Refrigeration circulation device

Abstract

To provide a refrigerant circulation device in which deposits hardly adhere to the valve.SOLUTION: A refrigerant circulation device according to an embodiment includes a primary flow passage, a secondary flow passage, a valve, and a control unit. A first refrigerant flows through the primary flow passage. A second refrigerant flows through the secondary flow passage. The valve is provided in the primary flow passage or the secondary flow passage, and an opening thereof is adjustable. The control unit controls the operation of the valve. The control unit makes the valve perform the predetermined operation when a time period in which the valve does not operate exceeds a threshold.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a refrigerant circulation device.

Background Art

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

[0003] The cooling control device described in Patent Document 1 includes a flow path for primary cooling water, a flow path for secondary cooling water as a refrigerant for cooling the heat source, and a heat exchanger that performs heat exchange between the primary cooling water and the secondary cooling water.

[0004] Further, 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

Summary of the Invention

Problems to be Solved by 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 such as ionized metal or impurities may adhere to the valve, and the valve may not operate normally.

[0007] Therefore, it is expected to realize a refrigerant circulation device that overcomes the above problems and in which deposits hardly adhere to the valve provided in the flow path.

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

Means for Solving the Problems

[0009] The refrigerant circulation 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 therethrough. The secondary flow path allows a secondary refrigerant to flow therethrough. The valve is provided in the primary flow path or the secondary flow path and is capable of adjusting its opening degree. The control unit controls the operation of the valve. When the period during which the valve is not operating exceeds a threshold value, the control unit causes the valve to perform a predetermined operation.

Effects of the Invention

[0010] In the refrigerant circulation device of the present disclosure, deposits are less likely to adhere to the valve.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0012] Hereinafter, modes for carrying out the refrigerant circulation device according to the present disclosure (hereinafter referred to as "embodiments") will be described in detail with reference to the drawings. Note that the present disclosure is not limited by this embodiment. Also, the respective embodiments can be appropriately combined within a range that does not cause contradictions in the processing content. In addition, in the following respective embodiments, the same parts are denoted by the same reference numerals, and redundant explanations are omitted.

[0013] In addition, in each of the drawings referred to below, for the sake of easy understanding of the description, there may be a case where an orthogonal coordinate system is shown in which the X-axis direction, the Y-axis direction, and the Z-axis direction orthogonal to each other are defined, and the positive Z-axis direction is the vertically upward direction.

[0014] (First Embodiment) <Configuration of CDU> First, with reference to FIG. 1, the schematic configuration of the CDU 100 according to the first embodiment will be described. FIG. 1 is a diagram showing the schematic configuration of the CDU 100 according to the first embodiment. Note that "CDU" is an abbreviation for "Coolant Distribution Unit". The CDU 100 is an example of a refrigerant circulation device.

[0015] The CDU 100 controls the flow rate, temperature, water quality, or water distribution destination of the refrigerant supplied from the facility side. The CDU 100 sucks the primary refrigerant into the inside 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 inside of the CDU 100 and pumps the secondary refrigerant to the outside of the CDU 100. Note that since no pump on the primary refrigerant side is 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 CDU 100 performs heat exchange between the primary refrigerant and the secondary refrigerant. For example, refrigerant liquids such as antifreeze and pure water can be used as the primary refrigerant and the secondary refrigerant. Examples of the antifreeze that can be used as the refrigerant include an ethylene glycol aqueous solution and a propylene glycol aqueous solution. Note that the types of the primary refrigerant and the secondary refrigerant may be the same as or different from each other. In addition, at least one of the primary refrigerant and the secondary refrigerant may be a gas refrigerant.

[0017] As shown in FIG. 1, the CDU 100 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 connecting the primary inlet 10a and the primary outlet 10b provided in the housing 100a. The primary inlet 10a and the primary outlet 10b open to the side surface of the housing 100a on the positive X-axis side. The side surface of the housing 100a on the positive X-axis 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 medium flowing in from the primary 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 outlet 10b.

