Refrigerant circulation system

Abstract

The present invention provides a refrigerant circulation system that can supply an appropriate flow rate of refrigerant to each of multiple cooling targets individually. [Solution] An exemplary embodiment of the refrigerant circulation system comprises a plurality of first heat exchange units, a second heat exchange unit, a first flow path, and a second flow path. A first heat exchange unit is provided for each object to be cooled. The second heat exchange unit is equipped with a heat exchanger. The first flow path distributes refrigerant from the second heat exchange unit to the plurality of first heat exchange units. The second flow path combines the refrigerants returned from the plurality of first heat exchange units and recovers them in the second heat exchange unit. Each first heat exchange unit is equipped with a pump. The pump sends the refrigerant supplied from the first flow path to the cooling section that cools the object to be cooled by the refrigerant, and then sends it to the second flow path.

Description

Technical Field

[0001] The disclosed embodiments relate to a refrigerant circulation system.

Background Art

[0002] There is a refrigerant circulation system that supplies refrigerant from one refrigerant circulation device to a plurality of racks in which cooling targets are housed to cool the cooling targets.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the refrigerant circulation systems described in the prior art documents, it is difficult to supply an appropriate flow rate of refrigerant individually to each of the plurality of cooling targets.

[0005] One aspect of the embodiment has been made in view of the above, and an object thereof is to provide a refrigerant circulation system capable of supplying an appropriate flow rate of refrigerant individually to each of the plurality of cooling targets.

Means for Solving the Problems

[0006] An exemplary embodiment of the refrigerant circulation system comprises a plurality of first heat exchange units, a second heat exchange unit, a first flow path, and a second flow path. Each first heat exchange unit is provided for each object to be cooled. Each second heat exchange unit includes a heat exchanger. The first flow path distributes refrigerant from the second heat exchange unit to the plurality of first heat exchange units. The second flow path combines the refrigerant returned from the plurality of first heat exchange units and recovers it in the second heat exchange unit. Each first heat exchange unit includes a pump. The pump causes each first heat exchange unit to pass the refrigerant supplied from the first flow path to a cooling section that cools the object to be cooled by the refrigerant, and then send it to the second flow path. [Effects of the Invention]

[0007] An exemplary refrigerant circulation system can supply an appropriate flow rate of refrigerant to each of a plurality of cooling targets individually. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is an explanatory diagram showing a refrigerant circulation system according to an exemplary embodiment. [Figure 2] Figure 2 is an explanatory diagram showing a refrigerant circulation system according to a first modified example of an exemplary embodiment. [Figure 3] Figure 3 is an explanatory diagram showing a refrigerant circulation system according to a second modified example of an exemplary embodiment. [Figure 4] Figure 4 is an explanatory diagram showing a refrigerant circulation system according to a third modified example of an exemplary embodiment. [Figure 5] Figure 5 is an explanatory diagram showing a refrigerant circulation system according to a modified example 4 of the exemplary embodiment. [Modes for carrying out the invention]

[0009] Hereinafter, exemplary embodiments of the refrigerant circulation system will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments described below. Furthermore, in the following description, the same reference numerals are used for the same components to omit redundant explanations. The refrigerant circulation system according to the embodiment is a system that cools an object to be cooled by circulating a refrigerant.

[0010] The objects to be cooled are, in one example, server equipment housed in a server rack or electronic devices such as CPUs (Central Processing Units) that generate heat during operation. One object to be cooled may be a single electronic device or may include multiple electronic devices.

[0011] Figure 1 is an explanatory diagram showing a refrigerant circulation system 2 according to an exemplary embodiment. The refrigerant circulation system 2 includes a plurality (in this case, two) first heat exchange units 3 (31, 32), a second heat exchange unit 4, and a cooling tower 5. A first heat exchange unit 3 is provided for each object to be cooled 8.

[0012] In one example, the first heat exchange unit 3 is installed in each rack that houses the cooling target 8. The first heat exchange units 31 and 32 have the same configuration. For this reason, Figure 1 omits the illustration of the internal configuration of the housing 9 of the first heat exchange unit 32, which will be described later.

[0013] The second heat exchange unit 4 is provided separately from the first heat exchange unit 3. In one example, the second heat exchange unit 4 is provided outside the rack in which the object to be cooled 8 is housed. The second heat exchange unit 4 includes a heat exchanger 41. Each of the first heat exchange units 3 and the second heat exchange unit 4 is connected by a first flow path 6 and a second flow path 7 through which a refrigerant flows.

