 20 is a flow path connecting the secondary flow inlet 20a and the secondary flow outlet 20b provided in the housing 100a. The secondary flow inlet 20a and the secondary flow outlet 20b are opened on the side surface of the housing 100a on the positive X-axis direction side.

[0031] The secondary flow path 20 includes a main flow path 21, a supply flow path 22, a first flow path 23, and a second flow path 24. That is, the secondary refrigerant flowing in from the secondary flow inlet 20a passes through the main flow path 21, and passes through either the first flow path 23 or the second flow path 24, and flows out from the secondary flow outlet 20b.

[0032] The main flow path 21 is provided with a temperature sensor 211, a heat exchanger 40, a pressure sensor 214, a temperature sensor 215, and a flow rate sensor 216 from the upstream side.

[0033] The temperature sensor 211 measures the liquid temperature of the secondary refrigerant on the upstream side of the secondary flow path 20, specifically, on the upstream side of the heat exchanger 40 in the secondary flow path 20. The heat exchanger 40 is provided on the downstream side of the temperature sensor 211 in the main flow path 21. The heat exchanger 40 will be described later.

[0034] The supply flow path 22 merges with the main flow path 21 at a position on the downstream side of the heat exchanger 40 in the main flow path 21 and on the upstream side of the bifurcation position of the first flow path 23 and the second flow path 24. The supply flow path 22 is connected to the tank 30. The tank 30 will be described later.

[0035] The main flow path 21 bifurcates into a first flow path 23 and a second flow path 24 at a position on the downstream side of the bifurcation position with the supply flow path 22.

[0036] In the first flow path 23, a pump 231 and a check valve 232 are provided from the upstream side.

[0037] The pump 231 pumps the secondary refrigerant to the downstream side of the first flow path 23. The check valve 232 is provided on the downstream side of the pump 231 in the first flow path 23 to prevent the reverse flow of the secondary refrigerant in the secondary flow path 20.

[0038] In the second flow path 24, a pump 241 and a check valve 242 are provided from the upstream side.

[0039] The pump 241 pumps the secondary refrigerant to the downstream side of the second flow path 24. The check valve 242 is provided on the downstream side of the pump 241 in the second flow path 24 to prevent the reverse flow of the secondary refrigerant in the secondary flow path 20.

[0040] The first flow path 23 and the second flow path 24 merge at their downstream ends, that is, at a position on the downstream side of the check valve 232 and on the downstream side of the check valve 242, and are connected to the main flow path 21.

[0041] The pressure sensor 214 is provided at the confluence point of the first flow path 23 and the second flow path 24 to measure the pressure of the secondary refrigerant in the secondary flow path 20. The pressure sensor 214 measures the pressure of the state where the secondary refrigerant pumped by the pump 231 and the pump 241 merges.

[0042] The temperature sensor 215 measures the liquid temperature of the secondary refrigerant at the downstream side of the secondary flow path 20, specifically, at the downstream side of the heat exchanger 40 in the secondary flow path 20. The flow rate sensor 216 is provided at the downstream side of the temperature sensor 215 in the main flow path 21 and measures the flow rate of the secondary refrigerant flowing in the main flow path 21.

[0043] The tank 30 stores the refrigerant used as the secondary refrigerant. The tank 30 is connected to the supply flow path 22 of the secondary flow path 20. The tank 30 can supply the refrigerant to the secondary flow path 20. When the secondary refrigerant circulating in the secondary flow path 20 decreases, the refrigerant in the tank 30 is replenished to the secondary flow path 20. Thereby, the flow rate of the secondary refrigerant circulating in the secondary flow path 20 can be kept constant. The tank 30 is provided with a liquid level sensor (not shown), an observation window through which the liquid level of the tank 30 can be visually confirmed, a vent valve for releasing the accumulated gas, and a water injection hole for injecting water when the secondary refrigerant decreases.

