Fire extinguishing system and method for accurately positioning thermal runaway of container type energy storage power station

Abstract

The invention discloses a fire extinguishing system and method for accurate positioning of thermal runaway of a container type energy storage power station. The fire extinguishing system is composed of an energy storage power station, battery packs distributed in an array mode and a fire extinguishing system body. Each battery pack is provided with a ventilation safety valve and a fire extinguishing device, a hydrogen sensor array covering the whole area is arranged on the plane of the energy storage power station, the ventilation safety valves guide out hydrogen generated in the initial stage of thermal runaway, and the sensor array monitors the concentration of the whole area in real time. The industrial personal computer receives sensor data, constructs a gas concentration distribution diagram by combining pre-stored battery pack space distribution information, and displays a thermal runaway area on the display screen in real time. The positioning program analyzes a hydrogen concentration field based on gas diffusion characteristics, and after the position of a fault battery pack is accurately recognized, the industrial personal computer immediately triggers the fire extinguishing device in the corresponding pack to implement fixed-point fire extinguishing, so that an early fire extinguishing closed loop is formed. According to the system, through multi-sensor data fusion and gas distribution mapping technologies, rapid positioning and accurate suppression of a thermal runaway source are achieved, and the safety protection level of an energy storage power station is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of battery protection technology, and in particular to a fire protection system and method for accurately locating thermal runaway of a containerized energy storage power station. Background Art

[0002] At present, lithium battery energy storage has an absolute share in the new energy storage field. In order to ensure high energy density while achieving integration, modularization and rapid deployment capabilities, lithium battery energy storage basically adopts the form of containers. However, in actual applications, due to factors such as overcharging, short circuit, collision, and manufacturing defects, lithium batteries have the risk of thermal runaway. This thermal runaway will quickly spread inside the closed container and cause larger-scale thermal runaway, ultimately leading to fire and explosion accidents. Therefore, safety warning and fire protection of containerized energy storage power stations are currently hot research areas.

[0003] At present, the safety warning system of lithium battery energy storage power stations mainly monitors temperature, current and voltage, combustible gas, smoke and other out-of-control characteristic signals. When the monitoring data reaches the preset threshold, the system will send out an alarm signal and cut off the power and carry out fire fighting. This warning method has certain shortcomings: on the one hand, during the thermal runaway process of lithium batteries, when the voltage and current suddenly change and combustible gas and smoke appear in large quantities, the thermal runaway often enters the uncontrollable stage, and the battery pack is wrapped in a protective shell, and the temperature change is also difficult to be discovered in time, which causes the existing warning method to be unable to respond in time in the early stage of out-of-control, thus missing the best time to deal with it. On the other hand, with the improvement of fire fighting technology, large-scale energy storage power stations often adopt pack-level fire fighting, using aerosol or water directly injected into the battery pack, which not only tests the response speed of the warning system in terms of time, but also puts forward requirements for the positioning accuracy in space. At present, it is impossible to accurately locate by relying on these superficial characteristic signals.

[0004] In this context, gas monitoring and early warning is one of the better solutions at present. A large number of literatures show that a certain amount of combustible gas will be generated in the early stage of thermal runaway of lithium batteries. These gases are mainly hydrogen. At this time, the lithium battery has not completely thermally runaway, high temperature and flame have not appeared, and the voltage and current have not changed drastically. Therefore, the monitoring of combustible gas has the fastest response speed. In this case, in order to achieve pack-level positioning, some existing solutions use a large number of sensors to be directly installed in the energy storage pack. When a hydrogen signal appears, an early warning signal is issued. This solution also has certain disadvantages: First, this will cause a lot of costs. A large number of sensors and signal receivers will also bring a great cost burden to the product, which is often unacceptable to manufacturers; second, hydrogen energy sensors are often in electrochemical form, and the electric sparks generated by hydrogen energy sensors will become the first ignition source in thermal runaway, causing harm to the equipment; third, the sensor installed inside the pack will take up a certain amount of space. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a fire protection system and method for accurately locating thermal runaway of a containerized energy storage power station. By adopting technologies such as a waterproof and breathable membrane, a gas sensor array, and an advanced positioning algorithm, the system can achieve early warning and accurate positioning of thermal runaway of the energy storage power station without occupying the internal volume of the pack and using fewer gas sensors, thereby ensuring the safety of the energy storage equipment.

