A fire control method for energy storage box and a fire control system

Abstract

The present invention provides a fire control method and a fire control system for an energy storage box, comprising the following steps: S1: obtaining a first state parameter of a battery cell, and executing a first-level fire strategy when the first state parameter meets a thermal runaway condition of the battery cell; S2: obtaining a second state parameter of a battery pack to which the battery cell belongs, and executing a second-level fire strategy when the second state parameter meets a thermal runaway condition of the battery pack; S3: obtaining a first operating state of the battery pack, and executing a third-level fire strategy when the first operating state meets a heat spread condition; S4: obtaining a second operating state of a container to which the battery pack belongs, and executing a fourth-level fire strategy when the second operating state meets a heat spread condition. The fire control method sets fire judgment conditions and fire strategies for each level to ensure that the energy storage box can perform fire control from the occurrence of thermal runaway of the battery cell, which is conducive to transient fire judgment and processing.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a fire control system and a control method for an energy storage box. Background Art

[0002] With the development of energy storage technology, energy storage boxes are being used more and more widely. However, the charge and discharge cycle life and safety of the cells in the energy storage box are greatly affected by temperature. When the cell temperature is too high or the temperature difference is large, the cell cycle life will drop significantly, affecting the service life of the energy storage product. In severe cases, it will cause thermal runaway of the cell, and even cause explosion and fire. The energy storage box receives the information feedback from the detector through the battery management system to determine whether the temperature of the battery cluster is too high and whether there is a fire in the container; however, before the fire occurs in the energy storage box, there are the thermal runaway stage of the cell, the thermal runaway stage of the battery pack, and the thermal spread stage of the battery pack; the heat released by the thermal runaway of a single cell is limited and will not cause too serious harm, but the thermal runaway of the cell or battery pack will quickly spread to the surrounding cells or battery packs, and the adjacent cells or battery packs will successively transfer the heat generated by the thermal runaway, causing a "domino effect". Therefore, the fire monitoring and judgment method of the traditional fire control method of the energy storage box has the problem of high hysteresis, and it is impossible to start fire control from the thermal runaway of the cell. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a fire control system and a control method for an energy storage box, so as to solve the problem that the fire monitoring and judgment method of the traditional fire control method for the energy storage box has high lag and low reliability.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a fire control method for an energy storage box, comprising the following steps:

[0005] S1: Obtaining a first state parameter of the battery cell, and executing a first-level fire fighting strategy when the first state parameter meets a condition of thermal runaway of the battery cell; wherein the first state parameter includes a battery cell temperature of the battery cell, a battery cell voltage of the battery cell, and a deformation amount of an explosion relief valve of the battery cell;

[0006] S2: obtaining a second state parameter of the battery pack to which the battery cell belongs, and executing a secondary fire fighting strategy when the second state parameter meets a thermal runaway condition of the battery pack; wherein the second state parameter includes an air pressure inside the battery pack and a flammable gas concentration inside the battery pack;

[0007] S3: Acquire a first operating state of the battery pack, and when the first operating state meets a heat spread condition, execute a third-level fire protection strategy;

[0008] S4: Obtain a second operating state of the container to which the battery pack belongs, and when the second operating state meets a heat diffusion condition, execute a level 4 fire protection strategy.

[0009] Furthermore, in the step S1, a first state parameter of the battery cell is obtained, and when the first state parameter meets the thermal runaway condition of the battery cell, a first-level fire fighting strategy is executed, which specifically includes the following steps:

[0010] S11: respectively obtaining a first state parameter of the battery cell at a first moment and a first state parameter of the battery cell at a second moment, where the second moment is a moment after the first moment;

[0011] S12: Determine whether the first state parameter of the battery cell at the first moment and the second state parameter of the battery cell at the second moment meet the first preset condition; if so, proceed to step S13; if not, repeat steps S11 to S12;

[0012] S13: Determine whether the first state parameter of the battery cell at the first moment and the second state parameter of the battery cell at the second moment meet the second preset condition; if so, proceed to step S14; if not, repeat steps S11 to S12;

[0013] S14: disconnecting the charge and discharge circuit of the battery cell.

[0014] Furthermore, the first preset condition includes satisfying the following conditions at the same time:

[0015]

[0016]

[0017]

[0018] in, For the first moment, is the cell temperature of the cell at the first moment, is the cell voltage of the cell at the first moment, is the deformation amount of the explosion relief valve of the battery cell at the first moment, For the second moment, is the cell temperature of the cell at the second moment, is the cell voltage of the cell at the second moment, is the deformation amount of the explosion relief valve of the battery cell at the second moment, is the preset temperature change rate, is the preset voltage change rate, is the preset deformation rate;

[0019] The second preset condition includes satisfying at least one of the following conditions:

[0020]

[0021]

[0022] in, To preset the maximum temperature of the battery cell, It is the preset minimum voltage of the battery cell.

