Control method for flame retardant system of energy storage battery pack, and energy storage system

Abstract

A control method for a flame retardant system of an energy storage battery pack, comprising: for each battery module, when a fire occurs in the battery module, on the basis of sensor data provided by a sensor module corresponding to the battery module, determining the fire development stage of the battery module and, on the basis of the fire development stage, controlling the initial degree of opening of a gas release module corresponding to the battery module, so as to activate flame retardation; during the flame retardation, on the basis of the sensor data provided by the sensor module, updating the fire development stage of the battery module and, on the basis of the sensor data provided by the sensor module and the degree of opening of the gas release module, calculating a pressure relief rate of the battery module; and, if the current pressure relief rate falls outside of a target rate range corresponding to the current fire development stage, on the basis of the current sensor data, adjusting the degree of opening of the gas release module.

Description

Control method of energy storage battery pack fire extinguishing system and energy storage system

[0001] The present application claims priority to the Chinese patent application No. 202410846121.1 filed on June 27, 2024 with the China Patent Office, the whole content of the above application is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, for example, to a control method of energy storage battery pack fire extinguishing system and an energy storage system. BACKGROUND

[0003] In modern society, the application range of energy storage battery pack is increasingly wide, from electric vehicles to renewable energy storage, energy storage battery pack plays a vital role in the power system. However, with the increase of energy storage battery pack capacity and the diversification of application environment, the safety problem of energy storage battery pack becomes increasingly important. During the working process of energy storage battery pack, due to overcharge, overdischarge and short circuit, etc., it may produce overheat, and even cause fire in serious cases. Therefore, how to effectively realize the fire retardation of energy storage battery pack in fire has become a problem to be solved.

[0004] The related technologies of energy storage battery pack fire prevention mainly include the following:

[0005] Physical isolation technology: separate battery cells by physical isolation board to reduce the possibility of fire spreading, however, this method has limited isolation effect in case of fire, and cannot fundamentally solve the fire problem.

[0006] Chemical fire extinguishing technology: use fire extinguishing agent or fire retardant material to extinguish fire chemically when fire occurs, this method needs complex triggering mechanism, and there are technical difficulties in the storage and release process of fire extinguishing agent.

[0007] Thermal management system: control the temperature of energy storage battery pack by cooling liquid or radiator to prevent overheating, however, the response speed of thermal management system is limited, and it lacks intelligent control, cannot dynamically adjust the fire retardation measures according to the actual fire situation, and is difficult to quickly and effectively suppress the fire in case of sudden fire, the protection effect is poor.

[0008] Although the above technologies improve the safety of energy storage battery pack to some extent, the related fire retardation system usually adopts fixed fire retardation strategy, which cannot be adjusted in real time according to the actual working condition, is difficult to adapt to complex and changeable fire situation, and still has safety hidden danger. SUMMARY

[0009] The embodiment of the application provides a control method of a fire extinguishing system of an energy storage battery pack, the energy storage battery pack comprising: a plurality of battery modules encapsulated by a heat insulation fire extinguishing material; the fire extinguishing system comprising: a control module, a plurality of sensor modules corresponding to each of the battery modules, and a plurality of gas release modules corresponding to each of the battery modules; when the gas release module is turned on, the corresponding battery module is provided with fire extinguishing gas, and the battery module is depressurized; the control method of the fire extinguishing system of the energy storage battery pack is executed by the control module; the control method of the fire extinguishing system of the energy storage battery pack comprises:

[0010] For each of the battery modules:

[0011] When a fire occurs in the battery module, the fire development stage of the battery module is determined according to sensor data provided by the sensor module corresponding to the battery module, and the initial opening degree of the gas release module corresponding to the battery module is controlled according to the fire development stage to start fire extinguishing;

[0012] During the fire extinguishing process, the fire development stage of the battery module is updated according to sensor data provided by the sensor module, and the depressurization rate of the battery module is calculated according to the sensor data provided by the sensor module and the opening degree of the gas release module;

[0013] If the current depressurization rate is outside the target rate range corresponding to the current fire development stage, the opening degree of the gas release module is adjusted according to the current sensor data.

[0014] Optionally, the sensor module comprises a temperature sensor, a pressure sensor and a fire sensor;

[0015] According to the sensor data, the fire development stage of the battery module is determined, comprising:

[0016] If the reading of the fire sensor represents that a flame is detected, the reading of the temperature sensor is between a first temperature threshold and a second temperature threshold, and the reading of the pressure sensor exceeds a first pressure threshold, it is determined that the fire development stage of the battery module is a primary fire stage; wherein the first temperature threshold is less than the second temperature threshold;

[0017] If the reading of the fire sensor represents that a flame is detected, the reading of the temperature sensor is between the second temperature threshold and a third temperature threshold, and the reading of the pressure sensor exceeds a second pressure threshold, it is determined that the fire development stage of the battery module is a middle fire stage; wherein the second temperature threshold is less than the third temperature threshold, and the second pressure threshold is greater than or equal to the first pressure threshold;

[0018] If the reading of the fire sensor represents that a flame is detected, the reading of the temperature sensor exceeds the third temperature threshold, and the reading of the pressure sensor exceeds a third pressure threshold, it is determined that the fire development stage of the battery module is a fire serious stage; wherein the third pressure threshold is greater than or equal to the second pressure threshold.

[0019] Optionally, the gas release module comprises: a first gas release valve configured to release inert gas to the battery module when opened; a second gas release valve configured to release cooling gas to the battery module when opened; and a gas pressure relief valve configured to relieve pressure of the battery module when opened.

[0020] Controlling the opening degree of the gas release module corresponding to the battery module according to the fire development stage comprises:

[0021] If the fire development stage is the fire primary stage, the gas pressure relief valve is controlled to open at a primary pressure relief level corresponding opening degree, the first gas release valve is controlled to open at a first preset opening degree, and the second gas release valve is controlled to close.

[0022] If the fire development stage is the fire intermediate stage, the gas pressure relief valve is controlled to open at an intermediate pressure relief level corresponding opening degree, the first gas release valve is controlled to open at a second preset opening degree, and the second gas release valve is controlled to open at a third preset opening degree; wherein the intermediate pressure relief level corresponding opening degree is greater than the primary pressure relief level corresponding opening degree, and the second preset opening degree is greater than the first preset opening degree.

