Fireproof device of power battery and use method of fireproof device

Abstract

The invention discloses a fireproof device of a power battery and a use method thereof, and the fireproof device comprises a box body which is detachably connected with a cover plate; the passive fire extinguishing assembly is arranged on the inner side of the box body so as to convey a fire extinguishing agent when the battery is on fire; the active fire prevention assembly and the passive fire extinguishing assembly are arranged side by side so as to actively release a fire suppression gas to a battery; the shuttle valve is arranged at the output end of the passive fire extinguishing assembly, and the input end of the shuttle valve communicates with the active fire extinguishing assembly; by arranging the passive fire extinguishing assembly, the active fireproof assembly, the shuttle valve and the controller, the device can convey a combustion-supporting gas into the power battery box when no fire occurs, so that the combustion-supporting oxygen concentration is reduced, the occurrence probability of the fire in the power battery box is reduced, meanwhile, a fire extinguishing agent can be input in time to extinguish the fire when the fire occurs, and the fire extinguishing efficiency is improved. In addition, a sealing structure is arranged at the heat dissipation holes, so that the influence on electric parts inside the box body when a fire occurs on the periphery of the box body is avoided.

Description

Technical Field

[0001] The present invention specifically relates to a fire prevention device for a power battery and a method of using the same. Background Art

[0002] The power battery box stores power batteries, which are mainly used in electric vehicles (EVs), hybrid electric vehicles (PHEVs) and other electric equipment.

[0003] Existing power battery boxes are usually equipped with passive fire extinguishing devices. That is, when a fire occurs inside the power battery box, the fire extinguishing device promptly delivers fire extinguishing agent to the inside of the battery box to extinguish the fire. However, after the fire occurs, the inside of the power battery box will still be damaged, and the subsequent maintenance cost is high. It cannot reduce the fire risk caused by thermal runaway of the lithium battery when there is no fire. For this reason, we propose a fire prevention device for power batteries and a method of using it. Summary of the Invention

[0004] The object of the present invention is to provide a fire prevention device for a power battery and a method of using the same, so as to solve the problems raised in the above background technology.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a fire prevention device for a power battery, comprising:

[0006] A box body, to which a cover plate is detachably connected;

[0007] a passive fire extinguishing assembly disposed inside the housing to deliver a fire extinguishing agent in the event of a battery fire;

[0008] an active fire protection component, arranged side by side with the passive fire extinguishing component to actively release a flame-suppressing gas toward the battery;

[0009] A shuttle valve is provided at the output end of the passive fire extinguishing component, and the input end of the shuttle valve is connected to the active fire protection component, and the output end of the shuttle valve is connected to the fire protection access end on the outer wall of the box body through a pipeline;

[0010] The controller is arranged at the inner edge of the box body, and the controller is electrically connected to the passive fire extinguishing component and the active fire protection component through a wiring harness.

[0011] Preferably, the active fire protection component includes a molecular sieve, a gas heating tube, a pressure reducing valve, a filter control valve and a gas tank control valve. The gas heating tube is fixed to the upper end of the inner side of the box body through a support plate, and one end of the gas heating tube is provided with a first interface connected to the external air filter, and the other end of the gas heating tube is connected to the molecular sieve, the first output end of the molecular sieve is connected to the external gas tank, and the second output end of the molecular sieve is connected to the pressure reducing valve and the gas tank control valve in sequence, the filter control valve is arranged at the lower end of the inner side of the box body, and the two ends of the filter control valve are respectively connected to the external air compressor and the air filter.

[0012] Preferably, the active fire protection component also includes an oxygen module and an exhaust valve. The oxygen module is fixed to one end of the inner side of the box body, and an output pipe is provided on one side of the oxygen module. One end of the output pipe is connected to the exhaust valve, and one end of the exhaust valve is connected to the exhaust end provided on a side wall of the box body.

[0013] Preferably, the first input end of the shuttle valve is provided with a second pipeline connected to the output pipe, and the second input end of the shuttle valve is provided with a first pipeline connected to the passive fire extinguishing component.

[0014] Preferably, the molecular sieve is tubular, and the molecular sieve is a carbon molecular sieve.