[0023] Furthermore, in the step S2, a second state parameter of the battery pack to which the battery cell belongs is obtained, and when the second state parameter meets the thermal runaway condition of the battery pack, a secondary fire fighting strategy is executed, which specifically includes the following steps:

[0024] S21: respectively obtaining a second state parameter of the battery pack at a third moment and a second state parameter of the battery pack at a fourth moment, wherein the third moment is a moment next to the fourth moment;

[0025] S22: Determine whether the second state parameter of the battery pack at the third moment and the second state parameter of the battery pack at the fourth moment meet a third preset condition; if so, proceed to step S23; if not, repeat steps S21 to S22;

[0026] S23: Determine whether the second state parameter of the battery pack at the third moment and the second state parameter of the battery pack at the fourth moment meet a fourth preset condition; if so, proceed to step S24; if not, repeat steps S21 to S22;

[0027] S24: disconnecting the charging and discharging circuits of all the cells in the battery pack, spraying fire-fighting agents into the interior of the battery pack through a fire-fighting pipe, and releasing inert gas into the interior of the container until the oxygen concentration inside the container is lower than a preset concentration.

[0028] Furthermore, the third preset condition includes satisfying the following conditions at the same time:

[0029]

[0030]

[0031] in, For the third moment, is the gas pressure inside the battery pack at the third moment, is the combustible gas concentration inside the battery pack at the third moment, For the fourth moment, is the gas pressure inside the battery pack at the fourth moment, is the combustible gas concentration inside the battery pack at the fourth moment, is the preset air pressure change rate, It is the preset rate of change of the concentration of combustible gas;

[0032] The fourth preset condition includes satisfying at least one of the following conditions:

[0033]

[0034]

[0035] in, To preset the maximum air pressure, It is the preset maximum combustible gas concentration.

[0036] Furthermore, in step S3, the first operating state of the battery pack is obtained, and when the first operating state meets the heat spread condition, a three-level fire protection strategy is executed, specifically including:

[0037] The first state parameters of all the battery cells in the battery pack are obtained respectively; when the first state parameters of two adjacent battery cells both meet the battery cell thermal runaway condition, the first operating state meets the heat spread condition, and the liquid cooling mechanism cools the battery cluster to which the battery pack belongs.

[0038] Furthermore, in step S4, the second operating state of the container to which the battery pack belongs is obtained. When the second operating state meets the heat diffusion condition, a four-level fire fighting strategy is executed, which specifically includes:

[0039] The fire information inside the container is obtained. When a flame appears in the container, the second operating state satisfies the heat diffusion condition. The nozzle sprays the fire extinguishing agent to the battery cluster to extinguish the flame. When the nozzle sprays the fire extinguishing agent and the flame is not extinguished, the watering mechanism pours water into the container.

[0040] Another object of the present invention is to provide a fire control system for an energy storage box, wherein the energy storage box includes a container and a plurality of battery clusters arranged in the container, the battery cluster includes a plurality of battery packs, the battery pack includes a plurality of battery cells, and the fire control system is used to execute the above-mentioned fire control method, the fire control system includes a first-level fire module for fire control of the battery cells, a second-level fire module for fire control of the battery packs, a third-level fire module for fire control of the battery clusters, and a fourth-level fire module for fire control of the container.

[0041] Furthermore, the first-level fire protection module includes a deformation detector, a temperature detector and a voltage detector. The deformation detector is arranged on the explosion-proof valve of the battery cell, and the temperature detector and the voltage detector are respectively arranged on two electrode columns of the battery cell.

[0042] Furthermore, the secondary fire protection module includes an air pressure sensor, a combustible gas sensor, a fire protection pipe, an inert gas injection pipe and an oxygen concentration detection device. The air pressure sensor and the combustible gas sensor are both arranged in the battery pack. The container is provided with a pressure relief port. The oxygen concentration detection device is arranged in the pressure relief port. The fire protection pipe is arranged in the container. The battery pack is provided with a connecting port. The fire protection pipe is connected to the connecting port.