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

[0021] The temperature sensor 111 measures the liquid temperature of the primary refrigerant on the upstream side of the primary flow path 10, specifically, on the upstream side of the heat exchanger 40 in the primary flow path 10. The pressure sensor 112 is provided on 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 on 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 downstream of the branch position of the bypass flow path 12 in the main flow path 11 and upstream of the heat exchanger 40. 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 on the downstream side 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] A second valve 121 (also simply referred to as "valve 121") is provided in the bypass flow path 12. 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. Also, by closing the first valve 113 and the second valve 121, the flow of the primary refrigerant can be stopped. Therefore, when a leak of the primary refrigerant occurs, by closing the valve arranged in the flow path connected to the occurrence location, the flow of the primary refrigerant can be stopped and the spread of the leak of the primary refrigerant can be suppressed.

[0027] The bypass flow path 12 merges with 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 through 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 through. The secondary flow path 20 is a flow path that connects a secondary flow inlet 20a and a secondary flow outlet 20b provided in the housing 100a. The secondary flow inlet 20a and the secondary flow outlet 20b open 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 medium flowing in from the secondary flow inlet 20a passes through the main flow path 21 and also passes through the first flow path 23 or the second flow path 24, and then flows out from the secondary flow outlet 20b.

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

[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 11. The heat exchanger 40 will be described later.

[0034] The supply flow path 22 merges with the main flow path 21 at a position downstream of the heat exchanger 40 in the main flow path 21 and upstream of the branch positions 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 branches into a first flow path 23 and a second flow path 24 at a position downstream of the branch position with the supply flow path 22.

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

[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 flowing through 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 branched second flow path 24 to prevent the backflow of the secondary refrigerant flowing through 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 positions downstream of the check valve 232 and downstream 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 in the state where the secondary refrigerants pumped from the pump 231 and the pump 241 merge.

[0042] The temperature sensor 215 measures the liquid temperature of the secondary refrigerant on the downstream side of the secondary flow path 20, specifically, on the downstream side of the heat exchanger 40 in the secondary flow path 20. The flow rate sensor 216 is provided on the downstream side of the temperature sensor 215 in the main flow path 21 to measure the flow rate of the secondary refrigerant flowing through 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), a sight glass through which the liquid level of the tank 30 can be visually confirmed, an air vent valve for discharging the accumulated gas, and a water injection hole through which water can be injected 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 interior of the heat exchanger 40 and flow out from the interior 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 computer-executable instructions for causing the CDU 100 to execute various processes described in the present disclosure. The control unit 50 may be configured to control each element of the CDU 100 so as to execute the 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, part or all of the control unit 50 may be included in the CDU 100.

[0046] The control unit 50 may include a processing unit, a storage unit, and a communication interface. The control unit 50 is realized, for example, by a computer. The processing unit may be configured to read a program from the storage unit and perform various control operations by executing the read program. This program may be stored in the storage unit in advance, or may be acquired via a medium when necessary. The acquired program is stored in the storage unit and read from the storage unit by the processing unit and executed. The medium may be various storage media readable by a computer, or may be a communication line connected to the communication interface. The processing unit may be a CPU (Central Processing Unit). The storage unit may include a RAM (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] Note that FIG. 1 shows an example of the configuration of the CDU 100, and the CDU 100 may further include members other than those shown in FIG. 1. For example, the CDU 100 may be provided with a touch screen. The touch screen is provided on the side surface of the housing 100a on the negative X-axis side, and displays the operating status of the system and the measured values of each sensor. Also, the CDU 100 may be provided with 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 does not necessarily need to be provided with a power supply unit.

[0048] In addition to the sensors shown in FIG. 1, the CDU 100 may further include other sensors. Examples of other sensors include a flow rate sensor that measures the flow rate of the primary refrigerant or secondary refrigerant in the primary flow path 10 or secondary flow path 20, a water quality sensor that measures the conductivity, turbidity, ion index, pH, etc. of the primary refrigerant or secondary refrigerant, a humidity sensor that measures the humidity inside the CDU 100, and a leak sensor that detects liquid leakage in the CDU 100.

