Battery thermal runaway early warning device and method based on explosion-proof valve monitoring

Abstract

The application provides a battery thermal runaway early warning device and method based on an explosion-proof valve monitoring, and belongs to the technical field of energy storage battery safety. The device comprises: a pressure detection module for detecting the pressure value at the explosion-proof valve of a target battery; a sound recognition module for detecting the volume at the explosion-proof valve of the target battery; a gas detection module for detecting the gas concentration value released by the explosion-proof valve of the target battery; and an early warning module for monitoring whether the first abnormal signal, the second abnormal signal and the third abnormal signal exist, and determining that the explosion-proof valve has been opened when at least two of the first abnormal signal, the second abnormal signal and the third abnormal signal are monitored, and outputting a thermal runaway early warning signal of the target battery. The application realizes early warning of battery runaway, improves the early warning accuracy and reduces the false positive rate, and improves the safety of the energy storage battery system.

Description

Technical Field

[0001] This application belongs to the field of energy storage battery safety technology, specifically relating to a battery thermal runaway early warning device and method based on explosion-proof valve monitoring. Background Technology

[0002] With the goal of carbon neutrality being set, electrochemical energy storage, as a key technology for power system transformation, has experienced rapid development in recent years. In particular, lithium iron phosphate (LFP) batteries, with their advantages of large capacity, low cost, and long cycle life, have gradually become the mainstream in electrochemical energy storage. However, the safety of large-capacity LFP batteries has become a significant issue for energy storage power station applications. The continuous increase in single-cell capacity exacerbates the risk of thermal runaway, posing a safety hazard to energy storage systems. Therefore, exploring the thermal runaway characteristics of large-capacity LFP batteries is of great importance in providing design guidance for battery management systems and fire protection systems used in large-scale energy storage applications.

[0003] Currently, most energy storage power station battery management systems adopt a three-tier architecture: a battery pack management slave control unit, a battery cluster management master control unit, and a battery stack management master control unit. The battery management system monitors all individual cells by collecting voltage, current, and temperature data. Existing fire suppression measures mostly involve extinguishing fires after they start and activating the fire suppression system only after thermal runaway occurs, resulting in relatively simplistic fire suppression measures. This management method lacks detailed analysis of the characteristic parameters of battery thermal runaway, especially the detection of deformation pressure, sound, and gas before thermal runaway occurs. This leads to inaccurate thermal runaway early warning functions, resulting in high false alarm rates and delays. Summary of the Invention

[0004] Based on the above technical problems, this application proposes a battery thermal runaway early warning device and method based on explosion-proof valve monitoring. By simultaneously detecting the deformation pressure, sound and gas before the occurrence of battery thermal runaway, the device can provide early warning of battery runaway, thereby improving the accuracy of the warning and reducing the false alarm rate.

[0005] In a first aspect, this application proposes a battery thermal runaway early warning device based on explosion-proof valve monitoring, comprising:

[0006] The pressure detection module is used to detect the pressure value at the explosion-proof valve of the target battery, and outputs a first abnormal signal when the pressure value is detected to be within a preset pressure value range;

[0007] A sound recognition module is used to detect the volume at the explosion-proof valve of the target battery, and output a second abnormal signal when the volume is detected to be within a preset volume range;

[0008] The gas detection module is used to detect the gas concentration value released by the explosion-proof valve of the target battery, and outputs a third abnormal signal when the increase in the gas concentration value exceeds the increase in the preset gas concentration value.

[0009] The early warning module is used to monitor whether the first abnormal signal, the second abnormal signal, and the third abnormal signal exist, and when at least two of the first abnormal signal, the second abnormal signal, and the third abnormal signal are detected, it determines that the explosion-proof valve has been opened and outputs a thermal runaway early warning signal for the target battery.

[0010] The early warning module is also used to output an abnormal early warning signal for the target battery when any one of the first abnormal signal, the second abnormal signal, or the third abnormal signal is detected.

[0011] The early warning module is also used to send the thermal runaway early warning signal to the battery management system and the fire protection system, so that the target battery stops charging or discharging, and the fire protection system is activated to cool down the target battery.

