Fire extinguishing protection device for oil-immersed transformer
By using oil discharge and nitrogen fire extinguishing methods in oil-immersed transformers, the difficulty of using water spray systems to extinguish fires in remote, water-deficient or low-temperature areas is solved, and efficient cooling and fire protection of transformer oil is achieved, ensuring equipment security and reliability.
Patent Information
- Application Number
- CN202420340746.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-23
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-02-23
AI Technical Summary
In some remote, relatively water-deficient and low temperature areas, it is very difficult to use water spray systems to extinguish fire to protect transformer equipment.
Provide a fire extinguishing protection device for oil-immersed transformers, including the transformer body, fire control cabinet, fire detector, oil replenishment pipe, oil drain pipe, air intake pipe, fire extinguishing protection components, etc., the oil in the transformer is discharged through the oil drain pipe, and the fire extinguishing protection is used to discharge the oil in the transformer through the oil drain pipe, and the fire extinguishing protection is used. The nitrogen pass-through pipe in the component inputs nitrogen into the oil tank in the transformer, stirs the transformer oil, and forcefully cools and forms a nitrogen protective layer to isolate the air inlet and prevents oil from burning.
It effectively solves the difficulty of extinguishing fire to protect the transformer in water-deficient or low-temperature environments. Through nitrogen fire extinguishing technology, efficient cooling and fire protection of transformer oil is achieved, ensuring the safety and reliability of the transformer.
Smart Images
Figure CN222483086U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of oil-immersed transformers, in particular to a fire extinguishing protection device for oil-immersed transformers. Background Art
[0002] Oil-immersed power transformers are one of the most important equipment in power stations and substations. The transformer body contains a large amount of flammable substances. Transformer combustion is generally caused by internal insulation damage, mainly due to overload, operating overvoltage and lightning overvoltage, gradual insulation degradation, etc. The arc caused by electrical faults generates energy that causes temperature and pressure to accumulate in the transformer body, forcing the transformer top cover to fly off or causing the body to be damaged, and a large amount of fuel oil gushes out over a large area, causing the fire to spread.
[0003] Traditional transformer fire extinguishing mainly uses water sprinkler system, but the use of water sprinkler system must have a complete system including water pool and water pump, and the operating temperature is also limited. Therefore, when used in some remote, relatively water-scarce and low-temperature areas, it is very difficult to use water sprinkler system to extinguish fire and protect transformer equipment. Utility Model Content
[0004] The embodiment of the present application provides a fire extinguishing protection device for an oil-immersed transformer, thereby solving the problem in the prior art that it is very difficult to use a water sprinkler system to extinguish fire and protect transformer equipment when used in some remote, relatively water-scarce, and low-temperature areas.
[0005] The embodiment of the present application provides a fire extinguishing protection device for an oil-immersed transformer, comprising a transformer body and a fire control cabinet, wherein a fire detector is fixed on the transformer body, an oil supply pipe is fixed on the transformer body, and a stop valve is fixed on the oil supply pipe;
[0006] An oil drain pipe is fixed on the top of the transformer body, the oil inlet end of the oil drain pipe extends into the transformer body, and an air inlet pipe is fixed on the bottom of the transformer body;
[0007] A plurality of branch pipes are fixed on the outlet end of the air inlet pipe, the outlet end of each branch pipe extends into the transformer body, and a safety valve is fixed on each branch pipe;
[0008] It also includes a fire extinguishing protection component, which extinguishes the fire of the transformer body by draining oil and injecting nitrogen.
[0009] Furthermore, the fire detector is a glass ball type fire detector, the number of the fire detectors is more than 6, and they are cross-arranged on the transformer body to form two independent loops.
[0010] Furthermore, the fire extinguishing protection assembly includes a box, a nitrogen bottle, an oil guide pipe and a nitrogen passage pipe;
[0011] The box is parallel to the transformer body, the oil guide pipe is fixed in the box, and the nitrogen gas pipe is fixed on the top of the box;
[0012] The oil outlet end of the oil discharge pipe is sealed and fixed to the oil inlet end of the oil guide pipe, and the air inlet end of the air inlet pipe is sealed and fixed to the air outlet end of the nitrogen passage pipe.