[0014] The first flow path 6 is a refrigerant flow path that distributes refrigerant from the second heat exchange unit 4 to multiple first heat exchange units 3. The second flow path 7 is a refrigerant flow path that combines the refrigerants returned from multiple first heat exchange units 3 and recovers them in the second heat exchange unit 4.

[0015] The second heat exchange unit 4 and the cooling tower 5 are connected by a refrigerant circulation channel 51. The cooling tower 5 sends the primary refrigerant it cools internally to the heat exchanger 41 of the second heat exchange unit 4 through the circulation channel 51, and cools the primary refrigerant returning from the heat exchanger 41 again before sending it back to the heat exchanger 41.

[0016] The first heat exchange unit 3 is equipped with pumps 14 to 16 that pass the secondary refrigerant supplied from the first flow path 6 through the cooling section 11 and send it to the second flow path 7. In this way, the secondary refrigerant is sent from the first flow path 6 to the cooling section 11 by pumps 14 to 16.

[0017] Subsequently, the secondary refrigerant cools the object to be cooled 8 by absorbing heat from it as it passes through the cooling section 11, and then is sent to the second flow path 7 and returned to the heat exchanger 41 of the second heat exchange unit 4. As the secondary refrigerant passes through the heat exchanger 41, it is cooled by the cooled primary refrigerant circulating in the circulation flow path 51, and is again supplied to each first heat exchange unit 3 through the first flow path 6. Here, we describe the case in which the secondary refrigerant is cooled by the primary refrigerant supplied from the cooling tower 5 to the heat exchanger 41, but this is just one example. In this exemplary embodiment, the secondary refrigerant may be cooled by other cooling devices such as a fan or a radiator.

[0018] In this way, the refrigerant circulation system 2 cools the object to be cooled 8. In Figure 1, the flow path of the secondary refrigerant before it absorbs heat from the object to be cooled 8 is shown by a thick solid line, and the flow path of the secondary refrigerant after it absorbs heat from the object to be cooled 8 is shown by a thick dotted line. In Figure 1, the circulation flow path 51 of the primary refrigerant circulating between the cooling tower 5 and the second heat exchange unit 4 is also shown by a thick solid line.

[0019] As described above, in the refrigerant circulation system 2, each of the first heat exchange units 3 includes pumps 14 to 16. Therefore, when the heat generation amount varies for each cooling target 8 and the required cooling performance changes in the refrigerant circulation system 2, the outputs of the pumps 14 to 16 are adjusted for each first heat exchange unit 3, enabling the provision of the secondary refrigerant with an optimal flow rate to each cooling target 8.

[0020] Hereinafter, the configuration of the first heat exchange unit 3 will be specifically described. The first heat exchange unit 3 includes a housing 9 in which pumps 14 to 16 and the like are housed, manifolds 10A and 10B, a cooling unit 11, a temperature sensor 28, and the like.

[0021] Inside the housing 9, at least a part of the forward path 61 of the secondary refrigerant through which the secondary refrigerant is sent from the first flow path 6 to the cooling unit 11 is located. Further, the return path 71 of the secondary refrigerant through which the secondary refrigerant is sent from the cooling unit 11 to the second flow path 7 is located outside the housing 9. Thereby, the refrigerant circulation system 2 can simplify the piping inside the housing 9 as compared with the case where the forward path 61 and the return path 71 of the secondary refrigerant are located inside the housing 9.

[0022] Furthermore, inside the housing 9, filters 12 and 13, pumps 14 to 16, CKVs (check valves) 17 to 19, a first valve 20, a second valve 21, a flow rate sensor 22, a temperature sensor 23, an expansion tank 24, a power supply IC 25, and a controller 26 are located.

[0023] The filters 12 and 13 are connected in parallel between the first flow path 6 and the pumps 1s4 to 16. The first valve 20 is located between the first flow path 6 and the filters 12 and 13. The first valve 20 includes an inlet of the secondary refrigerant connected to the first flow path 6, an outlet of the secondary refrigerant connected to the filter 12, and an outlet of the secondary refrigerant connected to the filter 13. The first valve 20 is a valve capable of switching the flow path for sending the secondary refrigerant supplied from the first flow path 6 to either one of the filter 12 or the filter 13.