[0015] Preferably, the passive fire extinguishing component includes a perfluorohexanone fire extinguishing agent, a support and a connecting hole. A gas generating component for pushing the fire extinguishing agent out is provided at one end of the inner side of the perfluorohexanone fire extinguishing agent, supports are provided at both ends of the outer surface of the perfluorohexanone fire extinguishing agent, and a connecting hole is provided on the inner side of the lower end of the support. A bracket is fixed to the bottom end of the inner side of the box body, and a mounting screw hole corresponding to the connecting hole is provided on the bracket. A positioning plate that cooperates with the bracket is fixed to the side wall of the lower end of the support.

[0016] Preferably, a heat dissipation hole is provided through the inner side of the cover plate, and a sealing structure for closing the heat dissipation hole in case of fire is provided on the lower surface of the cover plate.

[0017] Preferably, the sealing structure includes a fixed block, a slider, a deformable part, a guide rail, a sealing plate and a torsion spring. The guide rail is fixed to the lower surface of the cover plate, and a sealing plate is slidably connected to the inner side of the guide rail. A slider that slides with the cover plate is fixed to the sealing plate. The fixed block is fixed to the upper surface of the cover plate, and a deformable part that deforms due to temperature is provided between the fixed block and the slider. A torsion spring is provided at one end of the sealing plate to push it to move, and the other end of the torsion spring is in conflict with the protrusion on the lower surface of the cover plate.

[0018] Preferably, the deformable member is made of memory alloy or thermosensitive glass ball.

[0019] A method for using a power battery fire prevention device, comprising the following steps:

[0020] Step A: The external air compressor and air filter are connected to both ends of the filter control valve, and the input end of the gas heating pipe is connected to the air filter. The filter control valve is then opened to allow the compressed air to flow into the gas heating pipe after being filtered and heated. The combustion suppression gas is then separated by the molecular sieve and passed to the pressure reducing valve and the external gas storage tank.

[0021] Step B: The flame-suppressing gas passing through the pressure reducing valve flows into the oxygen module through the gas storage tank control valve. After being tested and qualified by the oxygen module, it flows into the shuttle valve and is connected to the power battery box through the fireproof access terminal at the output end of the shuttle valve to provide flame-suppressing gas into the battery box, thereby reducing the oxygen concentration in the power battery box and reducing the risk of fire in the power battery box.

[0022] Step C: When insufficient combustion suppression gas is detected at the shuttle valve, the combustion suppression gas in the gas storage tank flows into the pressure reducing valve and is then transported to the power battery box through the shuttle valve;

[0023] Step D: When a fire occurs in the power battery box, the controller activates the gas generating assembly inside the perfluoroacetic acid fire extinguishing agent to generate gas, pushing the piston inside the perfluoroacetic acid fire extinguishing agent to move so as to push the fire extinguishing agent into the first pipe. The pressure inside the first pipe is higher than that in the second pipe. The fire extinguishing agent flows into the power battery box through the fireproof access port at the output end of the shuttle valve to extinguish the fire.

[0024] Step E: When a fire occurs unexpectedly around the box, the fire temperature will cause the deformable member to deform. At this time, the sealing plate is pushed by the elastic force of the torsion spring to move to the heat dissipation hole and close the heat dissipation hole.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention is provided with a passive fire extinguishing component, an active fire protection component, a shuttle valve and a controller, thereby avoiding the traditional power battery box that can only perform passive fire extinguishing when a fire occurs. When there is no fire, the present device can transport flame-suppressing gas into the power battery box to reduce the concentration of oxygen that supports combustion, reduce the probability of fire in the power battery box, and perform active fire protection. At the same time, when a fire occurs, the fire extinguishing agent can be input in time to extinguish the fire. The combination of passive and active methods is used to improve the fire protection effect of the power battery box, thereby increasing the practicality of the device. By providing a sealing structure at the heat dissipation hole, the fire around the box is prevented from affecting the electrical components inside the box. The present structure can quickly seal the heat dissipation hole, improve the effect of isolating external flames, and ensure good fire protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the present invention;

[0028] Figure 2This is a schematic structural diagram of the active fire extinguishing assembly of the present invention;

[0029] Figure 3 Schematic diagram of the molecular sieve structure of the present invention;

[0030] Figure 4 It is a schematic diagram of the shuttle valve structure of the present invention;

[0031] Figure 5 This is a schematic structural diagram of the passive fire extinguishing assembly of the present invention;

[0032] Figure 6 It is a schematic diagram of the support structure of the present invention;

[0033] Figure 7 Schematic diagram of the sealing structure of the present invention;

[0034] Figure 8 Schematic diagram of the guide rail structure of the present invention;

[0035] Figure 9 Schematic diagram of the torsion spring structure of the present invention;

[0036] Figure 10 The figure is a flow chart of the method for using the present invention.

