Intermittent spraying type liquid fire extinguishing apparatus having speed reducing mechanism, and method therefor

Abstract

An intermittent spraying type liquid fire extinguishing apparatus having a speed reducing mechanism, comprising a housing (1) and a gas-producing fire extinguishing agent (2) arranged in the housing (1). A front cover (3) is arranged on the front side of the housing (1), and a surface of the front cover (3) is provided with a nozzle (4). An end surface of the gas-producing fire extinguishing agent (2) is connected to one end of a starting component (5). A piston (7) in sliding fit with the housing (1) is disposed in the housing (1), and the piston (7) is connected to the bottom of the front cover (3) by means of a screw (6.1) of a ball screw rod mechanism (6). The top of the screw (6.1) is fixedly connected to the center of a rotating disc (8). A liquid fire extinguishing agent (12) is arranged between the piston (7) and the front cover (3). A spraying hole (9) is formed on a surface of the rotating disc (8). When the rotating disc (8) rotates, the spraying hole (9) and the nozzle (4) are periodically overlapped and staggered. Further disclosed is a fire extinguishing method for the intermittent spraying type liquid fire extinguishing apparatus having a speed reducing mechanism, so that an intermittent spraying process can be carried out continuously, to enable the pressure in a battery compartment to be periodically increased and decreased, a combustible gas inside a battery in the battery compartment can be completely discharged, and the risks of reburning is prevented.

Description

Intermittent spraying liquid fire extinguishing device and method with deceleration mechanism Technical Field

[0001] The present invention relates to the technical field of new energy battery fire extinguishing, and in particular to an intermittent spraying liquid fire extinguishing device and method with a deceleration mechanism. Background Art

[0002] When new energy batteries experience thermal runaway, they often continue to produce flammable gases. Traditional aerosol fire extinguishing devices are difficult to extinguish the flames instantly. Pulse fire extinguishing devices can extinguish the flames instantly but cannot achieve the effect of continuous suppression. When the pulse fire extinguishing device is used in combination with the traditional aerosol fire extinguishing device, the pulse fire extinguishing device can extinguish the flames generated instantly when the battery experiences thermal runaway, and the traditional aerosol fire extinguishing device can suppress the flames to a certain extent after the pulse fire extinguishing device is sprayed. Theoretically, the combination of the two overcomes each other's shortcomings, can extinguish the flames instantly and achieve the effect of continuous suppression; however, the following problems still exist. Taking the battery compartment where the battery is located as an example, when the battery experiences thermal runaway, a large amount of flammable gas escapes from the battery and enters the battery box At this time, after the fire extinguishing device is activated, due to the large gas production of the traditional aerosol fire extinguishing device, the aerosol fire extinguishing agent will quickly fill the entire battery box (that is, the battery compartment where the battery is located). In this process, only part of the flammable gas is pushed out of the battery compartment. More flammable gas is often pressed inside the battery and cannot be completely discharged due to the excessive positive pressure in the battery compartment when the aerosol fire extinguishing device is sprayed. Therefore, when the aerosol fire extinguishing device is completed, the pressure in the battery compartment drops, and a large amount of flammable gas escapes from the inside of the battery again, and there is still a risk of re-ignition; therefore, it is necessary to improve the traditional aerosol fire extinguishing device and design a fire extinguishing device that can spray continuously and intermittently, so that the pressure of the battery box increases and decreases periodically, thereby solving the above problems.

[0003] Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide an intermittent spraying liquid fire extinguishing device and method with a deceleration mechanism, which can continuously perform an intermittent spraying process, so that the pressure of the battery box increases and decreases periodically, which is conducive to the complete discharge of the combustible gas inside the battery in the battery box and prevents the risk of re-ignition.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solution: an intermittent spraying liquid fire extinguishing device with a deceleration mechanism, comprising a shell and a gas-generating fire extinguishing agent arranged in the shell, a front cover is provided on the front side of the shell, a nozzle is opened on the surface of the front cover, the end face of the gas-generating fire extinguishing agent is connected to one end of the starting component, a piston is provided in the shell and is slidably matched with the piston, the piston is connected to the bottom of the front cover through the screw of the ball screw mechanism, the top of the screw is fixedly connected to the center of the rotating disk through the deceleration mechanism, liquid fire extinguishing agent is provided between the piston and the front cover, a spray hole is opened on the surface of the rotating disk, and when the rotating disk rotates, the spray hole and the nozzle periodically overlap and intersect.