[0049] The sensors are either arranged inside the primary flow path 10 or secondary flow path 20 or outside the primary flow path 10 or secondary flow path 20. As examples, those arranged inside the primary flow path 10 or secondary flow path 20 include the pressure sensors 112, 214 and the flow rate sensors 115, 216. Also, examples of those arranged outside the primary flow path 10 or secondary flow path 20 include a humidity sensor and a leak sensor. Note that the term "inside the primary flow path 10" as described in the present disclosure includes not only the locations where the primary refrigerant circulates but also the spaces fluidly connected to the primary flow path 10.

[0050] The above sensor is connected to the control unit 50 and can transmit the measurement results to the control unit 50. Further, the above sensor is connected to the control unit 50 in a hot-swappable manner and can be inserted and removed even when the CDU 100 is operating. Therefore, when an abnormality occurs in the sensor, the sensor can be maintained without stopping the CDU 100, and the impact on the server can be suppressed. By arranging a plurality of sensors of the same type in the vicinity, even when one sensor is removed, measurement in a nearby range can be continued.

[0051] In the CDU 100 configured as described above, when the valve 113 or the valve 121 does not operate for a certain period, deposits such as ionized metal or impurities that have accumulated may adhere to the valve 113 or the valve 121, and there is a risk that the valve 113 or the valve 121 will not operate normally. In addition, there is a possibility that an abnormality in the valve 113 and the valve 121 cannot be detected. Further, when the valve 113 or the valve 121 does not operate for a long time, it may adhere and malfunction.

[0052] Therefore, in the CDU 100 according to the first embodiment, when the valve 113 or the valve 121 does not operate for a certain time, the valve 113 or the valve 121 is made 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 at an early stage. Specifically, when the valve 113 or the valve 121 stops moving due to a failure and the temperature of the secondary refrigerant goes out of the threshold range, temperature adjustment of the secondary refrigerant becomes necessary after the failure is detected. On the other hand, according to the CDU 100 according to the first embodiment, the failure can be detected before such temperature adjustment becomes necessary. Hereinafter, the specific operation process of the CDU 100 will be described with reference to FIG. 2.

[0053] <Specific operation of CDU> FIG. 2 is a flowchart showing the procedure of the operation process of the first valve 113 executed by the CDU 100 according to the first embodiment.

[0054] First, the control unit 50 determines whether the period during which the first valve 113 is not operating 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 operating 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] Subsequently, the control unit 50 determines whether the liquid temperature of the secondary refrigerant is within a predetermined temperature range (step S103). When the control unit 50 determines that the liquid temperature of the secondary refrigerant is within the predetermined temperature range (step S103, Yes), it proceeds to step S104. On the other hand, when the control unit 50 determines that the liquid temperature of the secondary refrigerant is not within the predetermined temperature range (step S103, No), it ends the processing of this flow.

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

[0058] Subsequently, the control unit 50 determines whether the measured value of the pressure sensor 214 has changed significantly (step S105). For example, when the change in the measured value of the pressure sensor 214 is greater than the fluctuation range 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 has changed significantly.

[0059] When the measured value of the pressure sensor 214 has changed significantly (step S105, Yes), the control unit 50 proceeds to step S106. On the other hand, when the measured value of the pressure sensor 214 has not changed significantly (step S105, No), the control unit 50 ends the processing of this flow.

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

[0061] Subsequently, 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. Also, the control unit 50 may decrease the opening degree of the first valve 113. Further, the control unit 50 may cause the first valve 113 to perform an operation of increasing and decreasing the opening degree. Moreover, the control unit 50 may cause the first valve 113 to perform the operation of increasing and decreasing the opening degree a plurality of times. Here, it is desirable that the opening degree of the first valve 113 is the same before and after the predetermined operation. 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.

[0062] Here, when the first valve 113 does not perform the 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 notify an error using a display unit (not shown) such as a touch screen.

