Enclosed transformer substation based on fire-fighting large-scale power grid safety guarantee

Abstract

The invention discloses a closed transformer substation based on fire-fighting large-scale power grid safety guarantee, and relates to the technical field of closed transformer substations, the closed transformer substation comprises a power transformation room, power transformation boxes and a cold water tower, the front and rear sides of the power transformation boxes are provided with heat dissipation mechanisms, the side end faces of the power transformation boxes are provided with fire-fighting mechanisms, and the power transformation boxes are uniformly installed in the power transformation room. A cold water flow channel is formed between the power transformation box and the power transformation room, the cold water tower comprises a tower body, a water outlet pipe, a return pipe and a refrigerator, the tower body is in through connection with the cold water flow channel through the water outlet pipe and the return pipe, and a circulating pump is arranged on the water outlet pipe; the movable radiator is in sliding connection with the fixed radiator through the temperature sensing telescopic rod. The system has the advantages of good heat dissipation effect and intelligent fire fighting, and solves the problems of low heat dissipation efficiency and slow fire fighting response speed of a closed power transformation box in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of closed substations, in particular to a closed substation based on fire protection large-scale power grid safety assurance. Background Art

[0002] With the acceleration of urbanization and the development of social economy, the demand for power systems is growing. As a key component of the power system, the stability and safety of substations directly affect the quality of power supply. Traditional substations usually adopt an open structure design. Although it meets the needs of early power systems to a certain extent, with the continuous increase of power load and technological advancement, open substations have gradually revealed many shortcomings.

[0003] Due to the limited space, heat dissipation has become an important issue for closed substations. Especially under high-load operating conditions, the temperature inside the substation is prone to rise, resulting in equipment performance degradation or even failure. The traditional air cooling method has low heat dissipation efficiency and cannot meet the heat dissipation requirements of modern power systems for high-density, high-power equipment. During operation, the substation may cause a fire due to electrical failures and other reasons. Once a fire occurs, if it cannot be extinguished in a timely and effective manner, the fire will spread rapidly, causing serious economic losses and even casualties. Traditional firefighting measures often rely on external firefighting facilities, and there are problems such as slow response speed and difficulty in quickly controlling the source of fire. Therefore, a closed substation based on fire-fighting large-scale power grid security is needed to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a closed substation based on fire protection large-scale power grid safety protection, which has the advantages of good heat dissipation effect and intelligent fire protection, and solves the problems of low heat dissipation efficiency and slow fire response speed of closed substation boxes in the prior art.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: A closed substation based on fire protection large-scale power grid safety protection, comprising a substation room and a substation box, and also comprising a cooling tower, the front and rear sides of the substation box are provided with a heat dissipation mechanism, and the side end surface of the substation box is provided with a fire protection mechanism; The transformer boxes are evenly installed in the transformer room, a cold water flow channel is formed between the transformer boxes and the transformer room, the cold water tower comprises a tower body, a water outlet pipe, a return pipe and a refrigerator, the tower body is connected to the cold water flow channel through the water outlet pipe and the return pipe, and a circulating pump is arranged on the water outlet pipe; The heat dissipation mechanism comprises a fixed heat sink, a movable heat sink and a temperature-sensitive telescopic rod, wherein the movable heat sink is slidably connected to the fixed heat sink via the temperature-sensitive telescopic rod; The fire fighting mechanism comprises a siphon, a stop valve, a limit plate and a rotating nozzle. The stop valve and the rotating nozzle are installed on the siphon, and the limit plate is movably installed on the transformer box to limit the opening of the stop valve.

[0006] As a preferred closed substation based on fire-fighting large-scale power grid safety protection of the present invention, the transformer boxes are installed alternately on the left and right sides in the transformer room, and the cold water flow channel contacts the front end face, left end face and rear end face of the transformer box. The fixed radiator is fixedly installed on the transformer box, and the upper end face of the fixed radiator is provided with a first heat dissipation tooth plate, and the front end face and the rear end face of the transformer box are provided with slide rails, and the back side of the movable radiator is provided with a slider cooperating with the slide rail, and the lower end face of the movable radiator is provided with a second heat dissipation tooth plate staggered with the first heat dissipation tooth plate.

