Cooling system

Abstract

A cooling system according to one aspect of an embodiment of the present invention includes a regulating valve. The regulating valve is provided, in a circulation flow path in which a refrigerant circulates between a cooling plate attached to a device to be cooled and a refrigerant circulation device, in a return path of the refrigerant in which the refrigerant flows from the cooling plate toward the refrigerant circulation device, and adjusts the flow rate of the refrigerant. The regulating valve includes a movable plug and a shape memory alloy member. The movable plug adjusts the flow rate of the refrigerant flowing through the return path. When the temperature of the refrigerant in the return path rises, the shape memory alloy member has a shape for moving the movable plug to a position where the flow rate of the refrigerant is increased, and, when the temperature of the refrigerant returns to the temperature before the rise, the shape memory alloy member has a shape for returning the movable plug to the position before the flow rate of the refrigerant is increased.

Description

Cooling System

[0001] The disclosed embodiments relate to a cooling system. This application claims priority based on Japanese Patent Application No. 2024-232516 filed in Japan on December 27, 2024, and incorporates its content herein by reference.

[0002] There is a cooling system for an electronic unit that includes an adjustment valve for adjusting the flow rate of a refrigerant flowing through the electronic unit, a sensor for detecting the temperature of the refrigerant, and a control unit for adjusting the opening degree of the adjustment valve according to the temperature of the refrigerant detected by the sensor (see, for example, Patent Document 1).

[0003] Japanese Unexamined Patent Application Publication No. 2022-064480

[0004] However, in the prior art cooling system, in order to adjust the flow rate of the refrigerant, a sensor for detecting the temperature of the refrigerant, a control unit for adjusting the opening degree of the adjustment valve according to the temperature of the refrigerant detected by the sensor, and wiring for connecting between the sensor and the control unit are required, so the configuration becomes complicated.

[0005] An aspect of an embodiment aims to provide a cooling system that can autonomously adjust the flow rate of a refrigerant according to the temperature of the refrigerant while having a simple configuration.

[0006] The cooling system according to an aspect of the embodiment includes an adjustment valve. The adjustment valve is provided in the return path of the refrigerant in which the refrigerant circulates between a cooling plate attached to the device to be cooled and a refrigerant circulation device, and is configured to adjust the flow rate of the refrigerant flowing from the cooling plate toward the refrigerant circulation device. The adjustment valve includes a movable plug and a shape memory alloy member. The movable plug adjusts the flow rate of the refrigerant flowing through the return path. When the temperature of the refrigerant in the return path rises, the shape memory alloy member moves the movable plug to a position where the flow rate of the refrigerant is increased, and when the temperature returns to the temperature before the rise of the refrigerant, the shape memory alloy member returns the movable plug to the position before increasing the flow rate of the refrigerant.

[0007] The cooling system according to an aspect of the embodiment can autonomously adjust the flow rate of the refrigerant according to the temperature of the refrigerant while having a simple configuration.

[0008] Figure 1 is an explanatory diagram showing a cooling system according to the first embodiment. Figure 2 is an explanatory diagram showing a control valve according to the first embodiment. Figure 3 is an explanatory diagram showing a control valve according to the first embodiment. Figure 4 is an explanatory diagram showing a control valve according to the first embodiment. Figure 5 is an explanatory diagram showing a control valve according to the first embodiment. Figure 6 is an explanatory diagram showing a control valve according to the first modified example. Figure 7 is an explanatory diagram showing a control valve according to the first modified example. Figure 8 is an explanatory diagram showing a control valve according to the first modified example. Figure 9 is an explanatory diagram showing a control valve according to the first modified example. Figure 10 is an explanatory diagram showing a control valve according to the second modified example. Figure 11 is an explanatory diagram showing a control valve according to the second modified example. Figure 12 is an explanatory diagram showing a cooling system according to the second embodiment. Figure 13 is an explanatory diagram showing a cooling system according to the third embodiment. Figure 14 is an explanatory diagram showing a cooling system according to the fourth embodiment.

[0009] The embodiments for implementing the cooling system according to this disclosure (hereinafter referred to as "Embodiments") will be described in detail below with reference to the drawings. However, this disclosure is not limited by these embodiments. Furthermore, the embodiments can be combined as appropriate. In the following embodiments, components that perform the same function are denoted by the same reference numerals, and redundant explanations will be omitted.

[0010] Furthermore, in the embodiments described below, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not require strict adherence to "constant," "orthogonal," "perpendicular," or "parallel" conditions. In other words, each of the above expressions allows for deviations such as manufacturing accuracy or installation accuracy.