[0024] The second valve 21 is located between the filters 12 and 13 and the pumps 14 to 16. The second valve 21 has a secondary refrigerant inlet connected to the filter 12, a secondary refrigerant inlet connected to the filter 13, and a secondary refrigerant outlet connected to the pumps 14 to 16. The second valve 21 is a valve that can switch the flow path for sending the secondary refrigerant supplied from either the filter 12 or the filter 13 to the pumps 14 to 16.

[0025] In the refrigerant circulation system 2, the secondary refrigerant can be circulated by passing it through one of the filters 12 and 13, and not passing it through the other. This allows the refrigerant circulation system 2 to replace the filter that does not pass the secondary refrigerant, even while the system is in operation.

[0026] Furthermore, pumps 14-16 are connected in parallel to the supply path 61. This allows the refrigerant circulation system 2 to continue operating even if one of the pumps 14-16 fails, thanks to the other pumps that are not malfunctioning. Note that CKV17-19 are check valves connected to the output side of pumps 14-16.

[0027] Furthermore, the expansion tank 24 is connected to a distribution channel 27 that distributes secondary refrigerant to pumps 14-16, which are connected in parallel from the first flow path 6. The expansion tank 24 is a tank whose internal pressure can be adjusted. When the internal pressure of the forward flow path 61 exceeds a predetermined value, the expansion tank 24 allows secondary refrigerant to flow into it from the distribution channel 27, adjusting the internal pressure of the forward flow path 61 to be below the predetermined value. The refrigerant circulation system 2 can further suppress cavitation inside the forward flow path 61 by providing the expansion tank 24 near the inlet of the secondary refrigerant in the pumps 14-16, which tend to become negative pressure.

[0028] Furthermore, the flow sensor 22 and temperature sensor 23 are connected between CKV17~19 and manifold 10A in the supply path 61. The flow sensor 22 detects the flow rate of the secondary refrigerant flowing through the supply path 61 and outputs the detection result to the controller 26. The temperature sensor 23 detects the temperature of the secondary refrigerant sent from pumps 14~16 to the cooling unit 11 and outputs the detection result to the controller 26.

[0029] Manifold 10A delivers the secondary refrigerant supplied from the forward path 61 to the cooling unit 11. In one example, the cooling unit 11 is a cooling plate through which the secondary refrigerant flows. If the cooling target 8 includes multiple electronic devices, a cooling unit 11 may be provided for each electronic device.

[0030] In this case, the manifold 10A distributes the secondary refrigerant to each cooling unit 11. If a liquid immersion cooling method is adopted, the cooling unit 11 becomes a cooling tank in which the electronic equipment to be cooled 8 is immersed in the secondary refrigerant.

[0031] Manifold 10B sends the secondary refrigerant that has passed through the cooling unit 11 to the return path 71. If the cooling target 8 includes multiple electronic devices, manifold 10B combines the secondary refrigerants flowing in from each cooling unit 11 provided for each electronic device and sends them to the return path 71.

[0032] The temperature sensor 28, located outside the housing 9, is connected between the manifold 10B and the second flow path 7 in the return path 71. The temperature sensor 28 detects the temperature of the secondary refrigerant sent from the cooling unit 11 to the second flow path 7 and outputs the detection result to the controller 26. In this way, the first heat exchange unit 3 is equipped with a temperature sensor 28 that detects the temperature of the secondary refrigerant after it has passed through the cooling unit 11. This allows the controller 26 to confirm whether the cooling performance of the first heat exchange unit 3 is sufficient based on the temperature of the secondary refrigerant detected by the temperature sensor 28.

[0033] The power supply IC 25 supplies power to the controller 26, pumps 14-16, flow sensor 22, and temperature sensors 23 and 28. If the first valve 20 and second valve 21 are solenoid valves, the power supply IC 25 also supplies power to the first valve 20 and second valve 21.

[0034] The controller 26 includes a microcomputer with a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and various circuits. The controller 26 comprehensively controls the operation of the first heat exchange unit 3 by having the CPU execute a program stored in ROM, using the RAM as a working area.

[0035] The controller 26 adjusts the flow rate of pumps 14-16 according to the temperature of the secondary refrigerant detected by the temperature sensor 28. For example, when the temperature of the secondary refrigerant detected by the temperature sensor 28 exceeds a first threshold, the controller 26 increases the flow rate of pumps 14-16 until the temperature of the secondary refrigerant falls below the first threshold. In addition, if the temperature of the secondary refrigerant becomes too low, the controller 26 can suppress condensation by reducing the flow rate of pumps 14-16. The first threshold can be arbitrarily set by the user.