[0007] As a preferred closed substation based on fire-fighting large-scale power grid safety protection of the present invention, the temperature-sensitive telescopic rod includes a temperature-sensitive tube and a piston rod, the temperature-sensitive tube includes a sleeve, a connecting pipe and a liquid storage tube, the liquid storage tube is installed on the inner end surface of the transformer box, the sleeve is installed on the outer end surface of the transformer box, the sleeve and the bottom of the transformer box are connected through a connecting pipe, the piston rod is inserted into the sleeve and slidably connected thereto, kerosene is arranged in the temperature-sensitive tube, and the top of the piston rod is fixedly connected to the top lower end surface of the movable radiator.

[0008] As a preferred closed substation based on fire protection large-scale power grid safety assurance of the present invention, the inner diameter of the sleeve is one fifth of the inner diameter of the temperature sensing tube, and the temperature sensing telescopic rod is made of stainless steel.

[0009] As a preferred closed substation based on fire protection large-scale power grid safety protection of the present invention, a reflective cover is provided on the side of the temperature sensing tube close to the substation, and fixing rings fixed to the temperature sensing tube are provided on the top and bottom of the reflective cover. The reflective cover is made of a mirror metal plate and has an arc-shaped structure.

[0010] As a preferred closed substation based on fire protection large-scale power grid safety protection of the present invention, the stop valve includes a valve housing, a valve stem and a spring, a sealing seat is arranged in the valve housing, the spring is sleeved on the valve stem, the valve stem is elastically slidably connected to the valve housing through the spring, and a limiting flange for limiting the spring is arranged on the valve stem.

[0011] As a preferred closed substation based on fire protection large-scale power grid safety protection of the present invention, the siphon is an "n" type pipe, the height of the coolant overflows the siphon, the stop valve is installed on the outside, the rotating nozzle is installed at the end of the siphon and is rotatably connected with it, the side of the rotating nozzle is provided with a spiral spray hole, the upper end face of the rotating nozzle is provided with an upper spray hole, the side end face of the transformer box is provided with a support frame, the support frame is provided with a slot, the limit plate is inserted into the slot and is slidably connected to the support frame, the limit plate includes a pressure plate, a sensing arm and a hanging arm, the spacing between the pressure plate and the sealing seat is equal to the length of the valve stem, and the pressure plate squeezes the valve stem so that it maintains close contact with the sealing seat.

[0012] As a preferred closed substation based on fire protection large-scale power grid safety assurance of the present invention, the induction arm is located at the upper end of the movable radiator, and a limiting rope is arranged between the fixed radiator and the movable radiator.

[0013] As a preferred closed substation based on fire protection large-scale power grid safety assurance of the present invention, the pressure plate is provided with a through hole, and the boom is provided with a waterproof power switch corresponding to the position of the through hole.

[0014] As a preferred closed substation based on fire protection large-scale power grid safety assurance of the present invention, the transformer box is made of aluminum alloy or stainless steel, and an inspection door corresponding to the transformer box is provided on the side of the transformer room.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention installs a closed transformer box in a transformer room, circulates and pumps cold water into the transformer room through a cooling tower, and utilizes the refrigerant in the cold water flow channel to directly exchange heat with the transformer box, thereby effectively taking away a large amount of heat generated during the operation of the transformer box, thereby maintaining the operating temperature of the equipment within a safe and controllable range. This design solves the problem of low heat dissipation efficiency of traditional closed transformer boxes. In particular, the temperature-sensitive telescopic rod in the heat dissipation mechanism can automatically adjust the position of the movable radiator according to the dynamic changes in the internal temperature of the transformer box, thereby flexibly adjusting the heat dissipation area, which not only ensures the maximization of the heat dissipation efficiency, but also avoids the influence of excessive heating of the coolant on the subsequent cooling effect of the transformer box, thereby achieving more refined and efficient thermal management.