[0023] If the fire development stage is the fire serious stage, the gas pressure relief valve is controlled to open at a high pressure relief level corresponding opening degree, the first gas release valve is controlled to open at a fourth preset opening degree, and the second gas release valve is controlled to open at a fifth preset opening degree; wherein the high pressure relief level corresponding opening degree is greater than the intermediate pressure relief level corresponding opening degree, the fourth preset opening degree is greater than the second preset opening degree, and the fifth preset opening degree is greater than the third preset opening degree.

[0024] Optionally, the gas release module comprises: a gas pressure relief valve, at least one first gas release valve, and at least one second gas release valve; one of the first gas release valves is configured to release an inert gas to the battery module when opened; one of the second gas release valves is configured to release a cooling gas to the battery module when opened; and the gas pressure relief valve is configured to release pressure of the battery module when opened; calculating a pressure relief rate of the battery module according to the sensor data provided by the sensor module and the opening degree of the gas release module comprises:

[0025] According to the reading of the temperature sensor, the reading of the pressure sensor, the reading of the fire sensor and the opening of each first gas release valve, a release rate of inert gas is calculated;

[0026] According to the reading of the temperature sensor, the reading of the pressure sensor and the opening of each second gas release valve, a release rate of cooling gas is calculated;

[0027] According to the opening of the gas pressure relief valve, a pressure relief level adjustment coefficient is determined;

[0028] According to the release rate of the inert gas, the release rate of the cooling gas and the pressure relief level adjustment coefficient, a pressure relief rate of the battery module is calculated.

[0029] Optionally, the calculation formula of the release rate of the inert gas is:

[0030] wherein R inert represents the release rate of the inert gas; N1 represents the number of types of inert gas; T represents the reading of the temperature sensor; P represents the reading of the pressure sensor; F represents the reading of the fire sensor; C i represents the concentration of the i-th inert gas; a represents the temperature weight coefficient of the inert gas; b represents the pressure weight coefficient of the inert gas; g represents the fire reaction coefficient of the inert gas; 1≤i≤N1;

[0031] And / or, the calculation formula of the release rate of the cooling gas is as follows:

[0032] wherein R cool represents the release rate of the cooling gas; C j represents the concentration of the j-th cooling gas; N2 represents the number of types of cooling gas; T represents the reading of the temperature sensor; P represents the reading of the pressure sensor; d represents the temperature influence coefficient of the cooling gas; e represents the pressure influence coefficient of the cooling gas; 1≤j≤N2;

[0033] And / or, the calculation formula of the pressure relief level adjustment coefficient is as follows: R release (t) = (1 + log(1 + L(t)));

[0034] wherein R release represents the pressure relief level adjustment coefficient; L represents the pressure relief level corresponding to the opening of the gas pressure relief valve.

[0035] Optionally, the pressure relief rate of the battery module is the product of the release rate of the inert gas, the release rate of the cooling gas and the pressure relief level adjustment coefficient.

[0036] Optionally, adjusting the opening degree of the gas release module according to the current sensor data comprises:

[0037] if the current pressure relief rate is higher than the upper limit of the target rate range corresponding to the current fire development stage, decreasing at least one of the concentration of the at least one inert gas, the concentration of the at least one cooling gas and the pressure relief level of the gas pressure relief valve;

[0038] if the current pressure relief rate is lower than the lower limit of the target rate range corresponding to the current fire development stage, increasing at least one of the concentration of the at least one inert gas, the concentration of the at least one cooling gas and the pressure relief level of the gas pressure relief valve.

[0039] The application also provides a kind of energy storage system, comprising:

[0040] Energy storage battery pack, comprising: a plurality of battery modules encapsulated by heat insulation flame-retardant material;

[0041] Flame-retardant system, comprising: control module, a plurality of sensor modules and a plurality of gas release modules;Wherein, each of the sensor modules is arranged one-to-one corresponding to each of the battery modules;Each of the gas release modules is arranged one-to-one corresponding to each of the battery modules;The control module is connected with each of the sensor modules and each of the gas release modules respectively, and the control module is arranged to execute the control method of the energy storage battery pack flame-retardant system provided by any embodiment of the application.

[0042] Optionally, the flame-retardant system further comprises: a plurality of early warning modules arranged one-to-one corresponding to each of the battery modules;The early warning module is connected with the sensor module and the gas release module, and the early warning module is arranged to issue a warning when at least one of the sensor module and the gas release module fails.

[0043] Optionally, the flame-retardant system further comprises: a gas storage device, and each of the gas release modules is connected with the gas storage device through a gas release pipeline. BRIEF DESCRIPTION OF DRAWINGS

[0044] Fig. 1 is a flowchart of a flame-retardant strategy of a battery module provided by an embodiment of the application;

[0045] Fig. 2 is a structural schematic diagram of an energy storage system provided by an embodiment of the application. DETAILED DESCRIPTION

[0046] The terms "first", "second", and the like, as used in the description and the claims of the application and the above figures, are intended to distinguish between similar objects but not necessarily in an ordinal sense. It will be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of

[0047] The embodiments of the application provide a control method of a fire-retardant system of an energy storage battery pack, which can dynamically adjust fire-retardant measures according to sensor data, so that the fire-retardant system can maintain high fire-retardant effect in various complex situations, and ensure the safety and reliability of the energy storage battery pack. The method can be executed by a control module in the fire-retardant system. To facilitate the explanation of the control method, the structure of the energy storage system is first briefly described as follows.

