Device and method for testing fire extinguishing and cooling efficiency of lithium battery fire extinguishing agent in limited space

Abstract

The invention discloses an experimental device and an experimental method for testing fire extinguishing and cooling efficiency of a lithium battery fire extinguishing agent in a limited space in the field of fire extinguishing agent performance research. The experimental device comprises a conveying pipeline, a fire extinguishing bottle, a cooling bottle, a test box, a heating device, a smoke detector, a fire alarm controller, a temperature acquisition device, a pressure sensor, a camera system and a data acquisition system. The data acquisition system controls the fire alarm controller to close the fire extinguishing bottle and starts the cooling bottle to spray a corresponding fire extinguishing agent to the lithium battery after the fire extinguishing bottle sprays and when the conveying pressure is zero, the fire extinguishing time used for fire extinguishing is calculated, and the surface temperature of the lithium battery after the cooling bottle sprays and when the conveying pressure is zero is also acquired. The experimental device can be used for exploring the fire extinguishing effect and the cooling effect of the fire extinguishing agent respectively, experimental support is provided for evaluating the lithium battery fire extinguishing efficiency of the fire extinguishing agent in a limited space, and therefore the fire extinguishing agent capable of meeting the efficient fire extinguishing and cooling requirements of lithium battery fire disasters can be researched and developed early.

Description

Technical Field

[0001] The present invention relates to a fire extinguishing agent effectiveness experimental device and an experimental method in the field of fire extinguishing agent performance research, and in particular to an experimental device and an experimental method for testing the fire extinguishing and cooling effectiveness of a fire extinguishing agent for a confined space lithium battery, and a design method for an optimal fire extinguishing agent for a confined space lithium battery obtained by using the experimental device and the experimental method. Background Art

[0002] With the development of high-tech, lithium battery energy storage technology has gradually matured, and lithium batteries have been widely used in the energy sector. The widespread use of lithium batteries increases the risk of battery fires. During battery use, they may be affected by environmental or human factors, such as overcharging, heat, and puncture, which can cause thermal runaway and fire. If not controlled in a timely manner, this can trigger thermal runaway in other batteries, causing serious economic losses. An efficient fire extinguishing system is an effective way to suppress and interrupt the spread of lithium battery fires. The key factor affecting the fire extinguishing system's ability to quickly suppress lithium battery fires lies in the effectiveness of the fire extinguishing agent.

[0003] Currently, no fire extinguishing agent can fully meet the requirements for efficient fire extinguishing and cooling of lithium battery fires. Researchers are still continuously researching and developing fire extinguishing agents that are fully suitable for lithium battery fires. Effectively evaluating the fire extinguishing effectiveness of fire extinguishing agents on lithium battery fires is a key step in fire extinguishing agent research and development. However, evaluating the fire extinguishing effectiveness and cooling effect of fire extinguishing agents on lithium battery fires is difficult, which is not conducive to the development of lithium battery fire extinguishing agents. Efficient fire extinguishing agent performance evaluation devices can promote the development of fire extinguishing agents. Summary of the Invention

[0004] In order to provide motivation and experimental support for the early development of a fire extinguishing agent that can fully meet the needs of efficient fire extinguishing and cooling of lithium battery fires, the present invention provides an experimental device and experimental method for testing the fire extinguishing and cooling efficiency of fire extinguishing agents for lithium batteries in confined spaces, and a design method for the optimal fire extinguishing agent for lithium batteries in confined spaces obtained using the experimental device and the experimental method.

[0005] The present invention is implemented by the following technical solution: an experimental device for testing the fire extinguishing and cooling efficiency of a lithium battery fire extinguishing agent in a confined space, comprising: Delivery pipeline; Fire extinguishing bottles and cooling bottles used to contain fire extinguishing agents of the same configuration, with a known amount of fire extinguishing agents, and to release the fire extinguishing agents through the delivery pipeline; Test chamber for loading lithium batteries; A heating device that heats lithium batteries until thermal runaway occurs before disconnecting the power supply; Smoke detectors that detect changes in smoke concentration within the test chamber and send out smoke alarm signals when smoke concentration exceeds the limit; Fire alarm controller that activates fire extinguisher bottle to spray fire extinguishing agent to lithium battery according to smoke alarm signal; A temperature collection device for collecting the surface temperature of the lithium battery; A pressure sensor for detecting the fire extinguishing agent delivery pressure in the delivery pipeline; A camera system that photographs lithium batteries to identify the time of fire onset and extinguishment of the lithium batteries; The data acquisition system controls the fire alarm controller to shut down the fire extinguisher bottle and simultaneously starts the cooling bottle to spray the corresponding fire extinguishing agent onto the lithium battery after the fire extinguisher bottle is sprayed and the delivery pressure is zero. The data acquisition system also calculates the time difference between the start-up time of the fire extinguisher bottle and the fire extinguishing time as the fire extinguishing time used for fire extinguishing. The surface temperature of the lithium battery is also collected after the cooling bottle is sprayed and the delivery pressure is zero.

[0006] As a further improvement of the above solution, the experimental device further includes: two solenoid valves for respectively controlling the ejection and release of the fire extinguishing agent in the fire extinguishing bottle and the cooling bottle through the delivery pipeline.

