Immersed liquid-cooled energy storage system, cluster-level control circuit

Abstract

The embodiments of the present disclosure relate to the field of energy storage, and provide an immersion liquid-cooled energy storage system and a cluster-level control circuit. The immersion liquid-cooled energy storage system comprises: at least two cooling units, each of which has a housing for accommodating a battery cluster; at least two sub-liquid inlet pipes and at least two sub-liquid outlet pipes, one sub-liquid outlet pipe and one sub-liquid inlet pipe being respectively connected to the same cooling unit; a cluster-level control unit comprising a gas relay and an electric valve being installed on the sub-liquid outlet pipe and corresponding one to the sub-liquid outlet pipe; the gas relay being configured to send a thermal runaway signal to a system-level controller if a thermal runaway occurs in the battery cluster; the electric valve being configured to open or close a coolant flow path of the sub-liquid outlet pipe corresponding to the electric valve; the battery cluster that sends a thermal runaway signal is taken as a target battery cluster, and the system-level controller is configured to at least receive and control the electric valve corresponding to the target battery cluster to close based on the thermal runaway signal, which is at least conducive to isolating the coolant in a single cooling unit.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the field of energy storage, and in particular to an immersion liquid-cooled energy storage system and a cluster-level control circuit. Background Art

[0002] Large-scale chemical battery energy storage systems such as energy storage power stations, energy storage containers, and industrial and commercial energy storage require the arrangement of energy storage batteries, battery racks, fire protection equipment, electrical integrated cabinets, liquid cooling units, and cooling and dehumidification equipment in a limited space. At present, immersion liquid cooling technology is widely used in the energy storage industry. In order to ensure that lithium-ion batteries operate at a suitable temperature and give full play to the performance of lithium-ion batteries, immersion liquid cooling is usually used to cool lithium-ion batteries.

[0003] However, in the immersion liquid cooling method of the related art, the coolant is usually circulated as a whole. When individual battery cells thermally run away, a large amount of flammable gas and conductive electrolyte are ejected, which will contaminate the coolant. The contaminated coolant will circulate through other battery clusters along the pipeline, thereby contaminating the coolant of the entire energy storage system, easily causing heat diffusion and posing a hidden danger to the entire energy storage system. Summary of the invention

[0004] The embodiments of the present disclosure provide an immersion liquid-cooled energy storage system and a cluster-level control circuit, which are at least conducive to isolating the coolant in a single cooling unit.

[0005] According to some embodiments of the present disclosure, on the one hand, an immersion liquid-cooled energy storage system is provided, comprising: at least two cooling units, the cooling units corresponding one-to-one to battery clusters, the cooling units having a housing for accommodating the battery clusters; at least two sub-liquid inlet pipes, and sub-liquid outlet pipes corresponding one-to-one to the sub-liquid inlet pipes, one sub-liquid outlet pipe and one sub-liquid inlet pipe being connected to the same cooling unit respectively; a cluster-level control unit, mounted on the sub-liquid outlet pipes and corresponding one-to-one to the sub-liquid outlet pipes, the cluster-level control unit comprising a gas relay and an electric valve; the gas relay is configured to send a thermal runaway signal to the system-level controller if thermal runaway occurs in the battery cluster; the electric valve is configured to turn on or off the coolant flow path of the sub-liquid outlet pipe corresponding to the electric valve; a system-level controller is electrically connected to the cluster-level control unit; the battery cluster that sends the thermal runaway signal is taken as the target battery cluster, and the system-level controller is configured to at least receive and control the electric valve corresponding to the target battery cluster to be turned off based on the thermal runaway signal.

[0006] In some embodiments, the gas relay includes a warning relay and an emergency stop relay; the warning relay is configured such that if the accumulated amount of gas in the gas relay reaches a first threshold, the warning switch in the warning relay is closed to send a warning signal to the system-level controller; the emergency stop relay is configured such that if the accumulated amount of gas in the gas relay reaches a second threshold, the emergency stop switch in the emergency stop relay is closed to send a thermal runaway signal to the system-level controller; wherein the first threshold is less than the second threshold.

[0007] In some embodiments, the gas relay has an inner cavity containing coolant, and a float and a baffle are provided in the inner cavity. The float floats with the change of the liquid level of the coolant contained in the inner cavity, and the gas relay is also provided with a magnet, a signal contact and a trip contact; the gas relay is configured that if the float is lowered to a first preset position, the magnet controls the signal contact to be connected to send a warning signal to the system-level controller, and if the baffle is impacted to a second preset position, the magnet controls the trip contact to be connected to send a thermal runaway signal to the system-level controller; with the bottom surface of the inner cavity as the reference plane, the second preset position is lower than the first preset position.

[0008] In some embodiments, the submerged liquid-cooled energy storage system further includes at least two circuit breakers, which are electrically connected to the battery clusters and correspond one-to-one to the battery clusters; the system-level controller is configured to receive and control the circuit breaker corresponding to the target battery cluster to shut down based on the thermal runaway signal so as to cut off the power supply of the target battery cluster.

[0009] In some embodiments, the cooling unit has an upper side and a lower side relative to each other along the height direction of the immersion liquid-cooled energy storage system; among the sub-liquid outlet pipe and the sub-liquid inlet pipe connected to the same cooling unit, the sub-liquid outlet pipe is connected to the upper side, and the sub-liquid inlet pipe is connected to the lower side.

[0010] In some embodiments, the sub-liquid outlet pipe has a first end close to the cooling unit and a second end away from the cooling unit, and the cluster-level control unit is installed on the second end; taking the plane where the lower side is located as a reference plane, a second distance between the second end and the reference plane is greater than the first distance between the first end and the reference plane.

[0011] In some embodiments, the angle between the line between the first end and the second end and the reference plane is 1.5° to 6°.

[0012] In some embodiments, the submerged liquid-cooled energy storage system further includes: a float located on the liquid surface of the coolant contained in the cooling unit, and the float floats as the liquid level of the coolant contained in the cooling unit changes; a float switch is provided in the cooling unit; the float switch is configured such that if the float is lowered to a third preset position, the float switch is closed; the system-level controller is also configured to receive and control the electric valve corresponding to the target battery cluster to be closed based on the thermal runaway signal if the float switch is closed.

