An energy storage system and its inlet and outlet liquid control method

Abstract

The present application relates to the field of energy storage technology and discloses an energy storage system and a method for controlling liquid inlet and outlet thereof. The energy storage system includes a coolant circuit, a refrigerant circuit, a heat exchange device, a liquid cooling plate, and a battery pack. The refrigerant circuit includes a main refrigerant circuit and a branch refrigerant circuit. The heat exchange device includes a coolant pipeline connected to the coolant circuit and a refrigerant pipeline connected to the main refrigerant circuit. The liquid cooling plate includes a coolant flow channel connected to the coolant circuit and a refrigerant flow channel connected to the branch refrigerant circuit. The battery pack is bonded to the liquid cooling plate. A temperature control switch is provided at the liquid inlet of the refrigerant flow channel. When the temperature of the battery pack meets a first preset condition, the temperature control switch is closed, and the liquid cooling plate cools the battery pack with the coolant. When the temperature of the battery pack meets a second preset condition, the temperature control switch is opened, and the liquid cooling plate cools the battery pack with the coolant and the refrigerant. This allows the refrigerant to flow into the liquid cooling plate under specific operating conditions, thereby improving the safety of the battery pack and reducing the operating cost of the energy storage system.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to an energy storage system and a method for controlling liquid inlet and outlet thereof. Background Art

[0002] Currently, energy storage systems primarily utilize air cooling, liquid cooling, or a combination of both to maintain internal temperatures within a safe range, thereby ensuring safety during operation. When liquid cooling is employed, a liquid cooling plate can be bonded to the battery pack to cool the system. This allows the coolant and / or refrigerant flowing through the plate to remove most of the heat generated by the battery pack during operation through heat exchange, thereby ensuring operational stability and extending its lifespan.

[0003] In the prior art, if only one of the coolant and refrigerant flows through the liquid cooling plate, the overall cooling effect of the liquid cooling plate will be reduced. However, if both the coolant and refrigerant flow through the liquid cooling plate at the same time, the overall energy consumption of the energy storage device will increase. Summary of the Invention

[0004] In view of this, the present application provides an energy storage system and a method for controlling liquid inlet and outlet thereof to solve the technical problems in the prior art in that the refrigeration effect is reduced when coolant or refrigerant circulates alone, and the energy consumption is increased when coolant and refrigerant circulate simultaneously.

[0005] The present application provides an energy storage system, which includes a coolant circuit, a refrigerant circuit, a heat exchange device, a liquid cooling plate, and a battery pack. The refrigerant circuit includes a main refrigerant circuit and a branch refrigerant circuit; the heat exchange device includes a coolant pipeline and a refrigerant pipeline, the heat exchange device is connected to the coolant circuit via the coolant pipeline, and the heat exchange device is connected to the main refrigerant circuit via the refrigerant pipeline; the liquid cooling plate includes a coolant flow channel and a refrigerant flow channel, the liquid cooling plate is connected to the coolant circuit via the coolant flow channel, and the liquid cooling plate is connected to the refrigerant branch refrigerant channel; the battery pack is bonded to the liquid cooling plate.

[0006] Among them, the first temperature of the battery pack at the coolant flow channel inlet is T1, the second temperature of the battery pack at the coolant flow channel outlet is T2, and the coolant flow channel inlet is also provided with a temperature control switch.

[0007] When T1 and T2 meet T1-T2<2℃, or T2 meets T2<25℃, the temperature control switch is in the off state, and the liquid cooling plate cools the battery pack through the coolant;

[0008] When T1 and T2 meet T1-T2≥2℃, or T2 meets T2≥25℃, the temperature control switch is in the open state, and the liquid cooling plate cools the battery pack through coolant and refrigerant.

[0009] The beneficial effect of the present application is that the coolant circuit and the refrigerant circuit perform heat exchange through the heat exchange device, thereby ensuring that the coolant flowing into the liquid cold plate has a lower temperature, so that it can absorb more heat, thereby improving the cooling effect of the liquid cold plate on the battery pack; it can also enable the liquid cold plate to cool the battery pack alone through the coolant, or to cool the battery pack together through the coolant and refrigerant, to ensure that the temperature of the battery pack is always maintained within a safe temperature range, thereby improving the stability and reliability of the energy storage system during operation.

[0010] At the same time, the refrigerant can flow into the liquid cold plate under specific working conditions, so that part of the refrigerant can continue to exchange heat with the high-temperature coolant, and the other part of the refrigerant can absorb the heat of the battery pack together with the coolant, thereby enabling the coolant to flow continuously in the liquid cold plate. The intermittent flow of the refrigerant in the liquid cold plate is beneficial to improving the safety of the battery pack in a high-power state or high-temperature environment, reducing the difficulty of controlling the phase, pressure and temperature of the refrigerant in the liquid cold plate, and reducing the operating cost and maintenance cost of the energy storage system.

[0011] In one possible embodiment, the temperature control switch includes a valve and a driving member. The valve is installed in the refrigerant flow channel and is rotatably connected to the refrigerant flow channel. The driving member is fixedly connected to the valve and is used to drive the valve to rotate relative to the refrigerant flow channel to open or close the liquid inlet of the refrigerant flow channel.

[0012] The valve also includes a first door plate and a second door plate connected to each other. The first door plate has a through hole and is located on a side of the second door plate away from the refrigerant flow channel inlet, and has a first angle with the second door plate.

[0013] In a possible embodiment, the driving member is a shape memory alloy. Along the thickness direction of the liquid cooling plate, one end of the shape memory alloy is connected to the first door panel, and the other end of the shape memory alloy is connected to the top wall of the refrigerant flow channel.

[0014] When T1 and T2 satisfy T1-T2≥2°C, or T2 satisfies T2≥25°C, the shape memory alloy can shrink and drive the first door panel to move along the first direction x to open the liquid inlet of the refrigerant flow channel. The first direction x is opposite to the flow direction of the refrigerant.

[0015] When T1 and T2 satisfy T1-T2<2℃, or T2 satisfies T2<25℃, the shape memory alloy can return to its initial state and drive the first door panel to move along the second direction y to close the liquid inlet of the refrigerant flow channel. The second direction y is the same as the flow direction of the refrigerant.

[0016] In a possible embodiment, the refrigerant flow channel is also provided with a groove, and the temperature control switch also includes a guide column and an elastic member, the guide column is arranged on the bottom wall of the groove, the elastic member is sleeved on the outer wall of the guide column, and one end of the elastic member is connected to the bottom wall of the groove, and the other end of the elastic member is connected to the first door panel.

[0017] In a possible implementation, the energy storage system further includes a drain valve installed on the bottom wall of the groove.

[0018] When T1 and T2 satisfy T1-T2<2°C, or T2 satisfies T2<25°C, the drain valve is in an open state to discharge the refrigerant in the groove.

[0019] When T1 and T2 satisfy T1-T2≥2°C, or T2 satisfies T2≥25°C, the drain valve is in a closed state to prevent the refrigerant in the groove from being discharged.

[0020] In one possible embodiment, the energy storage system further includes a control system and a detection device. The control system is electrically or signal-connected to the detection device, and is also electrically or signal-connected to the drain valve and / or the drive member. The detection device is installed on the side of the liquid cooling plate facing the battery pack and is used to detect the temperature of the battery pack. The control system is used to control the start or stop of the drive member and / or control the opening or closing of the drain valve according to the detection results of the detection device.

[0021] In a possible embodiment, the liquid cooling plate includes at least two cooling liquid flow channels and at least one refrigerant flow channel. The cooling liquid flow channels and the refrigerant flow channels are alternately arranged and spaced apart along the length and / or width direction of the liquid cooling plate.

[0022] The liquid inlet of the cooling liquid flow channel is adjacent to the liquid outlet of the refrigerant flow channel, and the liquid outlet of the cooling liquid flow channel is adjacent to the liquid inlet of the refrigerant flow channel.

[0023] In a possible embodiment, along the length direction and / or width direction of the liquid cooling plate, the two cooling liquid flow channels are symmetrically distributed relative to the refrigerant flow channel, and the spacing between adjacent flow channels is L, and L satisfies 25 mm ≤ L ≤ 45 mm.

[0024] In one possible embodiment, along the thickness direction of the liquid cooling plate, the liquid cooling plate includes a heat exchange plate and a flow channel plate, one side of the heat exchange plate is attached to the battery pack, and the other side of the heat exchange plate is connected to the flow channel plate to enclose a coolant flow channel and a refrigerant flow channel.

[0025] In one possible embodiment, the energy storage system further includes a compressor, a heat sink, and an expansion valve. The compressor, the heat sink, and the expansion valve are all arranged in the main refrigerant circuit. The compressor is connected to the liquid outlet of the refrigerant pipeline, the other end of the compressor is connected to the heat sink, the other end of the heat sink is connected to the expansion valve, and the other end of the expansion valve is connected to the liquid inlet of the refrigerant pipeline.

[0026] The present application also provides a method for controlling liquid inlet and outlet of an energy storage system. The energy storage system is any of the energy storage systems described above, and the energy storage system further includes a valve and a liquid discharge valve. The method for controlling liquid inlet and outlet includes:

[0027] Detecting a first temperature T1 of the battery pack at the liquid inlet of the coolant flow channel; detecting a second temperature T2 of the battery pack at the liquid outlet of the coolant flow channel; when T1 and T2 satisfy T1-T2<2℃, or T2 satisfies T2<25℃, controlling the valve to rotate along a second direction y, and controlling the drain valve to open to discharge the refrigerant in the refrigerant flow channel, and the second direction y is the same as the flow direction of the refrigerant; when T1 and T2 satisfy T1-T2≥2℃, or T2 satisfies T2≥25℃, controlling the valve to rotate along a first direction x, and controlling the drain valve to close to block the refrigerant in the refrigerant flow channel from being discharged, and the first direction x is opposite to the flow direction of the refrigerant.

[0028] In the embodiment of the present application, the control system can not only control the temperature control switch to switch from the on state to the off state when the battery pack temperature is within the safe temperature range, but also control the temperature control switch to switch from the on state to the off state when the battery cell temperature difference is within the safe temperature difference range, so that the liquid cooling plate can cool the battery pack alone through the coolant; at the same time, the control system can not only control the temperature control switch to switch from the off state to the on state when the battery pack temperature exceeds the safe temperature range, but also control the temperature control switch to switch from the off state to the on state when the battery cell temperature difference exceeds the safe temperature difference range, so that the liquid cooling plate can cool the battery pack together through the coolant and the refrigerant.

