Submerged liquid-cooled energy storage system and its control method

Abstract

This invention relates to the field of thermal management technology for energy storage systems, and particularly to an immersion liquid-cooled energy storage system and its control method. The immersion liquid-cooled energy storage system includes a battery pack, a controller, and a liquid-cooling unit. The battery pack has an inner cavity, a first liquid inlet, and a second liquid inlet. The first liquid inlet is equipped with a first electric valve, and the second liquid inlet is equipped with a second electric valve. A liquid level sensor is installed inside the inner cavity. The liquid-cooling unit is connected to the first liquid inlet via a first pipe and to the second liquid inlet via a second pipe. The liquid level sensor, the first electric valve, the second electric valve, and the liquid-cooling unit are all electrically connected to the controller. The control method for this immersion liquid-cooled energy storage system is used to control the aforementioned immersion liquid-cooled energy storage system. This invention provides an immersion liquid-cooled energy storage system and its control method to alleviate the technical problems in the prior art where the reliance on manual observation to control the liquid level in the battery pack's injection and cooling cycle leads to low accuracy in liquid level control and the inability to monitor it in real time.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology for energy storage systems, and in particular to an immersion liquid-cooled energy storage system and its control method. Background Technology

[0002] Immersion liquid-cooled energy storage systems are thermal management systems that completely immerse energy storage batteries (usually lithium-ion batteries) in a specially designed insulating coolant. This technology achieves heat exchange through direct contact between the battery and the coolant, removing the heat generated during battery charging and discharging. This helps improve battery consistency, extend cycle life, and reduce system auxiliary energy consumption.

[0003] A typical submerged liquid-cooled energy storage system includes a battery pack and a liquid cooling unit. The batteries in the battery pack are directly immersed in coolant, and the battery pack is connected between the outlet and return inlet of the liquid cooling unit. The submerged liquid-cooled energy storage system includes a liquid injection mode and a cooling cycle mode. In the liquid injection mode, the liquid cooling unit injects coolant into the battery pack through the outlet until the coolant level reaches a preset height. Then, the system switches to the cooling cycle mode. At this time, the liquid cooling unit starts its circulation pump, and the coolant flows out from the outlet of the liquid cooling unit, typically spraying in from the top of the battery pack. After absorbing heat on the surface of the submerged batteries, it flows back from the bottom or side of the battery pack to the return inlet of the liquid cooling unit, where it is cooled again and circulated once more.

[0004] However, in the existing technology, in the liquid injection mode, the operator visually observes and controls the liquid injection height through the liquid level observation hole set on the battery pack. The manual control has low precision and cannot accurately control the liquid injection height. In the cooling cycle mode, the operator relies on regular manual inspections to monitor changes in the liquid level in the battery pack. When the liquid level in the battery pack is found to be too low, liquid is manually added; when the liquid level is too high, liquid is manually drained. If the inspection is not timely, the liquid level in the battery pack may be too low, leading to poor battery heat dissipation or even thermal runaway, or the liquid level in the battery pack may be too high, posing a risk of coolant overflow. Summary of the Invention

[0005] The purpose of this invention is to provide an immersion liquid-cooled energy storage system to at least alleviate the technical problems in the prior art that rely on manual observation to control the liquid level of the battery pack during liquid injection and cooling cycle, resulting in low accuracy of liquid injection height control and inability to monitor in real time.

[0006] The present invention also aims to provide a control method for an immersion liquid-cooled energy storage system, so as to further alleviate the technical problems in the prior art that rely on manual observation to control the liquid level of the battery pack injection and cooling cycle, resulting in low accuracy of liquid level control and inability to monitor in real time.

[0007] Based on the first objective mentioned above, the present invention provides an immersion liquid-cooled energy storage system, including a battery pack, a controller, and a liquid-cooled host; The battery pack is provided with an inner cavity and a first liquid port and a second liquid port that are both connected to the inner cavity. The first liquid port is provided with a first electric valve, the second liquid port is provided with a second electric valve, and a liquid level sensor for monitoring the liquid level height of the coolant is provided in the inner cavity. The liquid cooling unit has a switchable liquid injection mode and a cooling cycle mode, and the liquid cooling unit is connected to the first liquid port through a first pipe and to the second liquid port through a second pipe. The liquid level sensor, the first electric valve, the second electric valve, and the liquid cooling unit are all electrically connected to the controller; The controller is configured as follows: In the liquid injection mode, the liquid cooling host is controlled to input coolant into the inner cavity through the second pipeline and the second liquid port, and the liquid level height of the coolant in the inner cavity is monitored by the liquid level sensor, and the first electric valve and the second electric valve of the battery pack are opened and closed accordingly. In the refrigeration cycle mode, the liquid cooling host is controlled to input coolant into the inner cavity through the first pipe and the first liquid port, and the coolant in the inner cavity returns to the liquid cooling host through the second liquid port and the second pipe. The first electric valve and the second electric valve of the battery pack are opened and closed accordingly based on the liquid level height of the coolant in the inner cavity monitored by the liquid level sensor.

[0008] Furthermore, the liquid level sensor is used to detect the liquid level height of the coolant in the inner cavity at three signal levels: low, middle, and high. The low level is lower than the middle level, and the high level is higher than the middle level. The controller is configured as follows: In the liquid injection mode, both the first and second electric valves of the battery pack are opened, and the liquid cooling host is controlled to input coolant into the inner cavity through the second pipeline and the second liquid port; when the liquid level sensor detects that the coolant level in the inner cavity reaches the median height, the first and second electric valves of the battery pack are closed accordingly. In the refrigeration cycle mode, the first electric valve and the second electric valve of the battery pack are both opened, and the liquid cooling host is controlled to input coolant into the inner cavity through the first pipe and the first liquid port, and the coolant in the inner cavity returns to the liquid cooling host through the second liquid port and the second pipe. When the liquid level sensor detects that the coolant level in the inner cavity reaches the low level, the second electric valve is closed and the first electric valve remains open. When the liquid level sensor detects that the coolant level in the inner cavity rises to the middle level, the second electric valve is opened. When the liquid level sensor detects that the coolant level in the inner cavity reaches the high level, the first electric valve is closed and the second electric valve remains open. When the liquid level sensor detects that the coolant level in the inner cavity drops to the middle level, the first electric valve is opened.

[0009] Furthermore, the immersion liquid-cooled energy storage system includes multiple battery packs, each of which has a first liquid port connected to the first pipeline and a second liquid port connected to the second pipeline, thereby the multiple battery packs are connected in parallel to form a battery module; In the liquid injection mode, when the liquid level sensor in one or more of the battery packs detects that the coolant level in the inner cavity has reached the median height, the controller correspondingly closes the first electric valve and the second electric valve of the one or more battery packs and correspondingly reduces the flow rate of the liquid cooling host until the liquid level sensor in all the battery packs detects that the coolant level in the inner cavity has reached the median height, the controller controls the liquid cooling host to shut down. In the cooling cycle mode, when the liquid level sensor in one or more of the battery packs detects that the coolant level in the inner cavity reaches the low level, the controller correspondingly closes the second electric valve of the one or more battery packs and keeps the first electric valve of the one or more battery packs open; when the liquid level sensor in one or more of the battery packs detects that the coolant level in the inner cavity rises to the middle level, the controller correspondingly opens the second electric valve of the one or more battery packs. When the level sensor in one or more of the battery packs detects that the coolant level in the cavity has reached the high level, the controller closes the first electric valve of the battery pack while keeping the second electric valve of the battery pack open, and reduces the flow rate of the liquid cooling unit accordingly. When the level sensor in one or more of the battery packs detects that the coolant level in the cavity has dropped to the middle level, the controller opens the first electric valve of the battery pack and increases the flow rate of the liquid cooling unit accordingly.

[0010] Furthermore, the battery pack is provided with a pressure relief port communicating with the inner cavity, and a two-way ventilated pressure relief valve is provided at the pressure relief port.

[0011] Furthermore, the first liquid outlet is located at or near the top of the battery pack, and the second liquid outlet is located at or near the bottom of the battery pack.

