Energy storage system and liquid feeding and discharging control method thereof

Abstract

The invention relates to the technical field of energy storage, and discloses an energy storage system and a liquid feeding and discharging control method thereof.The energy storage system comprises a cooling liquid loop, a refrigerant loop, a heat exchange device, a liquid cooling plate and a battery pack; the heat exchange device comprises a cooling liquid pipeline communicated with the cooling liquid loop and a refrigerant pipeline communicated with the refrigerant main path, the liquid cooling plate comprises a cooling liquid flow channel communicated with the cooling liquid loop and a refrigerant flow channel communicated with the refrigerant branch path, and the battery pack is attached to the liquid cooling plate. A liquid inlet of the refrigerant flow channel is provided with a temperature control switch, when the temperature of the battery pack meets a first preset condition, the temperature control switch is turned off, and the liquid cooling plate cools the battery pack through the cooling liquid, and when the temperature of the battery pack meets a second preset condition, the temperature control switch is turned on, and the liquid cooling plate cools the battery pack through the cooling liquid and the refrigerant; a refrigerant flows into the liquid cooling plate under a specific working condition, so that the safety of the battery pack is improved, and the operation cost of the energy storage system is reduced.

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] At present, energy storage systems are mainly cooled by air cooling, liquid cooling, or a combination of air cooling and liquid cooling to control the temperature inside the energy storage system within a safe range, thereby ensuring the safety of the energy storage system during operation. When the energy storage system is cooled by liquid cooling, the liquid cooling plate can be bonded to the battery pack to cool it, so that the coolant and / or refrigerant circulating in the liquid cooling plate can take away most of the heat generated by the battery pack during operation through heat exchange, thereby ensuring the working stability of the battery pack and extending its service life.

[0003] In the prior art, if only one of the cooling liquid and the refrigerant flows through the liquid cooling plate, the overall cooling effect of the liquid cooling plate will be reduced. However, if both the cooling liquid and the 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 that the refrigeration effect is reduced when the coolant or refrigerant is circulated alone, and the energy consumption is increased when the coolant and refrigerant are circulated 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 refrigerant main circuit and a refrigerant branch circuit; the heat exchange device includes a coolant pipeline and a refrigerant pipeline, the heat exchange device is connected to the coolant circuit through the coolant pipeline, and the heat exchange device is connected to the refrigerant main circuit through 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 through the coolant flow channel, and the liquid cooling plate is connected to the refrigerant branch circuit through the refrigerant flow channel; the battery pack is bonded to the liquid cooling plate.

[0006] Among them, the liquid inlet of the refrigerant flow channel is also provided with a temperature control switch. When the temperature of the battery pack meets the first preset condition, the temperature control switch is in a closed state, and the liquid cooling plate cools the battery pack through the coolant. When the temperature of the battery pack meets the second preset condition, the temperature control switch is in an open state, and the liquid cooling plate cools the battery pack through the coolant and refrigerant.

[0007] 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 cooling plate has a lower temperature, so that it can absorb more heat, so as to improve the cooling effect of the liquid cooling plate on the battery pack; it is also possible for the liquid cooling plate to cool the battery pack alone through the coolant, or to cool the battery pack together with the coolant and the refrigerant, to ensure that the temperature of the battery pack is always maintained within a safe temperature range, so as to improve the stability and reliability of the energy storage system during operation.

[0008] At the same time, the refrigerant can flow into the liquid cooling 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 cooling plate. The intermittent flow of the refrigerant in the liquid cooling plate is beneficial to improve the safety of the battery pack in a high-power state or high-temperature environment, reduce the difficulty of controlling the phase, pressure and temperature of the refrigerant in the liquid cooling plate, and reduce the operating cost and maintenance cost of the energy storage system.

[0009] In a 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.

[0010] 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 liquid inlet, and has a first angle with the second door plate.

[0011] In a possible implementation, 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.

[0012] When the temperature of the battery pack meets the second preset condition, the shape memory alloy can shrink and drive the first door panel to move along the first direction to open the liquid inlet of the refrigerant flow channel.

[0013] 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 to move in the second direction to close the liquid inlet of the refrigerant flow channel.

[0014] The first direction is opposite to the second direction.

[0015] In a possible implementation, the refrigerant flow channel is further provided with a groove, and the temperature control switch further includes a guide post and an elastic member. The guide post is disposed on the bottom wall of the groove, the elastic member is sleeved on the outer wall of the guide post, 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.

[0016] In a possible implementation, the energy storage system further includes a drain valve, and the drain valve is installed on the bottom wall of the groove.

[0017] When the temperature of the battery pack meets the first preset condition, the drain valve is in an open state to discharge the refrigerant in the groove.

[0018] When the temperature of the battery pack meets the second preset condition, the drain valve is in a closed state to block the discharge of the refrigerant in the groove.

[0019] In a possible implementation, the energy storage system further 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 driving member. The detection device is installed on the side of the liquid cooling plate facing the battery pack for detecting the temperature of the battery pack. The control system is used to control the driving member to start or stop according to the detection result of the detection device, and / or control the drain valve to open or close.

[0020] In a possible implementation, the liquid cooling plate includes at least two coolant flow channels and at least one refrigerant flow channel. Along the length direction and / or width direction of the liquid cooling plate, the coolant flow channels and the refrigerant flow channels are alternately arranged and spaced apart.

[0021] Wherein, the liquid inlet of the coolant flow channel is adjacent to the liquid outlet of the refrigerant flow channel, and the liquid outlet of the coolant flow channel is adjacent to the liquid inlet of the refrigerant flow channel.

[0022] In a possible implementation, along the length direction and / or width direction of the liquid cooling plate, the two coolant flow channels are symmetrically distributed with respect to the refrigerant flow channel, and the distance between adjacent channels is L, and L satisfies 25 mm ≤ L ≤ 45 mm.

[0023] In a possible implementation, 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.

[0024] In a possible implementation, the energy storage system further includes a compressor, a heat dissipation device and an expansion valve. The compressor, the heat dissipation device and the expansion valve are all disposed on the refrigerant main path. The compressor is communicated with the liquid outlet of the refrigerant pipeline, the other end of the compressor is communicated with the heat dissipation device, the other end of the heat dissipation device is communicated with the expansion valve, and the other end of the expansion valve is communicated with the liquid inlet of the refrigerant pipeline.

[0025] The present application also provides a method for controlling the liquid inlet and outlet of an energy storage system. The energy storage system includes a liquid cooling plate, a battery pack, a valve, and a drain valve. The liquid cooling plate includes a coolant flow channel and a refrigerant flow channel. The method for controlling the liquid inlet and outlet includes: 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 the first temperature and the second temperature satisfy T1 - T2 < 2°C, or when the second temperature satisfies T2 < 25°C, controlling the valve to rotate along the second direction y and controlling the drain valve to open to discharge the refrigerant in the refrigerant flow channel; when the first temperature and the second temperature satisfy T1 - T2 ≥ 2°C, or when the second temperature satisfies T2 ≥ 25°C, controlling the valve to rotate along the first direction x and controlling the drain valve to close to block the discharge of the refrigerant in the refrigerant flow channel.

