A simulation device for lithium battery thermal runaway jet fire

Abstract

The present application relates to lithium battery safety test and thermal runaway protection technical field, disclose a kind of lithium battery thermal runaway jet fire simulation device, wherein high-temperature gas generation module includes burner, igniter, powder supply pipe, gas electric heater, powder generator, primary methane, air and carbon dioxide gas path, for producing temperature controllable high-temperature gas flow;Jet fire injection module includes mixing chamber, jet nozzle, hydrogen and secondary methane gas path, for simulating the injection gas component and injection state of lithium battery thermal runaway;State detection module is used to monitor the temperature and pressure change inside the device.The present application can simulate the characteristics of lithium battery thermal runaway jet fire under different types and charge states, can produce stable jet flame, and control the burning time and flow rate of flame, can provide experimental technical support for the evaluation of fire-retardant material on the fire-retardant performance of lithium battery thermal runaway jet fire.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium battery safety testing and thermal runaway protection, in particular to a lithium battery thermal runaway jet fire simulation device. BACKGROUND

[0002] With the development of new energy automobile field and energy storage industry, lithium batteries are widely used in production and life. In recent years, lithium battery fire accidents have occurred frequently, and their fire hazard has attracted widespread attention. Research has found that lithium batteries will undergo thermal runaway when subjected to external pressure, needle puncture and other conditions, and will spray high-temperature flammable gas, which will form a jet flame after mixing with air, causing fire and even explosion, which seriously threatens life and property safety. Therefore, the safety of lithium batteries has been highly valued by the state and relevant enterprises.

[0003] Different types of lithium battery thermal runaway produce significantly different jet fires, and the jet fires produced by the same type of lithium battery thermal runaway are also unstable. Lithium batteries are scrapped after a single thermal runaway jet fire test, and the cost of conducting large-scale parameterized experiments is high. In addition, real lithium battery jet fire experiments will produce a certain amount of toxic and harmful gases, polluting the environment and threatening the health of experimental personnel. In recent years, many scholars have tried to use new fire-resistant materials to suppress the influence range of lithium battery thermal runaway and reduce fire damage. To analyze the fire-retardant effect of fire-resistant materials on lithium batteries, a large number of experiments are needed to evaluate the basic performance and performance boundaries of fire-resistant materials, as well as the fire-retardant effect of materials on different types of lithium batteries.

[0004] Therefore, the present application provides a lithium battery thermal runaway jet fire simulation device to provide technical support for evaluating fire-retardant materials for lithium battery jet fires. SUMMARY

[0005] To solve the problems in the related art, the present application provides a lithium battery thermal runaway jet fire simulation device that accurately controls the inlet parameters (temperature, composition, pressure, etc.) of flammable gas to simulate the typical jet fire characteristics under thermal runaway conditions, better observe experimental phenomena, evaluate the fire-retardant effect of fire-resistant materials on lithium battery thermal runaway jet fires, and explore their performance boundaries, thereby overcoming the above technical problems existing in the prior art.

[0006] To this end, the specific technical solutions adopted by the present application are as follows:

[0007] A lithium battery thermal runaway jet fire simulation device includes a high-temperature gas generation module for forming a high-temperature gas stream according to the mixed gas of methane and air; a jet fire injection module for simulating the injection state of different types of lithium battery thermal runaway jet fires; and a state detection module for recording temperature and pressure changes during the reaction process.

[0008] The high-temperature gas generation module comprises a burner, an igniter, a powder supply pipe, a gas electric heater, a powder generator, a primary methane gas path, an air path and a carbon dioxide path.

[0009] The burner is used for changing the mixed gas of methane and air into high-temperature gas, and simultaneously coarsely adjusting the temperature by controlling the mixing ratio, so that the jet fire temperature at the jet outlet reaches the required value.

[0010] The igniter is used for igniting the mixed gas in the mixing chamber.