[0012] By adopting the above technical solution, the immersion liquid-cooled energy storage system of the present invention has at least the following beneficial effects: It should be noted that the liquid cooling unit has a first host port and a second host port. For example, the first host port is connected to the first liquid port through a first pipe, and the second host port is connected to the second liquid port through a second pipe.

[0013] When liquid filling is required, the operator sends a liquid filling command to the controller, which then switches the liquid cooling unit to liquid filling mode. In liquid filling mode, the controller opens both the first and second electric valves of the battery pack and controls the second main unit port of the liquid cooling unit as the liquid outlet. At this time, the second main unit port inputs coolant into the inner cavity through the second pipeline and the second liquid outlet, causing the coolant level in the inner cavity of the battery pack to gradually rise. When the liquid level sensor detects that the coolant level in the inner cavity has reached the preset median height, the first and second electric valves of the battery pack are closed accordingly, so that the coolant level in the inner cavity is maintained at the preset median height.

[0014] After the liquid filling is complete, the system can switch to the cooling cycle mode for normal operation. In the cooling cycle mode, the controller opens both the first and second electric valves of the battery pack, and controls the first main unit port of the liquid cooling unit as the liquid outlet and the second main unit port as the liquid return port. At this time, the first main unit port inputs coolant into the inner cavity through the first pipeline and the first liquid outlet. After the coolant flows over the surface of the submerged battery and absorbs heat, it returns to the liquid cooling unit through the second liquid outlet and the second pipeline, and then through the second main unit port. During this process, the coolant level in the inner cavity of the battery pack is constantly changing. When the level sensor detects that the coolant level in the inner cavity is lower than the preset median height, the second electric valve is closed and the first electric valve remains open, so that the battery pack inner cavity continues to receive coolant without any more coolant flowing out. As a result, the coolant level in the battery pack inner cavity gradually rises. When the level sensor detects that the coolant level in the inner cavity has risen to the preset median height, the second electric valve is opened to continue cooling the battery in the battery pack.

[0015] When the level sensor detects that the coolant level in the inner cavity is higher than the preset median height, the first electric valve is closed and the second electric valve remains open, so that the coolant continues to flow out of the battery pack cavity and no longer flows in. As a result, the coolant level in the inner cavity of the battery pack gradually decreases. When the level sensor detects that the coolant level in the inner cavity has decreased to the preset median height, the first electric valve is opened to continue cooling the battery in the battery pack.

[0016] This design allows the immersion liquid-cooled energy storage system provided by this invention to monitor the liquid level in real time via a liquid level sensor. The controller automatically manages the two electric valves of the battery pack and the liquid cooling unit, achieving complete automation of the liquid injection and operation processes. The automated liquid injection process eliminates the need for manual observation of the liquid level observation hole or manual valve operation, significantly reducing the difficulty and risk of error associated with manual operation, while improving injection accuracy and efficiency. The automated operation process automatically replenishes liquid when it is too low and automatically drains liquid when it is too high, ensuring that the coolant level in each battery pack is always maintained within a safe range. This effectively reduces the risk of poor battery heat dissipation, temperature rise, or even thermal runaway due to low liquid levels, while also eliminating the safety hazard of coolant overflow due to excessively high liquid levels. Compared to existing technologies that rely on manual observation and inspection, this invention achieves real-time and precise control of the liquid level within the battery pack.

[0017] Based on the second objective mentioned above, the present invention provides a control method for an immersion liquid-cooled energy storage system, used to control the aforementioned immersion liquid-cooled energy storage system, the control method comprising: In liquid injection mode, the controller controls the liquid cooling host to input coolant into the inner cavity of the battery pack through the second pipeline and the second liquid port, and according to the liquid level height of the coolant in the inner cavity monitored by the liquid level sensor in the battery pack, the first electric valve and the second electric valve of the battery pack are opened and closed accordingly. In the cooling cycle mode, the controller controls the liquid cooling host to input coolant into the inner cavity of the battery pack through the first pipe and the first liquid port, and the coolant in the inner cavity returns to the liquid cooling host through the second liquid port and the second pipe. The controller also controls the opening and closing of the first electric valve and the second electric valve of the battery pack according to the liquid level height of the coolant in the inner cavity monitored by the liquid level sensor in the battery pack.

[0018] Furthermore, the liquid level sensor is used to detect the liquid level height of the coolant in the inner cavity at three signal levels: low, middle, and high. The low level is lower than the middle level, and the high level is higher than the middle level. In the liquid injection mode, the controller controls both the first and second electric valves of the battery pack to open, and controls the liquid cooling host to input coolant into the inner cavity through the second pipeline and the second liquid port; when the liquid level sensor detects that the coolant level in the inner cavity reaches the median height, the controller correspondingly closes the first and second electric valves of the battery pack. In the refrigeration cycle mode, the controller controls both the first and second electric valves of the battery pack to open, and controls the liquid cooling host to input coolant into the inner cavity through the first pipe and the first liquid port, and the coolant in the inner cavity returns to the liquid cooling host through the second liquid port and the second pipe; When the level sensor detects that the coolant level in the inner cavity reaches the low level, the controller closes the second electric valve and keeps the first electric valve open. When the level sensor detects that the coolant level in the inner cavity rises to the middle level, the controller opens the second electric valve. When the level sensor detects that the coolant level in the inner cavity reaches the high level, the controller closes the first electric valve and keeps the second electric valve open. When the level sensor detects that the coolant level in the inner cavity drops to the middle level, the controller opens the first electric valve.

[0019] Furthermore, when the immersion liquid-cooled energy storage system includes multiple battery packs, the first liquid port of each battery pack is connected to the first pipeline, and the second liquid port is connected to the second pipeline, so that multiple battery packs are arranged in parallel to form a battery module; In the liquid injection mode, the controller controls the opening of the first and second electric valves of all battery packs, and controls the liquid cooling host to input coolant into the second liquid port of each battery pack through the second pipeline; when the liquid level sensor in one or more battery packs detects that the coolant level in the inner cavity reaches the median height, the controller correspondingly closes the first and second electric valves of this one or more battery packs, and correspondingly reduces the flow rate of the liquid cooling host, until the liquid level sensor in all battery packs detects that the coolant level in the inner cavity has reached the median height, the controller controls the liquid cooling host to shut down; In the refrigeration cycle mode, the controller controls the opening of the first and second electric valves of all battery packs, and controls the liquid cooling host to input coolant into the first liquid port of each battery pack through the first pipeline, so that the coolant in the inner cavity of each battery pack returns to the liquid cooling host through the second liquid port and the second pipeline; when the liquid level sensor in one or more battery packs detects that the coolant level in the inner cavity reaches the low level, the controller correspondingly closes the second electric valve of this one or more battery packs and keeps the first electric valve of this one or more battery packs open; when the liquid level sensor in one or more battery packs detects that the coolant level in the inner cavity rises to the middle level, the controller correspondingly opens the second electric valve of this one or more battery packs. When the level sensor in one or more of the battery packs detects that the coolant level in the cavity has reached the high level, the controller closes the first electric valve of the battery pack while keeping the second electric valve of the battery pack open, and reduces the flow rate of the liquid cooling unit accordingly. When the level sensor in one or more of the battery packs detects that the coolant level in the cavity has dropped to the middle level, the controller opens the first electric valve of the battery pack and increases the flow rate of the liquid cooling unit accordingly.

[0020] Furthermore, in the liquid injection mode, the number of battery packs whose internal coolant level reaches the median height is a, and the required liquid injection flow rate when the internal coolant level in each battery pack reaches the median height is n. At this time, the flow rate reduction of the liquid cooling host is a×n. In the refrigeration cycle mode, the number of battery packs whose coolant level in the inner cavity reaches the high level is b, and the required injection flow rate when the coolant level in the inner cavity of each battery pack reaches the middle level is n. At this time, the flow rate reduction of the liquid cooling host is b×n. When the liquid level sensors of the n battery packs detect that the coolant level in the inner cavity has dropped to the median height, the flow rate of the liquid cooling host increases by b×n.

