Battery system and thermal management method

Abstract

The invention discloses a battery system and a heat management method, and relates to the technical field of energy storage, the battery system comprises an immersion box and a plurality of battery packs, and also comprises a controller, a temperature measurement assembly, a control valve group, a spray pipe, a heat management module and a fire protection module; cooling liquid is contained in the immersion box, an opening is formed in the top of the immersion box, and the multiple battery packs are contained in the immersion box and soaked in the cooling liquid. The battery pack comprises a shell and a plurality of batteries, a cavity is formed in the shell, and cooling liquid is contained in the cavity; an opening is formed in the top of the shell; the plurality of batteries are accommodated in the cavity and are soaked in the cooling liquid; the spraying pipes are arranged in the cavities of the battery packs in a one-to-one correspondence manner; the heat management module and the fire-fighting module selectively communicate with the spraying pipelines in the battery packs through the control valve group; the temperature measuring assembly is used for measuring the temperature of the batteries in the battery pack, and the controller is used for controlling the valve group to be switched on or switched off according to the temperature of the batteries. The battery pack is designed in a non-sealing mode, and the unreliable condition of a system under high pressure is avoided.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and more specifically to a battery system and thermal management method. Background Technology

[0002] Currently, lithium batteries are rapidly developing towards higher power, higher specific energy, and longer lifespan. Cooling methods for energy storage batteries are mainly of two types: cold plate type and immersion type. Liquid cooling primarily uses indirect cooling systems, employing a sealed coolant circulation structure, consisting of a liquid cooling plate, circulation pump set, control system, and piping. Immersion systems use insulating liquid in direct contact with the battery for cooling, offering superior temperature uniformity and heat dissipation.

[0003] Existing submerged battery systems include a housing with multiple battery packs arranged vertically within it, each layer sealed with a cover. While this sealed structure helps isolate individual battery packs, in extreme cases, such as thermal runaway within a pack, the sealed housing can cause a rapid increase in internal pressure. If the pressure cannot be effectively released, the battery pack may rupture, allowing thermal runaway to spread to other batteries and trigger a larger fire. During charging and discharging, batteries may produce flammable gases. Without proper venting, these gases can accumulate in the sealed battery housing, and upon reaching a certain concentration, they can easily ignite and explode, increasing the fire hazard. Summary of the Invention

[0004] This invention aims to address, to a certain extent, one of the technical problems in related technologies. To this end, this invention provides a battery system and a thermal management method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a battery system, including an immersion tank and multiple battery packs, and further including a controller, a temperature measuring component, a control valve group, a sprinkler pipe, a thermal management module and a fire protection module;

[0006] The immersion tank is filled with coolant, and the top of the immersion tank is open. Multiple batteries are contained inside the immersion tank and immersed in the coolant.

[0007] The battery pack includes a housing and a plurality of batteries. The housing has an interior cavity containing coolant. The top of the housing has an opening, and the plurality of batteries are housed in the cavity and immersed in the coolant.

[0008] The sprinkler pipes are installed one-to-one in the cavities of each battery pack. The thermal management module and the fire protection module are selectively connected to the sprinkler pipes in each battery pack through the control valve group. The temperature measuring component is used to measure the temperature of the batteries in each battery pack, and the controller is used to control the control valve group to open or close according to the temperature of the batteries.

[0009] Optionally, the thermal management module includes a thermal management inlet pipeline, a thermal management return pipeline, a thermal management heat exchanger, a thermal management liquid storage tank, a thermal management drive pump, and a refrigeration unit;

[0010] The outlet of the thermal management liquid inlet pipe is connected to the spray pipe in each of the battery packs. The outlet of the thermal management liquid return pipe is sequentially connected to the thermal management drive pump, the thermal management liquid storage tank, the secondary side of the thermal management heat exchanger, and the inlet of the thermal management liquid inlet pipe. The primary side of the thermal management heat exchanger is connected to the refrigeration unit. The battery pack is also provided with a liquid return pipe, and the thermal management liquid return pipe is connected to the outlet of the liquid return pipe in each of the battery packs.