[0007] As a further improvement of the above solution, the experimental device further includes: a pipeline pressure sensor for monitoring the pressure change of the fire extinguishing agent in the delivery pipeline, and the data acquisition system collects monitoring data of the pipeline pressure sensor.

[0008] As a further improvement of the above solution, the experimental device further includes: a pipeline temperature sensor for monitoring temperature changes of the fire extinguishing agent transported in the transport pipeline, and the data acquisition system collects monitoring data of the pipeline temperature sensor.

[0009] As a further improvement of the above solution, the experimental device further includes: a flue gas analyzer for extracting gas from the test box to perform component analysis, and the data acquisition system collects analysis data from the flue gas analyzer.

[0010] As a further improvement of the above scheme, both the fire extinguishing bottle and the cooling bottle are installed with a filling assembly, which includes two manual ball valves, two three-way joints, and a four-way joint, each part of which is connected into a whole through a pipe; the four-way joint is respectively connected to the fire extinguishing bottle or the cooling bottle and the two three-way joints, and the remaining passage forms a third interface for filling liquid or powder fire extinguishing agent into the fire extinguishing bottle or the cooling bottle; the two three-way joints are respectively connected to the two manual ball valves, and form a first interface and a fifth interface respectively, the first interface is used to fill gas and gas fire extinguishing agent into the fire extinguishing bottle or the cooling bottle, and the fifth interface is used to adjust the pressure in the fire extinguishing bottle or the cooling bottle; the remaining passages of the two three-way joints form a second interface and a fourth interface respectively.

[0011] As a further improvement to the above solution, the delivery pipeline is connected to the center just above the test box through three consecutive 90° elbows at the end of the delivery pipeline, and the fire extinguishing agent is sprayed onto the lithium batteries in the test box through the top plate of the test box.

[0012] Furthermore, the delivery pipeline is fixed at the center of the top plate of the test box through a through-plate joint, the through-plate joint is connected to the delivery pipeline, and the end is connected to a porous nozzle for diffuse spraying of the fire extinguishing agent.

[0013] As a further improvement of the above solution, the heating device includes a heating plate and a clamp, and the clamp fastens the heating plate and the lithium battery adjacent to each other.

[0014] The present invention also provides a method for testing the fire extinguishing and cooling efficiency of a lithium battery fire extinguishing agent in a confined space, which is applied to any of the above-mentioned experimental devices for testing the fire extinguishing and cooling efficiency of a lithium battery fire extinguishing agent in a confined space. The experimental method comprises the following steps: S11. Load a lithium battery into the test chamber, and respectively load a fire extinguishing agent of the same configuration with a known filling amount m of fire extinguishing agent into the fire extinguishing bottle and the cooling bottle; S12, after heating the lithium battery to thermal runaway, disconnecting the power supply of the heating device; S13, detect the change of smoke concentration in the test chamber and send out a smoke alarm signal when the smoke concentration exceeds the limit; S14, controlling the fire extinguisher bottle to spray the fire extinguishing agent onto the lithium battery according to the smoke alarm signal; S15, detecting the delivery pressure of the fire extinguishing agent in the delivery pipeline; S16, photographing the lithium battery and identifying the time of fire onset and fire extinguishing of the lithium battery; S17. After the fire extinguisher bottle is sprayed and the delivery pressure is zero, the fire extinguisher bottle is controlled to be closed and the cooling bottle is activated to spray the corresponding fire extinguishing agent onto the lithium battery. The time difference between the activation time of the fire extinguisher bottle and the fire extinguishing time is calculated as the fire extinguishing time t used for fire extinguishing. The surface temperature T of the lithium battery is also collected after the cooling bottle is sprayed and the delivery pressure is zero; Repeat steps S11 to S17 to conduct experiments using the experimental device for fire extinguishing agents with the same filling volume but different types, or the same filling volume but different configurations, and record the filling volume m, fire extinguishing time t, and surface temperature T of the lithium battery in each test.

[0015] The present invention also provides a method for designing an optimal fire extinguishing agent for lithium batteries in confined spaces, which comprises the following steps: S21. Load a lithium battery into the test chamber, and respectively load a fire extinguishing agent of the same configuration with a known filling amount m of fire extinguishing agent into the fire extinguishing bottle and the cooling bottle; S22, heating the lithium battery until thermal runaway occurs and then stopping heating; S23, detect the change of smoke concentration in the test chamber and send out a smoke alarm signal when the smoke concentration exceeds the limit; S24, controlling the fire extinguisher bottle to spray the fire extinguishing agent onto the lithium battery according to the smoke alarm signal; S25, detecting the delivery pressure of the fire extinguishing agent ejected from the fire extinguishing bottle; S26. Photographing the lithium battery to identify the time of fire onset and the time of fire extinguishment of the lithium battery; S27. After the fire extinguisher bottle is sprayed and the delivery pressure is zero, the fire extinguisher bottle is controlled to be closed and the cooling bottle is activated to spray the corresponding fire extinguishing agent onto the lithium battery. The time difference between the activation time of the fire extinguisher bottle and the fire extinguishing time is calculated as the fire extinguishing time t used for fire extinguishing. The surface temperature T of the lithium battery is also collected after the cooling bottle is sprayed and the delivery pressure is zero; Repeat steps S21 to S27 to conduct separate experiments with different types of fire extinguishing agents with the same filling volume, or different configurations with the same filling volume. Record the filling volume m, fire extinguishing time t, and lithium battery surface temperature T for each test. S28. The fire extinguishing agent with the minimum filling amount m, fire extinguishing time t, and surface temperature T of the lithium battery is selected as the optimal fire extinguishing agent.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention has built an experimental device for testing the fire extinguishing and cooling efficiency of lithium battery fire extinguishing agents in confined spaces. The experimental device can measure the temperature and pressure in the fire extinguishing bottle, cooling bottle, and fire extinguishing agent pipeline in real time during the experimental test, and can also collect and analyze the smoke composition and lithium battery temperature changes in the test box; the device can realize the fire extinguishing spray and cooling spray functions of the fire extinguishing agent, and can be used to explore the fire extinguishing and cooling effects of the fire extinguishing agent respectively, providing experimental support for evaluating the effectiveness of the fire extinguishing agent in extinguishing lithium battery fires in confined spaces, so that a fire extinguishing agent that can fully meet the needs of efficient fire extinguishing and cooling of lithium battery fires can be developed as soon as possible.