[0021] Furthermore, the control method for the submerged liquid-cooled energy storage system also includes: In the liquid injection mode, the liquid level sensor in each battery pack first monitors the liquid level of the coolant in the cavity. When the liquid level of the coolant in all battery packs is at the low level, the controller controls the first and second electric valves of all battery packs to open, and controls the liquid cooling host to input coolant into the second liquid port of each battery pack through the second pipeline. When the liquid level of the coolant in one or more battery packs is not at the low level, the controller issues an alarm signal. In the cooling cycle mode, the liquid level sensor in each battery pack first monitors the liquid level of the coolant in the cavity. When the liquid level of the coolant in all battery packs is at the median level, the controller controls the first and second electric valves of all battery packs to open, and controls the liquid cooling host to input coolant into the first liquid port of each battery pack through the first pipeline, so that the coolant in the cavity of each battery pack returns to the liquid cooling host through the second liquid port and the second pipeline. When the liquid level of the coolant in one or more battery packs is not at the median level, the controller issues an alarm signal.

[0022] By adopting the above technical solution, the control method of the immersion liquid-cooled energy storage system of the present invention has at least the following beneficial effects: By using the control method for the submerged liquid-cooled energy storage system to control the aforementioned submerged liquid-cooled energy storage system, the control method for the submerged liquid-cooled energy storage system has all the advantages of the aforementioned submerged liquid-cooled energy storage system, which will not be elaborated here. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the battery pack structure in the immersion liquid-cooled energy storage system provided in an embodiment of the present invention; Figure 2 One of the structural schematic diagrams of the immersion liquid-cooled energy storage system provided in the embodiment of the present invention (the liquid-cooled host is in liquid injection mode). Figure 3 Control logic diagram of the immersion liquid-cooled energy storage system control method provided in the embodiment of the present invention (liquid-cooled host is in liquid injection mode). Figure 4 One of the structural schematic diagrams of the immersion liquid-cooled energy storage system provided in the embodiment of the present invention (the liquid-cooled host is in refrigeration cycle mode). Figure 5 The control logic diagram of the immersion liquid-cooled energy storage system control method provided in the embodiment of the present invention (the liquid-cooled host is in refrigeration cycle mode).

[0025] Figure label: 100 - Battery module; 110 - Battery pack; 120 - Inner cavity; 130 - First electric valve; 140 - Second electric valve; 150 - First liquid port; 160 - Second liquid port; 200-Controller; 300-Liquid-cooled main unit; 400-Level Sensor; 500 - First pipeline; 600 - Second pipeline; 700 - First communication line; 800 - Second communication line; 900 - Third communication line. Detailed Implementation

[0026] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] Please see Figure 2 This embodiment provides an immersion liquid-cooled energy storage system, which includes a battery pack 110, a controller 200, and a liquid-cooled host 300. It should be noted that the liquid-cooled host 300 is prior art, and it is equipped with a compressor, condenser, expansion valve, and circulation pump (not shown in the figure) for cooling and circulating the coolant.

[0030] Please see Figure 1 The battery pack 110 is provided with an inner cavity 120 and a first liquid port 150 and a second liquid port 160, both of which are connected to the inner cavity 120. The inner cavity 120 is used to accommodate the battery and inject coolant so that the battery is directly immersed in the coolant. The first liquid port 150 is provided with a first electric valve 130, and the second liquid port 160 is provided with a second electric valve 140. The first electric valve 130 is used to control the opening or closing of the first liquid port 150, and the second electric valve 140 is used to control the opening or closing of the second liquid port 160. For example, the first electric valve 130 and the second electric valve 140 are preferably normally closed solenoid valves, and their on / off state is controlled by the controller 200 sending an electrical signal. A liquid level sensor 400 for monitoring the coolant level is provided in the inner cavity 120.

[0031] The liquid cooling unit 300 has a switchable liquid injection mode and a refrigeration cycle mode. The liquid cooling unit 300 is connected to the first liquid port 150 via a first pipe 500 and to the second liquid port 160 via a second pipe 600. The liquid level sensor 400, the first electric valve 130, the second electric valve 140, and the liquid cooling unit 300 are all electrically connected to the controller 200. For example, please refer to... Figure 2 The first electric valve 130 and the second electric valve 140 are both electrically connected to the controller 200 via the first communication line 700. The liquid level sensor 400 is electrically connected to the controller 200 via the second communication line 800. The liquid cooling host 300 is electrically connected to the controller 200 via the third communication line 900.

[0032] Controller 200 is configured as follows: In liquid injection mode, the control liquid cooling host 300 inputs coolant into the inner cavity 120 through the second pipe 600 and the second liquid port 160, and opens and closes the first electric valve 130 and the second electric valve 140 of the battery pack 110 according to the liquid level height monitored by the liquid level sensor 400. In cooling cycle mode, the control liquid cooling host 300 inputs coolant into the inner cavity 120 through the first pipe 500 and the first liquid port 150, and the coolant in the inner cavity 120 returns to the liquid cooling host 300 through the second liquid port 160 and the second pipe 600, and opens and closes the first electric valve 130 and the second electric valve 140 of the battery pack 110 according to the liquid level height monitored by the liquid level sensor 400.

[0033] In other words, the liquid cooling unit 300 has a first main unit port and a second main unit port. For example, the first main unit port is connected to the first liquid port 150 through the first pipe 500, and the second main unit port is connected to the second liquid port 160 through the second pipe 600. The first main unit port can be a water outlet, in which case the second main unit port is a water return port, or the first main unit port can be a water return port, in which case the second main unit port is a water outlet.

[0034] In other words, this invention does not limit the first and second main ports to a fixed one-to-one correspondence with the outlet and return ports of the liquid cooling unit 300. It is sufficient that in the liquid injection mode, the coolant enters the inner cavity 120 of the battery pack 110 via the second pipe 600 and the second liquid port 160, and in the cooling cycle mode, the coolant enters the inner cavity 120 of the battery pack 110 via the first pipe 500 and the first liquid port 150. Whether the first and second main ports of the liquid cooling unit 300 are specifically configured as outlets or return ports is determined by the controller 200 adjusting the flow direction switching valve or pump direction inside the liquid cooling unit 300 when switching between the liquid injection mode and the cooling cycle mode.

[0035] It should be noted that the liquid level sensor 400 can be any one of a potentiometric liquid level sensor 400, a float-type liquid level sensor 400, an ultrasonic liquid level sensor 400, or a pressure-type liquid level sensor 400. In this embodiment, the liquid level sensor 400 is preferably a potentiometric liquid level sensor 400. When the liquid level sensor 400 monitors the coolant level in the inner cavity 120 and it reaches a preset median height, this preset median height is the target liquid level during system operation.

[0036] In the initial state, the first electric valve 130 and the second electric valve 140 of the battery pack 110 can both be in the closed state.

[0037] When liquid injection is required, the operator sends an injection command to the controller 200, which then switches the liquid cooling unit 300 to injection mode. Please refer to [link to relevant documentation]. Figure 2 In the liquid injection mode, the controller 200 controls the opening of both the first electric valve 130 and the second electric valve 140 of the battery pack 110, and controls the second host port of the liquid cooling host 300 as the liquid outlet. At this time, the second host port inputs coolant into the inner cavity 120 through the second pipe 600 and the second liquid port 160, so that the coolant level in the inner cavity 120 of the battery pack 110 gradually rises. When the liquid level sensor 400 detects that the coolant level in the inner cavity 120 reaches the preset mid-level height, the first electric valve 130 and the second electric valve 140 of the battery pack 110 are closed accordingly, so that the coolant level in the inner cavity 120 is maintained at the preset mid-level height.

[0038] After the liquid injection is complete, the system can be switched to refrigeration cycle mode for normal operation. Please refer to [link / reference]. Figure 4 In the cooling cycle mode, the controller 200 controls the opening of both the first electric valve 130 and the second electric valve 140 of the battery pack 110, and controls the first host port of the liquid cooling host 300 as the liquid outlet and the second host port as the liquid return port. At this time, the first host port inputs coolant into the inner cavity 120 through the first pipe 500 and the first liquid port 150. After the coolant absorbs heat by flowing over the surface of the submerged battery, it returns to the liquid cooling host 300 through the second liquid port 160 and the second pipe 600 and the second host port.