[0011] Figure 1 is an explanatory diagram showing a cooling system 2 according to the first embodiment. The cooling system 2 cools a plurality of devices 3 to be cooled. The devices 3 to be cooled are, for example, electronic equipment installed in a data center. Electronic equipment installed in a data center are, for example, heat-generating computing devices such as CPUs (Central Processing Units).

[0012] The cooling system 2 includes a cooling plate 4, a refrigerant circulation device 10, and a cooling tower 7. The cooling plate 4 is attached to the device to be cooled 3. The refrigerant circulation device 10 comprises a pump unit 11 and a heat exchanger 12.

[0013] The refrigerant circulation device 10 is connected to the cooling tower 7 by a circulation channel through which the primary refrigerant circulates. The refrigerant circulation device 10 is also connected to the cooling plate 4 by a circulation channel 5 through which the secondary refrigerant circulates.

[0014] Figure 1 shows the circulation path for the primary refrigerant with a thick dotted arrow, and the circulation path 5 for the secondary refrigerant with a thick solid arrow. The circulation path 5 includes a forward path 52 for the refrigerant that sends the secondary refrigerant from the refrigerant circulation device 10 to the cooling plate 4, and a return path 51 for the refrigerant that returns the secondary refrigerant from the cooling plate 4 to the refrigerant circulation device 10.

[0015] The forward path 52 branches off from a single refrigerant supply channel 53, to which secondary refrigerant is supplied from the refrigerant circulation device 10, into at least two (three in this case) refrigerant forward paths 54, each branching off to a plurality (three in this case) of cooling plates 4 with different destinations. The return path 51 converges from a plurality (three in this case) of refrigerant return paths 55, to which secondary refrigerant returns from the plurality (three in this case) of cooling plates 4, into a single refrigerant return channel 56, which then connects to the refrigerant circulation device 10.

[0016] The refrigerant circulation device 10 sends secondary refrigerant to the forward path 52 by the pump unit 11. The secondary refrigerant sent to the forward path 52 absorbs heat from the cooling device 3 as it passes through the cooling plate 4. The heat-absorbing secondary refrigerant flows into the heat exchanger 12 of the refrigerant circulation device 10 through the return path 51.

[0017] Furthermore, the primary refrigerant cooled by the cooling tower 7 is continuously supplied to the heat exchanger 12. As the primary refrigerant passes through the heat exchanger 12, it absorbs heat from the secondary refrigerant, cooling it, and is then returned to the cooling tower 7. The cooled secondary refrigerant is then sent back to the outbound path 52 from the heat exchanger 12. In this way, the cooling system 2 cools multiple devices 3 to be cooled.

[0018] Here, the multiple cooling devices 3 each generate different amounts of heat due to differences in their operating state, type, and function. Therefore, the cooling system 2 needs to supply more secondary refrigerant to the cooling plates 4 attached to the cooling devices 3 that generate a large amount of heat than to the cooling plates 4 attached to the cooling devices 3 that generate a small amount of heat, in order to increase the cooling efficiency.

[0019] Furthermore, the cooling system 2 does not need to supply as much secondary refrigerant to a cooling plate 4 attached to a cooling target device 3 with a small heat generation as it does to a cooling plate 4 attached to a cooling target device 3 with a large heat generation.

[0020] Therefore, the cooling system 2 is equipped with a control valve 6 that can adjust the amount of secondary refrigerant supplied to each cooling plate 4 according to the temperature of the secondary refrigerant. The control valve 6 is installed in the return path 51 of the circulation flow path 5, through which the secondary refrigerant flows from the cooling plate 4 to the refrigerant circulation device 10, and adjusts the flow rate of the secondary refrigerant. Specifically, each control valve 6 is installed in each refrigerant return path 55 located directly downstream of each cooling plate 4 in the secondary refrigerant return path 51.

[0021] Each control valve 6 is configured to autonomously increase the flow rate of the secondary refrigerant when the temperature of the secondary refrigerant flowing in from each refrigerant return path 55 rises, and to autonomously return the flow rate to the level before it was increased when the temperature of the secondary refrigerant returns to the temperature before it rose.

[0022] As a result, the cooling system 2 can selectively and automatically increase the flow rate of secondary refrigerant supplied to cooling target devices 3 that require an increased flow rate of secondary refrigerant among the multiple cooling target devices 3.