[0011] The powder supply pipe is used for conveying the carbon dioxide gas and the particulate matter.

[0012] The gas electric heater is used for finely adjusting the temperature of the carbon dioxide gas to accurately adjust the jet fire temperature at the jet outlet to the required value.

[0013] The powder generator is used for bringing the particulate matter in the generator into the mixing chamber by the flowing gas.

[0014] The primary methane gas path is used for conveying the required primary methane into the mixing chamber.

[0015] The air path is used for conveying the required air into the mixing chamber.

[0016] The carbon dioxide path is used for conveying the required carbon dioxide into the mixing chamber.

[0017] The jet fire jetting module comprises a mixing chamber, a jet nozzle, a hydrogen gas path and a secondary methane gas path.

[0018] The mixing chamber is used for mixing the formation of high-temperature gas and mixing the supplementary gas containing particulate matter to simulate the high-temperature jet of lithium battery thermal runaway.

[0019] The jet nozzle is threadedly connected to the top of the mixing chamber, and different diameter jet nozzles can be replaced according to the speed and height characteristics of the lithium battery thermal runaway jet fire.

[0020] The hydrogen gas path is used for conveying the required hydrogen into the mixing chamber.

[0021] The secondary methane gas path is used for conveying the required secondary methane into the mixing chamber.

[0022] The state detection module comprises a temperature sensor group, a pressure sensor group, a data acquisition instrument and a computer.

[0023] The temperature sensor group is used for monitoring the temperature at the mixing chamber and the jet fire outlet in real time.

[0024] The pressure sensor group is used for monitoring the pressure at the mixing chamber and the jet fire outlet in real time.

[0025] The data acquisition unit, connected to the temperature sensor group and the pressure sensor group, is used to record the temperature and pressure changes throughout the experiment.

[0026] A computer, connected to a data acquisition unit and an igniter, is used to record temperature and pressure data and control the igniter to ignite the flame.

[0027] Furthermore, the burner includes a housing, the inner bottom of which is provided with honeycomb ceramic, and the honeycomb ceramic is sealed and fixed to the housing by high-temperature resistant ceramic adhesive.

[0028] Furthermore, a carbon dioxide input section is provided at the bottom of the powder generator, and one side of the carbon dioxide input section is connected to the carbon dioxide gas passage. A microporous plate is provided in the middle of the powder generator, and particulate matter is provided at the top of the powder generator.

[0029] Furthermore, the mixing chamber includes a large-diameter section, a diameter-gradient section, and a small-diameter section arranged from bottom to top; wherein, the large-diameter section is used for the complete combustion of the mixture of methane and air; the diameter-gradient section is used for the complete mixing of the high-temperature mixture with supplemented carbon dioxide and particulate matter; and the small-diameter section is used for supplementing methane and hydrogen and mixing them thoroughly to better simulate the gas composition of a lithium battery jet fire.

[0030] Furthermore, the top of the mixing chamber is connected to the jet nozzle via a threaded connection, and the inner diameter of the jet nozzle gradually decreases from bottom to top. The bottom of the mixing chamber is connected to the shell, and the bottom of the burner is connected to the coal supply pipe via flanges.

[0031] Furthermore, the temperature sensor group consists of a first temperature sensor, a second temperature sensor, and a third temperature sensor. The first temperature sensor is installed on the inner wall of the top side of the large-diameter section in the mixing chamber to monitor the temperature after the methane and air are mixed and reacted. The second temperature sensor is installed on the inner wall of the top side of the diameter-gradient section in the mixing chamber to monitor the temperature after the high-temperature gas is mixed with carbon dioxide and particulate matter. The third temperature sensor is installed on the inner wall of the jet nozzle near the jet fire outlet to monitor the temperature of the ejected jet fire.