[0017] 2. The present invention provides an experimental method for testing the fire extinguishing and cooling efficiency of lithium battery fires in confined spaces. Based on the experimental device and combined with this method, the detection, response, fire extinguishing and cooling of lithium battery fires in confined spaces can be realized. By comparing the fire extinguishing agent filling amount, fire extinguishing time and cooling rate, the most efficient fire extinguishing agent for extinguishing lithium battery fires can be screened out, which provides method support for evaluating the effectiveness of fire extinguishing agents in extinguishing lithium battery fires in confined spaces and improves the rate of screening the effectiveness of fire extinguishing agents.

[0018] 3. The present invention also provides a method for designing an optimal fire extinguishing agent for lithium batteries in confined spaces. Based on the experimental device and experimental method of the present invention, many research and development ideas can be proposed, and the fire extinguishing and cooling effects of different fire extinguishing agents on lithium battery fires can be compared, and the best fire extinguishing agent for extinguishing lithium battery fires can be selected, providing a reference for lithium battery fire protection in the energy storage field. This solves the problem in the existing technology that it is difficult to evaluate the fire extinguishing effectiveness and cooling effect of fire extinguishing agents on lithium battery fires, which is not conducive to the development of lithium battery fire extinguishing agents. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of an experimental device for testing the fire extinguishing and cooling efficiency of a lithium battery fire extinguishing agent in a confined space provided by an embodiment of the present invention.

[0020] Figure 2 for Figure 1 Schematic diagram of the structure of the fire extinguisher bottle and its fire extinguisher bottle filling assembly in the experimental device.

[0021] Figure 3 for Figure 1 Schematic diagram of the main structure of the experimental device.

[0022] Figure 4 for Figure 1 Schematic diagram of the detection, fire extinguishing and cooling response connections of the experimental device.

[0023] Figure 5 for Figure 1 Schematic diagram of the data acquisition system connection of the experimental device.

[0024] Figure 6 for Figure 1 Schematic diagram of the experimental method flow chart of the experimental setup.

[0025] Figure 7 for Figure 1 Schematic diagram of the specific practical experimental steps of the experimental device.

[0026] Figure 8 Based on Figure 7 Temperature change diagram of the lithium battery surface after executing the experimental steps in .

[0027] Figure 9 A schematic flow chart of a method for designing an optimal fire extinguishing agent for lithium batteries in confined spaces provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] Example 1 See also Figure 1 , which is a schematic diagram of the structure of an experimental apparatus for testing the fire extinguishing and cooling effectiveness of a lithium battery fire extinguishing agent in a confined space, provided by an embodiment of the present invention. This experimental apparatus is used to test the fire extinguishing and cooling effectiveness of a fire extinguishing agent on a lithium battery fire within a confined space. The experimental apparatus of the present invention is intended to effectively evaluate the fire extinguishing effectiveness of a fire extinguishing agent on lithium battery fires, namely, to evaluate the fire extinguishing effectiveness and cooling effect of the fire extinguishing agent on lithium battery fires, thereby promoting the research and development of fire extinguishing agents, and ultimately, developing a fire extinguishing agent that is fully suitable for lithium battery fires and can fully meet the requirements for efficient fire extinguishing and cooling of lithium battery fires.

[0030] The experimental device includes a fire extinguisher bottle filling assembly 1, a cooling bottle filling assembly 2, a fire extinguisher bottle 3, a cooling bottle 4, a cooling solenoid valve 5, a fire extinguishing solenoid valve 6, a fixing bracket 7, a conveying pipeline 8, a pipeline pressure sensor 9, a pipeline temperature sensor 10, a test box 11, a nozzle 12, a lithium battery heating device 13, a temperature acquisition device 14, a data acquisition system 15, a flue gas analyzer 16, a smoke detector 17, a fire alarm controller 18 and a camera system 19.