[0026] 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 temperature of the battery pack 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 temperature difference between the battery cells 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 temperature of the battery pack exceeds the safe temperature range, but also control the temperature control switch to switch from the off state to the on state when the temperature difference between the battery cells exceeds the safe temperature difference range, so that the liquid cooling plate can cool the battery pack jointly through the coolant and the refrigerant.

[0027] Through such a design method, the refrigerant can flow into the liquid cooling plate under specific working conditions to achieve continuous flow of the coolant in the liquid cooling plate and intermittent flow of the refrigerant in the liquid cooling plate, which is not only beneficial to improving the safety of the battery pack in a high-power state or a high-temperature environment, but also beneficial to improving the uniformity of the liquid cooling plate in cooling the battery pack in any working state, thereby being beneficial to 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.

[0028] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1It is the schematic diagram of the energy storage system provided by this application; Figure 2 It is the top view of the liquid cooling plate provided by this application in an embodiment; Figure 3 It is the structural schematic diagram of the temperature control switch provided by this application in an embodiment; Figure 4 It is the structural schematic diagram of the liquid cooling plate and the temperature control switch; Figure 5 It is the cross-sectional view of the temperature control switch in the closed state; Figure 6 It is the cross-sectional view of the temperature control switch in the open state.

[0031] Explanation of reference numerals: 1 - Coolant circuit; 2 - Refrigerant circuit; 21 - Main refrigerant path; 22 - Refrigerant branch; 3 - Heat exchange device; 4 - Liquid cooling plate; 41 - Coolant flow channel; 411 - Coolant inlet; 412 - Coolant outlet; 42 - Refrigerant flow channel; 421 - Refrigerant inlet; 422 - Refrigerant outlet; 43 - Heat exchange plate; 44 - Flow channel plate; 5 - Temperature control switch; 51 - Valve; 511 - First door panel; 511a - Through hole; 512 - Second door panel; 513 - Rotating shaft; 52 - Driving part; 521 - Temperature sensing section; 522 - Connecting section; 53 - Connecting frame; 531 - Groove; 532 - Elastic part; 6 - Detection device; 61 - First detection part; 62 - Second detection part; 7 - Compressor; 8 - Heat dissipation device; 9 - Expansion valve.

[0032] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. Detailed Description of the Invention

[0033] To better understand the technical solution of the present application, the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0034] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope of protection of the present application.

[0035] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "the", and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0036] It should be understood that the term " / and" used herein is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0037] The embodiments of the present application provide an energy storage system, as Figure 1 and Figure 2 shown, the energy storage system includes a coolant circuit 1, a refrigerant circuit 2, a heat exchange device 3, a liquid cooling plate 4, and a battery pack (not marked in the figure). The refrigerant circuit 2 includes a refrigerant main path 21 and a refrigerant branch path 22; the heat exchange device 3 includes a coolant pipeline (not marked in the figure) and a refrigerant pipeline (not marked in the figure). The heat exchange device 3 is connected to the coolant circuit 1 through the coolant pipeline and is connected to the refrigerant main path 21 through the refrigerant pipeline; 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 through the coolant flow channel 41, and the liquid cooling plate 4 is connected to the refrigerant branch path 22 through the refrigerant flow channel 42; the battery pack is attached to the liquid cooling plate 4.

[0038] Wherein, a temperature control switch 5 is further provided at the liquid inlet of the refrigerant flow channel 42. When the temperature of the battery pack meets the first preset condition, the temperature control switch 5 is in the closed state, and the liquid cooling plate 4 cools down the battery pack through the coolant. When the temperature of the battery pack meets the second preset condition, the temperature control switch 5 is in the open state, and the liquid cooling plate 4 cools down the battery pack through the coolant and the refrigerant.

[0039] In the embodiments of the present application, a plurality of battery packs are included in the energy storage system, and each battery pack is formed by connecting a plurality of battery cells in series / parallel. Since heat is generated during the charge and discharge process of the battery cells, causing the temperature of the battery pack to rise, it is necessary to cool down the battery pack to control the temperature of the battery cells, avoid the risk of performance degradation, reduced lifespan or thermal runaway due to excessive temperature, so as to improve the safety of the battery cells during the charge and discharge process, thereby facilitating the improvement of the stability and reliability of the energy storage system during operation.

[0040] For this reason, in the energy storage system provided in this embodiment, the battery pack is installed on the liquid cooling plate 4 and is attached to the surface of the liquid cooling plate 4. The coolant circuit 1 is used for circulating coolant, and the refrigerant circuit 2 is used for circulating refrigerant. The two are arranged in parallel and are both connected to the liquid cooling plate 4, so that the energy storage system cools down the battery pack by means of liquid cooling.

[0041] Among them, the refrigerant circuit 2 further includes a refrigerant main path 21 and a refrigerant branch path 22 arranged in parallel. The heat exchange device 3 further includes a coolant pipeline and a refrigerant pipeline. The coolant pipeline is connected to the coolant circuit 1, the refrigerant pipeline is connected to the refrigerant main path 21, the liquid cooling plate 4 further 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 path 22. The energy storage system further includes a temperature control switch 5, and the temperature control switch 5 can be arranged at the connection of the refrigerant main path 21 and the refrigerant branch path 22 to control the connection or disconnection between the refrigerant main path 21 and the refrigerant branch path 22.

[0042] Through such a design method, it can enable the coolant circuit 1 and the refrigerant circuit 2 to exchange heat through the heat exchange device 3, so as to ensure that the coolant flowing into the liquid cooling plate 4 has a lower temperature, enabling it to absorb more heat, so as to improve the cooling effect of the liquid cooling plate 4 on the battery pack; it can also enable the liquid cooling plate 4 to cool down the battery pack separately through the coolant, or cool down the battery pack jointly through the coolant and the refrigerant, so as to ensure that the temperature of the battery pack always remains within a safe temperature range, so as to improve the stability and reliability of the energy storage system during operation.

[0043] Meanwhile, since the battery pack has temperature changes during the charging and discharging process, if the coolant is allowed to flow separately 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 dissipate heat quickly, which easily causes 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 flow separately 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 easily affects 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 operation of the energy storage system. If the coolant and the refrigerant are allowed to flow together and continuously in the liquid cooling plate 4, it will cause a significant increase in the operating cost and maintenance cost of the energy storage system.

[0044] Therefore, it is necessary to control the flow 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, in order to improve the safety of the battery pack in a high-power state or a high-temperature environment, and by reducing the proportion of the refrigerant flow channel 42, reduce the control difficulty of the phase state, pressure and temperature of the refrigerant in the liquid cooling plate 4, and also reduce the operating cost and maintenance cost of the energy storage system.

[0045] For this purpose, in the energy storage system provided in this embodiment, the energy storage system can realize the flow or blockage of the refrigerant in the liquid cooling plate 4 through the working state of the temperature control switch 5.

[0046] Among them, the temperature control switch 5 can be set 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 temperature of the battery pack meets the first preset condition (that is, when the battery pack is in a medium-low power state or the ambient temperature is moderate), the temperature control switch 5 is in the closed state, so that the liquid cooling plate 4 cools down the battery pack through the coolant. When the temperature of the battery pack meets the second preset condition (that is, when the battery pack is in a high-power state or the ambient temperature is high), the temperature control switch 5 is in the open state, so that the liquid cooling plate 4 cools down the battery pack through the coolant and the refrigerant.