[0039] During this process, the coolant level inside the cavity 120 of the battery pack 110 is constantly changing: When the level sensor 400 detects that the coolant level in the inner cavity 120 is lower than the preset median height, it closes the second electric valve 140 and keeps the first electric valve 130 open, so that the inner cavity 120 of the battery pack 110 continues to receive coolant but no longer receives coolant. As a result, the coolant level in the inner cavity 120 of the battery pack 110 gradually rises. When the level sensor 400 detects that the coolant level in the inner cavity 120 has risen to the preset median height, it opens the second electric valve 140 to continue cooling the battery in the battery pack 110.

[0040] When the level sensor 400 detects that the coolant level in the inner cavity 120 is higher than the preset median height, it closes the first electric valve 130 and keeps the second electric valve 140 open, so that the inner cavity 120 of the battery pack 110 continues to discharge coolant and no longer discharge coolant. As a result, the coolant level in the inner cavity 120 of the battery pack 110 gradually decreases. When the level sensor 400 detects that the coolant level in the inner cavity 120 has decreased to the preset median height, it opens the first electric valve 130 to continue cooling the battery in the battery pack 110.

[0041] This configuration allows the immersion liquid-cooled energy storage system provided by this invention to monitor the liquid level in real time via a liquid level sensor 400. The controller 200 then automatically controls the two electric valves of the battery pack 110 and the liquid cooling unit 300 to work together, achieving complete automation of the liquid injection and operation processes. The automated liquid injection process eliminates the need for manual observation of the liquid level observation hole or manual valve operation, significantly reducing the difficulty and risk of error associated with manual operation, while improving injection accuracy and efficiency. The automated operation process automatically replenishes liquid when it is too low and automatically drains liquid when it is too high, ensuring that the coolant level in each battery pack 110 is always maintained within a safe range. This effectively reduces the risk of poor battery heat dissipation, temperature rise, or even thermal runaway due to low liquid levels, while also eliminating the safety hazard of coolant overflow due to excessively high liquid levels. Compared to existing technologies that rely on manual observation and inspection, this invention achieves real-time and precise control of the liquid level within the battery pack 110.

[0042] In the above embodiment, the liquid level sensor 400 is used to detect the liquid level height of the coolant in the inner cavity 120 at three signal levels: low, middle, and high. The low level is lower than the middle level, and the high level is higher than the middle level.

[0043] Controller 200 is configured as follows: In the liquid injection mode, the first electric valve 130 and the second electric valve 140 of the control battery pack 110 are both opened, and the control liquid cooling host 300 inputs coolant into the inner cavity 120 through the second pipe 600 and the second liquid port 160; when the liquid level sensor 400 detects that the coolant level in the inner cavity 120 reaches the median height, the first electric valve 130 and the second electric valve 140 of the control battery pack 110 are closed accordingly.

[0044] In the cooling cycle mode, the first electric valve 130 and the second electric valve 140 of the control battery pack 110 are both opened, and the control liquid cooling host 300 is controlled to input coolant into the inner cavity 120 through the first pipe 500 and the first liquid port 150, and the coolant in the inner cavity 120 returns to the liquid cooling host 300 through the second liquid port 160 and the second pipe 600. When the level sensor 400 detects that the coolant level in the inner cavity 120 has reached the low level, it closes the second electric valve 140 while keeping the first electric valve 130 open. When the level sensor 400 detects that the coolant level in the inner cavity 120 has risen to the middle level, it opens the second electric valve 140. When the level sensor 400 detects that the coolant level in the inner cavity 120 has reached the high level, it closes the first electric valve 130 while keeping the second electric valve 140 open. When the level sensor 400 detects that the coolant level in the inner cavity 120 has fallen to the middle level, it opens the first electric valve 130.

[0045] In other words, the liquid level sensor 400 has three detection points set vertically: a low point corresponding to the low liquid level threshold, a middle point corresponding to the middle liquid level threshold, and a high point corresponding to the high liquid level threshold. The middle liquid level threshold is the target liquid level for system operation. The low and high liquid level thresholds constitute the lower and upper limits of the safe liquid level range, respectively. A low level indicates insufficient coolant in the battery pack 110, posing a risk of poor battery heat dissipation or even thermal runaway. A high level indicates excessive coolant in the battery pack 110, posing a risk of coolant overflow.

[0046] With this configuration, the immersion liquid-cooled energy storage system provided by the present invention can detect the liquid level of the coolant in the inner cavity 120 in real time through the liquid level sensor 400 at the low, middle and high signal levels. The controller 200 automatically controls the opening and closing of the first electric valve 130 and the second electric valve 140 according to the liquid level signal, realizing the complete automation of the liquid injection process and the operation process. This effectively reduces the heat dissipation failure or coolant overflow caused by abnormal liquid level, and significantly improves the safety and reliability of the energy storage system.

[0047] In any of the above embodiments, please refer to Figure 2The submersible liquid-cooled energy storage system includes multiple battery packs 110. The first liquid port 150 of each battery pack 110 is connected to the first pipeline 500, and the second liquid port 160 is connected to the second pipeline 600. Thus, the multiple battery packs 110 are arranged in parallel to form a battery module 100.

[0048] Please see Figure 3 In liquid injection mode, when the liquid level sensor 400 in one or more battery packs 110 detects that the coolant level in the inner cavity 120 has reached the median height, the controller 200 correspondingly closes the first electric valve 130 and the second electric valve 140 of the one or more battery packs 110, and correspondingly reduces the flow rate of the liquid cooling host 300 until the liquid level sensor 400 in all battery packs 110 detects that the coolant level in the inner cavity 120 has reached the median height, the controller 200 controls the liquid cooling host 300 to shut down. Please see Figure 5 In the cooling cycle mode, when the liquid level sensor 400 in one or more battery packs 110 detects that the coolant level in the inner cavity 120 has reached the low level, the controller 200 correspondingly closes the second electric valve 140 of the one or more battery packs 110 and keeps the first electric valve 130 of the one or more battery packs 110 open. When the liquid level sensor 400 in one or more battery packs 110 detects that the coolant level in the inner cavity 120 has risen to the middle level, the second electric valve 140 of the one or more battery packs 110 correspondingly opens. When the level sensor 400 in one or more battery packs 110 detects that the coolant level in the inner cavity 120 has reached the high level, the controller 200 correspondingly closes the first electric valve 130 of the one or more battery packs 110, while keeping the second electric valve 140 of the one or more battery packs 110 open, and correspondingly reduces the flow rate of the liquid cooling host 300. When the level sensor 400 in one or more battery packs 110 detects that the coolant level in the inner cavity 120 has dropped to the middle level, the controller 200 correspondingly opens the first electric valve 130 of the one or more battery packs 110, and correspondingly increases the flow rate of the liquid cooling host 300.

[0049] Preferably, please refer to Figure 2 The submersible liquid-cooled energy storage system includes multiple battery modules 100, which are connected in parallel.

[0050] In other words, in the liquid filling mode, the controller 200 continuously monitors the liquid level of each battery pack 110. Whenever one or more battery packs 110 reach the median liquid level, the first electric valve 130 and the second electric valve 140 of the corresponding battery pack 110 are closed, and the total output flow of the liquid cooling unit 300 is reduced accordingly. The reduced flow rate is equal to the sum of the rated flow rates of the closed battery packs 110. The controller 200 shuts down the liquid cooling unit 300 when the coolant level in all battery packs 110 reaches the median height, thus completing the liquid filling mode.

[0051] In the cooling cycle mode, the liquid level sensor 400 in each battery pack 110 monitors the liquid level height of its respective inner cavity 120 in real time and uploads it to the controller 200. When the liquid level of one or more battery packs 110 drops to a low level or rises to a high level, the controller 200 controls the opening and closing of the second electric valve 140 and the first electric valve 130 to gradually raise or lower the liquid level back to the middle level. Then, the controller reopens the second electric valve 140 or the first electric valve 130, thereby dynamically maintaining the liquid level of each battery pack 110 at a stable level near the middle level, ensuring that all battery packs 110 dissipate heat evenly and without the risk of overflow.

[0052] In summary, the immersion liquid-cooled energy storage system provided by the present invention achieves fully automatic liquid injection and operation liquid level regulation in the scenario of multiple battery packs 110 connected in parallel by independently configuring a liquid level sensor 400 and a first electric valve 130 and a second electric valve 140 for each battery pack 110, and by having the controller 200 independently control the opening and closing of each electric valve and the output flow of the liquid cooling host 300 according to the liquid level signal of each battery pack 110.

