Structure for preventing battery pack thermal runaway explosion-proof valve from being on fire, battery pack and automobile

Abstract

The invention discloses a structure for preventing a battery pack from thermal runaway and an explosion-proof valve from being on fire, the battery pack and an automobile. The structure is configured to be a structure for inhibiting a fire disaster of a core pack and the explosion-proof valve through a fire extinguishing agent. The battery pack box body is provided with a fire extinguishing agent interlayer in which a fire extinguishing agent is stored; the fire extinguishing agent interlayer is provided with a fire extinguishing agent pressure relief opening, and the fire extinguishing agent pressure relief opening is sealed through a fire extinguishing device blasting diaphragm. The fire extinguishing device is provided with a detonating assembly, and the detonating assembly is used for damaging a blasting diaphragm of the fire extinguishing device to release the fire extinguishing agent in the fire extinguishing agent interlayer when the core bag is in thermal runaway and guiding the fire extinguishing agent to the core bag and the anti-explosion valve. According to the structure for preventing the battery pack thermal runaway explosion-proof valve from firing, the battery pack with the structure and the new energy automobile, the structure can effectively and rapidly reduce the temperature of the battery pack with thermal runaway, meanwhile, firing combustion caused by thermal runaway of the battery pack is restrained for a long time, more serious thermal diffusion of the whole pack is prevented, and the service life of the battery pack is prolonged. And the safety of the whole vehicle and a passenger compartment is further ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of battery pack thermal runaway protection and battery pack fire suppression, and in particular to a structure for preventing a battery pack thermal runaway explosion-proof valve from catching fire, as well as a battery pack and a new energy vehicle having the structure. Background Art

[0002] When a battery pack cell experiences thermal runaway, the high-temperature, high-pressure, solid-liquid-gas three-phase mixture it produces is mainly depressurized through the battery pack's explosion-proof valve; and when the explosion-proof valve discharges the thermal runaway flue gas of the cell, the discharged combustible gas comes into contact with oxygen in the air. When the combustible gas reaches its combustion limit, the combustible gas is often ignited by the high-temperature solid and further causes more serious heat spread between the battery cells.

[0003] In existing technology, when a single cell or battery module experiences thermal runaway, the explosion-proof valve of the single cell opens, generating high-temperature solids (separator, positive and negative electrode plates), high-temperature liquids (electrolyte), and high-temperature gases (electrochemical reactants) that are directly ejected into the battery pack and then rapidly diffuse throughout the entire battery pack. When the flue gas accumulates to a certain pressure within the battery pack, the explosion-proof valve opens to release the pressure. The flue gas discharged by the explosion-proof valve mainly consists of CO, CO2, C2H2, H2, CH4, etc., as well as some high-temperature solids. When the combustible gases in the flue gas discharged by the explosion-proof valve come into contact with air and reach a combustible concentration, the discharged high-temperature solids become an ignition source. However, most current mass-produced explosion-proof valve designs do not have the function of suppressing the explosion-proof valve from igniting. Therefore, when the combustible gases at the tail end of the explosion-proof valve ignite, the internal temperature of the battery pack rises sharply, exacerbating the thermal diffusion of the battery pack and posing a greater threat to the vehicle and personnel. Based on the conventional structure in the prior art, it is not difficult to find that the battery pack in the prior art can only be vented and depressurized through the explosion-proof valve, but does not have the function of cooling and suppressing fire.

[0004] Therefore, based on the above technical problems, technicians in this field urgently need to develop a structure for preventing the fire of the battery pack's thermal runaway explosion-proof valve, as well as a battery pack and new energy vehicle with such a structure. Summary of the Invention

[0005] The purpose of the present invention is to provide a structure for preventing the fire of a battery pack's thermal runaway explosion-proof valve, as well as a battery pack and new energy vehicle having such a structure. The structure can effectively and quickly reduce the temperature of a battery pack in thermal runaway, and at the same time, suppress the fire and combustion of the battery pack caused by thermal runaway for a long time, prevent more serious heat diffusion of the entire pack, and further ensure the safety of the entire vehicle and the passenger compartment.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a structure for preventing fire caused by a thermal runaway explosion-proof valve of a battery pack. The structure is a fire extinguishing device. The explosion-proof valve is integrated into the end of the battery pack box, and the fire extinguishing device is arranged near the explosion-proof valve.