[0012] The pressure detection module includes a pressure acquisition unit and a first data processing unit;

[0013] The pressure acquisition unit is a flexible thin-film pressure sensor, which is attached to the explosion-proof valve to acquire the pressure value at the explosion-proof valve.

[0014] The first data processing unit is at a first set distance from the target battery and is used to receive the pressure value at the explosion-proof valve. If the pressure value at the explosion-proof valve is within the preset pressure value range, it is determined that the pressure at the explosion-proof valve is abnormal and a first abnormal signal is output.

[0015] The sound recognition module includes: a sound acquisition unit, a sound storage unit, and a second data processing unit;

[0016] The sound acquisition unit is used to acquire sound segments at the explosion-proof valve in real time;

[0017] The sound storage unit is used to save the collected sound segments in chronological order of acquisition time.

[0018] The second data processing unit is used to extract the volume of the saved sound segment, and if the volume is within a preset volume range, it outputs a second abnormal signal.

[0019] The second data processing unit is also used to extract features from the saved sound segments, input the features into a pre-trained sound recognition model to obtain a sound recognition result, and output a second abnormal signal if the sound recognition result is an abnormal result.

[0020] The gas detection module includes a gas detection unit disposed on the outer casing of the target battery. It is used to output a third abnormal signal when the increase in the concentration value of the gas released by the explosion-proof valve exceeds the increase in the preset gas concentration value. The increase in the concentration value is the difference between the concentration value at the current acquisition time and the concentration value at the previous acquisition time. The gas released by the explosion-proof valve includes at least one of carbon monoxide, hydrogen, methane and acetylene.

[0021] The gas detection module also includes an audible and visual alarm unit, which is used to issue an audible and visual alarm upon receiving a third abnormal signal.

[0022] The preset pressure range is 0.3 MPa to 1.2 MPa; the preset volume range is 30 dB to 100 dB; and the preset gas concentration increase is 0.02%.

[0023] Secondly, this application proposes a battery thermal runaway early warning method based on explosion-proof valve monitoring, including:

[0024] The pressure value at the explosion-proof valve of the target battery is detected, and a first abnormal signal is output when the pressure value is detected to be within a preset pressure value range;

[0025] The volume at the explosion-proof valve of the target battery is detected, and a second abnormal signal is output when the volume is detected to be within a preset volume range;

[0026] The gas concentration value released by the explosion-proof valve of the target battery is detected, and a third abnormal signal is output when the increase in the gas concentration value exceeds the increase in the preset gas concentration value.

[0027] The system monitors for the presence of the first, second, and third abnormal signals. When at least two of the first, second, and third abnormal signals are detected, it determines that the explosion-proof valve has been opened and outputs a thermal runaway warning signal for the target battery.

[0028] Beneficial effects:

[0029] This application proposes a battery thermal runaway early warning device and method based on explosion-proof valve monitoring. By simultaneously detecting the deformation pressure, sound, and gas before the occurrence of battery thermal runaway, it provides early warning of battery runaway, improves the accuracy of early warning and reduces the false alarm rate, thereby improving the safety of energy storage battery systems. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the battery thermal runaway early warning device based on explosion-proof valve monitoring according to an embodiment of this application;

[0031] Figure 2This is a schematic diagram of a flexible thin-film pressure sensor according to an embodiment of this application;

[0032] Figure 3 This is a schematic diagram of the installation of the flexible thin-film pressure sensor according to an embodiment of this application;

[0033] Figure 4 This is a schematic diagram illustrating the linkage between the battery management system and the fire protection system in an embodiment of this application.

[0034] Figure 5 This is a schematic diagram illustrating the interaction between the battery internals, the battery management system, and the fire protection system in an embodiment of this application.

[0035] Figure 6 This is a flowchart of a battery thermal runaway early warning method based on explosion-proof valve monitoring, according to an embodiment of this application.

[0036] Among them, 1-positive electrode post, 2-negative electrode post, 3-explosion-proof valve, and 4-flexible thin-film pressure sensor. Detailed Implementation

[0037] The present disclosure will be further described below with reference to the embodiments shown in the accompanying drawings.