[0047] 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 of the coolant flow channel 41 of the liquid cooling plate 4 and enter the coolant pipeline of the heat exchange device 3 through the coolant circuit 1 to exchange heat with the refrigerant, and 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 to absorb the heat generated by the battery pack, thereby realizing the continuous flow of the coolant in the liquid cooling plate 4.

[0048] 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 main refrigerant path 21, so that the high-temperature refrigerant that has absorbed the heat of the coolant can flow into the heat dissipation component located on the main refrigerant path 21 through the main refrigerant path 21 for heat dissipation, and after releasing the heat, it can flow back into the refrigerant pipeline of the heat exchange device 3 through the main refrigerant path 21 to exchange heat with the coolant, so as to continue to absorb the heat of the high-temperature coolant.

[0049] When the temperature of the battery pack meets the second preset condition, the temperature control switch 5 is in the open state, and the refrigerant needs to flow in both the main refrigerant 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 shunted. As a result, a part of the refrigerant flows into the refrigerant pipeline of the heat exchange device 3 through the main refrigerant path 21 to exchange heat with the coolant, and after absorbing the heat, it can converge with the high-temperature refrigerant flowing out of the main refrigerant path 21 and the refrigerant branch path 22. Another part of the refrigerant flows into the refrigerant flow channel 42 of the liquid cooling 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 into the main refrigerant path 21 through the refrigerant branch path 22 for convergence. The converged high-temperature refrigerant flows into the heat dissipation component located on the main refrigerant path 21 through the main refrigerant path 21 for heat dissipation, and after releasing the heat, it is shunted again and flows into the heat exchange device 3 and the liquid cooling plate 4, so as to continue to absorb the heat of the high-temperature coolant and the heat of the battery pack, thereby realizing the intermittent flow of the refrigerant in the liquid cooling plate 4.

[0050] Through such a design method, 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 another part of the refrigerant can jointly absorb the heat of the battery pack with the coolant. Furthermore, 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 can be realized, which is beneficial to improving the safety of the battery pack in a high-power state or a high-temperature environment, reducing the control difficulty of the phase state, pressure and temperature of the refrigerant in the liquid cooling plate 4, and reducing the operation cost and maintenance cost of the energy storage system.

[0051] 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 a sensor, a control system, a driving mechanism and a power supply module, or can 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 in the liquid cooling plate 4 to avoid the risk of mutual influence when the coolant and the refrigerant flow in the liquid cooling plate 4 at the same time.

[0052] In a specific implementation manner, asFigure 4 , Figure 5 and Figure 6 As shown in Figure 4 , Figure 5 and Figure 6 , 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.

[0053] In the embodiment of the present application, the heat exchange plate 43 and the flow channel plate 44 can be detachably connected by a seal (such as a sealing strip) and a fastener (such as a bolt), which is convenient for regularly cleaning the flow channels of the flow channel plate 44 (i.e., the coolant flow channel 41 and the refrigerant flow channel 42) to avoid the possibility of the working performance of the liquid cooling plate 4 being reduced due to flow channel blockage. And when the heat exchange plate 43 and / or the flow channel plate 44 are damaged, only the corresponding damaged parts need to be replaced, without replacing the liquid cooling plate 4, which is beneficial to reducing the maintenance cost.

[0054] 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 performance 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.

[0055] Through such a design method, 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 is beneficial to reducing the overall processing difficulty of the liquid cooling plate 4 and better meeting the actual processing requirements.

[0056] In a specific embodiment, as Figure 1 shown, the energy storage system further includes a compressor 7, a heat dissipation device 8 and an expansion valve 9. The compressor 7, the heat dissipation device 8 and the expansion valve 9 are all arranged on the refrigerant main path 21 to form the above-mentioned heat dissipation assembly for cooling the refrigerant.

[0057] Specifically, the compressor 7 is communicated with the liquid outlet of the refrigerant pipeline, the other end of the compressor 7 is communicated with the heat dissipation device 8, the other end of the heat dissipation device 8 is communicated with the expansion valve 9, and the other end of the expansion valve 9 is communicated with the liquid inlet of the refrigerant pipeline.

[0058] 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 and low-pressure liquid refrigerant flows out of the liquid outlet of the refrigerant pipeline, and the high-temperature and low-pressure liquid refrigerant flows into the compressor 7 through the refrigerant circuit 2 for compression to form a high-temperature and high-pressure gaseous refrigerant. After the high-temperature and 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 and high-pressure liquid refrigerant. After the low-temperature and high-pressure liquid refrigerant flows out of the heat dissipation device 8, it flows through the refrigerant circuit 2 through the expansion valve 9 to be transformed into a low-temperature and low-pressure liquid refrigerant. At this time, the low-temperature and 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.

[0059] 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, and evaporates into a gas and then flows back to the compressor 7.

[0060] Through such a design, the heat dissipation cycle of the refrigerant in the refrigerant main circuit 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.

[0061] 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.

[0062] 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 511 a , and the first door plate 511 is located on a 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 .

[0063] In the embodiment of the present application, the temperature control switch 5 further includes a rotating shaft 513. The valve 51 is rotatably connected to the inner wall of the refrigerant flow channel 42 through the rotating shaft 513, so that the opening or closing of the temperature control switch 5 can be realized by rotating the valve 51 relative to the refrigerant flow channel 42, which is beneficial to improving the response speed and control accuracy of the temperature control switch 5, so that the driving member 52 can control the opening degree of the valve 51 according to the temperature of the battery pack, thereby accurately adjusting the flow rate of the refrigerant flowing into the refrigerant flow channel 42, and further being beneficial to further saving energy and reducing energy consumption. At the same time, the rotatable connection method can also reduce the wear of the valve 51, which is beneficial to improving the service life and sealing reliability of the temperature control switch 5, and can also reduce the number of components required for the temperature control switch 5, which is beneficial to reducing the production cost of the temperature control switch 5.

[0064] 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 rotate relative to the refrigerant flow channel 42 under the action of the driving member 52, and the valve 51 rotates along the second direction y until the first door panel 511 is parallel to the bottom wall of the refrigerant flow channel 42. Since there is a first included angle between the first door panel 511 and the second door panel 512, a second included angle complementary to the first included angle is formed between the second door panel 512 and the bottom wall of the refrigerant flow channel 42, so that the second door panel 512 is perpendicular to the bottom wall of the refrigerant flow channel 42, or is inclined relative to the bottom wall of the refrigerant flow channel 42.

[0065] The second door panel 512 is used to block the refrigerant branch 22 and the refrigerant flow channel 42, so as to block 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 through the coolant to meet the cooling requirements of the battery pack in a high-power state or a high-temperature environment, so that the energy storage system can operate with low energy consumption, which is beneficial to saving energy and reducing the operating cost.

[0066] 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 rotates along the first direction x until the second door panel 512 is parallel to the bottom wall of the refrigerant flow channel 42. Since there is a first included angle between the first door panel 511 and the second door panel 512, and the first door panel 511 has a through hole 511a, the first door panel 511 is perpendicular to the bottom wall of the refrigerant flow channel 42, or is inclined relative to the bottom wall of the refrigerant flow channel 42.