[0016] 2. The present invention integrates a fire-fighting mechanism on one side of the transformer box to ensure a rapid response when a fire is detected. The stop valve is opened by a temperature-sensitive telescopic rod. The design of the stop valve prevents fire-fighting water from accidentally entering the transformer box under non-emergency conditions, thereby ensuring the normal operation of the equipment. When a fire occurs, the system can quickly open the valve mechanically to allow water to flow through the rotating nozzle and spray out evenly, thereby achieving a rapid fire-extinguishing effect. In addition, the fire-fighting mechanism does not need to rely on electricity to operate, and can still effectively suppress the spread of fire when the power is cut off, thereby enhancing the emergency response capability and safety of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the cross-section mechanism of the present invention; Figure 2 It is a schematic diagram of the overall structure of the present invention; Figure 3 It is a front view of the present invention; Figure 4 For the present invention Figure 3 Middle AA section; Figure 5 It is a structural schematic diagram of the transformer box, the heat dissipation mechanism and the fire fighting mechanism in the first perspective of the present invention; Figure 6 It is a front cross-sectional view of the transformer box of the present invention in cooperation with the heat dissipation mechanism and the fire fighting mechanism; Figure 7 For the present invention Figure 6 Middle CC section; Figure 8 It is a structural schematic diagram of the transformer box, the heat dissipation mechanism and the fire fighting mechanism in the second viewing angle of the present invention; Fig. 9 For the present invention Figure 6 Enlarged view of point B in the middle; Fig.10 For the present invention Figure 6 Enlarged view of point D in the middle; Fig.11 For the present invention Figure 8 Enlarged view of point F in the middle; Fig.12 For the present invention Figure 7 Enlarged view of point E in the middle; Fig.13 It is a schematic diagram of the structure of the temperature-sensitive telescopic rod of the present invention.

[0018] In the figure: 1, substation; 101, inspection door; 102, cold water flow channel; 2, cold water tower; 201, tower body; 202, water outlet pipe; 203, circulation pump; 204, return pipe; 205, refrigerator; 3, substation box; 301, threading hole; 302, slide rail; 4, heat dissipation mechanism; 401, fixed radiator; 4011, first heat dissipation tooth plate; 402, movable radiator; 4021, second heat dissipation tooth plate; 4022, slider; 403, temperature sensing telescopic rod; 4031, piston rod; 4032, temperature sensing tube; 40321, sleeve; 40322, connecting pipe; 4 0323, liquid storage tube; 4033, reflective cover; 40341, fixing ring; 404, limit rope; 5, fire-fighting mechanism; 501, siphon; 502, stop valve; 5021, valve housing; 50211, sealing seat; 5022, valve stem; 50221, limit flange; 5023, spring; 503, limit plate; 5031, pressure plate; 5032, through hole; 5033, hanging arm; 5034, sensor arm; 504, rotating nozzle; 5041, spiral spray hole; 5042, upper spray hole; 505, support frame; 5051, slot; 506, waterproof power switch. DETAILED DESCRIPTION

[0019] See also Figure 1-Figure 13 , a closed substation based on fire protection large-scale power grid safety protection, including a substation room 1 and a substation box 3, and also including a cooling tower 2, the front and rear sides of the substation box 3 are provided with a heat dissipation mechanism 4, and the side end surface of the substation box 3 is provided with a fire protection mechanism 5; The transformer box 3 is evenly installed in the transformer room 1. A threading hole 301 is provided on the top of the transformer box 3. A sealing ring is provided in the threading hole 301. A cold water flow channel 102 is formed between the transformer box 3 and the transformer room 1. The cold water tower 2 includes a tower body 201, a water outlet pipe 202, a return pipe 204 and a refrigerator 205. The tower body 201 is connected to the cold water flow channel 102 through the water outlet pipe 202 and the return pipe 204. A circulating pump 203 is provided on the water outlet pipe 202. The heat dissipation mechanism 4 includes a fixed heat sink 401, a movable heat sink 402 and a temperature-sensitive telescopic rod 403. The movable heat sink 402 is slidably connected to the fixed heat sink 401 through the temperature-sensitive telescopic rod 403. The fire-fighting mechanism 5 includes a siphon 501 , a stop valve 502 , a limit plate 503 and a rotating nozzle 504 . The stop valve 502 and the rotating nozzle 504 are installed on the siphon 501 . The limit plate 503 is movably installed on the transformer box 3 to limit the opening of the stop valve 502 .