[0048] Exemplarily, the energy storage system can include an energy storage battery pack and a fire extinguishing system. The energy storage battery pack can include a plurality of battery modules, each battery module is independently encapsulated by high-efficiency heat-insulating fire-retardant material, isolated from other battery modules, and forms a plurality of independently isolated battery modules, so as to ensure that when a certain battery module catches fire, the flame and high temperature cannot spread to other battery modules through the heat-insulating fire-retardant material in the physical structure. The fire extinguishing system can include a control module, a plurality of sensor modules and a plurality of gas release modules. The plurality of sensor modules are arranged one-to-one corresponding to each battery module, and the sensor module is arranged to detect the environment parameters related to the fire in the battery module, such as detecting the temperature and pressure inside the encapsulation structure of the battery module, so as to represent the current fire development stage. The plurality of gas release modules are arranged one-to-one corresponding to each battery module, and the gas release module is arranged to provide fire-retardant gas to the corresponding battery module and to release the pressure of the corresponding battery module when it is turned on, such as providing fire-retardant gas to the encapsulation structure of the corresponding battery module and releasing the pressure in the space encapsulated by the encapsulation structure of the corresponding battery module. The pressure release rate of the battery module can be used to describe the rate at which the battery module releases gas outward, which is related to the rate at which the gas release module corresponding to the battery module provides fire-retardant gas to the battery module, the pressure release level provided by the gas release module corresponding to the battery module and the environment in which the battery module is located, and is one of the key parameters of the fire extinguishing system, which can directly affect the pressure management and fire suppression effect of the system. Exemplarily, the fire-retardant gas can include at least one inert gas and / or at least one cooling gas. In the fire extinguishing system, each battery module is equipped with an independent sensor module to realize independent collection of the fire condition of each battery module; and each battery module is equipped with an independent gas release module to realize independent processing of the fire condition of each battery module. The control module is connected to each sensor module and each gas release module. For each battery module, the control module can automatically adjust the gas release form and concentration of the gas release module corresponding to the battery module and the pressure release level according to the fire development stage of the battery module, so as to realize efficient fire retardation. The control method of the energy storage battery pack fire extinguishing system is described below.

[0049] The same fire-retardant strategy can be used for each battery module. FIG. 1 is a flowchart of a fire-retardant strategy of a battery module according to an embodiment of the present application. Referring to FIG. 1, exemplarily, the fire-retardant strategy for each battery module includes:

[0050] S110, when the battery module catches fire, determining the fire development stage of the battery module according to the sensor data provided by the sensor module corresponding to the battery module, and controlling the initial opening degree of the gas release module corresponding to the battery module according to the fire development stage, and starting fire retardation.

[0051] Exemplarily, the sensor module can include multiple sensors for detecting the fire condition, such as a temperature sensor and a pressure sensor, and the like, and the sensor data can include readings of the sensors. Taking the temperature sensor as an example, it can be considered that the higher the reading of the temperature sensor, that is, the higher the temperature near the battery module, the more serious the fire development stage. When a fire occurs in the battery module, the more serious the fire development stage, the higher the initial opening degree of the gas release module can be controlled, so as to increase the release amount of the fire-retardant gas to improve the fire-retardant effect, and to increase the pressure relief level to avoid a high-temperature and high-pressure environment, and to reduce the risk of thermal runaway or explosion.

[0052] S120, updating the fire development stage of the battery module according to the sensor data provided by the sensor module during the fire-retardant process, and calculating the pressure relief rate of the battery module according to the sensor data provided by the sensor module and the opening degree of the gas release module.

[0053] Wherein, the fire condition is dynamically changing, therefore, updating the current fire development stage of the battery module in real time according to the sensor data during the fire-retardant process is beneficial to real-time grasp the fire condition, and serves as an important basis for adjusting the fire-retardant strategy. By calculating the pressure relief rate in real time, the current working state of the fire-retardant system can be known, and it can be judged in real time whether the working state of the fire-retardant system needs to be adjusted.

[0054] S130, if the current pressure relief rate is outside the target rate range corresponding to the current fire development stage, adjusting the opening degree of the gas release module according to the current sensor data.

[0055] Wherein, different fire development stages correspond to different target rate ranges, and the target rate ranges corresponding to different fire development stages can partially overlap or completely not overlap, which can be set according to actual needs. Exemplarily, the target rate ranges corresponding to different fire development stages can be obtained according to experience, according to safety requirements and battery performance requirements, or through multiple tests. During the fire-retardant process, if the pressure relief rate is too high, it can be caused by over-release of fire-retardant gas or too fast pressure relief, which is easy to cause waste and abuse of fire-retardant gas; if the pressure relief rate is too low, it can be caused by under-release of fire-retardant gas or too slow pressure relief, which is easy to make the battery module in a high-temperature and high-pressure environment, difficult to suppress the fire development, and increase the risk of thermal runaway. Therefore, by adjusting the opening degree of the gas release module in real time, the pressure relief rate at each moment can be controlled within the target rate range corresponding to the fire development stage at that moment, so as to achieve the best fire-retardant effect, ensure safety while avoiding waste of fire-retardant gas. If the current pressure relief rate is within the target rate range corresponding to the current fire development stage, the opening degree of the gas release module can be maintained unchanged.

[0056] The control method of the energy storage battery pack fireproof system provided by the embodiments of the present application divides the energy storage battery pack into a plurality of independent battery modules, each battery module is equipped with an independent packaging structure, a sensor module and a gas release module, and the fire problem in the module can be discovered and accurately processed in time. Meanwhile, the packaging structure composed of heat insulation and fireproof materials can realize fire isolation and prevent the fire from spreading to the entire energy storage battery pack, thereby improving the safety of the overall system. In the control method of the energy storage battery pack fireproof system, the current fire development stage is determined in real time according to the sensor data during the fireproof process, the pressure relief rate is calculated in real time in combination with the opening degree of the gas release module, and the opening degree of the gas release module is dynamically adjusted to make the pressure relief rate as much as possible within the target rate range corresponding to the fire development stage, which is equivalent to flexibly adjusting the fireproof strategy based on the fire development stage, thereby effectively inhibiting the spread of the fire and avoiding the waste of fireproof gas, and ensuring the best fireproof effect. In summary, the embodiments of the present application can dynamically adjust the opening degree of the gas release module according to the fire development situation, realize rapid response to the fire situation, effectively inhibit the spread of the fire, realize efficient and reliable fireproof effect, and ensure the safety of the energy storage battery pack.

[0057] On the basis of the above-mentioned embodiments, optionally, each gas release module is configured with a plurality of pressure relief levels, and in combination with the independent isolation structure of each battery module, a multi-stage interval energy storage battery pack fireproof system is formed. Real-time monitoring of the fire situation can be realized through each sensor module, the control module can rapidly respond in the early stage of fire occurrence, and flexibly cope with the fire development stage to automatically adjust the gas release form, concentration and pressure relief level, realize intelligent control, effectively inhibit the spread of the fire, and make the fireproof system have the characteristics of rapid response and efficient fireproofing.