[0044] The heat exchanger 40 is connected to the primary flow path 10 and the secondary flow path 20. The primary refrigerant and the secondary refrigerant flow into the inside of the heat exchanger 40 and flow out from the inside of the heat exchanger 40. The heat exchanger 40 performs heat exchange between the primary refrigerant and the secondary refrigerant inside thereof. The heat exchange method of the heat exchanger 40 is, for example, a plate type.

[0045] The CDU 100 further includes a control unit 50. The control unit 50 processes commands that can be executed by a computer for causing the CDU 100 to perform various processes described in the present disclosure. The control unit 50 can be configured to control each element of the CDU 100 in a manner of executing various processes described herein. For example, the control unit 50 controls the operation of the valve 113 or the valve 121. In the first embodiment, the CDU 100 may also include a part or all of the control unit 50.

[0046] The control unit 50 may include a processing unit, a storage unit, and a communication interface. The control unit 50 is implemented by a computer, for example. The processing unit may be configured to read a program from the storage unit and perform various control actions by executing the read program. The above program may be pre-stored in the storage unit, and when necessary, it may also be obtained through a medium. The obtained program is stored in the storage unit and read and executed by the processing unit. The medium may be various storage media readable by a computer, or a communication line connected to the communication interface. The processing unit may be a CPU (Central Processing Unit). The storage unit may include an RMA (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface may communicate with the CDU 100 via a communication line such as a LAN (Local Area Network).

[0047] In addition, Figure 1 An example of the structure of the CDU 100 is shown, and it may also include Figure 1 components other than the components shown. For example, the CDU 100 may also include a touch screen. The touch screen is provided on the side of the housing 100a in the negative X-axis direction and displays the operating status of the system and the measured values of each sensor. In addition, the CDU 100 may also include a power supply unit. The power supply unit supplies power to the pumps 231, 241, valves 113, 121, etc. described later. When power is supplied from the outside, the CDU 100 may not be provided with a power supply unit.

[0048] In addition, it may be that, in addition to Figure 1 the sensors shown, the CDU 100 also includes other sensors. Examples of other sensors include a flow rate sensor for measuring the flow rate of the primary refrigerant in the primary flow path 10 or the secondary refrigerant in the secondary flow path 20, a water quality sensor for measuring the conductivity, turbidity, ion index, pH, etc. of the primary refrigerant or the secondary refrigerant, a humidity sensor for measuring the humidity inside the CDU 100, a leakage sensor for detecting liquid leakage inside the CDU 100, etc.

[0049] Among the sensors, some are disposed within the primary flow path 10 or the secondary flow path 20, and some are disposed outside the primary flow path 10 or the secondary flow path 20. For example, as sensors disposed within the primary flow path 10 or the secondary flow path 20, pressure sensors 112, 214 and flow rate sensors 115, 216 can be cited. In addition, as sensors disposed outside the primary flow path 10 or the secondary flow path 20, a humidity sensor and a leakage sensor can be cited. In addition, the "inside the primary flow path 10" described in the present disclosure does not only include the part where the primary refrigerant circulates, but also includes the space fluidly connected to the primary flow path 10.

[0050] The above-mentioned sensors are connected to the control unit 50 and can send the measurement results to the control unit 50. In addition, the above-mentioned sensors are connected to the control unit 50 in a hot-pluggable manner, and can be plugged and unplugged even when the CDU 100 is in operation. Therefore, when a sensor malfunctions, the sensor can be repaired without stopping the CDU 100, and the influence on the server can be suppressed. By arranging a plurality of sensors of the same type close to each other, even if one of the sensors is unplugged, measurement can continue in a relatively close range.

[0051] In the CDU 100 configured as described above, when the valve 113 or the valve 121 does not operate for a certain period of time, deposits formed by the accumulation of ionized metal or impurities are fixed to the valve 113 or the valve 121, and the valve 113 or the valve 121 may no longer operate normally. In addition, it is possible that even if the valves 113 and 121 malfunction, it cannot be detected. In addition, when the valve 113 or the valve 121 does not operate for a long time, it may be fixed and cause a failure.