[0023] Figures 2 to 5 are explanatory diagrams showing the control valve 6 according to the first embodiment. Figure 2 shows a partial cross-sectional structure inside the control valve 6 before the temperature of the secondary refrigerant rises. Figure 3 shows a partial cross-sectional structure inside the control valve 6 when the temperature of the secondary refrigerant rises. In Figures 2 and 3, the flow of the secondary refrigerant is indicated by white arrows. Figure 4 shows a side view of the movable plug 62 of the control valve 6. Figure 5 shows a front view of the movable plug 62.

[0024] As shown in Figures 2 and 3, the control valve 6 comprises a housing 61, a movable plug 62, a shape memory alloy member 63, and an elastic member 64. The housing 61 has an elongated cylindrical space inside. The housing 61 also has an inlet 65 at one end face in the longitudinal direction of the internal space through which the secondary refrigerant flows in, and an outlet 66 at the other end face in the longitudinal direction of the internal space through which the secondary refrigerant flows out. The inlet 65 has a shape that widens from the outside to the inside of the housing 61.

[0025] As shown in Figures 4 and 5, the movable plug 62 includes a cylindrical plug portion 68 and a conical flow rate adjustment portion 69 provided on one end face of the plug portion 68. The plug portion 68 has a plurality (in this case, four) of through holes 67 through which the secondary refrigerant passes.

[0026] The movable plug 62 is located within the internal space of the housing 61 with the tip of its conical flow rate adjustment section 69 facing the inlet 65. As shown in Figures 2 and 3, the movable plug 62 is slidable within the internal space of the housing 61 in the longitudinal direction of the internal space.

[0027] As shown in Figure 2, when the movable valve 62 approaches the inlet 65, the flow rate adjustment unit 69 reduces the opening of the inlet 65, thereby decreasing the flow rate of the secondary refrigerant. Conversely, as shown in Figure 3, when the movable valve 62 moves away from the inlet 65, the flow rate adjustment unit 69 increases the opening of the inlet 65, thereby increasing the flow rate of the secondary refrigerant. In this way, the movable valve 62 adjusts the flow rate of the secondary refrigerant flowing through the refrigerant return path 55 in the return path 51 by changing its position within the internal space of the housing 61.

[0028] The shape memory alloy member 63 is a compression coil spring. The shape memory alloy member 63 is located on the secondary refrigerant inlet 65 side of the movable plug 62 in the internal space of the housing 61. The elastic member 64 is a compression coil spring. The elastic member 64 is located on the secondary refrigerant outlet 66 side of the movable plug 62 in the internal space of the housing 61. The elastic member 64 biases the movable plug 62 in the direction from the outlet 66 toward the inlet 65.

[0029] When the temperature of the secondary refrigerant rises, the shape memory alloy member 63 becomes an austenite phase, causing the compression coil spring to stretch and biasing the movable plug 62 from the inlet 65 towards the outlet 66. When the temperature of the secondary refrigerant returns to its temperature before the rise, the shape memory alloy member 63 becomes a martensite phase.

[0030] Furthermore, when the shape memory alloy member 63 is in the austenite phase, the biasing force that counteracts the biasing force of the elastic member 64 is greater than the biasing force of the elastic member 64, and when it is in the martensite phase, the biasing force that counteracts the biasing force of the elastic member 64 is smaller than the biasing force of the elastic member 64.

[0031] Therefore, when the temperature of the secondary refrigerant flowing through the refrigerant return path 55 in the return path 51 rises, the shape memory alloy member 63 moves the movable plug 62 to a position that increases the flow rate of the secondary refrigerant, as shown in Figure 3. Then, when the temperature of the secondary refrigerant returns to its temperature before the rise due to the increased flow rate of the secondary refrigerant, the shape memory alloy member 63 returns the movable plug 62 to the position it was in before the increase in the flow rate of the secondary refrigerant, as shown in Figure 2.

[0032] Thus, in the cooling system 2, when the temperature of the secondary refrigerant flowing inside the control valve 6 rises, the control valve 6 autonomously increases the flow rate of the secondary refrigerant, and when the temperature of the secondary refrigerant returns to the temperature before it rose, the control valve 6 autonomously returns to the flow rate before it was increased.

[0033] Therefore, the cooling system 2 can adjust the flow rate of the secondary refrigerant according to its temperature, even without a sensor to detect the temperature of the secondary refrigerant, a control unit to adjust the flow rate of the secondary refrigerant according to the sensor's detection result, or wiring connecting the sensor and the control unit. In other words, the cooling system 2 allows for automatic adjustment of the flow rate of the secondary refrigerant according to its temperature, despite its simple configuration.