[0036] As a result, for example, when the heat generation of the cooling target 8 increases, the controller 26 of the first heat exchange unit 31 can individually increase the flow rate of the secondary refrigerant in the first heat exchange unit 31 and supply an appropriate flow rate of secondary refrigerant to the cooling unit 11.

[0037] Furthermore, the controller 26 may be configured to adjust the flow rate of pumps 14 to 16 according to the temperature of the secondary refrigerant before and after passing through the cooling section 11. In this case, the controller 26 calculates the temperature difference by subtracting the temperature of the secondary refrigerant detected by the temperature sensor 28 provided in the forward path 61 from the temperature of the secondary refrigerant detected by the temperature sensor 23 provided in the return path 71.

[0038] Then, when the calculated temperature difference exceeds the second threshold, the controller 26 increases the flow rate of pumps 14-16 until the temperature difference falls below the second threshold. As a result, even if the temperature of the secondary refrigerant flowing through the return path 71 rises, the controller 26 does not unnecessarily increase the flow rate of pumps 14-16, thus suppressing an increase in the power consumption of pumps 14-16.

[0039] For example, in the first heat exchange unit 31, the temperature of the secondary refrigerant flowing through the return path 71 may rise not due to the heat of the object being cooled 8 in the first heat exchange unit 31, but rather due to a deterioration in the heat exchange performance of the second heat exchange unit 4, or due to the object being cooled 8 in another first heat exchange unit 32.

[0040] In this case, the controller 26 determines that the temperature of the secondary refrigerant flowing in the forward path 61 has also risen, and even if the flow rate of the pumps 14-16 of the first heat exchange unit 31 is increased, the temperature of the secondary refrigerant flowing in the return path 71 cannot be lowered. Therefore, in such cases, the controller 26 can provide optimal cooling performance while minimizing the power consumption of the pumps 14-16 by not unnecessarily increasing the flow rate of the pumps 14-16.

[0041] Next, with reference to Figure 2, a refrigerant circulation system 2A according to a first modified example of an exemplary embodiment will be described. Figure 2 is an explanatory diagram showing a refrigerant circulation system 2A according to a first modified example of an exemplary embodiment.

[0042] As shown in Figure 2, the refrigerant circulation system 2A according to the first modified example differs from the second heat exchange unit 4 shown in Figure 1 in the configuration of the second heat exchange unit 4A, while the other configurations are the same as those of the refrigerant circulation system 2 shown in Figure 1. Furthermore, the internal configuration of the housing 9 in the first heat exchange units 31 and 32 shown in Figure 2 is the same as the internal configuration of the housing 9 in the first heat exchange unit 31 shown in Figure 1.

[0043] The heat exchanger 41 of the second heat exchange unit 4A is configured to be removable from the second heat exchange unit 4A. This makes it easy to adjust the cooling performance of the refrigerant circulation system 2A by replacing the heat exchanger 41 with one that has different heat exchange performance.

[0044] Furthermore, since the refrigerant circulation system 2A can be replaced with a different heat exchanger 41, maintenance can be easily performed by removing the heat exchanger 41. During this time, by installing another heat exchanger 41 on the second heat exchange unit 4A and operating it, maintenance of the heat exchanger 41 can be performed while the refrigerant circulation system 2A is running.

[0045] Next, with reference to Figure 3, a refrigerant circulation system B according to a second modified example of the exemplary embodiment will be described. Figure 3 is an explanatory diagram showing a refrigerant circulation system 2B according to a second modified example of the exemplary embodiment.

[0046] As shown in Figure 3, the refrigerant circulation system 2B according to the second modification differs from the second heat exchange unit 4 shown in Figure 1 in the configuration of the second heat exchange unit 4B, while the other configurations are the same as those of the refrigerant circulation system 2 shown in Figure 1. The internal configuration of the housing 9 in the first heat exchange units 31 and 32 shown in Figure 2 is the same as the internal configuration of the housing 9 in the first heat exchange unit 31 shown in Figure 1.