[0037] In the figure: 1. Box body; 2. Cover plate; 3. Exhaust end; 5. Fire protection access end; 6. Passive fire extinguishing component; 601. Perfluorohexanone fire extinguishing agent; 602. Support; 603. Connection hole; 604. Positioning plate; 7. Active fire protection component; 701. Molecular sieve; 702. Gas heating pipe; 703. Pressure reducing valve; 704. Filter control valve; 705. Oxygen module; 706. Exhaust valve; 707. Gas tank control valve; 8. Shuttle valve; 9. Controller; 10. Heat dissipation hole; 11. First pipeline; 12. Second pipeline; 131. Fixed block; 132. Slider; 133. Deformable part; 134. Guide rail; 135. Sealing plate; 136. Torsion spring. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] See also Figures 1-10 The present invention provides a technical solution: a fire prevention device for a power battery, comprising:

[0040] A box body 1, to which a cover plate 2 is detachably connected;

[0041] a passive fire extinguishing assembly 6 , which is arranged inside the housing 1 to deliver a fire extinguishing agent in the event of a battery fire;

[0042] It is convenient to timely deliver fire extinguishing agent to extinguish fire when it occurs inside the power battery box;

[0043] An active fire protection component 7 is arranged side by side with the passive fire extinguishing component 6 to actively release a flame-suppressing gas to the battery;

[0044] It is convenient to transport the flame-suppressing gas into the power battery box when there is no fire, so as to reduce the oxygen content in the air inside the power battery box, thereby isolating the oxygen that supports combustion. The flame-suppressing gas is an inert gas, preferably nitrogen;

[0045] Nitrogen is used to replace the air and fill the space where the lithium battery is located, so that the lithium battery is in an oxygen-free, low-humidity inert environment, reducing the conditions for thermal runaway of the lithium battery. Even if thermal runaway occurs, it will not affect adjacent batteries, reducing the probability of battery combustion and explosion.

[0046] The shuttle valve 8 is provided at the output end of the passive fire extinguishing component 6, and the input end of the shuttle valve 8 is connected to the active fire protection component 7, and the output end of the shuttle valve 8 is connected to the fire protection access end 5 on the outer wall of the box body 1 through a pipeline;

[0047] It is convenient to deliver the fire extinguishing agent or the combustion suppressant gas to the power battery box separately. The shuttle valve 8 is a straight-stroke valve with a valve body and an actuator integrated into one. It has the advantages of small size and easy installation.

[0048] The controller 9 is arranged on the inner edge of the box body 1, and the controller 9 is electrically connected to the passive fire extinguishing component 6 and the active fire protection component 7 through a wiring harness;

[0049] It is convenient to control the delivery of the flame-suppressing gas or the passive fire extinguishing component 6 to work to deliver the fire extinguishing agent.

[0050] Preferably, the active fire protection component 7 includes a molecular sieve 701, a gas heating pipe 702, a pressure reducing valve 703, a filter control valve 704 and a gas tank control valve 707. The gas heating pipe 702 is fixed to the upper end of the inner side of the box body 1 through a support plate, and one end of the gas heating pipe 702 is provided with a first interface connected to an external air filter, and the other end of the gas heating pipe 702 is connected to the molecular sieve 701, the first output end of the molecular sieve 701 is connected to the external gas tank, and the second output end of the molecular sieve 701 is connected to the pressure reducing valve 703 and the gas tank control valve 707 in sequence, the filter control valve 704 is provided at the lower end of the inner side of the box body 1, and the two ends of the filter control valve 704 are respectively connected to the external air compressor and the air filter;

[0051] It is convenient to produce flame-suppressing gas through air. The flame-suppressing gas is nitrogen, which can be transported to the inside of the power battery box to reduce the oxygen content inside the power battery box that supports combustion and reduce fire.

[0052] Preferably, the active fire protection assembly 7 further includes an oxygen module 705 and an exhaust valve 706. The oxygen module 705 is fixed to one end of the inner side of the box body 1, and an output pipe is provided on one side of the oxygen module 705. One end of the output pipe is connected to the exhaust valve 706, and one end of the exhaust valve 706 is connected to the exhaust port 3 provided on a side wall of the box body 1.