[0008] The fire extinguishing device is configured to suppress the fire of the core package and the explosion-proof valve by using a fire extinguishing agent;

[0009] The battery pack box has a fire extinguishing agent interlayer, and the fire extinguishing agent is stored in the fire extinguishing agent interlayer;

[0010] The fire extinguishing agent interlayer has a fire extinguishing agent pressure relief port, and the fire extinguishing agent pressure relief port is closed by a bursting diaphragm of a fire extinguishing device;

[0011] The fire extinguishing device has an ignition component, which is used to destroy the bursting membrane of the fire extinguishing device when the core package is thermally out of control, release the fire extinguishing agent in the fire extinguishing agent interlayer, and guide the fire extinguishing agent to the core package and the explosion-proof valve.

[0012] Furthermore, the battery pack box is divided into an inner wall and an outer wall of the box;

[0013] The space inside the inner wall of the box is the accommodating space for the core package;

[0014] The space between the inner wall of the box and the outer wall of the box is a fire extinguishing agent interlayer surrounding the battery pack box;

[0015] The position of the battery pack case where the explosion-proof valve is installed has a groove extending along the corresponding edge of the battery pack case, and the detonation assembly is arranged at the end of the groove close to the explosion-proof valve.

[0016] Furthermore, the groove and the fire extinguishing agent interlayer are separated by a structural wall, and the fire extinguishing agent pressure relief port is provided on the structural wall;

[0017] One end of the fire extinguishing agent pressure relief port communicating with the fire extinguishing agent interlayer is connected to the fire extinguishing device bursting diaphragm;

[0018] The fire extinguishing agent pressure relief port is in an open state at one end that cooperates with the detonation component;

[0019] The inner wall of the battery pack box is provided with a fire extinguishing agent box internal discharge port, and the fire extinguishing agent discharged from the fire extinguishing agent pressure relief port enters the accommodating space of the core pack through the fire extinguishing agent box internal discharge port;

[0020] The detonation assembly is provided with a fire extinguishing agent explosion-proof valve discharge port, and the fire extinguishing agent discharged from the fire extinguishing agent pressure relief port enters the tank through the fire extinguishing agent explosion-proof valve discharge port.

[0021] Furthermore, the discharge port in the fire extinguishing agent box and the discharge port of the fire extinguishing agent explosion-proof valve are both configured as conical discharge ports;

[0022] The conical discharge port is configured as a structure with an inner diameter gradually decreasing from the fire extinguishing agent inlet end to the fire extinguishing agent discharge end.

[0023] Furthermore, the detonation assembly includes:

[0024] An outer body of the detonating assembly is installed in the groove and has a certain gap between it and the fire extinguishing agent pressure relief port;

[0025] An inner body of the detonating assembly is mounted at the center of the outer body of the detonating assembly, and an air guide is formed on one end of the inner body of the detonating assembly near the fire extinguishing agent pressure relief port, and the air guide partially extends into the fire extinguishing agent pressure relief port; and

[0026] trigger structure;

[0027] The trigger structure includes:

[0028] A trigger chamber is installed in the main body of the detonation assembly, and the trigger chamber contains ignition powder. The trigger chamber is equipped with a conductor and a resistance wire connected to the conductor at one end opposite to the ignition powder. The conductor is energized and heats the resistance wire to ignite the ignition powder through the resistance wire.

[0029] A trigger structure bursting disk is provided at the end of the trigger cavity.