[0032] Furthermore, the pressure sensor group consists of a first pressure sensor, a second pressure sensor, and a third pressure sensor. The first pressure sensor is located on the inner wall of the top of the diameter-gradient section in the mixing chamber, and is used to monitor pressure changes in the device. The second pressure sensor is located on the inner wall of the top of the small-diameter section in the mixing chamber, and is used to monitor the pressure in the device after the methane and hydrogen gases are replenished. The third pressure sensor is located on the inner wall of the jet nozzle near the jet fire outlet, and is used to monitor the pressure of the ejected jet fire.

[0033] The beneficial effects of this invention are as follows:

[0034] 1) This invention can simulate the characteristics of thermal runaway jet fire of different types of lithium batteries under different conditions, and can generate stable jet flames and control the combustion time and flow rate of the flames, thereby providing experimental technical support for evaluating the fire-retardant performance of fire-retardant materials against thermal runaway jet fire of lithium batteries.

[0035] 2) This invention can precisely control parameters such as the temperature, gas composition, particulate matter content, gas pressure, and nozzle diameter of the gas jet to simulate the characteristics of thermal runaway jet fires in different types of lithium batteries. The resulting stable jet fire is more suitable for quantitative analysis of the performance boundaries and fire-retardant mechanisms of flame-retardant materials. This simulation device has advantages such as safety, stability, environmental friendliness, and recyclability of its main structure.

[0036] 3) This invention can simulate different types of lithium batteries by setting different temperatures, particulate matter content and pressures of high-temperature combustible gas jets. Compared with using different types of lithium batteries to conduct thermal runaway experiments, this device can simulate different types of lithium batteries on one device, making the entire experimental process simpler and more convenient, and better controlling a single variable to ensure the accuracy of experimental data, while also saving experimental costs.

[0037] 4) This invention can generate a continuous and stable jet fire, control the duration of the flame, and allow for direct observation of experimental phenomena. By changing the duration of the jet fire, the fire-retardant effect of the flame-retardant material on the thermal runaway jet fire of lithium batteries can be better explored.

[0038] 5) This invention can control the length and speed of the jet fire by adjusting the flow meter, so as to simulate the characteristics of the jet fire generated by the thermal runaway of lithium battery under different charging states, and explore the fire-retardant ability of the fire-retardant material for jet fire under different states, thereby determining the performance boundary of the fire-retardant material. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of a simulation device for thermal runaway jet fire of a lithium battery according to an embodiment of the present invention.

[0041] In the picture:

[0042] 1. First methane cylinder; 2. First switching valve; 3. First flow meter; 4. First back pressure valve; 5. Air cylinder; 6. Second switching valve; 7. Second flow meter; 8. Second back pressure valve; 9. Carbon dioxide cylinder; 10. Third switching valve; 11. Third flow meter; 12. Third back pressure valve; 13. Powder generator; 14. Gas electric heater; 15. Burner; 15.1. Housing; 15.2. Honeycomb ceramic; 16. Powder supply pipe; 17. Mixing chamber; 18. Ignition. Devices; 19. Second methane cylinder; 20. Fifth switch valve; 21. Fifth flow meter; 22. Fifth back pressure valve; 23. Hydrogen cylinder; 24. Fourth switch valve; 25. Fourth flow meter; 26. Fourth back pressure valve; 27. First temperature sensor; 28. Second temperature sensor; 29. ​​Third temperature sensor; 30. First pressure sensor; 31. Second pressure sensor; 32. Third pressure sensor; 33. Data acquisition instrument; 34. Computer; 35. Jet nozzle. Detailed Implementation

[0043] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0044] According to an embodiment of the present invention, a device for simulating thermal runaway jet fire in a lithium battery is provided.

[0045] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments, such as... Figure 1 As shown, the simulation device for lithium battery thermal runaway jet fire according to an embodiment of the present invention includes:

[0046] A high-temperature gas generating module is used to generate a high-temperature gas flow based on the mixture of methane and air introduced into the system.