[0029] This design allows the refrigerant to flow into the liquid cooling plate under specific operating conditions, achieving continuous flow of coolant within the liquid cooling plate. The intermittent flow of refrigerant within the liquid cooling plate not only improves the safety of the battery pack in high-power or high-temperature environments, but also improves the uniformity of the liquid cooling plate in cooling the battery pack under any operating state, thereby reducing the possibility of thermal runaway of the battery pack during charging and discharging, and improving the stability and reliability of the energy storage system during operation.

[0030] It should be understood that the foregoing general description and the following detailed description are merely illustrative and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0032] Figure 1 It is a schematic diagram of the energy storage system provided in this application;

[0033] Figure 2 is a top view of a liquid cooling plate provided in the present application in one embodiment;

[0034] Figure 3 This is a schematic structural diagram of a temperature control switch provided in this application in one embodiment;

[0035] Figure 4 It is a structural diagram of the liquid cooling plate and the temperature control switch;

[0036] Figure 5 It is a cross-sectional view of the temperature control switch in the closed state;

[0037] Figure 6 It is a cross-sectional view of the temperature control switch in the open state.

[0038] Description of reference numerals:

[0039] 1- Coolant circuit;

[0040] 2- Refrigerant circuit;

[0041] 21- refrigerant main line;

[0042] 22-refrigerant branch;

[0043] 3-heat exchange device;

[0044] 4-Liquid cooling plate;

[0045] 41-coolant flow channel;

[0046] 411-coolant inlet;

[0047] 412-coolant outlet;

[0048] 42-refrigerant flow channel;

[0049] 421-Refrigerant inlet;

[0050] 422-refrigerant outlet;

[0051] 43-heat exchange plate;

[0052] 44-flow channel plate;

[0053] 5- Temperature control switch;

[0054] 51-valve;

[0055] 511-first door panel;

[0056] 511a-through hole;

[0057] 512-second door panel;

[0058] 513-shaft;

[0059] 52- driving member;

[0060] 521-temperature sensing section;

[0061] 522-connection segment;

[0062] 53-connecting frame;

[0063] 531-groove;

[0064] 532- elastic member;

[0065] 6-Detection device;

[0066] 61-first detection piece;

[0067] 62- second test piece;

[0068] 7-Compressor;

[0069] 8- heat dissipation device;

[0070] 9-Expansion valve.

[0071] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. DETAILED DESCRIPTION

[0072] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0073] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0074] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0075] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0076] The embodiment of the present application provides an energy storage system, such as Figure 1 and Figure 2 As shown, the energy storage system includes a coolant circuit 1, a refrigerant circuit 2, a heat exchanger 3, a liquid cooling plate 4, and a battery pack (not shown). The refrigerant circuit 2 includes a main refrigerant circuit 21 and a branch refrigerant circuit 22. The heat exchanger 3 includes a coolant line (not shown) and a refrigerant line (not shown). The heat exchanger 3 is connected to the coolant circuit 1 via the coolant line and to the main refrigerant circuit 21 via the refrigerant line. The liquid cooling plate 4 includes a coolant flow channel 41 and a refrigerant flow channel 42. The liquid cooling plate 4 is connected to the coolant circuit 1 via the coolant flow channel 41 and to the branch refrigerant circuit 22 via the refrigerant flow channel 42. The battery pack is bonded to the liquid cooling plate 4.

[0077] The first temperature of the battery pack at the liquid inlet of the coolant channel 41 is T1, the second temperature of the battery pack at the liquid outlet of the coolant channel 41 is T2, and a temperature control switch 5 is also provided at the liquid inlet of the refrigerant channel 42.

[0078] When the temperature of the battery pack meets the first preset condition, that is, when T1 and T2 meet T1-T2<2°C, or T2 meets T2<25°C, the temperature control switch 5 is in the closed state, and the liquid cooling plate 4 cools the battery pack with the coolant.

[0079] When the temperature of the battery pack meets the second preset condition, that is, when T1 and T2 meet T1-T2≥2°C, or when T2 meets T2≥25°C, the temperature control switch 5 is in the open state, and the liquid cooling plate 4 cools the battery pack through the coolant and refrigerant.

[0080] In the embodiment of the present application, the energy storage system includes multiple battery packs, each of which is formed by multiple battery cells connected in series or parallel. Since the battery cells generate heat during the charging and discharging process, causing the temperature of the battery pack to rise, it is necessary to cool the battery pack to control the temperature of the battery cells and avoid the risk of performance degradation, shortened life or thermal runaway due to excessive temperature, so as to improve the safety of the battery cells during the charging and discharging process, thereby facilitating improving the stability and reliability of the energy storage system during operation.

[0081] To this end, in the energy storage system provided in this embodiment, the battery pack is installed on the liquid cooling plate 4 and is bonded to the surface of the liquid cooling plate 4. The coolant circuit 1 is used to circulate the coolant, and the refrigerant circuit 2 is used to circulate the refrigerant. The two are arranged in parallel and are both connected to the liquid cooling plate 4, so that the energy storage system cools the battery pack by liquid cooling.

[0082] Among them, the refrigerant circuit 2 also includes a refrigerant main circuit 21 and a refrigerant branch circuit 22 arranged in parallel, the heat exchange device 3 also includes a coolant pipeline and a refrigerant pipeline, the coolant pipeline is connected to the coolant circuit 1, and the refrigerant pipeline is connected to the refrigerant main circuit 21, the liquid cold plate 4 also includes a coolant flow channel 41 and a refrigerant flow channel 42, the coolant flow channel 41 is connected to the coolant circuit 1, and the refrigerant flow channel 42 is connected to the refrigerant branch circuit 22, and the energy storage system also includes a temperature control switch 5, which can be arranged at the connection point of the refrigerant main circuit 21 and the refrigerant branch circuit 22 to control the connection or disconnection between the refrigerant main circuit 21 and the refrigerant branch circuit 22.

[0083] Through such a design, the coolant circuit 1 and the refrigerant circuit 2 can exchange heat through the heat exchange device 3 to ensure that the coolant flowing into the liquid cold plate 4 has a lower temperature, so that it can absorb more heat, thereby improving the cooling effect of the liquid cold plate 4 on the battery pack; the liquid cold plate 4 can also cool the battery pack alone with the coolant, or cool the battery pack together with the coolant and refrigerant to ensure that the temperature of the battery pack is always maintained within a safe temperature range, thereby improving the stability and reliability of the energy storage system during operation.

[0084] At the same time, since the battery pack has temperature changes during the charging and discharging process, if the coolant is allowed to circulate alone and continuously in the liquid cooling plate 4, when the battery pack is in a high-power state or a high-temperature environment, the heat absorbed by the coolant is limited and cannot be dissipated quickly, which may easily cause the temperature of the battery pack to exceed the safe temperature range and there is a risk of thermal runaway; if the refrigerant is allowed to circulate alone and continuously in the liquid cooling plate 4, when the refrigerant flows in the refrigerant flow channel 42, the large flow resistance will cause the pressure and temperature of the refrigerant to drop, which may easily affect the cooling effect of the liquid cooling plate 4 on the battery pack, the energy consumption of the energy storage system and the stability of the energy storage system operation; if the coolant and refrigerant are allowed to circulate together and continuously in the liquid cooling plate 4, the operating cost and maintenance cost of the energy storage system will be significantly increased.

[0085] Therefore, it is necessary to control the circulation of the refrigerant in the liquid cooling plate 4 so that the refrigerant can flow into the liquid cooling plate 4 under specific working conditions, thereby realizing the continuous flow of the coolant in the liquid cooling plate 4 and the intermittent flow of the refrigerant in the liquid cooling plate 4, so as to improve the safety of the battery pack in a high power state or high temperature environment, and by reducing the proportion of the refrigerant flow channel 42, the difficulty of controlling the phase, pressure and temperature of the refrigerant in the liquid cooling plate 4 is reduced, and the operating cost and maintenance cost of the energy storage system can also be reduced.

[0086] To this end, in the energy storage system provided in this embodiment, the energy storage system can realize the circulation or blocking of the refrigerant in the liquid cooling plate 4 through the working state of the temperature control switch 5 .

[0087] The temperature control switch 5 can be installed at the liquid inlet of the refrigerant flow channel 42 to control the connection and disconnection between the refrigerant flow channel 42 and the refrigerant branch 22. When the battery pack temperature meets a first preset condition (i.e., the battery pack is in a medium-low power state or the ambient temperature is moderate), the temperature control switch 5 is closed, allowing the liquid cooling plate 4 to cool the battery pack with coolant. When the battery pack temperature meets a second preset condition (i.e., the battery pack is in a high power state or the ambient temperature is high), the temperature control switch 5 is opened, allowing the liquid cooling plate 4 to cool the battery pack with coolant and refrigerant.

[0088] Specifically, during the operation of the energy storage system, the high-temperature coolant that has absorbed the heat of the battery pack can flow out from the coolant flow channel 41 of the liquid cooling plate 4 and flow into the coolant pipeline of the heat exchange device 3 through the coolant circuit 1 to exchange heat with the refrigerant. After releasing the heat, it can flow back into the coolant flow channel 41 of the liquid cooling plate 4 through the coolant circuit 1 to continue absorbing the heat generated by the battery pack, thereby realizing the continuous flow of coolant in the liquid cooling plate 4.

[0089] Specifically, during the operation of the energy storage system, when the temperature of the battery pack meets the first preset condition, the temperature control switch 5 is in the closed state, and the refrigerant only needs to flow in the refrigerant main path 21, so that the high-temperature refrigerant that has absorbed the heat of the coolant can flow through the refrigerant main path 21 into the heat dissipation component located on the refrigerant main path 21 for heat dissipation, and after releasing the heat, it can flow back through the refrigerant main path 21 into the refrigerant pipeline of the heat exchange device 3 to exchange heat with the coolant, so as to continue to absorb the heat of the high-temperature coolant.