[0006] Preferably, the ball screw mechanism includes a nut fixed inside the piston, and the spiral groove area where the nut contacts the screw is filled with balls.

[0007] Preferably, the gas-generating fire extinguishing agent is a columnar structure formed by pressing aerosol generating agent powder, and the liquid fire extinguishing agent is perfluorohexanone fire extinguishing agent.

[0008] Preferably, the starting component is an electric ignition head or a thermal wire structure.

[0009] Preferably, the outer edge of the front cover is threadedly connected to the top of the shell, the bottom of the shell is threadedly connected to the outer edge of the rear cover, and the bottom of the screw is rotatably connected to the center of the rear cover through a bearing; the gas-generating fire extinguishing agent is located in the area where the rear cover is located, and a silicone layer is provided between the outer surface of the gas-generating fire extinguishing agent and the inner surface of the rear cover.

[0010] Preferably, a guide rail is vertically provided on the inner side of the shell, and a guide groove is provided on the outer side of the piston, and the guide groove is slidably matched with the guide rail.

[0011] Preferably, the reduction mechanism includes a central gear fixedly connected to the top of the screw, the central gear meshes with the inner sides of the three planetary gears, the radius of the central gear is smaller than the radius of the planetary gears, the outer sides of the planetary gears mesh with the inner sides of the fixed outer gear ring, the outer sides of the fixed outer gear ring are fixed to the inner side of the front cover, the top center of the rotating disk is rotationally connected to the front cover, and the top center of the planetary gears is rotationally connected to the bottom of the rotating disk.

[0012] Preferably, the top center axis of the rotating disk is rotationally connected to the front cover through a bearing, and the top center of the planetary gear is rotationally connected to the pin hole at the bottom of the rotating disk through a pin shaft.

[0013] Preferably, the three planetary gears are evenly distributed in a circular array with the central gear as the center, and three spray holes are opened on the surface of the rotating disk. The three spray holes are also evenly distributed in a circular array with the central gear as the center, and the three spray holes and the three planetary gears are staggered with each other.

[0014] In addition, the present invention also discloses a fire extinguishing method of the intermittent spraying liquid fire extinguishing device with a deceleration mechanism, which comprises the following steps:

[0015] S1: When thermal runaway occurs in the battery box, the starting component ignites the gas-generating fire extinguishing agent, which generates gas;

[0016] S2: The airflow pushes the piston to move to the position of the front cover, and the ball screw mechanism causes the screw to rotate;

[0017] S3: When the screw rotates, it is decelerated by the speed reduction mechanism, driving the rotating disk to rotate at a speed lower than the screw, so that the nozzle holes on the surface of the rotating disk and the nozzles on the surface of the front cover periodically overlap and intersect;

[0018] S4: When the nozzle hole and the nozzle outlet coincide, the liquid fire extinguishing agent is ejected from the nozzle. Under the action of the high temperature inside the battery box, it is converted into gas to extinguish the fire inside the battery box. When the nozzle hole and the nozzle outlet intersect, the shell is sealed and the pressure is held back. Finally, the above process is repeated periodically to realize the intermittent spraying process, so that the pressure inside the battery box increases and decreases periodically.

[0019] S5: When the pressure inside the battery box increases, the combustible gas diluted by the fire extinguishing material is pressed out from the gaps in the battery box. When the pressure inside the battery box decreases, the combustible gas inside the battery escapes and enters the battery box, and the above process is repeated.

[0020] Beneficial effects of the present invention:

[0021] In the present invention, the airflow pushes the piston to move toward the position of the front cover, and the ball screw mechanism causes the screw to rotate; when the screw rotates, it drives the rotating disk to rotate, so that the spray holes on the surface of the rotating disk and the nozzles on the surface of the front cover periodically overlap and intersect, so that the liquid fire extinguishing agent can continue to perform an intermittent spraying process, so that the pressure of the battery box increases and decreases periodically, which is beneficial to the complete discharge of the combustible gas inside the battery in the battery box and prevents the risk of re-ignition; finally, the deceleration mechanism can make the rotating disk rotate at a speed lower than the screw, so that the speed of the rotating disk will not be too high, and the frequency of the periodic overlap and intersect of the spray holes and the nozzles can be reduced, that is, the frequency of intermittent spraying is reduced to prevent the frequency from being too fast and causing the low pressure and high pressure in the battery box to be close, resulting in poor discharge effect of the combustible gas generated in the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a schematic diagram of the internal structure of an intermittent spraying liquid fire extinguishing device with a deceleration mechanism;

