Low-carbon and environment-friendly pre-containerized substation

Abstract

This invention relates to the field of substation technology, specifically a low-carbon and environmentally friendly prefabricated substation. It includes an outer shell structure composed of load-bearing columns and wall panels, and electrical equipment housed within the shell structure. The electrical equipment mainly includes a transformer and a high-voltage switchgear. The transformer uses natural ester insulating oil, achieving a first-class energy efficiency level. The high-voltage switchgear is an environmentally friendly switchgear, using dry air, nitrogen, or an environmentally friendly mixed gas instead of traditional SF6 gas. Fire extinguishing tubes are embedded within the wall panels. This invention integrates the switching device with the substation shell, adapting to AC transmission substations of 750 kV and above. It can automatically activate fire extinguishing in the event of a fire caused by an electrical fault, and senses the direction of the flame, directing the directional ball to spray the fire extinguishing medium towards one side of the flame, without requiring electrical control.

Description

Technical Field

[0001] This invention relates to the field of substation technology, specifically a low-carbon and environmentally friendly prefabricated substation. Background Technology

[0002] A prefabricated box-type substation is a compact, complete set of power distribution equipment that integrates high-voltage switchgear, distribution transformers, and low-voltage power distribution devices into one or more enclosures according to a certain wiring scheme. Among them, AC transmission substations of 750 kV and above have high voltage levels, and the risk of fire caused by electrical faults is even higher. The short-circuit capacity of AC transmission substations of 750 kV and above is extremely large, and the fault current can reach tens of thousands of amperes. Once a short circuit occurs, the arc temperature generated can reach tens of thousands of degrees Celsius. Therefore, in order to address the risk of fire caused by electrical faults in AC transmission substations of 750 kV and above, existing prefabricated box-type AC transmission substations of 750 kV and above are equipped with fire extinguishing equipment. For example, patent application CN215681515U discloses a box-type substation with a fire extinguishing device, which describes: the mounting cap is connected to the fire extinguishing device, and the mounting cap is equipped with a heat-sensitive glass. When a fire occurs, the heat-sensitive glass breaks, and the controller controls the solenoid valve to open, thereby spraying dry powder to effectively control the fire.

[0003] The aforementioned existing technologies can only spray fire extinguishing media indiscriminately over a large area into the substation, and cannot spray it in a directional manner according to the direction of the flames. Furthermore, since AC transmission substations of 750 kV and above are larger in scale and volume, this method of indiscriminately spraying fire extinguishing media has low fire extinguishing efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a low-carbon and environmentally friendly prefabricated substation that can automatically sense the direction of flames and spray extinguishing media in a directional manner, thereby improving fire extinguishing efficiency.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a low-carbon and environmentally friendly prefabricated substation, comprising an outer shell structure composed of load-bearing columns and wall panels, and electrical equipment installed within the outer shell structure. A fire extinguishing tube is embedded inside the wall panels, and the fire extinguishing tube contains a positive-pressure fire extinguishing medium. A connecting switch seat is provided on the inward-facing surface of the wall panels, and a diffuser plate is provided outside the connecting switch seat. An automatic switching structure is provided on the connecting switch seat and the diffuser plate. The connecting switch seat is connected to the fire extinguishing tube and is normally closed. When exposed to flame, the automatic switching structure switches the connecting switch seat to the connected state. A directional ball is provided at the inward-facing end of the connecting switch seat. When the connecting switch seat is switched to the connected state, the fire extinguishing medium in the fire extinguishing tube is sprayed out from the directional ball through the connecting switch seat. A thermal expansion rod is provided in the diffuser plate, and a spring-loaded traction steering assembly is provided in the connecting switch seat. The thermal expansion rod and the spring-loaded traction steering assembly cooperate to control the angle deflection of the directional ball, causing the directional ball to spray the fire extinguishing medium towards the heat source.

[0006] The elastic traction steering component and the thermal expansion rod are in one-to-one correspondence, and both are evenly distributed in a circular array with the steering ball as the center.