[0047] The jet fire injection module is used to simulate the jet fire injection state of different types of lithium battery thermal runaway, including the temperature, length and velocity of the jet flame;

[0048] The state monitoring module is used to record temperature and pressure changes during the reaction process;

[0049] The high-temperature gas generating module includes a burner 15, an igniter 18, a powder supply pipe 16, a gas electric heater 14, a powder generator 13, a primary methane gas path, an air gas path, and a carbon dioxide gas path. It generates a high-temperature gas flow by introducing a mixture of methane and air, with the methane-to-air ratio exceeding the stoichiometric ratio, placing the high-temperature gas flow in a fuel-rich state. Carbon dioxide and particulate matter are supplemented through the powder supply pipe 16 to initially simulate a jet fire. Simultaneously, the gas electric heater 14 precisely regulates the temperature within the mixing chamber 17 to simulate the temperature of the high-temperature combustible gas generated by thermal runaway in a lithium battery. Each gas path includes a high-pressure gas cylinder, valves, a flow meter, a back pressure valve, and pipes connecting these components.

[0050] The burner 15 is used to convert the mixture of methane and air into a high-temperature gas, and at the same time, the temperature is coarsely adjusted by controlling the mixing ratio so that the jet fire temperature at the injection outlet reaches the required level.

[0051] Specifically, the burner 15 includes a housing 15.1, and a honeycomb ceramic 15.2 is provided at the bottom of the inner part of the housing 15.1. The honeycomb ceramic 15.2 is sealed and fixed to the housing 15.1 by high-temperature resistant ceramic adhesive. The mixture of methane and air is introduced from the lower side of the burner 15 through a honeycomb pipe. The methane and air are fully mixed before being delivered to facilitate better combustion. At the same time, an igniter 18 is installed on the right side of the horizontal plane of the combustion plane of the burner 15.

[0052] Ignition device 18 is used to ignite the mixed gas in the mixing chamber;

[0053] The coal supply pipe 16 is used to transport carbon dioxide gas and particulate matter; specifically, the coal supply pipe 16 transports carbon dioxide and particulate matter from the center of the burner 15 upwards to the mixing chamber 17.

[0054] Gas electric heater 14 is used to fine-tune the temperature of carbon dioxide gas to precisely adjust the jet fire temperature at the injection outlet to meet the required requirements.

[0055] Powder generator 13 is used to carry particulate matter from the generator into the mixing chamber by flowing gas;

[0056] Specifically, the powder generator 13 is divided into three parts: the lower part is for carbon dioxide gas input, the middle part is a microporous plate, and the upper part contains alumina and other particulate matter. After passing through the powder generator 13, the carbon dioxide gas carries the particulate matter through the gas electric heater 14 and then enters the mixing chamber 17 through the powder supply pipe, where it mixes with the high-temperature gas. The temperature of the solid-gas mixture is adjusted by the gas electric heater 14. Simultaneously, after adjusting the system temperature, the methane and hydrogen content in the mixing chamber 17 is replenished through a secondary methane gas path and a hydrogen gas path, while the flow rate and pressure of the jet fire are controlled.

[0057] The primary methane gas path is used to deliver the required primary methane to the mixing chamber;

[0058] Specifically, the primary methane gas circuit includes a first methane gas cylinder 1, a first switching valve 2, a first flow meter 3 and a first back pressure valve 4 connected in sequence, and the other end of the first back pressure valve 4 is connected to one side of the bottom of the burner 15.

[0059] Air passage, used to deliver the required air to the mixing chamber;

[0060] Specifically, the air circuit includes an air cylinder 5, a second switching valve 6, a second flow meter 7 and a second back pressure valve 8 connected in sequence, and the other end of the second back pressure valve 8 is connected to one side of the bottom of the burner 15.