[0013] According to some embodiments of the present disclosure, on the other hand, the embodiments of the present disclosure further provide a cluster-level control circuit, which is applied to the immersion liquid-cooled energy storage system described in any of the above items, including: a power supply; an emergency stop switch and a first control switch connected in parallel with the power supply, and the emergency stop switch and the first control switch are connected in series; the emergency stop switch is configured so that if the battery cluster has thermal runaway, the gas relay controls the emergency stop switch to close; the first control switch is configured so that if the battery cluster has thermal runaway, the system-level controller controls the first control switch to close; the electric valve associated with the first control switch, the electric valve is configured to be turned off if the electric valve is electrically connected to the power supply.

[0014] In some embodiments, the cluster-level control circuit further includes: an early warning switch and a second control switch connected in parallel with the power supply, the early warning switch and the second control switch being connected in series; the early warning switch being configured such that if a minor fault occurs in the battery cluster or a minor leakage of the coolant occurs, the gas relay controls the early warning switch to close; the second control switch being configured such that if a minor fault occurs in the battery cluster or a minor leakage of the coolant occurs, the system-level controller controls the second control switch to close; and / or the circuit breaker connected in parallel with the first control switch, the circuit breaker being configured to be turned off if the circuit breaker is electrically connected to the power supply.

[0015] The technical solution provided by the embodiments of the present disclosure has at least the following advantages:

[0016] Each battery cluster is matched with a cooling unit to achieve targeted cooling of any battery cluster. Based on this, a cluster-level control unit is installed on the output path of the coolant in each cooling unit, that is, on the sub-liquid outlet pipe, and the gas relay in the cluster-level control unit is used to monitor whether the battery cluster has thermal runaway. When the battery cluster has thermal runaway, the electric valve in the cluster-level control unit is controlled to shut down with the help of the system-level controller to shut down the coolant flow path of the sub-liquid outlet pipe corresponding to the battery cluster with thermal runaway. In this way, even if the battery cluster with thermal runaway contaminates the coolant of the cooling unit corresponding to it, the cluster-level control unit can be used to prevent the contaminated coolant from flowing to other cooling units based on the sub-liquid outlet pipe. In other words, the coolant in a single cooling unit can be isolated with the help of the cluster-level control unit, that is, the single cluster isolation of the coolant is achieved, and the thermal runaway phenomenon can be prevented from spreading to the entire immersion liquid-cooled energy storage system with the help of the circulation of the coolant, which is conducive to further improving the safety of the immersion liquid-cooled energy storage system.

[0017] In addition, after the coolant is isolated in a single cluster, it is also convenient for operators to perform maintenance on the cooling unit where the coolant is contaminated separately. Since the shutdown of the electric valve will not affect other cooling units, it is easy to achieve single cluster maintenance of the coolant. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings, and these exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise specified, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the traditional technology, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of a first partial cross-sectional structure of an immersion liquid-cooled energy storage system provided in an embodiment of the present disclosure;

[0020] Figure 2 A functional block diagram of a cluster-level control unit and a system-level controller in an immersion liquid-cooled energy storage system provided by an embodiment of the present disclosure;

[0021] Figure 3 A functional block diagram of a gas relay and a system-level controller in an immersion liquid-cooled energy storage system provided by an embodiment of the present disclosure;

[0022] Figure 4 A schematic diagram of a partial cross-sectional structure of a gas relay included in an immersion liquid-cooled energy storage system provided in an embodiment of the present disclosure;

[0023] Figure 5 A functional block diagram of a system-level controller, a circuit breaker, and a battery cluster in an immersion liquid-cooled energy storage system provided by an embodiment of the present disclosure;

[0024] Figure 6 A schematic diagram of a second partial cross-sectional structure of an immersion liquid-cooled energy storage system provided in one embodiment of the present disclosure;

[0025] Figure 7 A schematic diagram of a third partial cross-sectional structure of an immersion liquid-cooled energy storage system provided in one embodiment of the present disclosure;

[0026] Figure 8 A schematic diagram of a fourth partial cross-sectional structure of an immersion liquid-cooled energy storage system provided in an embodiment of the present disclosure;

[0027] Fig. 9 A schematic diagram of a cluster-level control circuit applied to an immersion liquid-cooled energy storage system provided in another embodiment of the present disclosure. DETAILED DESCRIPTION

[0028] As can be seen from the background technology, the problem of coolant contamination in immersion liquid-cooled energy storage systems needs to be solved.

[0029] The present disclosure provides an immersion liquid-cooled energy storage system and a cluster-level control circuit. In the immersion liquid-cooled energy storage system, each battery cluster is matched with a cooling unit to achieve targeted cooling of any battery cluster. Based on this, a cluster-level control unit is installed on the output path of the coolant in each cooling unit, that is, on the sub-liquid outlet pipe, and the gas relay in the cluster-level control unit is used to monitor whether the battery cluster has thermal runaway. When the battery cluster has thermal runaway, the electric valve in the cluster-level control unit is controlled to be closed by the system-level controller to close the coolant flow path of the sub-liquid outlet pipe corresponding to the battery cluster with thermal runaway. In this way, even if the battery cluster with thermal runaway contaminates the coolant of the cooling unit corresponding to it, the cluster-level control unit can be used to prevent the contaminated coolant from flowing to other cooling units based on the sub-liquid outlet pipe. In other words, the coolant in a single cooling unit can be isolated by the cluster-level control unit, that is, the single cluster isolation of the coolant is achieved, and the thermal runaway phenomenon can be prevented from spreading to the entire immersion liquid-cooled energy storage system by the circulation of the coolant, which is conducive to further improving the safety of the immersion liquid-cooled energy storage system. In addition, after the coolant is isolated in a single cluster, it is also convenient for operators to perform maintenance on the cooling unit where the coolant is contaminated separately. Since the shutdown of the electric valve will not affect other cooling units, it is easy to achieve single cluster maintenance of the coolant.

[0030] In the description of the embodiments of the present disclosure, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present disclosure, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0031] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present disclosure. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0032] In the description of the embodiments of the present disclosure, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0033] In the description of the embodiments of the present disclosure, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0034] In the description of the embodiments of the present disclosure, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present disclosure and simplifying the description. They do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the embodiments of the present disclosure.

[0035] In the description of the embodiments of the present disclosure, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to the specific circumstances.