[0090] When the temperature of the battery pack meets the second preset condition, the temperature control switch 5 is in the on state, and the refrigerant needs to flow in the refrigerant main path 21 and the refrigerant branch path 22 at the same time, so that the low-temperature refrigerant that has released heat can be diverted, so that a part of the refrigerant flows into the refrigerant pipeline of the heat exchange device 3 through the refrigerant main path 21 to exchange heat with the coolant, and after absorbing the heat, it can be merged with the high-temperature refrigerant flowing out of the refrigerant branch path 22 through the refrigerant main path 21, and the other part of the refrigerant flows into the refrigerant flow channel 42 of the liquid cold plate 4 through the refrigerant branch path 22 to absorb the heat generated by the battery pack, and after absorbing the heat, it can flow back to the refrigerant main path 21 through the refrigerant branch path 22 for merging. The merged high-temperature refrigerant flows through the refrigerant main path 21 into the heat dissipation component located on the refrigerant main path 21 for heat dissipation, and after releasing the heat, it is diverted again to flow into the heat exchange device 3 and the liquid cold plate 4 to continue absorbing the heat of the high-temperature coolant and the heat of the battery pack, thereby realizing intermittent flow of refrigerant in the liquid cold plate 4.

[0091] Through such a design, the refrigerant can flow into the liquid cooling plate 4 under specific working conditions, so that a part of the refrigerant can continue to exchange heat with the high-temperature coolant, and the other part of the refrigerant can absorb the heat of the battery pack together with the coolant, thereby achieving continuous flow of the coolant in the liquid cooling plate 4 and intermittent flow of the refrigerant in the liquid cooling plate 4, which is beneficial to improving the safety of the battery pack in a high-power state or high-temperature environment, reducing the difficulty of controlling the phase, pressure and temperature of the refrigerant in the liquid cooling plate 4, and reducing the operating cost and maintenance cost of the energy storage system.

[0092] It should be noted that the temperature control switch 5 located at the liquid inlet of the refrigerant flow channel 42 can control the change of its working state according to a preset program through sensors, control systems, drive mechanisms and power modules, and can also autonomously change its working state according to the temperature of the battery pack through its own characteristics (such as the phase change characteristics of nickel-titanium alloy); there can be a gap between the coolant flow channel 41 and the refrigerant flow channel 42 located in the liquid cooling plate 4 to avoid the risk of mutual influence when the coolant and refrigerant flow simultaneously in the liquid cooling plate 4.

[0093] In a specific embodiment, Figure 4 、 Figure 5 and Figure 6 As shown, along the thickness direction of the liquid cooling plate 4, the liquid cooling plate 4 includes a heat exchange plate 43 and a flow channel plate 44. One side of the heat exchange plate 43 is attached to the battery pack, and the other side of the heat exchange plate 43 is connected to the flow channel plate 44 to enclose a coolant flow channel 41 and a refrigerant flow channel 42.

[0094] In this embodiment of the present application, the heat exchange plate 43 and the flow channel plate 44 are detachably connected using seals (e.g., sealing strips) and fasteners (e.g., bolts). This facilitates regular cleaning of the flow channels of the flow channel plate 44 (i.e., the coolant flow channel 41 and the refrigerant flow channel 42), thereby preventing the possibility of performance degradation of the liquid cooling plate 4 due to channel blockage. Furthermore, if the heat exchange plate 43 and / or the flow channel plate 44 are damaged, only the damaged component needs to be replaced, without replacing the liquid cooling plate 4, thus reducing maintenance costs.

[0095] The heat exchange plate 43 and the flow channel plate 44 can also be fixedly connected by welding, which is beneficial to improving the sealing of each flow channel in the liquid cooling plate 4 and improving the overall structural stability and structural strength of the liquid cooling plate 4.

[0096] With this design approach, the liquid cooling plate 4 can be designed as a split structure, so that the heat exchange plate 43 and the flow channel plate 44 can be processed separately, which helps to reduce the overall processing difficulty of the liquid cooling plate 4 and better meet actual processing requirements.

[0097] In a specific embodiment, Figure 1 As shown, the energy storage system further includes a compressor 7, a heat sink 8 and an expansion valve 9, which are all arranged in the refrigerant main path 21 to constitute the above-mentioned heat sink component for cooling the refrigerant.

[0098] Specifically, the compressor 7 is connected to the liquid outlet of the refrigerant pipeline, the other end of the compressor 7 is connected to the heat dissipation device 8, the other end of the heat dissipation device 8 is connected to the expansion valve 9, and the other end of the expansion valve 9 is connected to the liquid inlet of the refrigerant pipeline.

[0099] During the flow of the refrigerant, after the refrigerant completes heat exchange with the high-temperature coolant in the heat exchange device 3, high-temperature, low-pressure liquid refrigerant flows out of the liquid outlet of the refrigerant pipeline, and the high-temperature, low-pressure liquid refrigerant flows into the compressor 7 through the refrigerant circuit 2 for compression to form a high-temperature, high-pressure gaseous refrigerant. After the high-temperature, high-pressure gaseous refrigerant flows out of the compressor 7, it flows into the heat dissipation device 8 through the refrigerant circuit 2 for condensation and heat release to form a low-temperature, high-pressure liquid refrigerant. After the low-temperature, high-pressure liquid refrigerant flows out of the heat dissipation device 8, it flows through the refrigerant circuit 2 through the expansion valve 9 and is transformed into a low-temperature, low-pressure liquid refrigerant. At this time, the low-temperature, low-pressure liquid refrigerant can flow back to the heat exchange device 3 through the liquid inlet of the refrigerant pipeline to continue heat exchange with the high-temperature coolant.

[0100] Among them, the compressor 7 is used to increase the temperature and pressure of the refrigerant to create conditions for subsequent heat dissipation; the heat dissipation device 8 (such as a fin heat exchanger) is used to act as a condenser to reduce the heat of the refrigerant to be transferred to the external environment; the expansion valve 9 is used to adjust the flow and pressure of the refrigerant to prepare for subsequent evaporation; the heat exchange device 3 is used to act as an evaporator, so that the refrigerant absorbs the heat of the coolant in its refrigerant pipeline, evaporates into gas, and then flows back to the compressor 7.

[0101] Through such a design, the heat dissipation cycle of the refrigerant in the refrigerant main path 21 can be realized, so that the refrigerant that has absorbed heat can quickly release the heat, thereby ensuring the cooling effect of the liquid cooling plate 4 and the stable operation of the energy storage system.

[0102] In a specific embodiment, Figure 3 、 Figure 4 、 Figure 5 and Figure 6 As shown, the temperature control switch 5 includes a valve 51 and a driving member 52. The valve 51 is installed in the refrigerant flow channel 42 and is rotatably connected to the refrigerant flow channel 42. The driving member 52 is fixedly connected to the valve 51 and is used to drive the valve 51 to rotate relative to the refrigerant flow channel 42 to open or close the liquid inlet of the refrigerant flow channel 42.

[0103] The valve 51 further includes a first door plate 511 and a second door plate 512 connected to each other. The first door plate 511 has a through hole 511a. The first door plate 511 is located on the side of the second door plate 512 away from the liquid inlet of the refrigerant flow channel 42 and has a first angle with the second door plate 512.

[0104] In the embodiment of the present application, the temperature-controlled switch 5 further includes a rotating shaft 513, through which the valve 51 is rotatably connected to the inner wall of the refrigerant flow channel 42. The temperature-controlled switch 5 can be opened or closed by rotating the valve 51 relative to the refrigerant flow channel 42. This improves the response speed and control accuracy of the temperature-controlled switch 5. The driver 52 can control the opening of the valve 51 according to the temperature of the battery pack, thereby precisely adjusting the flow rate of refrigerant flowing into the refrigerant flow channel 42, thereby further conserving energy and reducing energy consumption. Furthermore, the rotating connection reduces wear on the valve 51, thereby increasing the service life and sealing reliability of the temperature-controlled switch 5. It also reduces the number of components required for the temperature-controlled switch 5, thereby reducing the production cost of the temperature-controlled switch 5.

[0105] Specifically, when the temperature of the battery pack meets the first preset condition, the temperature control switch 5 is in the closed state. At this time, the valve 51 can be rotated relative to the refrigerant flow channel 42 under the action of the driving member 52, and the valve 51 is rotated along the second direction y until the first door plate 511 and the bottom wall of the refrigerant flow channel 42 are parallel to each other. Since there is a first angle between the first door plate 511 and the second door plate 512, there is a second angle between the second door plate 512 and the bottom wall of the refrigerant flow channel 42 that is complementary to the first angle, so that the second door plate 512 and the bottom wall of the refrigerant flow channel 42 are perpendicular to each other, or are inclined relative to the bottom wall of the refrigerant flow channel 42. Figure 6 As shown, the second direction y is the same as the flow direction of the refrigerant (ie, the third direction z).

[0106] The second door panel 512 is used to block the refrigerant branch 22 and the refrigerant flow channel 42 so as to prevent the refrigerant in the refrigerant branch 22 from flowing into the refrigerant flow channel 42 along the third direction z, so that the liquid cooling plate 4 can cool the battery pack alone by the coolant to meet the cooling requirements of the battery pack in a high power state or a high temperature environment, thereby enabling the energy storage system to maintain low energy consumption operation, which is beneficial to saving energy and reducing operating costs.

[0107] Specifically, when the temperature of the battery pack meets the second preset condition, the temperature control switch 5 is in the open state. At this time, the valve 51 can rotate relative to the refrigerant flow channel 42 under the action of the driving member 52, and the valve 51 is rotated along the first direction x until the second door plate 512 and the bottom wall of the refrigerant flow channel 42 are parallel to each other. Since there is a first angle between the first door plate 511 and the second door plate 512, and the first door plate 511 has a through hole 511a, the first door plate 511 and the bottom wall of the refrigerant flow channel 42 are perpendicular to each other, or are inclined relative to the bottom wall of the refrigerant flow channel 42. Figure 5 As shown, the first direction x is opposite to the flow direction of the refrigerant (ie, the third direction z).