[0006] According to one aspect of the present application, a fire protection system for accurately locating thermal runaway of a containerized energy storage power station comprises an energy storage power station, a plurality of battery packs arranged in an array on the energy storage power station, and a fire protection system arranged on the energy storage power station, wherein the fire protection system comprises a breathable safety valve, a hydrogen sensor, and a fire extinguishing device, each of the battery packs is installed with a breathable safety valve and a fire extinguishing device, a plurality of hydrogen sensors are arranged in an array on the energy storage power station located on the plane where the breathable safety valve is located to form a hydrogen sensor array, the detection area of ​​the hydrogen sensor array can completely cover the entire plane of the energy storage power station, the breathable safety valve can diffuse the hydrogen generated in the early stage of thermal runaway from the inside of the battery pack, the hydrogen sensor array can detect the concentration of the diffused hydrogen, the hydrogen sensor array and the breathable safety valve constitute an early warning system, and the early warning system can monitor the hydrogen concentration in the entire plane of the energy storage power station in real time; the fire protection system also comprises The invention comprises an industrial computer arranged on the energy storage power station, the industrial computer is electrically connected to the hydrogen sensor array and the fire extinguishing device respectively, the industrial computer is equipped with a signal processing module and a positioning program, the signal processing module can receive and process the hydrogen concentration data information detected by the hydrogen sensor array, the positioning program is set based on a positioning algorithm, the positioning algorithm adopts a gas distribution field reconstruction algorithm, and through the spatial distribution information of the battery pack on the energy storage power station input in advance, the hydrogen concentration data of each position of the energy storage power station collected by the hydrogen sensor array received by the signal processing module is used to establish a gas concentration distribution map through a gas distribution mapping algorithm as an on-site gas distribution image, and the map is displayed through the display screen of the industrial computer, the industrial computer can obtain the position information of the battery pack located in the thermal runaway area of ​​the energy storage power station through the positioning program and control the fire extinguishing device in the corresponding battery pack to extinguish the fire, thereby forming an early fire extinguishing system.

[0007] Preferably, a hole is opened in the middle of the valve disc sealed inside the valve body of the breathable safety valve, and a waterproof breathable membrane is installed in the hole.

[0008] Preferably, the fire extinguishing device includes an aerosol fire extinguishing agent and a trigger device, and each battery pack is pre-installed with an aerosol fire extinguishing agent and a trigger device. When the hydrogen sensor array detects that a certain area of ​​the energy storage power station has thermal runaway, the industrial computer obtains the position information of the battery pack in the thermal runaway area of ​​the energy storage power station through its positioning program, and the industrial computer controls the trigger device in the battery pack in the thermal runaway area to trigger the corresponding aerosol fire extinguishing agent to produce a large amount of aerosol for fire extinguishing.

[0009] Preferably, the positioning algorithm uses a kernel extrapolation distribution mapping Kernel DM+V algorithm to obtain the average distribution and variance distribution of hydrogen concentration on the plane where the hydrogen sensor array is located. The specific steps of the Kernel DM+V algorithm are as follows: Step 1: Grid the calculation area and calculate the comprehensive weight distribution and the combined weighted reading distribution : ; in, is the sampling grid, is the gas concentration data on the sampling grid, Represents the sampling grid To the estimation grid Central location between The distance represents the Gaussian spatial kernel, represents the nuclear width; Step 2: Calculate the grid based on the comprehensive weight distribution Confidence , the calculation expression is as follows: ,in represents the scaling parameter; Step 3: Calculate the average concentration estimate : ; In the formula Expressed as the average of all sensor readings; Step 4: Calculate the weighted variance distribution and variance estimation distribution : ; in, Represents the distance sampling grid The nearest grid The estimated average distribution of gas concentration on Set to the mean of all variances; Step 5: Predict the leakage source through variance distribution, where the high fluctuation area with prominent variance distribution is usually found near the gas source, which can be used to determine whether it is close to the gas source, thereby determining the location of the leakage source.