[0052] Therefore, when the valve 113 or the valve 121 does not operate for a certain time, the CDU 100 of the first embodiment causes the valve 113 or the valve 121 to perform a predetermined operation. As a result, deposits are less likely to accumulate on the valve 113 or the valve 121. In addition, even if the valve 113 or the valve 121 malfunctions, it can be detected as early as possible. Specifically, if the valve 113 or the valve 121 no longer operates due to a failure, and the failure is detected after the temperature of the secondary refrigerant goes out of the threshold range, then the temperature of the secondary refrigerant needs to be adjusted. On the other hand, according to the CDU 100 of the first embodiment, the failure can be detected before the above temperature adjustment is required. Hereinafter, with reference to Figure 2 , the specific operation process of the CDU 100 will be described.

[0053] <Specific Operations of the CDU> Figure 2 It is a flowchart showing the steps of the operation process of the first valve 113 executed by the CDU 100 of the first embodiment.

[0054] First, the control unit 50 determines whether the period during which the first valve 113 is not actuated exceeds a threshold value (step S101). The threshold value is, for example, three days.

[0055] When the control unit 50 determines that the period during which the first valve 113 is not actuated exceeds the threshold value (step S101, YES), it acquires the liquid temperature of the secondary refrigerant from the temperature sensors 211 and 215 in the secondary flow path 20 (step S102). For example, the control unit 50 may use the average value of the measured values respectively acquired from the temperature sensors 211 and 215 as the liquid temperature of the secondary refrigerant.

[0056] Next, the control unit 50 determines whether the liquid temperature of the secondary refrigerant is within a predetermined temperature range (step S103). When the liquid temperature of the secondary refrigerant is within the predetermined temperature range (step S103, YES), the control unit 50 advances the process to step S104. On the other hand, when the liquid temperature of the secondary refrigerant is not within the predetermined temperature range (step S103, NO), the control unit 50 ends the process of this flow.

[0057] Next, the control unit 50 acquires information on the opening degree of the first valve 113 from the first valve 113. In addition, the control unit 50 acquires the measured value from the pressure sensor 214 (step S104).

[0058] Next, the control unit 50 determines whether the measured value of the pressure sensor 214 changes significantly (step S105). For example, when the change in the measured value of the pressure sensor 214 is larger than the change amplitude of the pressure sensor 214 corresponding to the opening degree of the first valve 113 measured in advance, the control unit 50 determines that the measured value of the pressure sensor 214 changes significantly.

[0059] When the measured value of the pressure sensor 214 changes significantly (step S105, YES), the control unit 50 advances the process to step S106. On the other hand, when the measured value of the pressure sensor 214 does not change significantly (step S105, NO), the control unit 50 ends the process of this flow.

[0060] Next, the control unit 50 opens the second valve 121 (step S106). Here, "opening" includes not only the fully open state but also the open state with an opening degree of a certain value or more. That is, the control unit 50 increases the opening degree of the second valve 121 to a certain value or more. In addition, when the second valve 121 is already open, the control unit 50 may also skip this process.

[0061] Next, the control unit 50 causes the first valve 113 to perform a predetermined operation (step S107). For example, the control unit 50 may increase the opening degree of the first valve 113. In addition, the control unit 50 may also decrease the opening degree of the first valve 113. In addition, the control unit 50 may also perform operations of increasing and decreasing the opening degree of the first valve 113. In addition, the control unit 50 may also perform operations of increasing and decreasing the opening degree of the first valve 113 multiple times. Here, ideally, the opening degree of the first valve 113 is the same before and after the predetermined operation. Thereby, it is possible to suppress the change in the flow of the secondary refrigerant before and after the predetermined operation of the first valve 113.

[0062] Here, when the first valve 113 does not perform a predetermined operation, for example, when the opening degree of the first valve 113 does not change or an error is output from the first valve 113, the control unit 50 may use a display unit (not shown) such as a touch screen to notify an error.