[0053] In any of the above embodiments, the battery pack 110 is provided with a pressure relief port communicating with the inner cavity 120, and a two-way ventilated pressure relief valve is provided at the pressure relief port.

[0054] It should be noted that the pressure relief port can be located on the top or side wall of the battery pack 110, as long as it can communicate with the top gas phase region of the inner cavity 120. Preferably, the pressure relief port is located on the top of the battery pack 110 to facilitate gas accumulation and discharge.

[0055] This bidirectional ventilated pressure relief valve allows gas to pass through in both directions: when the pressure inside the inner cavity 120 is higher than the external atmospheric pressure, gas can be discharged outward through the pressure relief port; when the pressure inside the inner cavity 120 is lower than the external atmospheric pressure, outside air can enter the inner cavity 120 through the pressure relief port, thus maintaining a pressure balance inside and outside the inner cavity 120. Simultaneously, this bidirectional ventilated pressure relief valve also acts as a seal for the coolant, effectively preventing coolant leakage from the pressure relief port.

[0056] In addition, in the liquid injection mode, as the coolant is injected into the inner cavity 120 from the second liquid port 160, the air in the inner cavity 120 is compressed by the coolant and discharged through the two-way breathable pressure relief valve at the top, ensuring smooth liquid injection and avoiding air resistance in the inner cavity 120.

[0057] During operation in the refrigeration cycle mode, the opening and closing states of the first electric valve 130 and / or the second electric valve 140 change when the system is adjusted to a low or high level. For example, during low-level adjustment, the second electric valve 140 is closed while the first electric valve 130 remains open, allowing coolant to continuously enter but not exit, causing the liquid level in the inner cavity 120 to rise, compressing the upper gas, and potentially increasing the pressure. During high-level adjustment, the first electric valve 130 is closed while the second electric valve 140 remains open, allowing coolant to continuously exit but not enter, causing the liquid level in the inner cavity 120 to drop, expanding the upper gas volume, and potentially decreasing the pressure. At this time, the bidirectional ventilated pressure relief valve automatically opens to vent or intake air, regulating the pressure in the inner cavity 120. This prevents abnormal increases or decreases in pressure within the inner cavity 120 due to the closure of the electric valve, effectively protecting the structural integrity of the battery pack 110 and the safe operation of the internal batteries.

[0058] In any of the above embodiments, please refer to Figure 1 The first liquid outlet 150 is located at the top or near the top of the battery pack 110, and the second liquid outlet 160 is located at the bottom or near the bottom of the battery pack 110.

[0059] For example, the first liquid outlet 150 is disposed on the top cover or upper side wall of the battery pack 110, so that the first liquid outlet 150 is connected to the top area of ​​the inner cavity 120, and the second liquid outlet 160 is disposed on the bottom or lower side wall of the battery pack 110, so that the second liquid outlet 160 is connected to the bottom area of ​​the inner cavity 120.

[0060] In this configuration, during the injection mode, coolant enters the inner cavity 120 through the second inlet 160 located at the bottom. The coolant is injected from the bottom, gradually filling the inner cavity 120 from bottom to top. This smoothly compresses the air within the inner cavity 120 upwards, allowing it to be discharged through the first inlet 150 and the first pipe 500 at the top, or through the pressure relief valve at the top. This bottom-inlet and top-outlet method helps reduce air resistance and air bubbles generated during the injection process, ensuring smooth and complete injection.

[0061] In the cooling cycle mode, the coolant enters the inner cavity 120 through the first liquid inlet 150 located at the top, sprays onto the battery surface from the top, absorbs heat, and then flows downwards by gravity, finally flowing out from the second liquid inlet 160 located at the bottom. This top-inlet and bottom-outlet circulation method allows the coolant to flow evenly across the surface of each battery, achieving sufficient heat exchange, while using gravity-assisted return to reduce the energy consumption of the circulation pump.

[0062] It is understood that the positions of the first liquid outlet 150 and the second liquid outlet 160 are not strictly limited to the absolute top and bottom. As long as the first liquid outlet 150 is higher than the second liquid outlet 160 in the vertical direction, and the first liquid outlet 150 is close to the top for liquid inlet / venting, and the second liquid outlet 160 is close to the bottom for liquid inlet / outlet, the technical effect of the present invention can be achieved.

[0063] The present invention also provides a control method for an immersion liquid-cooled energy storage system, used to control the aforementioned immersion liquid-cooled energy storage system. The control method for the immersion liquid-cooled energy storage system includes: Please see Figure 2 In the liquid injection mode, the controller 200 controls the liquid cooling host 300 to input coolant into the inner cavity 120 of the battery pack 110 through the second pipe 600 and the second liquid port 160, and according to the liquid level height of the coolant in the inner cavity 120 monitored by the liquid level sensor 400 in the battery pack 110, the first electric valve 130 and the second electric valve 140 of the battery pack 110 are opened and closed accordingly.

[0064] Please see Figure 4 In the cooling cycle mode, the controller 200 controls the liquid cooling host 300 to input coolant into the inner cavity 120 of the battery pack 110 through the first pipe 500 and the first liquid port 150, and the coolant in the inner cavity 120 returns to the liquid cooling host 300 through the second liquid port 160 and the second pipe 600. According to the liquid level height of the coolant in the inner cavity 120 monitored by the liquid level sensor 400 in the battery pack 110, the controller opens and closes the first electric valve 130 and the second electric valve 140 of the battery pack 110 accordingly.

[0065] For example, the liquid level sensor 400 is used to detect the liquid level height of the coolant in the inner cavity 120 at three signal levels: low, middle, and high. The low level is lower than the middle level, and the high level is higher than the middle level.

[0066] Please see Figure 3 In the liquid injection mode, the controller 200 controls the opening of both the first electric valve 130 and the second electric valve 140 of the battery pack 110, and controls the liquid cooling host 300 to input coolant into the inner cavity 120 through the second pipe 600 and the second liquid port 160; when the liquid level sensor 400 detects that the coolant level in the inner cavity 120 reaches the median height, the controller 200 correspondingly closes the first electric valve 130 and the second electric valve 140 of the battery pack 110.

[0067] Please see Figure 5In the cooling cycle mode, the controller 200 controls the first electric valve 130 and the second electric valve 140 of the battery pack 110 to open, and controls the liquid cooling host 300 to input coolant into the inner cavity 120 through the first pipe 500 and the first liquid port 150, and the coolant in the inner cavity 120 returns to the liquid cooling host 300 through the second liquid port 160 and the second pipe 600.

[0068] When the level sensor 400 detects that the coolant level in the inner cavity 120 has reached the low level, the controller 200 closes the second electric valve 140 and keeps the first electric valve 130 open. When the level sensor 400 detects that the coolant level in the inner cavity 120 has risen to the middle level, the controller 200 opens the second electric valve 140. When the level sensor 400 detects that the coolant level in the inner cavity 120 has reached the high level, the controller 200 closes the first electric valve 130 and keeps the second electric valve 140 open. When the level sensor 400 detects that the coolant level in the inner cavity 120 has dropped to the middle level, the controller 200 opens the first electric valve 130.

[0069] This configuration allows the immersion liquid-cooled energy storage system provided by this invention to monitor the liquid level in real time via a liquid level sensor 400. The controller 200 then automatically controls the two electric valves of the battery pack 110 and the liquid cooling unit 300 to work together, achieving complete automation of the liquid injection and operation processes. The automated liquid injection process eliminates the need for manual observation of the liquid level observation hole or manual valve operation, significantly reducing the difficulty and risk of error associated with manual operation, while improving injection accuracy and efficiency. The automated operation process automatically replenishes liquid when it is too low and automatically drains liquid when it is too high, ensuring that the coolant level in each battery pack 110 is always maintained within a safe range. This effectively reduces the risk of poor battery heat dissipation, temperature rise, or even thermal runaway due to low liquid levels, while also eliminating the safety hazard of coolant overflow due to excessively high liquid levels. Compared to existing technologies that rely on manual observation and inspection, this invention achieves real-time and precise control of the liquid level within the battery pack 110.