[0034] Furthermore, the cooling system 2 automatically adjusts the opening of the control valve 6 by utilizing the fact that the shape memory alloy member 63 becomes an austenite phase when the temperature of the secondary refrigerant rises, and becomes a martensite phase when the temperature of the secondary refrigerant returns to the temperature before the rise. Therefore, according to the cooling system 2, by utilizing the transformation of the shape memory alloy member 63 from soft to hard, the flow rate of the secondary refrigerant can be automatically increased when the temperature of the secondary refrigerant rises.

[0035] Furthermore, as described above, when the shape memory alloy member 63 becomes the austenite phase, the biasing force that counteracts the biasing force of the elastic member 64 is greater than the biasing force of the elastic member 64. And when the shape memory alloy member 63 becomes the martensite phase, the biasing force that counteracts the biasing force of the elastic member 64 is smaller than the biasing force of the elastic member 64.

[0036] As a result, when the temperature of the secondary refrigerant rises, the cooling system 2 can increase the opening degree of the movable plug 62 due to the biasing force of the shape memory alloy member 63, and when the temperature of the secondary refrigerant returns to the temperature before it rose, the opening degree of the movable plug 62 can be decreased due to the biasing force of the elastic member 64.

[0037] Furthermore, the cooling system 2 can incorporate a control valve 6 that automatically adjusts the flow rate of the secondary refrigerant according to its temperature, using an elastic member 64 with a simple spring structure and a shape memory alloy member 63.

[0038] Furthermore, the shape memory alloy member 63 has a transformation temperature in the range of 5°C to 80°C. This allows the cooling system 2 to adjust the flow rate of the secondary refrigerant within the temperature range expected in the operating environment of typical electronic devices.

[0039] Furthermore, it is desirable that the shape memory alloy member 63 has a small temperature difference between the temperature at which it changes from the martensite phase to the austenite phase and the temperature at which it changes from the austenite phase to the martensite phase. This allows the shape memory alloy member 63 to follow the temperature changes of the secondary refrigerant passing through the control valve 6 and adjust the flow rate of the secondary refrigerant with high precision.

[0040] Further, the shape memory alloy member 63 contains nickel and titanium. Therefore, according to the cooling system 2, the shape memory alloy member 63 of the regulating valve 6 can be formed of nickel and titanium which are common as materials for shape memory alloys.

[0041] Further, the regulating valve 6 of the cooling system 2 is provided in the return path 51 of the secondary refrigerant that connects the cooling plate 4 attached to the electronic equipment in the data center and the refrigerant circulation device 10. Therefore, according to the cooling system 2, while having a simple configuration, for each electronic device in the data center, the flow rate of the secondary refrigerant for cooling each electronic device can be automatically and individually adjusted according to the temperature of the secondary refrigerant.

[0042] Note that the configuration of the regulating valve 6 shown in FIGS. 2 to 5 is an example, and various modifications are possible. FIGS. 6 to 9 are explanatory views showing a regulating valve 8 according to a first modification. FIGS. 10 and 12 are explanatory views showing a regulating valve 9 according to a second modification.

[0043] FIG. 6 shows a partial cross-sectional structure inside the regulating valve 8 before the temperature of the secondary refrigerant rises. FIG. 7 shows a partial cross-sectional structure inside the regulating valve 8 when the temperature of the secondary refrigerant has risen. In FIGS. 6 and 6, the flow of the secondary refrigerant is indicated by a white arrow. Further, FIG. 8 shows a side surface of the movable plug 82 of the regulating valve 8. FIG. 9 shows a front surface of the movable plug 82.

[0044] Further, FIG. 10 shows a partial cross-sectional structure inside the regulating valve 9 before the temperature of the secondary refrigerant rises. FIG. 11 shows a partial cross-sectional structure inside the regulating valve 9 when the temperature of the secondary refrigerant has risen. In FIGS. 10 and 11, the flow of the secondary refrigerant is indicated by a white arrow.

[0045] As shown in FIGS. 8 and 7, the regulating valve 8 according to the first modification includes a housing body 81, a movable plug 82, a shape memory alloy member 83, and an elastic member 84. The housing body 81 has an elongated cylindrical space inside. Further, the housing body 81 is provided with an inlet 85 through which the secondary refrigerant flows in at one end surface in the short side direction of the internal space, and an outlet 86 through which the secondary refrigerant flows out at the other end surface in the short side direction of the internal space.