[0007] The elastic traction steering assembly includes a side groove, a support shaft, and an extended rocker arm. The side groove is formed on the connecting switch seat, the support shaft is fixedly installed inside the side groove, and the extended rocker arm rotates around the support shaft. One end of the extended rocker arm is connected to an elastic rib, and the other end of the elastic rib is fixed to the steering ball. The other end of the extended rocker arm is in contact with a thermal expansion rod. When the thermal expansion rod expands and elongates due to heat, it will press against the extended rocker arm, causing the extended rocker arm to pull the elastic rib and drive the steering ball to deflect in the direction of the heated thermal expansion rod.

[0008] The length of the lever arm on the side where the expanded seesaw connects to the elastic rib is greater than the length of the lever arm on the side where the expanded seesaw contacts the thermal expansion rod.

[0009] The surface of the diffuser plate is provided with a push rod groove, and the thermal expansion push rod is limited and disposed in the push rod groove.

[0010] The internal part of the combined switch base is provided with a limiting groove, which is evenly distributed in a circular array with the direction ball as the center; a locking rod is inserted in the limiting groove, and a pressure ring is fixedly provided on the locking rod. A first elastic member is provided on one side of the pressure ring. The first elastic member applies elastic force to the pressure ring, so that the locking rod has a tendency to move towards the direction ball.

[0011] The interior of the connecting switch base is provided with a track groove, in which a sliding pressure block is slidably installed. The sliding pressure block can only slide parallel to the axial direction of the connecting switch base. A second elastic element is provided on one side of the sliding pressure block. When the sliding pressure block rigidly blocks the end of the locking rod, the other end of the locking rod abuts against the directional ball, limiting the directional ball and maintaining a sealed contact between the directional ball and the connecting switch base.

[0012] A drooping lever is fixedly installed on the expansion rocker. When the thermal expansion rod expands and elongates due to heat, driving the expansion rocker to rotate, it will cause the drooping lever to move, so that the drooping lever drives the sliding pressure block to compress the second elastic member, and the end of the locking rod loses its rigid limit. When all the thermal expansion rods expand and elongate due to heat, the directional ball separates from the coupling switch seat under the pressure of the fire extinguishing medium, and the fire extinguishing medium will be sprayed out from the gap between the directional ball and the coupling switch seat.

[0013] The automatic switch structure includes a ring and a sealing piston. The ring is fixed inside the connecting switch base, and the sealing piston is disposed on one side of the ring. A connecting frame is fixedly disposed on the sealing piston, and a frame ring is fixedly disposed on the connecting frame. A double-wall corrugated sleeve is disposed on one side of the frame ring, and the double-wall corrugated sleeve applies pressure to the frame ring, so that the sealing piston and the ring make sealing contact.

[0014] The internal structure of the combined switch base and diffuser plate has a medium flow channel. The surface of the diffuser plate is provided with a thermal burst shroud. One end of the medium flow channel is connected to the thermal burst shroud, and the other end is connected to the double-walled corrugated sleeve. The medium flow channel, the thermal burst shroud, and the double-walled corrugated sleeve are all filled with an incompressible medium. The pressure of the incompressible medium keeps the double-walled corrugated sleeve in an extended state, applying pressure to the frame ring. The medium flow channel and the thermal burst shroud are uniformly distributed in a circumferential array with the directional ball as the center. The thermal burst shroud will crack under flame burning.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The substation of this invention integrates the switching device with the substation casing through a combination of switch base, directional ball, and thermal expansion rod. It can automatically activate fire extinguishing in the event of a fire caused by an electrical fault, and sense the direction of the flames, causing the directional ball to spray the fire extinguishing medium towards one side of the flames. It does not require electrical control, and the precise orientation can reduce the number of switching devices. It is suitable for AC transmission substations of 750 kV and above, and improves the safety of the substation by timely directional fire extinguishing.