[0036] In the accompanying drawings corresponding to the embodiments of the present disclosure, the thickness and area of ​​the layers are exaggerated for better understanding and ease of description. When describing a component (such as a layer, film, region or substrate) on another component or on the surface of another component, the component may be "directly" located on the surface of the other component, or a third component may exist between the two components. On the contrary, when describing a component on the surface of another component or when another component is formed or provided on the surface of a component, it means that there is no third component between the two components. In addition, when describing a component as being "substantially" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a partial edge of the entire surface.

[0037] In the description of the embodiments of the present disclosure, when a component "includes" another component, unless otherwise specified, other components are not excluded, and other components may be further included. In addition, when a component such as a layer, film, region, or plate is referred to as being "on / located on" another component, it may be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may exist in between. In addition, when a component such as a layer, film, region, or plate is "directly located on" another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it means that no other components are located in between.

[0038] The terms used in the description of the various embodiments described herein are only used to describe specific embodiments and are not intended to be limiting. As used in the description of the various embodiments described and in the appended claims, "the components" are also intended to include plural forms unless the context clearly indicates otherwise. Among them, components include components such as layers, films, regions, or plates.

[0039] The following will describe the various embodiments of the present disclosure in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present disclosure, many technical details are provided in order to enable the reader to better understand the embodiments of the present disclosure. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the embodiments of the present disclosure can be implemented.

[0040] An embodiment of the present disclosure provides an immersion liquid-cooled energy storage system. The immersion liquid-cooled energy storage system provided by an embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0041] Combined with reference Figure 1 and Figure 2The immersion liquid-cooled energy storage system 100 includes: at least two cooling units 101, each cooling unit 101 corresponds to a battery cluster 102, and the cooling unit 101 has a receiving cavity 111 for receiving the battery cluster 102; at least two sub-liquid inlet pipes 113, and sub-liquid outlet pipes 114 corresponding to the sub-liquid inlet pipes 113, and a sub-liquid outlet pipe 114 and a sub-liquid inlet pipe 113 are respectively connected to the same cooling unit 101; a cluster-level control unit 105 is installed on the sub-liquid outlet pipe 114 and corresponds to the sub-liquid outlet pipe 114, and the cluster-level control unit 105 includes a gas relay The gas relay 115 and the electric valve 125; the gas relay 115 is configured to send a thermal runaway signal to the system-level controller 106 if the battery cluster 102 has a thermal runaway; the electric valve 125 is configured to turn on or off the coolant flow path of the sub-liquid outlet pipe 114 corresponding to the electric valve 125; the system-level controller 106 is electrically connected to the cluster-level control unit 105; the battery cluster 102 that sends the thermal runaway signal is taken as the target battery cluster, and the system-level controller 106 is configured to at least receive and control the electric valve 125 corresponding to the target battery cluster to be turned off based on the thermal runaway signal.

[0042] It should be noted that Figure 1 A schematic diagram of a first partial cross-sectional structure of an immersion liquid-cooled energy storage system provided in an embodiment of the present disclosure; Figure 2 A functional block diagram of a cluster-level control unit and a system-level controller in an immersion liquid-cooled energy storage system provided in an embodiment of the present disclosure.

[0043] It is worth noting that in order to improve the energy storage density, the immersion liquid-cooled energy storage system 100 often includes multiple battery clusters 102. Each battery cluster 102 is designed to be surrounded by a cooling unit 101, which not only realizes immersion liquid cooling treatment for each battery cluster 102, but also based on the one-to-one correspondence between the battery cluster 102 and the cooling unit 101, it can realize separate liquid cooling treatment for any battery cluster 102, so as to achieve targeted cooling of any battery cluster 102.

[0044] Based on this, a cluster-level control unit 105 is installed on the coolant output path in each cooling unit 101, that is, on the sub-liquid outlet pipe 114, and the gas relay 115 in the cluster-level control unit 105 is used to monitor whether the battery cluster 102 has thermal runaway. When the battery cluster 102 has thermal runaway, the electric valve 125 in the cluster-level control unit 105 is controlled to be closed by the system-level controller 106 to close the coolant flow path of the sub-liquid outlet pipe 114 corresponding to the battery cluster 102 having thermal runaway. In this way, even if the battery cluster 102 has thermal runaway, the cooling liquid flow path of the sub-liquid outlet pipe 114 corresponding to the battery cluster 102 having thermal runaway is closed. If the pool cluster 102 contaminates the coolant of the corresponding cooling unit 101, the cluster-level control unit 105 can also be used to prevent the contaminated coolant from flowing to other cooling units 101 based on the sub-liquid outlet pipe 114. In other words, the cluster-level control unit 105 can be used to isolate the coolant in a single cooling unit 101, that is, to achieve single-cluster isolation of the coolant, and to prevent the thermal runaway phenomenon from spreading to the entire immersion liquid-cooled energy storage system 100 through the circulation of the coolant, which is beneficial to further improve the safety of the immersion liquid-cooled energy storage system 100.

[0045] In addition, after the isolation of a single cluster of coolant is achieved, it is also convenient for operators to perform maintenance on the cooling unit 101 where the coolant is contaminated separately. Since the shutoff of the electric valve 125 will not affect other cooling units 101, it is convenient to achieve single cluster maintenance of the coolant. It is worth emphasizing that in the immersion liquid-cooled energy storage system 100, in order to achieve liquid cooling treatment of multiple battery clusters 102, when the immersion liquid-cooled energy storage system 100 is operating normally, multiple cooling units 101 are filled with coolant, so the amount of coolant required for the entire immersion liquid-cooled energy storage system 100 is very large. The comprehensive design of the system-level controller 106 and the cluster-level control unit 105 provided in one embodiment of the present disclosure is conducive to reducing the amount of coolant that needs to be replaced while achieving single cluster isolation and single cluster maintenance of the coolant, thereby helping to reduce the maintenance cost of the immersion liquid-cooled energy storage system 100.

[0046] An embodiment of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0047] In some embodiments, the gas relay 115 can send out a warning signal in addition to a thermal runaway signal. Based on this, the system-level controller 106 can receive and control the electric valve 125 corresponding to the target battery cluster to shut down based on the thermal runaway signal, and can also receive and send out a warning based on the warning signal to remind the operator that there are hidden dangers in the immersion liquid-cooled energy storage system.