[0011] Optionally, the fire protection module includes a fire-fighting storage tank, a fire-fighting heat exchanger, a fire-fighting drive pump, and a pumping pump; the inlet of the fire-fighting return pipeline is connected to the outlet of the return pipeline in each of the battery packs, and the outlet of the fire-fighting return pipeline is sequentially connected to the fire-fighting drive pump, the fire-fighting storage tank, the secondary side of the fire-fighting heat exchanger, and the inlet of the fire-fighting return pipeline; the primary side of the fire-fighting heat exchanger is connected to the refrigeration unit; the bottom of the immersion tank is provided with a liquid outlet, and the liquid outlet of the immersion tank is sequentially connected to the pumping pump and the heat management storage tank.

[0012] Optionally, the thermal management liquid inlet pipeline includes a thermal management liquid inlet main pipe, thermal management liquid inlet branch pipes and thermal management liquid inlet control valve. The thermal management liquid inlet branch pipes are connected to the spray pipes in each of the battery packs in a one-to-one correspondence, and each thermal management branch pipe is connected to the thermal management main pipe.

[0013] The fire-fighting liquid inlet pipeline includes a main fire-fighting liquid inlet pipe and multiple branch fire-fighting liquid inlet pipes. Each branch fire-fighting liquid inlet pipe is connected to a corresponding sprinkler pipe in each of the battery packs, and each branch fire-fighting liquid inlet pipe is connected to the main fire-fighting liquid inlet pipe.

[0014] Optionally, the thermal management return pipeline includes a thermal management return main pipe, thermal management return branch pipes and thermal management return control valves. The thermal management return branch pipes are connected to the spray pipelines in each of the battery packs in a one-to-one correspondence, and each thermal management branch pipe is connected to the thermal management main pipe.

[0015] The fire return pipeline includes a main fire return pipe and multiple branch fire return pipes. Each branch fire return pipe is connected to a corresponding sprinkler pipe in each of the battery packs, and each branch fire pipe is connected to the main fire return pipe.

[0016] Optionally, the batteries in the battery pack are arranged in an array. The spray pipe includes a main inlet pipe and multiple spray branch pipes. The spray branch pipes are arranged one-to-one on the top of each row of batteries and extend in the direction of the row. The spray branch pipes have multiple spray holes on the side facing the battery. One end of the main inlet pipe extends out of the housing and is connected to the thermal management liquid inlet pipe and the fire protection liquid inlet pipe. The other end of the main inlet pipe is located inside the housing and is connected to each of the spray branch pipes.

[0017] Optionally, the return pipe includes a first pipe section and a second pipe section. The first pipe section extends along the row direction of the multiple arrayed batteries and is provided with multiple spaced return holes. One end of the second pipe is connected to the first pipe section, and the other end of the second pipe extends out of the housing and communicates with the thermal management return pipe and the fire protection return pipe.

[0018] Optionally, the control valve group includes a spray control valve, a thermal management inlet control valve, a fire-fighting inlet control valve, a thermal management return control valve, a fire-fighting return control valve, and a suction valve; the spray branch pipe is equipped with a spray control valve, the thermal management branch pipe is equipped with a thermal management inlet control valve, the fire-fighting branch pipe is equipped with a fire-fighting inlet control valve, the thermal management branch pipe is equipped with a thermal management return control valve, the fire-fighting branch pipe is equipped with a fire-fighting return control valve, and the outlet of the immersion tank is equipped with the suction valve;

[0019] The temperature measurement component includes multiple temperature sensors, each of which is used to measure the temperature of each battery. The controller controls the on / off state of the spray control valve, the thermal management liquid inlet control valve, the fire-fighting liquid inlet control valve, the thermal management liquid return control valve, the fire-fighting liquid return control valve, and the extraction valve based on the temperature of each battery.

[0020] Optionally, it also includes a mounting frame having multiple stacked mounting slots, in which the battery packs are correspondingly disposed; the multiple battery packs are stacked on the mounting frame to form battery clusters, and at least two battery clusters are disposed in the housing.

[0021] A second aspect of the present invention provides a thermal management method applied to a battery system as provided in the first aspect of the present invention, comprising the following steps:

[0022] The temperature of each battery is detected in real time, and the temperature change rate of each battery is obtained based on the temperature of each battery. The temperature change rate is the rate at which the temperature of the battery changes with time per unit time.