[0016] 2. The present invention, through the combination of the locking rod, the drooping part and the directional ball, can automatically unlock the directional ball when the flame covers the entire thermal expansion rod, so that the fire extinguishing medium can be sprayed out from the gap between the directional ball and the connecting switch seat. At this time, there is no need to distinguish the direction of the flame, and the fire extinguishing medium is sprayed to the maximum extent to achieve automatic switching of different working conditions. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0018] Figure 2 This is a schematic diagram of the wall panel of the present invention.

[0019] Figure 3 This is a front view of the wall panel of the present invention.

[0020] Figure 4 for Figure 3 Cross-sectional view at point AA.

[0021] Figure 5 This is a cross-sectional view of the switch base.

[0022] Figure 6 for Figure 3 Cross-sectional view at point BB.

[0023] Figure 7 This is a three-dimensional half-section view of the switch base.

[0024] Figure 8 This is a magnified partial 3D section view of the switch base.

[0025] Figure 9 This is a three-dimensional half-section view of the switch base at a horizontal angle.

[0026] Figure 10 This is a magnified partial view of the horizontal angle half-section of the switch base.

[0027] Figure 11 This is a schematic diagram of the back structure of the diffuser plate and the combined switch base of the present invention.

[0028] In the diagram: 1. Load-bearing column; 2. Wall panel; 3. Fire extinguishing pipe; 4. Connecting switch base; 5. Diffuser plate; 6. Directional ball; 7. Thermal expansion rod; 201. Metal outer layer; 202. Environmentally friendly filler layer; 401. Side groove; 402. Support shaft part; 403. Expanding seesaw; 404. Elastic rib; 405. Limiting through groove; 406. Locking rod; 407. Pressure ring part; 408. First elastic element; 409. Track groove; 410. Sliding pressure block; 411. Second elastic element; 412. Drooping part; 413. Ring; 414. Sealing piston; 415. Connecting frame; 416. Frame ring part; 417. Double wall corrugated sleeve; 418. Medium flow channel; 501, Top rod groove; 502, Hot blast cover; 503, Rotary locking recess; 601, Jet flow channel; 602, Sealing ring. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Please see Figures 1 to 11 This invention provides a technical solution: a low-carbon and environmentally friendly prefabricated substation, designed to address the risk of fire caused by electrical faults in 750 kV and above AC transmission substations. Through structural design, it automatically senses the direction of flames and sprays extinguishing media in a directional manner, thereby improving fire extinguishing efficiency. Specific embodiments are as follows: This prefabricated substation consists of an outer shell structure formed by load-bearing columns 1 and wall panels 2. Electrical equipment is housed within this shell structure, primarily including transformers and high-voltage switchgear. The transformers utilize natural ester insulating oil, achieving a Class I energy efficiency rating. The high-voltage switchgear is environmentally friendly, using dry air, nitrogen, or an environmentally friendly mixed gas instead of traditional SF6 gas. (See also...) Figure 2 As shown, the wall panel 2 of the present invention adopts a three-layer structure design, namely a metal outer layer 201, an environmentally friendly filling layer 202 and a metal outer layer 201, that is, the innermost and outermost layers are both metal outer layers 201, and the middle layer is filled with an environmentally friendly filling layer 202. The environmentally friendly filling layer 202 is made of environmentally friendly non-metallic material, preferably lightweight concrete, and the raw materials include cement, water and various solid wastes, which is more low-carbon and environmentally friendly.

[0031] The wall panel 2 is equipped with a fire extinguishing pipe 3, which contains a positive pressure fire extinguishing medium. Specifically, the substation of this invention is also equipped with a fire extinguishing medium tank, and the fire extinguishing pipe 3 is connected to the fire extinguishing medium tank. The fire extinguishing medium can be dry powder or liquid carbon dioxide.

[0032] A connecting switch base 4 is provided on the inward-facing surface of wall panel 2. The connecting switch base 4 is connected to the fire extinguishing pipe 3. For details, please refer to [link / reference]. Figure 5 As shown, the connecting switch base 4 is provided with a threaded interface, and the fire extinguishing tube 3 is provided with a threaded hole. The connecting switch base 4 is sealed and connected to the threaded hole on the fire extinguishing tube 3 through the threaded interface. A diffuser plate 5 is provided on the outside of the connecting switch base 4. (See reference...) Figure 2 As shown, a rotating recess 503 is provided at the edge of the surface of the diffuser plate 5. By clamping the tool in the rotating recess 503, the diffuser plate 5 and the connecting switch base 4 can be rotated, thereby facilitating the installation and disassembly of the device of the present invention.