[0043] The beneficial effects of the present invention are as follows: the fire control method provided by the present invention establishes control architectures of level one to level four fire control systems corresponding to the battery cells, battery packs, battery clusters and containers of the energy storage box, and the fire control method sets fire judgment conditions and fire strategies corresponding to each level to ensure that the energy storage box can perform fire control from the occurrence of thermal runaway of low-level energy storage elements, which is beneficial to transient fire judgment and processing, ensures that the execution of the fire strategy is synchronized with the thermal runaway state and fire state of the energy storage element of the energy storage box, and reduces damage to the energy storage element during the execution of the fire control method, thereby avoiding damage to the energy storage box and inconvenience in use due to the fire control method being triggered by mistake. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A flow chart of the fire control method of the present invention;

[0045] Figure 2 The structure diagram of the battery core of the energy storage box of the fire control system provided by the present invention is schematically shown;

[0046] Figure 3 The battery pack structure diagram of the energy storage box of the fire control system provided by the present invention is schematically shown;

[0047] Figure 4 Schematically shows Figure 3 A plurality of battery cells arranged adjacent to each other in a battery pack;

[0048] Figure 5 The structure diagram of a container using an energy storage box of the fire control system provided by the present invention is schematically shown at one viewing angle;

[0049] Figure 6 The structure of a container using an energy storage box of the fire control system provided by the present invention is schematically shown from another perspective.

[0050] Description of labels:

[0051] 1. Battery cell; 2. Battery cell pole; 3. Battery cell explosion relief valve; 4. Deformation detector; 5. Temperature detector; 6. Voltage detector; 7. Battery pack; 8. Air pressure sensor and combustible gas sensor; 9. Fire protection pipe; 10. Inert gas injection pipe; 11. Oxygen concentration detection device; 12. Container; 13. Pressure relief port; 14. Connection port; 15. Water inlet; 16. Liquid cooling pipeline; 17. Liquid cooling valve; 18. Camera; 19. Nozzle; 20. Water immersion sensor; 21. Battery cluster; 22. Pipeline valve. DETAILED DESCRIPTION

[0052] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0053] Reference Figures 2 to 6 The energy storage box is provided with energy storage elements according to the following architecture: a plurality of battery clusters 21 are provided in the container 12 , a plurality of battery packs 7 are provided in the battery clusters 21 , and a plurality of battery cells 1 are provided in the battery packs 7 .

[0054] In the traditional fire control system of the energy storage box, the battery management system receives the information fed back by the detector to judge the internal state of the container 12, and directly uses water to extinguish the fire when a fire is detected inside the container 12. However, before the fire occurs in the energy storage box, there are the thermal runaway stage of the battery cell 1, the thermal runaway stage of the battery pack 7, and the thermal spread stage of the battery pack 7; the heat released by the thermal runaway of a single battery cell 1 is limited and will not cause too serious harm, but the thermal runaway of the battery cell 1 or battery pack 7 will quickly spread to the surrounding battery cells 1 or battery pack 7, and the adjacent battery cells 1 or battery pack 7 will successively transfer the heat generated by the thermal runaway, and also experience thermal runaway, triggering a "domino effect" and causing the energy storage box to enter the thermal diffusion stage.

[0055] The fire management system of the traditional energy storage box simply cools the battery cluster 21 through a liquid cooling mechanism and extinguishes the fire in the container 12 through a water filling system. The fire control method of the traditional energy storage box has a high lag and cannot perform corresponding firefighting actions for the thermal runaway stage of the battery cell 1 or the thermal runaway stage of the battery pack 7. The reliability of this traditional fire control method is low. The energy storage box is not cooled or extinguished until heat spreads or diffuses inside the energy storage box, which easily damages the energy storage elements of the energy storage box.

[0056] To solve this problem, please refer to Figure 1 This embodiment designs a fire control method for an energy storage box, which includes the following steps:

[0057] S1: Obtaining a first state parameter of the battery cell, and executing a first-level fire fighting strategy when the first state parameter meets a condition of thermal runaway of the battery cell; wherein the first state parameter includes a battery cell temperature of the battery cell, a battery cell voltage of the battery cell, and a deformation amount of an explosion relief valve of the battery cell;

[0058] S2: obtaining a second state parameter of the battery pack to which the battery cell belongs, and executing a secondary fire fighting strategy when the second state parameter meets a thermal runaway condition of the battery pack; wherein the second state parameter includes an air pressure inside the battery pack and a flammable gas concentration inside the battery pack;

[0059] S3: Acquire a first operating state of the battery pack, and when the first operating state meets a heat spread condition, execute a third-level fire protection strategy;

[0060] S4: Obtain a second operating state of the container to which the battery pack belongs, and when the second operating state meets a heat diffusion condition, execute a level 4 fire protection strategy.