[0070] The immersion liquid-cooled energy storage system provided by the invention uses a liquid level sensor 400 to detect the liquid level of the coolant in the inner cavity 120 in real time at three signal levels: low, middle, and high. The controller 200 automatically controls the opening and closing of the first electric valve 130 and the second electric valve 140 based on the liquid level signal, realizing the complete automation of the liquid injection process and the operation process. This effectively reduces heat dissipation failure or coolant overflow caused by abnormal liquid level, and significantly improves the safety and reliability of the energy storage system.

[0071] Please see Figure 2When the immersion liquid-cooled energy storage system includes multiple battery packs 110, the first liquid port 150 of each battery pack 110 is connected to the first pipeline 500, and the second liquid port 160 is connected to the second pipeline 600, so that multiple battery packs 110 are arranged in parallel to form a battery module 100.

[0072] Please see below. Figure 3 In the liquid injection mode, the controller 200 controls the opening of the first electric valve 130 and the second electric valve 140 of all battery packs 110, and controls the liquid cooling host 300 to input coolant into the second liquid port 160 of each battery pack 110 through the second pipeline 600; when the liquid level sensor 400 in one or more battery packs 110 detects that the coolant level in the inner cavity 120 reaches the median height, the controller 200 correspondingly closes the first electric valve 130 and the second electric valve 140 of this one or more battery packs 110, and correspondingly reduces the flow rate of the liquid cooling host 300 until the liquid level sensor 400 in all battery packs 110 detects that the coolant level in the inner cavity 120 has reached the median height, the controller 200 controls the liquid cooling host 300 to shut down; Please see Figure 5 In the cooling cycle mode, the controller 200 controls the opening of the first electric valve 130 and the second electric valve 140 of all battery packs 110, and controls the liquid cooling host 300 to input coolant into the first liquid port 150 of each battery pack 110 through the first pipe 500, so that the coolant in the inner cavity 120 of each battery pack 110 returns to the liquid cooling host 300 through the second liquid port 160 and the second pipe 600. When the liquid level sensor 400 in one or more battery packs 110 detects that the coolant level in the inner cavity 120 reaches the low level, the controller 200 correspondingly closes the second electric valve 140 of the one or more battery packs 110, and keeps the first electric valve 130 of the one or more battery packs 110 open. When the liquid level sensor 400 in one or more battery packs 110 detects that the coolant level in the inner cavity 120 rises to the middle level, the controller correspondingly opens the second electric valve 140 of the one or more battery packs 110.

[0073] When the level sensor 400 in one or more battery packs 110 detects that the coolant level in the inner cavity 120 has reached the high level, the controller 200 correspondingly closes the first electric valve 130 of the one or more battery packs 110, while keeping the second electric valve 140 of the one or more battery packs 110 open, and correspondingly reduces the flow rate of the liquid cooling host 300. When the level sensor 400 in one or more battery packs 110 detects that the coolant level in the inner cavity 120 has dropped to the middle level, the controller 200 correspondingly opens the first electric valve 130 of the one or more battery packs 110, and correspondingly increases the flow rate of the liquid cooling host 300.

[0074] In summary, the immersion liquid-cooled energy storage system provided by the present invention achieves fully automatic liquid injection and operation liquid level regulation in the scenario of multiple battery packs 110 connected in parallel by independently configuring a liquid level sensor 400 and a first electric valve 130 and a second electric valve 140 for each battery pack 110, and by having the controller 200 independently control the opening and closing of each electric valve and the output flow of the liquid cooling host 300 according to the liquid level signal of each battery pack 110.

[0075] In any of the above embodiments, in the liquid injection mode, the number of battery packs 110 whose coolant level in the inner cavity 120 reaches the median height is a, and the required liquid injection flow rate when the coolant level in the inner cavity 120 of each battery pack 110 reaches the median height is n. At this time, the flow rate reduction of the liquid cooling host 300 is a×n.

[0076] In the cooling cycle mode, the number of battery packs 110 whose coolant level in the inner cavity 120 reaches the high level is b, and the required injection flow rate when the coolant level in the inner cavity 120 of each battery pack 110 reaches the middle level is n. At this time, the flow rate reduction of the liquid cooling host 300 is b×n. When the level sensors 400 of these n battery packs 110 detect that the coolant level in the inner cavity 120 has dropped to the middle level, the flow rate increase of the liquid cooling host 300 is b×n.

[0077] In other words, n is the rated liquid injection flow rate per battery pack 110. The controller 200 has the rated liquid injection flow rate n for each battery pack 110 built in. This rated liquid injection flow rate n refers to the volumetric flow rate of coolant required to fill the inner cavity 120 of a single battery pack 110 from an empty state to the mid-level height per unit time. This value can be pre-calibrated and stored in the controller 200 based on parameters such as the volume of the inner cavity 120 of the battery pack 110 and the pipeline resistance.

[0078] In liquid injection mode, as the liquid injection process proceeds, when the liquid level sensor 400 in some battery packs 110 detects that the coolant level in their inner cavity 120 has reached the median height, the controller 200 closes the first electric valve 130 and the second electric valve 140 of that battery pack 110, stopping the liquid injection. At this time, if the number of battery packs 110 reaching the median height is 'a', then the reduction in flow rate of the liquid cooling host 300 is 'a×n'.

[0079] Through the above flow control strategy, the output flow of the liquid cooling host 300 is always matched with the number of battery packs 110 that are not yet fully filled, which avoids energy waste caused by excess flow and ensures that the liquid filling speed of the remaining unfilled battery packs 110 is not affected.

[0080] In the cooling cycle mode, when the level sensor 400 in some battery packs 110 detects that the coolant level in their inner cavity 120 has risen to the high level, the controller 200 closes the first electric valve 130 of that battery pack 110 while keeping the second electric valve 140 open, causing the battery pack 110 to stop receiving coolant and continue receiving coolant, thus gradually lowering its coolant level. At this time, since some battery packs 110 stop receiving coolant, the total amount of coolant entering the system decreases, and the controller 200 correspondingly reduces the output flow of the liquid cooling unit 300 to avoid unnecessary energy consumption. Specifically, if the number of battery packs 110 with a coolant level reaching the high level is b, then the reduction in the flow of the liquid cooling unit 300 is b×n. When the coolant level of these battery packs 110 gradually decreases and returns to the middle level, the controller 200 reopens its first electric valve 130 and correspondingly increases the output flow of the liquid cooling unit 300 by the same amount, b×n.

[0081] Through the above-mentioned flow segmentation control strategy based on the number of battery packs 110, the present invention achieves precise matching between the output flow of the liquid cooling host 300 and the actual needs of each battery pack 110, avoiding excessive or insufficient flow, effectively reducing system energy consumption, and ensuring the response speed and accuracy of liquid level adjustment for each battery pack 110.

[0082] In any of the above embodiments, the control method for the submerged liquid-cooled energy storage system further includes: Please see Figure 3 In the liquid injection mode, the liquid level sensor 400 in each battery pack 110 first monitors the liquid level of the coolant in the inner cavity 120. When the liquid level of the coolant in all battery packs 110 is at a low level, the controller 200 controls the first electric valve 130 and the second electric valve 140 of all battery packs 110 to open, and controls the liquid cooling host 300 to input coolant into the second liquid port 160 of each battery pack 110 through the second pipeline 600. When the liquid level of the coolant in one or more battery packs 110 is not at a low level, the controller 200 issues an alarm signal.

[0083] Please see Figure 5In the cooling cycle mode, the liquid level sensor 400 in each battery pack 110 first monitors the liquid level of the coolant in the inner cavity 120. When the liquid level of the coolant in all battery packs 110 is at the median level, the controller 200 controls the first electric valve 130 and the second electric valve 140 of all battery packs 110 to open, and controls the liquid cooling host 300 to input coolant into the first liquid port 150 of each battery pack 110 through the first pipe 500, so that the coolant in the inner cavity 120 of each battery pack 110 returns to the liquid cooling host 300 through the second liquid port 160 and the second pipe 600. When the liquid level of the coolant in one or more battery packs 110 is not at the median level, the controller 200 issues an alarm signal.