[0020] Furthermore, the transformer boxes 3 are alternately installed on the left and right sides in the transformer room 1, the cold water channel 102 contacts the front end face, the left end face and the rear end face of the transformer box 3, the fixed radiator 401 is fixedly installed on the transformer box 3, the upper end face of the fixed radiator 401 is provided with a first heat dissipation tooth plate 4011, the front end face and the rear end face of the transformer box 3 are provided with a slide rail 302, the back side of the movable radiator 402 is provided with a slider 4022 cooperating with the slide rail 302, and the lower end face of the movable radiator 402 is provided with a second heat dissipation tooth plate 4021 which is staggered and meshed with the first heat dissipation tooth plate 4011.

[0021] By moving the movable radiator 402 up and down, the contact area between the first heat dissipation tooth plate 4011 and the second heat dissipation tooth plate 4021 and the coolant is changed, thereby changing the heat dissipation area of ​​the distribution box, so that the front-end transformer box 3 is in a suitable working state, and the coolant will not heat up too quickly to affect the heat dissipation of the rear-end transformer box 3.

[0022] Furthermore, the temperature-sensing telescopic rod 403 includes a temperature-sensing tube 4032 and a piston rod 4031. The temperature-sensing tube 4032 includes a sleeve 40321, a connecting pipe 40322 and a liquid storage tube 40323. The liquid storage tube 40323 is installed on the inner end surface of the transformer box 3, and the sleeve 40321 is installed on the outer end surface of the transformer box 3. The sleeve 40321 and the bottom of the transformer box 3 are connected through the connecting pipe 40322. The piston rod 4031 is inserted into the sleeve 40321 and is slidably connected thereto. Kerosene is provided in the temperature-sensing tube 4032. The top of the piston rod 4031 is fixedly connected to the top lower end surface of the movable radiator 402.

[0023] The kerosene in the temperature sensing tube 4032 expands as the temperature in the transformer box 3 rises, causing the piston rod 4031 to slide upward, pushing up the movable radiator 402, thereby separating the first heat dissipation tooth plate 4011 from the second heat dissipation tooth plate 4021, increasing the contact area between the fixed radiator 401 and the movable radiator 402 and the coolant, improving the heat dissipation efficiency of the transformer box 3, and realizing adaptive adjustment of the radiator with the temperature of the transformer box 3.

[0024] Furthermore, the inner diameter of the sleeve 40321 is one fifth of the inner diameter of the temperature sensing tube 4032 , and the temperature sensing telescopic rod 403 is made of stainless steel.

[0025] The thick temperature sensing tube 4032 cooperates with the thinner sleeve 40321 structure, so that the kerosene in the temperature sensing tube 4032 expands slightly, which can cause a larger stroke change of the piston rod 4031 in the sleeve 40321, making the movable radiator 402 more sensitive to response.

[0026] Furthermore, a reflective cover 4033 is provided near the transformer side of the temperature sensing tube 4032, and fixing rings 40341 ​​fixed to the temperature sensing tube 4032 are provided at the top and bottom of the reflective cover 4033. The reflective cover 4033 is made of a mirror metal plate and has an arc-shaped structure.