[0061] The fire control method provided in the present invention sets four levels of fire monitoring conditions in sequence according to the order in which the energy storage elements in the energy storage box induce thermal runaway, and can execute four levels of fire strategies respectively according to the four fire monitoring conditions.

[0062] In order to implement the above-mentioned fire control method, the present invention also designs a fire control system for an energy storage box, which includes a first-level fire control module for fire control of the battery cell 1, a second-level fire control module for fire control of the battery pack 7, a third-level fire control module for fire control of the battery cluster 21, and a fourth-level fire control module for fire control of the container 12.

[0063] Thermal runaway of battery cell 1 is usually caused by two reasons: internal short circuit and strong redox reaction between positive electrode material and electrolyte. Therefore, when thermal runaway occurs in battery cell 1, the voltage of battery cell 1 will drop sharply, the temperature of battery cell 1 will rise sharply, and the explosion-proof valve of battery cell 1 will be deformed.

[0064] Please refer to Figure 2 The first-level fire protection module of the fire control system provided in the embodiment is designed for the above-mentioned characteristics of thermal runaway of the battery cell 1, and includes: a deformation detector 4, a temperature detector 5 and a voltage detector 6. The deformation detector 4 is arranged on the explosion-proof valve of the battery cell 1, and the temperature detector 5 and the voltage detector 6 are respectively arranged on the two electrode columns 2 of the battery cell 1. The temperature detector 5 is used to obtain the temperature of the battery cell 1, the voltage detector 6 is used to obtain the voltage of the battery cell 1, and the deformation detector is used to obtain the deformation of the explosion-proof valve. Therefore, in step S1 of the fire control method provided in this embodiment, the first state parameter of the battery cell 1 includes: the temperature of the battery cell 1, the voltage of the battery cell 1 and the deformation of the explosion-proof valve.

[0065] In this embodiment, in step S1, a first state parameter of the battery cell is obtained. When the first state parameter meets the thermal runaway condition of the battery cell, a first-level fire fighting strategy is executed, which specifically includes the following steps:

[0066] S11: respectively obtaining a first state parameter of the battery cell at a first moment and a first state parameter of the battery cell at a second moment, where the second moment is a moment after the first moment;

[0067] S12: Determine whether the first state parameter of the battery cell at the first moment and the second state parameter of the battery cell at the second moment meet the first preset condition; if so, proceed to step S13; if not, repeat steps S11 to S12;

[0068] S13: Determine whether the first state parameter of the battery cell at the first moment and the second state parameter of the battery cell at the second moment meet the second preset condition; if so, proceed to step S14; if not, repeat steps S11 to S12;

[0069] S14: disconnecting the charge and discharge circuit of the battery cell.

[0070] In detail, the first precondition mentioned above includes satisfying the following conditions at the same time:

[0071]

[0072]

[0073]

[0074] in, For the first moment, is the cell temperature of the cell at the first moment, is the cell voltage of the cell at the first moment, is the deformation amount of the battery cell explosion relief valve 3 of the battery cell at the first moment, For the second moment, is the cell temperature of the cell at the second moment, is the cell voltage of the cell at the second moment, is the deformation amount of the explosion relief valve 3 of the battery cell at the second moment, is the preset temperature change rate, is the preset voltage change rate, is the preset deformation rate;

[0075] The second preset condition includes satisfying at least one of the following conditions:

[0076]

[0077]

[0078] in, To preset the maximum temperature of the battery cell, It is the preset minimum voltage of the battery cell.

[0079] In this embodiment, the first-level fire protection strategy is to disconnect the charging and discharging circuit of the battery cell with thermal runaway.

[0080] When the temperature change rate, voltage change rate and deformation change rate of the battery cell explosion relief valve 3 exceed the preset temperature change rate, voltage change rate and deformation change rate respectively, it can be judged that the battery cell may be in thermal runaway. However, in order to prevent misjudgment and affect the reliability of the energy storage box using the fire control method, when only the first preset condition is met and the second preset condition is not met, the first-level fire strategy is not executed, but steps S11 to S12 are repeatedly executed until the first state parameter at the first moment and the first state parameter at the second moment simultaneously meet the first preset condition and the second preset condition, and then the first-level fire strategy is executed.

[0081] Preferably, after step S14, step S15 is also included: repeating step S11 to determine whether the first state parameter at the first moment and the first state parameter at the second moment do not satisfy the first preset condition and the second preset condition at the same time; if so, restoring the charge and discharge circuit of the battery cell; if not, repeating step S15 until the first state parameter at the first moment and the first state parameter at the second moment do not satisfy the first preset condition and the second preset condition at the same time.