[0084] In other words, when the system receives the liquid injection command, the controller 200 first executes the pre-start self-test program to ensure that each battery pack 110 is in an initial state suitable for liquid injection.

[0085] Specifically, before the liquid injection mode is activated, the controller 200 monitors the liquid level of the coolant in the cavity 120 of each battery pack 110 through the liquid level sensor 400 in each battery pack 110. The controller 200 determines whether the liquid level of the coolant in all battery packs 110 is at the low level.

[0086] When the coolant level in all battery packs 110 is at the low level, it indicates that the coolant in each battery pack 110 has been drained or is at the minimum safe level, and the conditions for adding coolant are met. At this time, the controller 200 determines that the system status is normal, allows the start of the coolant filling mode, and begins the coolant filling process.

[0087] When the coolant level in one or more battery packs 110 is not at the low level, it indicates that there is residual coolant in the battery pack 110, possibly due to incomplete drainage or leakage during the previous operation, making it unsafe to add coolant. In this case, the controller 200 determines that the system status is abnormal, prohibits the start of the coolant filling mode, and issues an alarm signal. This alarm signal can be an audible and visual alarm or an alarm message sent to the host computer monitoring system, used to prompt the operator to check and handle the situation. The operator can only restart the coolant filling mode after troubleshooting the abnormality.

[0088] In addition, when the system completes liquid injection and receives the refrigeration cycle start command, the controller 200 also executes a pre-start self-test program to ensure that each battery pack 110 is in a standard state suitable for operation.

[0089] Specifically, before the cooling cycle mode is started, the controller 200 monitors the coolant level in the cavity 120 of each battery pack 110 through the liquid level sensor 400 in each battery pack 110, and the controller 200 determines whether the coolant level in all battery packs 110 is at the median level.

[0090] When the coolant level in all battery packs 110 is at the median level, it indicates that the coolant level in each battery pack 110 has precisely reached the target level for system operation, and the conditions for normal start-up of the cooling cycle are met. At this time, the controller 200 determines that the system status is normal, allows the start of the cooling cycle mode, and begins cooling cycle operation.

[0091] When the coolant level in one or more battery packs 110 is not at the median level, it indicates that the coolant level in that battery pack 110 deviates from the target value, possibly due to insufficient filling, leakage, or excessive filling, and the conditions for safely starting the cooling cycle are not met. In this case, the controller 200 determines that the system status is abnormal, prohibits the start of the cooling cycle mode, and issues an alarm signal. The operator can only restart the cooling cycle mode after checking and adjusting the abnormal battery pack 110 according to the alarm information.

[0092] This setup automatically detects the liquid level of each battery pack 110 before the system starts, ensuring that all battery packs 110 are in the initial liquid level condition suitable for the current working mode, avoiding safety risks caused by abnormal liquid level startup, and automatically determines whether startup is allowed through a self-test program, avoiding safety hazards caused by human error.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions 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 invention.

Claims

1. An immersion liquid-cooled energy storage system, characterized in that, Includes a battery pack (110), a controller (200), and a liquid-cooled main unit (300). The battery pack (110) is provided with an inner cavity (120) and a first liquid port (150) and a second liquid port (160) both communicating with the inner cavity (120). The first liquid port (150) is provided with a first electric valve (130), and the second liquid port (160) is provided with a second electric valve (140). A liquid level sensor (400) for monitoring the liquid level of the coolant is provided in the inner cavity (120). The liquid cooling host (300) has a switchable liquid injection mode and a cooling cycle mode, and the liquid cooling host (300) is connected to the first liquid port (150) through the first pipe (500) and to the second liquid port (160) through the second pipe (600); The liquid level sensor (400), the first electric valve (130), the second electric valve (140) and the liquid cooling host (300) are all electrically connected to the controller (200); The controller (200) is configured as follows: In the liquid injection mode, the liquid cooling host (300) is controlled to input coolant into the inner cavity (120) through the second pipeline (600) and the second liquid port (160), and the first electric valve (130) and the second electric valve (140) of the battery pack (110) are opened and closed accordingly based on the liquid level height of the coolant in the inner cavity (120) monitored by the liquid level sensor (400). In the refrigeration cycle mode, the liquid cooling host (300) is controlled to input coolant into the inner cavity (120) through the first pipe (500) and the first liquid port (150), and the coolant in the inner cavity (120) returns to the liquid cooling host (300) through the second liquid port (160) and the second pipe (600). The first electric valve (130) and the second electric valve (140) of the battery pack (110) are opened and closed accordingly based on the liquid level height of the coolant in the inner cavity (120) monitored by the liquid level sensor (400).

2. The immersion liquid-cooled energy storage system according to claim 1, characterized in that, The liquid level sensor (400) is used to detect the liquid level height of the coolant in the inner cavity (120) at three signal levels: low, middle and high. The low level is lower than the middle level and the high level is higher than the middle level. The controller (200) is configured as follows: In the liquid injection mode, the first electric valve (130) and the second electric valve (140) of the battery pack (110) are both opened, and the liquid cooling host (300) is controlled to input coolant into the inner cavity (120) through the second pipeline (600) and the second liquid port (160); when the liquid level sensor (400) detects that the coolant level in the inner cavity (120) reaches the median height, the first electric valve (130) and the second electric valve (140) of the battery pack (110) are closed accordingly. In the refrigeration cycle mode, the first electric valve (130) and the second electric valve (140) of the battery pack (110) are both opened, and the liquid cooling host (300) is controlled to input coolant into the inner cavity (120) through the first pipe (500) and the first liquid port (150), and the coolant in the inner cavity (120) is returned to the liquid cooling host (300) through the second liquid port (160) and the second pipe (600). When the liquid level sensor (400) detects that the coolant level in the inner cavity (120) reaches the low level, the second electric valve (140) is closed accordingly, while the first electric valve (130) remains open. When the liquid level sensor (400) detects that the coolant level in the inner cavity (120) rises to the middle level, the second electric valve (140) is opened accordingly. When the liquid level sensor (400) detects that the coolant level in the inner cavity (120) reaches the high level, the first electric valve (130) is closed and the second electric valve (140) is kept open. When the liquid level sensor (400) detects that the coolant level in the inner cavity (120) drops to the middle level, the first electric valve (130) is opened.

3. The immersion liquid-cooled energy storage system according to claim 2, characterized in that, The immersion liquid-cooled energy storage system includes multiple battery packs (110), with the first liquid port (150) of each battery pack (110) connected to the first pipeline (500) and the second liquid port (160) connected to the second pipeline (600), thereby the multiple battery packs (110) are arranged in parallel to form a battery module (100). In the liquid injection mode, when the liquid level sensor (400) in one or more of the battery packs (110) detects that the coolant level in the inner cavity (120) has reached the median height, the controller (200) correspondingly closes the first electric valve (130) and the second electric valve (140) of the one or more battery packs (110), and correspondingly reduces the flow rate of the liquid cooling host (300) until the liquid level sensor (400) in all the battery packs (110) detects that the coolant level in the inner cavity (120) has reached the median height, the controller (200) controls the liquid cooling host (300) to shut down; In the cooling cycle mode, when the liquid level sensor (400) in one or more of the battery packs (110) detects that the coolant level in the inner cavity (120) reaches the low level, the controller (200) correspondingly closes the second electric valve (140) of the one or more battery packs (110) and keeps the first electric valve (130) of the one or more battery packs (110) open. When the liquid level sensor (400) in one or more of the battery packs (110) detects that the coolant level in the inner cavity (120) rises to the middle level, the second electric valve (140) of the one or more battery packs (110) correspondingly opens. When the liquid level sensor (400) in one or more of the battery packs (110) detects that the coolant level in the inner cavity (120) reaches the high level, the controller (200) correspondingly closes the first electric valve (130) of the one or more battery packs (110) and keeps the second electric valve (140) of the one or more battery packs (110) open, and correspondingly reduces the flow rate of the liquid cooling host (300). When the liquid level sensor (400) in one or more of the battery packs (110) detects that the coolant level in the inner cavity (120) drops to the middle level, the controller correspondingly opens the first electric valve (130) of the one or more battery packs (110) and correspondingly increases the flow rate of the liquid cooling host (300).