[0033] An automatic switching structure is provided on the combination switch base 4 and the diffuser plate 5. When the combination switch base 4 is normally closed, the automatic switching structure switches it to the open state after being exposed to flame. A directional ball 6 is provided at the inward-facing end of the combination switch base 4. When the combination switch base 4 is switched to the open state, the extinguishing medium in the fire extinguishing tube 3 is sprayed out through the combination switch base 4 and from the directional ball 6. (See reference...) Figure 8 and Figure 10 As shown, the end slot of the connecting switch base 4 is truncated into a frustum shape, and a sealing ring 602 is embedded in the inner wall of the frustum-shaped end slot. The directional ball 6 of the present invention achieves sealed contact with the connecting switch base 4 through the sealing ring 602. A spray channel 601 is provided through the directional ball 6 of the present invention, and the fire extinguishing medium is sprayed outward through the spray channel 601, so that the spray direction of the fire extinguishing medium can be adjusted when the directional ball 6 deflects.

[0034] The diffuser plate 5 is equipped with a thermal expansion rod 7, which is made of a material with a large coefficient of thermal expansion and contraction, such as aluminum. The thermal expansion rod 7 has sufficient length and is combined with the elastic traction steering component in the switch base 4. Through the cooperation of the thermal expansion rod 7 and the elastic traction steering component, the angle of the directional ball 6 is controlled, so that the directional ball 6 sprays the fire extinguishing medium toward the heat source.

[0035] The elastic traction steering assembly and the thermal expansion rod 7 are in one-to-one correspondence, and both are evenly distributed in a circular array with the steering ball 6 as the center.

[0036] The elastic traction steering assembly includes a side groove 401, a support shaft 402, and an extended rocker 403. The side groove 401 is formed on the connecting switch seat 4, the support shaft 402 is fixedly installed inside the side groove 401, and the extended rocker 403 rotates around the support shaft 402. One end of the extended rocker 403 is connected to an elastic rib 404, and the other end of the elastic rib 404 is fixed to the steering ball 6. The elastic rib 404 is made of high-temperature resistant steel wire and can be elastically stretched. Since the elastic ribs 404 are concentrated on the steering ball 6 and are close together, their working temperature is basically the same.

[0037] The other end of the expansion seesaw 403 is in contact with the thermal expansion rod 7. When the thermal expansion rod 7 is heated and expands, it will push against the expansion seesaw 403, causing the expansion seesaw 403 to pull the elastic rib 404 and drive the directional ball 6 to deflect in the direction of the heated thermal expansion rod 7.

[0038] The lever arm length on the side where the extended seesaw 403 connects to the elastic rib 404 is greater than the lever arm length on the side where the extended seesaw 403 contacts the thermal expansion rod 7. (See reference...) Figure 5 As shown, by setting the lever arm of the expansion seesaw 403, the thermal expansion rod 7 only needs to extend by a short distance to make the elastic rib 404 subject to a greater traction, thus achieving the effect of expanding the amplitude.

[0039] The surface of the diffuser plate 5 is provided with a push rod groove 501, and the thermal expansion push rod 7 is limited and disposed in the push rod groove 501.

[0040] A limiting groove 405 is provided inside the switch base 4. The limiting groove 405 is evenly distributed in a circular array with the direction ball 6 as the center. A locking rod 406 is inserted in the limiting groove 405. A pressure ring part 407 is fixedly provided on the locking rod 406. A first elastic member 408 is provided on one side of the pressure ring part 407. The first elastic member 408 is a spring. The first elastic member 408 applies elastic force to the pressure ring part 407, so that the locking rod 406 has a tendency to move towards the direction ball 6.