[0082] When a battery cell experiences thermal runaway, the internal air pressure of the battery pack to which it belongs may increase, and flammable gas may be generated inside the battery pack. When the internal air pressure of the battery pack is too high and the concentration of flammable gas is too high, thermal runaway of the battery pack may occur.

[0083] Please refer to Figure 3 The secondary fire protection module of the fire control system provided in this embodiment is designed for the characteristics of thermal runaway of the battery pack 7. The secondary fire protection module includes: an air pressure sensor and a combustible gas sensor 8. The air pressure sensor and the combustible gas sensor 8 are both arranged in the battery pack 7 to obtain the air pressure and combustible gas concentration inside the battery pack 7, respectively. Therefore, in step S2 of the fire control method provided in this embodiment, the second state parameter of the battery pack 7 includes: the air pressure and combustible gas concentration inside the battery cell 1.

[0084] Also, please refer to Figure 5In order to prevent the explosion caused by flames due to thermal runaway of the battery pack 7, in this embodiment, the secondary fire protection module also includes: a fire protection pipe 9, an inert gas injection pipe 10 and an oxygen concentration detection device 11. A pressure relief port 13 is provided on the container 12. The oxygen concentration detection device 11 is arranged in the pressure relief port 13. The fire protection pipe 9 is arranged in the container 12. A connecting port 14 is provided on the battery pack 7. The fire protection pipe 9 is connected to the connecting port 14. The fire protection pipe 9 is used to release a fire extinguishing agent into the battery pack 7. The fire extinguishing agent can be a gaseous agent or a liquid agent.

[0085] In the fire control method provided in this embodiment, in the above step S2, the second state parameter of the battery pack to which the battery cell belongs is obtained, and when the second state parameter meets the thermal runaway condition of the battery pack, the secondary fire control strategy is executed, which specifically includes the following steps:

[0086] S21: respectively obtaining a second state parameter of the battery pack at a third moment and a second state parameter of the battery pack at a fourth moment, wherein the third moment is a moment next to the fourth moment;

[0087] S22: Determine whether the second state parameter of the battery pack at the third moment and the second state parameter of the battery pack at the fourth moment meet a third preset condition; if so, proceed to step S23; if not, repeat steps S21 to S22;

[0088] S23: Determine whether the second state parameter of the battery pack at the third moment and the second state parameter of the battery pack at the fourth moment meet a fourth preset condition; if so, proceed to step S24; if not, repeat steps S21 to S22;

[0089] S24: disconnecting the charging and discharging circuits of all the cells in the battery pack, spraying fire-fighting agents to the battery pack through a fire-fighting pipeline, and releasing inert gas into the interior of the container until the oxygen concentration inside the container is lower than a preset concentration.

[0090] In the present invention, the first moment is associated with the second moment, and the second moment is the next moment of the first moment; the third moment is associated with the fourth moment, and the fourth moment is the next moment of the third moment; however, the third moment is not the next moment of the second moment, and the second moment and the third moment are not associated with each other. In simple terms: the first moment and the second moment are not a moment in step S2, and the third moment and the fourth moment are not a moment in step S1.

[0091] In detail, the third precondition mentioned above includes satisfying the following conditions at the same time:

[0092]

[0093]

[0094] in, For the third moment, is the gas pressure inside the battery pack at the third moment, is the combustible gas concentration inside the battery pack at the third moment, For the fourth moment, is the gas pressure inside the battery pack at the fourth moment, is the combustible gas concentration inside the battery pack at the fourth moment, is the preset air pressure change rate, It is the preset rate of change of the concentration of combustible gas;

[0095] The fourth preset condition includes satisfying at least one of the following conditions:

[0096]

[0097]

[0098] in, To preset the maximum air pressure, It is the preset maximum combustible gas concentration.

[0099] When the pressure change rate and the combustible gas concentration change rate of the battery pack exceed the preset pressure change rate and the preset pressure change rate respectively, it can be judged that the battery pack may have thermal runaway. However, in order to prevent misjudgment and affect the reliability of the energy storage box using the fire control method, when only the third preset condition is met and the fourth preset condition is not met, the secondary fire strategy is not executed, but steps S21 to S22 are repeatedly executed until the second state parameter at the third moment and the second state parameter at the fourth moment simultaneously meet the third preset condition and the fourth preset condition, and then the secondary fire strategy is executed.