[0031] The fixing bracket 7 is used to secure the fire extinguisher bottle 3, the cooling bottle 4, the cooling solenoid valve 5, and the fire extinguisher solenoid valve 6. The fixing bracket 7 is constructed of aluminum profiles, which can be connected together using angle fittings, screws, and bolts. Universal wheels can also be mounted on the bottom of the fixing bracket 7 to facilitate its movement and transport. In this embodiment, four universal wheels are mounted on the bottom of the fixing bracket 7 via threaded connections. The fire extinguisher bottle filling assembly 1 and the cooling bottle filling assembly 2 are installed on the fire extinguisher bottle 3 and the cooling bottle 4 respectively. The fire extinguisher bottle filling assembly 1 and the cooling bottle filling assembly 2 have the same structure. Figure 2 The fire extinguisher bottle filling assembly 1 and the cooling bottle filling assembly 2 can both include two manual ball valves 1-6, a pressure sensor (not shown), two three-way connectors 1-7, a four-way connector 1-8, and a temperature sensor (not shown). Each component is connected to form a whole through stainless steel pipes and fixed to the fire extinguisher bottle 3 and the cooling bottle 4 through straight connectors. Taking the fire extinguisher bottle 3 as an example, the connection is explained in detail: the four-way connector 1-8 is connected to the fire extinguisher bottle 3 and the two three-way connectors 1-7 respectively, and the remaining passage forms the third interface 1-3, which is used to fill the fire extinguisher bottle 3 with high-boiling point, liquid, or powder fire extinguishing agents; the two three-way connectors 1-7 are connected to the two manual ball valves 1-6 respectively, and form the first interface 1-1 and the fifth interface 1-5 respectively. The first interface 1-1 is used to fill the fire extinguisher bottle 3 with gas and gas fire extinguishing agent, and the fifth interface 1-5 is used to adjust the pressure in the fire extinguisher bottle 3; the remaining passages of the two three-way connectors 1-7 form the second interface 1-2 and the fourth interface 1-4 respectively, both of which can be used for backup.

[0032] Please combine Figure 3The fire extinguisher bottle 3 is used to release the fire extinguishing agent for extinguishing the lithium battery fire, and the cooling bottle 4 is used to release the fire extinguishing agent for cooling the lithium battery. The fire extinguisher bottle and the cooling bottle are respectively used to contain the fire extinguishing agent of the same configuration, and the filling amount of the fire extinguishing agent is known. Then the fire extinguishing agent can be sprayed and released through the delivery pipeline. Of course, different delivery pipelines can also be used for spraying and releasing. The fire extinguisher bottle 3 and the cooling bottle 4 can be stainless steel cylinders. The fire extinguisher bottle 3 and the cooling bottle 4 can be fixed to the fixed frame 7 by a pipe clamp structure with the same diameter as the cylinder. The outlet of the fire extinguisher bottle 3 and the cooling bottle 4 can be connected to a stainless steel pipe with a ferrule through a 90° elbow. The end of the stainless steel pipe can be connected to the fire extinguishing solenoid valve 6 and the cooling solenoid valve 5 through a ferrule joint.

[0033] Please combine Figure 4 The cooling solenoid valve 5 and the fire extinguishing solenoid valve 6 are controlled by the fire alarm controller 18. The fire extinguishing solenoid valve 6 is used to control the release of the fire extinguishing agent in the fire extinguishing bottle 3, and the cooling solenoid valve 5 is used to control the release of the coolant in the cooling bottle 4. The outlet ends of the fire extinguishing solenoid valve 6 and the cooling solenoid valve 5 are connected to stainless steel pipes with ferrules, the ends of which are connected to 90° elbows and converge into the same stainless steel delivery pipeline 8 through a tee joint.

[0034] Two four-way joints can be installed on the delivery pipeline 8. One side of the four-way joints is a compression fitting, and the other side is an NPT internal thread. A pipeline pressure sensor 9 and a pipeline temperature sensor 10 can be symmetrically installed at the NPT internal thread joints. In this embodiment, the fire extinguishing solenoid valve 6 and the cooling solenoid valve 5 respectively control the release of fire extinguishing agent from the fire extinguishing bottle 3 and the cooling bottle 4. The pipeline pressure sensor 9 and the pipeline temperature sensor 10 are installed on the fire extinguishing agent delivery pipeline 8 through threaded connections to monitor the temperature and pressure changes of the fire extinguishing agent within the pipeline. At the end of the fire extinguishing agent delivery pipeline 8, a stainless steel pipe can be connected to the center directly above the test chamber 11 via three consecutive 90° elbows. The stainless steel pipe is fixed to the center of the top plate of the test chamber 11 via a through-plate joint. The end of the through-plate joint is connected to a multi-hole nozzle for diffuse spraying of the fire extinguishing agent.