[0063] Next, the control unit 50 confirms the operation of the sensor (step S108). Specifically, the control unit 50 confirms the operations of the flow rate sensors 115 and 216 or the pressure sensors 112 and 214. For example, while causing the first valve 113 to perform a predetermined operation, the control unit 50 confirms whether the measured value of the flow rate sensor 115 changes. When the measured value of the flow rate sensor 115 changes, the control unit 50 determines that the flow rate sensor 115 is operating normally. On the other hand, when the measured value of the flow rate sensor 115 does not change, the control unit 50 determines that the flow rate sensor is not operating normally and may use a display unit (not shown) such as a touch screen to notify an error.

[0064] The control unit 50 can similarly confirm the operations of the flow rate sensor 216 or the pressure sensors 112 and 214. In addition, the control unit 50 can similarly confirm the operations of other sensors such as the temperature sensors 111, 114, 211, and 215.

[0065] As described above, when the period during which the valve 113 does not operate exceeds the threshold value, the control unit 50 of the CDU 100 of the first embodiment causes the valve 113 to perform a predetermined operation.

[0066] By causing the valve 113 to operate regularly in this way, deposits are less likely to adhere to the valve 113.

[0067] While one of the first valve 113 and the second valve 121 is performing a predetermined operation, the control unit 50 may also open the other of the first valve 113 and the second valve 121.

[0068] Thereby, it is possible to suppress the increase in the internal pressure in the primary flow path 10 by the operation of the first valve 113 or the second valve 121.

[0069] Here, ideally, before and after a predetermined operation of one of the first valve 113 and the second valve 121, the opening degrees of the other of the first valve 113 and the second valve 121 are the same. Thereby, it is possible to suppress a change in the flow of the secondary refrigerant before and after the predetermined operation of the first valve 113 or the second valve 121.

[0070] When the period during which the valve 113 is not operated exceeds a threshold value and the liquid temperature of the secondary refrigerant obtained from the temperature sensors 211 and 215 is within a predetermined temperature range, the control unit 50 may also cause the valve 113 to perform a predetermined operation. In other words, even when the period during which the valve 113 is not operated exceeds the threshold value, when the liquid temperature of the secondary refrigerant is outside the predetermined range, the valve 113 may not be caused to perform a predetermined operation.

[0071] The case where the liquid temperature of the secondary refrigerant is outside the temperature range is a case where adjustment of the liquid temperature of the secondary refrigerant is required. Therefore, no operation is performed in this case. Thereby, the cooling performance of the CDU 100 can be maintained. In addition, condensation in the primary flow path 10 and the secondary flow path 20 can be suppressed.

[0072] The control unit 50 determines whether to perform a predetermined operation based on the measured value of the pressure sensor 112 and the opening degree of the first valve 113.

[0073] If deposits adhere to the valve 113, the pressure in the primary flow path 10 tends to rise. Therefore, by determining whether the valve 113 should be operated based on the measured value of the pressure sensor 112 in the primary flow path 10, the progression of deposits adhering to the valve 113 can be suppressed.

[0074] In addition, the storage unit of the control unit 50 may include a plurality of thresholds for determining the period during which the valve 113 is not operated. It may be that the control unit 50 selects one threshold from the plurality of thresholds based on the measured value of the pressure sensor 112 and determines whether the period during which the valve 113 is not operated exceeds one threshold. For example, when the measured value of the pressure sensor 112 is large, a smaller threshold may be selected from the plurality of thresholds.

[0075] Thereby, it is possible to perform operation processing in a shorter period than usual when the internal pressure of the primary flow path 10 has an upward tendency, and the progression of deposits adhering to the valve 113 can be suppressed.

[0076] The control unit 50 may also confirm whether the sensor is operating normally based on a change in the measured value of a sensor (as an example, the flow sensors 115 and 216 or the pressure sensors 112 and 214) during a predetermined operation.

[0077] Accordingly, it is possible to confirm whether the sensor is operating normally while suppressing the solidification of deposits in the valve 113.

[0078] In addition, the second valve 121 may be subjected to the same operation processing as that of Figure 2 the flowchart. Figure 3 FIG. is a flowchart showing the steps of the operation processing of the second valve 121 executed by the CDU 100 of the first embodiment. In addition, except for the difference in the object to be operated by the control unit 50, it is the same as the flowchart of Figure 2 Therefore, the detailed description of each step is omitted.