[0030] Furthermore, the fire extinguishing device bursting disk and the trigger structure bursting disk are both aluminum bursting disks with a bearing pressure of 4MPa-5MPa;

[0031] The inner wall of the battery pack box is a 6061 aluminum structure with a sealing pressure bearing capacity greater than 7MPa.

[0032] Furthermore, the ignition powder is 165 mg of potassium zirconium perchlorate;

[0033] The conductor is copper with a diameter of 2 mm, and the resistance wire is welded to the conductor;

[0034] The fire extinguishing agent is perfluorohexanone fire extinguishing agent.

[0035] The present invention also discloses a battery pack, wherein the battery pack box of the battery pack is integrated with the fire extinguishing device as described above.

[0036] The present invention further discloses a car, which is a new energy car and is integrated with the battery pack described above.

[0037] Furthermore, when the core pack in the battery pack of the vehicle undergoes thermal runaway and drives the internal pressure of the battery pack to increase, the explosion-proof valve opens and releases pressure, and the vehicle transmits an alarm signal to the BMS. The BMS emits a current of 1.75A with a duration greater than 100ms through the thermal runaway alarm strategy, and transmits the current to the conductor to drive the resistance wire to generate resistive ohmic heat to ignite the ignition powder.

[0038] In the above technical solution, the present invention provides a structure for preventing fire of a battery pack thermal runaway explosion-proof valve, which has the following beneficial effects:

[0039] The present invention provides a structure for preventing a battery pack explosion-proof valve from catching fire due to thermal runaway, as well as a battery pack and a new energy vehicle having the structure. The structure can effectively and quickly reduce the temperature of a battery pack in thermal runaway, and at the same time, suppress the fire and combustion of the battery pack caused by thermal runaway for a long time, thereby preventing more serious heat diffusion of the entire pack and further ensuring the safety of the entire vehicle and the passenger compartment. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0041] Figure 1 A schematic diagram of the structure of a battery pack explosion-proof valve for preventing thermal runaway fire disclosed in an embodiment of the present application;

[0042] Figure 2 A cross-sectional view of a structure for preventing a battery pack thermal runaway explosion-proof valve from catching fire, disclosed in an embodiment of the present application;

[0043] Figure 3 A schematic structural diagram of a fire extinguishing device disclosed in an embodiment of the present application for preventing a fire in a battery pack thermal runaway explosion-proof valve;

[0044] Figure 4 A diagram showing the opening positions of two discharge ports for a fire extinguishing agent of a fire extinguishing device for preventing a fire caused by a thermal runaway explosion-proof valve of a battery pack disclosed in an embodiment of the present application;

[0045] Figure 5 This is a cross-sectional view of the structure of the fire extinguishing device disclosed in an embodiment of the present application for preventing the fire of the battery pack thermal runaway explosion-proof valve.

[0046] Description of reference numerals:

[0047] 10. Battery pack box; 11. Explosion-proof valve; 12. Box outer wall; 13. Box inner wall; 14. Fire extinguishing agent interlayer; 15. Slot; 16. Core pack;

[0048] 1. Fire extinguishing device; 2. Detonation assembly;

[0049] 101. Fire extinguishing agent pressure relief port; 102. Fire extinguishing device bursting diaphragm;

[0050] 1401, fire extinguishing agent filling port; 1402, fire extinguishing agent battery box discharge port; 1403, fire extinguishing agent explosion-proof valve discharge port;

[0051] 201. External body of the detonating assembly; 202. Internal body of the detonating assembly; 203. Gas tube; 204. Conductor; 205. Resistance wire; 206. Ignition powder; 207. Bursting diaphragm of the detonating assembly. DETAILED DESCRIPTION

[0052] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0053] See also Figures 1 to 5 As shown;

[0054] This embodiment discloses a structure for preventing fire caused by a thermal runaway explosion-proof valve in a battery pack. The structure comprises a fire extinguishing device 1. An explosion-proof valve 11 is integrated into the end of a battery pack box 10, and the fire extinguishing device 1 is disposed near the explosion-proof valve 11.