[0023] Figure 2 is a schematic diagram of the structure of the reduction mechanism in cooperation with the rotating disk and the front cover;

[0024] Figure 3 is a schematic diagram of the three-dimensional structure of the front cover and the fixed outer gear ring;

[0025] FIG4 is a schematic diagram of the three-dimensional structure of the front cover;

[0026] FIG5 is a schematic diagram of the planar structure of the rotating disk;

[0027] FIG6 is a schematic diagram of the planar structure of the piston and the inner wall of the housing. DETAILED DESCRIPTION

[0028] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0029] As shown in Figures 1 to 6, an intermittent spraying liquid fire extinguishing device with a deceleration mechanism includes a shell 1 and a gas-generating fire extinguishing agent 2 arranged in the shell 1. A front cover 3 is provided on the front side of the shell 1, and a nozzle 4 is opened on the surface of the front cover 3. The end face of the gas-generating fire extinguishing agent 2 is connected to one end of the starting component 5. A piston 7 is provided in the shell 1 and is slidably matched with the piston 7. The piston 7 is connected to the bottom of the front cover 3 through a screw 6.1 of a ball screw mechanism 6. The top of the screw 6.1 is fixedly connected to the center of a rotating disk 8 through a deceleration mechanism. Liquid fire extinguishing agent 12 is provided between the piston 7 and the front cover 3. A nozzle 9 is opened on the surface of the rotating disk 8. When the rotating disk 8 rotates, the nozzle 9 and the nozzle 4 periodically overlap and intersect.

[0030] Preferably, the ball screw mechanism 6 includes a nut 6.2 fixedly mounted inside the piston 7, and the spiral groove area where the nut 6.2 contacts the screw 6.1 is filled with balls. The ball screw mechanism 6 is a commonly used component in the field of mechanical engineering, and includes the nut 6.2, the screw 6.1, a ball return pipe, balls, a dust cover, a deflector, and other components. Since the balls roll along the spiral groove area formed by the screw and nut during operation, the movement resistance is extremely small. Therefore, when the piston 7 is compressed and moves upward, it drives the nut 6.2 upward, and the screw 6.1 rotates, thereby driving the rotating disk 8 to rotate.

[0031] Preferably, the gas-generating fire extinguishing agent 2 is a columnar structure formed by pressing aerosol generating agent powder, and the liquid fire extinguishing agent 12 is perfluorohexanone fire extinguishing agent. This pressed columnar aerosol generating agent burns more slowly than powdered aerosol generating agents, ensuring the continuous release of the fire extinguishing agent. The aerosol generating agent produces a large amount of gas when it burns, which drives the piston 7. The perfluorohexanone fire extinguishing agent used for the liquid fire extinguishing agent 12 has a boiling point of 49°C and easily vaporizes due to the high temperature when a fire occurs, thereby changing the air pressure in the release area.

[0032] The aerosol generator is a prior art, for example, the invention patent with Chinese patent publication number CN101745195B discloses an "aging-resistant aerosol generator and its preparation process", which discloses that the aerosol generator is composed of an oxidant, a reducing agent, and a binder, wherein the oxidant is potassium nitrate, the binder is phenolic resin, and the reducing agent is melamine, and the mass percentages thereof are: potassium nitrate 74% to 80%, phenolic resin 8% to 15%, and the balance is melamine.

[0033] Its preparation method is:

[0034] Step 1: dissolving phenolic resin in ethanol to prepare a phenolic resin solution with a mass percentage concentration of 40% to 55%;

[0035] Step 2: Grind the oxidizing agent and reducing agent to a fineness of 80-200 standard mesh, mix them according to the required proportion, and sieve them through 80-200 mesh three times to make them evenly mixed;

[0036] Step 3: Then add the phenolic resin solution to the mixed powder, stir for 10 minutes, and then use a 40-mesh screen to force granulate. Then dry the agent in an environment with a temperature of 40°C and a relative humidity of less than 20% until the volatile components are less than 1%;

[0037] Step 4: Press the dried medicine under a pressure of 10 MPa to form an aerosol generating agent column structure.