[0108] The first door panel 511 is used to connect the refrigerant branch 22 and the refrigerant flow channel 42, so that the refrigerant in the refrigerant branch 22 flows into the refrigerant flow channel 42 along the third direction z through the through hole 511a, so that the liquid cooling plate 4 can cool the battery pack through the coolant and the refrigerant to meet the cooling requirements of the battery pack in a high power state or a high temperature environment, so that the liquid cooling plate 4 can effectively cool the battery pack, which is beneficial to improve the safety of the battery pack during the charging and discharging process, and further improve the stability and reliability of the energy storage system during operation.

[0109] In a specific embodiment, the first door panel 511 and the second door panel 512 are an integrally formed structure.

[0110] In a specific embodiment, Figure 5 and Figure 6 As shown, the first angle between the first door panel 511 and the second door panel 512 is α, and α satisfies 120°≤α≤150°, and the second angle complementary to the first angle is β.

[0111] In an embodiment of the present application, the first angle α between the first door panel 511 and the second door panel 512 can specifically be 120°, 121°, 122°, 123°, 124°, 125°, 126°, 127°, 128°, 129°, 130°, 131°, 132°, 133°, 134°, 135°, 136°, 137°, 138°, 139°, 140°, 141°, 142°, 143°, 144°, 145°, 146°, 147°, 148°, 149°, 150°, etc.

[0112] When the first angle between the first door panel 511 and the second door panel 512 is too small (for example, α < 120°), the first angle between the two can be one of an acute angle, a right angle, and an obtuse angle. When the first angle is acute or right, the second door panel 512 may deform under the impact of the refrigerant as the refrigerant flows along the third direction z, potentially creating a gap between the second door panel 512 and the top wall of the refrigerant flow channel 42. This gap allows refrigerant to flow into the refrigerant flow channel 42, resulting in a risk of leakage when the thermostatic switch 5 is closed. When the first angle is an obtuse angle with a small degree, the complementary second angle will be larger, resulting in a longer rotational stroke of the valve 51 when the thermostatic switch 5 transitions from the closed state to the open state.

[0113] When the first angle between the first door panel 511 and the second door panel 512 is too large (for example, α>150°), since the valve 51 is installed in the refrigerant flow channel 42, the sizes of the first door panel 511 and the second door panel 512 are limited by the internal space of the refrigerant flow channel 42. If the first angle between the two is too large, it is easy to cause the size of the first door panel 511 and / or the second door panel 512 along the third direction z to become larger, so that the driving member 52 needs to provide a larger driving force to drive the valve 51 to rotate.

[0114] When the first angle between the first door panel 511 and the second door panel 512 satisfies 120°≤α≤150°, the first angle between the two is an obtuse angle, and the dimensions of the first door panel 511 and the second door panel 512 along the third direction z are moderate.

[0115] When the temperature control switch 5 is in the closed state, the second door panel 512 will be inclined relative to the bottom wall of the refrigerant flow channel 42 and abut against the top wall of the refrigerant flow channel 42. In the process of the refrigerant flowing along the third direction z, the refrigerant will continuously impact the second door panel 512 and cause it to rotate along the second direction y. However, since the second door panel 512 is located on the side of the first door panel 511 close to the liquid inlet of the refrigerant flow channel 42, the second door panel 512 will gradually increase the force between the second door panel 512 and the top wall of the refrigerant flow channel 42 under the impact of the refrigerant, thereby effectively blocking the flow of refrigerant along the third direction z, thereby improving the sealing of the temperature control switch 5 in the closed state.

[0116] When the temperature-controlled switch 5 switches from the closed state to the open state, the driver 52 only needs to rotate the valve 51 a small angle in the first direction x to open the gap between the second door panel 512 and the top wall of the refrigerant flow channel 42, allowing refrigerant to flow into the refrigerant flow channel 42 through this gap. This helps reduce the difficulty of controlling the temperature-controlled switch 5 during the transition between operating states. Furthermore, the second angle, which is complementary to the first angle, is smaller, shortening the rotational travel of the valve 51, allowing the temperature-controlled switch 5 to easily change its operating state.

[0117] Therefore, by setting the first angle between the first door panel 511 and the second door panel 512 to an obtuse angle satisfying 120°≤α≤150°, the possibility of the valve 51 rotating arbitrarily under the impact of the refrigerant can be reduced, thereby improving the sealing of the temperature control switch 5 in the closed state, and reducing the control difficulty of the temperature control switch 5 in the process of changing the working state, thereby ensuring the stability and reliability of the energy storage system during operation.

[0118] In a specific embodiment, the second door panel 512 is provided with a sealing member. When the temperature control switch 5 is in the closed state, the second door panel 512 abuts against the inner wall of the refrigerant flow channel 42 through the sealing member.

[0119] In an embodiment of the present application, a seal is provided to enable the second door panel 512 to be sealedly connected to the inner wall of the refrigerant flow channel 42 so as to improve the sealing between the two, thereby further reducing the possibility of refrigerant flowing into the refrigerant flow channel 42 when the temperature control switch 5 is in the closed state.

[0120] Specifically, the side wall of the second door panel 512 can be provided with a receiving groove for accommodating the seal, so as to reduce the possibility of the seal being separated from the second door panel 512 during the rotation of the valve 51, and improve the stability and reliability of the connection between the second door panel 512 and the seal.

[0121] More specifically, the projection of the seal along the third direction z can be one of C-shape, U-shape or O-shape, so that the second door panel 512 can abut against the top wall of the refrigerant flow channel 42 through the seal, and can also abut against the side wall of the refrigerant flow channel 42 through the seal, and can even abut against the bottom wall of the refrigerant flow channel 42 through the seal, thereby realizing the blocking of the liquid inlet of the refrigerant flow channel 42 by the second door panel 512, which is beneficial to improving the reliability of the sealing connection between the second door panel 512 and the inner wall of the refrigerant flow channel 42.

[0122] It should be noted that when the second door panel 512 is sealed to the inner wall of the refrigerant flow channel 42 through the seal, during the process of the temperature control switch 5 changing the working state, the force applied by the drive member 52 to the valve 51 will increase accordingly to overcome the friction between the seal and the inner wall of the refrigerant flow channel 42, so as to ensure that the valve 51 can rotate smoothly in the first direction x or the second direction y, thereby ensuring the flexibility and reliability of the temperature control switch 5.

[0123] In a specific embodiment, Figure 3 、 Figure 4 、 Figure 5 and Figure 6 As shown, the driving member 52 is a shape memory alloy. Along the thickness direction of the liquid cooling plate 4 , one end of the shape memory alloy is connected to the first door panel 511 , and the other end of the shape memory alloy is connected to the top wall of the refrigerant flow channel 42 .

[0124] Among them, when the temperature of the battery pack meets the second preset condition, the shape memory alloy can shrink and drive the first door panel 511 to move along the first direction x to open the liquid inlet of the refrigerant flow channel 42. When the temperature of the battery pack meets the first preset condition, the shape memory alloy can return to its initial state and drive the first door panel 511 to move along the second direction y to close the liquid inlet of the refrigerant flow channel 42. The first direction x is opposite to the second direction y.

[0125] In the embodiment of the present application, when the driver 52 is a shape memory alloy, the driver 52 can drive the valve 51 to rotate in the first direction x or the second direction y according to the temperature of the battery pack through its own characteristics, thereby controlling the temperature control switch 5 to switch between the closed state and the open state. This allows the temperature control switch 5 to autonomously change its operating state according to the temperature of the battery pack, which is beneficial for improving the sensitivity of the temperature control switch 5. It no longer needs to be controlled by signals from components such as sensors and control systems, resulting in a faster response speed, thereby ensuring the safety and service life of the battery pack. At the same time, this design approach can also reduce the number of components such as sensors, control systems, and power modules that cooperate with the temperature control switch 5 in the energy storage system, which is beneficial for simplifying the overall complexity and energy consumption of the energy storage system, thereby reducing the operating cost of the energy storage system. In addition, shape memory alloys have good stability during deformation, good corrosion resistance, and a long service life. This prevents the mechanical components of the driver 52 from being easily worn during movement, which is beneficial for ensuring the stability and reliability of the driver 52 during operation, thereby significantly extending the service life of the temperature control switch 5.

[0126] Specifically, since the shape memory alloy is relatively sensitive to temperature changes, the shape memory alloy can sense the temperature of the battery pack through the liquid cooling plate 4 in real time and can deform as the temperature of the battery pack changes.

[0127] During the deformation process of the shape memory alloy, since the shape memory alloy has a preset shape in the high-temperature phase (austenite phase) and can be stretched and deformed by external force in the low-temperature phase (martensite phase), when the temperature of the battery pack exceeds the safe temperature range, the crystal structure inside the shape memory alloy will change from the martensite phase to the austenite phase, thereby generating a contraction force and restoring to the preset shape in the high-temperature phase (i.e., the shape memory alloy shrinks and deforms). When the temperature of the battery pack drops back to the safe temperature range, the crystal structure inside the shape memory alloy will change from the austenite phase to the martensite phase, thereby generating a tensile force and deforming to the preset shape in the low-temperature phase (i.e., the shape memory alloy stretches and deforms).

[0128] The driving member 52 further includes a temperature sensing section 521 and a connecting section 522 connected to each other. The temperature sensing section 521 is connected to the top wall of the refrigerant flow channel 42 , and the connecting section 522 is connected to an end of the first door panel 511 away from the second door panel 512 .

[0129] When the temperature-sensing section 521 senses that the temperature of the battery pack does not exceed the safe temperature range (that is, when the temperature of the battery pack meets the first preset condition), the shape memory alloy as a whole can be maintained in the initial preset shape (that is, the preset shape of the low-temperature phase) to limit the rotation of the first door panel 511 along the first direction x, thereby ensuring the sealing of the temperature control switch 5 in the closed state.

[0130] When the temperature-sensing section 521 senses that the temperature of the battery pack exceeds the safe temperature range (i.e., when the temperature of the battery pack meets the second preset condition), the shape memory alloy as a whole can deform at the same time as the battery pack temperature exceeds the safe temperature range, and maintain the preset shape after deformation (i.e., the preset shape of the high-temperature phase), thereby pulling the first door panel 511 to rotate along the first direction x, thereby allowing the temperature control switch 5 to be timely switched from the closed state to the open state, so that the refrigerant can flow into the refrigerant flow channel 42 through the first through hole 511a of the first door panel 511, so that the liquid cooling plate 4 cools the battery pack through the coolant and the refrigerant.