[0038] Currently, battery management systems (BMS) monitor voltage, current, and temperature data to detect battery thermal runaway. However, this method suffers from drawbacks such as high false alarm rates and delays due to inaccurate sampling precision and mismatches between algorithms and data. Furthermore, this approach lacks detailed analysis of the characteristic parameters of battery thermal runaway, resulting in inaccurate thermal runaway early warning systems. Most existing battery fire suppression measures only address the issue after a fire has started.

[0039] Research on the characteristic parameters of battery explosion-proof valve opening and detailed analysis of the characteristic parameters of thermal runaway in individual cells reveal that the opening of the explosion-proof valve generates a violent sound, pressure release, and trace amounts of flammable gas. Furthermore, the time between the opening of the explosion-proof valve and thermal runaway is generally more than 20 minutes. This application incorporates a sound recognition module, a pressure detection module, and a gas detection module to perform sound detection, pressure monitoring, and gas detection at the explosion-proof valve, enabling linkage with the battery management system and fire suppression system to provide early warning of thermal runaway.

[0040] Example 1:

[0041] This embodiment proposes a battery thermal runaway early warning device based on explosion-proof valve monitoring, such as... Figure 1 As shown, it includes: a pressure detection module, a sound recognition module, a gas detection module, and an early warning module;

[0042] The pressure detection module, sound recognition module, and gas detection module are respectively connected to the early warning module.

[0043] The pressure detection module is used to detect the pressure value at the explosion-proof valve of the target battery, and outputs a first abnormal signal when the pressure value is detected to be within a preset pressure value range;

[0044] In this embodiment, the pressure detection module includes a pressure acquisition unit and a first data processing unit; the pressure acquisition unit is a flexible thin-film pressure sensor, such as... Figure 2 As shown, the flexible thin-film pressure sensor is attached to the explosion-proof valve to collect the pressure value at the explosion-proof valve. Figure 3 As shown, the target battery has a positive terminal 1 and a negative terminal 2. An explosion-proof valve 3 is positioned between the positive terminal 1 and the negative terminal 2. A flexible thin-film pressure sensor 4 is attached to the explosion-proof valve 3. In this embodiment, the shape of the data acquisition end of the flexible thin-film pressure sensor 4 is not limited; it can be elongated, circular, rhomboid, or needle-shaped. The flexible thin-film pressure sensor 4 is encapsulated inside the target battery. To process the data accurately and stably, the first data processing unit should be located away from the target battery. Therefore, the distance between the first data processing unit and the target battery is set to a first predetermined value. This unit receives the pressure value at the explosion-proof valve. If the pressure value at the explosion-proof valve is within the preset pressure range, an abnormal pressure is determined at the explosion-proof valve, and a first abnormal signal is output.

[0045] A sound recognition module is used to detect the volume at the explosion-proof valve of the target battery, and output a second abnormal signal when the volume is detected to be within a preset volume range;

[0046] In this embodiment, since the explosion-proof valve produces a loud noise when it opens, the volume at the explosion-proof valve of the target battery is used as the criterion for judgment. The sound recognition module can be installed at any location in the target battery according to the actual situation. Its main function is to collect the abnormal sound at the moment the explosion-proof valve of the target cell opens. Since most energy storage power stations are located in remote, uninhabited areas with little environmental noise interference, the sound recognition module can simply judge based on the volume of the sound. At this time, the sound recognition module includes at least: a sound acquisition unit, a sound storage unit, and a second data processing unit; the sound acquisition unit is used to collect sound segments at the explosion-proof valve in real time; the sound storage unit is used to save the collected sound segments in the order of acquisition time; the second data processing unit is used to extract the volume of the saved sound segments, and if the volume is within a preset volume range, a second abnormal signal is output.