[0038] Preferably, the starting component 5 is an electric ignition head or a thermal wire structure. When the starting component 5 is an electric ignition head structure, it can be connected to a fire detection device, which is a temperature sensor and / or a smoke sensor. When a fire, overheating, or the like occurs, the fire detection device detects the high temperature environment generated in the battery compartment due to the fire and sends a signal to the microprocessor, which controls the starting component 5 to ignite the gas-generating fire extinguishing agent 2. When the starting component 5 is a thermal wire structure, the thermal wire structure can be directly ignited when a fire occurs, and then the thermal wire directly ignites the gas-generating fire extinguishing agent 2, without the need for additional fire detection devices and other external equipment, which is simpler and less costly.

[0039] Preferably, the outer edge of the front cover 3 is threadedly connected to the top of the housing 1, the bottom of the housing 1 is threadedly connected to the outer edge of the rear cover 10, and the bottom of the screw 6.1 is rotatably connected to the center of the rear cover 10 via a bearing. The gas-generating fire extinguishing agent 2 is located in the area where the rear cover 10 is located, and a silicone layer 11 is provided between the outer surface of the gas-generating fire extinguishing agent 2 and the inner surface of the rear cover 10. This threaded connection improves the convenience of installation of the entire fire extinguishing device and facilitates the production process. In addition, in the present invention, the bearing can effectively limit the screw 6.1, making its rotation process stable and reliable, while preventing the screw 6.1 from axial movement. The silicone layer 11 can effectively isolate the heat generated by the combustion of the gas-generating fire extinguishing agent 2, preventing the surface temperature of the rear cover 10 and the housing 1 from being too high.

[0040] Preferably, a guide rail 13 is vertically provided on the inner side of the housing 1, and a guide groove 14 is provided on the outer side of the piston 7, and the guide groove 14 slides with the guide rail 13. The sliding cooperation between the guide groove 14 and the guide rail 13 can ensure the stability of the movement of the piston 7 and prevent the piston 7 from rotating radially.

[0041] Preferably, the reduction mechanism includes a central gear 15 fixedly connected to the top of the screw 6.1, the central gear 15 is meshed with the inner sides of three planetary gears 16, the radius of the central gear 15 is smaller than the radius of the planetary gears 16, the outer sides of the planetary gears 16 are meshed with the inner sides of the fixed outer ring gear 17, the outer sides of the fixed outer ring gear 17 are fixed to the inner side of the front cover 3, the top center of the rotating disk 8 is rotationally connected to the front cover 3, and the top center of the planetary gears 16 is rotationally connected to the bottom of the rotating disk 8. After such design, when the screw 6.1 drives the central gear 15 to rotate, it drives the three planetary gears 16 to rotate. Since the outer side of the planetary gear 16 is meshed with the inner side of the fixed outer ring gear 17, the planetary gear 16 makes a circular motion around the central gear 15, thereby driving the rotating disk 8 to rotate. In the above process, since the radii of the central gear 15 and the planetary gears 16 are different (the radius of the central gear 15 is smaller than the radius of the planetary gears 16), a deceleration effect can be achieved. This is the principle of the planetary gear reduction mechanism. Ultimately, the rotating disk 8 can be rotated at a speed lower than that of the screw 6.1. In this way, the speed of the rotating disk 8 will not be too high, and the frequency of the periodic overlap and interlacing of the spray hole 9 and the nozzle 4 can be reduced, that is, the frequency of intermittent spraying is reduced to prevent the frequency from being too fast and resulting in poor pulse effect. In addition, too fast a frequency will make the low pressure and high pressure in the battery box close to each other, resulting in poor discharge effect of the combustible gas generated in the battery.

[0042] Preferably, the top center axis of the rotating disk 8 is rotationally connected to the front cover 3 through a bearing, and the top center of the planetary gear 16 is rotationally connected to the pin hole at the bottom of the rotating disk 8 through a pin shaft.

[0043] Preferably, the three planetary gears 13 are evenly distributed in a circular array with the central gear 12 as the center, and three spray holes 9 are opened on the surface of the rotating disk 8. The three spray holes 9 are also evenly distributed in a circular array with the central gear 12 as the center, and the three spray holes 9 and the three planetary gears 13 are staggered with each other.

[0044] Preferably, a diaphragm is also attached to the nozzle 4 on the surface of the front cover 3, which can prevent moisture in the outside air from entering through the nozzle 4 during storage and transportation, causing the fire extinguishing agent to absorb moisture. At the same time, it is easy to rupture when under pressure, so it does not affect the spraying process of the fire extinguishing device.