[0055] The fire extinguishing device 1 is configured as a structure that suppresses fires in the core package 16 and the explosion-proof valve 11 by using a fire extinguishing agent;

[0056] The battery pack box 10 has a fire extinguishing agent interlayer 14, and the fire extinguishing agent interlayer 14 stores the fire extinguishing agent;

[0057] The fire extinguishing agent interlayer 14 has a fire extinguishing agent pressure relief port 101, and the fire extinguishing agent pressure relief port 101 is closed by a fire extinguishing device bursting disk 102;

[0058] The fire extinguishing device 1 has an ignition assembly 2, which is used to destroy the bursting disc 102 of the fire extinguishing device when the core package 16 thermally runs away, release the fire extinguishing agent in the fire extinguishing agent interlayer 14, and guide the fire extinguishing agent to the core package 16 and the explosion-proof valve 11.

[0059] First, if Figure 1 and Figure 2 As shown, this embodiment discloses a structure for preventing fire from the explosion-proof valve of a battery pack due to thermal runaway, namely the fire extinguishing device 1 mentioned above. The fire extinguishing device 1 is arranged close to the explosion-proof valve 11 and integrated into the design position of the battery pack box 10. In addition, Figure 2Also shown is the fire extinguishing agent interlayer 14 designed to be formed in the battery pack case 10. In this application, a certain amount of fire extinguishing agent is stored in the fire extinguishing agent interlayer 14, and when the core pack 16 thermally runs away, the fire extinguishing device 1 also guides the fire extinguishing agent in the fire extinguishing agent interlayer 14 to a designated position of the battery pack case 10, and serves as a measure to suppress fire of the core pack 16 and the explosion-proof valve 11.

[0060] See also Figures 3 to 5 As shown, the fire extinguishing device 1 of this embodiment has an ignition assembly 2, which cooperates with the fire extinguishing device bursting diaphragm 102 of the fire extinguishing device 1 and explodes in the thermal runaway state to break the fire extinguishing device bursting diaphragm 102, thereby releasing the fire extinguishing agent in the fire extinguishing agent interlayer 14, thereby suppressing the core package 16 and the explosion-proof valve 11 from catching fire.

[0061] In summary, the fire extinguishing device 1 of this embodiment can not only ensure that the battery pack is depressurized through the explosion-proof valve 11, but also suppress the fire of the core pack 16 and the explosion-proof valve 11 through the fire extinguishing agent of the fire extinguishing device 1.

[0062] Preferably, the battery pack box 10 of this embodiment is divided into a box inner wall 13 and a box outer wall 12;

[0063] The space inside the inner wall 13 of the box in this embodiment is the accommodating space for the core package 16;

[0064] The space between the inner wall 13 and the outer wall 12 of the box body is a fire extinguishing agent interlayer 14 surrounding the battery pack box body 10;

[0065] The battery pack case 10 where the explosion-proof valve 11 is installed has a groove 15 extending along the corresponding side of the battery pack case 10 , and the detonation assembly 2 is arranged at the end of the groove 15 close to the explosion-proof valve 11 .

[0066] First, this embodiment further defines the structure of the battery pack case 10, which adopts a double-layer sidewall structure, specifically including an inner wall 13 and an outer wall 12. The inner wall 13 forms a space for accommodating the core pack 16, and a fire extinguishing agent interlayer 14 is constructed between the inner wall 13 and the outer wall 12. More specifically, the inner wall 13 of the battery pack case 10 of this embodiment is a 6061 aluminum structure with a sealed pressure bearing capacity greater than 7 MPa, and the fire extinguishing agent interlayer 14 is formed by welding. Its pressure bearing capacity greater than 7 MPa ensures that the fire extinguishing agent will not leak.