[0058] The specific process of the control method will be exemplarily described below in combination with the specific structure of each functional module, but it is not intended to limit the present application.

[0059] In an embodiment, optionally, the sensor module includes a temperature sensor, a pressure sensor and a fire sensor. Exemplarily, the temperature sensor is configured to detect the temperature of the environment in which the battery module is located, for example, the temperature inside the packaging structure; the pressure sensor is configured to detect the pressure of the environment in which the battery module is located, for example, the pressure inside the packaging structure; and the fire sensor is configured to detect the fire situation of the battery module, for example, the fire sensor is a flame sensor configured to detect whether there is a flame inside the packaging structure to determine whether a fire has occurred in the battery module, and detect the size of the flame inside the packaging structure. The fire development stage can be divided into a primary fire stage, an intermediate fire stage and a severe fire stage. The severity of the above-mentioned three stages increases in a trend. Once the reading of the fire sensor indicates that a flame is detected, it can be determined that a fire has occurred.

[0060] Then, determining the fire development stage of the battery module according to the sensor data can specifically include:

[0061] If the reading of the fire sensor indicates that a flame is detected, the reading of the temperature sensor is between the first temperature threshold and the second temperature threshold, and the reading of the pressure sensor exceeds the first pressure threshold, it is determined that the fire development stage of the battery module is the primary stage of fire; wherein the first temperature threshold is less than the second temperature threshold.

[0062] If the reading of the fire sensor indicates that a flame is detected, the reading of the temperature sensor is between the second temperature threshold and the third temperature threshold, and the reading of the pressure sensor exceeds the second pressure threshold, it is determined that the fire development stage of the battery module is the intermediate stage of fire; wherein the second temperature threshold is less than the third temperature threshold, and the second pressure threshold is greater than or equal to the first pressure threshold.

[0063] If the reading of the fire sensor indicates that a flame is detected, the reading of the temperature sensor exceeds the third temperature threshold, and the reading of the pressure sensor exceeds the third pressure threshold, it is determined that the fire development stage of the battery module is the severe stage of fire; wherein the third pressure threshold is greater than or equal to the second pressure threshold.

[0064] Wherein, each of the above temperature thresholds and pressure thresholds can be determined according to experience or multiple tests, and the specific values are not limited here. Generally speaking, the higher the severity of the fire, the higher the temperature and pressure of the environment in which the battery module is located.

[0065] On the basis of the above embodiments, optionally, the gas release module includes: a first gas release valve configured to release inert gas to the battery module when opened; a second gas release valve configured to release cooling gas to the battery module when opened; and a gas pressure relief valve configured to relieve pressure on the battery module when opened. The control module adjusts the opening degree of the gas release module according to the sensor data, which can specifically be to adjust the opening degree of the first gas release valve and the second gas release valve in real time according to the sensor data and the fire development stage, to adjust the combined ratio of inert gas and cooling gas, and to control the pressure relief level of the gas pressure relief valve in real time, thereby optimizing the fire retardant effect. The pressure relief level can be divided into a primary pressure relief level, an intermediate pressure relief level, and a high pressure relief level; the opening degree of the gas pressure relief valve corresponding to the above three pressure relief levels increases in turn.

[0066] Accordingly, controlling the initial opening degree of the corresponding gas release module of the battery module according to the fire development stage includes:

[0067] If the fire development stage is the primary stage of fire, the gas pressure relief valve is controlled to open at the opening degree corresponding to the primary pressure relief level, the first gas release valve is controlled to open at the first preset opening degree, and the second gas release valve is controlled to be closed.

[0068] If the fire development stage is the middle stage of fire, the gas pressure relief valve is controlled to open at the opening degree corresponding to the middle pressure relief level, the first gas release valve is controlled to open at the second preset opening degree, and the second gas release valve is controlled to open at the third preset opening degree; wherein the opening degree corresponding to the middle pressure relief level is greater than the opening degree corresponding to the primary pressure relief level, and the second preset opening degree is greater than the first preset opening degree. Compared with the primary stage of fire, the opening degrees of the first gas release valve and the gas pressure relief valve are higher in the middle stage of fire, and cooling gas is added.

[0069] If the fire development stage is the serious stage of fire, the gas pressure relief valve is controlled to open at the opening degree corresponding to the high pressure relief level, the first gas release valve is controlled to open at the fourth preset opening degree, and the second gas release valve is controlled to open at the fifth preset opening degree; wherein the opening degree corresponding to the high pressure relief level is greater than the opening degree corresponding to the middle pressure relief level, the fourth preset opening degree is greater than the second preset opening degree, and the fifth preset opening degree is greater than the third preset opening degree. In the serious stage of fire, the gas pressure relief valve is opened at the high pressure relief level, and the opening degrees of the two gas release valves are increased, so that the combined fire-retardant gas is released with full force, ensuring that the internal pressure and temperature of the battery module packaging structure can be rapidly reduced.

[0070] On the basis of the above-mentioned embodiments, optionally, in one gas release module, the number of first gas release valves is at least one, and when the number of first gas release valves is multiple, different kinds of inert gases can be respectively connected; the number of second gas release valves is at least one, and when the number of second gas release valves is multiple, different kinds of cooling gases can be respectively connected.

[0071] The pressure relief rate of the battery module is calculated according to the sensor data provided by the sensor module and the opening degree of the gas release module, which can specifically include:

[0072] The release rate of the inert gas is calculated according to the reading of the temperature sensor, the reading of the pressure sensor, the reading of the fire sensor and the opening degree of each first gas release valve.

[0073] The release rate of the cooling gas is calculated according to the reading of the temperature sensor, the reading of the pressure sensor and the opening degree of each second gas release valve.

[0074] The pressure relief level adjustment coefficient is determined according to the opening degree of the gas pressure relief valve.

[0075] The pressure relief rate of the battery module is calculated according to the release rate of the inert gas, the release rate of the cooling gas and the pressure relief level adjustment coefficient.