[0067] 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, enabling the liquid cooling plate 4 to cool the battery pack jointly with 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 improving the safety of the battery pack during charging and discharging, and further improving the stability and reliability of the energy storage system during operation.

[0068] In a specific embodiment, the first door panel 511 and the second door panel 512 are of an integrally formed structure.

[0069] In a specific embodiment, as Figure 5 and Figure 6 shown, the first included angle between the first door panel 511 and the second door panel 512 is α, and α satisfies 120° ≤ α ≤ 150°, and the second included angle complementary to the first included angle is β.

[0070] In the embodiment of the present application, the first included 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.

[0071] When the first included angle between the first door panel 511 and the second door panel 512 is too small (for example, α < 120°), the first included angle between the two can be one of an acute angle, a right angle, and an obtuse angle. When the first included angle is an acute angle or a right angle, during the flow of the refrigerant along the third direction z, there is a possibility that the second door panel 512 deforms under the impact of the refrigerant, making it easy to generate a gap between the second door panel 512 and the top wall of the refrigerant flow channel 42, so that the refrigerant can flow into the refrigerant flow channel 42 through this gap, resulting in a risk of leakage when the temperature control switch 5 is in the closed state. When the first included angle is an obtuse angle with a relatively small degree, the degree of the second included angle complementary to it will be relatively large, resulting in a relatively long rotation stroke of the valve 51 when the temperature control switch 5 changes from the closed state to the open state.

[0072] When the first included 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 restricted by the internal space of the refrigerant flow channel 42. If the first included angle between them is too large, it is likely to cause the size of the first door panel 511 and / or the second door panel 512 in the third direction z to become larger, so that the driving member 52 needs to provide a greater driving force to drive the valve 51 to rotate.

[0073] When the first included angle between the first door panel 511 and the second door panel 512 satisfies 120° ≤ α ≤ 150°, the first included angle between them is an obtuse angle, and the sizes of the first door panel 511 and the second door panel 512 in the third direction z are appropriate.

[0074] When the temperature control switch 5 is in the closed state, the second door panel 512 is inclined relative to the bottom wall of the refrigerant flow channel 42 and abuts against the top wall of the refrigerant flow channel 42. And during the process of the refrigerant flowing in the third direction z, the refrigerant continuously impacts the second door panel 512 and makes it rotate in 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 acting force between it and the top wall of the refrigerant flow channel 42 under the impact of the refrigerant, so as to effectively block the flow of the refrigerant in the third direction z, and further improve the sealing performance of the temperature control switch 5 in the closed state.

[0075] When the temperature control switch 5 switches from the closed state to the open state, the driving member 52 only needs to drive the valve 51 to rotate 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, so that the refrigerant can flow into the refrigerant flow channel 42 through this gap, which is beneficial to reducing the control difficulty of the temperature control switch 5 during the process of changing the working state. At the same time, the degree of the second included angle complementary to the first included angle is small, so that the rotation stroke of the valve 51 is short, so that the temperature control switch 5 can easily change its working state.

[0076] Therefore, by setting the first included angle between the first door panel 511 and the second door panel 512 as an obtuse angle satisfying 120° ≤ α ≤ 150°, the possibility of the valve 51 rotating randomly under the impact of the refrigerant can be reduced to improve the sealing performance of the temperature control switch 5 in the closed state, and the control difficulty of the temperature control switch 5 during the process of changing the working state can also be reduced, so as to ensure the stability and reliability of the energy storage system during operation.

[0077] 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.

[0078] In the embodiment of the present application, by providing a seal, the second door panel 512 can be hermetically connected to the inner wall of the refrigerant flow channel 42, so as to improve the sealing performance between the two, and further reduce the possibility of refrigerant flowing into the refrigerant flow channel 42 when the temperature control switch 5 is in the closed state.

[0079] Specifically, a receiving groove for receiving the seal can be provided on the side wall of the second door panel 512, so as to reduce the possibility of the seal being disengaged 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.

[0080] More specifically, the projection of the seal along the third direction z can be one of a C shape, a U shape or an O shape, so that while the second door panel 512 abuts against the top wall of the refrigerant flow channel 42 through the seal, it can also abut against the side wall of the refrigerant flow channel 42 through the seal, and 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 hermetic connection between the second door panel 512 and the inner wall of the refrigerant flow channel 42.

[0081] It should be noted that when the second door panel 512 is hermetically connected to the inner wall of the refrigerant flow channel 42 through the seal, during the process of the temperature control switch 5 changing its working state, the force applied by the driving member 52 to the valve 51 will increase accordingly to overcome the friction force between the seal and the inner wall of the refrigerant flow channel 42, so as to ensure that the valve 51 can rotate smoothly along the first direction x or the second direction y, thereby ensuring the flexibility and reliability of the temperature control switch 5.

[0082] In a specific embodiment, as Figure 3 、 Figure 4 、 Figure 5 and Figure 6 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.

[0083] Wherein, when the temperature of the battery pack meets the second preset condition, the shape memory alloy can contract 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, and the first direction x is opposite to the second direction y.

[0084] In the embodiment of the present application, when the driving member 52 is a shape memory alloy, the driving member 52 can drive the valve 51 to rotate along the first direction x or the second direction y according to the temperature of the battery pack through its own characteristics, so as to be able to control the temperature control switch 5 to switch between the closed state and the open state. Furthermore, the temperature control switch 5 can autonomously change its working state according to the temperature of the battery pack, which is beneficial to improving the sensitivity of the temperature control switch 5. There is no need to control it through signals of components such as sensors and control systems, making it have a faster response speed to ensure the safety and service life of the battery pack. At the same time, through such a design method, it is also possible to reduce 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 to simplifying the overall complexity and energy consumption of the energy storage system, thereby reducing the operating cost of the energy storage system. In addition, the shape memory alloy has good stability during the deformation process, and also has good corrosion resistance and a long service life, so that the driving member 52 will not have the situation of easy wear of mechanical components during the movement process, which is beneficial to ensuring the stability and reliability of the driving member 52 during the working process, and thus can significantly extend the service life of the temperature control switch 5.

[0085] Specifically, since the shape memory alloy is 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.

[0086] 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 an 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 returning 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).

[0087] Wherein, 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 one end of the first door panel 511 away from the second door panel 512.

[0088] When the temperature-sensing section 521 senses that the temperature of the battery pack does not exceed the safe temperature range (i.e., when the temperature of the battery pack meets the first preset condition), the shape memory alloy as a whole can maintain the initial preset shape (i.e., the preset shape in the low-temperature phase) to limit the rotation of the first door panel 511 along the first direction x, thereby ensuring the sealing performance of the temperature control switch 5 in the closed state.

[0089] 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 overall shape memory alloy can deform while the temperature of the battery pack exceeds the safe temperature range and maintain the preset shape after deformation (i.e., the preset shape in the high-temperature phase), so as to be able to pull the first door panel 511 to rotate along the first direction x, and further enable the temperature control switch 5 to change from the closed state to the open state in a timely manner, so that the refrigerant can flow into the refrigerant flow channel 42 through the first through hole 511a of the first door panel 511, and the liquid cooling plate 4 cools down the battery pack through the coolant and the refrigerant.