[0053] It is convenient to detect the oxygen concentration in the produced nitrogen through the oxygen module 705, so as to facilitate the subsequent delivery of nitrogen of appropriate concentration to the power battery box and discharge of unqualified nitrogen. At the same time, it can also discharge nitrogen with a large content.

[0054] Preferably, the first input end of the shuttle valve 8 is provided with a second pipe 12 connected to the output pipe, and the second input end of the shuttle valve 8 is provided with a first pipe 11 connected to the passive fire extinguishing component 6 .

[0055] Preferably, the molecular sieve 701 is tubular, and the molecular sieve 701 is a carbon molecular sieve;

[0056] Molecular sieve separation technology PSA uses the preferential adsorption characteristics of carbon molecular sieves for oxygen to separate nitrogen. Under high pressure, oxygen is adsorbed and nitrogen passes directly. Compared with molecular membranes, molecular sieves are cheaper.

[0057] Preferably, the passive fire extinguishing assembly 6 includes a perfluoroacetic acid ketone fire extinguishing agent 601, a support 602 and a connecting hole 603. A gas generating assembly for promoting the ejection of the fire extinguishing agent is provided at one end of the inner side of the perfluoroacetic acid ketone fire extinguishing agent 601. Supports 602 are provided at both ends of the outer surface of the perfluoroacetic acid ketone fire extinguishing agent 601, and a connecting hole 603 is provided on the inner side of the lower end of the support 602. A bracket is fixed to the bottom end of the inner side of the box body 1, and a mounting screw hole corresponding to the connecting hole 603 is provided on the bracket. A positioning plate 604 that cooperates with the bracket is fixed to the side wall of the lower end of the support 602.

[0058] The high-pressure gas generated by triggering the gas generating assembly drives the piston, which pushes the fire extinguishing agent out to extinguish the fire outside. The support 602 facilitates installation, and the expired or used perfluorohexanone fire extinguishing agent 601 can be easily replaced later.

[0059] Preferably, a heat dissipation hole 10 is opened through the inner side of the cover plate 2, and a sealing structure is provided on the lower surface of the cover plate 2 to close the heat dissipation hole 10 in case of fire, so as to avoid closing the heat dissipation hole 10 in case of fire, thereby isolating the outside world from the connection with the inside of the box body 1 and reducing the impact of the fire.

[0060] Preferably, the sealing structure includes a fixed block 131, a slider 132, a deformable member 133, a guide rail 134, a sealing plate 135, and a torsion spring 136. The guide rail 134 is fixed to the lower surface of the cover plate 2, and the sealing plate 135 is slidably connected to the inner side of the guide rail 134. The sealing plate 135 is fixed with a slider 132 that slides with the cover plate 2. The fixed block 131 is fixed to the upper surface of the cover plate 2, and a deformable member 133 that deforms under the influence of temperature is provided between the fixed block 131 and the slider 132. A torsion spring 136 is provided at one end of the sealing plate 135 to push it to move, and the other end of the torsion spring 136 contacts the protrusion on the lower surface of the cover plate 2.

[0061] When a fire occurs, the deformable member 133 is deformed or broken by the high temperature of the fire, so that the torsion spring 136 pushes the sealing plate 135 to move along the guide rail 134, and the sealing plate 135 corresponds to the heat dissipation hole 10 to seal it.

[0062] Preferably, the deformable member 133 is made of a memory alloy or a thermosensitive glass ball, so that it can be deformed or broken by heat, thereby releasing the limit of the slider 132 and allowing the sealing plate 135 to move.

[0063] A method for using a power battery fire prevention device, comprising the following steps:

[0064] Step A: An external air compressor and an air filter are connected to both ends of the filter control valve 704, and the input end of the gas heating pipe 702 is connected to the air filter. The filter control valve 704 is then opened to allow the compressed air to flow into the gas heating pipe 702 for heating. The compressed air is then separated by the molecular sieve 701 and passed to the pressure reducing valve 703 and the external gas storage tank.

[0065] Step B: The combustion-suppressing gas passing through the pressure reducing valve 703 flows into the oxygen module 705 through the gas storage tank control valve 707. After being tested and qualified by the oxygen module 705, it flows into the shuttle valve 8 and is connected to the power battery box through the fire protection access terminal 5 at the output end of the shuttle valve 8. This provides the combustion-suppressing gas to the battery box, reduces the oxygen concentration in the power battery box, and reduces the risk of fire in the power battery box.