[0013] Furthermore, the nitrogen cylinder and the nitrogen passage are sealed and connected via a nitrogen release pipe, and a nitrogen release valve is fixed on the nitrogen release pipe;
[0014] An oil drain valve is fixed on the oil guide pipe, and the oil drain valve and the nitrogen gas passage pipe are connected via a mechanical interlocking mechanism;
[0015] An oil and gas isolation valve is fixed on the nitrogen passage pipe, and the oil and gas isolation valve is located above the nitrogen release valve.
[0016] Furthermore, an oil drain pipe observation window is fixed on the oil guide pipe near the oil drain valve, and an oil leakage alarm device is fixed in the oil drain pipe observation window;
[0017] A service valve is fixed on the oil guide pipe at a position far away from the oil drain valve.
[0018] Furthermore, an anti-error electromagnet is fixed to the oil drain valve.
[0019] Furthermore, it also includes a cooling component;
[0020] The cooling component includes a coolant tank, a water pipe and a cold water pipe;
[0021] The coolant tank is fixed on the box body;
[0022] A heat dissipation fin is fixed at the bottom of the coolant tank, and one end of the heat dissipation fin extends out of the coolant tank;
[0023] The water inlet end of the water guide pipe extends into the coolant tank, and the water outlet end of the water guide pipe is connected to the water inlet end of the cold water pipe;
[0024] The cold water pipe is a disc-shaped pipe, and is fixed on the oil guide pipe. The cold water pipe is in contact with the surface of the oil guide pipe, and the water outlet end of the cold water pipe extends into the coolant tank.
[0025] Furthermore, the cooling component further comprises a cooling fan, a ventilation net and a through slot, wherein the through slot is opened on the box body, the cooling fan is fixed in the through slot, and the cooling fan is parallel to the cold water pipe;
[0026] The ventilation net is fixed on the box body, the ventilation net is parallel to the heat dissipation fan, a turntable is rotatably connected on the outer peripheral edge of the ventilation net, and a plurality of brush heads are evenly fixed on one end of the turntable close to the ventilation net.
[0027] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:
[0028] The oil in the transformer body is discharged through the oil drain pipe, and nitrogen is input into the oil tank in the transformer body through the air inlet pipe through the set fire extinguishing protection component, which can stir the transformer oil, forcefully cool the fault point and the oil temperature, and form a nitrogen protective layer to isolate the entry of air, so that the transformer oil cannot burn, thereby achieving the purpose of fire prevention and fire extinguishing. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 It is a three-dimensional structural schematic diagram of the fire extinguishing protection device for oil-immersed transformers of the utility model;
[0030] Figure 2 It is a front view structural diagram of the fire extinguishing protection device for oil-immersed transformer of the utility model;
[0031] Figure 3 It is a schematic diagram of the front cross-sectional structure of the box of the fire extinguishing protection device for oil-immersed transformer of the utility model;
[0032] Figure 4 It is a schematic diagram of the motion state structure of the mechanical interlocking mechanism of the utility model when the oil drain valve of the fire extinguishing protection device for oil-immersed transformer is opened;
[0033] Figure 5 It is a schematic diagram of the front cross-sectional structure of the coolant tank of the fire extinguishing protection device for oil-immersed transformers of the utility model;
[0034] Figure 6 It is a rear view structural diagram of the ventilation network of the fire extinguishing protection device for oil-immersed transformer of the utility model;
[0035] Figure 7 The utility model is a schematic diagram of the three-dimensional structure of a turntable of a fire extinguishing protection device for an oil-immersed transformer.
[0036] In the figure: 100, transformer body; 110, fire detector; 120, oil supply pipe; 121, cut-off valve; 130, oil drain pipe; 140, air inlet pipe; 141, branch pipe; 142, safety valve;
[0037] 200, fire protection assembly; 210, box; 220, nitrogen bottle; 230, oil guide pipe; 231, oil drain pipe observation window; 232, oil drain valve; 233, inspection valve; 240, nitrogen vent pipe; 241, nitrogen release pipe; 242, mechanical interlocking mechanism; 243, oil and gas isolation valve; 244, anti-error electromagnet; 250, cooling assembly; 251, coolant tank; 252, cooling fins; 253, water guide pipe; 254, cooling fan; 255, cold water pipe; 256, ventilation net; 257, turntable; 2571, brush head; 300, fire control cabinet. DETAILED DESCRIPTION
[0038] To facilitate the understanding of the present invention, the present application will be described more comprehensively below with reference to the relevant drawings; the drawings show preferred embodiments of the present invention, but the present invention can be implemented in many different forms and is not limited to the embodiments described herein; on the contrary, the purpose of providing these embodiments is to enable a more thorough and comprehensive understanding of the disclosed content of the present invention.