[0048] In some embodiments, reference Figure 3 , Figure 3A functional block diagram of a gas relay and a system-level controller in an immersion liquid-cooled energy storage system provided in an embodiment of the present disclosure, wherein the gas relay 115 may include an early warning relay 115a and an emergency stop relay 115b; the early warning relay 115a is configured such that if the accumulated amount of gas in the gas relay 115 reaches a first threshold, the early warning switch in the early warning relay 115a is closed to send an early warning signal to the system-level controller 106; the emergency stop relay 115b is configured such that if the accumulated amount of gas in the gas relay 115 reaches a second threshold, the emergency stop switch in the emergency stop relay 115b is closed to send a thermal runaway signal to the system-level controller 106; wherein the first threshold is less than the second threshold.

[0049] It is worth noting that the gas relay 115 can include two working modes, and the two working modes are triggered by different functional components. Specifically, one working mode is an early warning mode, which is triggered by the early warning relay 115a; and the other working mode is an emergency stop mode, which is triggered by the emergency stop relay 115b.

[0050] In some cases, the early warning mode can be regarded as a minor fault in the submerged liquid-cooled energy storage system 100, which causes gas to begin to gather in the gas relay 115. When the accumulated amount of gas in the gas relay 115 reaches a first threshold, the early warning switch in the early warning relay 115a is triggered to close, so as to send an early warning signal to the system-level controller 106. Among them, the minor fault in the submerged liquid-cooled energy storage system 100 may include at least the following situations: the gas production of the battery cells in the battery cluster 102 increases but thermal runaway does not occur; or, there is gas accumulation in a part of the battery cluster 102; or, there is a minor leak in the coolant pipeline connecting multiple cooling units 101, such as the sub-liquid inlet pipe 113 or the sub-liquid outlet pipe 114.

[0051] In some cases, the emergency stop mode can be regarded as a thermal runaway phenomenon of the immersion liquid-cooled energy storage system 100, which causes a large amount of gas to quickly gather in the gas relay 115. When the accumulated amount of gas in the gas relay 115 reaches the second threshold, the emergency stop switch in the emergency stop relay 115b is triggered to close, so as to send a thermal runaway signal to the system-level controller 106. In particular, when the battery cell in the battery cluster 102 is in thermal runaway, the battery cell will open the valve to release a large amount of gas, and the gas relay 115 corresponding to the battery cluster 102, that is, the target battery cluster, will monitor the large amount of gas released by the opening of the valve of the battery cell, thereby sending a thermal runaway signal to the system-level controller 106. Further, the system-level controller 106 controls the electric valve 125 corresponding to the target battery cluster to be closed based on the thermal runaway signal, so as to shut off the coolant flow path of the sub-liquid outlet pipe 114 corresponding to the battery cluster 102 that has thermal runaway, and isolate the coolant that may be contaminated in the cooling unit 101 corresponding to the target battery cluster in time.

[0052] In some examples, the first threshold value is 100ml-300ml. For example, the first threshold value may be 110ml, 120ml, 130ml, 140ml, 150ml, 160ml, 170ml, 180ml, 190ml, 200ml, 210ml, 220ml, 230ml, 240ml, 250ml, 260ml, 270ml, 280ml or 290ml. It is worth noting that the first threshold value within this range is conducive to enabling the gas relay 115 to sensitively capture the situation where there is gas intrusion in the gas relay 115, so as to improve the gas relay 1 15. The sensitivity of the early warning mode; the second threshold value is 400ml~600ml. For example, the second threshold value can be 410ml, 420ml, 430ml, 440ml, 450ml, 460ml, 470ml, 480ml, 490ml, 500ml, 510ml, 520ml, 530ml, 540ml, 550ml, 560ml, 570ml, 580ml or 590ml. It is worth noting that the second threshold value is within this range, which is conducive to prompting the gas relay 115 to enter the emergency stop mode in time, so as to facilitate the subsequent rapid isolation of the single cluster of contaminated coolant.

[0053] In some embodiments, reference Figure 4 , Figure 4 A schematic diagram of a partial cross-sectional structure of a gas relay included in an immersion liquid-cooled energy storage system provided for an embodiment of the present disclosure, wherein the gas relay 115 has an inner cavity 135 for containing coolant, and a float 145 and a baffle 155 are provided in the inner cavity 135, and the float 145 floats with the change of the liquid level of the coolant contained in the inner cavity 135, and the gas relay 115 is also provided with a magnet, a signal contact and a trip contact; the gas relay 115 can be configured such that if the float 145 is lowered to a first preset position, the magnet controls the signal contact to be connected to send a warning signal to the system-level controller 106, and if the baffle 155 is impacted to a second preset position, the magnet controls the trip contact to be connected to send a thermal runaway signal to the system-level controller 106; with the bottom surface of the inner cavity 135 as the reference plane, the second preset position is lower than the first preset position.

[0054] It is worth noting that when the immersion liquid-cooled energy storage system 100 is operating normally, the gas relay 115 is filled with coolant. When a minor fault or thermal runaway occurs in the immersion liquid-cooled energy storage system 100, gas will gather in the gas relay 115, causing the coolant level in the gas relay 115 to drop, and the float 145 drops with the drop in the coolant level, so that when the float 145 drops to the first preset position, the magnet control signal contact is connected to send a warning signal to the system-level controller 106. It is worth noting that when the immersion liquid-cooled energy storage system 100 experiences thermal runaway, the gas will quickly gather in the gas relay 115, which may cause the coolant level in the gas relay 115 to quickly drop to the bottom. The rapid change in the gas pressure in the gas relay 115 and the rapid drop of the float 145 will both cause a greater impact on the baffle 155 in the gas relay 115, causing the baffle 155 to be impacted to the second preset position, and the magnet-controlled tripping contact is connected to send a thermal runaway signal to the system-level controller 106.

[0055] In some cases, if the float 145 is lowered to the first preset position, the accumulated gas in the gas relay 115 reaches the first threshold; if the baffle 155 is impacted to the second preset position, the accumulated gas in the gas relay 115 reaches the second threshold.

[0056] In some embodiments, the gas relay 115 may be a single-float gas relay or a double-float gas relay.