[0046] As shown in FIGS. 8 and 9, the movable plug 82 includes a cylindrical plug portion 88 and a support rod 89 provided on one end face of the plug portion 88. The plug portion 88 has a through hole 87 through which the secondary refrigerant passes. The movable plug 82 is located within the internal space of the housing 81. As shown in FIGS. 6 and 7, the movable plug 82 is slidable within the internal space of the housing 81 in the longitudinal direction of the internal space.

[0047] As shown in FIG. 6, the movable plug 82 reduces the flow rate of the secondary refrigerant by reducing the opening degree of the inlet 85 when the plug portion 88 is located between the inlet 85 and the outlet 86. Also, as shown in FIG. 7, the movable plug 82 increases the flow rate of the secondary refrigerant by increasing the opening degree of the inlet 85 when moving from between the inlet 85 and the outlet 86 such that the plug portion 88 moves away. Thus, the movable plug 82 adjusts the flow rate of the secondary refrigerant flowing through the refrigerant return path 55 in the return path 51 by changing its position within the internal space of the housing 81.

[0048] The shape memory alloy member 83 is a compression coil spring. The elastic member 84 is a compression coil spring. The shape memory alloy member 83 and the elastic member 84 are located on both sides of the plug portion 88 of the movable plug 82 in the longitudinal direction of the internal space of the housing 81. The elastic member 84 biases the movable plug 82 in the direction toward the shape memory alloy member 83.

[0049] When the temperature of the secondary refrigerant rises, the shape memory alloy member 83 becomes an austenite phase and the compression coil spring is in an extended state, biasing the movable plug 82 in the direction toward the elastic member 84. Also, when the temperature of the secondary refrigerant returns to the temperature before the rise, the shape memory alloy member 83 becomes a martensite phase.

[0050] Further, the shape memory alloy member 83 has a biasing force that opposes the biasing force of the elastic member 84 and is greater than the biasing force of the elastic member 84 when it becomes an austenite phase, and a biasing force that opposes the biasing force of the elastic member 84 and is smaller than the biasing force of the elastic member 84 when it becomes a martensite phase.

[0051] Therefore, when the temperature of the secondary refrigerant flowing through the refrigerant return path 55 in the return path 51 rises, the shape memory alloy member 83 moves the movable plug 82 to a position that increases the flow rate of the secondary refrigerant, as shown in Figure 7. Then, when the temperature of the secondary refrigerant returns to its temperature before the rise due to the increased flow rate of the secondary refrigerant, the shape memory alloy member 83 returns the movable plug 82 to the position before the increase in the flow rate of the secondary refrigerant, as shown in Figure 6.

[0052] Thus, in the cooling system 2, when the temperature of the secondary refrigerant flowing inside the control valve 8 rises, the control valve 8 autonomously increases the flow rate of the secondary refrigerant, and when the temperature of the secondary refrigerant returns to the temperature before it rose, the control valve 8 autonomously returns to the flow rate before it was increased.

[0053] With this control valve 8, when the temperature of the secondary refrigerant rises, the flow rate of the secondary refrigerant is autonomously increased, and when the temperature of the secondary refrigerant returns to the temperature before it rose, the flow rate of the secondary refrigerant is returned to the flow rate before it was increased.

[0054] Furthermore, as shown in Figures 10 and 11, the shape memory alloy member 93 of the second modified control valve 9 is different from the shape memory alloy member 83 of the first modified control valve 8. The housing 91, movable plug 92, and elastic member 94 of the second modified control valve 9 are the same as the housing 81, movable plug 82, and elastic member 84 of the first modified control valve 8.

[0055] Therefore, the housing 91 according to the second modified example is provided with a secondary refrigerant inlet 95 and a secondary refrigerant outlet 96 in the same positions as the housing 81 according to the first modified example. Furthermore, the shapes of the plug portion, through hole 97, and support rod 99 of the movable plug 92 according to the second modified example are the same as the shapes of the plug portion 88, through hole 87, and support rod 89 of the movable plug 82 according to the first modified example.

[0056] The shape memory alloy member 93 according to the second modification is positioned in the same location as the shape memory alloy member 83 according to the first modification. The shape memory alloy member 93 is a rod formed of shape memory alloy. One end of the shape memory alloy member 93 is in contact with the end face of the movable plug 92 on the side where the support rod 99 is provided, and the other end is in contact with the inner surface of the housing 91 facing the end face of the movable plug 92 on the side where the support rod 99 is provided.