[0047] In other embodiments, when the sound is relatively noisy and the sound source is not singular, the sound recognition module can also perform sound recognition and comparison to determine whether the explosion-proof valve is open or not. In this case, the sound recognition module includes at least: a sound acquisition unit, a sound storage unit, and a second data processing unit. The second data processing unit is used to extract features from the saved sound segments, input the features into a pre-trained sound recognition model, and obtain a sound recognition result. If the sound recognition result is an abnormal result, a second abnormal signal is output. The pre-trained sound recognition model can use historical data and be pre-trained using methods such as principal component analysis and neural network algorithms. The features of the sound segments are projected onto the sound recognition model, and the resulting mapping is the sound recognition result. If the sound recognition result is a certain value, then if the data exceeds a preset range, the sound recognition result is an abnormal result. If the sound recognition result is a category, then if the category belongs to an abnormal category, the sound recognition result is an abnormal result, and a second abnormal signal needs to be output.

[0048] The gas detection module is used to detect the gas concentration value released by the explosion-proof valve of the target battery, and outputs a third abnormal signal when the increase in the gas concentration value exceeds the increase in the preset gas concentration value.

[0049] In this embodiment, the gas detection module includes a gas detection unit disposed on the outer casing of the target battery. This unit outputs a third abnormal signal when the increase in the concentration of gas released from the explosion-proof valve exceeds a preset increase in gas concentration. The increase in concentration is the difference between the concentration at the current sampling time and the concentration at the previous sampling time. The gas released from the explosion-proof valve includes at least one of carbon monoxide, hydrogen, methane, and acetylene. In specific applications, the gas detection module can also be equipped with a separate audible and visual alarm unit to issue an audible and visual alarm signal upon receiving the third abnormal signal, indicating the alarm location, recording and saving the alarm information.

[0050] The early warning module is used to monitor whether the first abnormal signal, the second abnormal signal, and the third abnormal signal exist, and when at least two of the first abnormal signal, the second abnormal signal, and the third abnormal signal are detected, it determines that the explosion-proof valve has been opened and outputs a thermal runaway early warning signal for the target battery.

[0051] In practical applications, when the explosion-proof valve is open, at least two of the pressure detection module, sound recognition module, and gas detection module in this application will issue abnormal signals. At this point, it is determined that the explosion-proof valve is open and a thermal runaway warning needs to be issued for the target battery. At this time, there are at least 20 minutes before the thermal runaway occurs, so there is time to deal with the battery and prevent the battery explosion accident from happening.

[0052] When the early warning module only detects any one of the first abnormal signal, the second abnormal signal and the third abnormal signal, it directly outputs an abnormal early warning signal of the target battery, and it is only necessary to continue observing the battery.

[0053] In specific applications, the early warning module shall also send the thermal runaway early warning signal to the battery management system, so that the target battery stops charging or discharging. The battery management system determines whether to activate the fire protection system according to the detected temperature of the target battery. When necessary, it activates the fire protection system to cool down the target battery. Through the above method, the linkage with the battery management system and the fire protection system is realized, and the occurrence of battery explosion accidents is jointly prevented, as shown in Figure 4 , Figure 5 .

[0054] The temperature threshold of the target battery for activating the fire protection system, the preset pressure range of the pressure detection module, the preset volume range of the second sound recognition module, and the preset gas concentration value of the gas detection module are all obtained through experiments: when the explosion-proof valve is opened, the surface temperature of the target battery is between 60°C and 100°C, the preset pressure range is 0.3 MPa to 1.2 MPa; the preset volume range is 30 decibels to 100 decibels; the increment of the set concentration value of gas (at least one of carbon monoxide, hydrogen, methane and acetylene) is 0.02%.

[0055] In the battery thermal runaway early warning device based on explosion-proof valve monitoring of this embodiment, a pressure detection module is used to detect the pressure value at the explosion-proof valve of the target battery, and output a first abnormal signal when it is detected that the pressure value is within the preset pressure range; a sound recognition module is used to detect the volume at the explosion-proof valve of the target battery, and output a second abnormal signal when it is detected that the volume is within the preset volume range; a gas detection module is provided, configured to detect the gas concentration value released from the explosion-proof valve of the target battery, and output a third abnormal signal when it is detected that the increment of the gas concentration value exceeds the increment of the preset gas concentration value; finally, the early warning module monitors whether there are the first abnormal signal, the second abnormal signal and the third abnormal signal, and when at least two abnormal signals among the first abnormal signal, the second abnormal signal and the third abnormal signal are detected, it determines that the explosion-proof valve has been opened and outputs a thermal runaway early warning signal of the target battery. This embodiment adds parameter monitoring of the target battery in terms of pressure, sound and gas, improves the accuracy of thermal runaway early warning, can realize early early warning before battery thermal runaway, and improves the safety of the energy storage battery system.