[0057] In some embodiments, reference Figure 5 , Figure 5 A functional block diagram of a system-level controller, a circuit breaker, and a battery cluster in an immersion liquid-cooled energy storage system provided in an embodiment of the present disclosure. The immersion liquid-cooled energy storage system 100 may also include at least two circuit breakers 107, the circuit breakers 107 are electrically connected to the battery clusters 102, and the circuit breakers 107 correspond to the battery clusters 102 one-to-one; the system-level controller 106 is configured to receive and control the circuit breaker 107 corresponding to the target battery cluster to shut down based on the thermal runaway signal to cut off the power supply of the target battery cluster.

[0058] It is worth noting that the system-level controller 106 not only relies on the linkage between the gas relay 115 and the electric valve 125 in the cluster-level control unit 105, so that when the gas relay 115 detects that the battery cluster 102 has thermal runaway, the electric valve 125 is controlled to close the electric valve 125 corresponding to the target battery cluster to achieve single-cluster isolation of the coolant, but also the system-level controller 106 can control the circuit breaker 107 corresponding to the target battery cluster to shut down based on the received thermal runaway signal, so that the target battery cluster with thermal runaway stops running, so as to avoid further deterioration of the thermal runaway phenomenon caused by the current in the target battery cluster, and timely curb the thermal runaway phenomenon in the target battery cluster, thereby further improving the safety of the immersion liquid-cooled energy storage system 100.

[0059] In some embodiments, reference Figure 6 , Figure 6 This is a schematic diagram of a second partial cross-sectional structure of an immersion liquid-cooled energy storage system provided in an embodiment of the present disclosure. The cooling unit 101 may have an upper side 101a and a lower side 101b that are opposite to each other along the height direction of the immersion liquid-cooled energy storage system 100; in the sub-liquid outlet pipe 114 and the sub-liquid inlet pipe 113 connected to the same cooling unit 101, the sub-liquid outlet pipe 114 is connected to the upper side 101a, and the sub-liquid inlet pipe 113 is connected to the lower side 101b.

[0060] It is worth noting that the cluster-level control unit 105 is installed on the sub-liquid outlet pipe 114, and the sub-liquid outlet pipe 114 is connected to the upper side 101a, which is conducive to ensuring that the gas relay 115 in the cluster-level control unit 105 is installed on the top of the cooling unit 101. In this way, when gas is generated due to a fault in the immersion liquid-cooled energy storage system 100, the gas gradually gathers upward and is preferentially detected by the gas relay 115 located at the top, thereby improving the sensitivity of the gas relay 115 in detecting gas, so that the gas relay 115 can send out a warning signal or a thermal runaway signal in time, and the system-level controller 106 (reference Figure 5 ) can timely perform corresponding control actions based on the received warning signal or thermal runaway signal. Compared with the current method of using the float ball set in the cooling unit 101 to float significantly only when the gas accumulates to a certain amount to generate a corresponding alarm signal, the design of the positional relationship between the cooling unit 101 and the sub-liquid outlet pipe 114 and the sub-liquid inlet pipe 113 in one embodiment of the present disclosure, as well as the design of installing the cluster-level control unit 105 on the sub-liquid outlet pipe 114, is conducive to faster detection of faults in the immersion liquid-cooled energy storage system 100 and reducing the hysteresis of detection.

[0061] In some embodiments, continue to refer to Figure 6The sub-liquid outlet pipe 114 has a first end 114a close to the cooling unit 101 and a second end 114b away from the cooling unit 101, and the cluster-level control unit 105 is installed on the second end 114b; taking the plane where the lower side 101b is located as the reference plane, the second distance between the second end 114b and the reference plane is greater than the first distance between the first end 114a and the reference plane.

[0062] In some cases, the reference plane can be regarded as a horizontal plane, the sub-liquid outlet pipe 114 is inclined relative to the reference plane, and the cluster-level control unit 105 is installed at an upwardly tilted end of the sub-liquid outlet pipe 114, namely, the second end 114b.

[0063] It is worth noting that the gas gathered in the gas relay 115 of the cluster-level control unit 105 can finally rise to the gas relay 115 from the corresponding battery cluster via the cooling unit 101 and the sub-liquid outlet pipe 114. Based on the characteristics of gas gathering upward, the sub-liquid outlet pipe 114 is designed to be inclined, so that the bubbles in the coolant are gathered upward, which is conducive to increasing the gathering speed of the bubbles in the coolant. Moreover, the gas relay 115 is arranged at the tilted end of the sub-liquid outlet pipe 114, which is conducive to further improving the sensitivity of the gas relay 115 to detect gas, so as to ensure that the gas relay 115 can detect the failure of the immersion liquid-cooled energy storage system 100 in time.

[0064] In some embodiments, continue to refer to Figure 6 , the angle β between the line between the first end 114a and the second end 114b and the reference plane is 1.5° to 6°. In other words, the inclination angle of the sub-liquid outlet pipe 114 relative to the reference plane is 1.5° to 6°.

[0065] If the angle β between the line connecting the first end 114a and the second end 114b and the reference plane is less than 1.5°, the inclination of the sub-liquid outlet pipe 114 is smaller than that of the reference plane, and when the sub-liquid outlet pipe 114 itself has a certain length, the effect of pushing the bubbles in the coolant to gather upward is limited; if the angle β between the line connecting the first end 114a and the second end 114b and the reference plane is greater than 6°, the inclination of the sub-liquid outlet pipe 114 is greater than that of the reference plane, and the sub-liquid outlet pipe 114 as a whole occupies a larger space in the vertical direction in the immersion liquid-cooled energy storage system 100, which not only makes the sub-liquid outlet pipe 114 easy to be accidentally touched and broken, but also is not conducive to improving the overall integration density of the immersion liquid-cooled energy storage system 100. Therefore, the angle β between the line connecting the first end 114a and the second end 114b and the reference plane is designed to be 1.5°~6°, which is beneficial to improving the effect of pushing the bubbles in the coolant to gather upward while avoiding that the sub-liquid outlet pipe 114 as a whole occupies too much space in the vertical direction in the immersion liquid-cooled energy storage system 100, so as to ensure the overall high integration density of the immersion liquid-cooled energy storage system 100.

[0066] In some examples, the angle between the line between the first end 114a and the second end 114b and the reference plane can be 1.6°, 1.8°, 2°, 2.4°, 2.5°, 2.8°, 3°, 3.2°, 3.5°, 3.6°, 4°, 4.3°, 4.5°, 4.7°, 5°, 5.4°, 5.5° or 5.8°, etc.