[0067] Furthermore, perfluorohexanone is used as the fire extinguishing agent in this embodiment. A fire extinguishing agent loading port 1401 is machined at the junction of the outer wall 12 of the housing and the fire extinguishing agent interlayer 14. This port allows for the addition of fire extinguishing agent and the sealing effect of nitrogen pressure injection. The specific filling requirements within the fire extinguishing agent interlayer 14 of this embodiment are: 80%-85% of the space within the fire extinguishing agent interlayer 14 is used for fire extinguishing agent. Furthermore, after the fire extinguishing agent is added, 2.5MPa-3.0MPa of nitrogen is added to the interior of the fire extinguishing agent interlayer 14 to serve as the driving force for the fire extinguishing agent injection.

[0068] More preferably, the groove 15 of this embodiment is separated from the fire extinguishing agent interlayer 14 by a structural wall, and a fire extinguishing agent pressure relief port 101 is provided on the structural wall; one end of the fire extinguishing agent pressure relief port 101 communicating with the fire extinguishing agent interlayer 14 is connected to a bursting disc 102 of a fire extinguishing device; and the end of the fire extinguishing agent pressure relief port 101 cooperating with the detonating assembly 2 is in an open state;

[0069] The inner wall 13 of the battery pack box 10 is provided with a fire extinguishing agent box internal discharge port 1402. The fire extinguishing agent discharged from the fire extinguishing agent pressure relief port 101 enters the accommodating space of the core pack 16 through the fire extinguishing agent box internal discharge port 1402.

[0070] The detonation assembly 2 is provided with a fire extinguishing agent explosion-proof valve discharge port 1403 , and the fire extinguishing agent discharged from the fire extinguishing agent pressure relief port 102 enters the tank 15 through the fire extinguishing agent explosion-proof valve discharge port 1403 .

[0071] At the same time, the discharge port 1402 in the fire extinguishing agent box and the discharge port 1403 of the fire extinguishing agent explosion-proof valve in this embodiment are both configured as conical discharge ports;

[0072] The conical discharge port is configured as a structure with an inner diameter gradually decreasing from the fire extinguishing agent inlet end to the fire extinguishing agent discharge end.

[0073] This embodiment further defines the structure of the fire extinguishing device 1, which seals the fire extinguishing agent interlayer 14 through a structural wall between the fire extinguishing agent interlayer 14 and the aforementioned groove 15, while also providing a foundation for the installation of the fire extinguishing device. First, a fire extinguishing agent pressure relief port 101 is machined in the structural wall. Simultaneously, a fire extinguishing device bursting diaphragm 102 is used to seal the fire extinguishing agent pressure relief port 101 located at one end inside the fire extinguishing agent interlayer 14. Simultaneously, an ignition assembly 2 is installed in the groove, and the ignition end of the ignition assembly 2 extends into the fire extinguishing agent pressure relief port 101, thereby destroying the fire extinguishing device bursting diaphragm 102 in the ignition state, thereby releasing the fire extinguishing agent in the fire extinguishing agent interlayer 14. The fire extinguishing agent is then discharged to the vicinity of the core package 16 and the explosion-proof valve 11 through the aforementioned discharge port 1402 in the fire extinguishing agent box and the discharge port 1403 in the fire extinguishing agent explosion-proof valve, respectively, thereby suppressing the fire in the core package 16 and the explosion-proof valve 11 through the fire extinguishing agent.

[0074] Preferably, the discharge port 1402 inside the fire extinguishing agent box and the discharge port 1403 of the fire extinguishing agent explosion-proof valve in this embodiment are both conical discharge ports; such a design can facilitate the rapid atomization of the fire extinguishing agent, thereby playing the role of cooling and extinguishing the fire. At the same time, the small diameter of the conical port can extend the discharge time of the fire extinguishing agent, thereby achieving the effect of suppressing the fire for a long time.