[0041] The interior of the switch base 4 is provided with a track groove 409, and a sliding block 410 is slidably installed in the track groove 409. The sliding block 410 can only slide parallel to the axial direction of the switch base 4. A second elastic element 411 is provided on one side of the sliding block 410. The second elastic element 411 is a spring.

[0042] When the sliding block 410 rigidly blocks the end of the locking rod 406, the other end of the locking rod 406 presses against the directional ball 6, limiting the directional ball 6 and maintaining a sealed contact between the directional ball 6 and the engagement switch seat 4.

[0043] A drooping lever 412 is fixedly installed on the expansion rocker 403. When the thermal expansion rod 7 expands and elongates due to heat, driving the expansion rocker 403 to rotate, it will drive the drooping lever 412 to move, causing the drooping lever 412 to drive the sliding pressure block 410 to compress the second elastic member 411, and the end of the locking ball rod 406 loses its rigid limit. When all the thermal expansion rods 7 expand and elongate due to heat, the directional ball 6 separates from the connecting switch seat 4 under the pressure of the fire extinguishing medium, and the fire extinguishing medium will be sprayed out from the gap between the directional ball 6 and the connecting switch seat 4.

[0044] The automatic switch structure includes a ring 413 and a blocking piston 414. The ring 413 is fixed inside the connecting switch base 4, and the blocking piston 414 is disposed on one side of the ring 413. A connecting frame 415 is fixedly installed on the sealing piston 414, and a ring portion 416 is fixedly installed on the connecting frame 415. A double-walled corrugated sleeve 417 is provided on one side of the ring portion 416. The double-walled corrugated sleeve 417 is made of a double-layered corrugated sleeve with inner and outer sleeves. The double-walled corrugated sleeve 417 is made of metal. When the double-walled corrugated sleeve 417 is under positive pressure, it can apply axial pressure. When the internal positive pressure is lost, it can be compressed axially. The double-walled corrugated sleeve 417 applies pressure to the ring portion 416, so that the sealing piston 414 and the ring 413 make sealing contact.

[0045] A medium flow channel 418 is provided inside the switch base 4 and the diffuser plate 5. A heat blast shroud 502 is provided on the surface of the diffuser plate 5. One end of the medium flow channel 418 is connected to the heat blast shroud 502, and the other end is connected to the double-wall corrugated sleeve 417. The medium flow channel 418, the heat blast shroud 502 and the double-wall corrugated sleeve 417 are all filled with an incompressible medium, which can be water or flame-retardant hydraulic oil. The pressure of the incompressible medium keeps the double-wall corrugated sleeve 417 in an extended state and applies pressure to the ring portion 416. The medium flow channel 418 and the heat blast shroud 502 are evenly distributed in a circumferential array with the directional ball 6 as the center. The heat blast shroud 502 will crack under flame burning.

[0046] In the first embodiment, the thermal blasting shroud 502 is made of soda-lime glass, which has a large coefficient of thermal expansion and very weak resistance to rapid heating and cooling. It is prone to cracking when in contact with an open flame, releasing incompressible media.

[0047] In the second embodiment, the thermal blasting shroud 502 is made of plastic and melts upon contact with the high temperature of an open flame, releasing an incompressible medium.

[0048] The prefabricated box-type substation of the present invention is equipped with a positive pressure fire extinguishing medium tank, and the fire extinguishing tube 3 is connected to the fire extinguishing medium tank, so that the interior of the fire extinguishing tube 3 is filled with positive pressure fire extinguishing medium.

[0049] Initially, such as Figure 9 and Figure 10 As shown, the interiors of the thermal blasting shroud 502, the medium flow channel 418, and the double-wall corrugated sleeve 417 are all filled with incompressible medium. The pressure of the incompressible medium keeps the double-wall corrugated sleeve 417 in an ejected state. The connecting bracket 415 makes the sealing piston 414 and the annulus 413 in sealed contact. At this time, the connecting switch seat 4 is in a normally closed state.