[0027] When a fire occurs in the transformer box 3, the reflective cover 4033 can reflect the heat radiation generated by the fire to the temperature sensing tube 4032, so that the temperature sensing telescopic rod 403 can quickly heat up to respond, and the piston rod 4031 slides upward to trigger the fire fighting mechanism 5, quickly extinguishing the fire to prevent the fire from further spreading.

[0028] Furthermore, the stop valve 502 includes a valve housing 5021, a valve stem 5022 and a spring 5023. A sealing seat 50211 is arranged in the valve housing 5021. The spring 5023 is sleeved on the valve stem 5022. The valve stem 5022 is elastically slidably connected to the valve housing 5021 through the spring 5023. A limiting flange 50221 for limiting the spring 5023 is arranged on the valve stem 5022.

[0029] The valve stem 5022 is moved away from the sealing seat 50211 by the action of the spring 5023, so that the stop valve 502 remains in an open state. Pressing the valve stem 5022 downward will press the valve stem 5022 against the sealing seat 50211, so that the stop valve 502 cuts off the water flow in the siphon tube 501, preventing water from entering the transformer box 3 during daily use.

[0030] Furthermore, the siphon tube 501 is an "n"-shaped pipe, the height of the coolant overflows the siphon tube 501, the stop valve 502 is installed on the outside, the rotary nozzle 504 is installed at the end of the siphon tube 501 and is rotatably connected thereto, a spiral spray hole 5041 is provided on the side of the rotary nozzle 504, an upper spray hole 5042 is provided on the upper end face of the rotary nozzle 504, a support frame 505 is provided on the side end face of the transformer box 3, a slot 5051 is provided on the support frame 505, a limit plate 503 is inserted into the slot 5051 and is slidably connected to the support frame 505, the limit plate 503 includes a pressure plate 5031, a sensing arm 5034 and a suspension arm 5033, the spacing between the pressure plate 5031 and the sealing seat 50211 is equal to the length of the valve stem 5022, and the pressure plate 5031 squeezes the valve stem 5022 so that it maintains close contact with the sealing seat 50211.

[0031] The pressure plate 5031 blocks the rebound of the valve stem 5022, so that the stop valve 502 remains sealed during daily use of the transformer box 3. When a fire occurs, the pressure plate 5031 is pulled out, so that the valve stem 5022 rebounds under the action of the spring 5023, and the water flows into the transformer box 3 under the siphon effect, and is sprayed out by the rotating nozzle 504 to extinguish the fire. During the spraying process, the spiral spray hole 5041 on the side of the rotating nozzle 504 drives the rotating nozzle 504 to rotate due to the reaction force of the water flow, and the upper spray hole 5042 on the top can increase the spraying height and coverage range.

[0032] Furthermore, the sensing arm 5034 is located at the upper end of the movable radiator 402 , and a limit rope 404 is provided between the fixed radiator 401 and the movable radiator 402 .

[0033] When the equipment in the transformer box 3 is working normally, its temperature is usually within fifty degrees. The temperature-sensitive telescopic rod 403 is usually extended and retracted within a smaller range. The sliding stroke of the temperature-sensitive telescopic rod 403 is limited by the limit rope 404 to prevent it from triggering the fire-fighting mechanism 5 during normal operation. When a fire occurs in the transformer box 3, the temperature rises rapidly, causing the kerosene in the temperature-sensitive telescopic rod 403 to gasify. The piston rod 4031 breaks the limit rope 404 under the action of strong pressure, hits the sensing arm 5034, and opens the stop valve 502, so that cooling water is sprayed into the transformer box 3 to extinguish the fire, thereby controlling the fire in a single transformer box 3 and reducing losses.

[0034] Furthermore, a through hole 5032 is provided on the pressing plate 5031 , and a waterproof power switch 506 corresponding to the position of the through hole 5032 is provided on the suspension arm 5033 .

[0035] When the pressure plate 5031 slides upward, the valve stem 5022 of the stop valve 502 is inserted into the through hole 5032 under the reset action of the spring 5023, hitting the waterproof power switch 506 on the boom 5033, cutting off the power supply in the transformer box 3 to prevent the rescuers from electric shock accidents.