[0079] First, the control unit 50 determines whether the period during which the second valve 121 is not operating has exceeded a threshold value (step S201). When the control unit 50 determines that the period during which the second valve 121 is not operating has exceeded the threshold value (step S201, YES), the process proceeds to step S202.

[0080] Next, in steps S202 and S203, the control unit 50 performs the same processing as steps S102 and S103 of Figure 2 the flowchart.

[0081] Next, the control unit 50 acquires information on the opening degree of the second valve 121 from the second valve 121. In addition, the control unit 50 acquires a measurement value from the pressure sensor 214 (step S204).

[0082] Next, the control unit 50 determines whether the opening degree of the second valve 121 and the measurement value of the pressure sensor 214 are respectively within the threshold ranges (step S205). When the opening degree of the second valve 121 and the measurement value of the pressure sensor 214 are respectively within the threshold ranges (step S205, YES), the control unit 50 advances the process to step S106. On the other hand, when the opening degree of the second valve 121 and the measurement value of the pressure sensor 214 are not respectively within the threshold ranges (step S205, NO), the control unit 50 ends the processing of this flow.

[0083] Next, the control unit 50 opens the first valve 113 (step S206) and causes the second valve to perform a predetermined operation (step S207).

[0084] Next, the control unit 50 confirms the operation of the sensor (step S208).

[0085] In addition, the processing of this flow may also be executed at a time point staggered from the operation processing of the first valve 113 shown in Figure 2 Accordingly, compared with the case where the operation processing of the first valve 113 and the operation processing of the second valve 121 are performed simultaneously, it is less likely to affect the flow of the primary refrigerant, and it is possible to suppress the increase in the internal pressure of the primary flow path 10.

[0086] In addition, an example of the operation processing of the first valve 113 and the second valve 121 provided in the primary flow path 10 is shown here, but the valves to be subjected to the operation processing are not limited thereto. For example, the valve (not shown) provided in the secondary flow path 20 may be subjected to the operation processing. In addition, the arrangement position and the number of arranged valves are not limited to Figure 2 the example of

[0087] In addition, the control unit 50 may also adjust the opening degree of the valve 113 or the valve 121 according to the measurement value of the pressure sensor 214. According to the above structure, the internal pressure rise of the primary flow path 10 can be suppressed.

[0088] In addition, it may be that after the control unit 50 closes the valve 113 or the valve 121, the above-mentioned Figure 2 processing shown in the flowchart is performed. Since the internal pressure of the primary flow path 10 rises due to the closing of the valve 113 and the valve 121, the deposits on the valve 113 or the valve 121 are more easily removed when the operation processing is performed.

[0089] In addition, there may be a plurality of pressure sensors provided in the primary flow path 10. Similarly, there may be a plurality of pressure sensors provided in the secondary flow path 20.

[0090] In addition, in Figure 2 in step S105 shown, the control unit 50 may further use the measurement value of the flow sensor 115 to determine whether the change in the measurement value of the pressure sensor 214 is large.

[0091] As described above, when the period during which the valve 113 does not operate exceeds the threshold value, the control unit 50 of the CDU 100 of the first embodiment causes the valve 113 to perform a predetermined operation. By causing the valve 113 to operate regularly in this way, deposits are less likely to adhere to the valve 113.

[0092] (Second Embodiment) In the first embodiment, an example in which the two two-way valves, the valve 113 and the valve 121, are provided in the primary flow path 10 has been described, but the types of valves are not limited thereto. One three-way valve may be provided in the primary flow path 10 instead of the two two-way valves. Figure 4 is a diagram showing a schematic structure of the CDU 100 of the second embodiment.

[0093] The valve 19 is provided at the bifurcation point of the main flow path 11 and the bypass flow path 12, and controls the flow rate of the primary refrigerant in the main flow path 11 and the bypass flow path 12. The valve 19 is, for example, an electromagnetic three-way valve. The opening degree of the valve 19 can be adjusted by the control unit 50.