[0035] The test chamber 11 can be made of a stainless steel box with observation windows with explosion-proof glass on all sides. The interior of the test chamber 11 can be a cubic space, and a lithium battery heating device 13 is installed in the test chamber 11. The heating device 13 can be used to heat the lithium battery until thermal runaway occurs before disconnecting the power supply. Runaway can be based on identifying the lithium battery on fire as a standard, or it can be based on identifying the lithium battery reaching the ignition point temperature as a standard. As shown below, the camera system 19 photographs the lithium battery to identify the lithium battery on fire and fire extinguishing. The technology for identifying the onset and extinguishing of fire by image is no longer a secret. Even the image recognition of fire is now relatively mature. Therefore, the image recognition function of the camera system 19 will not be introduced here. The lithium battery heating device 13 can include a heating plate and a clamp. The clamp is connected by bolts to fasten the heating plate and lithium battery adjacent to each other, so that the heating plate can fully transfer heat to the lithium battery. In addition, the test chamber 11 can also include a temperature acquisition device 14, a flue gas analyzer sampling tube 20, and a smoke detector 17. The probe of the temperature acquisition device 14 can be arranged on the upper surface of the lithium battery and above the safety valve to collect the surface temperature and flame temperature of the lithium battery. The flue gas analyzer sampling tube 20 is installed on the top of the test box 11 through a plate-through joint to extract the gas in the test box 11. The smoke detector 17 is fixed to the top of the test box 11 by bolts to monitor the smoke changes in the test box 11. In this embodiment, the lithium battery is placed in a sealed test box 11. The test box 11 is provided with explosion-proof observation windows on all four sides for filming and observation. The lithium battery and the lithium battery heating device 13 are placed in the middle area of ​​the test box 11. The temperature acquisition device 14 is provided above and on the surface of the lithium battery to collect the temperature of the lithium battery when it thermally runs away and ignites. The nozzle 12 is installed on the wall of the test box 11 directly above the lithium battery.

[0036] Please combine Figure 5 The data acquisition system 15 can be connected to the pipeline pressure sensor 9 and the pipeline temperature sensor 10 via a cable. The thermocouple of the temperature acquisition device 14 can be a K-type thermocouple and can be arranged on the upper surface of the battery and above the battery safety valve. The K-type thermocouple transmits temperature data to the data acquisition system 15 via a 9705 module and a 24V DC power supply.

[0037] The flue gas analyzer 16 can be connected to the sampling tube installed in the test box 11 through the gas path, and transmit the CO and H2 data to the data acquisition system 15 through the data line. The flue gas analyzer 16 extracts gas from the test box 11 for analysis and transmits the analysis data to the data acquisition system 15.

[0038] The smoke detector 17 is connected to the fire alarm controller 18 via a data cable. The fire alarm controller 18 transmits data via the data cable to the data acquisition system 15. The data acquisition system 15 is also connected to the fire extinguishing solenoid valve 6 and the cooling solenoid valve 5. Therefore, the smoke detector 17 transmits smoke alarm data to the fire alarm controller 18, which in turn transmits the data to the data acquisition system 15. In response to the smoke alarm signal, the fire extinguishing solenoid valve 6 and the cooling solenoid valve 5 are activated to extinguish the fire. After the fire extinguisher bottle 3 is sprayed and the delivery pressure reaches zero, the data acquisition system 15 controls the fire alarm controller 18 to shut off the fire extinguisher bottle 3 (this can be achieved by closing the fire extinguishing solenoid valve 6) and simultaneously activate the cooling solenoid valve to spray the corresponding fire extinguishing agent (this can be achieved by opening the cooling solenoid valve 5). The data acquisition system 15 also calculates the time difference between the activation time of the fire extinguisher bottle 3 (the opening time of the fire extinguishing solenoid valve 6 can be used as the activation time) and the fire extinguishing time (the time when the camera system 19 recognizes the fire is extinguished can be used as the fire extinguishing time) as the fire extinguishing time. The data acquisition system also records the surface temperature of the lithium battery after the cooling solenoid bottle 4 sprays and the delivery pressure reaches zero.

[0039] During the experiment, the fire alarm controller 18 receives the alarm signal from the smoke detector 17, transmits the signal to the data acquisition system 15, and starts the fire extinguishing solenoid valve to spray the fire extinguishing agent. When the data acquisition system 15 detects that the coefficient of the pipeline pressure sensor 9 is 0, it starts the cooling solenoid valve 5 and sprays the cooling fire extinguishing agent to cool the battery.

[0040] Therefore, the data acquisition system 15 can collect and display in real time data such as the pipeline pressure sensor 9, the pipeline temperature sensor 10, the temperature and pressure of the fire extinguisher bottle filling assembly 1, the temperature and pressure of the cooling bottle filling assembly 2, the smoke composition of the smoke analyzer 16, and the smoke signal of the smoke detector 17.

[0041] When the experimental device of the present invention is used, the corresponding experimental method for testing the fire extinguishing and cooling efficiency of the lithium battery fire extinguishing agent in a confined space is as follows: Figure 6 The following steps are shown: S11. Load a lithium battery into the test chamber, and respectively load a fire extinguishing agent of the same configuration with a known filling amount m of fire extinguishing agent into the fire extinguishing bottle and the cooling bottle; S12, after heating the lithium battery to thermal runaway, disconnecting the power supply of the heating device; S13, detect the change of smoke concentration in the test chamber and send out a smoke alarm signal when the smoke concentration exceeds the limit; S14, controlling the fire extinguisher bottle to spray the fire extinguishing agent according to the smoke alarm signal; S15, detecting the delivery pressure of the fire extinguishing agent in the delivery pipeline; S16, photographing the lithium battery and identifying the time of fire onset and fire extinguishing of the lithium battery; S17. After the fire extinguisher bottle is sprayed and the delivery pressure is zero, the fire extinguisher bottle is controlled to be closed and the cooling bottle is activated to spray the corresponding fire extinguishing agent. The time difference between the activation time of the fire extinguisher bottle and the fire extinguishing time is calculated as the fire extinguishing time t used for fire extinguishing. The surface temperature T of the lithium battery is also collected after the cooling bottle is sprayed and the delivery pressure is zero; Repeat steps S11 to S17 to conduct experiments using the experimental device for fire extinguishing agents with the same filling volume but different types, or the same filling volume but different configurations, and record the filling volume m, fire extinguishing time t, and surface temperature T of the lithium battery in each test.