[0047] The second heat exchange unit 4B includes a plurality of heat exchangers 41. The plurality of heat exchangers 41 are connected in parallel to the first flow path 6 and the second flow path 7 via a manifold 29. Furthermore, the plurality of heat exchangers 41 are connected in parallel to the cooling tower 5 via a manifold 30. In the example shown in Figure 3, the second heat exchange unit 4B includes two heat exchangers 41, but it may include three or more heat exchangers 41. The manifold 29 has the function of distributing the secondary refrigerant flowing in from the second flow path 7 to the plurality of heat exchangers 41, and the function of collecting the secondary refrigerant flowing in from the plurality of heat exchangers 41 and releasing it into the first flow path 6. The manifold 30 has the function of collecting the secondary refrigerant flowing in from the plurality of heat exchangers 41 and releasing it into the cooling tower 5, and the function of distributing the secondary refrigerant flowing in from the cooling tower 5 to the plurality of heat exchangers 41.

[0048] As a result, the redundancy of the heat exchangers 41 is improved, as the second heat exchange unit 4B can cool the secondary refrigerant with the other heat exchangers 41 even if some of the heat exchangers 41 fail. Furthermore, the heat exchange performance of the second heat exchange unit 4B can be easily adjusted by changing the number of heat exchangers 41 that are operated simultaneously.

[0049] Next, with reference to Figure 4, a refrigerant circulation system 2C according to a third modified example of the exemplary embodiment will be described. Figure 4 is an explanatory diagram showing a refrigerant circulation system 2C according to a third modified example of the exemplary embodiment.

[0050] As shown in Figure 4, the refrigerant circulation system 2C according to the third modified example differs from the refrigerant circulation system 2 shown in Figure 1 in that it includes a plurality of second heat exchange units 4. The other components of the refrigerant circulation system 2C are the same as those of the refrigerant circulation system 2 shown in Figure 1.

[0051] Multiple second heat exchange units 4 are connected in parallel to the first flow path 6 and the second flow path 7 via a manifold 29. Furthermore, multiple second heat exchange units 4 are connected in parallel to the cooling tower 5 via a manifold 30. In the example shown in Figure 4, the refrigerant circulation system 2C has two second heat exchange units 4, but it may have three or more second heat exchange units 4.

[0052] As a result, the refrigerant circulation system 2C can cool the secondary refrigerant by other second heat exchange units 4 even if some second heat exchange units 4 fail, thus improving the redundancy of the second heat exchange units 4. Furthermore, the refrigerant circulation system 2C can easily adjust the heat exchange performance by changing the number of second heat exchange units 4 that are operating simultaneously.

[0053] Up to this point, we have described the case where each first heat exchange unit 3 is equipped with a controller 26, but the controller 26 may be provided in any one of the first heat exchange units 3. The controller 26 is connected to each first heat exchange unit 3 in a communication manner.

[0054] The controller 26 then adjusts the flow rate of the pumps 14-16 of each first heat exchange unit 3 according to the temperature of the secondary refrigerant after it has passed through the cooling section 11, as detected by the temperature sensor 28 located in the return path 71 of each first heat exchange unit 3.

[0055] As a result, the refrigerant circulation systems 2, 2A, 2B, and 2C do not require a controller 26 for any first heat exchange unit 3 other than the one first heat exchange unit 3 that is equipped with a controller 26. Therefore, the refrigerant circulation systems 2, 2A, 2B, and 2C can supply an appropriate flow rate of secondary refrigerant to each of the multiple cooling targets 8 individually while suppressing cost increases.

[0056] Furthermore, the controller 26 can provide optimal cooling performance for each cooling target 8 by controlling each first heat exchange unit 3 (31, 32, etc.) collectively. For example, because the flow rate that can flow through the first flow path 6 and the second flow path 7 is limited due to pressure loss, the controller 26 can efficiently cool the cooling target 8 by prioritizing the first heat exchange units 3 and sending secondary refrigerant to each first heat exchange unit 3.

[0057] Next, with reference to Figure 5, a refrigerant circulation system 2D according to a fourth modified example of the exemplary embodiment will be described. Figure 5 is an explanatory diagram showing a refrigerant circulation system 2D according to a fourth modified example of the exemplary embodiment.

[0058] As shown in Figure 5, the refrigerant circulation system 2D according to the fourth modified example differs from the refrigerant circulation system 2 shown in Figure 1 in that each first heat exchange unit 3 (31, 32) is equipped with multiple housings 9. The other configurations of the refrigerant circulation system 2D are the same as those of the refrigerant circulation system 2 shown in Figure 1.