[0061] The carbon dioxide gas path is used to deliver the required carbon dioxide to the mixing chamber;

[0062] Specifically, the carbon dioxide gas circuit includes a carbon dioxide gas cylinder 9, a third switching valve 10, a third flow meter 11 and a third back pressure valve 12 connected in sequence, and the other end of the third back pressure valve 12 is connected to one end of the powder generator 13. The other end of the powder generator 13 is connected to the bottom end of the powder supply pipe 16 through a gas electric heater 14.

[0063] In this embodiment, the burner 15 in the high-temperature gas generating module includes a housing 15.1 and honeycomb ceramics 15.2. The lower wall of the housing 15.1 has an inlet pipe for transporting a mixture of methane and air. The gas is delivered to the combustion plane through a honeycomb-shaped pipe composed of the honeycomb ceramics 15.2. Each inlet pipe is equipped with a switching valve, a flow meter, and a back pressure valve. These three devices can be controlled to adjust the flow rate and ratio of methane and air, ensuring the methane-to-air ratio is higher than the stoichiometric ratio, thus achieving a fuel-rich combustion state. Simultaneously, a first temperature sensor 27 and an igniter 18 are installed on the inner wall of the combustion plane. The first temperature sensor 27 is electrically connected to a data acquisition instrument 33, and the igniter 18 is connected to a computer 34 to control ignition. After the mixture is delivered to the combustion plane, the igniter 18 ignites the premixed gas, generating a high-temperature flame.

[0064] In the high-temperature gas generation module, the carbon dioxide gas path, powder generator 13, gas electric heater 14, and powder supply pipe 16 continuously transport the solid-gas mixture to the mixing chamber 17. After passing through the on / off valve, flow meter, and back pressure valve, the carbon dioxide gas carries away particulate matter from the powder generator 13, forming a solid-gas mixture. Simultaneously, the solid-gas mixture is heated by the gas electric heater 14 to a temperature range of 100-1500℃. After heating, the solid-gas mixture is carried into the mixing chamber 17 through the powder supply pipe 16, where it is thoroughly mixed with the high-temperature flame, simultaneously regulating the flame temperature.

[0065] The jet fire injection module includes a mixing chamber 17, a jet nozzle 35, a hydrogen gas path, and a secondary methane gas path;

[0066] The mixing chamber 17 is used to mix the high-temperature gas and the supplementary gas containing particulate matter to simulate the high-temperature ejection of lithium battery thermal runaway; and the burner 15, the mixing chamber 17, and the powder supply pipe 16 have the characteristics of high temperature and high pressure resistance and strong airtightness.

[0067] Specifically, the diameter of the mixing chamber 17 gradually decreases; the large-diameter section allows for the complete combustion of the methane and air mixture; the diameter-gradient section allows for the complete mixing of the high-temperature mixture with the supplemented carbon dioxide and particulate matter; and the small-diameter section allows for the supplementation of methane and hydrogen, and complete mixing, to better simulate the gas composition of a lithium battery jet fire.

[0068] The top of the mixing chamber 17 is tightly connected to the jet nozzle 35 by threads, and the inner diameter of the jet nozzle 35 gradually decreases from bottom to top. The bottom of the mixing chamber 17 is tightly connected to the shell 15.1 and the bottom of the burner 15 is tightly connected to the powder supply pipe 16 by flanges, and the entire system is in a closed state.

[0069] The jet nozzle 35 has a circular cross-section and is replaceable. The corresponding jet nozzle size can be selected according to the safety valve nozzle size of the different types of lithium batteries to be simulated, and it is tightly installed on the main body device by threads.

[0070] Hydrogen gas path, used to deliver the required hydrogen to the mixing chamber;

[0071] Specifically, the hydrogen gas path includes a hydrogen cylinder 23, a fourth switch valve 24, a fourth flow meter 25 and a fourth back pressure valve 26 connected in sequence, and the other end of the fourth back pressure valve 26 is connected to the small diameter section of the mixing chamber 17.