[0100] In detail, in this embodiment, the secondary fire fighting strategy includes: (1) disconnecting the charging and discharging circuits of all cells in the battery pack; (2) injecting inert gas into the interior of the container through an inerting device to reduce the oxygen content in the container and reduce the possibility of fire in the container; preferably, the pressure relief port of the container is provided with a fan and an oxygen concentration detection device, the fan can accelerate the discharge of air from the interior of the container, the oxygen concentration detection device can detect the oxygen concentration of the air inside the container, and the oxygen concentration detection device can stop injecting inert gas into the container when it detects that the oxygen concentration is lower than a preset concentration, and the preset concentration can be set to 4%; (3) the fire fighting pipe sprays the fire fighting agent into the battery pack through the connection port of the battery pack to avoid fire inside the battery pack.

[0101] Preferably, in the present embodiment, the fire-fighting pipe 9 is provided with a pipe valve 22 corresponding to each battery cluster 21. When a battery pack 7 thermally runs away, the pipe valve 22 corresponding to the battery cluster 21 to which the battery pack 7 belongs is opened to spray fire-fighting agents on the battery packs 7 of the battery cluster 21, thereby improving the reliability of the secondary fire-fighting strategy and reducing the probability that thermal runaway of a battery pack 7 will cause thermal runaway of other battery packs 7 in the battery cluster 21 to which the battery pack 7 belongs, and cause heat spread to the battery cluster 21.

[0102] like Figure 4 As shown, the battery pack is provided with cells 1-1, 1-2, 1-3, 1-4, and 1-5 arranged in a matrix. For example, when cell 1-3 experiences thermal runaway, any cell adjacent to cell 1-3 also experiences thermal runaway, and it can be determined that the battery pack to which cell 1-3 belongs enters the thermal spread stage. Therefore, in this embodiment, the thermal spread condition includes that the first state parameters of two adjacent cells both meet the cell thermal runaway condition.

[0103] In order to prevent the heat of the battery cluster to which the battery in the heat spread stage belongs from spreading to the surrounding battery clusters, in this embodiment, the three-level fire protection module for fire protection control of the battery cluster includes a liquid cooling pipeline, which is respectively connected to each of the battery clusters, and a plurality of liquid cooling valves are provided on the liquid cooling pipeline.

[0104] The third-level fire protection strategy includes opening only the liquid cooling valves that flow to the battery cluster to which the battery pack experiencing heat spread belongs.

[0105] For ease of understanding, as an example, Figure 6 The container shown includes battery clusters 21-1 to 21-5 arranged in sequence along the liquid cooling pipe near its water inlet, and liquid cooling valves 17-1 to 17-4 are arranged in sequence on the liquid cooling pipe in the direction close to its water inlet. The liquid cooling valve is arranged between two adjacent battery clusters. When the fire control system implements the fourth-level fire strategy, there are the following liquid cooling working conditions:

[0106] (1) When heat spread occurs in a battery pack in the battery cluster 21 - 1 , the liquid cooling valves 17 - 1 to 17 - 4 are opened, and the other liquid cooling valves are closed to cool the battery cluster 21 - 1 with the maximum liquid cooling power;

[0107] (2) When heat spread occurs in a battery pack in the battery cluster 21 - 2 , the liquid cooling valves 17 - 2 to 17 - 4 are opened, and the other liquid cooling valves are closed to cool the battery cluster 21 - 2 with the maximum liquid cooling power;

[0108] (3) When heat spread occurs in a battery pack in the battery cluster 21 - 3 , open the liquid cooling valves 17 - 3 to 17 - 4 , close the other liquid cooling valves, and use the maximum liquid cooling power to cool the battery cluster 21 - 3 ;

[0109] (4) When heat spread occurs in a battery pack in the battery cluster 21 - 4 , the liquid cooling valve 17 - 4 is opened, and other liquid cooling valves are closed to cool the battery cluster 21 - 4 with the maximum liquid cooling power;

[0110] (5) When heat spread occurs in a battery pack in the battery cluster 21 - 5 , all liquid cooling valves are closed and the battery cluster 21 - 5 is cooled with maximum liquid cooling power.

[0111] The three-level fire fighting strategy of this embodiment takes cooling the battery cluster to which the heat-spreading battery pack belongs as the first priority. Controlling the liquid cooling valve by the above method can improve the cooling efficiency of the battery cluster to which the heat-spreading battery pack belongs.

[0112] During the execution of the above three-level fire protection strategy, the temperature of the battery cluster may be monitored to ensure the reliability of the three-level fire protection strategy.