[0094] The valve 19 may include a first valve that controls the flow rate of the primary refrigerant in the main flow path 11 and a second valve that controls the flow rate of the primary refrigerant in the bypass flow path 12. The control unit 50 adjusts the inflow amount of the primary refrigerant into the heat exchanger 40 by controlling the opening degrees of the first valve and the second valve. That is, the heat exchange performance between the primary refrigerant and the secondary refrigerant in the heat exchanger 40 is adjustable.

[0095] In this way, by configuring a three-way valve in the primary flow path 10, the number of valves used can be reduced, and the cost can be lowered.

[0096] (Other embodiments) <Operation process of the pump> The CDU 100 of the present disclosure includes a plurality of pumps 231 and 241 (refer to Figure 1 ), so it is possible to operate only one of the plurality of pumps 231 and 241 and make the other pumps standby. When the standby pump does not operate for a certain period, the operation process can be performed in the same manner as the first valve 113 and the second valve 121.

[0097] <Removal of deposits based on the opening and closing of the valve> Deposits accumulate on the components or flow path pipes arranged in the primary flow path 10 or the secondary flow path 20, which may cause malfunction or reduce the area through which the primary refrigerant or the secondary refrigerant can flow. Specifically, when a sensor is arranged in the flow path pipe, the function of the sensor may be restricted due to the accumulation of deposits around the sensor. In addition, when deposits accumulate in a part of the primary flow path 10 or the secondary flow path 20 where the flow path resistance is high (a bent part or a narrow flow path part), it is more likely that the flow path resistance increases and affects the circulation of the primary refrigerant or the secondary refrigerant.

[0098] Therefore, as Figure 1 shown, when the valve 113 or the valve 121 is arranged in the primary flow path 10, by repeatedly opening and closing the valve 113 or the valve 121, turbulent flow can be caused near the valve 113 or the valve 121, and the fixed deposits can be peeled off from the fixed position by the turbulent flow and circulated in the flow path. In addition, by arranging a mesh filter in the primary flow path 10, the deposits can be blocked by the filter, and the re-fixation to other components can be suppressed. The filter can be removed from the primary flow path 10, and can be removed and repaired when the filter is blocked. The opening and closing speed of the valve 113 or the valve 121 for causing the above-mentioned turbulent flow is faster than the opening and closing speed of the valve 113 or the valve 121 for adjusting the refrigerant amount flowing in the primary flow path 10.

[0099] The time point at which the turbulent flow is generated to make the deposits flow can be carried out in matching with the operation process of the valve 113 or valve 121 in the first embodiment. In addition, it can also be carried out at the time point when the influence caused by the deposits is detected according to the measured value of the sensor (such as the flow rate measured by the flow sensors 115, 216, etc.) or the rotation speed of the pumps 231, 241, etc.

[0100] By making the turbulent flow larger or forming an impact flow, it is possible to make large deposits or strongly fixed deposits flow. As methods for making the turbulent flow larger or forming an impact flow, examples include increasing the opening and closing speed of the valve 113 or valve 121, increasing the number of opening and closing operations, and increasing the flow rate of the refrigerant in one cycle of the circulation. In addition, this treatment can also be performed on the valves provided in the secondary flow path 20.

[0101] <Removal of deposits based on the operation of the pump> As Figure 1 shown, when the pump 231 or pump 241 is arranged in the primary flow path 10, it is possible to generate a turbulent flow by adjusting the rotation of the pump 231 or pump 241. A turbulent flow can be caused by repeatedly rotating, stopping, or rotating in the reverse direction the pump 231 or pump 241.

[0102] In addition, the change in the rotation speed of the pump 231 or pump 241 for causing a turbulent flow is larger than the change in the rotation speed of the pump 231 or pump 241 for adjusting the amount of refrigerant flowing in the primary flow path 10 and the secondary flow path 20. Examples for making the turbulent flow larger or forming an impact flow include increasing the rotation speed of the pump 231 or pump 241, sudden stop, or increasing the amount of refrigerant in the cycle.