[0072] Secondary methane gas path, used to deliver the required secondary methane to the mixing chamber;

[0073] Specifically, the secondary methane gas path includes a second methane gas cylinder 19, a fifth switching valve 20, a fifth flow meter 21, and a fifth back pressure valve 22 connected in sequence, and the other end of the fifth back pressure valve 22 is connected to the small diameter section of the mixing chamber 17.

[0074] In this embodiment, the jet fire injection module primarily functions as a jet fire injection unit, with secondary methane and hydrogen gas paths in the small-diameter section. According to relevant research, the main gas components in a lithium-ion battery jet fire are hydrogen and carbon dioxide, followed by methane. Therefore, secondary supplementation is implemented to better simulate the gas composition. Furthermore, due to the extremely low ignition energy and wide flammability limit of hydrogen reacting with air, supplementation at the upstream end of the device is not suitable. The volume fraction of hydrogen in the entire mixture can range from 0-40%, and the volume fraction of carbon dioxide can range from 0-50%. Hydrogen and carbon dioxide constitute the majority of the mixture, while methane, ethane, and carbon monoxide constitute a smaller portion. Methane gas enters the device through a switching valve, flow meter, and back pressure valve, while hydrogen gas enters the device through the same valve to fully simulate the gas composition of a lithium-ion battery jet fire. Additionally, the jet nozzle 35 in the system is replaceable, with a replaceable size range of 1-30 mm.

[0075] The status detection module includes a temperature sensor group, a pressure sensor group, a data acquisition instrument 33, and a computer 34;

[0076] Specifically, the status monitoring system includes three sets of temperature sensors and three sets of pressure sensors. The sensor contacts are arranged on the inner walls of the mixing chamber 17 and the small-diameter section device. The tail of the sensor is connected to the data acquisition unit 33, which is connected to the computer 34 to transmit the recorded data. Simultaneously, the computer 34 controls the igniter 18 to perform ignition.

[0077] Temperature sensor array for real-time monitoring of the temperature at the mixing chamber and jet fire outlet;

[0078] Specifically, the temperature sensor group consists of a first temperature sensor 27, a second temperature sensor 28, and a third temperature sensor 29. The first temperature sensor 27 is installed on the inner wall of the horizontal plane of the combustion plane to monitor the temperature of the methane-air mixture after ignition. The second temperature sensor 28 is installed on the inner wall 10mm from the top surface of the powder supply pipe 16 in the mixing chamber to monitor the temperature of the high-temperature gas-solid mixture after uniform mixing in the mixing chamber 17. The third temperature sensor 29 is installed near the jet flame outlet of the jet nozzle 35 to detect the flame temperature during jet flame injection, ensuring that the temperature meets the experimental requirements. The tails of the three temperature sensors are connected to a data acquisition unit 33, which is connected to a computer 34 to transmit the recorded data. All three temperature sensors use K-type thermocouples. By observing the temperature data measured by the three temperature sensors, the temperature is coarsely adjusted by regulating the reaction rate using a flow meter, and finely adjusted by setting the temperature in the gas electric heater, so that the temperature at the jet outlet reaches the jet flame temperature required for the flame-retardant material testing experiment.

[0079] A pressure sensor array is used to monitor the pressure in the mixing chamber and at the jet fire outlet in real time;

[0080] Specifically, the pressure sensor group consists of a first pressure sensor 30, a second pressure sensor 31, and a third pressure sensor 32. The first pressure sensor 30 is located on the inner wall 10mm from the top surface of the powder supply pipe 16 in the mixing chamber 17, used to monitor pressure changes within the device. The second pressure sensor 31 is located on the inner wall of the downstream device after the small-diameter section of methane and hydrogen gas replenishment, used to monitor the pressure within the device after the replenishment of methane and hydrogen gas, so as to better adjust the pressure in the device subsequently. The third pressure sensor 32 is located on the inner wall of the jet nozzle 35 near the jet fire outlet, used to monitor the pressure of the ejected jet fire. The tails of the three pressure sensors are connected to a data acquisition unit 33, transmitting data to a computer 34 via electrical signals. The monitored pressure data at the nozzle is used to adjust the valves in each gas path to achieve the simulated pressure required for the experiment.