[0023] If the rate of temperature change of the battery is greater than the preset maximum rate of temperature change, the battery pack to which the battery belongs is determined according to the preset correspondence between batteries and battery packs.

[0024] After controlling all batteries in the battery pack to be powered off for a preset time, the thermal management liquid inlet control valve and thermal management liquid return control valve corresponding to the battery pack are closed, the fire-fighting liquid inlet control valve and fire-fighting liquid return control valve corresponding to the battery pack are opened, the spray control valve corresponding to the battery is opened, and the drain valve of the housing is opened.

[0025] The technical solution provided by this invention has the following beneficial effects: The battery packs are immersed in an immersion tank. Optionally, the top of the battery pack tank can be open or not sealed. A thermal management module and a fire suppression module are designed separately. The coolant in the fire suppression module and the coolant in the thermal management module are the same insulating cooling liquid, ensuring reliable system operation. The battery packs are clustered and immersed in the overall immersion tank. During normal operation, the coolant in the battery packs is circulated through the thermal management module for cooling. During thermal runaway control, the coolant in the immersion tank is discharged, isolating the coolant in each battery pack to prevent contamination, and the coolant in each battery pack is recovered. During fire suppression, the fire suppression coolant operates under harsh conditions and is easily contaminated; this prevents cross-contamination between the fire suppression coolant and the thermal management coolant, reducing maintenance costs. Abnormal batteries are located using temperature sensing components, allowing fire suppression spray to accurately target batteries in abnormal battery packs. This optimizes the traditional system's ability to only reach the battery pack level, improves the cooling effect of the fire suppression module, and reduces operational losses.

[0026] These features and advantages of the present invention will be disclosed in detail in the following specific embodiments and accompanying drawings. The preferred embodiments or means of the present invention will be shown in detail in conjunction with the accompanying drawings, but are not intended to limit the technical solutions of the present invention. In addition, each of these features, elements and components appearing in the following text and drawings is a plurality of, and different symbols or numbers are used for convenience of representation, but all represent parts with the same or similar construction or function. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings:

[0028] Figure 1 This is a schematic diagram of the internal structure of the battery system of the present invention (the mounting bracket is not shown).

[0029] Figure 2 This is a perspective view of the battery system of the present invention.

[0030] Figure 3This is a structural schematic diagram of the battery cluster, spray pipe, thermal management liquid inlet pipe, thermal management liquid return pipe, fire-fighting liquid inlet pipe, and fire-fighting liquid return pipe of the present invention from one angle.

[0031] Figure 4 This is a structural schematic diagram of the battery cluster, spray pipe, thermal management liquid inlet pipe, thermal management liquid return pipe, fire-fighting liquid inlet pipe, and fire-fighting liquid return pipe of the present invention from another angle.

[0032] Figure 5 This is a top view of the present invention.

[0033] Figure 6 This is a flowchart of the thermal management method of the present invention.

[0034] Among them, 10, thermal management liquid inlet control valve; 20, battery pack; 21, battery; 22, housing; 32, liquid inlet main pipe; 30, spray pipe; 31, spray control valve; 33, spray branch pipe; 40, thermal management liquid inlet pipeline; 401, thermal management liquid inlet control valve; 411, thermal management liquid return control valve; 50, fire-fighting liquid inlet pipeline; 501, fire-fighting liquid inlet control valve; 51, fire-fighting liquid return pipeline; 511, fire-fighting liquid return control valve; 60, liquid return pipe; 61, first pipe section; 610, liquid return hole; 62, second pipe section. Detailed Implementation

[0035] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described are intended to explain the present invention and should not be construed as limiting the invention.

[0036] The terms "an embodiment," "example," or "trademark" used in this specification refer to a particular feature, structure, or characteristic described in connection with the embodiment itself that may be included in at least one embodiment disclosed in this patent. The phrase "in an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0037] In related technologies, submerged battery systems include a housing, multiple battery packs arranged vertically within the housing, and each battery pack having a sealed cover. While the sealed structure helps isolate individual battery packs, in extreme cases, such as thermal runaway within a battery pack, the sealed battery pack may experience a rapid increase in internal pressure. If the battery pack cannot effectively release the pressure, it may rupture, allowing thermal runaway to spread to other batteries and cause a larger-scale fire. During charging and discharging, batteries may produce flammable gases, which may accumulate inside the sealed battery housing. Once these gases reach a certain concentration, they can easily explode upon contact with an ignition source, increasing fire hazards. Secondly, because the submerged battery system uses the same circulation system for both thermal management and fire suppression, during fire suppression, the electrolyte and active materials ejected from thermally runaway cells can spread throughout the piping system with the coolant, contaminating other battery packs that have not experienced thermal runaway, leading to a significant increase in subsequent cleaning and replacement costs.