[0131] At the same time, when the temperature-sensing section 521 senses that the temperature of the battery pack has dropped to a safe temperature range, the shape memory alloy as a whole can restore to its initial preset shape (i.e., the preset shape of the low-temperature phase) when the temperature of the battery pack drops back to the safe temperature range, thereby driving the first door panel 511 to rotate along the second direction y, and thus enabling the temperature control switch 5 to be able to change from the open state to the closed state in a timely manner, so as to block the liquid inlet of the refrigerant flow channel 42 through the second door panel 512, so that the liquid cooling plate 4 can cool the battery pack alone through the coolant.

[0132] In a specific embodiment, the top wall of the refrigerant flow channel 42 is provided with a cavity (not marked in the figure) for accommodating the temperature sensing section 521, so that the temperature sensing section 521 of the shape memory alloy is limitedly connected to the top wall of the refrigerant flow channel 42, thereby ensuring that the shape memory alloy can drive the first door panel 511 to rotate along the first direction x or the second direction y through the shape memory alloy connecting section 522 during the deformation process.

[0133] In a specific embodiment, when the driving member 52 is a shape memory alloy, the material of the driving member 52 can be a nickel-titanium alloy, such as Ni50Ti48Zr2, so that the phase transition temperature of the driving member 52 is 25° C. Shape memory alloys with different phase transition temperatures can also be obtained by changing the ratio of different elements in the material and / or adding or removing elements.

[0134] In a specific embodiment, the temperature sensing section 521 and the connecting section 522 are an integrally formed structure.

[0135] In a specific embodiment, Figure 3 and Figure 4 As shown, the refrigerant flow channel 42 is also provided with a groove 531, and the temperature control switch 5 also includes a guide column (not marked in the figure) and an elastic member 532. The guide column is arranged on the bottom wall of the groove 531, and the elastic member 532 is sleeved on the outer wall of the guide column, and one end of the elastic member 532 is connected to the bottom wall of the groove 531, and the other end of the elastic member 532 is connected to the first door panel 511.

[0136] In an embodiment of the present application, the groove 531 is used to accommodate a guide column and an elastic member 532. The elastic member 532 can be elastically deformed and is used to provide a pulling force to the first door panel 511, so that the first door panel 511 can remain parallel to the bottom wall of the refrigerant flow channel 42, so as to improve the sealing of the temperature control switch 5 in the closed state, and promote the rotation of the valve 51 along the second direction y during the transition from the open state to the closed state, so as to improve the smoothness of the valve 51 resetting. The guide column can limit the deformation direction of the elastic member 532 during the deformation process, avoid the elastic member 532 from being dislocated during the elastic deformation process, and thus enable the elastic member 532 to be smoothly reset.

[0137] Specifically, when the temperature-sensing section 521 senses that the temperature of the battery pack does not exceed the safe temperature range (that is, when the temperature of the battery pack meets the first preset condition), the temperature of the battery pack (that is, the temperature of the shape memory alloy) is lower than the phase transition temperature of the shape memory alloy, so that the contraction force of the shape memory alloy is less than the tension of the elastic member 532, so that the first door panel 511 can remain parallel to the bottom wall of the refrigerant flow channel 42, and the second door panel 512 can remain inclined with respect to the bottom wall of the refrigerant flow channel 42, thereby enabling the temperature control switch 5 to remain in a closed state to block the liquid inlet of the refrigerant flow channel 42 and prevent the inflow of refrigerant.

[0138] Specifically, when the temperature sensing section 521 senses that the temperature of the battery pack exceeds the safe temperature range (that is, when the temperature of the battery pack meets the second preset condition), the temperature of the battery pack (that is, the temperature of the shape memory alloy) is higher than the phase change temperature of the shape memory alloy, so that the contraction force of the shape memory alloy is greater than the pulling force of the elastic member 532, and the shape memory alloy can pull the first door panel 511 to rotate along the first direction x, so that the first door panel 511 can be inclined with respect to the bottom wall of the refrigerant flow channel 42, and the second door panel 512 can be parallel to the bottom wall of the refrigerant flow channel 42, thereby enabling the temperature control switch 5 to be in the open state to open the liquid inlet of the refrigerant flow channel 42 so that the refrigerant can flow in.

[0139] Specifically, when the temperature sensing section 521 senses that the temperature of the battery pack has dropped back to a safe temperature range (that is, when the temperature of the battery pack meets the first preset condition), the temperature of the battery pack (that is, the temperature of the shape memory alloy) is lower than the phase transition temperature of the shape memory alloy, so that the contraction force of the shape memory alloy is less than the pulling force of the elastic member 532. The elastic member 532 can pull the first door panel 511 to rotate along the second direction y, so that the first door panel 511 and the bottom wall of the refrigerant flow channel 42 are restored to a parallel setting, and the second door panel 512 and the bottom wall of the refrigerant flow channel 42 are restored to an inclined setting, thereby allowing the temperature control switch 5 to be restored to a closed state to re-block the liquid inlet of the refrigerant flow channel 42 and block the inflow of refrigerant.

[0140] In a specific embodiment, the temperature control switch 5 also includes a connecting frame 53, and the above-mentioned valve 51, rotating shaft 513, driving member 52, groove 531, guide column and elastic member 532 can all be arranged on the connecting frame 53. When the connecting frame 53 is connected to the refrigerant flow channel 42 of the liquid cooling plate 4, the connecting frame 53 can serve as a liquid inlet of the refrigerant flow channel 42.

[0141] In one specific embodiment, the connecting bracket 53 is detachably connected to the refrigerant flow channel 42 of the liquid cooling plate 4. This allows for the replacement or maintenance of components such as the valve 51 and the rotating shaft 513 by simply removing the connecting bracket 53 from the liquid cooling plate 4, without having to completely replace the liquid cooling plate 4. This improves maintenance efficiency and reduces maintenance costs. This design also enhances the versatility of the temperature control switch 5, allowing it to be installed at the inlet or outlet of any flow channel on the liquid cooling plate 4 to meet other requirements of the liquid cooling plate 4 and the energy storage system.

[0142] In a specific embodiment, when one end of the elastic member 532 is fixedly connected to the bottom wall of the groove 531 and the other end of the elastic member 532 is fixedly connected to the first door panel 511, a guide column may not be required in the groove 531 to further simplify the structure of the temperature control switch 5.

[0143] In a specific embodiment, the energy storage system further includes a drain valve (not shown in the figure), which is installed on the bottom wall of the groove 531. When the temperature of the battery pack meets a first preset condition, the drain valve is in an open state to discharge the refrigerant in the groove 531. When the temperature of the battery pack meets a second preset condition, the drain valve is in a closed state to prevent the refrigerant in the groove 531 from being discharged.

[0144] In the embodiment of the present application, because a groove 531 is provided at the liquid inlet of the refrigerant flow channel 42 (or at the connecting bracket 53), when the temperature-controlled switch 5 is in the open state, refrigerant flows through the refrigerant flow channel 42, causing some refrigerant to flow into the groove 531. Even after the temperature-controlled switch 5 is switched to the closed state, the refrigerant will remain in the groove 531. If excessive refrigerant remains in the groove 531, there is a possibility that the residual refrigerant will affect the normal operation of the temperature-controlled switch 5 (for example, if the ambient temperature is too low, the refrigerant in the groove 531 may freeze, causing the valve 51 to be unable to rotate). Therefore, it is necessary to drain the refrigerant remaining in the groove 531 to ensure the stability and reliability of the temperature-controlled switch 5 during operation.

[0145] Specifically, when the temperature of the battery pack meets the first preset condition, the temperature control switch 5 is in the closed state. At this time, no refrigerant needs to flow in the refrigerant flow channel 42, so that the liquid cooling plate 4 can cool the battery pack alone through the coolant. Therefore, the drain valve can be controlled to be in the open state to connect the bottom wall of the groove 531 with the external environment or the recovery pipeline, so that the residual refrigerant can be discharged from the groove 531.

[0146] If the sealing performance of the temperature control switch 5 is reduced, causing part of the refrigerant to penetrate into the refrigerant flow channel 42 , the refrigerant can also be discharged through the drain valve in the groove 531 for recycling.

[0147] Specifically, when the temperature of the battery pack meets the second preset condition, the temperature control switch 5 is in the open state. At this time, refrigerant needs to flow in the refrigerant flow channel 42 so that the liquid cooling plate 4 can cool the battery pack through the coolant and refrigerant. Therefore, the drain valve can be controlled to be in a closed state to block the bottom wall of the groove 531 from the external environment or the recovery pipeline, so that the refrigerant can flow stably in the refrigerant flow channel 42 to absorb the heat generated by the battery pack.

[0148] This design allows the valve 51 and the drain valve to operate in opposite states. When valve 51 connects the refrigerant branch 22 and the refrigerant flow channel 42, closing the drain valve seals the refrigerant flow channel 42, thereby preventing the risk of refrigerant leakage during flow. This helps reduce refrigerant loss, ensures stable refrigerant pressure during flow, and thus ensures the cooling performance of the liquid cold plate 4 on the battery pack. When valve 51 blocks the refrigerant branch 22 and the refrigerant flow channel 42, opening the drain valve opens the refrigerant flow channel 42, actively draining any remaining refrigerant from the refrigerant flow channel 42 and reducing the pressure within the refrigerant flow channel 42, thereby reducing the impact of residual refrigerant on the sealing performance of valve 51. Furthermore, during the operation of the energy storage system, timely draining residual refrigerant from the refrigerant flow channel 42 avoids the risk of corrosion or impurity deposition in the refrigerant flow channel 42 caused by prolonged retention of residual refrigerant, thereby ensuring the stability and reliability of the energy storage system.

[0149] It should be noted that the drain valve located on the bottom wall of the groove 531 can control the changes in its working state according to a preset program through sensors, control systems, drive mechanisms and power modules, or the working state of the drain valve can be manually controlled by staff according to the amount of residual refrigerant in the groove 531.

[0150] In a specific embodiment, both the valve 51 and the drain valve can control the changes in their working states according to a preset program through sensors, control systems, drive mechanisms and power modules, so that the two can work together, which is beneficial to improving the flexibility of the liquid cooling plate 4 when switching working states.