[0039] It should be noted that the terms “vertical”, “horizontal”, “up”, “down”, “left”, “right” and similar expressions used in this document are only for illustrative purposes and do not represent the only implementation method.
[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field of the present invention; the terms used in the specification of the present invention are only for the purpose of describing specific implementation methods and are not intended to limit the present invention; the term "and / or" used herein includes any and all combinations of one or more related listed items.
[0041] like Figures 1 to 7As shown, the present application provides a fire extinguishing protection device for an oil-immersed transformer, including a transformer body 100 and a fire control cabinet 300. The fire control cabinet 300 is used for signal reception, execution relays, working state selection knobs, signal indicator lights and other components, providing working state signal indication, alarm signal output and start control. A fire detector 110 is fixed on the transformer body 100. The fire detector 110 is used to detect the temperature inside the transformer body 100. An oil replenishing pipe 120 is fixed on the transformer body 100. The oil replenishing pipe 120 is connected to the oil storage cabinet through a pipeline. The oil replenishing pipe 120 It is used to replenish oil in the transformer main body 100. A stop valve 121 is fixed on the oil replenishment pipe 120. When the oil is discharged and the pressure is released, the stop valve 121 reaches the set flow rate and automatically cuts off the oil replenishment oil path from the oil conservator to the transformer main body 100, so as to prevent the high-position oil conservator from "adding fuel to the fire". An oil drain pipe 130 is fixed on the top of the transformer main body 100. The oil inlet end of the oil drain pipe 130 extends into the transformer main body 100. The oil drain pipe 130 is used to discharge the oil in the transformer main body 100. An air intake pipe 140 is fixed on the bottom of the transformer main body 100. The air intake pipe 140 is used to inject nitrogen into the transformer main body 100 to extinguish the fire;
[0042] A plurality of branch pipes 141 are fixed to the outlet end of the air inlet pipe 140, and the outlet end of each branch pipe 141 extends into the transformer body 100, and a safety valve 142 is fixed to each branch pipe 141. The safety valve 142 is used to prevent chronic leakage gas from accumulating in the air inlet pipe 140 and entering the transformer body 100, thereby avoiding accidents.
[0043] It also includes a fire extinguishing protection component 200, which performs fire extinguishing treatment on the transformer body 100 by draining oil and injecting nitrogen.
[0044] Specifically, if Figure 1 and Figure 2 As shown, the fire detector 110 is a glass ball type fire detector, the number of the fire detectors 110 is more than 6, and they are cross-arranged on the transformer body 100 to form two independent loops.
[0045] It is worth noting that when the oil inside the transformer body 100 burns, it reaches the set temperature of the fire detector 110 on the transformer body 100, so that the two independent fire detectors 110 are activated at the same time, and the fire extinguishing protection is started. The oil in the transformer body 100 is discharged through the oil drain pipe 130. After the oil discharge time is adjustable from 3S2S to 20S, nitrogen is sent into the air inlet pipe 140 through the set fire extinguishing protection component 200, and the nitrogen is input into the oil tank in the transformer body 100 through the air inlet pipe 140, which can stir the transformer oil and force cooling of the fault point and the oil temperature.
[0046] Specifically, if Figures 1 to 4As shown, the fire extinguishing protection assembly 200 includes a box 210, a nitrogen bottle 220, an oil guide pipe 230 and a nitrogen gas pipe 240;
[0047] The box body 210 is parallel to the transformer body 100, the oil guide pipe 230 is fixed in the box body 210, and the nitrogen gas pipe 240 is fixed at the top of the box body 210;
[0048] The oil outlet end of the oil discharge pipe 130 is sealed and fixed to the oil inlet end of the oil guide pipe 230 , and the air inlet end of the air inlet pipe 140 is sealed and fixed to the air outlet end of the nitrogen gas passage 240 .