[0038] In view of this, such as Figures 1 to 5 As shown, the first aspect of the present invention provides a battery system, which includes an immersion tank 10 and a plurality of battery packs 20, and further includes a controller, a temperature measuring component, a control valve group, a sprinkler pipe 30, a thermal management module and a fire protection module.

[0039] The immersion tank 10 is filled with coolant, and the top of the immersion tank 10 is open. The multiple battery packs 20 are housed inside the immersion tank 10 and immersed in the coolant.

[0040] The battery pack 20 includes a housing 22 and a plurality of batteries 21. The housing 22 has an interior cavity containing coolant. The top of the housing 22 has an opening, and the plurality of batteries 21 are housed in the cavity and immersed in the coolant.

[0041] The spray pipes 60 are arranged one-to-one in the cavities of each battery pack 20. The thermal management module and the fire protection module are selectively connected to the spray pipes 30 in each battery pack 20 through the control valve group. The temperature measuring component is used to measure the temperature of the battery 21 in each battery pack 20. The controller is used to control the control valve group to open or close according to the temperature of the battery 21.

[0042] In some embodiments, the thermal management module includes a thermal management inlet pipe 40, a thermal management return pipe 41, a thermal management heat exchanger, a thermal management liquid storage tank, a thermal management drive pump, and a refrigeration unit.

[0043] The outlet of the thermal management inlet pipe 40 is connected to the spray pipe 30 in each of the battery packs 20. The outlet of the thermal management return pipe 41 is sequentially connected to the thermal management drive pump, the thermal management storage tank, the secondary side of the thermal management heat exchanger, and the inlet of the thermal management inlet pipe 40. The primary side of the thermal management heat exchanger is connected to the refrigeration unit. A return pipe 60 is also provided in the battery pack 20, and the thermal management return pipe 41 is connected to the outlet of the return pipe 60 in each of the battery packs 20.

[0044] In some embodiments, the fire protection module includes a fire-fighting storage tank, a fire-fighting heat exchanger, a fire-fighting drive pump, and a pumping pump; the inlet of the fire-fighting return pipeline 51 is connected to the outlet of the return pipeline 60 in each of the battery packs 20, and the outlet of the fire-fighting return pipeline 51 is sequentially connected to the fire-fighting drive pump, the fire-fighting storage tank, the secondary side of the fire-fighting heat exchanger, and the inlet of the fire-fighting return pipeline 51; the primary side of the fire-fighting heat exchanger is connected to the refrigeration unit; the bottom of the immersion tank 10 is provided with a liquid outlet, and the liquid outlet of the immersion tank 10 is sequentially connected to the pumping pump and the heat management storage tank.

[0045] In some embodiments, the thermal management liquid inlet pipeline 40 includes a thermal management liquid inlet main pipe, thermal management liquid inlet branch pipes and thermal management liquid inlet control valve 401. The thermal management liquid inlet branch pipes are connected to the spray pipes 30 in each of the battery packs 20 in a one-to-one correspondence, and each thermal management branch pipe is connected to the thermal management main pipe.

[0046] The fire-fighting liquid inlet pipeline 50 includes a fire-fighting liquid inlet main pipe and multiple fire-fighting liquid inlet branch pipes. Each fire-fighting liquid inlet branch pipe is connected to a corresponding sprinkler pipe 30 in each of the battery packs 20, and each fire-fighting branch pipe is connected to the fire-fighting main pipe.

[0047] In some embodiments, the thermal management return liquid pipeline 41 includes a thermal management return liquid main pipe, thermal management return liquid branch pipes and thermal management return liquid control valve 411. The thermal management return liquid branch pipes are connected to the spray pipelines 30 in each of the battery packs 20 in a one-to-one correspondence, and each of the thermal management branch pipes is connected to the thermal management main pipe.