[0010] Preferably, alternatives to the aerosol fire extinguishing agent include heptafluoropropane, two-fluid spray and water flooding.

[0011] A fire-fighting method for accurately locating thermal runaway of a containerized energy storage power station comprises the following steps: Step 1: Start the hydrogen sensor array to monitor the hydrogen concentration in the entire plane of the energy storage power station. The signal processing module in the industrial computer of the energy storage power station receives and processes the hydrogen concentration data detected by the hydrogen sensor array, and sets multiple hydrogen concentration thresholds, including the initial alarm hydrogen concentration, the intermediate alarm hydrogen concentration and the advanced alarm hydrogen concentration. When the hydrogen concentration exceeds the intermediate alarm hydrogen concentration, the signal processing module immediately triggers an alarm and sends an alarm message to the industrial computer, which automatically starts the positioning program. Step 2: Based on the spatial distribution information of the battery packs on the energy storage power station input in advance, the hydrogen concentration data at each location of the energy storage power station collected by the hydrogen sensor array received by the signal processing module is used to establish a gas concentration distribution map as an on-site gas distribution image through a gas distribution mapping algorithm, and the map is displayed on the display screen of the industrial computer. At the same time, the industrial computer obtains the variance distribution estimate of the hydrogen concentration through the positioning algorithm of the positioning program, finds the grid position with the largest variance estimation distribution value, and sets it as the position coordinate of the leakage point; Step 3: The industrial computer automatically activates the trigger device in the battery pack at the hydrogen leakage location according to the coordinate position of the hydrogen leakage point obtained by the positioning program, thereby triggering the corresponding aerosol fire extinguishing agent to produce a large amount of aerosol for fire extinguishing.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention monitors the change of hydrogen concentration in real time through the hydrogen sensor array, and can provide timely warning at the early stage of thermal runaway of the battery pack. Compared with the traditional monitoring method that relies on temperature and smoke, gas monitoring can identify potential safety risks at an earlier time, thereby improving the accuracy and sensitivity of the warning and providing operators with sufficient reaction time; 2. By combining hydrogen concentration signal processing and positioning algorithms, the present invention can quickly and accurately locate the location of thermal runaway batteries while installing a small number of sensors. Compared with solutions that use a large number of sensors or manual detection, this system can accurately locate the thermal runaway location in a more economical and faster response manner; 3. Through precise positioning, the present invention can quickly identify the location of the faulty battery, providing great technical support for the realization of pack-level precision firefighting. Compared with the previous firefighting method of using fire extinguishing agents such as heptafluoropropane to flood the entire container, the present invention only needs less fire extinguishing agent to flood the specific thermal runaway pack, and will not damage other battery packs, greatly reducing the economic losses caused by thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a flow chart of a fire-fighting method for accurately locating thermal runaway of a containerized energy storage power station according to one embodiment of the present application.

[0014] Figure 2 It is a schematic diagram of the installation of a fire protection system for accurately locating thermal runaway of a containerized energy storage power station according to an embodiment of the present application.

[0015] Figure 3 It is a hydrogen gas concentration distribution positioning cloud map of a fire protection system for accurately positioning thermal runaway of a containerized energy storage power station according to an embodiment of the present application. DETAILED DESCRIPTION