4. The immersion liquid-cooled energy storage system according to any one of claims 1-3, characterized in that, The battery pack (110) is provided with a pressure relief port that communicates with the inner cavity (120), and a two-way ventilated pressure relief valve is provided at the pressure relief port.

5. The immersion liquid-cooled energy storage system according to any one of claims 1-3, characterized in that, The first liquid outlet (150) is located at the top or near the top of the battery pack (110), and the second liquid outlet (160) is located at the bottom or near the bottom of the battery pack (110).

6. A control method for an immersion liquid-cooled energy storage system, characterized in that, The method for controlling the submerged liquid-cooled energy storage system according to any one of claims 1-5, wherein the control method for the submerged liquid-cooled energy storage system comprises: In the liquid injection mode, the controller (200) controls the liquid cooling host (300) to input coolant into the inner cavity (120) of the battery pack (110) through the second pipeline (600) and the second liquid port (160), and according to the liquid level height of the coolant in the inner cavity (120) monitored by the liquid level sensor (400) in the battery pack (110), the first electric valve (130) and the second electric valve (140) of the battery pack (110) are opened and closed accordingly. In the refrigeration cycle mode, the controller (200) controls the liquid cooling host (300) to input coolant into the inner cavity (120) of the battery pack (110) through the first pipe (500) and the first liquid port (150), and the coolant in the inner cavity (120) returns to the liquid cooling host (300) through the second liquid port (160) and the second pipe (600). According to the liquid level height of the coolant in the inner cavity (120) monitored by the liquid level sensor (400) in the battery pack (110), the controller opens and closes the first electric valve (130) and the second electric valve (140) of the battery pack (110) accordingly.

7. The control method for the submerged liquid-cooled energy storage system according to claim 6, characterized in that, The liquid level sensor (400) is used to detect the liquid level height of the coolant in the inner cavity (120) at three signal levels: low, middle and high. The low level is lower than the middle level and the high level is higher than the middle level. In the liquid injection mode, the controller (200) controls both the first electric valve (130) and the second electric valve (140) of the battery pack (110) to open, and controls the liquid cooling host (300) to input coolant into the inner cavity (120) through the second pipeline (600) and the second liquid port (160); when the liquid level sensor (400) detects that the coolant level in the inner cavity (120) reaches the median height, the controller (200) correspondingly closes the first electric valve (130) and the second electric valve (140) of the battery pack (110). In the refrigeration cycle mode, the controller (200) controls the first electric valve (130) and the second electric valve (140) of the battery pack (110) to open, and controls the liquid cooling host (300) to input coolant into the inner cavity (120) through the first pipe (500) and the first liquid port (150), and the coolant in the inner cavity (120) returns to the liquid cooling host (300) through the second liquid port (160) and the second pipe (600). When the liquid level sensor (400) detects that the coolant level in the inner cavity (120) reaches the low level, the controller (200) closes the second electric valve (140) and keeps the first electric valve (130) open. When the liquid level sensor (400) detects that the coolant level in the inner cavity (120) rises to the middle level, the controller (200) opens the second electric valve (140). When the level sensor (400) detects that the coolant level in the inner cavity (120) reaches the high level, the controller (200) closes the first electric valve (130) and keeps the second electric valve (140) open. When the level sensor (400) detects that the coolant level in the inner cavity (120) drops to the middle level, the controller (200) opens the first electric valve (130).

8. The control method for the submerged liquid-cooled energy storage system according to claim 7, characterized in that, When the immersion liquid-cooled energy storage system includes multiple battery packs (110), the first liquid port (150) of each battery pack (110) is connected to the first pipeline (500), and the second liquid port (160) is connected to the second pipeline (600), so that multiple battery packs (110) are arranged in parallel to form a battery module (100). In the liquid injection mode, the controller (200) controls the opening of the first electric valve (130) and the second electric valve (140) of all the battery packs (110), and controls the liquid cooling host (300) to input coolant into the second liquid port (160) of each battery pack (110) through the second pipeline (600); when the liquid level sensor (400) in one or more of the battery packs (110) detects that the coolant level in the inner cavity (120) reaches the median height, the controller (200) correspondingly closes the first electric valve (130) and the second electric valve (140) of this one or more battery packs (110), and correspondingly reduces the flow rate of the liquid cooling host (300) until the liquid level sensor (400) in all the battery packs (110) detects that the coolant level in the inner cavity (120) has reached the median height, the controller (200) controls the liquid cooling host (300) to shut down; In the refrigeration cycle mode, the controller (200) controls the first electric valve (130) and the second electric valve (140) of all the battery packs (110) to open, and controls the liquid cooling host (300) to input coolant into the first liquid port (150) of each battery pack (110) through the first pipe (500), so that the coolant in the inner cavity (120) of each battery pack (110) returns to the liquid cooling host (300) through the second liquid port (160) and the second pipe (600); when the coolant in one or more of the battery packs (110) is... When the level sensor (400) detects that the coolant level in the inner cavity (120) reaches the low level, the controller (200) correspondingly closes the second electric valve (140) of the one or more battery packs (110) and keeps the first electric valve (130) of the one or more battery packs (110) open. When the level sensor (400) in the one or more battery packs (110) detects that the coolant level in the inner cavity (120) rises to the middle level, the controller correspondingly opens the second electric valve (140) of the one or more battery packs (110). When the liquid level sensor (400) in one or more of the battery packs (110) detects that the coolant level in the inner cavity (120) reaches the high level, the controller (200) correspondingly closes the first electric valve (130) of the one or more battery packs (110) and keeps the second electric valve (140) of the one or more battery packs (110) open, and correspondingly reduces the flow rate of the liquid cooling host (300). When the liquid level sensor (400) in one or more of the battery packs (110) detects that the coolant level in the inner cavity (120) drops to the middle level, the controller correspondingly opens the first electric valve (130) of the one or more battery packs (110) and correspondingly increases the flow rate of the liquid cooling host (300).

9. The control method for the submerged liquid-cooled energy storage system according to claim 8, characterized in that, In the liquid injection mode, the number of battery packs (110) whose coolant level in the inner cavity (120) reaches the median height is a, and the liquid injection flow rate required for the coolant level in the inner cavity (120) of each battery pack (110) to reach the median height is n. At this time, the flow rate reduction of the liquid cooling host (300) is a×n. In the refrigeration cycle mode, the number of battery packs (110) whose coolant level in the inner cavity (120) reaches the high height is b, and the required injection flow rate when the coolant level in the inner cavity (120) of each battery pack (110) reaches the middle height is n. At this time, the flow rate reduction of the liquid cooling host (300) is b×n. When the liquid level sensor (400) of the n battery packs (110) detects that the coolant level in the inner cavity (120) has dropped to the median height, the flow rate of the liquid cooling host (300) increases by b×n.

10. The control method for the submerged liquid-cooled energy storage system according to claim 8, characterized in that, The control method for the submerged liquid-cooled energy storage system also includes: In the liquid injection mode, the liquid level sensor (400) in each of the battery packs (110) first monitors the liquid level of the coolant in the inner cavity (120). When the liquid level of the coolant in all the battery packs (110) is low, the controller (200) controls the first electric valve (130) and the second electric valve (140) of all the battery packs (110) to open, and controls the liquid cooling host (300) to input coolant into the second liquid port (160) of each battery pack (110) through the second pipeline (600). When the liquid level of the coolant in one or more of the battery packs (110) is not low, the controller (200) issues an alarm signal. In the cooling cycle mode, the liquid level sensor (400) in each of the battery packs (110) first monitors the liquid level of the coolant in the inner cavity (120). When the liquid level of the coolant in all the battery packs (110) is at the median height, the controller (200) controls the first electric valve (130) and the second electric valve (140) of all the battery packs (110) to open, and controls the liquid cooling host (300) to input coolant into the first liquid port (150) of each battery pack (110) through the first pipeline (500), so that the coolant in the inner cavity (120) of each battery pack (110) returns to the liquid cooling host (300) through the second liquid port (160) and the second pipeline (600). When the liquid level of the coolant in one or more of the battery packs (110) is not at the median height, the controller (200) issues an alarm signal.

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