[0076] Exemplarily, the pressure relief rate of the battery module is the product of the release rate of the inert gas, the release rate of the cooling gas and the pressure relief level adjustment coefficient. The calculation formula of the pressure relief rate is as follows: R(t) = Rinert (t) · R cool (t) · R release (t) ;

[0077] wherein R represents the rate of pressure relief, R inert represents the rate of inert gas release, R cool represents the rate of cooling gas release, R release represents the pressure relief level adjustment coefficient. The parameters with "(t)" represent that the parameter varies with time, for example, R(t) can represent the rate of pressure relief at time t, and the other parameters are the same, and will not be repeated.

[0078] Exemplarily, the calculation formula of the rate of inert gas release is as follows:

[0079] wherein N1 represents the number of types of inert gas; T represents the reading of the temperature sensor; P represents the reading of the pressure sensor; F represents the reading of the fire sensor; C i represents the concentration of the i-th inert gas; a represents the temperature weight coefficient of the inert gas; b represents the pressure weight coefficient of the inert gas; g represents the fire reaction coefficient of the inert gas; 1≤i≤N1. The reading F of the fire sensor is for example between 0-1, 0 represents no fire, and 1 represents fire. It can be understood that the concentration of the inert gas refers to the concentration of the inert gas applied to the battery module packaging structure, which can be set according to the fire development level, and which can be used as a basis for setting the opening degree of the first gas release valve. At the beginning of the fire, the initial concentration can be set to determine the initial opening degree of the first gas release valve. During the fire retardation process, the concentration value can be adjusted for calculation, and the opening degree of the first gas release valve can be adjusted according to the final calculation result.

[0080] The formula combines the comprehensive effects of temperature, pressure and fire, and the calculation result based on the formula can dynamically adjust the release rate of the inert gas. The application of the exponential function and the sine function makes the release rate more sensitive and complex to the changes of the sensor data.

[0081] The calculation formula of the rate of cooling gas release is as follows:

[0082] wherein C jrepresents the concentration of the jth cooling gas; N2 represents the number of types of cooling gas; δ represents the cooling gas temperature influence coefficient; ∈ represents the cooling gas pressure influence coefficient; 1≤j≤N2. It can be understood that the concentration of the cooling gas refers to the concentration of the cooling gas applied to the battery module packaging structure, which can be set according to the fire development level, and which can be used as a basis for setting the opening degree of the second gas release valve. At the beginning of the fire, an initial concentration can be set to determine the initial opening degree of the second gas release valve. During the fire retardation process, the concentration value can be adjusted for calculation, and the opening degree of the second gas release valve can be adjusted according to the final calculation result.

[0083] The formula ensures that the release of the cooling gas meets the actual needs by integrating the temperature and the pressure and combining the cooling gas concentration; and the use of the square root and the cosine function makes the part of the formula more complex and nonlinear in response to data.

[0084] The calculation formula of the pressure relief level adjustment coefficient is as follows: R release (t)=(1+log(1+L(t)));

[0085] Wherein, L represents the pressure relief level corresponding to the opening degree of the gas pressure relief valve. The numerical range of the primary pressure relief level is, for example, 0-1, the numerical range of the intermediate pressure relief level is, for example, 1-2, and the numerical range of the high-level pressure relief level is, for example, between 2-3. The use of the logarithmic function to adjust the pressure relief level makes the adjustment of the pressure relief level smoother and has a larger dynamic range.

[0086] Wherein, the value range of R(t) represents the pressure relief rate calculated according to the readings of multiple sensors at a specific time point; the larger the value, the more the combined gas released, and the faster the pressure relief, so as to respond to the current fire condition.

[0087] Through the calculation of the release rates of the inert gas and the cooling gas and the pressure relief level adjustment coefficient, the influence of the changes of the sensor data and the different fire stages on the gas release demand can be accurately reflected. It can be determined whether the current gas release behavior of the battery module belongs to normal, insufficient or abuse, so as to dynamically adjust at least one of the concentrations of various fire-retardant gases, the readings of the fire sensors and the pressure relief level in real time, so as to optimize the pressure relief rate, improve the safety and stability of the system, and reduce the risk of fire and explosion.

[0088] On the basis of the above-mentioned embodiments, the opening degree of the gas release module is adjusted according to the current sensor data, which can specifically include:

[0089] If the current pressure relief rate is higher than the upper limit of the target rate range corresponding to the current fire development stage, at least one of the concentration of at least one inert gas, the concentration of at least one cooling gas, the pressure relief level of the gas pressure relief valve and the reading of the fire sensor is reduced.

[0090] If the current depressurization rate is lower than the lower limit of the target rate range corresponding to the current fire development stage, at least one of the following is increased: the concentration of at least one inert gas, the concentration of at least one cooling gas, the depressurization level of the gas depressurization valve, and the reading of the fire sensor.

[0091] After adjustment, R(t) can be calculated again. If R(t) is still outside the target rate range, adjustment can be made again. Through continuous iteration adjustment by feedback loop, until the calculated value of R(t) reaches the target rate range, accurate control of the multi-stage interval energy storage battery pack fire suppression system can be achieved. The opening of the first gas release valve is adjusted based on the release rate calculation result of the inert gas, the opening of the second gas release valve is adjusted based on the release rate calculation result of the cooling gas, and the opening of the gas depressurization valve is adjusted based on the depressurization level, so as to optimize the depressurization rate, keep the real-time depressurization rate of multi-stage depressurization stable, and improve the safety and stability of the system.

[0092] The embodiments of the present application provide an efficient and intelligent fire suppression system control method, which is particularly suitable for application scenarios that require high safety and real-time monitoring, and specific uses include but are not limited to the following energy storage systems:

[0093] Electric vehicles: Provide protection for energy storage battery packs of electric vehicles to prevent fire accidents caused by overheating, overcharging, or short circuit, etc.

[0094] Renewable energy storage: Applied to energy storage systems of renewable energy such as wind and solar energy, to ensure the safe operation of energy storage battery packs under high load and complex environment.

[0095] Data center backup power: Used in backup power systems of data centers to ensure the safe and stable operation of energy storage battery packs during power anomalies.

[0096] Industrial equipment: Provides a safe energy storage solution for large industrial equipment to prevent damage to equipment and personnel caused by energy storage battery pack fires.

[0097] Residential and commercial buildings: Applied to energy storage systems in residential and commercial buildings to improve fire safety and protect life and property safety.

