Liquid-cooled energy storage apparatus

Abstract

A liquid-cooled energy storage apparatus. The liquid-cooled energy storage apparatus comprises a box body, a plurality of battery packs, and a cluster-level liquid supply pipe extending in the height direction of the box body, the plurality of battery packs being located in the box body and being stacked in the height direction of the box body. The cluster-level liquid supply pipe is provided with a plurality of liquid supply branch pipes arranged at intervals in the height direction. Any one of the liquid supply branch pipes is used to place the cluster-level liquid supply pipe in communication with a liquid inlet of a liquid cooling plate of one battery pack among the plurality of battery packs. In the height direction, the position at which the liquid inlet of the liquid cooling plate is located is higher than the position at which a junction between the liquid supply branch pipe and the cluster-level liquid supply pipe is located. In the solution, due to the fact that the position at which the liquid inlet of the liquid cooling plate is located is higher in the height direction than the position at which the junction between the liquid supply branch pipe and the cluster-level liquid supply pipe is located, when cooling liquid in the liquid-cooled energy storage apparatus is replaced, the cooling liquid of the liquid cooling plate in the battery pack can be discharged from the liquid inlet of the liquid cooling plate into the cluster-level liquid supply pipe by using the gravity of the cooling liquid, so that the cooling liquid of the liquid cooling plate in the battery pack can be fully discharged and the liquid exchange ratio of the liquid-cooled energy storage apparatus is improved.

Description

Liquid-cooled energy storage device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on December 22, 2023, with application number 202323542482.7 and invention name “Liquid-Cooled Energy Storage Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of liquid-cooled firefighting technology, and in particular to a liquid-cooled energy storage device. Background Art

[0003] In the energy storage device, the battery packs in the battery cluster are connected to the liquid supply pipe and the liquid return pipe. The coolant circulates in the liquid supply pipe, the battery pack and the liquid return pipe. When the coolant flows into the battery pack, it can absorb and take away the heat of the battery pack in the energy storage device.

[0004] If the coolant stays in the battery pack for a long time, the pH value of the coolant will decrease, which can easily corrode the battery pack. The coolant needs to be replaced regularly.

[0005] In the current structure of energy storage devices, when the coolant in the battery pack is replaced, the original coolant in the battery pack is easily retained in the liquid cooling, reducing the rate of coolant replacement of the energy storage device and having a negative impact on the liquid cooling effect of the energy storage device.

[0006] Summary of the Invention

[0007] The technical problem to be solved by the present application is to provide a liquid-cooled energy storage device that can improve the coolant replacement ratio.

[0008] In a first aspect, the present application provides a liquid-cooled energy storage device comprising a liquid-cooled energy storage device housing, multiple battery packs, and a cluster-level liquid supply pipeline extending along the height direction of the housing, wherein the multiple battery packs are located within the housing and stacked along the height direction of the housing; the cluster-level liquid supply pipeline is provided with multiple liquid supply branches spaced apart in the height direction, each liquid supply branch being used to connect the cluster-level liquid supply pipeline to the liquid inlet of a liquid cooling plate of one of the multiple battery packs; and the liquid inlet of the liquid cooling plate is located at a higher position in the height direction than the connection between the liquid supply branch and the cluster-level liquid supply pipeline. In this solution, since the liquid inlet of the liquid cooling plate is located at a higher position in the height direction than the connection between the liquid supply branch and the cluster-level liquid supply pipeline, when the coolant of the liquid-cooled energy storage device is replaced, the coolant of the liquid cooling plate in the battery pack can be discharged from the liquid cooling plate's liquid inlet into the cluster-level liquid supply pipeline by its own gravity, which is beneficial for draining the coolant of the liquid cooling plate in the battery pack and improving the liquid replacement ratio of the liquid-cooled energy storage device.

[0009] In combination with the first aspect, in a possible implementation, the liquid-cooled energy storage device further includes a main-level liquid supply pipeline located below the cluster-level liquid supply pipeline, and the main-level liquid supply pipeline is connected to the cluster-level liquid supply pipeline. The coolant of the liquid-cooled energy storage device flows through the main-level liquid supply pipeline and the cluster-level liquid supply pipeline, and enters the liquid cooling plate of the battery pack to cool the battery pack. The main-level liquid supply pipeline is located below the cluster-level liquid supply pipeline, and the coolant supplies coolant to multiple battery packs from bottom to top. When the coolant of the liquid-cooled energy storage device is replaced, the coolant of multiple battery packs can use their own gravity to flow back to the main-level liquid supply pipeline from top to bottom, which is beneficial to drain the coolant of the liquid cooling plate in the battery pack and improve the liquid replacement ratio of the liquid-cooled energy storage device.

[0010] In conjunction with the first aspect, in one possible implementation, the primary liquid supply pipe extends along the length of the housing, is tilted relative to the horizontal plane, and is provided with a drain valve at the lower end of the primary liquid supply pipe, and the cluster-level liquid supply pipe is connected to the area between the two ends of the primary liquid supply pipe. When the liquid-cooled energy storage device replaces the coolant, the drain valve is opened. Since the primary liquid supply pipe is located below the multiple battery packs, the coolant in the cluster-level liquid supply pipe and the battery packs flows into the primary liquid supply pipe. Since the drain valve is located at the lower end of the primary liquid supply pipe, the coolant in the primary liquid supply pipe flows toward the location of the drain valve. This facilitates the clean drainage of the coolant in the primary liquid supply pipe and improves the liquid replacement ratio of the liquid-cooled energy storage device.

[0011] In combination with the first aspect, in one possible implementation, the main-stage liquid supply pipeline has a slope of 0.3%-1%, which can be beneficial for the liquid-cooled energy storage device to effectively discharge the coolant without occupying a large space of the liquid-cooled energy storage device due to the excessive slope of the main-stage liquid supply pipeline. If the downward slope of the main-stage liquid supply pipeline is low (less than 0.3%), the coolant cannot effectively utilize its own gravity to flow to the location of the drain valve. If the downward slope of the main-stage liquid supply pipeline is high (greater than 1%), the main-stage liquid supply pipeline will occupy a larger height space of the box, which will have a negative impact on the energy density of the liquid-cooled energy storage device.