[0050] When a fire breaks out in the substation, the flames come into contact with the thermal blast shield 502, causing it to rupture and leak the incompressible medium along the aforementioned path. The double-walled corrugated sleeve 417 loses pressure, and the positive-pressure extinguishing medium in the fire extinguishing insert 3 pushes open the sealing piston 414, entering the coupling switch base 4, in conjunction with reference... Figure 8 As shown in the figure, the extinguishing medium is sprayed out through the spray channel 601.

[0051] When the heat source is on one side of the directional ball 6, the temperature of the thermal expansion rod 7 on that side will be higher. The thermal expansion rod 7 exhibits the property of thermal expansion and contraction; when the temperature of the thermal expansion rod 7 is higher, it will thermally expand and elongate. (Refer to...) Figure 8 As shown, the thermal expansion rod 7 presses against the expansion seesaw 403, causing the expansion seesaw 403 to rotate. The expansion seesaw 403 amplifies the elongation of the thermal expansion rod 7, allowing the expansion seesaw 403 to exert a greater pull on the elastic rib 404.

[0052] Through the aforementioned traction, the directional ball 6 deflects towards the side of the fire source, directionally spraying the extinguishing medium without the need for electrical control.

[0053] See Figure 8 As shown, the directional ball 6 is held at the end of the engagement switch seat 4 by the end-limiting of the locking rod 406, and is in sealed contact with the engagement switch seat 4. When the initial thermal expansion rod 7 has not expanded due to heat, the expansion rocker 403 does not rotate, and the sliding block 410 just stops at the other end of the locking rod 406, rigidly blocking the other end of the locking rod 406. At this time, the locking rod 406 cannot move axially, so the directional ball 6 is rigidly limited at the end of the engagement switch seat 4 and can only be rotated for adjustment.

[0054] When the thermal expansion rod 7 expands due to heat, the expansion rocker 403 rotates, causing the drooping lever 412 to rotate. The drooping lever 412 then moves the sliding block 410, causing it to slide along the track groove 409 and compress the second elastic member 411 until the sliding block 410 moves away from the end position of the locking rod 406. At this point, the locking rod 406 loses the rigid obstruction of the sliding block 410 and can move axially.

[0055] When the flame completely covers all the thermal expansion rods 7, all the thermal expansion rods 7 expand due to heat, and all the corresponding locking rods 406 are unlocked, allowing axial movement. At this time, under the pressure of the extinguishing medium, the directional ball 6 will move away from the engagement switch seat 4, and the directional ball 6 will no longer be in contact with the sealing ring 602. The extinguishing medium is now sprayed not only from the spray channel 601, but also in large quantities from the gap between the directional ball 6 and the engagement switch seat 4. Since the flame covers all the thermal expansion rods 7 at this time, there is no need to distinguish the extinguishing direction, and the extinguishing medium is sprayed directly to the maximum extent, realizing automatic switching between different working conditions.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A low-carbon, environmentally friendly prefabricated substation, comprising an outer shell structure consisting of load-bearing columns and wall panels, and electrical equipment installed within the outer shell structure, characterized in that: The wall panel is equipped with a fire extinguishing tube, which contains a positive-pressure fire extinguishing medium. A connecting switch seat is provided on the inward side surface of the wall panel, and a diffuser plate is provided on the outside of the connecting switch seat. An automatic switching structure is provided on the connecting switch seat and the diffuser plate. The connecting switch seat is connected to the fire extinguishing tube. The connecting switch seat is normally closed. After being burned by flames, the automatic switching structure causes the connecting switch seat to switch to the connected state. The inward-facing end of the connecting switch base is provided with a directional ball. When the connecting switch base is switched to the connected state, the extinguishing medium in the extinguishing tube is sprayed out from the directional ball through the connecting switch base. The diffuser plate is provided with a thermal expansion rod, and the connecting switch base is provided with a spring traction steering assembly. The thermal expansion rod and the spring traction steering assembly work together to control the angle deflection of the steering ball, so that the steering ball sprays the fire extinguishing medium toward the heat source.

2. The low-carbon and environmentally friendly prefabricated substation according to claim 1, characterized in that: The elastic traction steering component and the thermal expansion rod are in one-to-one correspondence, and both are evenly distributed in a circular array with the steering ball as the center.