[0049] It is worth noting that the transformer oil in the transformer body 100 is input into the oil guide pipe 230 through the oil drain pipe 130 , and the nitrogen is input into the air inlet pipe 140 through the nitrogen gas passage 240 .
[0050] Specifically, if Figure 3 and Figure 4 As shown, a nitrogen cylinder head valve is fixed on the nitrogen cylinder 220, and the nitrogen cylinder 220 and the nitrogen passage 240 are sealed and connected via a nitrogen release pipe 241. A nitrogen release valve is fixed on the nitrogen release pipe 241. The nitrogen release valve is a valve that can release nitrogen after receiving a start signal from the fire control cabinet 300. When the oil drain valve 232 is opened to discharge the oil at the top of the transformer body 100, the nitrogen release valve is opened at the same time;
[0051] The oil drain valve 232 is fixed on the oil guide pipe 230. The oil drain valve 232 is a quick-opening valve for draining oil and relieving pressure. The oil drain valve 232 and the nitrogen gas passage 240 are connected via a mechanical interlocking mechanism 242.
[0052] An oil and gas isolation valve 243 is fixed on the nitrogen passage pipe 240 , and the oil and gas isolation valve 243 is located above the nitrogen release valve.
[0053] It is worth noting that by installing a mechanical interlocking mechanism 242 between the oil drain valve 232 and the nitrogen vent pipe 240, that is, the oil drain valve 232 is not actuated, the mechanical interlocking valve before the oil and gas isolation valve 243 will not open even if the nitrogen release valve and the nitrogen bottle head valve are opened, thereby preventing nitrogen from being injected without draining the oil, which would cause damage to the shell of the transformer body 100.
[0054] Specifically, if Figure 3 and Figure 4 As shown, an oil drain pipe observation window 231 is fixed on the oil guide pipe 230 near the oil drain valve 232, and an oil leakage alarm device is fixed in the oil drain pipe observation window 231. The oil leakage alarm device is used to prevent the oil leakage of the oil drain pipe from causing the gas relay to operate. The oil leakage alarm device is located in the oil drain pipe observation window 231 for easy maintenance;
[0055] A check valve 233 is fixed on the oil guide pipe 230 away from the oil drain valve 232 , and the check valve 233 can provide a check status signal to the fire control cabinet 300 .
[0056] Specifically, if Figure 3 and Figure 4 As shown, an anti-error electromagnet 244 is fixed to the oil drain valve 232;
[0057] It is worth mentioning that when the oil is drained and the pressure is released, the anti-error electromagnet 244 is actuated, and the oil drain valve 232 is first unlocked by the mechanical interlocking mechanism 242. After the anti-error electromagnet 244 is actuated, the electrical interlock is released, and the oil drain valve 232 can be started. The oil drain valve 232 can only be started when both are actuated at the same time.
[0058] In the above embodiment, when a fault occurs inside the transformer, a large amount of flammable gas is generated inside the oil tank, causing the gas relay to actuate and close the contacts, causing the circuit breaker to trip. At this time, if the pressure of the transformer oil tank continues to increase and exceeds the set value of the oil tank overpressure switch, the explosion-proof and fire-proof program is activated; at this time, if the oil inside the transformer burns and reaches the set temperature of the fire detector on the transformer, the two independent detectors are actuated at the same time, and the fire extinguishing protection is activated;
[0059] The oil drain valve 232 is opened to drain the oil in the transformer body 100 through the oil drain pipe 130. At the same time, the cut-off valve 121 under the transformer oil conservator reaches the set flow rate and automatically cuts off the oil supply path from the oil conservator to the transformer body. After the oil drain time is adjustable from 3S2S to 20S, the oil drain valve 232 is opened to discharge the oil at the top of the transformer body 100. At the same time, the nitrogen release valve is opened to send nitrogen into the air inlet pipe 140. The nitrogen is input into the oil tank in the transformer body 100 through the air inlet pipe 140 to stir the transformer oil, forcefully cool the fault point and the oil temperature, and form a nitrogen protective layer to isolate the air from entering, so that the transformer oil cannot burn, thereby achieving the purpose of fire prevention, explosion prevention and fire extinguishing. Subsequently, nitrogen is continuously injected for more than 30 minutes, and a large amount of reduced pressure cooling nitrogen fully stirs the transformer oil in the transformer body 100 to cool the fault point temperature. When the oil temperature drops below the ignition point and flash point, the fire is completely extinguished to prevent re-ignition.