[0056] Example 2:

[0057] This embodiment proposes a battery thermal runaway early warning method based on explosion-proof valve monitoring, which is implemented based on the device of the foregoing embodiment, as shown in Figure 6 , the method of this embodiment includes:

[0058] Step S1: Detect the pressure value at the explosion-proof valve of the target battery, and output a first abnormal signal when the pressure value is detected to be within the preset pressure value range;

[0059] Step S2: Detect the volume at the explosion-proof valve of the target battery, and output a second abnormal signal when the volume is detected to be within a preset volume range;

[0060] Step S3: Detect the gas concentration value released by the explosion-proof valve of the target battery, and output a third abnormal signal when the increase in the gas concentration value exceeds the preset increase in the gas concentration value.

[0061] Step S4: Monitor whether the first abnormal signal, the second abnormal signal, and the third abnormal signal exist, and when at least two of the first abnormal signal, the second abnormal signal, and the third abnormal signal are detected, determine that the explosion-proof valve has been opened and output a thermal runaway warning signal for the target battery.

[0062] Steps S1, S2, and S3 are not in any particular order.

[0063] The battery thermal runaway early warning method based on explosion-proof valve monitoring further includes: monitoring whether the first abnormal signal, the second abnormal signal, and the third abnormal signal exist, and when at least two of the first abnormal signal, the second abnormal signal, and the third abnormal signal are detected, determining that the explosion-proof valve has been opened and outputting a thermal runaway early warning signal for the target battery.

[0064] In step S2, the detection of the volume at the explosion-proof valve of the target battery, and the output of a second abnormal signal when the volume is detected to be within a preset volume range, includes:

[0065] Step S2.1: Real-time acquisition of sound segments from the explosion-proof valve;

[0066] Step S2.2: Save the collected audio segments in chronological order.

[0067] Step S2.3: Extract the volume of the saved sound segment. If the volume is within a preset volume range, output a second abnormal signal.

[0068] Step S2.3 can also be judged by the following method: extract the features of the saved sound segments, input the features into the pre-trained sound recognition model to obtain the sound recognition result, and output a second abnormal signal if the sound recognition result is an abnormal result.

[0069] This embodiment of the battery thermal runaway early warning method based on explosion-proof valve monitoring can simultaneously detect the pressure value at the explosion-proof valve of the target battery, the volume at the explosion-proof valve, and the gas concentration released by the explosion-proof valve. It also monitors the presence of a first, second, and third abnormal signal. When at least two of these abnormal signals are detected, it determines that the explosion-proof valve has opened and outputs a thermal runaway early warning signal for the target battery. This embodiment improves the accuracy of thermal runaway early warning, enabling early warning before battery thermal runaway and enhancing the safety of energy storage battery systems.

[0070] The various embodiments in this disclosure are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0071] The scope of protection of this disclosure is not limited to the embodiments described above. Obviously, those skilled in the art can make various modifications and variations to this disclosure without departing from its scope and spirit. If such modifications and variations fall within the scope of the claims of this disclosure and their equivalents, then the intent of this disclosure also includes such modifications and variations.

Claims

1. A battery thermal runaway early warning device based on explosion-proof valve monitoring, characterized in that, include: The pressure detection module is used to detect the pressure value at the explosion-proof valve of the target battery, and outputs a first abnormal signal when the pressure value is detected to be within a preset pressure value range; A sound recognition module is used to detect the volume at the explosion-proof valve of the target battery, and output a second abnormal signal when the volume is detected to be within a preset volume range; The gas detection module is used to detect the gas concentration value released by the explosion-proof valve of the target battery, and outputs a third abnormal signal when the increase in the gas concentration value exceeds the increase in the preset gas concentration value. The early warning module is used to monitor whether the first abnormal signal, the second abnormal signal, and the third abnormal signal exist, and when at least two of the first abnormal signal, the second abnormal signal, and the third abnormal signal are detected, it determines that the explosion-proof valve has been opened and outputs a thermal runaway early warning signal for the target battery.