[0012] In conjunction with the first aspect, in one possible implementation, the liquid-cooled energy storage device further includes a cluster-level liquid return pipe extending along the height of the housing. The cluster-level liquid return pipe is provided with multiple liquid return branches spaced apart in the height direction, each of which is configured to connect the cluster-level liquid return pipe to the liquid return port of a liquid cooling plate of one of the multiple battery packs. The height of the connection between the liquid return branches and the cluster-level liquid return pipe is located higher than the liquid inlet of the liquid cooling plate. When the coolant circulates in the liquid-cooled energy storage device, if the coolant contains a large amount of gas, the cooling effect of the coolant on the battery pack will be reduced. In this embodiment, due to the light nature of gas, the gas mixed with the coolant will flow upward after entering the battery pack. The height of the connection between the liquid return branches and the cluster-level liquid return pipe is located higher than the liquid inlet of the liquid cooling plate, which facilitates the discharge of gas from the liquid cooling plate in the battery pack and improves the cooling effect of the coolant on the battery pack.

[0013] In conjunction with the first aspect, in one possible implementation, the liquid-cooled energy storage device further includes a main-stage liquid return pipe disposed below the cluster-stage liquid return pipe, the main-stage liquid return pipe being in communication with the cluster-stage liquid return pipe. Since the main-stage liquid return pipe is disposed below the cluster-stage liquid return pipe, when the liquid-cooled energy storage device replaces the coolant, the coolant from the liquid-cooling plates in the multiple battery packs can flow through the liquid return branch pipe, the cluster-stage liquid return pipe, and the main-stage liquid return pipe. During the process of the coolant from the liquid-cooling plates in the battery pack flowing through the liquid return branch pipe, the cluster-stage liquid return pipe, and the main-stage liquid return pipe, the coolant flows generally from top to bottom. In this way, the coolant can utilize its own gravity to flow from the liquid-cooling plates in the battery pack to the main-stage liquid return pipe, which is beneficial for draining the coolant from the liquid-cooling plates in the battery pack cleanly and improving the liquid replacement ratio of the liquid-cooled energy storage device.

[0014] In conjunction with the first aspect, in one possible implementation, the primary return liquid pipe extends along the length of the housing, is tilted relative to the horizontal plane, and is provided with a drain valve at the lower end of the primary return liquid pipe. The cluster return liquid pipe is connected to the area between the two ends of the primary return liquid pipe. When the liquid-cooled energy storage device replaces the coolant, the drain valve is opened. Since the primary return liquid pipe is located below the multiple battery packs, the coolant in the cluster return liquid pipe and the battery packs flows into the primary return liquid pipe. Since the drain valve is located at the lower end of the primary return liquid pipe, the coolant in the primary return liquid pipe flows toward the location of the drain valve. This facilitates the clean discharge of the coolant in the primary return liquid pipe and improves the liquid replacement ratio of the liquid-cooled energy storage device.

[0015] In combination with the first aspect, in one possible implementation, the main-stage liquid return pipe has a slope of 0.3%-1%, which can be beneficial for the liquid-cooled energy storage device to effectively discharge the coolant, and does not occupy a large space of the liquid-cooled energy storage device due to the excessive slope of the main-stage liquid return pipe. If the downward slope of the main-stage liquid return pipe is low (less than 0.3%), the coolant cannot effectively utilize its own gravity to flow to the location of the drain valve. If the downward slope of the main-stage liquid return pipe is high (greater than 1%), the main-stage liquid return pipe will occupy a larger height space of the box, which will have a negative impact on the energy density of the liquid-cooled energy storage device.

[0016] In conjunction with the first aspect, in one possible implementation, the cluster-level liquid supply pipeline is provided with a control valve for regulating the flow of coolant; the liquid-cooled energy storage device is further provided with a sensor for collecting the temperature or water leakage of the battery pack, and the control valve is used to control the flow of coolant flowing through the cluster-level liquid supply pipeline according to the temperature or water leakage of the battery pack. The control valve can intelligently control the total flow of coolant flowing through multiple battery packs according to the temperature or water leakage of each battery pack. For example, if the temperature of the battery pack is too high, the flow of the cluster-level liquid supply pipeline can be increased through the control valve to increase the cooling force of the coolant cooling the battery pack to reduce the temperature of the battery pack. If the liquid cooling plate of the battery pack leaks coolant, the control valve can be automatically closed to stop supplying coolant to the battery pack, thereby avoiding continuous leakage of the battery pack and safety hazards (such as battery pack short circuit).

[0017] In conjunction with the first aspect, in one possible implementation, the cluster-level liquid return pipe is provided with a control valve for regulating the flow of coolant; the liquid-cooled energy storage device is further provided with a sensor for collecting the temperature or water leakage of the battery pack, and the control valve is used to control the flow of coolant flowing through the cluster-level liquid return pipe according to the temperature or water leakage of the battery pack. The control valve can intelligently control the total flow of coolant flowing through multiple battery packs based on the temperature or water leakage of each battery pack. For example, if the temperature of the battery pack is too high, the flow of the cluster-level liquid return pipe can be increased through the control valve to increase the cooling force of the coolant cooling the battery pack and reduce the temperature of the battery pack. If the liquid cooling plate of the battery pack leaks coolant, the control valve can be automatically closed to stop supplying coolant to the battery pack, thereby avoiding continuous leakage of the battery pack and safety hazards (such as battery pack short circuit).

[0018] In the second aspect, the present application provides a liquid-cooled energy storage device, which includes a box body, multiple battery packs, a cluster-level liquid supply pipe and a cluster-level liquid return pipe. Multiple battery packs are located in the box body and stacked along the height direction of the box body. The cluster-level liquid supply pipe extends along the height direction of the box body, and the cluster-level liquid supply pipe is provided with multiple liquid supply branches at intervals in the height direction. Any liquid supply branch is used to connect the cluster-level liquid supply pipe with the liquid inlet of the liquid cooling plate of one of the multiple battery packs; the cluster-level liquid return pipe extends along the height direction of the box body, and the cluster-level liquid return pipe is provided with multiple liquid return branches at intervals in the height direction. Any liquid return branch is used to connect the cluster-level liquid return pipe with the liquid return port of the liquid cooling plate of one of the multiple battery packs; in the height direction, the position of the connection between the return branch and the cluster-level liquid return pipe is higher than the position of the liquid inlet of the liquid cooling plate. When the coolant circulates in the liquid-cooled energy storage device, if the coolant contains a large amount of gas, the cooling effect of the coolant cooling the battery pack will be reduced. In this solution, since the gas is relatively light in texture, the gas mixed with the coolant will flow upward after entering the battery pack. In the height direction, the connection point between the return liquid branch pipe and the cluster-level return liquid pipe is located higher than the liquid inlet of the liquid cooling plate, which is conducive to discharging the gas in the liquid cooling plate in the battery pack and improving the cooling effect of the coolant cooling the battery pack.