[0036] Furthermore, the transformer box 3 is made of aluminum alloy or stainless steel, and an inspection door 101 corresponding to the transformer box 3 is provided on the side of the transformer room 1 .

[0037] Stainless steel and aluminum alloy materials have good corrosion resistance and high thermal conductivity, and can maintain good heat dissipation efficiency. An inspection door 101 is set on the side of the substation room 1 to facilitate maintenance personnel to carry out maintenance in daily work.

[0038] When the device is in use, the transformer box 3 is evenly installed in the transformer room 1 according to the predetermined design scheme, ensuring that an effective cold water flow channel 102 is formed between each transformer box 3, installing the cold water tower 2 and ensuring that the pipe connection between it and the cold water flow channel 102 is correct, and a circulation pump 203 needs to be installed on the outlet pipe 202 to drive the cold water to flow, and the circulation pump 203 on the cold water tower 2 is started to make the cold water circulate in the cold water flow channel 102 to take away the heat of the transformer box 3, and the cold water must overflow the siphon pipe 501 to ensure that it can produce a siphon phenomenon when extinguishing a fire. During daily use, the kerosene in the temperature sensing tube 4032 expands as the temperature in the transformer box 3 increases, so that the piston rod 4031 slides upward, and the movable radiator 402 is lifted upward, so that the first heat dissipation tooth plate 4011 is separated from the second heat dissipation tooth plate 4021, thereby increasing the contact area between the fixed radiator 401 and the movable radiator 402 and the coolant, and improving the transformer The heat dissipation efficiency of the electric box 3 is improved, and the radiator is adaptively adjusted with the temperature of the electric box 3. When a fire is detected, the reflective cover 4033 reflects the heat radiation to the temperature-sensitive telescopic rod 403, causing the piston rod 4031 to rise. The piston rod 4031 rises and pulls the limit rope 404 at the same time, causing the limit rope 404 to break. The piston rod 4031 hits the sensing arm 5034, so that the stop valve 502 is opened, and cold water is sprayed out from the rotating nozzle 504 through the siphon 501 to implement the fire extinguishing operation. When the pressure plate 5031 slides upward, the valve stem 5022 is inserted into the through hole 5032 and hits the waterproof power switch 506 on the boom 5033 to cut off the power supply to prevent electric shock accidents. After the fire is extinguished, the damaged equipment needs to be evaluated and repaired, the fire fighting mechanism 5 needs to be reconfigured, and the entire system needs to be fully inspected. The equipment can effectively limit the fire in the substation room 1 to a single substation box 3, thereby reducing the property loss caused by the fire.

[0039] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A closed substation based on fire protection and large-scale power grid security, comprising a substation room (1) and a substation box (3), characterized in that: It also includes a cooling water tower (2), a heat dissipation mechanism (4) is provided on the front and rear sides of the transformer box (3), and a fire protection mechanism (5) is provided on the side end surface of the transformer box (3); The transformer boxes (3) are evenly installed in the transformer room (1); a cold water flow channel (102) is formed between the transformer boxes (3) and the transformer room (1); the cold water tower (2) comprises a tower body (201), a water outlet pipe (202), a return pipe (204) and a refrigerator (205); the tower body (201) is connected to the cold water flow channel (102) via the water outlet pipe (202) and the return pipe (204); a circulating pump (203) is provided on the water outlet pipe (202); The heat dissipation mechanism (4) comprises a fixed heat sink (401), a movable heat sink (402) and a temperature-sensing telescopic rod (403); the movable heat sink (402) is slidably connected to the fixed heat sink (401) via the temperature-sensing telescopic rod (403); The fire-fighting mechanism (5) comprises a siphon tube (501), a stop valve (502), a limit plate (503) and a rotating nozzle (504); the stop valve (502) and the rotating nozzle (504) are mounted on the siphon tube (501); and the limit plate (503) is movably mounted on the transformer box (3) to limit the opening of the stop valve (502).