2. The battery thermal runaway early warning device based on explosion-proof valve monitoring according to claim 1, characterized in that, The early warning module is also used to output an abnormal early warning signal for the target battery when any one of the first abnormal signal, the second abnormal signal, or the third abnormal signal is detected.

3. The battery thermal runaway early warning device based on explosion-proof valve monitoring according to claim 1, characterized in that, The early warning module is also used to send the thermal runaway early warning signal to the battery management system and the fire protection system, so that the target battery stops charging or discharging, and the fire protection system is activated to cool down the target battery.

4. The battery thermal runaway early warning device based on explosion-proof valve monitoring according to claim 1, characterized in that, The pressure detection module includes a pressure acquisition unit and a first data processing unit; The pressure acquisition unit is a flexible thin-film pressure sensor, which is attached to the explosion-proof valve to acquire the pressure value at the explosion-proof valve. The first data processing unit is at a first set distance from the target battery and is used to receive the pressure value at the explosion-proof valve. If the pressure value at the explosion-proof valve is within the preset pressure value range, it is determined that the pressure at the explosion-proof valve is abnormal and a first abnormal signal is output.

5. The battery thermal runaway early warning device based on explosion-proof valve monitoring according to claim 1, characterized in that, The sound recognition module includes: a sound acquisition unit, a sound storage unit, and a second data processing unit; The sound acquisition unit is used to acquire sound segments at the explosion-proof valve in real time; The sound storage unit is used to save the collected sound segments in chronological order of acquisition time. The second data processing unit is used to extract the volume of the saved sound segment, and if the volume is within a preset volume range, it outputs a second abnormal signal.

6. The battery thermal runaway early warning device based on explosion-proof valve monitoring according to claim 5, characterized in that, The second data processing unit is also used to extract features from the saved sound segments, input the features into a pre-trained sound recognition model to obtain a sound recognition result, and output a second abnormal signal if the sound recognition result is an abnormal result.

7. The battery thermal runaway early warning device based on explosion-proof valve monitoring according to claim 1, characterized in that, The gas detection module includes a gas detection unit disposed on the outer casing of the target battery. It is used to output a third abnormal signal when the increase in the concentration value of the gas released by the explosion-proof valve exceeds the increase in the preset gas concentration value. The increase in the concentration value is the difference between the concentration value at the current acquisition time and the concentration value at the previous acquisition time. The gas released by the explosion-proof valve includes at least one of carbon monoxide, hydrogen, methane and acetylene.

8. The battery thermal runaway early warning device based on explosion-proof valve monitoring according to claim 7, characterized in that, The gas detection module also includes an audible and visual alarm unit, which is used to issue an audible and visual alarm upon receiving a third abnormal signal.

9. The battery thermal runaway early warning device based on explosion-proof valve monitoring according to any one of claims 1-8, characterized in that, The preset pressure range is 0.3 MPa to 1.2 MPa; the preset volume range is 30 dB to 100 dB; and the preset gas concentration increase is 0.02%.

10. A battery thermal runaway early warning method based on explosion-proof valve monitoring, implemented using the battery thermal runaway early warning device based on explosion-proof valve monitoring as described in any one of claims 1-9, characterized in that, The method includes: The pressure value at the explosion-proof valve of the target battery is detected, and a first abnormal signal is output when the pressure value is detected to be within a preset pressure value range; The volume at the explosion-proof valve of the target battery is detected, and a second abnormal signal is output when the volume is detected to be within a preset volume range; The gas concentration value released by the explosion-proof valve of the target battery is detected, and a third abnormal signal is output when the increase in the gas concentration value exceeds the increase in the preset gas concentration value. The system monitors for the presence of the first, second, and third abnormal signals. When at least two of the first, second, and third abnormal signals are detected, it determines that the explosion-proof valve has been opened and outputs a thermal runaway warning signal for the target battery.

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