[0067] In some embodiments, continue to refer to Figure 6 The immersed liquid-cooled energy storage system 100 may further include: a float 108, which is located on the liquid surface of the coolant contained in the cooling unit 101, and the float 108 floats with the change of the liquid level of the coolant contained in the cooling unit 101; a float switch is provided in the cooling unit 101; the float switch is configured so that if the float 108 is lowered to a third preset position, the float switch is closed; the system-level controller 106 is also configured to receive and control the electric valve 125 corresponding to the target battery cluster to be closed based on the thermal runaway signal if the float switch is closed.

[0068] When the immersion liquid-cooled energy storage system 100 operates normally, the cooling unit 101 is also filled with coolant. When the immersion liquid-cooled energy storage system 100 has thermal runaway, the battery cells in the battery cluster 102 will open the valve to release a large amount of gas. At this time, not only will the gas quickly gather in the gas relay 115, but the liquid level of the coolant contained in the cooling unit 101 will also drop significantly, causing the float 108 to drop with the drop in the liquid level of the coolant contained in the cooling unit 101, until the float 108 drops to the third preset position, and the float switch is closed, so that the system-level controller 106 can receive and control the electric valve 125 corresponding to the target battery cluster to shut down based on the thermal runaway signal.

[0069] It is worth noting that the volume of coolant contained in a single cooling unit 101 is much larger than the volume of coolant contained in a single gas relay 115. When a coolant pipeline connecting multiple cooling units 101, such as the sub-inlet pipe 113 or the sub-outlet pipe 114, has a serious leak, a large amount of gas may gather in the gas relay 115, causing the coolant level to drop to the bottom. At this time, the coolant level contained in the cooling unit 101 may not fluctuate much. Based on this, the system-level controller 106 is designed to receive and control the electric valve 125 corresponding to the target battery cluster to be shut down based on the thermal runaway signal when the float switch is closed. In other words, when the gas relay 115 sends a thermal runaway signal and the float switch is closed at the same time, the system-level controller 106 will control the electric valve 125 corresponding to the target battery cluster to be shut down based on the thermal runaway signal. This allows the operator to clearly distinguish between the following two situations based on whether the gas relay 115 sends a thermal runaway signal and whether the electric valve 125 is shut down: a serious leak occurs in the coolant pipeline connecting multiple cooling units 101, or thermal runaway occurs in the battery cluster 102.

[0070] Specifically, if the gas relay 115 sends a thermal runaway signal, but the system-level controller 106 does not control the electric valve 125 to shut down, it can be preliminarily determined that a serious leak occurs in the coolant pipeline connecting the multiple cooling units 101, but the battery cluster 102 does not experience thermal runaway, which facilitates the operator to promptly inspect and repair the coolant pipeline connecting the multiple cooling units 101; if the gas relay 115 sends a thermal runaway signal, and the system-level controller 106 controls the electric valve 125 to shut down, it can be preliminarily determined that the battery cluster 102 has thermal runaway, which facilitates the operator to promptly lock the battery cluster 102 that has experienced thermal runaway.

[0071] In some embodiments, reference Figure 7 or Figure 8The energy storage system may further include: a main liquid inlet pipe 103 connected to a plurality of sub-liquid inlet pipes 113, and a main liquid outlet pipe 104 connected to a plurality of sub-liquid outlet pipes 114. It is worth noting that the coolant flows from the box storing the coolant to the plurality of cooling units 101 via the main liquid inlet pipe 103, and then flows from the plurality of cooling units 101 to the main liquid outlet pipe 104 via the sub-liquid outlet pipe 114, and finally flows from the main liquid outlet pipe 104 back into the box storing the coolant, so as to realize the circulation of the coolant in the immersion liquid-cooled energy storage system 100.

[0072] It should be noted that Figure 7 A schematic diagram of a third partial cross-sectional structure of an immersion liquid-cooled energy storage system provided in one embodiment of the present disclosure; Figure 8 A schematic diagram of a fourth partial cross-sectional structure of an immersion liquid-cooled energy storage system provided in one embodiment of the present disclosure.

[0073] In some cases, continue to refer to Figure 7 or Figure 8 The box for storing the coolant may include: a liquid cooler 109 and a plate heat exchange component 119 , which cooperate to cool the coolant flowing in from the main liquid outlet pipe 104 and provide it to the main liquid inlet pipe 103 again.

[0074] In some cases, continue to refer to Figure 7 or Figure 8 The energy storage system may further include: a circulation pump 129 , which is arranged on the main liquid inlet pipe 103 , and is used to further ensure the circulation of the coolant in the immersion liquid-cooled energy storage system 100 .

[0075] In some cases, continue to refer to Figure 7 or Figure 8 The energy storage system may further include: a plurality of check valves 139, each sub-liquid inlet pipe 113 is provided with at least one check valve 139 on one side close to the cooling unit 101, for controlling the flow rate of the coolant in the sub-liquid inlet pipe 113, and each sub-liquid outlet pipe 114 is also provided with at least one check valve 139 on one side close to the cooling unit 101, for controlling the flow rate of the coolant in the sub-liquid outlet pipe 114.

[0076] In some embodiments, the energy storage system may further include: a vent (not shown), which is disposed on the top surface of the gas relay 115 along the height direction of the immersion liquid-cooled energy storage system 100. In this way, when a minor fault occurs in the immersion liquid-cooled energy storage system 100, for example, the gas production of the battery cells in the battery cluster 102 increases but no thermal runaway occurs, there is gas accumulation in a part of the battery cluster 102, or there is a minor leak in the coolant pipeline connecting multiple cooling units 101, when the operator performs maintenance, the gas gathered in the gas relay 115 can be discharged in time by means of the vent disposed on the top surface of the gas relay 115, and the gas relay 115 can be filled with coolant again in time, so that the immersion liquid-cooled energy storage system 100 can resume normal operation.