[0048] The fire return pipeline 51 includes a main fire return pipeline and multiple branch fire return pipelines. Each branch fire return pipeline is connected to a corresponding sprinkler pipeline 30 in each of the battery packs 20, and each branch fire pipeline is connected to the main fire pipeline.

[0049] In some embodiments, the multiple batteries 21 in the battery pack 20 are arranged in an array. The spray pipe 30 includes a main inlet pipe 32 and multiple spray branch pipes 33. The spray branch pipes 33 are arranged one-to-one on the top of each row of batteries 21 and extend in the direction of the row. The spray branch pipes 33 have multiple spray holes on the side facing the battery 21. One end of the main inlet pipe 32 extends out of the housing 22 and is connected to the thermal management liquid inlet pipe 40 and the fire protection liquid inlet pipe 50. The other end of the main inlet pipe 32 is located inside the housing 22 and is connected to each of the spray branch pipes 33.

[0050] In some embodiments, the return pipe 60 includes a first pipe section 61 and a second pipe section 62. The first pipe section 61 extends along the row direction of a plurality of arrayed batteries, and a plurality of spaced return holes 610 are provided on the first pipe section 61. One end of the second pipe is connected to the first pipe section 61, and the other end of the second pipe extends out of the housing 22 and communicates with the thermal management return pipe 41 and the fire protection return pipe 51.

[0051] In some embodiments, the control valve group includes a spray control valve 31, a thermal management inlet control valve 401, a fire-fighting inlet control valve 501, a thermal management return control valve 411, a fire-fighting return control valve 511, and a suction valve; the spray control valve 31 is provided on the spray branch pipe, the thermal management inlet control valve 401 is provided on the thermal management branch pipe, the fire-fighting inlet control valve 501 is provided on each of the fire-fighting branch pipes, the thermal management return control valve 411 is provided on each of the thermal management branch pipes, the fire-fighting return control valve 511 is provided on each of the fire-fighting branch pipes, and the suction valve is provided at the outlet of the immersion tank 10;

[0052] The temperature measuring component includes multiple temperature sensors, each of which is used to measure the temperature of each of the batteries 21. The controller controls the on / off state of the spray control valve 31, the thermal management liquid inlet control valve 401, the fire-fighting liquid inlet control valve 501, the thermal management liquid return control valve 411, the fire-fighting liquid return control valve 511, and the extraction valve according to the temperature of each of the batteries 21.

[0053] In some embodiments, the device further includes a mounting frame having a plurality of stacked mounting slots, in which the battery packs 20 are disposed one-to-one; the plurality of battery packs 20 are stacked on the mounting frame to form battery clusters, and at least two battery clusters are disposed in the housing 10.

[0054] Specifically, the battery clusters and piping structures (thermal management inlet pipe 40, fire-fighting inlet pipe 50, thermal management return pipe 41, and fire-fighting return pipe 51) are all immersed in the immersion tank. The battery clusters can consist of 2, 3, or 4 layers of battery packs, and are placed horizontally in the immersion tank. Multiple battery clusters are placed in the immersion tank along its length. In this embodiment, each battery pack uses 13 batteries as a row, and each battery pack has an array arrangement of 4 rows. Each battery pack is filled with coolant, and a spray pipe 30 is arranged inside the battery pack and above the batteries. One spray pipe 30 is set above each row of batteries, and multiple spray holes are set on the side of the spray pipe 30 facing the top surface of the battery. The diameter of the spray holes ranges from 4 to 20 mm. The spray pipes above each battery can be designed as a group of two. The top opening of each battery pack can be equipped with a cover or not. The cover structure can be designed as a strictly sealed structure or a non-sealed structure. This design schematic does not include a top cover structure. The space between each battery pack and the immersion tank is filled with coolant, which is of the same type as the coolant inside the battery pack. The coolant can be an electrically insulating liquid such as fluorinated liquid, synthetic oil, ester, or silicone oil. As a preferred design for thermal runaway suppression and thermal management, the immersion fluid in this design example is modified silicone oil to cope with the extremely high temperatures during the thermal runaway suppression process.