[0016] In order to make the contents of the present application easier to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0017] like Figure 2 As shown, the schematic diagram takes a certain type of 20-foot container-type energy storage power station as an example. The fire protection system for thermal runaway precise positioning of the container-type energy storage power station includes the energy storage power station, several battery packs arranged in an array on the energy storage power station, and the fire protection system arranged on the energy storage power station. The fire protection system includes a breathable safety valve, a hydrogen sensor, and a fire extinguishing device. Each battery pack is installed with a breathable safety valve and a fire extinguishing device. A plurality of hydrogen sensors are installed in an array on the energy storage power station on the plane where the breathable safety valve is located to form a hydrogen sensor array. Before installing the hydrogen sensor array, a two-dimensional coordinate system of the plane where the breathable safety valve on the energy storage power station is located is first established. The hydrogen sensor array is installed on the plane according to the algorithm requirements. It is required that the hydrogen sensor can cover the entire plane (within 1000 m) under the premise of ensuring the positioning accuracy. Figure 2For example, a 2*4 sensor array is used in the space, so that the position of the thermal runaway battery can be quickly and accurately located while installing a small number of sensors, and the coordinate positions of all breathable safety valves and hydrogen sensors on the plane are recorded at the same time; the breathable safety valve is composed of a valve body, a spring, a waterproof breathable membrane and other parts. The waterproof breathable membrane is a polymer material that can pass a small amount of gas while preventing water molecules from entering the battery pack. The valve body of the breathable safety valve has a hole in the middle of the valve disc sealed inside and a waterproof breathable membrane is installed in the hole, so that when the internal air pressure of the energy storage power station does not reach the opening pressure of the breathable safety valve in the early stage of thermal runaway, the hydrogen generated by the thermal runaway can leak out from the waterproof breathable membrane, so that the external hydrogen sensor can detect the hydrogen early. The setting of the hydrogen sensor array and the breathable safety valve constitutes an early warning system, which can monitor the hydrogen concentration in the entire plane of the energy storage power station in real time.

[0018] The fire protection system also includes an industrial computer arranged on the energy storage power station. The industrial computer is electrically connected to the hydrogen sensor array and the fire extinguishing device respectively. The industrial computer has a built-in signal processing module and a positioning program. The signal processing module can receive and process the hydrogen concentration data information detected by the hydrogen sensor array. The positioning program is set based on the positioning algorithm. The positioning algorithm adopts a gas distribution field reconstruction algorithm. Through the spatial distribution information of the battery pack on the energy storage power station input in advance, the hydrogen concentration data at each position of the energy storage power station collected by the hydrogen sensor array received by the signal processing module is used to establish a gas concentration distribution map through a gas distribution mapping algorithm as a field gas distribution image (such as Figure 3 As shown), and displayed on the display screen of the industrial computer, the scene data is visualized; the industrial computer can obtain the position information of the battery pack in the thermal runaway area of ​​the energy storage power station through the positioning program and control the fire extinguishing device in the corresponding battery pack to extinguish the fire, thereby forming an early fire extinguishing system. Specifically, the fire extinguishing device includes an aerosol fire extinguishing agent and a trigger device. Each battery pack is pre-installed with an aerosol fire extinguishing agent and a trigger device. When the hydrogen sensor array detects that a certain area of ​​the energy storage power station has thermal runaway, the industrial computer obtains the position information of the battery pack in the thermal runaway area of ​​the energy storage power station through its positioning program. The industrial computer controls the trigger device in the battery pack in the thermal runaway area to trigger the corresponding aerosol fire extinguishing agent to produce a large amount of aerosol for fire extinguishing, thereby suppressing the progressive deterioration of thermal runaway and buying time for the staff's next step of processing.

[0019] In one embodiment, alternatives to the aerosol fire extinguishing agent include heptafluoropropane, two-fluid spray, and water flooding.

[0020] In one embodiment, the positioning algorithm uses the kernel extrapolation distribution mapping Kernel DM+V algorithm to obtain the average distribution and variance distribution of hydrogen concentration on the plane where the hydrogen sensor array is located, combined with Figure 1 , the specific steps of Kernel DM+V algorithm are as follows: Step 1: Grid the calculation area and calculate the comprehensive weight distribution and the combined weighted reading distribution : ; in, is the sampling grid, is the gas concentration data on the sampling grid, Represents the sampling grid To the estimation grid Central location between The distance represents the Gaussian spatial kernel, represents the nuclear width; Step 2: Calculate the grid based on the comprehensive weight distribution Confidence , the calculation expression is as follows: ,in represents the scaling parameter; Step 3: Calculate the average concentration estimate : ; In the formula Expressed as the average of all sensor readings; Step 4: Calculate the weighted variance distribution and variance estimation distribution : ; in, Represents the distance sampling grid The nearest grid The estimated average distribution of gas concentration on Set to the mean of all variances; Step 5: Predict the leakage source through variance distribution, where the high fluctuation area with prominent variance distribution is usually found near the gas source, which can be used to determine whether it is close to the gas source, thereby determining the location of the leakage source.