[0045] During the actual production of the fire extinguishing device, a certain gap can be reserved between the rotating disk 8 and the front cover 3. If the rotation of the rotating disk 8 is obstructed or the pressure in the shell 1 increases suddenly, if the spray hole 9 and the nozzle 4 are in an interlaced state at this time, the airflow there will directly pass through the gap and the nozzle 4 into the outside to release the pressure.

[0046] In order to ensure that the perfluorohexanone liquid fire extinguishing agent does not leak out of the gap in the contact area between the piston 7 and the screw 6.1 during the storage and transportation stage, a sealing ring can be added in the contact area between the lower end of the piston 7 and the screw 6.1 to effectively prevent the above-mentioned leakage.

[0047] In addition, the present invention also discloses a fire extinguishing method of the intermittent spraying liquid fire extinguishing device with a deceleration mechanism, which comprises the following steps:

[0048] S1: When a battery in the battery box experiences thermal runaway, the starting component 5 ignites the gas-generating fire extinguishing agent 2, and the gas-generating fire extinguishing agent 2 generates gas;

[0049] S2: The airflow pushes the piston 7 to move to the position of the front cover 3, and the ball screw mechanism 6 causes the screw 6.1 to rotate.

[0050] S3: When the screw 6.1 rotates, it is decelerated by the reduction mechanism, driving the rotating disk 8 to rotate at a speed lower than that of the screw 6.1, so that the spray holes 9 on the surface of the rotating disk 8 and the nozzles 4 on the surface of the front cover 3 periodically overlap and intersect;

[0051] S4: When the spray hole 9 and the nozzle 4 coincide with each other, the liquid fire extinguishing agent 12 is sprayed out from the nozzle 4, and is converted into gaseous state by the high temperature in the battery box to extinguish the fire in the battery box. When the spray hole 9 and the nozzle 4 are staggered, the shell 1 is sealed and a pressure-holding process is performed. Finally, the above process is repeated periodically to realize an intermittent spraying process, so that the pressure in the battery box increases and decreases periodically. In this step, when the fire extinguishing material is sprayed from the nozzle to extinguish the fire in the battery box, the gas inside the battery box increases, causing the pressure to increase. When the shell is sealed and a pressure-holding process is performed, the internal pressure of the battery box is released from the gap of the battery box itself, and the pressure decreases. Therefore, the pressure in the battery box increases and decreases periodically.

[0052] S5: When the pressure inside the battery compartment increases, the flammable gas diluted with the fire extinguishing agent is forced out through the gaps in the battery compartment. When the pressure inside the battery compartment decreases, the flammable gas inside the battery escapes and enters the battery compartment, repeating the above process. Through this reciprocating cycle of low and high pressure, the flammable gas generated in the battery can be diluted with the fire extinguishing agent and continuously discharged from the battery compartment, completing the entire fire extinguishing process and effectively preventing the risk of re-ignition.

[0053] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The embodiments and features in the embodiments of this application may be arbitrarily combined with each other unless they conflict. The scope of protection of the present invention shall be the technical solutions described in the claims, including equivalent alternatives to the technical features of the technical solutions described in the claims. Equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. An intermittent spraying liquid fire extinguishing device with a deceleration mechanism, comprising a housing (1) and a gas-generating fire extinguishing agent (2) arranged in the housing (1), a front cover (3) being arranged on the front side of the housing (1), a nozzle (4) being arranged on the surface of the front cover (3), an end face of the gas-generating fire extinguishing agent (2) being connected to one end of a starting component (5), characterized in that: A piston (7) is provided in the housing (1) and is slidably matched therewith. The piston (7) is connected to the bottom of the front cover (3) through a screw rod (6.1) of a ball screw mechanism (6). The top of the screw rod (6.1) is fixedly connected to the center of a rotating disk (8) through a speed reduction mechanism. A liquid fire extinguishing agent (12) is provided between the piston (7) and the front cover (3). A spray hole (9) is provided on the surface of the rotating disk (8). When the rotating disk (8) rotates, the spray hole (9) and the nozzle (4) periodically overlap and intersect.

2. The intermittent spraying liquid fire extinguishing device with a deceleration mechanism according to claim 1 is characterized in that: The ball screw mechanism (6) comprises a nut (6.2) fixedly arranged inside the piston (7), and a spiral groove area where the nut (6.2) contacts the screw rod (6.1) is filled with balls.