[0042] In this embodiment, when the experimental device of the present invention is used, its corresponding test method for extinguishing a lithium battery fire in a confined space and cooling efficiency is as follows: Figure 7 The following steps are shown: S1. Connect all components into a whole using machinery, circuits, and pipes, fill the fire extinguisher bottle 3 and the cooling bottle 4 with fire extinguishing agent and nitrogen respectively, and turn on the camera system 19; S2. Turn on the data acquisition system 15 to collect temperature, pressure, and smoke data of each node simultaneously, and adjust the pressure relief ball valves of the fire extinguisher bottle filling assembly 1 and the cooling bottle filling assembly 2 to a specific pressure; S3, after heating the lithium battery to thermal runaway, disconnecting the power supply of the lithium battery heating device 13; S4, the smoke detector 17 sends an alarm signal and transmits the signal to the fire alarm controller 18, the fire alarm controller 18 transmits the signal to the data acquisition system 15, and simultaneously activates the fire extinguishing solenoid valve to spray the fire extinguishing agent; S5, the data acquisition system 15 activates the cooling solenoid valve 5 by monitoring the changes in the pipeline pressure sensor 9. When the value of the pipeline pressure sensor 9 is 0, the system feeds back the signal to the fire alarm controller 18, and the fire alarm controller 18 activates the cooling solenoid valve 5 to spray the fire extinguishing agent; S6. Replace the fire extinguishing agent and repeat steps S1-S5 to compare the filling amount m of the fire extinguishing agent, the fire extinguishing time t, and the battery surface temperature T.

[0043] By using the experimental device of the present invention, many experiments can be conducted, a lot of data can be obtained, and various analyses can be performed on the data. For example, a fire extinguishing agent with minimum values ​​of m, t, and T can be selected, indicating that the fire extinguishing agent has the best fire extinguishing and cooling effect on lithium battery fires and is the optimal fire extinguishing agent.

[0044] In order to verify the effect of the present invention, the experimental device of the present invention is used, and according to Figure 7The experimental steps compared the fire extinguishing and cooling efficiency of perfluorohexanone and 2-BTP. First, the fire extinguishing agent and nitrogen were filled according to S1. The total filling amount of fire extinguishing bottle 3 and cooling bottle 4 of each fire extinguishing agent was 2.0 kg, and the filling pressure of fire extinguishing bottle 3 and cooling bottle 4 was 0.5 MPa respectively. Furthermore, the experiment was carried out according to steps S2-S6. Finally, the experimental results were analyzed according to S7. During the experiment, the fire extinguishing agent filling amount m of perfluorohexanone and 2-BTP were both 2.0 kg. The camera system analyzed the time t1=4s for perfluorohexanone to extinguish the open flame of the lithium battery, and the time t1=7s for 2-BTP to extinguish the open flame of the lithium battery. Figure 8 The surface temperature change diagram of the lithium battery is shown in Figure 2. Figure 7 The maximum surface temperature of lithium battery fire extinguished by perfluorohexanone is t2 = 490.7°C, and the maximum surface temperature of lithium battery fire extinguished by 2-BTP is t2 = 525.0°C. Therefore, it can be seen from the comparison that perfluorohexanone has a faster fire extinguishing time and better cooling effect than 2-BTP.

[0045] In summary, the data acquisition system 15 collects the temperature and pressure of the fire extinguisher bottle, cooling bottle, and pipeline, as well as the temperature and gas composition of the lithium battery flame. The fire extinguishing agent is sprayed and released through the lithium battery fire response module, which consists of an integrated smoke and temperature detector, a fire alarm controller, and a solenoid valve. Combined with the temperature and pressure data from the data acquisition system, the effects of variables such as the fire extinguishing agent filling amount, pipeline flow parameters, and fire extinguishing agent release time on lithium battery fire extinguishing can be determined. The fire extinguishing and cooling effects of different fire extinguishing agents on lithium battery fires can then be compared, and the optimal fire extinguishing agent for lithium battery fires can be selected. This provides a reference for lithium battery fire protection in the energy storage field and solves the problem in the prior art of difficulty in evaluating the fire extinguishing effectiveness and cooling effect of fire extinguishing agents on lithium battery fires, which is not conducive to the development of lithium battery fire extinguishing agents.