[0057] When the shape memory alloy member 93 enters the austenite phase, it becomes a rod-like shape and biases the movable plug 92 toward the elastic member 84. Furthermore, when the shape memory alloy member 83 returns to the temperature it was at before the secondary refrigerant temperature rose, it enters the martensite phase.

[0058] Furthermore, when the shape memory alloy member 93 is in the austenite phase, the biasing force that counteracts the biasing force of the elastic member 94 is greater than the biasing force of the elastic member 94, and when it is in the martensite phase, the biasing force that counteracts the biasing force of the elastic member 94 is smaller than the biasing force of the elastic member 94.

[0059] Therefore, when the temperature of the secondary refrigerant flowing through the refrigerant return path 55 in the return path 51 rises, the shape memory alloy member 93 moves the movable plug 92 to a position that increases the flow rate of the secondary refrigerant, as shown in Figure 11. Then, when the temperature of the secondary refrigerant returns to its temperature before the rise due to the increased flow rate of the secondary refrigerant, the shape memory alloy member 93 returns the movable plug 92 to the position before the increase in the flow rate of the secondary refrigerant, as shown in Figure 10.

[0060] Thus, in the cooling system 2, when the temperature of the secondary refrigerant flowing inside the control valve 9 rises, the control valve 9 autonomously increases the flow rate of the secondary refrigerant, and when the temperature of the secondary refrigerant returns to the temperature before it rose, the control valve 9 autonomously returns to the flow rate before it was increased.

[0061] With this control valve 9, when the temperature of the secondary refrigerant rises, the flow rate of the secondary refrigerant is autonomously increased, and when the temperature of the secondary refrigerant returns to the temperature before it rose, the flow rate of the secondary refrigerant is returned to the flow rate before it was increased.

[0062] Up to this point, we have described the cooling system 2 for cooling electronic equipment in a data center, but the cooling system according to this embodiment can also cool automotive electronic components. The following describes a cooling system for cooling automotive electronic components.

[0063] Figure 12 is an explanatory diagram showing the cooling system 21 according to the second embodiment. Figure 13 is an explanatory diagram showing the cooling system 22 according to the third embodiment. Figure 14 is an explanatory diagram showing the cooling system 23 according to the third embodiment. Note that the cooling plate 4 and cooling tower 7 attached to the in-vehicle electronic equipment are not shown in Figures 12 to 14.

[0064] As shown in Figure 12, the cooling system 21 according to the second embodiment includes a forward path 52 that supplies secondary refrigerant from the refrigerant circulation device 10 to the ECU (Electronic Control Unit) 31, the OBC (On Board Charger) / DC / DC (DCDC converter) 32, and the battery 33. The cooling system 21 also includes a return path 51 that returns secondary refrigerant from the OBC / DC / DC converter 32 and the battery 33 to the refrigerant circulation device 10.

[0065] The secondary refrigerant is supplied from the refrigerant circulation device 10, via a cooling plate attached to the ECU 31, to the cooling plate attached to the OBC / DC / DC 32 and the cooling plate attached to the battery 33. Subsequently, the secondary refrigerant returns to the refrigerant circulation device 10 from the cooling plate attached to the OBC / DC / DC 32 and the cooling plate attached to the battery 33.

[0066] In the cooling system 21, the control valve 6 is provided in the refrigerant return path 55 of the secondary refrigerant return path 51, which connects the cooling plate attached to the OBC / DC / DC 32 and the cooling plate attached to the battery 33 with the refrigerant circulation device 10.

[0067] According to the cooling system 21, the flow rate of the secondary refrigerant supplied to the cooling plate attached to the OBC / DC / DC 32 and the cooling plate attached to the battery 33 can be automatically adjusted by the adjustment valve 6 in response to temperature changes in the OBC / DC / DC 32 and the battery 33.

[0068] Furthermore, as shown in Figure 13, the cooling system 22 according to the third embodiment includes a forward path 52 that supplies secondary refrigerant from the refrigerant circulation device 10 to the OBC DC / DC 32 and the two inverter module capacitors 34. The cooling system 22 includes a return path 51 that returns secondary refrigerant from the OBC DC / DC 32, the two inverter module capacitors 34, and the drive motor gear 35 to the refrigerant circulation device 10.

[0069] The secondary refrigerant is supplied from the refrigerant circulation device 10 to the cooling plate attached to the drive motor gear 35, via the cooling plates attached to the OBC DC / DC 32 and the two inverter module capacitors 34. The secondary refrigerant then returns from the cooling plate attached to the drive motor gear 35 to the refrigerant circulation device 10.