[0066] Step C: When the amount of the combustion suppressing gas is detected to be insufficient at the shuttle valve 8, the combustion suppressing gas in the gas storage tank flows into the pressure reducing valve 703 and then is delivered to the power battery box through the shuttle valve 8;

[0067] Step D: When a fire occurs in the power battery box, the controller 9 activates the gas generating assembly inside the perfluoroacetic acid extinguishing agent 601 to generate gas, pushing the piston inside the perfluoroacetic acid extinguishing agent 601 to move and push the fire extinguishing agent into the first pipe 11. The pressure inside the first pipe 11 is higher than that in the second pipe 12. The fire extinguishing agent flows into the power battery box through the fire protection access port 5 at the output end of the shuttle valve 8 to extinguish the fire.

[0068] Step E: When a fire breaks out accidentally around the box body 1, the fire temperature will cause the deformation part 133 to deform. At this time, the sealing plate 135 is pushed by the elastic force of the torsion spring 136 to move to the heat dissipation hole 10 to close the heat dissipation hole 10.

[0069] The flame-inhibiting gas of the present invention is nitrogen. The control strategy during fire prevention is divided into three parts: nitrogen production, nitrogen filling of the battery box, and cooling and extinguishing.

[0070] 1. Nitrogen production control:

[0071] When the pressure P1 of the nitrogen gas storage tank < Pa, open the compressed air solenoid valve to produce nitrogen until P1 > Pb.

[0072] P1 is the gas pressure of the nitrogen gas storage tank, Pa is the pressure threshold of the storage tank when nitrogen production starts, and Pb is the pressure threshold of the storage tank when nitrogen production stops.

[0073] 2. Nitrogen filling control of the battery box:

[0074] When the pressure P2 of the battery box < Pc, open the solenoid valve of the gas storage tank, detect the nitrogen and oxygen concentration C and humidity H. If it meets the standards, fill nitrogen until P2 > Pd.

[0075] P2 is the internal gas pressure of the battery box, Pc is the pressure threshold of the battery box when nitrogen filling starts, and Pd is the pressure threshold of the battery box when nitrogen filling stops.

[0076] 3. Cooling and extinguishing control:

[0077] When the temperature T of the battery box > Tm or smoke is detected, inject fire extinguishing agent into the battery box to cool down.

[0078] T is the internal temperature of the battery box, and Tm is the preset internal temperature threshold of the battery box.

[0079] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fire protection device for a power battery, characterized in that: include: A box body (1), wherein a cover plate (2) is detachably connected to the box body (1); A passive fire extinguishing assembly (6) is arranged inside the box (1) to deliver a fire extinguishing agent when a battery fire occurs; an active fire protection component (7) arranged side by side with the passive fire extinguishing component (6) to actively release a flame-suppressing gas to the battery; A shuttle valve (8) is provided at the output end of the passive fire extinguishing component (6), and the input end of the shuttle valve (8) is connected to the active fire protection component (7), and the output end of the shuttle valve (8) is connected to the fire protection access end (5) on the outer wall of the box (1) through a pipeline; The controller (9) is arranged on the inner edge of the box (1), and the controller (9) is electrically connected to the passive fire extinguishing component (6) and the active fire protection component (7) through a wiring harness.

2. A fire protection device for a power battery according to claim 1, characterized in that: The active fire protection component (7) comprises a molecular sieve (701), a gas heating pipe (702), a pressure reducing valve (703), a filter control valve (704) and a gas storage tank control valve (707); the gas heating pipe (702) is fixed to the upper end of the inner side of the box (1) through a support plate, and one end of the gas heating pipe (702) is provided with a first interface connected to an external air filter, and the other end of the gas heating pipe (702) is connected to the molecular sieve (701); the first output end of the molecular sieve (701) is connected to the external gas storage tank, and the second output end of the molecular sieve (701) is connected to the pressure reducing valve (703) and the gas storage tank control valve (707) in sequence; the filter control valve (704) is provided at the lower end of the inner side of the box (1), and the two ends of the filter control valve (704) are respectively connected to the external air compressor and the air filter.

3. A fire protection device for a power battery according to claim 2, characterized in that: The active fire protection component (7) further includes an oxygen module (705) and an exhaust valve (706), wherein the oxygen module (705) is fixed to one end of the inner side of the box body (1), and an output pipe is provided on one side of the oxygen module (705), and one end of the output pipe is connected to the exhaust valve (706), and one end of the exhaust valve (706) is connected to the exhaust end (3) provided on a side wall of the box body (1).