[0019] In conjunction with the second aspect, in one possible implementation, the connection point between the liquid return branch pipe and the cluster-level liquid return pipe is located at a height higher than the liquid return port of the liquid cooling plate. After the coolant-mixed gas enters the battery pack, it flows upward. The connection point between the liquid return branch pipe and the cluster-level liquid return pipe is located at a height higher than the liquid return port of the liquid cooling plate. This also facilitates the discharge of gas from the liquid cooling plate in the battery pack, thereby improving the cooling effect of the coolant on the battery pack.

[0020] In conjunction with the second aspect, in one possible implementation, an exhaust valve is provided on the cluster-level liquid return pipe, and in the height direction, the exhaust valve is positioned higher than the location where any of the liquid return branches connect to the cluster-level liquid return pipe. When the coolant circulates in the liquid-cooled energy storage device, the gas mixed in the coolant will flow upward. In the height direction, the location where the liquid return branch connects to the cluster-level liquid return pipe is higher than the location of the liquid inlet of the liquid cooling plate. Gas mixed with the coolant in the battery pack is more likely to converge into the cluster-level liquid return pipe. In the height direction, the exhaust valve is provided on the cluster-level liquid return pipe at a location higher than the location where any of the liquid return branches connect to the cluster-level liquid return pipe, which is beneficial for discharging the gas collected in the cluster-level liquid return pipe and improving the liquid cooling effect of the liquid-cooled energy storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background technology, the drawings required for use in the embodiments of the present application or the background technology will be described below.

[0022] FIG1 is a schematic structural diagram of an energy storage device provided by the present application;

[0023] FIG2 is a front view of an energy storage device provided by the present application;

[0024] FIG3 is a schematic structural diagram of the energy storage device provided by the present application, omitting the box and part of the battery;

[0025] FIG4 is a front view of the battery pack provided in this application;

[0026] FIG5 is a cross-sectional view of the battery pack provided in this application;

[0027] FIG6 is a schematic structural diagram of the energy storage device provided by the present application omitting the battery cluster and liquid cooling pipeline;

[0028] FIG7 is a schematic structural diagram of the energy storage device provided by the present application omitting the battery cluster and the liquid cooling unit;

[0029] FIG8 is a schematic structural diagram of the liquid cooling unit provided in this application.

[0030] Description of reference numerals:

[0031] 1000, liquid-cooled energy storage device; 100, liquid cooling unit; 110, switching valve; 120, compressor; 130, condenser; 140, evaporator; 200, liquid cooling pipeline; 200a, drain valve; 200b, plug; 200c, control valve; 210, main-stage liquid supply pipeline; 220, cluster-level liquid supply pipeline; 230, main-stage liquid return pipeline; 240, cluster-level liquid return pipeline; 241, exhaust valve; 250, liquid supply branch pipe; 260, liquid return branch pipe; 300, battery cluster; 310, battery pack; 311, battery cell; 312, liquid cooling plate; 312a, liquid inlet; 312b, liquid return port; 313, shell; 400, box. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of this application clearer, this application will be further described in detail below with reference to the accompanying drawings.

[0033] Liquid-cooled energy storage devices play an important role in the process of renewable energy power generation (such as wind power generation, photovoltaic power generation, etc.). Liquid-cooled energy storage devices can stabilize the power generation system, provide energy backup, and improve power quality through the storage and release of energy, and have good application prospects. The liquid-cooled energy storage device may include a battery cluster and a power conversion unit. The battery cluster is used to store and release energy. The power conversion unit is used to convert the energy provided by the energy storage unit and provide it to the load. The power conversion unit can also convert energy from the power grid or other power generation elements and provide it to the battery cluster. Here, the battery cluster can include various types of energy storage elements, such as lithium-ion batteries, lead-acid batteries (or lead-acid batteries), and other energy storage batteries (referred to as battery clusters in this application), as well as supercapacitors (also known as electrochemical capacitors), etc. This application does not specifically limit the specific type of battery cluster. The power conversion unit may include a power storage converter (Power Control System, PCS) or a DC converter, etc. When the power conversion unit is an energy storage converter, the power conversion unit can realize AC and DC conversion during the charging or discharging process of the battery cluster. When storing and releasing electricity, the battery pack in a liquid-cooled energy storage device tends to generate heat. Coolant can be used to cool the battery pack in a liquid-cooled energy storage device, reducing the negative impact of this heat on the battery pack itself.

[0034] At present, liquid-cooled energy storage devices are cooled by circulating coolant. If the coolant remains in the battery pack of the battery cluster for a long time, the pH value of the coolant will decrease, which will easily corrode the battery pack. The coolant needs to be replaced regularly, and the coolant replacement ratio affects the cooling effect of the subsequent new coolant on the battery pack in the liquid-cooled energy storage device. On the other hand, if the liquid-cooled energy storage device retains a lot of old coolant, the pH value of the mixed coolant of new and old is still relatively low, and the coolant is highly acidic, which will still corrode the battery pack.

[0035] In view of this, the present application provides a liquid-cooled energy storage device that can improve the coolant replacement ratio. For ease of understanding, the length direction of the box is defined as the X-axis direction, the depth direction of the box is defined as the Y-axis direction, and the height direction of the box is defined as the Z-axis direction.

[0036] Referring to Figure 1 , a liquid-cooled energy storage device 1000 includes a housing 400, a liquid cooling unit 100, liquid cooling piping 200, and a battery cluster 300. Each battery cluster 300 is housed within the housing 400 and comprises multiple battery packs 310 (battery PACKs) arranged along the height (Z-axis) of the housing 400. Multiple battery packs 310 are connected in series or in parallel.