[0113] In this embodiment, when the heat spread cannot be effectively controlled, the battery pack 7 may catch fire and the flames may extend to the inside of the container, causing a fire. At this time, the energy storage box will enter the heat diffusion stage. In this embodiment, for the characteristics of the above heat diffusion stage and the fire extinguishing requirements, please refer to Figure 6 The fourth-level fire control module includes: a water filling mechanism and a camera 18 and a nozzle 19 arranged in the container 12 , and the water filling mechanism is connected to the water filling inlet 15 in the container 12 .

[0114] In step S4 of the fire control method provided in this embodiment, the second operating state of the container to which the battery pack belongs is obtained. When the second operating state meets the heat diffusion condition, the four-level fire protection strategy is executed, which specifically includes:

[0115] The fire information inside the container is obtained. When a flame appears in the container, the second operating state satisfies the heat diffusion condition. The nozzle sprays the fire extinguishing agent to the battery cluster to extinguish the flame. When the nozzle finishes spraying the fire extinguishing agent and the flame is not extinguished, the water filling mechanism fills water into the box body of the energy storage box.

[0116] Specifically, in this embodiment, the image information of the interior of the container is collected by a camera, and whether a flame is present in the container is determined based on the image information. That is, in this embodiment, the heat diffusion condition is that a flame exists in the container.

[0117] In this embodiment, when it is determined that a flame occurs in the container 12, a fire extinguishing agent is sprayed inside the container 12 through the nozzle 19; specifically, the fire extinguishing agent may be a gas fire extinguishing agent such as perfluorohexanone, heptafluoropropane, or a water-based fire extinguishing agent such as fine water mist. After the nozzle 19 has finished spraying the fire extinguishing agent, when it is determined that a flame occurs in the container 12 based on the image information collected by the camera 18, water is poured into the box body of the energy storage box through the water filling mechanism until the water level in the container 12 reaches the position of the water immersion sensor 20 provided on the bracket of the battery cluster 21.

[0118] In summary, the fire control method provided by the present invention establishes level one to level four fire control architectures corresponding to the battery cells, battery packs, battery clusters and containers of the energy storage box, and the fire control method sets fire judgment conditions and fire strategies corresponding to each level to ensure that the energy storage box can start fire control from the occurrence of thermal runaway of low-level energy storage elements, which is beneficial to transient fire judgment and processing, ensures that the execution of the fire strategy is synchronized with the thermal runaway state and fire state of the energy storage elements of the energy storage box, and reduces the damage to the energy storage elements during the execution of the fire control method, so as to avoid damage to the energy storage box and inconvenience in use due to the fire control method being triggered by mistake.

[0119] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A fire control method for an energy storage box, characterized in that: The following steps are involved: S1: Obtaining a first state parameter of the battery cell, and executing a first-level fire fighting strategy when the first state parameter meets a condition of thermal runaway of the battery cell; wherein the first state parameter includes a battery cell temperature of the battery cell, a battery cell voltage of the battery cell, and a deformation amount of an explosion relief valve of the battery cell; S2: obtaining a second state parameter of the battery pack to which the battery cell belongs, and executing a secondary fire fighting strategy when the second state parameter meets a thermal runaway condition of the battery pack; wherein the second state parameter includes an air pressure inside the battery pack and a flammable gas concentration inside the battery pack; S3: Acquire a first operating state of the battery pack, and when the first operating state meets a heat spread condition, execute a third-level fire protection strategy; S4: Acquire a second operating state of the container to which the battery pack belongs, and when the second operating state meets the heat diffusion condition, execute a level 4 fire protection strategy; In the step S1, a first state parameter of the battery cell is obtained. When the first state parameter meets the thermal runaway condition of the battery cell, a first-level fire fighting strategy is executed, which specifically includes the following steps: S11: respectively obtaining a first state parameter of the battery cell at a first moment and a first state parameter of the battery cell at a second moment, where the second moment is a moment after the first moment; S12: Determine whether the first state parameter of the battery cell at the first moment and the second state parameter of the battery cell at the second moment meet the first preset condition; if so, proceed to step S13; if not, repeat steps S11 to S12; S13: Determine whether the first state parameter of the battery cell at the first moment and the second state parameter of the battery cell at the second moment meet the second preset condition; if so, proceed to step S14; if not, repeat steps S11 to S12; S14: disconnecting the charge and discharge circuit of the battery cell; The first preset condition includes satisfying the following conditions at the same time: in, For the first moment, is the cell temperature of the cell at the first moment, is the cell voltage of the cell at the first moment, is the deformation amount of the explosion relief valve of the battery cell at the first moment, For the second moment, is the cell temperature of the cell at the second moment, is the cell voltage of the cell at the second moment, is the deformation amount of the explosion relief valve of the battery cell at the second moment, is the preset temperature change rate, is the preset voltage change rate, is the preset deformation rate; The second preset condition includes satisfying at least one of the following conditions: in, To preset the maximum temperature of the battery cell, It is the preset minimum voltage of the battery cell.