[0090] At the same time, when the temperature sensing section 521 senses that the temperature of the battery pack drops to within the safe temperature range, the overall shape memory alloy can return to the initial preset shape (i.e., the preset shape in the low-temperature phase) while the temperature of the battery pack drops back to the safe temperature range, so as to be able to drive the first door panel 511 to rotate along the second direction y, and further enable the temperature control switch 5 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, and the liquid cooling plate 4 cools down the battery pack through the coolant alone.

[0091] In a specific embodiment, a cavity (not marked in the figure) for accommodating the temperature sensing section 521 is provided on the top wall of the refrigerant flow channel 42, so that the temperature sensing section 521 of the shape memory alloy is connected to the top wall of the refrigerant flow channel 42 in a limited way, so as to ensure 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 connecting section 522 of the shape memory alloy during the deformation process.

[0092] In a specific embodiment, when the driving member 52 is a shape memory alloy, the material of the driving member 52 can be nickel-titanium alloy, such as Ni50Ti48Zr2, so that the phase change temperature of the driving member 52 is 25°C. Among them, shape memory alloys with different phase change temperatures can also be obtained by changing the ratio between different elements in the material and / or adding or subtracting elements.

[0093] In a specific embodiment, the temperature sensing section 521 and the connecting section 522 are an integrally formed structure.

[0094] In a specific embodiment, as Figure 3 and Figure 4 shown, the refrigerant flow channel 42 is further provided with a groove 531, the temperature control switch 5 further includes a guide post (not marked in the figure) and an elastic member 532, the guide post is arranged on the bottom wall of the groove 531, the elastic member 532 is sleeved on the outer wall of the guide post, 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.

[0095] In the embodiment of the present application, the groove 531 is used to accommodate the guide post and the elastic member 532. The elastic member 532 can elastically deform and is used to provide a pulling force to the first door panel 511, so that the first door panel 511 can be parallel to the bottom wall of the refrigerant flow channel 42, thereby improving the sealing performance of the temperature control switch 5 in the closed state, and promoting the rotation of the valve 51 in the second direction y during the process of changing from the open state to the closed state, so as to improve the smoothness of the reset of the valve 51. The guide post can limit the deformation direction of the elastic member 532 during the deformation process, avoiding situations such as dislocation of the elastic member 532 during elastic deformation, so that the elastic member 532 can be smoothly reset.

[0096] 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 change 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, so that the first door panel 511 can be parallel to the bottom wall of the refrigerant flow channel 42, and the second door panel 512 can be inclined to the bottom wall of the refrigerant flow channel 42. Furthermore, the temperature control switch 5 can be kept in the closed state to block the liquid inlet of the refrigerant flow channel 42 and prevent the refrigerant from flowing in.

[0097] 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. The shape memory alloy can pull the first door panel 511 to rotate in the first direction x, so that the first door panel 511 can be inclined 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. Furthermore, the temperature control switch 5 can be in the open state to open the liquid inlet of the refrigerant flow channel 42, so that the refrigerant can flow in.

[0098] Specifically, when the temperature sensing section 521 senses that the temperature of the battery pack drops back to 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 change 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 in the second direction y, so that the first door panel 511 is restored to be parallel to the bottom wall of the refrigerant flow channel 42, and the second door panel 512 is restored to be inclined to the bottom wall of the refrigerant flow channel 42. Furthermore, the temperature control switch 5 can be restored to the closed state to re-block the liquid inlet of the refrigerant flow channel 42 and prevent the refrigerant from flowing in.

[0099] In a specific embodiment, the temperature control switch 5 further includes a connecting frame 53, and the valve 51, the rotating shaft 513, the driving member 52, the groove 531, the guiding column, and the elastic member 532 can all be disposed 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 the liquid inlet of the refrigerant flow channel 42.

[0100] In a specific embodiment, the connecting frame 53 is detachably connected to the refrigerant flow channel 42 of the liquid cooling plate 4. So when the temperature control switch 5 fails, it is not necessary to replace the liquid cooling plate 4 as a whole. Only by detaching the connecting frame 53 from the liquid cooling plate 4 can the replacement or maintenance of components such as the valve 51 and the rotating shaft 513 be realized, which is beneficial to improving the maintenance efficiency and reducing the maintenance cost. And through such a design method, it is also beneficial to improve the versatility of the temperature control switch 5, enabling it to be installed at the inlet and outlet of any flow channel of the liquid cooling plate 4 to meet the other requirements of the liquid cooling plate 4 and the energy storage system.

[0101] 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, the guiding column may not be provided in the groove 531 to further simplify the structure of the temperature control switch 5.

[0102] In a specific embodiment, the energy storage system further includes a drain valve (not marked in the figure), and the drain valve is installed on the bottom wall of the groove 531. When the temperature of the battery pack meets the first preset condition, the drain valve is in an open state to drain the refrigerant in the groove 531. When the temperature of the battery pack meets the second preset condition, the drain valve is in a closed state to block the refrigerant in the groove 531 from being discharged.

[0103] In the embodiment of the present application, since the groove 531 is provided at the liquid inlet of the refrigerant flow channel 42 (or the connecting frame 53), when the temperature control switch 5 is in an open state, the refrigerant will flow in the refrigerant flow channel 42, so that part of the refrigerant will flow into the groove 531 and still remain in the groove 531 after the temperature control switch 5 turns to the closed state. If there is too much residual refrigerant in the groove 531, there is a possibility that the residual refrigerant will affect the normal operation of the temperature control switch 5 (for example, when the ambient temperature is too low, the refrigerant in the groove 531 may freeze, resulting in the valve 51 being unable to rotate). Therefore, it is necessary to drain the residual refrigerant in the groove 531 to ensure the stability and reliability of the temperature control switch 5 during operation.

[0104] 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, there is no need for refrigerant to flow in the refrigerant flow channel 42, so that the liquid cooling plate 4 can cool down 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.

[0105] Among them, if the sealing performance of the temperature control switch 5 decreases and part of the refrigerant penetrates into the refrigerant flow channel 42, it can also be discharged through the drain valve in the groove 531 for recycling.

[0106] 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 down the battery pack jointly through the coolant and the refrigerant. Therefore, the drain valve can be controlled to be in the 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.

[0107] Through such a design method, the working states of the valve 51 and the drain valve can be made opposite. When the valve 51 connects the refrigerant branch 22 and the refrigerant flow channel 42, the closed drain valve can form a sealed refrigerant flow channel 42, thus avoiding the risk of refrigerant leakage during the flow process, which is beneficial to reducing the loss of refrigerant, ensuring the pressure stability during the refrigerant flow, and further ensuring the working performance of the liquid cooling plate 4 in cooling down the battery pack. When the valve 51 blocks the refrigerant branch 22 and the refrigerant flow channel 42, the open drain valve can form an open refrigerant flow channel 42, thus actively discharging the residual refrigerant in the refrigerant flow channel 42 and reducing the pressure in the refrigerant flow channel 42, and further reducing the impact of the residual refrigerant on the sealing performance of the valve 51. At the same time, during the operation of the energy storage system, discharging the residual refrigerant from the refrigerant flow channel 42 in time can also avoid the risk of corrosion or impurity deposition in the refrigerant flow channel 42 caused by the overlong residence time of the residual refrigerant, thus ensuring the stability and reliability of the operation of the energy storage system.