3. The low-carbon and environmentally friendly prefabricated substation according to claim 1, characterized in that: The elastic traction steering assembly includes a side groove, a support shaft, and an extended rocker plate. The side groove is formed on the connecting switch seat, the support shaft is fixedly installed inside the side groove, and the extended rocker plate rotates around the support shaft. One end of the extended seesaw is connected to an elastic rib, and the other end of the elastic rib is fixed to the directional ball; The other end of the expansion seesaw is in contact with the thermal expansion rod. When the thermal expansion rod expands and elongates due to heat, it will press against the expansion seesaw, causing the expansion seesaw to pull the elastic ribs and drive the directional ball to deflect in the direction of the heated thermal expansion rod.

4. The low-carbon and environmentally friendly prefabricated substation according to claim 3, characterized in that: The length of the lever arm on the side where the expanded seesaw connects to the elastic rib is greater than the length of the lever arm on the side where the expanded seesaw contacts the thermal expansion rod.

5. The low-carbon and environmentally friendly prefabricated substation according to claim 3, characterized in that: The surface of the diffuser plate is provided with a push rod groove, and the thermal expansion push rod is limited and disposed in the push rod groove.

6. The low-carbon and environmentally friendly prefabricated substation according to claim 3, characterized in that: The interior of the combined switch base is provided with a limiting slot, and the limiting slot is evenly distributed in a circular array with the directional ball as the center. A locking rod is inserted into the limiting groove, and a pressure ring is fixedly provided on the locking rod. A first elastic member is provided on one side of the pressure ring. The first elastic member applies elastic force to the pressure ring, causing the locking rod to tend to move towards the ball.

7. The low-carbon and environmentally friendly prefabricated substation according to claim 6, characterized in that: The interior of the connecting switch base is provided with a track groove, and a sliding block is slidably installed in the track groove. The sliding block can only slide parallel to the axial direction of the connecting switch base, and a second elastic element is provided on one side of the sliding block. When the sliding block rigidly blocks the end of the locking lever, the other end of the locking lever rests against the directional ball, limiting the directional ball and maintaining a sealed contact between the directional ball and the engagement switch seat.

8. The low-carbon and environmentally friendly prefabricated substation according to claim 7, characterized in that: A drooping lever is fixedly installed on the expansion rocker. When the thermal expansion rod expands and elongates due to heat, driving the expansion rocker to rotate, it will cause the drooping lever to move, so that the drooping lever drives the sliding pressure block to compress the second elastic member, and the end of the locking rod loses its rigid limit. When all the thermal expansion rods expand and elongate due to heat, the directional ball separates from the coupling switch seat under the pressure of the fire extinguishing medium, and the fire extinguishing medium will be sprayed out from the gap between the directional ball and the coupling switch seat.

9. The low-carbon and environmentally friendly prefabricated substation according to claim 1, characterized in that: The automatic switch structure includes a ring and a blocking piston. The ring is fixed inside the connecting switch base, and the blocking piston is disposed on one side of the ring. A connecting frame is fixedly installed on the sealing piston, and a frame ring is fixedly installed on the connecting frame. A double-walled corrugated sleeve is provided on one side of the frame ring. The double-walled corrugated sleeve applies pressure to the frame ring, so that the sealing piston and the ring edge make sealing contact.

10. The low-carbon, environmentally friendly prefabricated substation according to claim 9, characterized in that: The internal structure of the combined switch base and the diffuser plate has a medium flow channel. The surface of the diffuser plate is provided with a heat blast hood. One end of the medium flow channel is connected to the heat blast hood, and the other end is connected to the double-wall corrugated sleeve. The medium flow channel, the heat blast hood, and the double-wall corrugated sleeve are all filled with an incompressible medium. The pressure of the incompressible medium keeps the double-wall corrugated sleeve in an extended state and applies pressure to the frame ring. The medium flow channel and the thermal explosion shroud are both uniformly distributed in a circular array with the directional ball as the center; the thermal explosion shroud will crack under flame burning.

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