2. The fire control method according to claim 1, characterized in that: In the step S2, a second state parameter of the battery pack to which the battery cell belongs is obtained. When the second state parameter meets the thermal runaway condition of the battery pack, a secondary fire fighting strategy is executed, which specifically includes the following steps: S21: respectively obtaining a second state parameter of the battery pack at a third moment and a second state parameter of the battery pack at a fourth moment, wherein the third moment is a moment next to the fourth moment; S22: Determine whether the second state parameter of the battery pack at the third moment and the second state parameter of the battery pack at the fourth moment meet a third preset condition; if so, proceed to step S23; if not, repeat steps S21 to S22; S23: Determine whether the second state parameter of the battery pack at the third moment and the second state parameter of the battery pack at the fourth moment meet a fourth preset condition; if so, proceed to step S24; if not, repeat steps S21 to S22; S24: disconnecting the charging and discharging circuits of all the cells in the battery pack, spraying fire-fighting agents to the battery pack through a fire-fighting pipeline, and releasing inert gas into the interior of the container until the oxygen concentration inside the container is lower than a preset concentration.

3. The fire control method according to claim 2, characterized in that: The third preset condition includes satisfying the following conditions at the same time: in, For the third moment, is the gas pressure inside the battery pack at the third moment, is the combustible gas concentration inside the battery pack at the third moment, For the fourth moment, is the gas pressure inside the battery pack at the fourth moment, is the combustible gas concentration inside the battery pack at the fourth moment, is the preset air pressure change rate, To preset the rate of change of the combustible gas concentration; The fourth preset condition includes satisfying at least one of the following conditions: in, To preset the maximum air pressure, It is the preset maximum combustible gas concentration.

4. The fire control method according to claim 1, characterized in that: In step S3, the first operating state of the battery pack is obtained. When the first operating state meets the heat spread condition, a three-level fire protection strategy is executed, which specifically includes: The first state parameters of all the battery cells in the battery pack are obtained respectively; when the first state parameters of two adjacent battery cells both meet the battery cell thermal runaway condition, the first operating state meets the heat spread condition, and the liquid cooling mechanism cools the battery cluster to which the battery pack belongs.

5. The fire control method according to claim 1, characterized in that: In step S4, the second operating state of the container to which the battery pack belongs is obtained. When the second operating state meets the heat diffusion condition, the fourth-level fire fighting strategy is executed, which specifically includes: The fire information inside the container is obtained. When a flame appears in the container, the second operating state satisfies the heat diffusion condition. The nozzle sprays the fire extinguishing agent to the battery cluster to extinguish the flame. When the nozzle finishes spraying the fire extinguishing agent and the flame is not extinguished, the water filling mechanism fills water into the box body of the energy storage box.

6. A fire control system of an energy storage box, the energy storage box comprising a container and a plurality of battery clusters arranged in the container, the battery cluster comprising a plurality of battery packs, the battery pack comprising a plurality of battery cells, characterized in that: The fire control system is used to execute the fire control method described in any one of claims 1 to 5, including a first-level fire module for performing fire control on the battery cell, a second-level fire module for performing fire control on the battery pack, a third-level fire module for performing fire control on the battery cluster, and a fourth-level fire module for performing fire control on the container.

7. The fire control system according to claim 6, characterized in that: The first-level fire protection module includes a deformation detector, a temperature detector and a voltage detector. The deformation detector is arranged on the explosion-proof valve of the battery cell, and the temperature detector and the voltage detector are respectively arranged on two electrode columns of the battery cell.

8. The fire control system according to claim 6, characterized in that: The secondary fire protection module includes an air pressure sensor, a combustible gas sensor, a fire protection pipe, an inert gas injection pipe and an oxygen concentration detection device. The air pressure sensor and the combustible gas sensor are both arranged in the battery pack. The container is provided with a pressure relief port. The oxygen concentration detection device is arranged in the pressure relief port. The fire protection pipe is arranged in the container. The battery pack is provided with a connecting port. The fire protection pipe is connected to the connecting port.

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