[0060] In some embodiments of the present application, Figures 3 to 5 As shown, it also includes a cooling component 250, which is used to cool the transformer oil and reduce damage to the oil guide pipe 230;
[0061] The cooling assembly 250 includes a cooling liquid tank 251, a water pipe 253 and a cold water pipe 255;
[0062] The coolant tank 251 is fixed on the box body 210, and the coolant tank 251 stores coolant for cooling the surface of the oil guide pipe 230;
[0063] A heat dissipation fin 252 is fixed at the bottom of the coolant tank 251, one end of the heat dissipation fin 252 extends out of the coolant tank 251, and the connection between the heat dissipation fin 252 and the coolant tank 251 is sealed and fixed, so that no leakage occurs;
[0064] The water inlet end of the water pipe 253 extends into the coolant tank 251, the water outlet end of the water pipe 253 is connected to the water inlet end of the cold water pipe 255, and the water pipe 253 is connected to the water pump;
[0065] The cold water pipe 255 is a disc-shaped pipe, and is fixed on the oil guide pipe 230 . The cold water pipe 255 is in contact with the surface of the oil guide pipe 230 , and the water outlet end of the cold water pipe 255 extends into the coolant tank 251 .
[0066] It is worth noting that the flow speed of the coolant slows down when passing through the disc-shaped cold water pipe 255, which can take away the heat at the oil guide pipe 230 and cool the oil guide pipe 230 when the oil guide pipe 230 transports the transformer oil.
[0067] Specifically, if Figures 3 to 7 As shown, the cooling assembly 250 further includes a cooling fan 254, a ventilation net 256 and a through slot, the through slot is opened on the box body 210, the cooling fan 254 is fixed in the through slot, and the cooling fan 254 is parallel to the cold water pipe 255;
[0068] The ventilation net 256 is fixed on the box body 210 , and the ventilation net 256 is parallel to the cooling fan 254 . A turntable 257 is rotatably connected to the outer periphery of the ventilation net 256 , and a plurality of brush heads 2571 are evenly fixed on one end of the turntable 257 close to the ventilation net 256 .
[0069] It is worth noting that the cooling fan 254 can drive the air flow near the cold water pipe 255, and at the same time can dissipate the heat in the box 210, and accelerate the cooling of the oil guide pipe 230. The ventilation net 256 can not only maintain air circulation, but also play a role in dust prevention. When the mesh of the ventilation net 256 is blocked, the turntable 257 can be rotated to make the brush head 2571 sweep through the ventilation net 256 to sweep away the dust at the mesh of the ventilation net 256.
[0070] In the above embodiment, when the transformer oil passes through the oil guide pipe 230, the temperature of the surface of the oil guide pipe 230 will increase, and metal fatigue is likely to occur over a long period of time. The coolant in the coolant tank 251 is pumped into the water guide pipe 253 by a water pump, and the coolant is sent to the cold water pipe 255 through the water guide pipe 253. The flow speed of the coolant slows down when passing through the disc-shaped cold water pipe 255, and the heat at the oil guide pipe 230 can be taken away. When the oil guide pipe 230 transports the transformer oil, the oil guide pipe 230 is cooled. After flowing through the cold water pipe 255, the coolant returns to the coolant tank 251 for recycling. At the same time, the cooling fan 254 is used to accelerate the flow of high-temperature gas near the oil guide pipe 230, which is convenient for cooling the oil guide pipe 230, improving the heat dissipation effect of the oil guide pipe 230, and increasing the service life of the oil guide pipe 230.
[0071] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. For those skilled in the art, the utility model may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.