[0037] The liquid cooling pipe 200 is housed within the housing 400. The liquid cooling pipe 200 is used to connect the liquid cooling unit 100 and the individual battery packs 310 in the battery cluster 300. The liquid cooling pipe 200 is used to circulate coolant. Specifically, the coolant flows out of the liquid cooling unit 100, enters the liquid cooling pipe 200, and then enters the individual battery packs 310 in the battery cluster 300 from the liquid cooling pipe 200. The coolant entering the individual battery packs 310 in the battery cluster 300 absorbs heat from the individual battery packs 310 and is discharged to the liquid cooling pipe 200. The absorbed coolant then enters the liquid cooling unit 100 from the liquid cooling unit 100. The coolant is then cooled by the liquid cooling unit 100 and discharged to the liquid cooling pipe 200, repeating the cycle. Specifically, referring to FIG2 , the liquid cooling circuit 200 includes a main-level liquid supply pipeline 210, a cluster-level liquid supply pipeline 220, a main-level liquid return pipeline 230, and a cluster-level liquid return pipeline 240. The main-level liquid return pipeline 230 and the main-level liquid supply pipeline 210 are arranged below the battery cluster 300. The main-level liquid supply pipeline 210 is connected to the liquid cooling unit 100, and the cluster-level liquid supply pipeline 220 is connected to the main-level liquid supply pipeline 210. The cluster-level liquid supply pipeline 220 is connected to each battery pack 310 through multiple liquid supply branches 250. The coolant flows through the liquid cooling unit 100, the main liquid supply pipe 210, the cluster liquid supply pipe 220, the liquid supply branch pipe 250, and each battery pack 310 of the battery cluster 300 in sequence. Each battery pack 310 in the battery cluster 300 absorbs heat, and then flows through the return liquid branch pipe 260, the cluster liquid return pipe 240, and the main liquid return pipe 230, and returns to the liquid cooling unit 100. The liquid cooling unit 100 cools the coolant flowing into the main liquid return pipe 230, and then discharges it to the main liquid supply pipe 210, and the cycle continues.

[0038] The liquid-cooled energy storage device 1000 circulates coolant to absorb heat from the liquid-cooling plate 312 of the battery pack 310 in the battery cluster 300. As the coolant circulates in the liquid-cooled energy storage device 1000, the pH value of the coolant decreases. The liquid-cooling plate 312 of the battery pack 310 is generally made of metal. Coolant with a decreased pH value will corrode the liquid-cooling plate 312, easily causing coolant leakage from the liquid-cooling plate 312 in the battery cluster 300. Regularly replacing the coolant in the liquid-cooled energy storage device 1000 can improve the situation where the coolant corrodes the liquid-cooling plate 312 due to a decrease in pH value. The coolant replacement cycle for the liquid-cooled energy storage device 1000 is 3 years, 4 years, 5 years, 6 years, 7 years, etc. This application does not specifically limit the coolant replacement cycle for the liquid-cooled energy storage device 1000. During the process of replacing the coolant in the liquid-cooled energy storage device 1000 , if too much coolant remains in the battery packs 310 in the battery cluster 300 (the liquid replacement ratio of the liquid-cooled energy storage device 1000 is low), the coolant remaining in the battery packs 310 will still corrode the liquid cooling plate 312 of the battery packs 310 .

[0039] In the present application, please refer to Figures 3 and 4. The battery cluster 300 corresponds to a cluster-level liquid supply pipe 220, wherein the cluster-level liquid supply pipe 220 extends along the height direction of the box (Z-axis direction), and the cluster-level liquid supply pipe 220 is provided with a plurality of liquid supply branches 250 at intervals in the height direction. Any liquid supply branch 250 is used to connect the cluster-level liquid supply pipe 220 with the liquid inlet 312a of the liquid cooling plate 312 of a battery pack 310 among the multiple battery packs 310. Since the liquid inlet 312a of the liquid cooling plate 312 is located higher than the connection between the liquid supply branch pipe 250 and the cluster-level liquid supply pipe 220 in the height direction, when the coolant of the liquid-cooled energy storage device 1000 is replaced, the coolant of the liquid cooling plate 312 in the battery pack 310 can be discharged from the liquid inlet 312a of the liquid cooling plate 312 into the cluster-level liquid supply pipe 220 by its own gravity, which is beneficial to draining the coolant of the liquid cooling plate 312 in the battery pack 310 and improving the liquid replacement ratio of the liquid-cooled energy storage device 1000.

[0040] The cluster-level liquid supply pipe 220 is connected to the main-level liquid supply pipe 210. The main-level liquid supply pipe 210 extends along the length direction (X-axis direction) of the box 400. The main-level liquid supply pipe 210 is arranged below the cluster-level liquid supply pipe 220. Specifically, one end of the main-level liquid supply pipe 210 is connected to the liquid cooling unit 100, and the other end is provided with a drain valve 200a. The cluster-level liquid supply pipe 220 is connected to the area between the two ends of the main-level liquid supply pipe 210. The coolant of the liquid-cooled energy storage device 1000 flows through the main-level liquid supply pipe 210 and the cluster-level liquid supply pipe 220, and enters the liquid cooling plate 312 of the battery pack 310 to cool the battery pack 310. The main-level liquid supply pipe 210 is located below the cluster-level liquid supply pipe 220, and the coolant supplies coolant to multiple battery packs from bottom to top. When replacing the coolant in the liquid-cooled energy storage device 1000, the coolant in the multiple battery packs 310 can use its own gravity to flow back from top to bottom into the main liquid supply pipe 210, which is beneficial to draining the coolant in the liquid cooling plate 312 in the battery pack 310 and improving the liquid replacement ratio of the liquid-cooled energy storage device 1000.

[0041] The primary liquid supply pipe 210 is tilted relative to the horizontal plane and is provided with a drain valve 200a at the lower end of the main liquid supply pipe 210 along the length (X-axis) of the housing 400. When the liquid-cooled energy storage device 1000 is replacing the coolant, the drain valve 200a is opened. Because the primary liquid supply pipe 210 is positioned below the multiple battery packs 310, coolant in the cluster-level liquid supply pipes 220 and battery packs 310 flows toward the primary liquid supply pipe 210. Furthermore, because the drain valve 200a is located at the lower end of the primary liquid supply pipe 210, coolant in the primary liquid supply pipe 210 flows toward the drain valve 200a. This facilitates the clean draining of the coolant from the primary liquid supply pipe 210 and improves the liquid replacement ratio of the liquid-cooled energy storage device 1000.