[0103] <Self-diagnosis function of each component> The components arranged in the CDU 100 and connected to the control unit 50 can notify the control unit 50 in case of an abnormality. In addition, each component can perform self-diagnosis on the period until maintenance is required by recording the operating conditions, maintenance frequency, etc. For example, as components that can perform self-diagnosis, examples include the valves 113, 121 or the pumps 231, 241, but even components not described can be made to have a self-diagnosis function.

[0104] The valve 113 or valve 121 has the following functions: self-diagnosis of the period when maintenance is required based on the action detection during the action process of the valve 113 or valve 121 shown in the first embodiment, the number of opening and closing operations since the previous maintenance, the accumulation of the change amount, and the continuous operation time, etc.

[0105] The pump 231 or the pump 241 has the following functions: self-diagnosis of the period requiring maintenance based on the action detection during the operation process of the above-mentioned pump 231 or pump 241, or the cumulative number of rotations, the change frequency of the rotational speed, the start and stop times, etc. since the previous maintenance. In addition, as an index for the period until maintenance, it is also possible to compare the number of rotations at the same duty ratio stored in the storage unit and use the changing ratio. In addition, it is possible to determine whether the pump 231 or pump 241 is normal by comparing with the operating sound during normal operation or the operating sound during abnormal operation.

[0106] <Flow path for cleaning> Specific parts can be disconnected from the primary flow path 10 and the secondary flow path 20 by providing detachable couplers (quick fluid connectors) in the primary flow path 10 and the secondary flow path 20 within the CDU100 and disconnecting the couplers. For example, by providing couplers upstream of the inlet and downstream of the outlet of the heat exchanger 40, the heat exchanger 40 can be disconnected from the primary flow path 10 and the secondary flow path 20. When dirt (scale) formed by the precipitation of inorganic salts such as silica, calcium, and magnesium dissolved in the refrigerant flowing in the primary flow path 10 or the secondary flow path 20 adheres or solidifies, the heat exchanger 40 is disconnected by cutting the coupler, and an external connection coupler connected to the cleaning flow path is installed. Thus, strong acids, etc. can flow through from the cleaning flow path to clean the dirt.

[0107] The substances used for cleaning are not limited to strong acids, and alkaline liquids or liquids with other properties can also be used. In addition, not limited to liquids, cleaning based on gas impact, using powders or granules can also be performed.

[0108] As a method other than the separation from the flow path based on the coupler, a cleaning flow path can also be set by providing a valve (such as a three-way valve or a combination of two two-way valves, etc.) that can switch the flow path.

[0109] Three-way valves can be provided respectively upstream of the inlet and downstream of the outlet of the heat exchanger 40, and the control unit 50 can operate the three-way valves to separate the circulation flow path and the cleaning flow path.

[0110] For example, when circulating the refrigerant, the control unit 50 opens the valve communicating with the circulation flow path in the three-way valve and closes the valve communicating with the cleaning flow path. On the other hand, when performing cleaning, the control unit 50 opens the valve communicating with the cleaning flow path and closes the valve communicating with the circulation flow path. In addition, when an acidic or alkaline liquid flows through, by neutralizing the inside of the heat exchanger 40 after cleaning, the influence during refrigerant circulation can be suppressed.

[0111] In addition, in the above description, the heat exchanger 40 of the CDU 100 is described, but it may also be a component other than the heat exchanger 40. In addition, even components outside the CDU 100 (for example, a closed water cooling system composed of a radiator, a water block, etc.) may have the same structure.