[0055] A second aspect of the present invention provides a thermal management method applied to a battery system as provided in the first aspect of the present invention, comprising the following steps:

[0056] Step S110: Real-time detection of the temperature of each battery, and obtaining the temperature change rate of each battery based on the temperature of each battery, wherein the temperature change rate is the rate at which the battery temperature changes with time per unit time.

[0057] Step S120: If the temperature change rate of the battery is greater than the preset maximum temperature change rate, determine the battery pack to which the battery belongs based on the preset correspondence between the battery and the battery pack.

[0058] Step S130: After controlling all batteries in the battery pack to be powered off for a preset time, control the closing of the thermal management liquid inlet control valve and thermal management liquid return control valve corresponding to the battery pack, open the fire-fighting liquid inlet control valve and fire-fighting liquid return control valve corresponding to the battery pack, open the spray control valve corresponding to the battery; and control the opening of the drain valve of the housing.

[0059] Specifically, under normal operating conditions, the thermal management module exchanges heat with the refrigeration unit to stabilize the temperature of the coolant supplied to the immersion tank at a low level, such as 25°C. The thermal management module's delivery pump supplies coolant to each battery pack within the immersion tank. At this time, the fire suppression module's pump remains off, and all valves in the fire suppression module remain closed. All inlet and outlet valves in the thermal management module's piping are fully open, as are all valves in each battery group within the battery pack. The cooled immersion liquid is evenly sprayed onto the top of each battery, carrying away the heat generated by the battery. The heated coolant then flows back to the thermal management module from the outlet pipe for cooling circulation. During this stage, the controller continuously monitors and records parameters of each battery, such as temperature, temperature rise rate, voltage, and combustible material concentration, and compares these parameters with preset thresholds in the controller to continuously monitor the battery's health status.

[0060] In other feasible embodiments, when a single battery experiences abnormal temperature or an abnormal rate of temperature rise, it indicates that the battery is in a self-heating phase and may subsequently experience thermal runaway. For example, if the seventh battery in the second row of batteries within the first battery pack experiences an abnormal rate of temperature rise, the thermal management control module detects that the maximum rate of temperature rise in the system exceeds a threshold, reports an abnormal cell status, and marks and locates the abnormal battery according to the pre-set correspondence between each battery and the battery pack. Simultaneously, the controller module outputs a signal to disconnect the circuit breakers of each level of the battery pack, immersing the battery cluster in the tank to stop battery charging and discharging; at this time, all valves in the thermal management module pipeline remain fully open, and thermal management operates normally. Next, the control module locates the battery pack containing the abnormal battery and the battery row (e.g., the second row) within the battery pack according to the pre-set correspondence between each battery and the battery pack; it identifies the relevant valves as the thermal management inlet control valve, the thermal management outlet valve, the fire-fighting inlet control valve, the fire-fighting return control valve, and the spray control valve of the corresponding spray pipe on the second row of batteries in the battery pack.

[0061] Subsequently, the thermal management module shuts down, closing all inlet and outlet valves of the battery pack thermal management module pipelines. Simultaneously, the fire suppression module is activated, maintaining maximum power output, and the fire suppression inlet and return control valves for this battery pack are opened; the spray control valve of the spray pipe above the second row of batteries in this battery pack is opened, and the valves of the thermal management module are closed; at this time, the fire suppression module performs targeted spray cooling on this row of batteries. Simultaneously, the immersion tank drain valve is opened, and the pump is activated at full power to pump the immersion liquid back to the thermal management module's storage tank. At this point, the liquid level in the immersion tank and battery pack compartments begins to drop rapidly. However, because all valves are closed and the bottoms are sealed, a large amount of immersion liquid remains in each battery pack compartment to continue cooling the residual heat of the batteries that have stopped charging and discharging, and to isolate the compartments from each other to prevent coolant contamination. This continues until the liquid level in the immersion tank reaches the set level, at which point the outside of the battery pack compartments is exposed to the outside atmosphere, and the pump valve is closed. During the continuous cooling process of the fire suppression module, the controller continuously monitors parameters such as the target battery temperature, temperature rise rate, and combustible gas concentration. It determines whether the target battery temperature rise rate has decreased to the target rate. If not, it continues to operate at maximum power. If so, the controller adjusts the power output to normal power and continues to monitor parameters such as the temperature rise rate. Then, during the continuous cooling process, the control module continuously determines whether the target battery temperature has decreased to the target temperature. If so, the fire suppression module continues to operate at normal power and further determines whether the combustible gas concentration has decreased to the target concentration. If not, the fire suppression module continues to operate at normal power until the temperature decreases to the target temperature. When the controller determines that all monitored parameters have decreased to acceptable levels, the fire suppression module unit shuts down and closes all operating valves. At this time, the temperature inside the battery box returns to normal, awaiting maintenance personnel to enter the box to replace the battery.