[0046] Example 2 According to the experimental device and experimental method of Example 1, a design method for an optimal fire extinguishing agent for lithium batteries in confined spaces can be developed. Figure 9 , the design method comprises the following steps: S21. Load a lithium battery into the test chamber, and respectively load a fire extinguishing agent of the same configuration with a known filling amount m of fire extinguishing agent into the fire extinguishing bottle and the cooling bottle; S22, heating the lithium battery until thermal runaway occurs and then stopping heating; S23, detect the change of smoke concentration in the test chamber and send out a smoke alarm signal when the smoke concentration exceeds the limit; S24, controlling the fire extinguisher bottle to spray the fire extinguishing agent onto the lithium battery according to the smoke alarm signal; S25, detecting the delivery pressure of the fire extinguishing agent ejected from the fire extinguishing bottle; S26. Photographing the lithium battery to identify the time of fire onset and the time of fire extinguishment of the lithium battery; S27. After the fire extinguisher bottle is sprayed and the delivery pressure is zero, the fire extinguisher bottle is controlled to be closed and the cooling bottle is activated to spray the corresponding fire extinguishing agent. The time difference between the activation time of the fire extinguisher bottle and the fire extinguishing time is calculated as the fire extinguishing time t used for fire extinguishing. The surface temperature T of the lithium battery is also collected after the cooling bottle is sprayed and the delivery pressure is zero; Repeat steps S21 to S27 to conduct separate experiments with different types of fire extinguishing agents with the same filling volume, or different configurations with the same filling volume. Record the filling volume m, fire extinguishing time t, and lithium battery surface temperature T for each test. S28. The fire extinguishing agent with the minimum filling amount m, fire extinguishing time t, and surface temperature T of the lithium battery is selected as the optimal fire extinguishing agent.

[0047] With the experimental device and experimental method of Example 1, the spray release of fire extinguishing agent can be achieved through the lithium battery fire response module composed of an integrated smoke and temperature detector, a fire alarm controller, and a solenoid valve. Combined with the temperature and pressure data of the data acquisition system, the influence of variables such as the fire extinguishing agent filling amount, pipeline flow parameters, and fire extinguishing agent release time on lithium battery fire extinguishing can be obtained, and the fire extinguishing and cooling effects of different fire extinguishing agents on lithium battery fires can be compared. Based on Example 1, various research and development extensions can be made. For example, the fire extinguishing agent with the minimum filling amount m, fire extinguishing time t, and lithium battery surface temperature T is selected as the optimal fire extinguishing agent, and the best fire extinguishing agent for extinguishing lithium battery fires can be selected, providing a reference for lithium battery fire protection in the energy storage field.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An experimental device for testing the fire extinguishing and cooling efficiency of lithium battery fire extinguishing agents in confined spaces, characterized in that: It includes: Delivery pipeline; Fire extinguishing bottles and cooling bottles used to contain fire extinguishing agents of the same configuration, with a known amount of fire extinguishing agents, and to release the fire extinguishing agents through the delivery pipeline; Test chamber for loading lithium batteries; A heating device that heats lithium batteries until thermal runaway occurs before disconnecting the power supply; Smoke detectors that detect changes in smoke concentration within the test chamber and send out smoke alarm signals when smoke concentration exceeds the limit; Fire alarm controller that activates fire extinguisher bottle to spray fire extinguishing agent to lithium battery according to smoke alarm signal; A temperature collection device for collecting the surface temperature of the lithium battery; A pressure sensor for detecting the fire extinguishing agent delivery pressure in the delivery pipeline; A camera system that photographs lithium batteries to identify the time of fire onset and extinguishment of the lithium batteries; The data acquisition system controls the fire alarm controller to shut down the fire extinguisher bottle and simultaneously starts the cooling bottle to spray the corresponding fire extinguishing agent onto the lithium battery after the fire extinguisher bottle is sprayed and the delivery pressure is zero. The data acquisition system also calculates the time difference between the start-up time of the fire extinguisher bottle and the fire extinguishing time as the fire extinguishing time used for fire extinguishing. The surface temperature of the lithium battery is also collected after the cooling bottle is sprayed and the delivery pressure is zero.

2. The fire extinguishing and cooling efficiency test device for testing the fire extinguishing agent for lithium batteries in confined spaces according to claim 1, characterized in that: The experimental device also includes: Two solenoid valves respectively control the release of fire extinguishing agents in the fire extinguishing bottle and the cooling bottle through the delivery pipeline.

3. The fire extinguishing and cooling efficiency test device for testing the fire extinguishing agent for lithium batteries in confined spaces according to claim 1, characterized in that: The experimental device also includes: a pipeline pressure sensor for monitoring pressure changes of the fire extinguishing agent delivered in the delivery pipeline, wherein the data acquisition system acquires monitoring data of the pipeline pressure sensor; And / or, the experimental device further comprises: A pipeline temperature sensor is used to monitor the temperature change of the fire extinguishing agent in the delivery pipeline, and the data acquisition system collects monitoring data of the pipeline temperature sensor.

4. The fire extinguishing and cooling efficiency test device for testing a fire extinguishing agent for a lithium battery in a confined space according to claim 1, characterized in that: The experimental device also includes: A flue gas analyzer is used to extract gas from the test box for component analysis, and the data acquisition system collects analysis data from the flue gas analyzer.