[0112] In addition, the present technology may also adopt the following structure. (1) A refrigerant circulation device, comprising: A primary flow path through which a primary refrigerant circulates; A secondary flow path through which a secondary refrigerant circulates; A valve provided in the primary flow path or the secondary flow path and capable of adjusting the opening degree; and A control unit that controls the operation of the valve, When the period during which the valve does not operate exceeds a threshold value, the control unit causes the valve to perform a predetermined operation. (2) Based on the refrigerant circulation device described in (1), It further comprises a heat exchanger connected to the primary flow path and the secondary flow path, The primary flow path includes: A main flow path that connects the inlet and outlet of the primary refrigerant via the heat exchanger; and A bypass flow path that branches off from the main flow path at a position upstream of the heat exchanger and merges with the main flow path at a position downstream of the heat exchanger, The valve includes: A first valve that is connected to the main flow path at a position downstream of the branching position of the bypass flow path and upstream of the heat exchanger in the main flow path; and A second valve that is connected to the bypass flow path, During the period when one of the first valve and the second valve is performing the predetermined operation, the control unit opens the other of the first valve and the second valve. (3) Based on the refrigerant circulation device described in (1) or (2), It further comprises a temperature sensor provided in the secondary flow path, When the period during which the valve does not operate exceeds a threshold value and the liquid temperature of the secondary refrigerant obtained from the temperature sensor is within a predetermined temperature range, the control unit causes the valve to perform the predetermined operation. (4) Based on the refrigerant circulation device described in any one of (1) to (3), It also includes a pressure sensor disposed in the primary flow path. The control unit determines whether to perform the predetermined operation based on the measured value of the pressure sensor and the opening degree of the valve. (5) Based on the refrigerant cycle device according to any one of (1) to (4), It also includes a sensor disposed in the primary flow path or the secondary flow path. The control unit confirms whether the sensor is operating normally based on the change in the measured value of the sensor during the predetermined operation.

[0113] It should be considered that the embodiments disclosed herein are illustrative in all aspects and do not constitute limitations. In fact, the above embodiments can be embodied in various ways. In addition, the above embodiments can be omitted, replaced, and changed in various ways without departing from the appended claims and their gist. Symbol Explanation

[0114] 10 Primary flow path 10a Primary flow inlet 10b Primary flow outlet 11 Main flow path 12 Bypass flow path 111, 114, 211, 215 Temperature sensors 115, 216 Flow rate sensors 20 Secondary flow path 20a Secondary flow inlet 20b Secondary flow outlet 30 Tank 40 Heat exchanger 50 Control unit 100 CDU 112, 214 Pressure sensors 113 First valve 121 Second valve 231, 241 Pumps 232, 242 Check valves.

Claims

1. A refrigerant cycle device, characterized in that: have: A primary flow path, wherein the primary flow path is used for the circulation of a primary refrigerant; A secondary flow path, wherein the secondary flow path is used for the circulation of a secondary refrigerant; A valve, the valve being arranged in the primary flow path or the secondary flow path and capable of adjusting the opening degree; as well as a control unit, wherein the control unit controls the operation of the valve, The control unit causes the valve to perform a predetermined operation when the period during which the valve is not operated exceeds a threshold value.

2. The refrigerant cycle device according to claim 1, characterized in that: A heat exchanger is further provided, wherein the heat exchanger is connected to the primary flow path and the secondary flow path, The primary flow path comprises: a main flow path connecting an inlet and an outlet of the primary refrigerant via the heat exchanger; and a bypass flow path that branches off from the main flow path at a position upstream of the heat exchanger and merges with the main flow path at a position downstream of the heat exchanger, The valve comprises: a first valve connected to the main flow path at a position in the main flow path downstream of a branching position of the bypass flow path and upstream of the heat exchanger; and a second valve connected to the bypass flow path, The control unit opens one of the first valve and the second valve while the other of the first valve and the second valve is performing the predetermined operation.

3. The refrigerant cycle device according to claim 1, characterized in that: further comprising a temperature sensor disposed in the secondary flow path, The control unit causes the valve to perform the predetermined operation when the period during which the valve is not operated exceeds a threshold value and the liquid temperature of the secondary refrigerant acquired from the temperature sensor is within a predetermined temperature range.

4. The refrigerant cycle device according to claim 1, characterized in that: further comprising a pressure sensor disposed in the primary flow path, The control unit determines whether to perform the predetermined operation based on the measurement value of the pressure sensor and the opening degree of the valve.

5. The refrigerant cycle device according to claim 1, characterized in that: further comprising a sensor disposed in the primary flow path or the secondary flow path, The control unit confirms whether the sensor is operating normally based on a change in a measurement value of the sensor during the predetermined operation.

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