[0062] This invention features a hydraulically balanced, non-sealed design for each battery pack: Utilizing the overall immersion tank and battery pack enclosure design, it avoids the need for pressure-bearing sealing within each battery pack, reduces hydraulic imbalance, and prevents system unreliability under high pressure. Point-to-point spray fire suppression: Employing liquid valves within the battery pack and a top-mounted spray pipeline design, combined with a controller, it enables point-to-point spraying. Preventing cross-contamination of immersion coolant and reducing maintenance costs: Using multiple valve openings and a drainage design within the immersion tank, the liquid in each battery pack enclosure is isolated, allowing for independent operation of the fire suppression liquid and preventing cost increases due to contamination.

[0063] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.

Claims

1. A battery system comprising an immersion tank (10) and a plurality of battery packs (20), characterized in that, It also includes a controller, temperature measurement components, control valve assembly, sprinkler pipe (30), thermal management module and fire protection module; The immersion tank (10) is filled with coolant, and the top of the immersion tank (10) is open. The multiple battery packs (20) are housed inside the immersion tank (10) and immersed in the coolant. The battery pack (20) includes a housing (22) and a plurality of batteries (21). The housing (22) has an interior cavity containing coolant. The top of the housing (22) has an opening, and the plurality of batteries (21) are housed in the cavity and immersed in the coolant. The spray pipes (60) are arranged one-to-one in the cavities of each battery pack (20). The thermal management module and the fire protection module are selectively connected to the spray pipes (30) in each battery pack (20) through the control valve group. The temperature measuring component is used to measure the temperature of the battery (21) in each battery pack (20). The controller is used to control the control valve group to open or close according to the temperature of the battery (21).

2. The battery system according to claim 1, characterized in that, The thermal management module includes a thermal management inlet pipe (40), a thermal management return pipe (41), a thermal management heat exchanger, a thermal management storage tank, a thermal management drive pump, and a refrigeration unit. The outlet of the thermal management liquid inlet pipe (40) is connected to the spray pipe (30) in each of the battery packs (20). The outlet of the thermal management liquid return pipe (41) is sequentially connected to the thermal management drive pump, the thermal management liquid storage tank, the secondary side of the thermal management heat exchanger and the inlet of the thermal management liquid inlet pipe (40). The primary side of the thermal management heat exchanger is connected to the refrigeration unit. A liquid return pipe (60) is also provided in the battery pack (20). The thermal management liquid return pipe (41) is connected to the outlet of the liquid return pipe (60) in each of the battery packs (20).

3. A battery system according to claim 2, characterized in that, The fire protection module includes a fire-fighting storage tank, a fire-fighting heat exchanger, a fire-fighting drive pump, and a pumping pump; the inlet of the fire-fighting return pipeline (51) is connected to the outlet of the return pipeline (60) in each of the battery packs (20), and the outlet of the fire-fighting return pipeline (51) is sequentially connected to the fire-fighting drive pump, the fire-fighting storage tank, the secondary side of the fire-fighting heat exchanger, and the inlet of the fire-fighting return pipeline (51), and the primary side of the fire-fighting heat exchanger is connected to the refrigeration unit; the bottom of the immersion tank (10) is provided with a liquid outlet, and the liquid outlet of the immersion tank (10) is sequentially connected to the pumping pump and the heat management storage tank.

4. A battery system according to claim 3, characterized in that, The thermal management liquid inlet pipeline (40) includes a thermal management liquid inlet main pipe, thermal management liquid inlet branch pipes and thermal management liquid inlet control valve (401). The thermal management liquid inlet branch pipes are connected one-to-one with the spray pipes (30) in each of the battery packs (20), and each thermal management branch pipe is connected to the thermal management main pipe. The fire-fighting liquid inlet pipeline (50) includes a fire-fighting liquid inlet main pipe and multiple fire-fighting liquid inlet branch pipes. The fire-fighting liquid inlet branch pipes are connected one-to-one with the spray pipes (30) in each of the battery packs (20), and each of the fire-fighting branch pipes is connected to the fire-fighting main pipe.