[0098] The embodiments of the present application adopt real-time sensor data acquisition, which can monitor the temperature, pressure and fire situation of the energy storage battery pack (for energy storage battery pack applications that require high precision monitoring, such as electric vehicles and data center backup power supplies), and transmit the data to the control module for processing. Through the preset complex formula, the release rate of inert gas and cooling gas and the pressure relief level adjustment coefficient are dynamically calculated. This real-time data processing and analysis method enables the fire retardant system to respond quickly and accurately according to the actual situation, avoiding the problem of fire spread caused by delayed response in related technologies. In actual application, according to the calculation result, the fire retardant system can intelligently and dynamically adjust the pressure relief level, thereby controlling the release rate of gas; this intelligent control method enables the system to provide appropriate pressure relief rate and fire retardant gas release rate according to the different needs of the fire development stage, ensuring the best fire retardant effect at each stage.

[0099] In order to verify the effect of the control method, the applicant provides the following experiment, and the experimental steps are as follows:

[0100] Step one, system initialization: initialize each sensor, each gas release valve and gas pressure relief valve, and the control module; ensure that the temperature sensor, pressure sensor and fire sensor are installed in the packaging structure of each independent battery module; configure the gas storage device, including high-pressure tanks for storing inert gas (such as nitrogen) and cooling gas (such as liquid nitrogen); connect the control module to ensure that the sensor data is transmitted to the control module in real time; set the initial concentration of inert gas C i (t) and cooling gas C j (t), the initial concentration of each type of fire-retardant gas can be set according to the fire development stage.

[0101] Step two: start the energy storage battery pack, simulate the working state, and record the changes of temperature and pressure. The initial temperature is set to 300K, and the initial pressure is set to 100kPa.

[0102] Step three, sensor data acquisition; real-time acquisition of temperature sensor reading T(t), pressure sensor reading P(t) and gas concentration C i (t) and C j (t) data, and transmit the data to the control module, so that the control module calculates the pressure relief rate R(t) in real time through the formula.

[0103] Step four: according to the real-time calculation of R(t), dynamically adjust at least one of C i (t), C j (t), F(t) and L(t) to ensure that the pressure relief rate is within a safe range.

[0104] In the above experiment, the specific experimental data is shown in Table 1, taking three kinds of inert gas and cooling gas as an example, the gas concentration unit is %, and the gas release rate unit is L / s.

[0105] Table 1

[0106] In the above experiment, the change of the pressure relief rate is:

[0107] In the initial stage, the pressure relief rate R(0) is 0.0948, and as time goes on, the increase of temperature and pressure leads to the gradual increase of R(t). The release rate R inert (t) of the inert gas and the release rate R release (t) of the cooling gas show a gradually increasing trend over time, which indicates that the system can inhibit the combustion reaction by releasing more inert gas and cooling gas when facing increasing temperature and pressure. Especially at high temperature and high pressure, by increasing the concentration of cooling gas, the temperature of the battery module can be effectively reduced to prevent thermal runaway.

[0108] Wherein, the adjustment of the variable L(t) directly affects R release (t), by appropriately increasing L(t), the pressure relief rate can be effectively increased to ensure the stability of the system. Adjusting C i (t) can change the oscillation amplitude of the release rate of the inert gas. For example, when the system temperature or pressure is too high, increasing the value of at least one C i (t) helps to increase the release rate of the inert gas, thereby inhibiting the severity of the reaction.

[0109] Through the above data analysis, it is shown that the control method provided by the embodiments of the application can effectively manage the release ratio and rate of the inert gas and the cooling gas, quickly suppress temperature rise, dynamically adjust the fire retardant measures according to the fire development stage and real-time sensor data, and ensure the safety and reliability of the energy storage battery pack. The related art can only set fixed parameters and cannot adjust in real time according to the actual fire situation, and the dynamic response mechanism of the application solves this problem, so that the fire retardant system can maintain high fire retardant effect under various complex conditions.

[0110] The embodiments of the application also provide an energy storage system, which can apply the control method of the energy storage battery pack fire retardant system provided by any of the embodiments of the application, and has the corresponding beneficial effects. FIG. 2 is a structural schematic diagram of an energy storage system provided by an embodiment of the application. Referring to FIG. 2, the energy storage system can include an energy storage battery pack 100 and a fire retardant system 200.

[0111] The energy storage battery pack 100 can include a plurality of battery modules 11, each of which is packaged by a packaging structure 12, and the packaging structure 12 can be made of a heat-insulating and fire-retardant material. The fire-retardant system 200 can include a control module 21, a plurality of sensor modules 22, and a plurality of gas release modules 23. Each sensor module 22 is arranged in one-to-one correspondence with each battery module 11, each gas release module 23 is arranged in one-to-one correspondence with each battery module 11, and the control module 21 is connected to each sensor module 22 and gas release module 23, and the control module 21 is arranged to execute a control method of the energy storage battery pack fire-retardant system.

[0112] The sensor module 22 can include a temperature sensor arranged to detect the temperature of the environment in which the battery module 11 is located, for example, the temperature inside the packaging structure 12, a pressure sensor arranged to detect the pressure of the environment in which the battery module 11 is located, for example, the pressure inside the packaging structure 12, and a fire sensor arranged to detect the fire condition of the battery module 11, for example, to detect whether there is a flame inside the packaging structure 12 to determine whether the battery module 11 has caught fire, and to detect the size of the flame inside the packaging structure 12. The detection part of each type of sensor can be arranged inside the packaging structure 12 to detect the relevant conditions of the battery module 11.

[0113] The gas release module 23 can include a plurality of gas release valves arranged to release a plurality of fire-retardant gases to the battery module 11 when opened. The gas release valve, for example, includes a first gas release valve arranged to release an inert gas to the battery module 11 when opened, for example, arranged on the packaging structure 12 to release the inert gas into the packaging structure 12 when opened, and a second gas release valve arranged to release a cooling gas to the battery module 11 when opened, for example, arranged on the packaging structure 12 to release the cooling gas into the packaging structure 12 when opened. The gas release module 23 also includes a gas pressure relief valve arranged to release the pressure of the battery module 11 when opened, for example, arranged on the packaging structure 12 to release the pressure inside the space defined by the packaging structure 12 when opened. The opening degree of the gas release module 23 is controlled by the control module 21. The opening degree of the gas release module 23 can include the opening degree of each gas release valve and the opening degree of the gas pressure relief valve.