[0108] It should be noted that the drain valve located at the bottom wall of the groove 531 can change its working state according to a preset program through a sensor, a control system, a driving mechanism and a power supply module, or can also be manually controlled by an operator according to the amount of residual refrigerant in the groove 531.

[0109] In a specific embodiment, both the valve 51 and the drain valve can change their working states according to a preset program through sensors, a control system, a driving mechanism, and a power supply module, so that the two cooperate with each other, which is beneficial to improving the flexibility of the liquid cooling plate 4 when switching working states.

[0110] 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 semi-circular.

[0111] In the embodiment of the present application, through such a design method, the refrigerant in the groove 531 can be concentrated 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, ensuring that as much of the residual refrigerant in the groove 531 as possible is discharged, and reducing the possibility of refrigerant remaining in the groove 531.

[0112] In a specific embodiment, the volume of the groove 531 is V, and V satisfies 1 ml ≤ V ≤ 10 ml.

[0113] In the embodiment of the present application, the volume V of the groove 531 can specifically be 1 ml, 1.2 ml, 1.4 ml, 1.6 ml, 1.8 ml, 2 ml, 2.2 ml, 2.4 ml, 2.6 ml, 2.8 ml, 3 ml, 3.2 ml, 3.4 ml, 3.6 ml, 3.8 ml, 4 ml, 4.2 ml, 4.4 ml, 4.6 ml, 4.8 ml, 5 ml, 5.2 ml, 5.4 ml, 5.6 ml, 5.8 ml, 6 ml, 6.2 ml, 6.4 ml, 6.6 ml, 6.8 ml, 7 ml, 7.2 ml, 7.4 ml, 7.6 ml, 7.8 ml, 8 ml, 8.2 ml, 8.4 ml, 8.6 ml, 8.8 ml, 9 ml, 9.2 ml, 9.4 ml, 9.6 ml, 9.8 ml, 10 ml, etc.

[0114] When the volume of the groove 531 satisfies 1 ml ≤ V ≤ 10 ml, while the groove 531 has a sufficient accommodation space for the guide post and the elastic member 532, it can ensure that there is less residual refrigerant in the groove 531, which is beneficial to reducing refrigerant loss, and can reduce the possibility that the residual refrigerant affects 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.

[0115] In a specific embodiment, as Figure 2As shown, the energy storage system further includes a control system (not shown in the figure) and a detection device 6. The control system is electrically connected or signal-connected to the detection device 6, and is electrically connected or signal-connected to the drain valve and / or the driving member 52. The detection device 6 is installed on the side of the liquid cooling plate 4 facing the battery pack for detecting the temperature of the battery pack. The control system is used to control the driving member 52 to start or stop according to the detection result of the detection device 6, and / or control the drain valve to open or close.

[0116] In the embodiment of the present application, when the control system is electrically connected or signal-connected to the driving member 52, the driving member 52 can be a driving mechanism such as a motor. The detection device 6 is used to detect the temperature of the battery pack and transmit the detection result 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 according to the detection result of the detection device 6.

[0117] 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.

[0118] Therefore, the control system can control the temperature control switch 5 to switch from the closed state to the open state while the temperature of the battery pack exceeds the safe temperature range, so that the liquid cooling plate 4 cools the battery pack through the coolant and the refrigerant together, so as to improve the sensitivity and response speed of the driving member 52, thereby improving the safety of the battery pack in a high-power state or a high-temperature environment. The control system can control the temperature control switch 5 to switch from the open state to the closed state while the temperature of the battery pack drops back to the safe temperature range, so that the liquid cooling plate 4 cools the battery pack through the coolant alone, so as to reduce the control difficulty of the control system for the phase state, pressure and temperature of the refrigerant in the liquid cooling plate 4, and reduce the operation cost and maintenance cost of the energy storage system.

[0119] 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 result 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 according to the detection result of the detection device 6.

[0120] 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, so as to connect the bottom wall of the groove 531 with the external environment or the recovery pipeline, so that the residual refrigerant 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, so as 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 and improve the cooling capacity of the liquid cooling plate 4 for the battery pack.

[0121] It should be noted that when the driving member 52 is a shape memory alloy, the control system can be electrically connected or signal-connected to the detection device 6 and the drain valve, so that the shape memory alloy can autonomously change its working state according to the temperature of the battery pack to improve the sensitivity of the driving member 52. As a result, the control system only needs to control the working state of the drain valve according to the signal of the detection device 6, which is beneficial to reducing the complexity and design difficulty of the control system. When the driving member 52 is a driving mechanism such as a motor, the control system can be electrically connected or signal-connected to the detection device 6, the drain valve and the driving member 52 respectively, so that the control system can control the working states of the driving member 52 and the drain valve according to the signal of the detection device 6, which is beneficial to better coordinating their working states and making the cooperation between the valve 51 and the drain valve more compact during the working process.

[0122] In a specific embodiment, as Figure 2 shown, the liquid cooling plate 4 includes at least two coolant flow channels 41 and at least one refrigerant flow channel 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 are alternately arranged and spaced apart.

[0123] Among them, the inlet of the coolant flow channel 41 is adjacent to the outlet of the refrigerant flow channel 42, and the outlet of the coolant flow channel 41 is adjacent to the inlet of the refrigerant flow channel 42.

[0124] In the embodiment of the present application, taking the liquid cooling plate 4 including two coolant flow channels 41 and one refrigerant flow channel 42 as an example, along the length direction and / or width direction of the liquid cooling plate 4, the two coolant flow channels 41 are spaced apart, the refrigerant flow channel 42 is located between the two coolant flow channels 41, and there is at least a partial distance between the refrigerant flow channel 42 and the two coolant flow channels 41, and the three flow channels are in the same plane.

[0125] By alternately arranging the coolant flow channels 41 and the refrigerant flow channels 42 along the length direction and / or the width direction of the liquid cooling plate 4, the distribution of the coolant flow channels 41 and the refrigerant flow channels 42 on the liquid cooling plate 4 can be made more uniform, so as to improve the uniformity of the liquid cooling plate 4 in cooling the battery pack, thereby avoiding the risk of local overheating of the battery pack during charging and discharging, and further being beneficial to improving the safety of the battery pack.

[0126] Among them, since the coolant flow channels 41 and the refrigerant flow channels 42 can be alternately arranged in the same plane of the liquid cooling plate 4, a design scheme 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 the compact layout inside the energy storage system.

[0127] At the same time, by arranging the adjacent flow channels to be spaced apart, it can ensure that the coolant in the coolant flow channels 41 and the refrigerant in the refrigerant flow channels 42 can fully absorb the heat generated by the battery pack, which is beneficial to improving the heat exchange efficiency.

[0128] In addition, by arranging the coolant inlet 411 adjacent to the refrigerant outlet 422 and the coolant outlet 412 adjacent to the refrigerant inlet 421, the coolant flow channels 41 and the refrigerant flow channels 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 the ability to cool down. And by setting the flow directions of the coolant and the refrigerant to be opposite, 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 entire liquid cooling plate 4 and the battery pack, thereby improving the stability and reliability of the energy storage system during operation.