[0063] Subsequently, the control unit 50 checks the operation of the sensor (step S108). Specifically, the control unit 50 checks the operation 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 the predetermined operation, the control unit 50 checks whether there is a change in the measured value of the flow rate sensor 115. When there is a change in the measured value of the flow rate sensor 115, the control unit 50 determines that the flow rate sensor 115 is operating normally. On the other hand, when there is no change in the measured value of the flow rate sensor 115, the control unit 50 determines that the flow rate sensor is not operating normally and may notify an error using a display unit (not shown) such as a touch screen.

[0064] The control unit 50 may similarly check the operations of the flow rate sensor 216 or the pressure sensors 112 and 214. Further, the control unit 50 may similarly check 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 is not operating exceeds the threshold value, the control unit 50 of the CDU 100 according to the first embodiment causes the valve 113 to perform a predetermined operation.

[0066] By operating the valve 113 periodically in this way, deposits are less likely to adhere to the valve 113.

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

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

[0069] Here, it is desirable that the opening degrees of the other of the first valve 113 or the second valve 121 are the same before and after a predetermined operation of one of the first valve 113 or the second valve 121. 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 operating exceeds the threshold value and the liquid temperature of the secondary refrigerant acquired from the temperature sensors 211 and 215 is within a predetermined temperature range, the control unit 50 may cause the valve 113 to perform a predetermined operation. In other words, even when the period during which the valve 113 is not operating exceeds the threshold value, if the liquid temperature of the secondary refrigerant is outside the temperature range, it may not be necessary to cause the valve 113 to perform a predetermined operation.

[0071] When the liquid temperature of the secondary refrigerant is outside the temperature range, that is, when the liquid temperature of the secondary refrigerant needs to be adjusted, the operation is not performed in such a case. Thereby, the cooling performance of the CDU100 can be maintained. Further, condensation in the primary flow path 10 and the secondary flow path 20 can be suppressed.

[0072] The control unit 50 may determine whether to perform a predetermined operation according to the measured value of the pressure sensor 112 and the opening degree of the valve 113.

[0073] When deposits adhere to the valve 113, the pressure in the primary flow path 10 tends to increase. Therefore, by determining whether the valve 113 should operate based on the measured value of the pressure sensor 112 in the primary flow path 10, the progress of the adhesion of deposits to the valve 113 can be suppressed.

[0074] Further, the storage unit of the control unit 50 may include a plurality of threshold values for determining the period during which the valve 113 is not operating. The control unit 50 may select one threshold value from among the plurality of threshold values based on the measured value of the pressure sensor 112, and determine whether the period during which the valve 113 is not operating exceeds one threshold value. For example, when the measured value of the pressure sensor 112 is large, a threshold value with a small value may be selected from among the plurality of threshold values.

[0075] Thereby, when an upward trend in the internal pressure of the primary flow path 10 is observed, operation processing can be performed in a shorter period than usual, and the progress of the adhesion of deposits to the valve 113 can be suppressed.

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

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

[0078] Note that the same operation process as the flowchart of FIG. 2 may be performed on the second valve 121. FIG. 3 is a flowchart showing the operation process of the second valve 121 executed by the CDU 100 according to the first embodiment. Since it is the same as the flowchart of FIG. 2 except that the object on which the control unit 50 operates is different, detailed descriptions of each step are omitted.

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

[0080] Subsequently, in steps S202 and S203, the control unit 50 performs the same processing as steps S102 and S102 in FIG. 2.

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

[0082] Subsequently, the control unit 50 determines whether the opening degree of the second valve 121 and the measurement value of the pressure sensor 214 are within their respective threshold ranges (step S205). When the opening degree of the second valve 121 and the measurement value of the pressure sensor 214 are within their respective threshold ranges (step S205, Yes), the process proceeds to step S206. On the other hand, when the opening degree of the second valve 121 and the measurement value of the pressure sensor 214 are not within their respective threshold ranges (step S205, No), the processing of this flowchart ends.