[0114] It should be noted that FIG. 2 mainly uses block diagram structure and connection lines to represent the corresponding relationship of each functional module in the energy storage system, and does not represent the actual position relationship of each functional module. In actual application, the position relationship of each functional module in the fire-retardant system 200 and the battery module 11 can be configured according to the needs, which is not limited here.

[0115] The energy storage system provided by the embodiments of the present application divides the energy storage battery pack 100 into a plurality of independent battery modules 11, each battery module 11 is equipped with an independent packaging structure 12, a sensor module 22 and a gas release module 23, and the fire problem in the module can be found and accurately handled in time. At the same time, the packaging structure 12 composed of heat insulation and flame retardant materials can realize fire isolation and prevent the fire from spreading to the entire energy storage battery pack 100, thereby improving the safety of the overall system. Moreover, during the fire retardation process, the control module 21 determines the current fire development stage according to the sensor data of the sensor module 22 in real time, dynamically calculates the pressure relief rate of the battery module 11 in real time, and adjusts the opening degree of the gas release module 23 to make the pressure relief rate as much as possible within the target rate range corresponding to the fire development stage, so as to realize flexible adjustment of the fire retardation strategy based on the fire development stage, thereby effectively inhibiting the spread of the fire, avoiding the waste of fire retardant gas, and ensuring the best fire retardation effect.

[0116] On the basis of the above-mentioned embodiments, the fire retardation system 200 further includes a gas storage device, specifically a gas release valve in each gas release module 23, which is connected to the gas storage device through a gas release pipeline. The gas storage device can store fire retardant gas, so that when the gas release valve is opened, the fire retardant gas is released to the battery module 11 through the gas release pipeline. For example, the gas storage device can include at least one inert gas storage component, and one inert gas storage component is connected to the corresponding first gas release valve in each gas release module 23. When there are a plurality of inert gas storage components, different inert gas storage components are used to store different kinds of inert gas, and different inert gas storage components are connected to different first gas release valves in the same gas release module 23. The gas storage device can also include at least one cooling gas storage component, and one cooling gas storage component is connected to the corresponding second gas release valve in each gas release module 23. When there are a plurality of cooling gas storage components, different cooling gas storage components are used to store different kinds of cooling gas, and different cooling gas storage components are connected to different second gas release valves in the same gas release module 23.

[0117] On the basis of each of the above embodiments, optionally, the fire-retardant system 200 can further comprise: a plurality of early warning modules, each corresponding to a battery module 11; the early warning module is connected to the sensor module 22 and the gas release module 23, and is configured to detect whether the working state of the sensor module 22 and the gas release module 23 is abnormal, and to issue a warning when at least one of the sensor module 22 and the gas release module 23 fails, so as to ensure that relevant personnel are notified in time to handle the fire. Illustratively, a backup fire-retardant system can be configured in the energy storage system, and when the early warning module corresponding to any battery module 11 issues a warning, the functional module corresponding to the battery module 11 in the backup fire-retardant system can be enabled to ensure that the fire can be stopped and extinguished, and the safety of the energy storage system is ensured. Illustratively, the early warning module can also be connected to the control module 21 and report the fault module and the fault type to the control module 21 when issuing a warning, so as to facilitate relevant personnel to handle in time.

[0118] On the basis of each of the above embodiments, optionally, the control module 21 can comprise a data acquisition unit, a central processing unit (CPU) unit and a real-time judgment unit. The data acquisition unit is configured to acquire sensor data to monitor the temperature change and pressure condition of the environment where the battery module 11 is located in real time, and to monitor whether a fire occurs; the CPU unit is configured to receive and analyze the sensor data to determine the fire development stage; and the real-time judgment unit is configured to determine whether the combined gas needs to be released according to the fire development stage, and if so, to adjust the real-time pressure relief rate of the system according to the sensor data, and the influence coefficient of the pressure relief rate includes the release rate of the inert gas, the release rate of the cooling gas and the pressure relief level adjustment coefficient.

[0119] It should be understood that various forms of the flow shown above can be used to reorder, add or delete steps. For example, each step described in the present application can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, and the present application does not limit here.

Claims

1. A control method for a flame-retardant system of an energy storage battery pack, the energy storage battery pack comprising: Multiple battery modules encapsulated with heat-insulating and flame-retardant materials; The flame-retardant system includes: a control module, multiple sensor modules corresponding to each of the battery modules, and multiple gas release modules corresponding to each of the battery modules; when the gas release module is activated, it provides flame-retardant gas to the corresponding battery module and depressurizes the battery module; the control method of the flame-retardant system of the energy storage battery pack is executed by the control module; the control method of the flame-retardant system of the energy storage battery pack includes: For each of the battery modules: When a fire occurs in the battery module, the fire development stage of the battery module is determined based on the sensor data provided by the sensor module corresponding to the battery module, and the initial opening degree of the gas release module corresponding to the battery module is controlled according to the fire development stage to start flame retardancy. During the flame retardant process, the fire development stage of the battery module is updated based on the sensor data provided by the sensor module, and the depressurization rate of the battery module is calculated based on the sensor data provided by the sensor module and the opening degree of the gas release module. If the current pressure relief rate is outside the target rate range corresponding to the current stage of fire development, the opening degree of the gas release module is adjusted according to the current sensor data.

2. The control method for the flame-retardant system of the energy storage battery pack according to claim 1, wherein, The sensor module includes: a temperature sensor, a pressure sensor, and a fire sensor; Determining the fire development stage of the battery module based on the sensor data includes: If the reading of the fire sensor indicates that a flame has been detected, the reading of the temperature sensor is between a first temperature threshold and a second temperature threshold, and the reading of the pressure sensor exceeds a first pressure threshold, then the fire development stage of the battery module is determined to be the initial stage of the fire; wherein, the first temperature threshold is less than the second temperature threshold. If the reading of the fire sensor indicates that a flame has been detected, the reading of the temperature sensor is between the second temperature threshold and the third temperature threshold, and the reading of the pressure sensor exceeds the second pressure threshold, then the fire development stage of the battery module is determined to be the intermediate stage of the fire; wherein, the second temperature threshold is less than the third temperature threshold, and the second pressure threshold is greater than or equal to the first pressure threshold. If the reading of the fire sensor indicates that a flame has been detected, the reading of the temperature sensor exceeds the third temperature threshold, and the reading of the pressure sensor exceeds the third pressure threshold, then the fire development stage of the battery module is determined to be a severe fire stage; wherein the third pressure threshold is greater than or equal to the second pressure threshold.