5. A battery system according to claim 4, characterized in that, The thermal management return pipeline (41) includes a thermal management return main pipe, thermal management return branch pipes and thermal management return control valve (411). The thermal management return branch pipes are connected one-to-one with the spray pipelines (30) in each of the battery packs (20), and each thermal management branch pipe is connected to the thermal management main pipe. The fire return pipeline (51) includes a fire return main pipe and multiple fire return branch pipes. The fire return branch pipes are connected one-to-one with the sprinkler pipelines (30) in each of the battery packs (20), and each of the fire branch pipes is connected to the fire main pipe.

6. A battery system according to claim 5, characterized in that, The battery pack (20) contains a plurality of batteries (21) arranged in an array. The spray pipe (30) includes a main inlet pipe (32) and a plurality of spray branch pipes (33). The spray branch pipes (33) are arranged one-to-one on the top of each row of batteries (21) and extend in the direction of the row. The spray branch pipes (33) have a plurality of spray holes on the side facing the battery (21). One end of the main inlet pipe (32) extends out of the housing (22) and is connected to the thermal management liquid inlet pipe (40) and the fire-fighting liquid inlet pipe (50). The other end of the main inlet pipe (32) is located inside the housing (22) and is connected to each of the spray branch pipes (33).

7. A battery system according to claim 5, characterized in that, The return pipe (60) includes a first pipe section (61) and a second pipe section (62). The first pipe section (61) extends along the row direction of the multiple array-arranged batteries. The first pipe section (61) is provided with multiple spaced return holes (610). One end of the second pipe is connected to the first pipe section (61), and the other end of the second pipe extends out of the housing (22) and communicates with the thermal management return pipe (41) and the fire protection return pipe (51).

8. A battery system according to claim 5, characterized in that, The control valve group includes a spray control valve (31), a thermal management inlet control valve (401), a fire-fighting inlet control valve (501), a thermal management return control valve (411), a fire-fighting return control valve (511), and a suction valve; the spray branch pipe is equipped with a spray control valve (31), the thermal management branch pipe is equipped with a thermal management inlet control valve (401), the fire-fighting branch pipe is equipped with a fire-fighting inlet control valve (501), the thermal management branch pipe is equipped with a thermal management return control valve (411), the fire-fighting branch pipe is equipped with a fire-fighting return control valve (511), and the outlet of the immersion tank (10) is equipped with the suction valve; The temperature measuring component includes multiple temperature sensors, each of which is used to measure the temperature of each of the batteries (21); the controller controls the on / off state of the spray control valve (31), the thermal management liquid inlet control valve (401), the fire-fighting liquid inlet control valve (501), the thermal management liquid return control valve (411), the fire-fighting liquid return control valve (511), and the liquid extraction valve according to the temperature of each of the batteries (21).

9. The battery system according to any one of claims 1-8, characterized in that, It also includes a mounting frame, which has multiple stacked mounting slots, and the battery packs (20) are respectively disposed in the mounting slots; multiple battery packs (20) are stacked on the mounting frame to form battery clusters, and at least two battery clusters are disposed in the housing (10).

10. A thermal management method, characterized in that, The battery system applied as described in any one of claims 1-9 includes the following steps: The temperature of each battery is detected in real time, and the temperature change rate of each battery is obtained based on the temperature of each battery. The temperature change rate is the rate at which the temperature of the battery changes with time per unit time. If the rate of temperature change of the battery is greater than the preset maximum rate of temperature change, the battery pack to which the battery belongs is determined according to the preset correspondence between batteries and battery packs. After controlling all batteries in the battery pack to be powered off for a preset time, the thermal management liquid inlet control valve and thermal management liquid return control valve corresponding to the battery pack are closed, the fire-fighting liquid inlet control valve and fire-fighting liquid return control valve corresponding to the battery pack are opened, the spray control valve corresponding to the battery is opened, and the drain valve of the housing is opened.

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