[0075] Preferably, the detonating assembly 2 of this embodiment includes an outer detonating assembly body 201 installed in the groove 15 and with a certain gap reserved between it and the fire extinguishing agent pressure relief port 101; an inner detonating assembly body 202 installed at the center of the outer detonating assembly body 201, and an air guide tube 203 protruding from one end of the inner detonating assembly body 202 near the fire extinguishing agent pressure relief port 101, and the air guide tube 203 partially extends into the fire extinguishing agent pressure relief port 101; and a trigger structure designed in this embodiment;

[0076] The trigger structure of this embodiment includes:

[0077] A trigger chamber is installed in the internal body 202 of the detonator assembly, and there is an ignition powder 206 inside the trigger chamber. A conductor 204 and a resistance wire 205 connected to the conductor 204 are installed at one end of the trigger chamber relative to the ignition powder 206. The conductor 204 is energized and heats the resistance wire 205 to ignite the ignition powder 206 through the resistance wire 205; a trigger structure bursting membrane 207 is provided at the end of the trigger chamber.

[0078] This embodiment further defines the structure of the detonating assembly 2, which is installed near the explosion-proof valve 11. The ignition powder 206 in the detonating assembly 2 of this embodiment is mainly composed of 165 mg of potassium zirconium perchlorate. At the same time, the resistance wire 205 is connected to the conductor 204 by welding. The material of the conductor 204 is generally a copper wire with a diameter of 2 mm. When the conductor 204 receives a current of 1.75 A with a duration of >100 ms, the resistance wire 205 generates ohmic heat, heating the ignition powder 206. At this time, the ignition powder 206 produces a violent chemical reaction, generating huge pressure and shock waves. When the trigger device bursting diaphragm 207 is broken by the shock wave, it continues to be transmitted along the above-mentioned air guide tube 203 to the fire extinguishing device bursting diaphragm 102. As a preferred embodiment, the diameter of the air guide tube 203 in this embodiment is 2 mm, and the distance from the fire extinguishing device bursting diaphragm 102 is 5 mm-10 mm. The pressure of the air guide tube 203 in this embodiment is generally greater than 10 MPa. The impact force will continue to break through the fire extinguishing device bursting diaphragm 102, thereby releasing the fire extinguishing agent from the fire extinguishing agent interlayer 14.

[0079] This embodiment further defines the structure of the detonating assembly 2.

[0080] Preferably, the fire extinguishing device bursting disk 102 and the trigger structure bursting disk 207 of this embodiment are both made of aluminum bursting disks with a bearing pressure of 4MPa-5MPa;

[0081] The present invention further discloses a battery pack, wherein the fire extinguishing device 1 as described above is integrated into a battery pack box of the battery pack.

[0082] The present invention further discloses a car, which is a new energy car and is integrated with the battery pack described above.

[0083] Preferably, when the core pack 16 in the battery pack of the automobile undergoes thermal runaway and drives the internal pressure of the battery pack to increase, the explosion-proof valve 11 opens and releases pressure, and the automobile transmits an alarm signal to the BMS. The BMS emits a current of 1.75A with a duration greater than 100ms through the thermal runaway alarm strategy, and transmits the current to the conductor 204 to drive the resistance wire 205 to generate resistive ohmic heat to ignite the ignition powder 206.

[0084] The more specific working principle and process of the device of this embodiment are as follows:

[0085] When the battery cell experiences thermal runaway, the high-temperature solids, liquids, and gases it produces increase the internal pressure of the battery pack. When the pressure rises to 5kPa, the explosion-proof valve 11 opens to release the pressure. When the explosion-proof valve 11 opens, it transmits an alarm signal to the BMS. At this time, the BMS uses the thermal runaway alarm strategy to send a current of 1.75A with a duration of >100ms to the resistance wire 205 of the ignition component. The resistance wire 205 generates a large amount of resistance ohmic heat. When the resistance wire 205 generates enough heat, it will ignite the internal ignition powder 206. Subsequently, when the ignition powder 206 is ignited and a chemical reaction occurs, huge pressure and shock waves are generated. This pressure and shock wave will break through the trigger device bursting diaphragm 207. This pressure and shock wave continue to be transmitted along the air duct 203 to the fire extinguishing device bursting diaphragm 102 and break it.