[0070] In the cooling system 22, the control valve 6 is provided in the refrigerant return path 55 connected to the cooling plate attached to the OBC DC / DC 32 and the cooling plate attached to the two inverter module capacitors 34.

[0071] According to the cooling system 22, the flow rate of the secondary refrigerant supplied to the cooling plate attached to the OBC / DC / DC 32 can be automatically adjusted by the control valve 6 in response to temperature changes in the OBC / DC / DC 32. Furthermore, according to the cooling system 22, the flow rate of the secondary refrigerant supplied to the cooling plate attached to the two inverter module condensers 34 can be automatically adjusted by the control valve 6 in response to temperature changes in the two inverter module condensers 34.

[0072] As shown in Figure 14, the cooling system 23 according to the fourth embodiment includes a forward path 52 that supplies secondary refrigerant from the refrigerant circulation device 10 to the OBC DC / DC 32, inverter module capacitor 34, and ECU unit ADAS (Advanced Driver Assistance System) 36. The cooling system 23 also includes a return path 51 that returns secondary refrigerant from the OBC DC / DC 32, inverter module capacitor 34, ECU unit ADAS 36, and drive motor gear 35 to the refrigerant circulation device 10.

[0073] The secondary refrigerant is supplied from the refrigerant circulation device 10 to the cooling plate attached to the drive motor gear 35, via the cooling plate attached to the OBC DC / DC 32 and the cooling plate attached to the inverter module capacitor 34.

[0074] Furthermore, the secondary refrigerant is supplied from the refrigerant circulation device 10 to a cooling plate attached to the ECU unit ADAS 36. Subsequently, the secondary refrigerant returns to the refrigerant circulation device 10 from the cooling plate attached to the drive motor gear 35 and the cooling plate attached to the ECU unit ADAS 36.

[0075] In the cooling system 23, the control valve 6 is provided in the refrigerant return path 55 connected to the cooling plate attached to the OBC DC / DC 32. The control valve 6 is also provided in the refrigerant return path 55 connected to the cooling plate attached to the inverter module condenser 34. Furthermore, the control valve 6 is provided in the refrigerant return path 55 connected to the cooling plate attached to the ECU unit ADAS 36.

[0076] According to the cooling system 23, the flow rate of the secondary refrigerant supplied to the cooling plate attached to the OBC / DC / DC 32 can be automatically adjusted by the control valve 6 in response to temperature changes in the OBC / DC / DC 32.

[0077] Furthermore, according to the cooling system 23, the flow rate of the secondary refrigerant supplied to the cooling plate attached to the inverter module condenser 34 can be automatically adjusted by the control valve 6 in response to temperature changes in the inverter module condenser 34.

[0078] Furthermore, the cooling system 23 allows the flow rate of the secondary refrigerant supplied to the cooling plate attached to the ECU unit and ADAS 36 to be automatically adjusted by the adjustment valve 6 in response to temperature changes in the ECU unit and ADAS 36.

[0079] Thus, in the cooling systems 21, 22, and 23, the control valve 6 is provided in the return path 51 of the secondary refrigerant that connects the cooling plate attached to the in-vehicle electronic component to the refrigerant circulation device 10. Therefore, with the cooling systems 21, 22, and 23, despite their simple configuration, the flow rate of the secondary refrigerant that cools each in-vehicle electronic component can be autonomously and individually adjusted according to the temperature of the secondary refrigerant.