2. A closed substation based on fire protection and large-scale power grid security as claimed in claim 1, characterized in that: The fixed radiator (401) is fixedly mounted on the transformer box (3); the upper end surface of the fixed radiator (401) is provided with a first heat dissipation tooth plate (4011); the front end surface and the rear end surface of the transformer box (3) are provided with slide rails (302); the back surface of the movable radiator (402) is provided with a slider (4022) that cooperates with the slide rail (302); and the lower end surface of the movable radiator (402) is provided with a second heat dissipation tooth plate (4021) that is staggered and meshed with the first heat dissipation tooth plate (4011).

3. A closed substation based on fire protection and large-scale power grid security as claimed in claim 1, characterized in that: The temperature-sensitive telescopic rod (403) comprises a temperature-sensitive tube (4032) and a piston rod (4031). The temperature-sensitive tube (4032) comprises a sleeve (40321), a connecting pipe (40322) and a liquid storage pipe (40323). The liquid storage pipe (40323) is mounted on the inner end surface of the transformer box (3). The sleeve (40321) is mounted on the outer end surface of the transformer box (3). The sleeve (40321) and the bottom of the transformer box (3) are connected through the connecting pipe (40322). The piston rod (4031) is inserted into the sleeve (40321) and is slidably connected thereto. Kerosene is provided in the temperature-sensitive tube (4032). The top of the piston rod (4031) is fixedly connected to the top lower end surface of the movable radiator (402).

4. A closed substation based on fire protection and large-scale power grid security as claimed in claim 3, characterized in that: The inner diameter of the sleeve (40321) is one fifth of the inner diameter of the temperature sensing tube (4032), and the temperature sensing telescopic rod (403) is made of stainless steel.

5. The closed substation based on fire protection large-scale power grid security as claimed in claim 1, characterized in that: The stop valve (502) comprises a valve housing (5021), a valve stem (5022) and a spring (5023); a sealing seat (50211) is provided in the valve housing (5021); the spring (5023) is sleeved on the valve stem (5022); the valve stem (5022) is elastically slidably connected to the valve housing (5021) via the spring (5023); and a limiting flange (50221) for limiting the spring (5023) is provided on the valve stem (5022).

6. A closed substation based on fire protection and large-scale power grid security as claimed in claim 5, characterized in that: The siphon pipe (501) is an "n"-shaped pipe, and the stop valve (502) is installed on the outside of the siphon pipe. The rotary nozzle (504) is installed at the end of the siphon pipe (501) and is rotatably connected thereto. The side of the rotary nozzle (504) is provided with a spiral spray hole (5041), and the upper end surface of the rotary nozzle (504) is provided with an upper spray hole (5042). The side end surface of the transformer box (3) is provided with a support frame (505), and the support frame (505) is provided with a slot (5051). The limit plate (503) is inserted into the slot (5051) and is slidably connected to the support frame (505). The limit plate (503) includes a pressure plate (5031), a sensing arm (5034) and a suspension arm (5033). The spacing between the pressure plate (5031) and the sealing seat (50211) is equal to the length of the valve stem (5022).

7. A closed substation based on fire protection and large-scale power grid security as claimed in claim 6, characterized in that: The sensing arm (5034) is located at the upper end of the movable radiator (402), and a limiting rope (404) is provided between the fixed radiator (401) and the movable radiator (402).

8. The closed substation based on fire protection and large-scale power grid security as claimed in claim 6, characterized in that: A through hole (5032) is provided on the pressing plate (5031), and a waterproof power switch (506) corresponding to the position of the through hole (5032) is provided on the suspension arm (5033).

9. The closed substation based on fire protection and large-scale power grid security as claimed in claim 1, characterized in that: The transformer box (3) is made of aluminum alloy or stainless steel, and a maintenance door (101) corresponding to the transformer box (3) is provided on the side of the transformer room (1).

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