[0086] Subsequently, when the bursting diaphragm 102 of the fire extinguishing device is opened, the fire extinguishing agent is released and enters the groove 15. Since the fire extinguishing agent interlayer 14 is in a high-pressure state, due to the pressure difference, the fire extinguishing agent will be released into the battery pack and the explosion-proof valve 11 through the discharge port 1402 in the fire extinguishing agent box and the discharge port 1403 of the fire extinguishing agent explosion-proof valve respectively. At the same time, since the discharge ports are all conical discharge ports and the outlet end diameter is small, the fire extinguishing agent discharge time can be extended to achieve the effect of suppressing the fire for a long time.

[0087] Perfluoroacetone can easily vaporize at 49°C, thereby cooling the surrounding temperature and blocking the combustion chain, thereby effectively avoiding the uncontrollable heat spread caused by the fire of the explosion-proof valve.

[0088] In the above technical solution, the present invention provides a structure for preventing fire of a battery pack thermal runaway explosion-proof valve, which has the following beneficial effects:

[0089] The present invention provides a structure for preventing a battery pack explosion-proof valve from catching fire due to thermal runaway, as well as a battery pack and a new energy vehicle having the structure. The structure can effectively and quickly reduce the temperature of a battery pack in thermal runaway, and at the same time, suppress the fire and combustion of the battery pack caused by thermal runaway for a long time, thereby preventing more serious heat diffusion of the entire pack and further ensuring the safety of the entire vehicle and the passenger compartment.

[0090] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A structure for preventing fire from a battery pack explosion-proof valve caused by thermal runaway, characterized in that: The structure is a fire extinguishing device (1), wherein an explosion-proof valve (11) is integrated at the end of the battery pack box (10), and the fire extinguishing device (1) is arranged at a position close to the explosion-proof valve (11); The fire extinguishing device (1) is configured as a structure for suppressing fires in the core package (16) and the explosion-proof valve (11) by using a fire extinguishing agent; The battery pack box (10) has a fire extinguishing agent interlayer (14), and the fire extinguishing agent interlayer (14) stores the fire extinguishing agent; The fire extinguishing agent interlayer (14) has a fire extinguishing agent pressure relief port (101), and the fire extinguishing agent pressure relief port (101) is sealed by a fire extinguishing device bursting disc (102); The fire extinguishing device (1) has an ignition assembly (2), which is used to destroy the rupture diaphragm (102) of the fire extinguishing device when the core package (16) thermally runs away, thereby releasing the fire extinguishing agent in the fire extinguishing agent interlayer (14) and guiding the fire extinguishing agent to the core package (16) and the explosion-proof valve (11).

2. The structure for preventing fire of a battery pack thermal runaway explosion-proof valve according to claim 1, characterized in that: The battery pack box (10) is divided into a box inner wall (13) and a box outer wall (12); The space inside the inner wall (13) of the box is a space for accommodating the core package (16); The space between the inner wall (13) of the box and the outer wall (12) of the box is a fire extinguishing agent interlayer (14) surrounding the battery pack box (10); The position of the battery pack case (10) where the explosion-proof valve (11) is installed has a groove (15) extending along the corresponding edge of the battery pack case (10), and the detonation assembly (2) is arranged at the end of the groove (15) close to the explosion-proof valve (11).