5. The fire extinguishing and cooling efficiency test device for testing the fire extinguishing agent for lithium batteries in confined spaces according to claim 1, characterized in that: Both the fire extinguishing bottle and the cooling bottle are installed with a filling assembly, which includes two manual ball valves, two three-way joints, and a four-way joint, each part of which is connected into a whole through pipes; the four-way joint is respectively connected to the fire extinguishing bottle or the cooling bottle and the two three-way joints, and the remaining passage forms a third interface, which is used to fill liquid or powder fire extinguishing agent into the fire extinguishing bottle or the cooling bottle; the two three-way joints are respectively connected to the two manual ball valves, and form a first interface and a fifth interface respectively, the first interface is used to fill gas and gas fire extinguishing agent into the fire extinguishing bottle or the cooling bottle, and the fifth interface is used to adjust the pressure in the fire extinguishing bottle or the cooling bottle; the remaining passage of the two three-way joints forms a second interface and a fourth interface respectively.

6. The fire extinguishing and cooling efficiency test device for testing the fire extinguishing agent for lithium batteries in confined spaces according to claim 1, characterized in that: The delivery pipeline is connected to the center just above the test box through three consecutive 90° elbows at the end section of the delivery pipeline, and the fire extinguishing agent is sprayed onto the lithium batteries in the test box through the top plate of the test box.

7. The fire extinguishing and cooling efficiency test device for testing the fire extinguishing agent for lithium batteries in confined spaces according to claim 6, characterized in that: The delivery pipeline is fixed at the center of the top plate of the test box through a through-plate joint. The through-plate joint is connected to the delivery pipeline, and the end thereof is connected to a porous nozzle for diffuse spraying of the fire extinguishing agent.

8. The fire extinguishing and cooling efficiency test device for testing a fire extinguishing agent for a lithium battery in a confined space according to claim 1, characterized in that: The heating device includes a heating plate and a clamp, and the clamp fastens and connects the heating plate and the lithium battery adjacently.

9. A method for testing the fire extinguishing and cooling efficiency of a lithium battery fire extinguishing agent in a confined space, which is applied to the fire extinguishing and cooling efficiency testing device for testing the fire extinguishing and cooling efficiency of a lithium battery fire extinguishing agent in a confined space as claimed in any one of claims 1 to 8, characterized in that: It includes the following steps: S11. Load a lithium battery into the test chamber, and respectively load a fire extinguishing agent of the same configuration with a known filling amount m of fire extinguishing agent into the fire extinguishing bottle and the cooling bottle; S12, after heating the lithium battery to thermal runaway, disconnecting the power supply of the heating device; S13, detect the change of smoke concentration in the test chamber and send out a smoke alarm signal when the smoke concentration exceeds the limit; S14, controlling the fire extinguisher bottle to spray the fire extinguishing agent onto the lithium battery according to the smoke alarm signal; S15, detecting the delivery pressure of the fire extinguishing agent in the delivery pipeline; S16, photographing the lithium battery and identifying the time of fire onset and fire extinguishing of the lithium battery; S17. After the fire extinguisher bottle is sprayed and the delivery pressure is zero, the fire extinguisher bottle is controlled to be closed and the cooling bottle is activated to spray the corresponding fire extinguishing agent onto the lithium battery. The time difference between the activation time of the fire extinguisher bottle and the fire extinguishing time is calculated as the fire extinguishing time t used for fire extinguishing. The surface temperature T of the lithium battery is also collected after the cooling bottle is sprayed and the delivery pressure is zero; Repeat steps S11 to S17 to conduct experiments using the experimental device for fire extinguishing agents with the same filling volume but different types, or the same filling volume but different configurations, and record the filling volume m, fire extinguishing time t, and surface temperature T of the lithium battery in each test.

10. A method for designing an optimal fire extinguishing agent for lithium batteries in confined spaces, characterized in that: It includes the following steps: S21. Load a lithium battery into the test chamber, and respectively load a fire extinguishing agent of the same configuration with a known filling amount m of fire extinguishing agent into the fire extinguishing bottle and the cooling bottle; S22, heating the lithium battery until thermal runaway occurs and then stopping heating; S23, detect the change of smoke concentration in the test chamber and send out a smoke alarm signal when the smoke concentration exceeds the limit; S24, controlling the fire extinguisher bottle to spray the fire extinguishing agent onto the lithium battery according to the smoke alarm signal; S25, detecting the delivery pressure of the fire extinguishing agent ejected from the fire extinguishing bottle; S26. Photographing the lithium battery to identify the time of fire onset and the time of fire extinguishment of the lithium battery; S27. After the fire extinguisher bottle is sprayed and the delivery pressure is zero, the fire extinguisher bottle is controlled to be closed and the cooling bottle is activated to spray the corresponding fire extinguishing agent onto the lithium battery. The time difference between the activation time of the fire extinguisher bottle and the fire extinguishing time is calculated as the fire extinguishing time t used for fire extinguishing. The surface temperature T of the lithium battery is also collected after the cooling bottle is sprayed and the delivery pressure is zero; Repeat steps S21 to S27 to conduct separate experiments with different types of fire extinguishing agents with the same filling volume, or different configurations with the same filling volume. Record the filling volume m, fire extinguishing time t, and lithium battery surface temperature T for each test. S28. The fire extinguishing agent with the minimum filling amount m, fire extinguishing time t, and surface temperature T of the lithium battery is selected as the optimal fire extinguishing agent.

Images