[0059] The internal configuration of each housing 9 is the same as the internal configuration of housing 9 shown in Figure 1. Secondary refrigerant is supplied to each housing 9 from the first flow path 6. Secondary refrigerant is supplied from each housing 9 to the manifold 10A. As a result, the refrigerant circulation system 2D has improved redundancy because, for example, even if a component inside one housing 9 fails, secondary refrigerant can be supplied to the cooling unit 11 from another housing 9 via the manifold 10A.

[0060] Furthermore, the technologies relating to the first to fourth modifications can be combined in any way. For example, the second heat exchange unit 4A of the refrigerant circulation system 2A relating to the first modification may be provided in multiple quantities and connected in parallel to the first flow path 6 and the second flow path 7.

[0061] Furthermore, the second heat exchange unit 4A of the refrigerant circulation system 2A according to the first modified example may include a plurality of heat exchangers 41. In this case, the plurality of heat exchangers 41 may be connected in parallel to the first flow path 6 and the second flow path 7.

[0062] Furthermore, the heat exchanger 41 of the refrigerant circulation system 2B according to the second modification may be insertable into and removable from the second heat exchange unit 4B. Also, multiple second heat exchange units 4B may be provided in the refrigerant circulation system 2B according to the second modification. In this case, multiple second heat exchange units 4B may be connected in parallel to the first flow path 6 and the second flow path 7.

[0063] Furthermore, the heat exchangers 41 provided in each second heat exchange unit 4 of the refrigerant circulation system 2C according to the third modified example may be configured to be insertable and removable from the second heat exchange unit 4. Also, each second heat exchange unit 4 of the refrigerant circulation system 2C according to the third modified example may be provided with multiple heat exchangers 41. In this case, the multiple heat exchangers 41 may be connected in parallel to the first flow path 6 and the second flow path 7. In addition, the first heat exchange unit 3 shown in Figures 1 to 4 may be replaced with a first heat exchange unit provided with multiple housings 9 according to the fourth modified example.

[0064] Furthermore, the pumps 14 to 16 inside the housing 9 according to the exemplary embodiment described above may be configured to be hot-swappable. This allows the refrigerant circulation systems 2, 2A, 2B, 2C, and 2D according to the exemplary embodiment to be continuously operable and improve maintainability. Additionally, the housing 9 inside the first heat exchange unit 3 may be configured to be hot-swappable. This improves the maintainability of the components inside the housing 9 in the refrigerant circulation systems 2, 2A, 2B, 2C, and 2D according to the exemplary embodiment.

[0065] Furthermore, the first flow path 6 and the second flow path 7 and the first heat exchange unit 3 may be connected by a coupling, and the first heat exchange unit 3 may be configured to be disconnected from the first flow path 6 and the second flow path 7. This makes it easy to replace the first heat exchange unit 3 in the refrigerant circulation systems 2, 2A, 2B, 2C, and 2D according to the exemplary embodiment. In addition, by using a coupling, even when any of the first heat exchange units 3 is removed, there is no concern about leakage of secondary refrigerant, and secondary refrigerant can be sent to other first heat exchange units through the first flow path 6.

[0066] Furthermore, this technology can be configured as follows: (1) Multiple first heat exchange units are provided for each object to be cooled, A second heat exchange unit equipped with a heat exchanger, A first flow path for distributing refrigerant from the second heat exchange unit to the plurality of first heat exchange units, A second flow path that combines the refrigerant returned from the plurality of first heat exchange units and recovers it in the second heat exchange unit. Equipped with, Each of the first heat exchange units is equipped with a pump that passes the refrigerant supplied from the first channel to the cooling section that cools the object to be cooled by the refrigerant, and sends it to the second channel. Refrigerant circulation system. (2) The first heat exchange unit includes a housing that houses the pump, At least a portion of the forward path of the refrigerant, from the first flow path to the cooling section, is located inside the housing. The return path of the refrigerant, which is sent from the cooling unit to the second flow path, is located outside the housing. The refrigerant circulation system described in (1) above. (3) The heat exchanger is removable from the second heat exchange unit. The refrigerant circulation system described in (1) or (2) above. (4) The second heat exchange unit comprises a plurality of heat exchangers connected in parallel to the first and second flow paths. A refrigerant circulation system as described in any one of (1) to (3) above. (5) The system comprises multiple second heat exchange units. A refrigerant circulation system as described in any one of (1) to (4) above. (6) A plurality of filters are connected in parallel between the first flow path and the pump, The system includes a first valve located between the first flow path and the filter, and a second valve located between the filter and the pump. A refrigerant circulation system as described in any one of (1) to (5) above. (7) The first heat exchange unit is A distribution channel for distributing refrigerant to a plurality of pumps connected in parallel from the first channel, It comprises an expansion tank connected to the distribution channel and capable of adjusting its internal pressure. A refrigerant circulation system as described in any one of (1) to (6) above. (8) Each of the first heat exchange units is A temperature sensor for detecting the temperature of the refrigerant sent from the cooling unit to the second flow path, The system includes a controller that adjusts the flow rate of the pump according to the temperature of the refrigerant detected by the temperature sensor. A refrigerant circulation system as described in any one of (1) to (7) above. (9) The system further includes a temperature sensor for detecting the temperature of the refrigerant delivered from the pump to the cooling unit. The controller adjusts the flow rate of the pump according to the temperature of the refrigerant before and after it passes through the cooling section. The refrigerant circulation system described in (8) above. (10) Each of the first heat exchange units is connected to a controller that adjusts the flow rate of the pump in each of the first heat exchange units according to the temperature of the refrigerant after it has passed through the cooling section of each of the first heat exchange units. The refrigerant circulation system described in (8) or (9) above.