[0129] In a specific embodiment, as Figure 2 shown, along the length direction and / or the width direction of the liquid cooling plate 4, the two coolant flow channels 41 are symmetrically distributed with respect to the refrigerant flow channel 42, and the distance between adjacent flow channels is L, and L satisfies 25 mm ≤ L ≤ 45 mm.

[0130] In the embodiment of the present application, by arranging the two coolant flow channels 41 to be symmetrically distributed with respect to the refrigerant flow channel 42, the distance between each flow channel can be made equal, thereby further improving the uniformity of the distribution of the coolant flow channels 41 and the refrigerant flow channels 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 caused by the asymmetric layout of the flow channels, and further improving the safety and reliability of the battery pack during charging and discharging to ensure the stable operation of the energy storage system.

[0131] Specifically, the spacing L between adjacent flow channels can specifically be 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, etc.

[0132] When the spacing between adjacent flow channels satisfies 25 mm ≤ L ≤ 45 mm, it can ensure that the coolant flow channel 41 and the refrigerant flow channel 42 occupy a relatively large area ratio on the liquid cooling plate 4, while reducing the interaction between adjacent flow channels, so as to ensure that the coolant and the refrigerant can fully absorb the heat generated by the battery pack, thereby improving the heat exchange efficiency with the liquid cooling plate 4.

[0133] 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, and the projected area of the refrigerant flow channel 42 is S2, and S1 and S2 satisfy 0.5 ≤ S2 / S1 ≤ 1.

[0134] 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 specifically 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.

[0135] When the ratio of the projected area between the refrigerant flow channel 42 and the coolant flow channel 41 satisfies 0.5 ≤ S2 / S1 ≤ 1, the area ratio of the coolant 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 coolant flows alone inside it, so that the liquid cooling plate 4 can effectively cool down the battery pack, thereby ensuring the safety and reliability of the battery pack during charging and discharging.

[0136] In a specific embodiment, along the length direction and / or width direction of the liquid cooling plate 4, the number of the coolant flow channels 41 is a, and the number of the refrigerant flow channels 42 is b, and a and b satisfy a - b = 1.

[0137] In a specific embodiment, along the thickness direction of the liquid cooling plate 4, the cross-sectional area of the coolant flow channel 41 for fluid passage is S3, and the cross-sectional area of the refrigerant flow channel 42 for fluid passage is S4, and S3 and S4 satisfy 0.5 ≤ S3 / S4 ≤ 1.

[0138] In the embodiments 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 specifically 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.

[0139] 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 that 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, reduce the pressure drop, ensure that the refrigerant can fully absorb the heat generated by the battery pack, and thus can provide good cooling and temperature reduction capabilities. In the process of the liquid cooling plate 4 cooling and temperature-reducing the battery pack through the coolant and the refrigerant together, it is beneficial to significantly improve the heat exchange efficiency of the liquid cooling plate 4 and improve the uniformity of cooling and temperature reduction of the battery pack, thereby ensuring the safety and reliability of the battery pack during charging and discharging.

[0140] In a specific embodiment, along the thickness direction of the liquid cooling plate 4, the projected shapes of the coolant flow channel 41 and the refrigerant flow channel 42 are both linear structures.

[0141] In the embodiments of the present application, the shapes of the coolant flow channel 41 and the refrigerant flow channel 42 can be linear structures such as straight lines, curves, and winding snake shapes. Through such a design method, the extension lengths of the respective flow channels can be longer, so as to increase the flow time of the coolant and the refrigerant in the respective flow channels, which is beneficial to improving the effective utilization rate of the coolant and the refrigerant. At the same time, along the thickness direction of the liquid cooling plate 4, the projections of the coolant flow channel 41 and the refrigerant flow channel 42 can cover a larger area of the liquid cooling plate 4, which is beneficial to increasing the heat exchange area between the liquid cooling plate 4 and the battery pack, and further improving the cooling and temperature reduction efficiency of the liquid cooling plate 4 for the battery pack and the heat exchange efficiency between the two.

[0142] The embodiments of the present application also provide a method for controlling the inlet and outlet liquid of an energy storage system, as Figure 2 shown. The detection device 6 includes a first detection member 61 and a second detection member 62 that are electrically connected or signal-connected to the control system. Along the thickness direction of the liquid cooling plate 4, both the first detection member 61 and the second detection member 62 are installed on the side of the liquid cooling plate 4 facing the battery pack, and the first detection member 61 is located at the inlet of the coolant flow channel 41, and the second detection member 62 is located at the outlet of the coolant flow channel 41. The method for controlling the inlet and outlet liquid includes: The first detector 61 detects the first temperature T1 of the battery pack at the liquid inlet of the coolant flow channel 41; the second detector 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°C, or when the second temperature satisfies T2 < 25°C, 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°C, or when the second temperature satisfies T2 ≥ 25°C, the control system controls the valve 51 to rotate along the first direction x and controls the drain valve to close to block the discharge of the refrigerant in the groove 531.

[0143] Wherein, when the temperature of the battery pack satisfies the first preset condition, the first preset condition is that the first temperature and the second temperature satisfy T1 - T2 < 2°C, or the second temperature satisfies T2 < 25°C; when the temperature of the battery pack satisfies the second preset condition, the second preset condition is that the first temperature and the second temperature satisfy T1 - T2 ≥ 2°C, or the second temperature satisfies T2 ≥ 25°C.

[0144] In the embodiment of the present application, when the liquid cooling plate 4 cools the battery pack alone through the coolant, since the coolant in the coolant flow channel 41 will flow unidirectionally along its extension direction, the heat absorption capacity of the coolant will gradually decrease as the coolant flows, resulting in a temperature difference between the temperature of the battery cell at the liquid outlet of the coolant flow channel 41 and the temperature of the battery cell at the liquid inlet of the coolant flow channel 41 in the battery pack (that is, there is a difference between the first temperature and the second temperature), which in turn easily leads to a decrease in the cooling uniformity of the liquid cooling plate 4 for the battery pack. And during the charging and discharging process of the battery pack, if the temperature difference between the battery cells in the battery pack is large, it is easy to cause a decrease in the charging and discharging efficiency of the battery pack and an increase in the 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.

[0145] Therefore, it is not only necessary for the control system to control the temperature control switch 5 to change its working state when the temperature of the battery pack exceeds the safe temperature range, but also necessary for the control system to control the temperature control switch 5 to change its working state when the temperature difference between 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, 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.

[0146] Therefore, in the liquid inlet and outlet control method provided in this embodiment, the first preset condition is that T1 and T2 satisfy T1 - T2 < 2°C, or T2 satisfies T2 < 25°C, and the second preset condition is that T1 and T2 satisfy T1 - T2 ≥ 2°C, or T2 satisfies T2 ≥ 25°C, 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 between the battery cells in the battery pack exceeds the safe temperature difference range.

[0147] Among them, the temperature control switch 5 can be arranged 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 temperature of the battery pack satisfies the first preset condition (that is, T1 and T2 satisfy T1 - T2 < 2°C, or T2 satisfies T2 < 25°C), the temperature control switch 5 is in the closed state and the drain valve is in the open state, so that the liquid cooling plate 4 cools the battery pack alone through the coolant. When the temperature of the battery pack satisfies the second preset condition (that is, T1 and T2 satisfy T1 - T2 ≥ 2°C, or T2 satisfies T2 ≥ 25°C), the temperature control switch 5 is in the open state and the drain valve is in the closed state, so that the liquid cooling plate 4 cools the battery pack jointly through the coolant and the refrigerant.