4. A fire protection device for a power battery according to claim 3, characterized in that: The first input end of the shuttle valve (8) is provided with a second pipe (12) connected to the output pipe, and the second input end of the shuttle valve (8) is provided with a first pipe (11) connected to the passive fire extinguishing component (6).

5. The fire protection device for a power battery according to claim 2, characterized in that: The molecular sieve (701) is tubular, and the molecular sieve (701) is a carbon molecular sieve.

6. The fire protection device for a power battery according to claim 1, characterized in that: The passive fire extinguishing assembly (6) comprises a perfluorohexanone fire extinguishing agent (601), a support (602) and a connecting hole (603); a gas generating assembly for pushing the fire extinguishing agent to be ejected is provided at one end of the inner side of the perfluorohexanone fire extinguishing agent (601); supports (602) are provided at both ends of the outer surface of the perfluorohexanone fire extinguishing agent (601); a connecting hole (603) is provided on the inner side of the lower end of the support (602); a bracket is fixed to the bottom end of the inner side of the box (1); and a mounting screw hole corresponding to the connecting hole (603) is provided on the bracket; and a positioning plate (604) cooperating with the bracket is fixed to the side wall of the lower end of the support (602).

7. The fire protection device for a power battery according to claim 1, characterized in that: A heat dissipation hole (10) is provided through the inner side of the cover plate (2), and a sealing structure for closing the heat dissipation hole (10) in the event of a fire is provided on the lower surface of the cover plate (2).

8. The fire protection device for a power battery according to claim 7, characterized in that: The sealing structure comprises a fixed block (131), a slider (132), a deformable member (133), a guide rail (134), a sealing plate (135) and a torsion spring (136); the guide rail (134) is fixed to the lower surface of the cover plate (2), and the inner side of the guide rail (134) is slidably connected to the sealing plate (135); the sealing plate (135) is fixed with a slider (132) that slidably cooperates with the cover plate (2); the fixed block (131) is fixed to the upper surface of the cover plate (2), and a deformable member (133) that deforms under the influence of temperature is provided between the fixed block (131) and the slider (132); one end of the sealing plate (135) is provided with a torsion spring (136) that pushes it to move, and the other end of the torsion spring (136) contacts the protrusion on the lower surface of the cover plate (2).

9. The fire protection device for a power battery according to claim 8, characterized in that: The material of the deformable member (133) is a memory alloy or a thermosensitive glass ball.

10. A method for using a power battery fire prevention device, characterized in that: The invention comprises applying the fire protection device according to any one of claims 1 to 9 and the following method: Step A: An external air compressor and an air filter are respectively connected to both ends of a filter control valve (704), and the input end of a gas heating pipe (702) is connected to the air filter. The filter control valve (704) is then opened to allow the compressed air to be filtered and flow into the inner side of the gas heating pipe (702) for heating. The combustion suppressing gas is then separated by a molecular sieve (701) and flows to a pressure reducing valve (703) and an external gas storage tank. Step B: The flame-suppressing gas passing through the pressure reducing valve (703) flows into the oxygen module (705) through the gas storage tank control valve (707), flows into the shuttle valve (8) after being tested by the oxygen module (705) and is connected to the power battery box through the fireproof access terminal (5) at the output end of the shuttle valve (8), so as to provide the flame-suppressing gas into the battery box, reduce the oxygen concentration in the power battery box, and reduce the fire in the power battery box; Step C: When insufficient amount of the combustion suppressing gas is detected at the shuttle valve (8), the combustion suppressing gas in the gas storage tank flows into the pressure reducing valve (703) and then is transported to the power battery box through the shuttle valve (8); Step D: When a fire occurs in the power battery box, the controller (9) activates the gas generating assembly inside the perfluorohexanone fire extinguishing agent (601) to generate gas, pushing the piston inside the perfluorohexanone fire extinguishing agent (601) to move so as to push the fire extinguishing agent into the inside of the first pipe (11). The pressure inside the first pipe (11) is higher than that in the second pipe (12). The fire extinguishing agent flows into the power battery box through the fireproof access end (5) at the output end of the shuttle valve (8) to extinguish the fire. Step E: When a fire occurs unexpectedly around the box (1), the fire temperature will cause the deformable member (133) to deform. At this time, the sealing plate (135) is pushed by the elastic force of the torsion spring (136) to move to the heat dissipation hole (10) and close the heat dissipation hole (10).

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