[0083] Subsequently, the control unit 50 opens the first valve 113 (step S206) and causes the second valve 121 to perform a predetermined operation (step S207).

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

[0085] Note that the processing of this flow may be executed with a timing shift from the operation processing of the first valve 113 shown in FIG. 2. Thereby, 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 becomes difficult to affect the flow of the primary refrigerant, and an increase in the internal pressure in the primary flow path 10 can be suppressed.

[0086] Here, although an example in which operation processing is performed on the first valve 113 and the second valve 121 provided in the primary flow path 10 has been shown, the valves targeted for the operation processing are not limited to this. For example, operation processing may be performed on a valve (not shown) provided in the secondary flow path 20. Further, the arrangement location and the number of arranged valves are not limited to the example of FIG. 2.

[0087] Further, the control unit 50 may adjust the opening degree of the valve 113 or the valve 121 according to the measured value of the pressure sensor 214. According to such a configuration, an increase in the internal pressure in the primary flow path 10 can be suppressed.

[0088] Further, the control unit 50 may perform the processing shown in the flowchart of FIG. 2 above after closing the valve 113 or the valve 121. Since the internal pressure of the primary flow path 10 increases by closing the valves 113 and 121, deposits on the valve 113 or the valve 121 are more likely to be removed when the operation processing is performed.

[0089] Further, 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] Further, in step S105 of FIG. 2, the control unit 50 may further use the measured value of the flow rate sensor 115 to determine whether the change in the measured value of the pressure sensor 214 is large.

[0091] As described above, when the period in which the valve 113 is not operating exceeds the threshold value, the control unit 50 of the CDU 100 according to the first embodiment causes the valve 113 to perform a predetermined operation. By operating the valve 113 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 two two-way valves, valve 113 and valve 121, are provided in the primary flow path 10 has been described. However, the types of valves are not limited to this. Instead of the two two-way valves, one three-way valve may be provided in the primary flow path 10. FIG. 4 is a diagram showing a schematic configuration of the CDU 100 according to the second embodiment.

[0093] Valve 19 is provided at the branch point between 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. Valve 19 is, for example, an electromagnetic three-way valve. The opening degree of valve 19 can be adjusted by the control unit 50.

[0094] 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 can adjust 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 can be adjusted.

[0095] By adopting a configuration in which one three-way valve is provided in the primary flow path 10 in this way, the number of valves used can be reduced, and the cost can be lowered.

[0096] (Other Embodiments) <Operation Process of Pump> Since the CDU 100 of the present disclosure includes a plurality of pumps 231, 241 (see FIG. 1), it is possible to operate only one of the plurality of pumps 231, 241 and make the other pumps standby. When the standby pump does not operate for a certain period, it is possible to perform the operation process in the same manner as the first valve 113 and the second valve 121.

[0097] <Removal of Deposits by Opening and Closing of Valve> Sediments may accumulate on the members and flow path pipes disposed 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 disposed in the flow path pipe, the function of the sensor may be restricted due to the accumulation of sediments around the sensor. Further, when sediments accumulate at a location with high flow path resistance (a bent location or a location where the flow path is narrow) in the primary flow path 10 or the secondary flow path 20, the flow path resistance may further increase, which may affect the circulation of the primary refrigerant or the secondary refrigerant.

[0098] Therefore, as shown in FIG. 1, when a valve 113 or a valve 121 is disposed in the primary flow path 10, by repeatedly opening and closing the valve 113 or the valve 121, turbulent flow can be generated near the valve 113 or the valve 121, and the deposited sediments can be peeled off from the fixing position and circulated in the flow path. Further, by providing a mesh-shaped filter in the primary flow path 10, the sediments can be stopped by the filter, and the re - adhesion to other members can be suppressed. The filter is removable from the primary flow path 10, and when the filter is clogged, it can be removed for maintenance. The opening and closing speed of the valve 113 or the valve 121 for generating the turbulent flow is faster than the opening and closing speed of the valve 113 or the valve 121 for adjusting the amount of refrigerant flowing through the primary flow path 10.