[0042] The primary liquid return pipe 230 extends along the length of the housing (the X-axis). One end of the primary liquid return pipe 230 is connected to the liquid cooling unit 100, and a drain valve 200a is provided at the other end of the primary liquid return pipe 230. The primary liquid return pipe 230 is tilted relative to the horizontal plane, with the drain valve 200a located at the lower end of the primary liquid return pipe 230 along the length of the housing 400 (the X-axis). The cluster liquid return pipe 240 is connected to the area between the two ends of the primary liquid return pipe 230.

[0043] The cluster-level liquid return pipe 240 extends along the height (Z-axis) of the housing 400, with each cluster-level liquid return pipe 240 corresponding to a battery cluster 300. Multiple liquid return branches 260 are spaced apart along the height of the cluster-level liquid return pipe 240. Each liquid return branch 260 connects the cluster-level liquid return pipe 240 to the liquid return port 312b of the liquid cooling plate 312 of a battery pack 310 in a battery cluster 300.

[0044] The main-stage liquid return pipe 230 is located below the cluster-stage liquid return pipe 240. When the coolant of the liquid-cooled energy storage device 1000 is replaced, the coolant of the liquid-cooling plates 312 in the multiple battery packs 310 can flow through the liquid return branch pipe 260, the cluster-stage liquid return pipe 240 and the main-stage liquid return pipe 230. During the process of the coolant of the liquid-cooling plates 312 in the battery pack 310 flowing through the liquid return branch pipe 260, the cluster-stage liquid return pipe 240 and the main-stage liquid return pipe 230, the coolant flows roughly from top to bottom. In this way, the coolant can use its own gravity to flow from the liquid-cooling plates 312 of the battery pack 310 to the main-stage liquid return pipe 230, which is beneficial to draining the coolant of the liquid-cooling plates in the battery pack and improving the liquid replacement ratio of the liquid-cooled energy storage device.

[0045] Since the cluster-level liquid return pipe 240 is connected to the area between the two ends of the main-level liquid return pipe 230, and the drain valve 200a is provided at the lower end of the main-level liquid return pipe 230, it can be obtained that the position of the main-level liquid return pipe 230 where the drain valve 200a is located is lower than the position where the cluster-level liquid return pipe 240 is connected to the main-level liquid return pipe 230. In this way, the coolant in the cluster-level liquid return pipe 240 can be easily discharged into the main-level liquid return pipe 230, and then discharged from the main-level liquid return pipe 230 through the drain valve 200a to the outside of the main-level liquid return pipe. This is conducive to discharging the coolant in the cluster-level liquid return pipe 240 and the main-level liquid return pipe 230 to the outside of the main-level liquid return pipe through the drain valve 200a. Specifically, the primary liquid return pipe 230 has a slope of 0.3%-1%, which facilitates the effective discharge of coolant from the liquid-cooled energy storage device 1000 without occupying a large amount of space within the liquid-cooled energy storage device 1000 due to an excessively steep slope. If the primary liquid return pipe 230 has a low downward slope (less than 0.3%), the coolant cannot effectively flow to the location of the drain valve 200a by gravity. If the primary liquid return pipe 230 has a high downward slope (greater than 1%), the primary liquid return pipe 230 will occupy a large amount of height space within the housing 400, negatively impacting the energy density of the liquid-cooled energy storage device 1000.

[0046] In the embodiment of the present application, the height connection point of the liquid return branch 260 and the cluster-level liquid return pipe 240 is higher than the position of the liquid return branch 260 and the liquid return port 312b of the liquid cooling plate 312 in the battery pack. When the coolant circulates in the liquid-cooled energy storage device 1000, if the coolant contains a large amount of gas, the cooling effect of the coolant cooling the battery pack 310 will be reduced. In this embodiment, due to the light nature of the gas, the gas mixed with the coolant will flow upward after entering the battery pack 310. The height connection point of the liquid return branch 260 and the cluster-level liquid return pipe 240 is higher than the position of the liquid inlet 312a of the liquid cooling plate 312, which facilitates the discharge of gas from the liquid cooling plate 312 in the battery pack 310 and improves the cooling effect of the coolant cooling the battery pack 310.

[0047] In some embodiments, the connection between the liquid return branch pipe 260 and the cluster-level liquid return pipe 240 is located at a higher elevation than the connection between the liquid return branch pipe 260 and the liquid return port 312b of the liquid cooling plate 312 in the battery pack 310. After the coolant-mixed gas enters the battery pack 310, it flows upward. The connection between the liquid return branch pipe 260 and the cluster-level liquid return pipe 240 is located at a higher elevation than the liquid return port 312b of the liquid cooling plate 312, which facilitates the discharge of gas from the liquid cooling plate 312 in the battery pack 310 and improves the cooling effect of the coolant on the battery pack 310.

[0048] The liquid inlet 312a and the liquid return port 312b of the liquid cooling plate 312 are both connected to the flow channel of the liquid cooling plate 312. For the same battery pack 310, the position of the liquid inlet 312a can be higher than the position of the liquid return port 312b, or the position of the liquid inlet 312a can be lower than the position of the liquid return port 312b, or the position height of the liquid inlet 312a can be consistent with the position height of the liquid return port 312b.

[0049] The cluster-level liquid return pipe 240 is also provided with an exhaust valve 241. In terms of height, the exhaust valve 241 is positioned higher than the connection between any of the liquid return branches 260 and the cluster-level liquid return pipe 240. As the coolant circulates in the liquid-cooled energy storage device 1000, gas mixed with the coolant flows upward. In terms of height, the connection between the liquid return branch 260 and the cluster-level liquid return pipe 240 is positioned higher than the liquid inlet 312a of the liquid cooling plate 312. This makes it easier for gas mixed with the coolant in the battery pack 310 to converge into the cluster-level liquid return pipe 240. The exhaust valve 241 is positioned higher in terms of height than the connection between any of the liquid return branches 260 and the cluster-level liquid return pipe 240, facilitating the discharge of gas collected in the cluster-level liquid return pipe 240 and improving the cooling effect of the liquid-cooled energy storage device 1000. Specifically, the exhaust valve 241 may be disposed at the top of the cluster-level liquid return pipe 240 .