[0080] Furthermore, this technology can be configured as follows: (1) A cooling system including a control valve provided in the return path of the refrigerant flowing from the cooling plate toward the refrigerant circulation device, in a circulation path through which the refrigerant circulates between a cooling plate attached to a device to be cooled and a refrigerant circulation device, wherein the control valve includes a movable plug that adjusts the flow rate of the refrigerant flowing toward the return path, and a shape memory alloy member that, when the temperature of the refrigerant in the return path rises, moves the movable plug to a position that increases the flow rate of the refrigerant, and when the temperature of the refrigerant returns to the temperature before it rose, returns the movable plug to the position before the increase in the flow rate of the refrigerant. (2) The cooling system according to (1), wherein the circulation path includes a refrigerant supply path from which refrigerant is supplied from the refrigerant circulation device, which branches off into at least two or more refrigerant forward paths, each branching off to a plurality of cooling plates with different destinations, and a refrigerant return path from which refrigerant returns from a plurality of cooling plates, which converges into a single refrigerant return path and converges to the refrigerant circulation device, and the control valve is provided in the plurality of refrigerant return paths. (3) The cooling system according to (1) or (2), wherein the shape memory alloy member becomes an austenite phase when the temperature of the refrigerant rises and becomes a martensite phase when the temperature of the refrigerant returns to the temperature before the rise. (4) The cooling system according to (3), wherein the regulating valve includes an elastic member that biases the movable plug toward the position before increasing the flow rate of the refrigerant, and the shape memory alloy member has a biasing force that is greater than the biasing force of the elastic member when it is in the austenite phase, and a biasing force that is less than the biasing force of the elastic member when it is in the martensite phase. (5) The cooling system according to (4), wherein the shape memory alloy member and the elastic member are springs. (6) The cooling system according to any one of (1) to (5), wherein the shape memory alloy member has a transformation point in the range of 5°C to 80°C. (7) The cooling system according to any one of (1) to (6), wherein the shape memory alloy member contains nickel and titanium.(8) The cooling system according to any one of (1) to (7), wherein the control valve is provided in the return path of the refrigerant connecting the cooling plate attached to the electronic equipment in the data center and the refrigerant circulation device. (9) The cooling system according to any one of (1) to (7), wherein the control valve is provided in the return path of the refrigerant connecting the cooling plate attached to the electronic equipment in the vehicle and the refrigerant circulation device.

[0081] 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.

[0082] 2, 21, 22, 23 Cooling system 3 Cooling target device 4 Cooling plate 5 Circulation path 6 Control valve 7 Cooling tower 8 Control valve 9 Control valve 10 Refrigerant circulation device 11 Pump unit 12 Heat exchanger 33 Battery 34 Inverter module / capacitor 35 Drive motor / gear 51 Return path 52 Forward path 53 Refrigerant supply path 54 Refrigerant forward path 55 Refrigerant return path 56 Refrigerant return path 61, 81, 91 Housing 62, 82, 92 Movable plug 63, 83, 93 Shape memory alloy member 64, 84, 94 Elastic member 65, 85, 95 Inlet 66, 86, 96 Outlet 67, 87, 97 Through hole 68, 88 Plug part 69 Flow rate adjustment part 89, 99 Support rod

Claims

1. A cooling system comprising a cooling valve provided in the return path of a refrigerant flowing from a cooling plate toward a refrigerant circulation device, in a circulation path through which a refrigerant circulates between a cooling plate attached to a device to be cooled, wherein the refrigerant flow is adjusted by adjusting the flow rate of the refrigerant, the adjustment valve comprising: a movable plug that adjusts the flow rate of the refrigerant flowing toward the return path; and a shape memory alloy member that, when the temperature of the refrigerant in the return path rises, moves the movable plug to a position that increases the flow rate of the refrigerant, and when the temperature of the refrigerant returns to the temperature before it rose, returns the movable plug to the position before the increase in the flow rate of the refrigerant.

2. The cooling system according to claim 1, wherein the circulation path includes a refrigerant supply path from which refrigerant is supplied from the refrigerant circulation device, which branches off into at least two or more refrigerant forward paths, each branching off to a plurality of cooling plates with different destinations, and a plurality of refrigerant return paths from which refrigerant returns from the plurality of cooling plates, which converge into a single refrigerant return path and converge to the refrigerant circulation device, and the control valve is provided in the plurality of refrigerant return paths.

3. The cooling system according to claim 1 or 2, wherein the shape memory alloy member becomes an austenite phase when the temperature of the refrigerant rises, and becomes a martensite phase when the temperature of the refrigerant returns to the temperature before the rise.

4. The cooling system according to claim 3, wherein the control valve includes an elastic member that biases the movable plug toward the position before increasing the flow rate of the refrigerant, and the shape memory alloy member has a biasing force that is greater than the biasing force of the elastic member when it is in the austenite phase, and a biasing force that is less than the biasing force of the elastic member when it is in the martensite phase.

5. The cooling system according to claim 4, wherein the shape memory alloy member and the elastic member are springs.

6. The cooling system according to claim 1 or 2, wherein the shape memory alloy member has a transformation point in the range of 5°C to 80°C.

7. The cooling system according to claim 1 or claim 2, wherein the shape memory alloy member comprises nickel and titanium.

8. The cooling system according to claim 1 or 2, wherein the control valve is provided in the return path of the refrigerant connecting the cooling plate, which is attached to electronic equipment in a data center, and the refrigerant circulation device.

9. The cooling system according to claim 1 or 2, wherein the control valve is provided in the return path of the refrigerant connecting the cooling plate, which is attached to an in-vehicle electronic component, and the refrigerant circulation device.

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