[0099] The timing for generating turbulent flow to flush the sediments can be performed in conjunction with the operation process of the valve 113 or the valve 121 described above in the first embodiment. Also, it can be carried out at the timing when the influence of the sediments is detected from the measured value of the sensor (for example, the flow rate measured by the flow rate sensors 115, 216), or the rotation speed of the pumps 231, 241, etc.

[0100] By increasing the turbulent flow or creating an impact flow, it becomes possible to flush large-volume deposits or strongly adhered deposits. Examples of methods for increasing the turbulent flow or creating an impact flow include increasing the opening and closing speed of valve 113 or valve 121, increasing the number of opening and closing cycles, and increasing the flow rate of the circulating primary refrigerant. Note that this process may also be performed on the valves provided in the secondary flow path 20.

[0101] <Removal of Deposits by Pump Operation> As shown in FIG. 1, when pump 231 or pump 241 is disposed in the primary flow path 10, it is possible to generate turbulent flow by adjusting the rotation of pump 231 or pump 241. Turbulent flow can be caused by repeating the rotation, stop, or reverse rotation of pump 231 or pump 241.

[0102] Note that the change in the rotation speed of pump 231 or pump 241 for causing the above-mentioned turbulent flow is greater than the change in the rotation speed of pump 231 or pump 241 for adjusting the amount of refrigerant flowing through the primary flow path 10 and the secondary flow path 20. Examples of increasing the turbulent flow or creating an impact flow include increasing the rotation speed of pump 231 or pump 241, sudden stop, or increasing the amount of circulating refrigerant.

[0103] <Self-Diagnosis Function of Each Member> Members disposed in the CDU 100 and connected to the control unit 50 can notify the control unit 50 when an abnormality occurs. Further, each member can self-diagnose the period until maintenance is required by recording the operating status or maintenance frequency, etc. For example, valves 113, 121 or pumps 231, 241 are examples of members that can be self-diagnosed, but it is also possible to provide a self-diagnosis function for members not described.

[0104] The valve 113 or valve 121 has a function of self-diagnosing the timing when maintenance is required based on operation detection during the operation process of the valve 113 or valve 121 shown in the first embodiment, the number of openings and closings since the previous maintenance, the cumulative change amount, and the continuous operation time.

[0105] The pump 231 or pump 241 has a function of self-diagnosing the timing when maintenance is required based on operation detection during the operation process of the pump 231 or pump 241 described above, or the cumulative number of rotations since the previous maintenance, the frequency of change in rotational speed, the number of starts and stops, etc. Further, as an index of the period until maintenance, a comparison of the number of rotations at the same duty ratio stored in the storage unit can be performed, and the ratio of change can be used. Also, it is possible to determine whether the pump 231 or pump 241 is normal by comparing the operating sound during normal operation or the operating sound during abnormal operation.

[0106] <Cleaning flow path> Detachable couplers (quick fluid connectors) are provided in the primary flow path 10 and the secondary flow path 20 within the CDU 100, and by disconnecting the couplers, it becomes possible to disconnect a specific part from the primary flow path 10 and the secondary flow path 20. 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 or the secondary flow path 20. When scale (water 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 fixes, by disconnecting the coupler, the heat exchanger 40 is disconnected and an external connection coupler connected to the cleaning flow path is attached, and thus strong acid or the like can be flowed from the cleaning flow path to clean the scale.

[0107] What is used for cleaning is not limited to strong acid, and it is also possible to use an alkaline liquid or a liquid having other properties. Also, it is not limited to liquids, and cleaning by gas collision, powder, or pellets can also be used.

[0108] As a form other than separation from the flow path by the coupler, it is also possible to provide a cleaning flow path by providing a valve (for example, a three-way valve or a combination of two two-way valves, etc.) capable of switching 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 separate the circulation flow path and the cleaning flow path by operating the three-way valves.