[0148] Specifically, when the temperature of the battery pack satisfies the first preset condition (that is, the first temperature and the second temperature satisfy T1 - T2 < 2°C, or the second temperature satisfies T2 < 25°C), the temperature control switch 5 is in the closed state and the drain valve is in the open state. At this time, 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 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 can flow back into the refrigerant pipeline of the heat exchange device 3 through the refrigerant main path 21 to exchange heat with the coolant, so as to continue to absorb the heat of the high-temperature coolant. At the same time, the refrigerant does not need 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.

[0149] Specifically, when the temperature of the battery pack meets the second preset condition (i.e., the first temperature and the second temperature satisfy T1 - T2 ≥ 2°C, or the second temperature satisfies T2 ≥ 25°C), the temperature control switch 5 is in the on state and the drain valve is in the off state. At this time, the refrigerant needs to flow in both the main refrigerant path 21 and the refrigerant branch path 22 simultaneously, enabling the low-temperature refrigerant that has released heat to be split. As a result, a portion of the refrigerant flows into the refrigerant pipeline of the heat exchange device 3 through the main refrigerant path 21 to exchange heat with the coolant, and after absorbing heat, it can converge with the high-temperature refrigerant flowing out through the main refrigerant path 21 and the refrigerant branch path 22. Another portion of the refrigerant flows into the refrigerant flow channel 42 of the liquid cooling plate 4 through the refrigerant branch path 22 to absorb the heat generated by the battery pack, and after absorbing heat, it can flow back into the main refrigerant path 21 through the refrigerant branch path 22 for convergence. The converged high-temperature refrigerant flows into the heat dissipation component located on the main refrigerant path 21 through the main refrigerant path 21 for heat dissipation, and after releasing heat, it is split again and flows into the heat exchange device 3 and the liquid cooling plate 4 to continue absorbing the heat of the high-temperature coolant and the heat of the battery pack, thereby achieving intermittent flow of the refrigerant in the liquid cooling plate 4. Meanwhile, the refrigerant needs to flow through the refrigerant flow channel 42 so that the liquid cooling plate 4 can cool down the battery pack jointly through the coolant and the refrigerant. Therefore, the drain valve can be controlled to be in the off state to block the bottom wall of the groove 531 from the external environment or the recovery pipeline, enabling the refrigerant to flow stably in the refrigerant flow channel 42 to absorb the heat generated by the battery pack.

[0150] 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 temperature of the battery pack 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 temperature difference between the battery cells is within the safe temperature difference range, so that the liquid cooling plate 4 cools down the battery pack solely through the coolant. Meanwhile, the control system can not only control the temperature control switch 5 to switch from the off state to the on state when the temperature of the battery pack 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 temperature difference between the battery cells exceeds the safe temperature difference range, so that the liquid cooling plate 4 cools down the battery pack jointly through the coolant and the refrigerant.

[0151] Through such a design method, 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 and intermittent flow of the refrigerant in the liquid cooling plate 4. This is not only beneficial to improving the safety of the battery pack in a high-power state or a high-temperature environment, but also conducive to enhancing the uniformity of the liquid cooling plate 4 in cooling down the battery pack in any working state, thereby helping to reduce the possibility of thermal runaway during the charging and discharging process of the battery pack and improving the stability and reliability of the energy storage system during operation.

[0152] It should be noted that in the liquid inlet and outlet 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 be opened or closed 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 supply module, the control system needs to synchronously control the working states 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.

[0153] Specifically, when the driving member 52 is a shape memory alloy, the second detection member 62 is arranged adjacent to the shape memory alloy along the length direction and the width direction of the liquid cooling plate 4. Through this design method, the driving member 52 and the drain valve can move synchronously, that is, when the driving member 52 deforms, the control system can control the drain valve to switch from the open state to the closed state, avoiding the risk of leakage of the drain valve during the flow of the refrigerant into the refrigerant flow channel 42, or when the driving member 52 deforms, the control system can control the drain valve to switch from the closed state to the open state, so as to timely discharge the residual refrigerant in the groove 531 and reduce the possibility of the residual refrigerant affecting the working performance of the liquid cooling plate 4.

[0154] The structure, features and effects of the present application have been described in detail based on the embodiments shown in the drawings. The above is only the preferred embodiment of the present application, but the present application is not limited to the scope defined by the drawings. Any changes made according to the concept of the present application, or modified into equivalent embodiments with equivalent changes, still within the spirit covered by the specification and the drawings, shall be within the protection scope 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 connected to the coolant circuit through the coolant pipeline, and the heat exchange device being connected to the refrigerant main circuit through 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 connected to the cooling liquid circuit through the cooling liquid flow channel, and the liquid cooling plate being connected to the refrigerant branch through the refrigerant flow channel; A battery pack, wherein the battery pack is bonded to the liquid cooling plate; Wherein, the liquid inlet of the refrigerant flow channel is also provided with a temperature control switch. When the temperature of the battery pack meets the first preset condition, the temperature control switch is in a closed state, and the liquid cooling plate cools the battery pack through the coolant. When the temperature of the battery pack meets the second preset condition, the temperature control switch is in an open 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 rotationally 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 comprises a first door plate and a second door plate connected to each other, wherein the first door plate has a through hole, and the first door plate is located on a side of the second door plate away from the refrigerant flow channel liquid inlet, and has a first angle with 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 the temperature of the battery pack meets a second preset condition, the shape memory alloy can shrink and drive the first door panel to move along a first direction to open the liquid inlet of the refrigerant flow channel; When the temperature of the battery pack meets a first preset condition, the shape memory alloy can be restored to an initial state and drive the first door panel to move in a second direction to close the liquid inlet of the refrigerant flow channel; The first direction is opposite to the second direction.

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, 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 comprises a drain valve, which is mounted on the bottom wall of the groove; 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; 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 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 a 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 result 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 along the length direction and / or width direction of the liquid cooling plate, the cooling liquid flow channels and the refrigerant flow channels are alternately arranged and spaced apart; Wherein, the liquid inlet of the coolant flow channel is arranged adjacent to the liquid outlet of the refrigerant flow channel, and the liquid outlet of the coolant 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 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.

11. A method for controlling liquid inlet and outlet of an energy storage system, wherein the energy storage system comprises a liquid cooling plate, a battery pack, a valve and a liquid drain valve, wherein the liquid cooling plate comprises a cooling liquid flow channel and a refrigerant flow channel, wherein: The liquid inlet and outlet 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 the first temperature and the second temperature satisfy T1-T2<2°C, or the second temperature satisfies T2<25°C, the valve is controlled to rotate along the second direction y, and the drain valve is controlled to open to discharge the refrigerant in the refrigerant flow channel; When the first temperature and the second temperature satisfy T1-T2≥2°C, or the second temperature satisfies T2≥25°C, the valve is controlled to rotate along the first direction x, and the drain valve is controlled to close to prevent the refrigerant in the refrigerant flow channel from being discharged.

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