[0067] Further effects and modifications can be readily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the specific details and representative embodiments expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents. [Explanation of Symbols]

[0068] 2,2A,2B,2C,2D Refrigerant Circulation System 3(31,32) First heat exchange unit 4,4A,4B Second heat exchange unit 5 cooling tower 6. First channel 7. Second channel 8. Items to be cooled 9 cabinets 10A, 10B, 29, 30 Manifold 11 Cooling section 12,13 Filters 14-16 Pumps 20. Valve No. 1 21. Second valve 22 Flow Sensor 23,28 Temperature Sensor 24 Expansion Tank 26 Controllers 27 Distribution channel 41 Heat exchanger 51 Circulation channel 61 Outbound journey 71 Return trip 25 Power IC

Claims

1. Multiple first heat exchange units are provided for each object to be cooled, A second heat exchange unit equipped with a heat exchanger, A first flow path for distributing refrigerant from the second heat exchange unit to the plurality of first heat exchange units, A second flow path that combines the refrigerant returned from the plurality of first heat exchange units and recovers it in the second heat exchange unit. Equipped with, Each of the first heat exchange units is equipped with a pump that passes the refrigerant supplied from the first channel to the cooling section that cools the object to be cooled by the refrigerant, and sends it to the second channel. Refrigerant circulation system.

2. The first heat exchange unit includes a housing that houses the pump, At least a portion of the forward path of the refrigerant, from the first flow path to the cooling section, is located inside the housing. The return path of the refrigerant, which is sent from the cooling unit to the second flow path, is located outside the housing. The refrigerant circulation system according to claim 1.

3. The heat exchanger is insertable into and removable from the second heat exchange unit. The refrigerant circulation system according to claim 1.

4. The second heat exchange unit comprises a plurality of heat exchangers connected in parallel to the first and second flow paths. The refrigerant circulation system according to claim 1.

5. The system comprises multiple of the aforementioned second heat exchange units. The refrigerant circulation system according to claim 1.

6. A plurality of filters connected in parallel between the first flow path and the pump, The system includes a first valve located between the first flow path and the filter, and a second valve located between the filter and the pump. The refrigerant circulation system according to claim 1.

7. The first heat exchange unit is A distribution channel for distributing refrigerant to a plurality of pumps connected in parallel from the first channel, It comprises an expansion tank connected to the distribution channel and capable of adjusting its internal pressure. The refrigerant circulation system according to claim 1.

8. Each first heat exchange unit is A temperature sensor for detecting the temperature of the refrigerant sent from the cooling unit to the second flow path, The system includes a controller that adjusts the flow rate of the pump according to the temperature of the refrigerant detected by the temperature sensor. The refrigerant circulation system according to claim 1.

9. The system further includes a temperature sensor for detecting the temperature of the refrigerant delivered from the pump to the cooling unit. The controller adjusts the flow rate of the pump according to the temperature of the refrigerant before and after it passes through the cooling section. The refrigerant circulation system according to claim 8.

10. Each of the first heat exchange units is connected to a controller that adjusts the flow rate of the pump in each of the first heat exchange units according to the temperature of the refrigerant after it has passed through the cooling section of each of the first heat exchange units. The refrigerant circulation system according to claim 8.

Images