Claims
1. A fire extinguishing protection device for an oil-immersed transformer, comprising a transformer body (100) and a fire control cabinet (300), characterized in that: A fire detector (110) is fixed on the transformer body (100), an oil supply pipe (120) is fixed on the transformer body (100), and a stop valve (121) is fixed on the oil supply pipe (120); An oil drain pipe (130) is fixed on the top of the transformer body (100), an oil inlet end of the oil drain pipe (130) extends into the transformer body (100), and an air inlet pipe (140) is fixed on the bottom of the transformer body (100); A plurality of branch pipes (141) are fixed on the outlet end of the air inlet pipe (140), the outlet end of each branch pipe (141) extends into the transformer body (100), and a safety valve (142) is fixed on each branch pipe (141); It also includes a fire extinguishing protection component (200), which performs fire extinguishing treatment on the transformer body (100) by draining oil and injecting nitrogen.
2. The fire extinguishing protection device for oil-immersed transformer according to claim 1, characterized in that: The fire detector (110) is a glass ball type fire detector, the number of the fire detectors (110) is more than 6, and the fire detectors (110) are cross-arranged on the transformer body (100) to form two independent loops.
3. The fire extinguishing protection device for oil-immersed transformer according to claim 1, characterized in that: The fire extinguishing protection assembly (200) comprises a box (210), a nitrogen bottle (220), an oil guide pipe (230) and a nitrogen passage pipe (240); The box (210) is parallel to the transformer body (100), the oil guide pipe (230) is fixed in the box (210), and the nitrogen gas pipe (240) is fixed on the top of the box (210); The oil outlet end of the oil discharge pipe (130) is sealed and fixed to the oil inlet end of the oil guide pipe (230), and the air inlet end of the air inlet pipe (140) is sealed and fixed to the air outlet end of the nitrogen gas passage pipe (240).
4. The fire extinguishing protection device for oil-immersed transformer according to claim 3, characterized in that: The nitrogen bottle (220) and the nitrogen passage pipe (240) are sealedly connected via a nitrogen release pipe (241), and a nitrogen release valve is fixed on the nitrogen release pipe (241); An oil drain valve (232) is fixed on the oil guide pipe (230), and the oil drain valve (232) and the nitrogen gas passage pipe (240) are connected via a mechanical interlocking mechanism (242); An oil and gas isolation valve (243) is fixed on the nitrogen passage pipe (240), and the oil and gas isolation valve (243) is located above the nitrogen release valve.
5. The fire extinguishing protection device for oil-immersed transformer according to claim 3, characterized in that: An oil drain pipe observation window (231) is fixed on the oil guide pipe (230) near the oil drain valve (232), and an oil leakage alarm device is fixed in the oil drain pipe observation window (231); A service valve (233) is fixed on the oil guide pipe (230) at a position away from the oil discharge valve (232).
6. The fire extinguishing protection device for oil-immersed transformer according to claim 4, characterized in that: An anti-error electromagnet (244) is fixed to the oil drain valve (232).
7. The fire extinguishing protection device for oil-immersed transformer according to claim 1, characterized in that: Also included is a cooling component (250); The cooling component (250) comprises a cooling liquid tank (251), a water pipe (253) and a cold water pipe (255); The cooling liquid tank (251) is fixed on the tank body (210); A heat dissipation fin (252) is fixed at the bottom of the coolant tank (251), and one end of the heat dissipation fin (252) extends out of the coolant tank (251); The water inlet end of the water guide pipe (253) extends into the coolant tank (251), and the water outlet end of the water guide pipe (253) is connected to the water inlet end of the cold water pipe (255); The cold water pipe (255) is a disc-shaped pipe and is fixed on the oil guide pipe (230). The cold water pipe (255) is in contact with the surface of the oil guide pipe (230), and the water outlet end of the cold water pipe (255) extends into the coolant tank (251).
8. The fire extinguishing protection device for oil-immersed transformer according to claim 7, characterized in that: The cooling component (250) further comprises a cooling fan (254), a ventilation net (256) and a through slot, wherein the through slot is opened on the box body (210), the cooling fan (254) is fixed in the through slot, and the cooling fan (254) is parallel to the cold water pipe (255); The ventilation net (256) is fixed on the box body (210), the ventilation net (256) is parallel to the cooling fan (254), the outer periphery of the ventilation net (256) is rotatably connected to a turntable (257), and a plurality of brush heads (2571) are evenly fixed on one end of the turntable (257) close to the ventilation net (256).