[0050] Please refer to Figures 4 and 5. Each battery pack 310 can include a shell 313, battery cells 311 and a liquid cooling plate 312. The battery cells 311 and the liquid cooling plate 312 are housed in the shell 313. The battery cells 311 and the liquid cooling plate 312 are stacked in a vertical direction. The battery cells 311 are in contact with the liquid cooling plate 312 and are located above the liquid cooling plate 312. The liquid cooling plate 312 is in contact with the battery cells 311. The liquid cooling plate 312 has a liquid inlet and a liquid return port. The liquid inlet and the liquid return port are both located on the outer side of the shell. The battery pack and the liquid cooling pipeline are arranged along the depth direction of the box. The liquid inlet and the liquid return port are located on an outer side of the battery pack facing the liquid cooling pipeline. The liquid inlet 312a and the liquid return port are both connected to the flow channel of the liquid cooling plate 312. The liquid inlet 312a is connected to the liquid supply branch 250, and the liquid return port is connected to the liquid return branch. When the coolant cools the battery pack 310, the coolant flows from the liquid supply branch pipe 250 through the liquid inlet 312a, and then enters the flow channel of the liquid cooling plate 312 from the liquid inlet 312a. Since the liquid cooling plate 312 is in contact with the battery cell 311, the coolant entering the flow channel of the liquid cooling plate 312 can absorb the heat of the battery cell 311, thereby reducing the temperature of the battery pack 310. The coolant entering the liquid cooling plate in the battery pack from the liquid inlet flows in the flow channel of the liquid cooling plate and flows out from the return liquid port of the liquid cooling plate to the return liquid branch pipe. The coolant absorbs the heat of the battery cell in the process of flowing in the flow channel of the liquid cooling plate. It should be noted that the battery cell 311 is the main heat source of the battery pack 310. By absorbing the temperature of the battery cell 311 in the battery pack 310 by the coolant, the temperature of the battery pack 310 can be effectively reduced. The coolant can be water, which has a high specific heat capacity. In a cycle in which the coolant circulates to cool the battery packs 310 in the battery cluster 300 , using water as the coolant can absorb more heat from the battery packs 310 , thereby achieving a better cooling effect.

[0051] Please refer to Figures 6 and 7. The liquid cooling unit 100 is housed in the box body 400. The box body 400 can be divided into multiple areas, and the multiple areas are arranged in sequence along the width direction of the box body 400. One of the areas is used to accommodate the liquid cooling unit 100, and the remaining areas are used to accommodate the battery clusters 300. All areas for accommodating the battery clusters 300 are located on one side of the area for accommodating the liquid cooling unit 100 along the length direction (X-axis direction) of the box body 400. In order to facilitate the circulation of liquid supply to the battery packs 310 of each battery cluster 300, multiple cluster-level liquid supply pipes 220 are arranged at intervals along the width direction of the box body 400; cluster-level liquid return pipes 240 are arranged at intervals along the length direction (X-axis direction) of the box body 400. As will be appreciated, when the coolant is supplied to the battery packs 310 of the battery cluster 300, the coolant is supplied to the battery packs 310 of each battery cluster 300, approximately from left to right along the length of the housing (positive direction of the X-axis). The coolant in the battery packs 310 of each battery cluster 300 returns to the liquid cooling unit 100 approximately from right to left along the length of the housing 400 (negative direction of the X-axis). This results in fewer reversing nodes during the electrolyte circulation process. This reduces the number of reversing components required for the liquid cooling circuit 200, reduces the space occupied by the reversing components in the liquid-cooled energy storage device 1000, and improves the energy density of the liquid-cooled energy storage device 1000. Fewer reversing nodes during the electrolyte circulation process also reduces the flow resistance of the coolant during circulation, shortens the coolant circulation cycle, and improves the cooling efficiency of the battery packs 310 in the liquid-cooled battery cluster 300.

[0052] Specifically, there are multiple cluster-level liquid supply pipes 220, which are spaced apart along the width of the housing 400, and each of the multiple cluster-level liquid supply pipes 220 corresponds to the number of battery clusters 300. There are also multiple cluster-level liquid return pipes 240, which are spaced apart along the width of the housing 400, and each of the multiple cluster-level liquid return pipes 240 corresponds to the number of battery clusters 300. Each main-level liquid supply pipe 210 supplies coolant to multiple battery clusters 300 through multiple cluster-level liquid supply pipes 220, and the multiple battery clusters 300 return coolant to the cluster-level liquid return pipes 240 through the multiple cluster-level liquid return pipes 240. The multiple battery clusters 300 are arranged sequentially along the width of the housing 400, the multiple cluster-level liquid supply pipes 220 are spaced apart along the width of the housing 400, and the multiple cluster-level liquid return pipes 240 are spaced apart along the length (X-axis) of the housing 400. This makes the layout of the liquid cooling pipes 200 and battery clusters 300 of the liquid-cooled energy storage device 1000 more regular, which is conducive to improving the energy density of the liquid-cooled energy storage device 1000. The number of battery clusters 300 can be 1, 2, 3, 4, 5, 6, etc., and this application does not impose a specific limit on the number of battery clusters 300.

[0053] Referring to Figure 8 , in the embodiment provided herein, the liquid cooling unit 100 may include a compressor 120, a condenser 130, and an evaporator 140. The outlet of the compressor 120 is connected to the inlet of the condenser 130, which in turn is connected to the inlet of the evaporator 140. The outlet of the evaporator 140 is connected to the inlet of the compressor 120. The compressor 120 is capable of compressing a heat exchange medium and delivering the compressed heat exchange medium to the condenser 130. The condenser 130 condenses the heat exchange medium, liquefying it. The liquefied heat exchange medium then enters the evaporator 140, which evaporates the liquefied heat exchange medium, vaporizing it. The heat exchange medium vaporized by the evaporator 140 is then delivered to the compressor 120, and the cycle continues. The heat exchange medium may be Freon. In the liquid cooling unit 100, the evaporator 140 absorbs heat from the coolant entering the liquid cooling unit 100 as it evaporates the heat exchange medium, thereby reducing the coolant's temperature. It should be noted that the liquid cooling unit 100 is provided with an exhaust valve 241. During the process of coolant from the primary return line 230 being discharged into the liquid cooling unit 100, gas present in the coolant can be discharged outside the liquid cooling unit 100 through the exhaust valve 241. By removing gas from the coolant, the coolant's cooling effect on the battery cells 311 in the battery cluster 300 is improved.