[0081] The data acquisition unit 33 is connected to the temperature sensor group and the pressure sensor group to record the temperature and pressure changes throughout the experiment.

[0082] Computer 34, connected to the data acquisition unit and igniter, is used to record temperature and pressure data and control the igniter to ignite.

[0083] In this embodiment, the status monitoring module mainly transmits temperature data from three sets of temperature sensors and pressure data from three sets of pressure sensors to the data acquisition unit 33, and then imports the data into the computer 34 for storage and analysis via electrical connection. The temperature and pressure data are observed to adjust the temperature and pressure within the device in a timely manner. Simultaneously, the computer controls the igniter 18 to perform the ignition operation.

[0084] In summary, this invention proposes a simulation device for lithium battery thermal runaway jet fire. Firstly, it can control fuel flow rate, combustion temperature, flow rate, and pressure by adjusting a flow meter, unlike the uncontrollable nature of lithium battery thermal runaway reactions. With this device, if a dangerous situation occurs, the jet flame can be extinguished immediately and the experiment stopped. Secondly, it can observe the temperature at each stage using temperature detectors, and change the set temperature and temperature rise rate to simulate the temperature characteristics of different types of lithium battery thermal runaway jet fires. Thirdly, it can monitor data from three sets of pressure detectors and adjust the flow meter to control the pressure and flow rate of the device, thus simulating the pressure characteristics of different types of lithium battery thermal runaway jet fires. Fourthly, it can simulate lithium batteries at different states of charge by controlling the flow rate and flow rate of different gas components and the particulate matter content. Furthermore, it can replace jet nozzles of different sizes to simulate different types of lithium batteries, allowing for better analysis of the fire-retardant performance of flame-retardant materials for different types of lithium battery thermal runaway jet fires.

[0085] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0086] 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, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for simulating thermal runaway jet fire in lithium batteries, characterized in that, include: A high-temperature gas generating module is used to generate a high-temperature gas flow based on the mixture of methane and air introduced into the system. The jet fire injection module is used to simulate the jet fire injection state of different types of lithium battery thermal runaway. The status detection module is used to monitor changes in temperature and pressure inside the device; The high-temperature gas generating module includes a burner (15), an igniter (18), a powder supply pipe (16), a gas electric heater (14), a powder generator (13), a primary methane gas path, an air gas path, and a carbon dioxide gas path. The burner (15) is used to convert the mixture of methane and air into a high-temperature gas, and at the same time, the temperature is coarsely adjusted by controlling the mixing ratio so that the jet fire temperature at the injection outlet reaches the required level. The igniter (18) is used to ignite the mixed gas in the mixing chamber. The powder supply pipe (16) is used to transport carbon dioxide gas and particulate matter; The gas electric heater (14) is used to fine-tune the temperature of carbon dioxide gas to precisely adjust the jet fire temperature at the injection outlet to meet the required requirements. The powder generator (13) is used to carry particulate matter from the generator into the mixing chamber by the flow of gas. The primary methane gas path is used to deliver the required primary methane to the mixing chamber; The air passage is used to deliver the required air to the mixing chamber; The carbon dioxide gas path is used to deliver the required carbon dioxide to the mixing chamber; The jet fire injection module includes a mixing chamber (17), a jet nozzle (35), a hydrogen gas path, and a secondary methane gas path; The mixing chamber (17) is used to mix the formation of high-temperature gas and mix supplementary gas containing particulate matter to simulate the high-temperature jet of lithium battery thermal runaway; The jet nozzle (35) is threadedly connected to the top of the mixing chamber, and different diameter jet nozzles can be replaced according to the velocity and height characteristics of the lithium battery thermal runaway jet fire. The hydrogen gas path is used to deliver the required hydrogen to the mixing chamber; The secondary methane gas path is used to deliver the required secondary methane to the mixing chamber; The status detection module includes a temperature sensor group, a pressure sensor group, a data acquisition instrument (33), and a computer (34). The temperature sensor group is used to monitor the temperature at the mixing chamber and the jet fire outlet in real time; The pressure sensor array is used to monitor the pressure at the mixing chamber and the jet fire outlet in real time; The data acquisition instrument (33) is connected to the temperature sensor group and the pressure sensor group to record the temperature and pressure changes throughout the experiment. The computer (34) is connected to the data acquisition unit and the igniter to record temperature and pressure data and control the igniter to ignite.