[0151] In a specific embodiment, along the thickness direction of the liquid cooling plate 4 , the cross-sectional shape of the groove 531 can be rectangular, trapezoidal, triangular or semicircular.

[0152] In the embodiment of the present application, such a design method can concentrate the refrigerant in the groove 531 at the bottom of the groove 531, so that the refrigerant can flow out of the groove 531 smoothly after the drain valve is opened, thereby ensuring that the refrigerant remaining in the groove 531 is discharged as much as possible, reducing the possibility of refrigerant remaining in the groove 531.

[0153] In a specific embodiment, the volume of the groove 531 is V, and V satisfies 1 ml ≤ V ≤ 10 ml.

[0154] In the embodiment of the present application, the volume V of the groove 531 can be 1ml, 1.2ml, 1.4ml, 1.6ml, 1.8ml, 2ml, 2.2ml, 2.4ml, 2.6ml, 2.8ml, 3ml, 3.2ml, 3.4ml, 3.6ml, 3.8ml, 4ml, 4.2ml, 4.4ml, 4.6ml, 4.8ml, 5ml, 5.2ml, 5.4ml, 5.6ml, 5.8ml, 6ml, 6.2ml, 6.4ml, 6.6ml, 6.8ml, 7ml, 7.2ml, 7.4ml, 7.6ml, 7.8ml, 8ml, 8.2ml, 8.4ml, 8.6ml, 8.8ml, 9ml, 9.2ml, 9.4ml, 9.6ml, 9.8ml, 10ml, etc.

[0155] When the volume of the groove 531 satisfies 1ml≤V≤10ml, the groove 531 can ensure that there is less refrigerant remaining in the groove 531 while having a space sufficient to accommodate the guide column and the elastic member 532, which is beneficial to reducing the loss of the refrigerant and can reduce the possibility of the residual refrigerant affecting the working state of the temperature control switch 5, thereby ensuring the working performance of the liquid cooling plate 4 and the operating state of the energy storage system.

[0156] In a specific embodiment, Figure 2As shown, the energy storage system also includes a control system (not shown) and a detection device 6. The control system is electrically or signal-connected to the detection device 6, and is also electrically or signal-connected to the drain valve and / or the driver 52. The detection device 6 is mounted on the side of the liquid cooling plate 4 facing the battery pack and is used to detect the temperature of the battery pack. The control system is used to control the start or stop of the driver 52 and / or the opening or closing of the drain valve based on the detection results of the detection device 6.

[0157] In the embodiment of the present application, when the control system is electrically or signal-connected to the driver 52, the driver 52 may be a drive mechanism such as a motor. The detection device 6 is configured to detect the temperature of the battery pack and transmit the detection results to the control system in real time, so that the control system can determine whether the battery pack temperature meets the first preset condition or the second preset condition based on the detection results of the detection device 6.

[0158] When the control system determines that the temperature of the battery pack meets the first preset condition, the control system can control the driving member 52 to drive the valve 51 to rotate along the second direction y to block the refrigerant branch 22 and the refrigerant flow channel 42; when the control system determines that the temperature of the battery pack meets the second preset condition, the control system can control the driving member 52 to drive the valve 51 to rotate along the first direction x to connect the refrigerant branch 22 and the refrigerant flow channel 42.

[0159] Therefore, the control system can control the temperature control switch 5 to switch from the off state to the on state when the battery pack temperature exceeds the safe temperature range, so that the liquid cooling plate 4 can cool the battery pack with both the coolant and the refrigerant. This improves the sensitivity and response speed of the driver 52, thereby enhancing the safety of the battery pack in high-power states or high-temperature environments. The control system can also control the temperature control switch 5 to switch from the on state to the off state when the battery pack temperature drops back to the safe temperature range, so that the liquid cooling plate 4 can cool the battery pack independently with the coolant. This reduces the control system's difficulty in controlling the refrigerant phase, pressure, and temperature within the liquid cooling plate 4, thereby reducing the operating and maintenance costs of the energy storage system.

[0160] At the same time, when the control system is electrically connected or signal-connected to the drain valve, the detection device 6 is used to detect the temperature of the battery pack and transmit the detection results to the control system in real time, so that the control system can judge whether the temperature of the battery pack meets the first preset condition or the second preset condition based on the detection results of the detection device 6.

[0161] When the control system determines that the temperature of the battery pack meets the first preset condition, since the temperature control switch 5 will be in the closed state, the control system can control the drain valve to open to connect the bottom wall of the groove 531 with the external environment or the recovery pipeline, so that the refrigerant remaining in the groove 531 can be discharged; when the control system determines that the temperature of the battery pack meets the second preset condition, since the temperature control switch 5 will be in the open state, the control system can control the drain valve to close to block the bottom wall of the groove 531 from the external environment or the recovery pipeline, so that the refrigerant can flow stably in the refrigerant flow channel 42 to absorb the heat generated by the battery pack, thereby improving the ability of the liquid cooling plate 4 to cool the battery pack.

[0162] It should be noted that when the driver 52 is a shape memory alloy, the control system can be electrically or signal-connected to the detection device 6 and the drain valve, allowing the shape memory alloy to autonomously change its operating state based on the battery pack temperature. This improves the sensitivity of the driver 52, allowing the control system to control the operating state of the drain valve based on the signal from the detection device 6, thereby reducing the complexity and design difficulty of the control system. When the driver 52 is a drive mechanism such as a motor, the control system can be electrically or signal-connected to the detection device 6, the drain valve, and the driver 52, respectively, allowing the control system to control the operating state of the driver 52 and the drain valve based on the signal from the detection device 6. This facilitates better coordination of their operating states and more compact coordination between the valve 51 and the drain valve during operation.

[0163] In a specific embodiment, Figure 2 As shown, the liquid cooling plate 4 includes at least two cooling liquid channels 41 and at least one refrigerant channel 42 . The cooling liquid channels 41 and the refrigerant channels 42 are alternately arranged and spaced apart along the length and / or width direction of the liquid cooling plate 4 .

[0164] The liquid inlet of the coolant flow channel 41 is adjacent to the liquid outlet of the refrigerant flow channel 42 , and the liquid outlet of the coolant flow channel 41 is adjacent to the liquid inlet of the refrigerant flow channel 42 .

[0165] In the embodiment of the present application, taking the liquid cooling plate 4 including two cooling liquid flow channels 41 and one refrigerant flow channel 42 as an example, the two cooling liquid flow channels 41 are arranged at intervals along the length direction and / or width direction of the liquid cooling plate 4, the refrigerant flow channel 42 is located between the two cooling liquid flow channels 41, and has at least a partial distance between the two cooling liquid flow channels 41, and the three flow channels are located in the same plane.

[0166] By alternately arranging the coolant flow channels 41 and the refrigerant flow channels 42 along the length direction and / or width direction of the liquid cooling plate 4, the coolant flow channels 41 and the refrigerant flow channels 42 can be distributed more evenly on the liquid cooling plate 4, thereby improving the uniformity of cooling the battery pack by the liquid cooling plate 4, thereby avoiding the risk of local overheating of the battery pack during charging and discharging, and thus helping to improve the safety of the battery pack.

[0167] Among them, since the coolant flow channel 41 and the refrigerant flow channel 42 can be arranged alternately in the same plane of the liquid cooling plate 4, the design of multi-layer stacking of the flow channels can be avoided, thereby reducing the overall thickness of the liquid cooling plate 4, and further reducing the space occupied by the liquid cooling plate 4 in the energy storage system to meet the requirements of a compact layout inside the energy storage system.

[0168] At the same time, by setting the interval distribution between adjacent flow channels, it can be ensured that the coolant in the coolant flow channel 41 and the refrigerant in the refrigerant flow channel 42 can fully absorb the heat generated by the battery pack, which is beneficial to improving the heat exchange efficiency.

[0169] In addition, by arranging the coolant inlet 411 and the refrigerant outlet 422 adjacent to each other, and the coolant outlet 412 and the refrigerant inlet 421 adjacent to each other, each coolant flow channel 41 and each refrigerant flow channel 42 can be made independent of each other. During the operation of the energy storage system, if any flow channel is blocked or leaks, the remaining flow channels can still provide cooling capabilities. Moreover, by arranging the flow directions of the coolant and the refrigerant in opposite directions, the temperature difference between the liquid inlet of the coolant flow channel 41 and the liquid inlet of the refrigerant flow channel 42 is small, which is beneficial to improving the uniformity of heat exchange between the liquid cold plate 4 as a whole and the battery pack, thereby improving the stability and reliability of the energy storage system during operation.

[0170] In a specific embodiment, Figure 2 As shown, along the length direction and / or width direction of the liquid cooling plate 4, the two cooling liquid flow channels 41 are symmetrically distributed relative to the refrigerant flow channel 42, and the spacing between adjacent flow channels is L, and L satisfies 25mm≤L≤45mm.

[0171] In the embodiment of the present application, by arranging two cooling liquid flow channels 41 to be symmetrically distributed relative to the refrigerant flow channel 42, the spacing between each flow channel can be made equal, thereby further improving the uniformity of the distribution of the cooling liquid flow channel 41 and the refrigerant flow channel 42 on the liquid cooling plate 4, so as to avoid the uneven heat exchange between the liquid cooling plate 4 and the battery pack due to the asymmetric layout of the flow channels, thereby improving the safety and reliability of the battery pack during the charging and discharging process, and ensuring the stable operation of the energy storage system.

[0172] Specifically, the spacing L between adjacent flow channels can be 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, etc.

[0173] When the spacing between adjacent flow channels satisfies 25mm≤L≤45mm, it can ensure that the coolant flow channel 41 and the refrigerant flow channel 42 occupy a larger area ratio on the liquid cooling plate 4 while reducing the interaction between adjacent flow channels to ensure that the coolant and refrigerant can fully absorb the heat generated by the battery pack, thereby improving the heat exchange efficiency with the liquid cooling plate 4.

[0174] In a specific embodiment, along the thickness direction of the liquid cooling plate 4 , the projected area of the coolant flow channel 41 is S1 , the projected area of the refrigerant flow channel 42 is S2 , and S1 and S2 satisfy 0.5≤S2 / S1≤1.