3. The control method for the flame-retardant system of the energy storage battery pack according to claim 2, wherein, The gas release module includes: a first gas release valve configured to release inert gas to the battery module when opened; a second gas release valve configured to release cooling gas to the battery module when opened; and a gas pressure relief valve configured to relieve pressure on the battery module when opened. Controlling the initial activation level of the gas release module corresponding to the battery module according to the fire development stage includes: If the fire development stage is the initial stage of the fire, then the gas pressure relief valve is controlled to open at the opening degree corresponding to the initial pressure relief level, the first gas release valve is controlled to open at the first preset opening degree, and the second gas release valve is controlled to close. If the fire development stage is the intermediate stage, then the gas pressure relief valve is controlled to open at the opening degree corresponding to the intermediate pressure relief level, the first gas release valve is controlled to open at the second preset opening degree, and the second gas release valve is controlled to open at the third preset opening degree; wherein, the opening degree corresponding to the intermediate pressure relief level is greater than the opening degree corresponding to the primary pressure relief level, and the second preset opening degree is greater than the first preset opening degree. If the fire development stage is the severe stage of the fire, then the gas pressure relief valve is controlled to open at the opening degree corresponding to the high pressure relief level, the first gas release valve is controlled to open at the fourth preset opening degree, and the second gas release valve is controlled to open at the fifth preset opening degree; wherein, the opening degree corresponding to the high pressure relief level is greater than the opening degree corresponding to the intermediate pressure relief level, the fourth preset opening degree is greater than the second preset opening degree, and the fifth preset opening degree is greater than the third preset opening degree.

4. The control method for the flame-retardant system of the energy storage battery pack according to claim 2, wherein, The gas release module includes: a gas pressure relief valve, at least one first gas release valve, and at least one second gas release valve; one of the first gas release valves is configured to release an inert gas to the battery module when open; one of the second gas release valves is configured to release a cooling gas to the battery module when open; the gas pressure relief valve is configured to release the pressure of the battery module when open; the pressure relief rate of the battery module is calculated based on sensor data provided by the sensor module and the degree of opening of the gas release module, including: The release rate of inert gas is calculated based on the readings of the temperature sensor, the pressure sensor, the fire sensor, and the opening degree of each of the first gas release valves. The release rate of cooling gas is calculated based on the readings of the temperature sensor, the pressure sensor, and the opening degree of each of the second gas release valves. The pressure relief level adjustment coefficient is determined based on the opening degree of the gas pressure relief valve; The pressure relief rate of the battery module is calculated based on the release rate of the inert gas, the release rate of the cooling gas, and the pressure relief level adjustment coefficient.

5. The control method for the flame-retardant system of the energy storage battery pack according to claim 4, wherein, The formula for calculating the release rate of the inert gas is: Among them, R inert N represents the release rate of the inert gas; N1 represents the number of inert gas types; T represents the temperature sensor reading; P represents the pressure sensor reading; F represents the fire sensor reading; C i The concentration of the i-th inert gas is represented by α; the inert gas temperature weighting coefficient is represented by β; the inert gas pressure weighting coefficient is represented by γ; and the inert gas fire response coefficient is represented by 1 ≤ i ≤ N1. And / or, the formula for calculating the release rate of the cooling gas is as follows: Among them, R cool Indicates the release rate of the cooling gas; C j Nj represents the concentration of the j-th cooling gas; N2 represents the number of cooling gas types; T represents the temperature sensor reading; P represents the pressure sensor reading; δ represents the cooling gas temperature influence coefficient; ε represents the cooling gas pressure influence coefficient; 1≤j≤N2; And / or, the formula for calculating the pressure relief level adjustment coefficient is as follows: R release (t)=(1+log(1+L(t))); Among them, R release This indicates the pressure relief level adjustment coefficient; L represents the pressure relief level corresponding to the opening degree of the gas pressure relief valve.

6. The control method for the flame-retardant system of the energy storage battery pack according to claim 4, wherein, The depressurization rate of the battery module is the product of the release rate of the inert gas, the release rate of the cooling gas, and the depressurization level adjustment coefficient.

7. The control method for the flame-retardant system of the energy storage battery pack according to claim 4, wherein, Adjusting the activation level of the gas release module based on current sensor data includes: If the current pressure relief rate is higher than the upper limit of the target rate range corresponding to the current fire development stage, then reduce the concentration of at least one inert gas, reduce the concentration of at least one cooling gas, and reduce the pressure relief level of the gas pressure relief valve by at least one of the following: If the current pressure relief rate is lower than the lower limit of the target rate range corresponding to the current fire development stage, then increase the concentration of at least one inert gas, increase the concentration of at least one cooling gas, and increase the pressure relief level of the gas pressure relief valve by at least one of the following:

8. An energy storage system, comprising: Energy storage battery pack, including: multiple battery modules encapsulated with heat-insulating and flame-retardant materials; A flame-retardant system includes: a control module, multiple sensor modules, and multiple gas release modules; wherein each sensor module is configured to correspond one-to-one with each battery module; each gas release module is configured to correspond one-to-one with each battery module; the control module is connected to each sensor module and each gas release module respectively, and the control module is configured to execute the control method of the flame-retardant system for the energy storage battery pack according to any one of claims 1-7.

9. The energy storage system according to claim 8, further comprising: Multiple warning modules are configured to correspond one-to-one with each of the battery modules; the warning module is connected to the sensor module and the gas release module, and the warning module is configured to issue a warning when at least one of the sensor module and the gas release module malfunctions.

10. The energy storage system according to claim 8, wherein, The flame-retardant system also includes a gas storage device, and each of the gas release modules is connected to the gas storage device through a gas release pipeline.

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