3. The intermittent spraying liquid fire extinguishing device with a deceleration mechanism according to claim 1 is characterized in that: The gas-generating fire extinguishing agent (2) is a columnar structure formed by pressing aerosol generating agent powder, and the liquid fire extinguishing agent (12) is a perfluorohexanone fire extinguishing agent.

4. The intermittent spraying liquid fire extinguishing device with a deceleration mechanism according to claim 1 is characterized in that: The starting component (5) is an electric ignition head or a thermal wire structure.

5. The intermittent spraying liquid fire extinguishing device with a deceleration mechanism according to claim 1 is characterized in that: The outer edge of the front cover (3) is threadedly connected to the top of the shell (1), the bottom of the shell (1) is threadedly connected to the outer edge of the rear cover (10), and the bottom of the screw (6.1) is rotatably connected to the center of the rear cover (10) via a bearing; the gas-generating fire extinguishing agent (2) is located in the area where the rear cover (10) is located, and a silica gel layer (11) is provided between the outer surface of the gas-generating fire extinguishing agent (2) and the inner surface of the rear cover (10).

6. The intermittent spraying liquid fire extinguishing device with a deceleration mechanism according to claim 1, characterized in that: A guide rail (13) is also vertically arranged on the inner side of the housing (1), and a guide groove (14) is provided on the outer side of the piston (7), wherein the guide groove (14) is slidably matched with the guide rail (13).

7. The intermittent spraying liquid fire extinguishing device with a deceleration mechanism according to claim 1 is characterized in that: The speed reduction mechanism comprises a central gear (15) fixedly connected to the top of the screw rod (6.1); the central gear (15) meshes with the inner sides of three planetary gears (16); the radius of the central gear (15) is smaller than the radius of the planetary gears (16); the outer sides of the planetary gears (16) mesh with the inner sides of a fixed outer gear ring (17); the outer sides of the fixed outer gear ring (17) are fixed to the inner side of the front cover (3); the top center of the rotating disk (8) is rotationally connected to the front cover (3); and the top center of the planetary gears (16) is rotationally connected to the bottom of the rotating disk (8).

8. The intermittent spraying liquid fire extinguishing device with a deceleration mechanism according to claim 7 is characterized in that: The top center axis of the rotating disk (8) is rotationally connected to the front cover (3) via a bearing, and the top center of the planetary gear (16) is rotationally connected to the bottom pin hole of the rotating disk (8) via a pin shaft.

9. The intermittent spraying liquid fire extinguishing device with a deceleration mechanism according to claim 7, characterized in that: The three planetary gears (13) are evenly distributed in a circular array with the central gear (12) as the center. The surface of the rotating disk (8) is provided with three spray holes (9). The three spray holes (9) are also evenly distributed in a circular array with the central gear (12) as the center. The three spray holes (9) and the three planetary gears (13) are staggered with each other.

10. An intermittent spraying liquid fire extinguishing device with a deceleration mechanism according to any one of claims 1 to 9, characterized in that: It includes the following steps: S1: When a battery in the battery box experiences thermal runaway, the starting component (5) ignites the gas-generating fire extinguishing agent (2), and the gas-generating fire extinguishing agent (2) generates gas; S2: The airflow pushes the piston (7) to move toward the position of the front cover (3), and the ball screw mechanism (6) causes the screw (6.1) to rotate. S3: When the screw (6.1) rotates, it is decelerated by the speed reducing mechanism, and drives the rotating disk (8) to rotate at a speed lower than that of the screw (6.1), so that the spray holes (9) on the surface of the rotating disk (8) and the spray ports (4) on the surface of the front cover (3) are periodically overlapped and staggered; S4: When the spray hole (9) and the nozzle (4) overlap, the liquid fire extinguishing agent (12) is sprayed out from the nozzle (4) and, under the action of the high temperature in the battery box, is converted into a gaseous state to extinguish the fire in the battery box. When the spray hole (9) and the nozzle (4) intersect, the housing (1) is sealed and a pressure holding process is performed. Finally, the above process is repeated periodically to realize an intermittent spraying process, so that the pressure in the battery box increases and decreases periodically. S5: When the pressure in the battery box increases, the combustible gas diluted by the fire extinguishing material is pressed out from the gaps in the battery box. When the pressure in the battery box decreases, the combustible gas inside the battery escapes and enters the battery box, and the above process is repeated in a cycle.

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