[0077] In summary, the cluster-level control unit 105 is installed on the coolant output path in each cooling unit 101, that is, on the sub-liquid outlet pipe 114, and the gas relay 115 in the cluster-level control unit 105 is used to monitor whether the battery cluster 102 has thermal runaway. When the battery cluster 102 has thermal runaway, the electric valve 125 in the cluster-level control unit 105 is controlled to be closed by the system-level controller 106 to close the coolant flow path of the sub-liquid outlet pipe 114 corresponding to the battery cluster 102 having thermal runaway. In this way, even if thermal runaway occurs, If the battery cluster 102 contaminates the coolant of the corresponding cooling unit 101, the cluster-level control unit 105 can also be used to prevent the contaminated coolant from flowing to other cooling units 101 based on the sub-liquid outlet pipe 114. In other words, the cluster-level control unit 105 can be used to isolate the coolant in a single cooling unit 101, that is, to achieve single-cluster isolation of the coolant, and can also prevent the thermal runaway phenomenon from spreading to the entire immersion liquid-cooled energy storage system 100 through the circulation of the coolant, which is beneficial to further improve the safety of the immersion liquid-cooled energy storage system 100.

[0078] Another embodiment of the present disclosure also provides a cluster-level control circuit, which is applied to the immersion liquid-cooled energy storage system provided in the above embodiment. The cluster-level control circuit provided in another embodiment of the present disclosure will be described in detail below in conjunction with the accompanying drawings. It should be noted that the parts that are the same or corresponding to the above embodiment will not be repeated here.

[0079] Combined with reference Figure 8 and Fig. 9 , Fig. 9A cluster-level control circuit for an immersion liquid-cooled energy storage system provided in another embodiment of the present disclosure includes: a power supply; an emergency stop switch KA4 and a first control switch SCU:DI2 connected in parallel with the power supply, and the emergency stop switch KA4 and the first control switch SCU:DI2 are connected in series; the emergency stop switch KA4 is configured so that if thermal runaway occurs in the battery cluster 102, the gas relay 115 controls the emergency stop switch KA4 to close; the first control switch SCU:DI2 is configured so that if thermal runaway occurs in the battery cluster 102, the system-level controller 106 controls the first control switch SCU:DI2 to close; an electric valve 125 connected to the first control switch SCU:DI2, and the electric valve 125 is configured so that if the electric valve 125 is electrically connected to the power supply, it is turned off.

[0080] It should be noted that, in conjunction with the reference Figure 3 , Figure 4 , Figure 8 and Fig. 9 , the closing or shutting off of the emergency stop switch KA4 is controlled by the emergency stop relay 115b. If the accumulated gas in the gas relay 115 reaches the second threshold value or the baffle 155 is impacted to the second preset position, that is, when the battery cluster 102 has thermal runaway, the emergency stop relay 115b will be triggered to control the emergency stop switch KA4 to be turned on, and a thermal runaway signal will be sent to the system-level controller 106; the closing or shutting off of the first control switch SCU: DI2 is controlled by the system-level controller 106. If the system-level controller 106 receives a thermal runaway signal, the first control switch SCU: DI2 will be triggered to close. It is worth noting that only when the emergency stop switch KA4 and the first control switch SCU: DI2 are both closed, the electric valve 125 is electrically connected to the power supply, so that the electric valve 125 is turned off to cut off the coolant flow path of the sub-liquid outlet pipe 114 corresponding to the battery cluster 102 that has thermal runaway.

[0081] also, Fig. 9 A cluster-level control circuit schematic diagram applied to an immersion liquid-cooled energy storage system provided as another embodiment of the present disclosure can also be regarded as a cluster-level control electrical schematic diagram, circuit schematic diagram or circuit diagram applied to the immersion liquid-cooled energy storage system, which is used to clarify the circuit connection relationship between components such as the gas relay 115, the system-level controller 106 and the power supply in the immersion liquid-cooled energy storage system, as well as the circuit control logic, so as to at least achieve single-cluster isolation of contaminated coolant.

[0082] In some examples, the voltage of the power supply may be 24V.

[0083] In some embodiments, continue to combine reference Figure 8 and Fig. 9The cluster-level control circuit may further include: an early warning switch KA3 and a second control switch SCU: DI1 connected in parallel with the power supply, and the early warning switch KA3 and the second control switch SCU: DI1 are connected in series; the early warning switch KA3 is configured so that if a slight fault occurs in the battery cluster 102 or a slight leakage occurs in the coolant, the gas relay 115 controls the early warning switch KA3 to close; the second control switch SCU: DI1 is configured so that if a slight fault occurs in the battery cluster 102 or a slight leakage occurs in the coolant, the system-level controller 106 controls the second control switch SCU: DI1 to close.

[0084] It should be noted that the closing or shutting down of the early warning switch KA3 is controlled by the early warning relay 115a. If the accumulated gas in the gas relay 115 reaches the first threshold value or the float 145 is lowered to the first preset position, that is, a minor fault occurs in the battery cluster 102 or a minor leakage of the coolant occurs, the early warning relay 115a will be triggered to control the early warning switch KA3 to be turned on, and a warning signal will be sent to the system-level controller 106; the closing or shutting down of the second control switch SCU: DI1 is controlled by the system-level controller 106. If the system-level controller 106 receives the early warning signal, the second control switch SCU: DI1 will be triggered to close.

[0085] In some cases, the cluster-level control circuit may further include: a float switch KA1 and a float switch KA2. When the immersion liquid-cooled energy storage system 100 operates normally, the float switch KA1 and the float switch KA2 are both in an open state. If the float 145 is lowered to the first preset position, the magnet controls the signal contact to be connected, that is, the float switch KA1 is controlled to be closed, thereby further triggering the warning relay 115a to send a warning signal to the system-level controller 106. Fig. 9 The float switch KA1 and the warning relay 115a are connected in series to reflect the interaction between the float switch KA1 and the warning relay 115a sending the warning signal; if the float 108 in the cooling unit 101 is lowered to the third preset position, the float switch KA2 is controlled to close, thereby further triggering the emergency stop relay 115b to send a thermal runaway signal to the system-level controller 106, Fig. 9 The float switch KA2 and the emergency stop relay 115b are connected in series to reflect the interaction between the float switch KA2 and the thermal runaway signal emitted by the emergency stop relay 115b.

[0086] In some embodiments, reference Fig. 9 The cluster-level control circuit may further include: a circuit breaker 107 connected in parallel with the first control switch SCU:DI2, the circuit breaker 107 being configured to be turned off if the circuit breaker 107 is electrically connected to the power supply.