[0054] In the embodiment provided in the present application, the liquid cooling unit 100 is provided with a switch valve 110, which can control the connection between the main-stage liquid supply pipe 210 and the liquid cooling unit 100, and the switch valve 110 can be a butterfly valve. When the switch valve 110 is open, the main-stage liquid supply pipe 210 is connected to the liquid cooling unit 100, and the main-stage liquid supply pipe 210 and the liquid cooling unit 100 can communicate with each other. When the switch valve 110 is closed, the main-stage liquid supply pipe 210 is not connected to the liquid cooling unit 100, and the coolant in the liquid cooling unit 100 cannot flow into the main-stage liquid supply pipe 210. The liquid cooling unit 100 is also provided with a switch valve 110, which can control the connection between the main-stage liquid return pipe 230 and the liquid cooling unit 100, and the switch valve 110 can be a butterfly valve. When the on-off valve 110 is open, the primary liquid return pipe 230 is connected to the liquid cooling unit 100, and the primary liquid return pipe 230 and the liquid cooling unit 100 can communicate with each other. When the on-off valve 110 is closed, the primary liquid return pipe 230 is disconnected from the liquid cooling unit 100, and the coolant in the primary liquid return pipe 230 cannot flow into the liquid cooling unit 100.

[0055] Primary liquid supply pipe 210 is provided with a plug 200b. Plug 200b is located at the port of primary liquid supply pipe 210 remote from the liquid cooling unit. Plug 200b is used to seal the port of primary liquid supply pipe 210 remote from the liquid cooling unit 100. Plug 200b blocks the port of primary liquid supply pipe 210 remote from the liquid cooling unit 100, preventing dust and impurities from entering primary liquid supply pipe 210. This reduces the likelihood of dust and impurities entering the coolant and affecting the coolant's ability to cool the battery cells 311 through the liquid cold plate 312.

[0056] The primary liquid return pipe 230 is provided with a plug 200b, which is used to seal the end of the primary liquid return pipe 230 away from the liquid cooling unit 100. The plug 200b is located at the end of the primary liquid return pipe 230 away from the liquid cooling unit 100. The plug prevents dust and impurities from entering the primary liquid return pipe 230, thereby reducing the probability of dust and impurities entering the coolant and affecting the coolant's ability to cool the battery cells 311 through the liquid cold plate 312.

[0057] In the embodiments provided herein, each of the multiple cluster-level liquid supply pipes 220 is provided with a control valve 200c, or each of the multiple cluster-level liquid return pipes 240 is provided with a control valve 200c. The control valve 200c is capable of regulating flow, and the control valve 200c may be an electrically operated regulating valve. When the flow of the control valve 200c is zero, the control valve 200c is closed. The control valve 200c controls the flow of the cluster-level liquid supply pipe 220 in which it is located, or the control valve 200c controls the flow of the cluster-level liquid return pipe 240 in which it is located. For example, when the temperature of a battery cluster 300 in the liquid-cooled energy storage device 1000 is high, the control valve 200c is used to increase the flow of coolant flowing through the cluster-level liquid supply pipe 220 or cluster-level liquid return pipe 240 corresponding to the battery cluster 300, thereby improving the cooling effect of the liquid cooling plate 312 in the battery cluster 300 and reducing the temperature of the battery cluster 300. If the temperature of a battery cluster 300 in the liquid-cooled energy storage device 1000 is low, the flow rate of coolant flowing through the corresponding cluster-level liquid supply pipe 220 or cluster-level liquid return pipe 240 of the battery cluster 300 can be reduced by controlling the valve 200c, or the control valve 200c can be closed to reduce the flow rate of coolant flowing through the corresponding cluster-level liquid supply pipe 220 or cluster-level liquid return pipe 240 of the battery cluster 300 to zero.

[0058] In the embodiment provided in the present application, the liquid-cooled energy storage device 1000 is further provided with sensors, and the number of sensors may be multiple, some of the sensors may be temperature sensors, and some of the sensors may be water immersion sensors. The temperature sensor can collect the temperature of the battery cluster 300, and the water immersion sensor can collect whether the battery cluster 300 is leaking. The water immersion sensor can be arranged on the main-level return liquid pipe or / and the main-level supply liquid pipe. The control valve 200c can control the flow rate of the coolant flowing through the cluster-level return liquid pipe 240 or the cluster-level supply liquid pipe 220 corresponding to the battery cluster 300 according to the temperature of the battery cluster 300 collected by the temperature sensor. The control valve 200c can control the flow rate of the coolant flowing through the cluster-level return liquid pipe 240 or the cluster-level supply liquid pipe 220 corresponding to the battery cluster 300 according to the water leakage of each battery cluster 300 collected by the water immersion sensor.

[0059] In some embodiments, the flow rate of coolant flowing through each control valve 200c can be remotely controlled via a terminal. For example, a temperature sensor collects the temperature of a battery cluster 300. The temperature sensor then transmits the collected temperature of the battery cluster 300 to the terminal. Based on the received temperature, the terminal sends a control instruction to the control valve 200c to control the opening of the control valve 200c, thereby controlling the flow rate of coolant flowing through the cluster-level liquid return pipe 240 or cluster-level liquid supply pipe 220 corresponding to the battery cluster 300. It should be noted that if the temperature of the battery cluster 300 exceeds a preset threshold, the terminal sends a control instruction to increase the opening of the control valve 200c, thereby increasing the flow rate in the cluster-level liquid supply pipe 220 or cluster-level liquid return pipe 240 corresponding to the battery cluster 300.