[0021] A fire-fighting method for accurately locating thermal runaway of a containerized energy storage power station, combined with Figure 1 As shown, the following steps are included: Step 1: Start the hydrogen sensor array to monitor the hydrogen concentration in the entire plane of the energy storage power station. The signal processing module in the industrial computer of the energy storage power station receives and processes the hydrogen concentration data detected by the hydrogen sensor array, and sets multiple hydrogen concentration thresholds, including 10 ppm as the initial alarm hydrogen concentration; 50 ppm as the intermediate alarm hydrogen concentration (starting the fault location program); 100 ppm as the high-level alarm hydrogen concentration (emergency disposal). When the hydrogen concentration exceeds 50 ppm, the signal processing module immediately triggers an alarm and sends an alarm message to the industrial computer, which automatically starts the location program. Step 2: Based on the spatial distribution information of the battery packs on the energy storage power station input in advance, the hydrogen concentration data at each location of the energy storage power station collected by the hydrogen sensor array received by the signal processing module is used to establish a gas concentration distribution map as the on-site gas distribution image through the gas distribution mapping algorithm, and it is displayed on the display screen of the industrial computer. At the same time, the industrial computer obtains the variance distribution estimate of the hydrogen concentration through the positioning algorithm of the positioning program, finds the grid position with the largest variance estimation distribution value, and sets it as the position coordinate of the leakage point, such as Figure 3 As shown, the hydrogen leakage location is mainly concentrated in battery packs 20-22; Step 3: The industrial computer automatically activates the trigger device in the battery pack at the hydrogen leakage location according to the coordinate position of the hydrogen leakage point obtained by the positioning program, thereby triggering the corresponding aerosol fire extinguishing agent to produce a large amount of aerosol for fire extinguishing. Figure 3 As shown, the leakage location is determined to be battery pack No. 20-22, and the system will automatically open the fire extinguishing device of battery pack No. 19-23 to prevent the thermal runaway from further spreading.

[0022] The above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, rather than to limit them. Although the embodiments of the present application are described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solutions described in the above embodiments can still be modified, or some of the technical features can be replaced by equivalents, without departing from the spirit and scope defined by the claims of the present application.

Claims

1. A fire protection system for accurately locating thermal runaway of a containerized energy storage power station, comprising an energy storage power station, a plurality of battery packs arranged in an array on the energy storage power station, and a fire protection system arranged on the energy storage power station, characterized in that: The fire protection system includes a breathable safety valve, a hydrogen sensor and a fire extinguishing device. Each battery pack is equipped with a breathable safety valve and a fire extinguishing device. A plurality of hydrogen sensors are installed in an array on the energy storage power station located on the plane where the breathable safety valve is located to form a hydrogen sensor array. The detection area of ​​the hydrogen sensor array can completely cover the entire plane of the energy storage power station. The breathable safety valve can diffuse the hydrogen generated in the early stage of thermal runaway from the inside of the battery pack. The hydrogen sensor array can detect the concentration of the diffused hydrogen. The hydrogen sensor array and the breathable safety valve constitute an early warning system. The early warning system can monitor the hydrogen concentration in the entire plane of the energy storage power station in real time. The fire protection system also includes an industrial computer. The industrial computer is arranged on the energy storage power station. The industrial computer is electrically connected to the hydrogen sensor array and the fire extinguishing device respectively. The industrial computer can receive and process the hydrogen concentration data information detected by the hydrogen sensor array and control the fire extinguishing device in the battery pack to extinguish the fire.

2. According to claim 1, a fire protection system for accurately locating thermal runaway of a containerized energy storage power station is characterized in that: The industrial computer is built with a signal processing module and a positioning program. The signal processing module can receive and process the hydrogen concentration data information detected by the hydrogen sensor array. The positioning program is set based on a positioning algorithm. The positioning algorithm adopts a gas distribution field reconstruction algorithm. Through the spatial distribution information of the battery pack on the energy storage power station input in advance, the hydrogen concentration data at each position of the energy storage power station collected by the hydrogen sensor array received by the signal processing module is used to establish a gas concentration distribution map through a gas distribution mapping algorithm as an on-site gas distribution image, and display it through the display screen of the industrial computer. The industrial computer can obtain the position information of the battery pack located in the thermal runaway area of ​​the energy storage power station through the positioning program and control the fire extinguishing device in the corresponding battery pack to extinguish the fire, thereby forming an early fire extinguishing system.