3. The structure for preventing fire of a battery pack thermal runaway explosion-proof valve according to claim 1, characterized in that: The groove (15) and the fire extinguishing agent interlayer (14) are isolated by a structural wall, and the fire extinguishing agent pressure relief port (101) is provided on the structural wall; One end of the fire extinguishing agent pressure relief port (101) communicating with the fire extinguishing agent interlayer (14) is connected to the fire extinguishing device bursting disc (102); The fire extinguishing agent pressure relief port (101) is in an open state at one end in cooperation with the detonation assembly (2); The inner wall (13) of the battery pack box (10) is provided with a fire extinguishing agent box internal discharge port (1402), and the fire extinguishing agent discharged from the fire extinguishing agent pressure relief port (101) enters the accommodating space of the core pack (16) through the fire extinguishing agent box internal discharge port (1402); The detonation assembly (2) is provided with a fire extinguishing agent explosion-proof valve discharge port (1403), and the fire extinguishing agent discharged from the fire extinguishing agent pressure relief port (101) enters the tank (15) through the fire extinguishing agent explosion-proof valve discharge port (1403).

4. The structure for preventing fire of a battery pack thermal runaway explosion-proof valve according to claim 3, characterized in that: The fire extinguishing agent box internal discharge port (1402) and the fire extinguishing agent explosion-proof valve discharge port (1403) are both configured as conical discharge ports; The conical discharge port is configured as a structure with an inner diameter gradually decreasing from the fire extinguishing agent inlet end to the fire extinguishing agent discharge end.

5. The structure for preventing fire of a battery pack thermal runaway explosion-proof valve according to claim 3, characterized in that: The detonation assembly (2) comprises: An outer body (201) of the detonating assembly is installed in the groove (15) and has a certain gap between it and the fire extinguishing agent pressure relief port (101); An internal body (202) of the detonating assembly is installed at the center of the external body (201) of the detonating assembly, and an air guide tube (203) is formed on one end of the internal body (202) of the detonating assembly close to the fire extinguishing agent pressure relief port (101), and a portion of the air guide tube (203) extends into the fire extinguishing agent pressure relief port (101); and trigger structure; The trigger structure includes: A trigger chamber is installed in the internal body (202) of the detonation component, and the trigger chamber has ignition powder (206) inside. The trigger chamber is installed with a conductor (204) and a resistance wire (205) connected to the conductor (204) at one end relative to the ignition powder (206). The conductor (204) is energized and heats the resistance wire (205) to ignite the ignition powder (206) through the resistance wire (205); A trigger structure bursting disc (207) is provided at the end of the trigger cavity.

6. The structure for preventing fire of a battery pack thermal runaway explosion-proof valve according to claim 5, characterized in that: The fire extinguishing device bursting disk (102) and the trigger structure bursting disk (207) are both aluminum bursting disks with a bearing pressure of 4MPa-5MPa; The inner wall (13) of the battery pack box (10) is a 6061 series aluminum structure with a sealing pressure bearing capacity greater than 7 MPa.

7. The structure for preventing fire of a battery pack explosion-proof valve due to thermal runaway according to claim 5, characterized in that: The ignition powder (206) is 165 mg of potassium zirconium perchlorate; The conductor (204) is copper with a diameter of 2 mm, and the resistance wire (205) is welded to the conductor (204); The fire extinguishing agent is perfluorohexanone fire extinguishing agent.

8. A battery pack, characterized in that The battery pack case of the battery pack is integrated with a fire extinguishing device (1) according to any one of claims 1 to 7.

9. Automobile, wherein the automobile is a new energy vehicle, characterized in that: The vehicle is integrated with the battery pack as claimed in claim 8.

10. The automobile according to claim 9, characterized in that When the core pack (16) in the battery pack of the automobile experiences thermal runaway and drives the internal pressure of the battery pack to increase, the explosion-proof valve (11) opens and releases pressure, and the automobile transmits an alarm signal to the BMS. The BMS issues a current of 1.75A with a duration greater than 100ms through a thermal runaway alarm strategy, and transmits the current to the conductor (204) to drive the resistance wire (205) to generate resistance ohmic heat for igniting the ignition powder (206).

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