[0060] For example, a water sensor detects a battery cluster 300 leak. The sensor transmits the detected leak information to the terminal. Based on the leak information, the terminal sends a control instruction to control valve 200c to control the opening of control valve 200c, thereby controlling the flow of coolant flowing through the corresponding cluster-level liquid return pipe 240 or cluster-level liquid supply pipe 220. It should be noted that if a battery cluster 300 leaks, the terminal sends a control instruction to reduce the opening of control valve 200c or close it, thereby reducing the flow of coolant flowing through the corresponding cluster-level liquid return pipe 240 or cluster-level liquid supply pipe 220, or reducing the flow of coolant through the corresponding cluster-level liquid return pipe 240 or cluster-level liquid supply pipe 220 to zero. By ceasing the supply of coolant to the battery cluster 300, the terminal prevents continued leakage of the battery cluster 300, which could lead to safety hazards (such as a short circuit in the battery cluster 300).

[0061] In the embodiment provided herein, each battery cluster 300 is provided with a floor drain. If the liquid cooling plate 312 in a battery cluster 300 leaks coolant, the floor drain in the battery cluster 300 can drain the leaked coolant from the liquid cooling plate 312 out of the battery cluster 300. This reduces the risk of a short circuit in the battery cluster 300 caused by a leak in the liquid cooling plate 312.

[0062] The first, second, third, fourth and various numerical numbers involved in this document are only for the convenience of description and are not intended to limit the scope of this application.

[0063] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0064] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A liquid-cooled energy storage device, characterized in that: The energy storage device comprises: Box; A plurality of battery packs located in the box and stacked along the height direction of the box; A cluster-level liquid supply pipeline extends along the height direction of the box body, and the cluster-level liquid supply pipeline is provided with a plurality of liquid supply branches at intervals in the height direction, and any liquid supply branch is used to connect the cluster-level liquid supply pipeline with the liquid inlet of a liquid cooling plate of a battery pack among the plurality of battery packs; in the height direction, the position of the liquid inlet of the liquid cooling plate is higher than the position of the connection between the liquid supply branch and the cluster-level liquid supply pipeline.

2. The liquid-cooled energy storage device according to claim 1, characterized in that: The liquid-cooled energy storage device further includes a main-level liquid supply pipeline located below the cluster-level liquid supply pipeline, and the main-level liquid supply pipeline is in communication with the cluster-level liquid supply pipeline.

3. The liquid-cooled energy storage device according to claim 2, characterized in that: The main-stage liquid supply pipeline extends along the length direction of the box body, and is arranged to be inclined relative to the horizontal plane. A drain valve is provided at the lower end of the main-stage liquid supply pipeline in the length direction of the box body, and the cluster-stage liquid supply pipeline is connected to the area between the two ends of the main-stage liquid supply pipeline.

4. The liquid-cooled energy storage device according to claim 3, characterized in that: The main-stage liquid supply pipeline has an inclination gradient of 0.3%-1%.

5. The liquid-cooled energy storage device according to any one of claims 1 to 4, characterized in that: The liquid-cooled energy storage device also includes a cluster-level liquid return pipe, which extends along the height direction of the box body. The cluster-level liquid return pipe is provided with a plurality of liquid return branches at intervals in the height direction, and any liquid return branch is used to connect the cluster-level liquid return pipe with the liquid return port of a liquid cooling plate of a battery pack among the plurality of battery packs; in the height direction, the position of the connection between the liquid return branch and the cluster-level liquid return pipe is higher than the position of the liquid inlet of the liquid cooling plate.

6. The liquid-cooled energy storage device according to claim 5, characterized in that: The liquid-cooled energy storage device further includes a main-level liquid return pipe disposed below the cluster-level liquid return pipe, and the main-level liquid return pipe is in communication with the cluster-level liquid return pipe.

7. The liquid-cooled energy storage device according to claim 6, characterized in that: The main-stage liquid return pipe extends along the length direction of the box body, and the main-stage liquid return pipe is inclined relative to the horizontal plane. The main-stage liquid return pipe is provided with a drain valve at the lower end of the two ends in the length direction of the box body, and the cluster-stage liquid return pipe is connected to the area between the two ends of the main-stage liquid return pipe.

8. The liquid-cooled energy storage device according to claim 7, characterized in that: The slope of the primary liquid return pipeline is 0.3%-1%.

9. The liquid-cooled energy storage device according to claim 1, characterized in that: The cluster-level liquid supply pipeline is provided with a control valve for adjusting the flow rate of coolant; the liquid-cooled energy storage device is also provided with a sensor, which is used to collect the temperature or water leakage of the battery pack, and the control valve is used to control the flow rate of coolant flowing through the cluster-level liquid supply pipeline according to the temperature or water leakage of the battery pack.

10. The liquid-cooled energy storage device according to claim 5, characterized in that: The cluster-level liquid return pipe is provided with a control valve for adjusting the flow rate of the coolant; the liquid-cooled energy storage device is also provided with a sensor, the sensor is used to collect the temperature or water leakage of the battery pack, and the control valve is used to control the flow rate of the coolant flowing through the cluster-level liquid return pipe according to the temperature or water leakage of the battery pack.

11. A liquid-cooled energy storage device, characterized in that: include: Box; A plurality of battery packs located in the box and stacked along the height direction of the box; a cluster-level liquid supply pipeline extending in the height direction of the box body, wherein the cluster-level liquid supply pipeline is provided with a plurality of liquid supply branches at intervals in the height direction, and any liquid supply branch is used to connect the cluster-level liquid supply pipeline with a liquid inlet of a liquid cooling plate of one of the plurality of battery packs; A cluster-level liquid return pipe extending in the height direction of the box, wherein the cluster-level liquid return pipe is provided with a plurality of liquid return branches at intervals in the height direction, and any liquid return branch is used to connect the cluster-level liquid return pipe with the liquid return port of a liquid cooling plate of a battery pack among the plurality of battery packs; The position where the liquid return branch pipe is connected to the cluster-level liquid return pipe is higher than the position of the liquid inlet of the liquid cooling plate.

12. The liquid-cooled energy storage device according to claim 11, characterized in that: In the height direction, the position of the connection between the liquid return branch pipe and the cluster-level liquid return pipe is higher than the position of the liquid return port of the liquid cooling plate.

13. The liquid-cooled energy storage device according to claim 11 or 12, characterized in that: The cluster-level liquid return pipe is provided with an exhaust valve, and the position of the exhaust valve in the height direction is higher than the position where any of the liquid return branches is connected to the cluster-level liquid return pipe.

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