[0175] In the embodiment of the present application, the ratio of the projected area between the refrigerant flow channel 42 and the coolant flow channel 41 can be 0.5, 0.52, 0.54, 0.56, 0.58, 0.6, 0.62, 0.64, 0.66, 0.68, 0.7, 0.72, 0.74, 0.76, 0.78, 0.8, 0.82, 0.84, 0.86, 0.88, 0.9, 0.92, 0.94, 0.96, 0.98, 1, etc.

[0176] When the ratio of the projected areas of the refrigerant flow channel 42 and the cooling liquid flow channel 41 satisfies 0.5≤S2 / S1≤1, the area ratio of the cooling liquid flow channel 41 on the liquid cooling plate 4 is greater than the area ratio of the refrigerant flow channel 42 on the liquid cooling plate 4, so that the liquid cooling plate 4 still has good heat exchange capacity when the cooling liquid circulates alone inside it, so that the liquid cooling plate 4 can effectively cool the battery pack, thereby ensuring the safety and reliability of the battery pack during the charging and discharging process.

[0177] In a specific embodiment, along the length direction and / or width direction of the liquid cooling plate 4 , the number of the cooling liquid flow channels 41 is a, the number of the refrigerant flow channels 42 is b, and a and b satisfy ab=1.

[0178] In a specific embodiment, along the thickness direction of the liquid cooling plate 4 , the flow cross-sectional area of the coolant flow channel 41 is S3 , the flow cross-sectional area of the refrigerant flow channel 42 is S4 , and S3 and S4 satisfy 0.5≤S3 / S4≤1.

[0179] In the embodiment of the present application, the ratio of the flow cross-sectional area between the coolant flow channel 41 and the refrigerant flow channel 42 can be 0.5, 0.51, 0.53, 0.55, 0.57, 0.59, 0.61, 0.63, 0.65, 0.67, 0.69, 0.71, 0.73, 0.75, 0.79, 0.81, 0.83, 0.85, 0.87, 0.89, 0.91, 0.93, 0.95, 0.97, 0.99, 1, etc.

[0180] When the ratio of the flow cross-sectional area between the coolant flow channel 41 and the refrigerant flow channel 42 satisfies 0.5≤S3 / S4≤1, the flow cross-sectional area of any coolant flow channel 41 does not exceed the flow cross-sectional area of any refrigerant flow channel 42, so that the refrigerant flow channel 42 can reduce the flow velocity of the refrigerant during the flow process through a larger flow cross-sectional area, thereby reducing the pressure drop and ensuring that the refrigerant can fully absorb the heat generated by the battery pack, thereby providing good cooling and cooling capabilities, so that in the process of the liquid cooling plate 4 cooling the battery pack through the coolant and refrigerant, it is beneficial to significantly improve the heat exchange efficiency of the liquid cooling plate 4 and improve the uniformity of cooling the battery pack, thereby ensuring the safety and reliability of the battery pack during the charging and discharging process.

[0181] In a specific embodiment, along the thickness direction of the liquid cooling plate 4 , the projected shapes of the cooling liquid flow channel 41 and the refrigerant flow channel 42 are both linear structures.

[0182] In the embodiment of the present application, the coolant flow channel 41 and the refrigerant flow channel 42 can be in the form of a linear structure such as a straight line, a curve, or a serpentine. This design approach allows each flow channel to extend longer, thereby increasing the flow time of the coolant and refrigerant within each flow channel, which is beneficial for improving the effective utilization rate of the coolant and refrigerant. At the same time, along the thickness direction of the liquid cooling plate 4, the projection of the coolant flow channel 41 and the refrigerant flow channel 42 can cover a larger area of the liquid cooling plate 4, thereby facilitating an increase in the heat exchange area between the liquid cooling plate 4 and the battery pack, thereby improving the efficiency of the liquid cooling plate 4 in cooling the battery pack and the heat exchange efficiency between the two.

[0183] The embodiment of the present application also provides a method for controlling the liquid inlet and outlet of an energy storage system, such as Figure 2 As shown, the detection device 6 includes a first detection member 61 and a second detection member 62 electrically connected or signal-connected to the control system. Along the thickness direction of the liquid cooling plate 4, the first detection member 61 and the second detection member 62 are both installed on the side of the liquid cooling plate 4 facing the battery pack, and the first detection member 61 is located at the liquid inlet of the cooling liquid flow channel 41, and the second detection member 62 is located at the liquid outlet of the cooling liquid flow channel 41. The liquid inlet and discharge control method includes:

[0184] The first detection component 61 detects the first temperature T1 of the battery pack at the liquid inlet of the coolant flow channel 41; the second detection component 62 detects the second temperature T2 of the battery pack at the liquid outlet of the coolant flow channel 41; when the first temperature and the second temperature satisfy T1-T2<2℃, or the second temperature satisfies T2<25℃, the control system controls the valve 51 to rotate along the second direction y, and controls the drain valve to open to discharge the refrigerant in the groove 531; when the first temperature and the second temperature satisfy T1-T2≥2℃, or the second temperature satisfies T2≥25℃, the control system controls the valve 51 to rotate along the first direction x, and controls the drain valve to close to prevent the refrigerant in the groove 531 from being discharged.

[0185] Among them, when the temperature of the battery pack meets the first preset condition, the first preset condition is that the first temperature and the second temperature meet T1-T2<2℃, or the second temperature meets T2<25℃; when the temperature of the battery pack meets the second preset condition, the second preset condition is that the first temperature and the second temperature meet T1-T2≥2℃, or the second temperature meets T2≥25℃.

[0186] In the embodiment of the present application, when the liquid cooling plate 4 cools the battery pack using the coolant alone, the coolant in the coolant channel 41 flows unidirectionally along its extension direction, causing the coolant's heat absorption capacity to gradually decrease as the coolant flows. This results in a temperature difference between the temperature of the battery cells at the outlet of the coolant channel 41 and the temperature of the battery cells at the inlet of the coolant channel 41 (i.e., a difference between the first temperature and the second temperature), which can easily lead to a reduction in the uniformity of the cooling of the battery pack by the liquid cooling plate 4. Furthermore, if the temperature difference between the battery cells in the battery pack is large during the charge and discharge process of the battery pack, it can easily lead to a reduction in the charge and discharge efficiency of the battery pack and an increased risk of thermal runaway, thereby affecting the service life of the battery pack and the stability and reliability of the energy storage system during operation.

[0187] Therefore, not only is it necessary for the control system to control the temperature control switch 5 to change the working state when the battery pack temperature exceeds the safe temperature range, but the control system is also required to control the temperature control switch 5 to change the working state when the temperature difference of the battery cells in the battery pack exceeds the safe temperature difference range, so as to ensure the charging and discharging efficiency of the battery pack and reduce the possibility of thermal runaway of the battery pack, thereby extending the service life of the battery pack and improving the stability and reliability of the energy storage system during operation.

[0188] To this end, in the liquid inlet and discharge control method provided in this embodiment, the first preset condition is that T1 and T2 satisfy T1-T2<2℃, or T2 satisfies T2<25℃, and the second preset condition is that T1 and T2 satisfy T1-T2≥2℃, or T2 satisfies T2≥25℃, so that the temperature control switch 5 can not only switch from the closed state to the open state when the battery pack temperature exceeds the safe temperature range, but also switch from the closed state to the open state when the temperature difference of the battery cells in the battery pack exceeds the safe temperature difference range.

[0189] The temperature control switch 5 can be disposed at the liquid inlet of the refrigerant flow channel 42 to control the connection or disconnection between the refrigerant flow channel 42 and the refrigerant branch 22. When the battery pack temperature meets a first preset condition (i.e., T1 and T2 meet T1-T2 < 2°C, or T2 meets T2 < 25°C), the temperature control switch 5 is closed and the drain valve is open, allowing the liquid cooling plate 4 to cool the battery pack solely with the coolant. When the battery pack temperature meets a second preset condition (i.e., T1 and T2 meet T1-T2 ≥ 2°C, or T2 meets T2 ≥ 25°C), the temperature control switch 5 is open and the drain valve is closed, allowing the liquid cooling plate 4 to cool the battery pack jointly with the coolant.

[0190] Specifically, when the battery pack temperature meets a first preset condition (i.e., the first and second temperatures meet T1-T2 < 2°C, or the second temperature meets T2 < 25°C), the temperature control switch 5 is closed and the drain valve is open. At this point, the refrigerant only needs to flow within the main refrigerant path 21. This allows the high-temperature refrigerant, having absorbed heat from the coolant, to flow through the main refrigerant path 21 to the heat dissipation assembly located therein for heat dissipation. After releasing heat, the refrigerant can then flow back through the main refrigerant path 21 into the refrigerant pipeline of the heat exchange device 3 to exchange heat with the coolant, continuing to absorb heat from the high-temperature coolant. At the same time, refrigerant is not required to flow through the refrigerant flow channel 42, allowing the liquid cold plate 4 to cool the battery pack solely through the coolant. Therefore, the drain valve can be controlled to remain open, connecting the bottom wall of the recess 531 to the external environment or a recovery pipeline, allowing any remaining refrigerant to drain out of the recess 531.

[0191] Specifically, when the temperature of the battery pack meets the second preset condition (ie, the first temperature and the second temperature meet T1-T2≥2°C, or the second temperature meets T2≥25°C), the temperature control switch 5 is in the open state and the drain valve is in the closed state. At this time, the refrigerant needs to flow in the refrigerant main path 21 and the refrigerant branch path 22 at the same time, so that the low-temperature refrigerant that has released the heat can be diverted, so that a part of the refrigerant flows into the refrigerant pipeline of the heat exchange device 3 through the refrigerant main path 21 to exchange heat with the coolant, and after absorbing the heat, it can be merged with the high-temperature refrigerant flowing out of the refrigerant branch path 22 through the refrigerant main path 21, and the other part of the refrigerant flows into the refrigerant flow channel 42 of the liquid cold plate 4 through the refrigerant branch path 22 to absorb the heat generated by the battery pack, and after absorbing the heat, it can flow back to the refrigerant main path 21 through the refrigerant branch path 22 for merging, and the high-temperature refrigerant after merging flows into the heat dissipation component located on the refrigerant main path 21 through the refrigerant main path 21 for heat dissipation, and after releasing the heat, it is diverted again to flow into the heat exchange device 3 and the liquid cold plate 4, so as to continue to absorb the heat of the high-temperature coolant and the heat of the battery pack, thereby realizing intermittent flow of refrigerant in the liquid cold plate 4. At the same time, refrigerant needs to flow in the refrigerant flow channel 42 so that the liquid cooling plate 4 can cool the battery pack through the coolant and refrigerant. Therefore, the drain valve can be controlled to be in a closed state to block the bottom wall of the groove 531 from the external environment or the recovery pipeline, so that the refrigerant can flow stably in the refrigerant flow channel 42 to absorb the heat generated by the battery pack.