3. According to claim 1, a fire protection system for accurately locating thermal runaway of a containerized energy storage power station is characterized in that: A hole is opened in the middle of the sealed valve flap inside the valve body of the breathable safety valve, and a waterproof breathable membrane is installed in the hole.

4. A fire protection system for accurately locating thermal runaway of a containerized energy storage power station according to claim 2, characterized in that: The fire extinguishing device includes an aerosol fire extinguishing agent and a trigger device. Each battery pack is pre-installed with an aerosol fire extinguishing agent and a trigger device. When the hydrogen sensor array detects that a certain area of ​​the energy storage power station has thermal runaway, the industrial computer obtains the position information of the battery pack in the thermal runaway area of ​​the energy storage power station through its positioning program. The industrial computer controls the trigger device in the battery pack in the thermal runaway area to trigger the corresponding aerosol fire extinguishing agent to generate a large amount of aerosol for fire extinguishing.

5. According to claim 2, a fire protection system for accurately locating thermal runaway of a containerized energy storage power station is characterized in that: The positioning algorithm uses the kernel extrapolation distribution mapping Kernel DM+V algorithm to obtain the average distribution and variance distribution of the hydrogen concentration on the plane where the hydrogen sensor array is located. The specific steps of the Kernel DM+V algorithm are as follows: Step 1: Grid the calculation area and calculate the comprehensive weight distribution and the combined weighted reading distribution : in, is the sampling grid, is the gas concentration data on the sampling grid, Represents the sampling grid To the estimation grid Central Location The distance between represents the Gaussian spatial kernel, represents the nuclear width; Step 2: Calculate the grid based on the comprehensive weight distribution Confidence , the calculation expression is as follows: ,in represents the scaling parameter; Step 3: Calculate the average concentration estimate : In the formula Expressed as the average of all sensor readings; Step 4: Calculate the weighted variance distribution and variance estimation distribution : in, Represents the distance sampling grid The nearest grid The estimated average distribution of gas concentration on Set to the mean of all variances; Step 5: Predict the leakage source through variance distribution, where the high fluctuation area with prominent variance distribution is usually found near the gas source, which can be used to determine whether it is close to the gas source, thereby determining the location of the leakage source.

6. A fire protection system for accurately locating thermal runaway of a containerized energy storage power station according to claim 4, characterized in that: Alternatives to the aerosol fire extinguishing agent include heptafluoropropane, two-fluid spray and water flooding.

7. A fire-fighting method for accurately locating thermal runaway of a containerized energy storage power station, characterized in that: The following steps are involved: Step 1: Start the hydrogen sensor array to monitor the hydrogen concentration in the entire plane of the energy storage power station. The signal processing module in the industrial computer of the energy storage power station receives and processes the hydrogen concentration data detected by the hydrogen sensor array, and sets multiple hydrogen concentration thresholds, including the initial alarm hydrogen concentration, the intermediate alarm hydrogen concentration and the advanced alarm hydrogen concentration. When the hydrogen concentration exceeds the intermediate alarm hydrogen concentration, the signal processing module immediately triggers an alarm and sends an alarm message to the industrial computer, which automatically starts the positioning program. Step 2: Based on the spatial distribution information of the battery packs on the energy storage power station input in advance, the hydrogen concentration data at each location of the energy storage power station collected by the hydrogen sensor array received by the signal processing module is used to establish a gas concentration distribution map as an on-site gas distribution image through a gas distribution mapping algorithm, and the map is displayed on the display screen of the industrial computer. At the same time, the industrial computer obtains the variance distribution estimate of the hydrogen concentration through the positioning algorithm of the positioning program, finds the grid position with the largest variance estimation distribution value, and sets it as the position coordinate of the leakage point; Step 3: The industrial computer automatically activates the trigger device in the battery pack at the hydrogen leakage location according to the coordinate position of the hydrogen leakage point obtained by the positioning program, thereby triggering the corresponding aerosol fire extinguishing agent to produce a large amount of aerosol for fire extinguishing.

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