2. The simulation device for lithium battery thermal runaway jet fire according to claim 1, characterized in that, The burner (15) includes a housing (15.1), and a honeycomb ceramic (15.2) is provided at the bottom of the inner part of the housing (15.1). The honeycomb ceramic (15.2) and the housing (15.1) are sealed and fixed by high-temperature resistant ceramic adhesive.

3. The simulation device for thermal runaway jet fire of a lithium battery according to claim 1, characterized in that, The powder generator (13) has a carbon dioxide input section at its bottom, and one side of the carbon dioxide input section is connected to the carbon dioxide gas path. The powder generator (13) has a microporous plate in its middle part and particulate matter in its top part.

4. The simulation device for lithium battery thermal runaway jet fire according to claim 1, characterized in that, The mixing chamber (17) includes a large-diameter section, a diameter-gradient section and a small-diameter section arranged from bottom to top; The large-diameter section is used for the complete combustion of the mixture of methane and air; The diameter-gradient section is used to fully mix the high-temperature mixed gas with the supplemented carbon dioxide and particulate matter; The small-diameter section is used to replenish methane and hydrogen and mix them thoroughly, better simulating the gas composition of a lithium battery jet fire.

5. The simulation device for thermal runaway jet fire of a lithium battery according to claim 1, characterized in that, The top of the mixing chamber (17) is connected to the jet nozzle (35) by a thread, and the inner diameter of the jet nozzle (35) gradually decreases from bottom to top.

6. The simulation device for thermal runaway jet fire of a lithium battery according to claim 2, characterized in that, The bottom end of the mixing chamber (17) is connected to the shell (15.1) and the bottom end of the burner (15) is connected to the powder supply pipe (16) via flanges.

7. The simulation device for thermal runaway jet fire of a lithium battery according to claim 4, characterized in that, The temperature sensor group consists of a first temperature sensor (27), a second temperature sensor (28), and a third temperature sensor (29); The first temperature sensor (27) is installed on the inner wall of the top side of the large-diameter section in the mixing chamber (17) to monitor the temperature after the methane and air are mixed and reacted. The second temperature sensor (28) is installed on the inner wall of the top side of the diameter gradient section in the mixing chamber (17) to monitor the temperature of the mixture of high temperature gas, carbon dioxide and particulate matter. The third temperature sensor (29) is installed on the inner wall of the jet nozzle (35) near the jet fire outlet to monitor the temperature of the ejected jet fire.

8. The simulation device for thermal runaway jet fire of a lithium battery according to claim 4, characterized in that, The pressure sensor group consists of a first pressure sensor (30), a second pressure sensor (31), and a third pressure sensor (32); The first pressure sensor (30) is installed on the inner wall of the top of the diameter gradient section in the mixing chamber (17) to monitor pressure changes in the device. The second pressure sensor (31) is installed on the inner wall of the top of the small diameter section in the mixing chamber (17) to monitor the pressure in the device after the methane and hydrogen gases are replenished. The third pressure sensor (32) is installed on the inner wall of the jet nozzle (35) on the other side near the jet fire outlet, and is used to monitor the pressure of the jet fire.

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