[0087] It is worth noting that the electric valve 125 is electrically connected to the power supply only when the emergency stop switch KA4 and the first control switch SCU:DI2 are both closed. Based on this, the circuit breaker 107 is electrically connected to the power supply only when the emergency stop switch KA4 and the first control switch SCU:DI2 are both closed. At this time, the circuit breaker 107 is powered on and off, so that the target battery cluster with thermal runaway stops running, so as to avoid further deterioration of the thermal runaway phenomenon caused by the current in the target battery cluster, and timely curb the thermal runaway phenomenon in the target battery cluster, thereby further improving the safety of the immersion liquid-cooled energy storage system 100.

[0088] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for implementing the present disclosure, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of the embodiments of the present disclosure. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of the present disclosure, so the protection scope of the embodiments of the present disclosure shall be based on the scope defined in the claims.

Claims

1. An immersion liquid-cooled energy storage system, characterized in that: include: at least two cooling units, each of which corresponds to a battery cluster one by one, and each cooling unit has a receiving cavity for receiving the battery cluster; At least two sub-liquid inlet pipes and sub-liquid outlet pipes corresponding to the sub-liquid inlet pipes one by one, wherein one sub-liquid outlet pipe and one sub-liquid inlet pipe are respectively connected to the same cooling unit; A cluster-level control unit is installed on the sub-liquid outlet pipe and corresponds to the sub-liquid outlet pipe one by one, and the cluster-level control unit includes a gas relay and an electric valve; The gas relay is configured to send a thermal runaway signal to the system-level controller if the battery cluster has thermal runaway; the electric valve is configured to open or close the coolant flow path of the sub-liquid outlet pipe corresponding to the electric valve; The system-level controller is electrically connected to the cluster-level control unit; The battery cluster that sends out the thermal runaway signal is used as a target battery cluster, and the system-level controller is configured to at least receive and control the electric valve corresponding to the target battery cluster to be closed based on the thermal runaway signal; The gas relay includes an early warning relay and an emergency stop relay, and the gas relay includes an early warning mode triggered by the early warning relay and an emergency stop mode triggered by the emergency stop relay; wherein, in the early warning mode, it is determined that a minor fault occurs in the immersion liquid-cooled energy storage system, and the situation where a minor fault occurs in the immersion liquid-cooled energy storage system includes a minor leak in a coolant pipeline connecting a plurality of the cooling units; The warning relay is configured such that, if the accumulated amount of gas in the gas relay reaches a first threshold, the warning switch in the warning relay is closed to send a warning signal to the system-level controller; The emergency stop relay is configured such that, if the accumulated amount of gas in the gas relay reaches a second threshold, the emergency stop switch in the emergency stop relay is closed to send a thermal runaway signal to the system-level controller; wherein the first threshold is less than the second threshold; The submerged liquid-cooled energy storage system further includes: a float located on the liquid surface of the coolant contained in the cooling unit, and the float floats as the liquid level of the coolant contained in the cooling unit changes; a float switch is provided in the cooling unit; The float switch is configured such that if the float is lowered to a third preset position, the float switch is closed; The system-level controller is also configured such that, if the gas relay sends out the thermal runaway signal and the float switch is closed, the system-level controller receives and controls the electric valve corresponding to the target battery cluster to close based on the thermal runaway signal; if the gas relay sends out the thermal runaway signal and the float switch is not closed, the system-level controller does not control the electric valve to close.

2. The immersion liquid-cooled energy storage system according to claim 1, characterized in that: The gas relay has an inner cavity containing coolant, a float and a baffle are arranged in the inner cavity, the float floats with the change of the liquid level of the coolant contained in the inner cavity, and the gas relay is also provided with a magnet, a signal contact and a trip contact; The gas relay is configured such that if the float is lowered to a first preset position, the magnet controls the signal contact to be connected so as to send a warning signal to the system-level controller, and if the baffle is impacted to a second preset position, the magnet controls the trip contact to be connected so as to send a thermal runaway signal to the system-level controller; Taking the bottom surface of the inner cavity as a reference plane, the second preset position is lower than the first preset position.

3. The immersion liquid-cooled energy storage system according to claim 1 or 2, characterized in that: Also included are at least two circuit breakers, the circuit breakers are electrically connected to the battery clusters, and the circuit breakers correspond to the battery clusters one by one; The system-level controller is configured to receive and control the circuit breaker corresponding to the target battery cluster to be turned off based on the thermal runaway signal, so as to cut off power supply of the target battery cluster.

4. The immersion liquid-cooled energy storage system according to claim 1 or 2, characterized in that: The cooling unit has an upper side and a lower side relative to each other in the height direction of the immersion liquid-cooled energy storage system; among the sub-liquid outlet pipe and the sub-liquid inlet pipe connected to the same cooling unit, the sub-liquid outlet pipe is connected to the upper side, and the sub-liquid inlet pipe is connected to the lower side.

5. The immersion liquid-cooled energy storage system according to claim 4, characterized in that: The sub-liquid outlet pipe has a first end close to the cooling unit and a second end away from the cooling unit, and the cluster-level control unit is installed on the second end; taking the plane where the lower side is located as a reference plane, a second distance between the second end and the reference plane is greater than a first distance between the first end and the reference plane.

6. The immersion liquid-cooled energy storage system according to claim 5, characterized in that: An angle between a line between the first end and the second end and the reference plane is 1.5° to 6°.

7. A cluster-level control circuit, applied to an immersion liquid-cooled energy storage system according to any one of claims 1 to 6, characterized in that: include: power supply; An emergency stop switch and a first control switch connected in parallel with the power supply, the emergency stop switch and the first control switch being connected in series; the emergency stop switch being configured such that if thermal runaway occurs in the battery cluster, the gas relay controls the emergency stop switch to close; the first control switch being configured such that if thermal runaway occurs in the battery cluster, the system-level controller controls the first control switch to close; The electric valve associated with the first control switch is configured to be closed if the electric valve is electrically connected to the power supply.

8. The cluster level control circuit according to claim 7, characterized in that: Also includes: An early warning switch and a second control switch connected in parallel with the power supply, the early warning switch and the second control switch being connected in series; The early warning switch is configured such that if a minor fault occurs in the battery cluster or a minor leak occurs in the coolant, the gas relay controls the early warning switch to close; the second control switch is configured such that if a minor fault occurs in the battery cluster or a minor leak occurs in the coolant, the system-level controller controls the second control switch to close; and / or, A circuit breaker is connected in parallel with the first control switch, and the circuit breaker is configured to be turned off if the circuit breaker is electrically connected to the power source.

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