[0192] Therefore, the control system in this embodiment can not only control the temperature control switch 5 to switch from the on state to the off state when the battery pack temperature is within the safe temperature range, but also control the temperature control switch 5 to switch from the on state to the off state when the battery cell temperature difference is within the safe temperature range, so that the liquid cooling plate 4 can cool the battery pack alone through the coolant; at the same time, the control system can not only control the temperature control switch 5 to switch from the off state to the on state when the battery pack temperature exceeds the safe temperature range, but also control the temperature control switch 5 to switch from the off state to the on state when the battery cell temperature difference exceeds the safe temperature range, so that the liquid cooling plate 4 can cool the battery pack together through the coolant and the refrigerant.

[0193] Through such a design, the refrigerant can flow into the liquid cooling plate 4 under specific working conditions to achieve continuous flow of the coolant in the liquid cooling plate 4. The refrigerant flows intermittently in the liquid cooling plate 4, which is beneficial to improving the safety of the battery pack in a high-power state or high-temperature environment, and is also beneficial to improving the uniformity of the liquid cooling plate 4 in cooling the battery pack in any working state, thereby reducing the possibility of thermal runaway of the battery pack during the charging and discharging process, and improving the stability and reliability of the energy storage system during operation.

[0194] It should be noted that in the liquid inlet and discharge control method of this embodiment, when the driving member 52 of the temperature control switch 5 is a shape memory alloy, the control system only needs to control the opening or closing of the drain valve according to the detection results of the first detection member 61 and the second detection member 62, and the valve 51 can open or close automatically under the drive of the shape memory alloy; when the driving member 52 of the temperature control switch 5 is a driving mechanism with a power module, the control system needs to synchronously control the working status of the driving member 52 and the drain valve according to the detection results of the first detection member 61 and the second detection member 62.

[0195] Specifically, when the driving member 52 is a shape memory alloy, the second detection member 62 is disposed adjacent to the shape memory alloy along the length and width of the liquid cooling plate 4. This design allows the driving member 52 and the drain valve to move synchronously, i.e., while the driving member 52 is deforming, the control system can control the drain valve to switch from an open state to a closed state, thereby avoiding the risk of leakage of the drain valve during the flow of refrigerant into the refrigerant flow channel 42. Alternatively, while the driving member 52 is deforming, the control system can control the drain valve to switch from a closed state to an open state, thereby promptly discharging the refrigerant remaining in the groove 531 and reducing the possibility of the residual refrigerant affecting the operating performance of the liquid cooling plate 4.

[0196] The above describes in detail the structure, features and effects of the present application based on the embodiments shown in the drawings. The above is only a preferred embodiment of the present application, but the present application does not limit the scope of implementation to what is shown in the drawings. Any changes made in accordance with the concept of the present application, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the description and drawings, should be within the scope of protection of the present application.

Claims

1. An energy storage system, characterized in that: The energy storage system comprises: Coolant circuit; A refrigerant circuit, the refrigerant circuit comprising a refrigerant main circuit and a refrigerant branch circuit; a heat exchange device, the heat exchange device comprising a coolant pipeline and a refrigerant pipeline, the heat exchange device being in communication with the coolant circuit via the coolant pipeline, and the heat exchange device being in communication with the refrigerant main circuit via the refrigerant pipeline; a liquid cooling plate, the liquid cooling plate comprising a cooling liquid flow channel and a refrigerant flow channel, the liquid cooling plate being in communication with the cooling liquid circuit through the cooling liquid flow channel, and the liquid cooling plate being in communication with the refrigerant branch through the refrigerant flow channel; a battery pack, the battery pack being bonded to the liquid cooling plate; The first temperature of the battery pack at the coolant flow channel inlet is T1, the second temperature of the battery pack at the coolant flow channel outlet is T2, and the refrigerant flow channel inlet is further provided with a temperature control switch; When T1 and T2 satisfy T1-T2<2℃, or T2 satisfies T2<25℃, the temperature control switch is in the closed state, and the liquid cooling plate cools the battery pack with coolant; When T1 and T2 satisfy T1-T2≥2°C, or T2 satisfies T2≥25°C, the temperature control switch is in the on state, and the liquid cooling plate cools the battery pack through the coolant and the refrigerant.

2. The energy storage system according to claim 1, characterized in that The temperature control switch includes a valve and a driving member, wherein the valve is installed in the refrigerant flow channel and is rotatably connected to the refrigerant flow channel, and the driving member is fixedly connected to the valve and is used to drive the valve to rotate relative to the refrigerant flow channel to open or close the liquid inlet of the refrigerant flow channel; The valve further includes a first door plate and a second door plate connected to each other. The first door plate has a through hole and is located on a side of the second door plate away from the refrigerant flow channel liquid inlet, and has a first angle between the first door plate and the second door plate.

3. The energy storage system according to claim 2, characterized in that: The driving member is a shape memory alloy, and along the thickness direction of the liquid cooling plate, one end of the shape memory alloy is connected to the first door panel, and the other end of the shape memory alloy is connected to the top wall of the refrigerant flow channel; When T1 and T2 satisfy T1-T2≥2°C, or T2 satisfies T2≥25°C, the shape memory alloy can contract and drive the first door panel to move along a first direction x to open the liquid inlet of the refrigerant flow channel, and the first direction x is opposite to the flow direction of the refrigerant; When T1 and T2 satisfy T1-T2<2℃, or T2 satisfies T2<25℃, the shape memory alloy can return to its initial state and drive the first door panel to move along the second direction y to close the liquid inlet of the refrigerant flow channel, and the second direction y is the same as the flow direction of the refrigerant.

4. The energy storage system according to claim 2, characterized in that: The refrigerant flow channel is also provided with a groove, and the temperature control switch also includes a guide column and an elastic member. The guide column is arranged on the bottom wall of the groove, and the elastic member is sleeved on the outer wall of the guide column, and one end of the elastic member is connected to the bottom wall of the groove, and the other end of the elastic member is connected to the first door panel.

5. The energy storage system according to claim 4, characterized in that: The energy storage system further includes a drain valve, which is mounted on the bottom wall of the groove; When T1 and T2 satisfy T1-T2<2°C, or T2 satisfies T2<25°C, the drain valve is in an open state to discharge the refrigerant in the groove; When T1 and T2 satisfy T1-T2≥2°C, or T2 satisfies T2≥25°C, the drain valve is in a closed state to prevent the refrigerant in the groove from being discharged.

6. The energy storage system according to claim 5, characterized in that: The energy storage system also includes a control system and a detection device. The control system is electrically connected or signal-connected to the detection device, and is electrically connected or signal-connected to the drain valve and / or the drive member. The detection device is installed on the side of the liquid cooling plate facing the battery pack and is used to detect the temperature of the battery pack. The control system is used to control the start or stop of the drive member and / or control the opening or closing of the drain valve based on the detection results of the detection device.

7. The energy storage system according to any one of claims 1 to 6, characterized in that: The liquid cooling plate comprises at least two cooling liquid flow channels and at least one refrigerant flow channel, and the cooling liquid flow channels and the refrigerant flow channels are alternately arranged and spaced apart along the length direction and / or width direction of the liquid cooling plate; The liquid inlet of the cooling liquid flow channel is arranged adjacent to the liquid outlet of the refrigerant flow channel, and the liquid outlet of the cooling liquid flow channel is arranged adjacent to the liquid inlet of the refrigerant flow channel.

8. The energy storage system according to claim 7, characterized in that: Along the length direction and / or width direction of the liquid cooling plate, the two cooling liquid flow channels are symmetrically distributed relative to the refrigerant flow channel, and the spacing between adjacent flow channels is L, and L satisfies 25mm≤L≤45mm.

9. The energy storage system according to any one of claims 1 to 6, characterized in that: Along the thickness direction of the liquid cooling plate, the liquid cooling plate includes a heat exchange plate and a flow channel plate. One side of the heat exchange plate is attached to the battery pack, and the other side of the heat exchange plate is connected to the flow channel plate to enclose the coolant flow channel and the refrigerant flow channel.

10. The energy storage system according to any one of claims 1 to 6, characterized in that: The energy storage system also includes a compressor, a heat sink and an expansion valve. The compressor, the heat sink and the expansion valve are all arranged in the refrigerant main line. The compressor is connected to the liquid outlet of the refrigerant pipeline, the other end of the compressor is connected to the heat sink, the other end of the heat sink is connected to the expansion valve, and the other end of the expansion valve is connected to the liquid inlet of the refrigerant pipeline.

11. A method for controlling liquid inlet and outlet of an energy storage system, wherein the energy storage system is the energy storage system according to any one of claims 1 to 10, and further comprises a valve and a liquid discharge valve, wherein: The liquid inlet and discharge control method comprises: detecting a first temperature T1 of the battery pack at a liquid inlet of the coolant flow channel; detecting a second temperature T2 of the battery pack at a liquid outlet of the coolant flow channel; When T1 and T2 satisfy T1-T2<2°C, or T2 satisfies T2<25°C, controlling the valve to rotate in a second direction y and controlling the drain valve to open to discharge the refrigerant in the refrigerant flow channel, wherein the second direction y is the same as the flow direction of the refrigerant; When T1 and T2 satisfy T1-T2≥2°C, or T2 satisfies T2≥25°C, the valve is controlled to rotate along a first direction x, and the drain valve is controlled to close to prevent the refrigerant in the refrigerant flow channel from being discharged. The first direction x is opposite to the flow direction of the refrigerant.

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