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

[0111] In the above description, the heat exchanger 40 of the CDU100 is described, but it may be a member other than the heat exchanger 40. Furthermore, members other than the CDU100 (for example, closed water cooling composed of a radiator, a water-cooled head, etc.) can have the same configuration.

[0112] In addition, the present technology can also adopt the following configuration. (1) A primary flow path through which a primary refrigerant flows, A secondary flow path through which a secondary refrigerant flows, A valve provided in the primary flow path or the secondary flow path and capable of adjusting the opening degree, A control unit that controls the operation of the valve and The control unit causes the valve to perform a predetermined operation when the period during which the valve is not operating exceeds a threshold value, a refrigerant circulation device. (2) Further comprising a heat exchanger connected to the primary flow path and the secondary flow path, The primary flow path is A main flow path that connects the inlet and outlet of the primary refrigerant via the heat exchanger; 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; and includes; The valve is; A first valve that connects to the main flow path at a position downstream of the branch position of the bypass flow path in the main flow path and upstream of the heat exchanger; A second valve that connects to the bypass flow path; and includes; The control unit opens the other of the first valve or the second valve while one of the first valve or the second valve is performing the predetermined operation. The refrigerant circulation device according to (1). (3) Further includes a temperature sensor provided in the secondary flow path; When the period during which the valve is not operating exceeds a threshold value and the liquid temperature of the secondary refrigerant acquired from the temperature sensor is within a predetermined temperature range, the control unit causes the valve to perform the predetermined operation. The refrigerant circulation device according to (1) or (2). (4) Further includes a pressure sensor provided in the primary flow path; The control unit determines whether to perform the predetermined operation according to the measured value of the pressure sensor and the opening degree of the valve. The refrigerant circulation device according to any one of (1) to (3). (5) Further includes a sensor provided in the primary flow path or the secondary flow path; The control unit checks whether the sensor is operating normally based on the change in the measured value of the sensor during the predetermined operation. The refrigerant circulation device according to any one of (1) to (4).

[0113] The embodiments disclosed herein should be considered illustrative in all respects and not restrictive. Indeed, the above embodiments can be embodied in various forms. Also, the above embodiments may be omitted, substituted, or changed in various forms without departing from the scope and spirit of the appended claims.

Explanation of Reference Numerals

[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 sensor 115, 216 Flow rate sensor 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 sensor 113 First valve 121 Second valve 231, 241 Pump 232, 242 Check valve

Claims

1. a primary flow path through which a primary refrigerant flows; a secondary flow path through which a secondary refrigerant flows; a valve provided in the primary flow path or the secondary flow path and capable of adjusting an opening degree; A control unit for controlling the operation of the valve; Equipped with The control unit causes the valve to perform a predetermined operation when a period during which the valve is not operating exceeds a threshold value.

2. a heat exchanger connected to the primary flow path and the secondary flow path, The primary flow path is a main flow path connecting an inlet and an outlet of the primary refrigerant via the heat exchanger; 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; Including, The valve is a first valve connected to the main flow path at a position downstream of a branch position of the bypass flow path in the main flow path and upstream of the heat exchanger; a second valve connected to the bypass flow path; Including, The refrigerant circulation device according to claim 1 , wherein the control unit opens the other of the first valve or the second valve while one of the first valve or the second valve is performing the predetermined operation.

3. A temperature sensor is provided in the secondary flow path, 2. The refrigerant circulation device according to claim 1, wherein the control unit causes the valve to perform the predetermined operation when a period during which the valve is not operating exceeds a threshold value and when a liquid temperature of the secondary refrigerant acquired from the temperature sensor is within a predetermined temperature range.

4. A pressure sensor is provided in the primary flow path, The refrigerant circulation device according to claim 1 , wherein the control unit determines whether to perform the predetermined operation depending on a measurement value of the pressure sensor and an opening degree of the valve.

5. Further comprising a sensor provided in the primary flow path or the secondary flow path, The refrigerant circulation device according to claim 1 , wherein the control unit checks 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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