A mine high-voltage safety power distribution cabinet and a use method thereof

Abstract

The present application relates to the high-voltage power grid industry field, especially to a mine-used high-voltage safety power distribution cabinet and a use method, which comprises a metal cabinet body, a metal cabinet door and a high-voltage switch live part installed in the metal cabinet body; the inside of the metal cabinet body is separated into a mutually independent equipment chamber and an insulation chamber by an insulation partition plate, and the high-voltage switch live part is installed in the inside of the insulation chamber. When the power distribution cabinet operates to generate heat to form a positive pressure in the cabinet, the positive pressure gas directly drives the sealing inner plate to slide along the guide slide rod to the cabinet door direction, simultaneously increases the compression amount and the sealing specific pressure of the elastic sealing gasket, and the outer edge of the sealing gasket can be embedded into the gap between the door joints after being extruded and deformed to further block the leakage passage. The higher the positive pressure in the cabinet is, the greater the compression amount of the sealing gasket and the depth of the embedded door joint are, and the sealing performance is adaptively enhanced with the increase of the equipment load, which offsets the sealing force attenuation problem caused by the positive pressure pushing and extruding the cabinet door.

Description

Technical Field

[0001] This invention relates to the field of high-voltage power grid industry, and in particular to a high-voltage safety distribution cabinet for mining and its usage method. Background Technology

[0002] With the accelerated construction of ultra-high voltage AC / DC hybrid power grids with 750 kV and 1000 kV AC grids as the backbone, my country has formed a cross-regional energy transmission pattern of "transmitting electricity from the west to the east and supplying electricity from the north to the south." As a core infrastructure of the national energy strategy, ensuring its safe and stable operation is the primary task in building a new power system and constructing a large-scale power grid security and defense system.

[0003] Against this backdrop, high-voltage switchgear installed at key nodes of 750 kV and above power transmission systems (such as hub substations, converter stations, and large energy base collection stations) undertakes the critical functions of power distribution, control, and protection. Its operational reliability is directly related to the safety and stability of the power grid. Mining metal-enclosed high-voltage switchgear is the core equipment of the underground power supply system. It integrates high-voltage switch components such as circuit breakers and busbars. It relies on a metal enclosure to achieve explosion-proof, dustproof, and electrical insulation protection. It undertakes the critical functions of underground power distribution, line control, and fault protection. Its operational reliability directly determines the safety and stability of the mine power supply system.

[0004] Currently, most high-voltage switchgear used in mining adopts a metal-enclosed cabinet structure. The cabinet door and the cabinet body are statically sealed by a single rubber sealing strip. The sealing pre-tightening force is only provided by the locking force of the door lock, which has obvious defects in adaptability to working conditions. After the equipment is put into operation, the internal high-voltage switching components continue to heat up, causing the gas inside the metal shell to expand and form positive pressure. The positive pressure pushes the cabinet door outward, resulting in a decrease in the compression of the sealing strip and a decrease in the sealing specific pressure. This can easily lead to gas leakage inside the cabinet, weakening the explosion-proof protection and insulation performance. During the equipment shutdown and cooling phase, the gas temperature inside the shell drops and its volume shrinks, forming negative pressure. External moisture and conductive dust are easily drawn into the shell by the negative pressure, causing a decrease in internal insulation performance and even causing faults such as surface flashover, switch malfunction or failure to operate. In severe cases, it can lead to power outages and safety accidents. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that the protection capability of the existing power distribution cabinet cannot be adaptively adjusted according to the operating conditions, and to propose a mine high-voltage safety power distribution cabinet and its usage method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A mine high-voltage safety distribution cabinet and its usage method include a metal cabinet body, a metal cabinet door, and a high-voltage switch live part installed inside the metal cabinet body; the interior of the metal cabinet body is divided into an independent equipment chamber and an insulating chamber by an insulating partition, and the high-voltage switch live part is installed inside the insulating chamber.

[0008] A metal door frame is provided between the metal cabinet body and the metal cabinet door. An annular sealing airbag is embedded inside the metal door frame. The sealing airbag is connected to an air pump installed outside the metal cabinet body through an air pipe. An annular mounting groove is opened on the metal door frame facing the metal cabinet door. After the sealing airbag is inflated, it can radially protrude from the annular mounting groove into the door gap to form the first radial seal of the metal shell.

[0009] The inner side of the metal cabinet door is fixed with several guide slide rods, and a sealing inner plate is slidably fitted on the guide slide rods through a linear sliding bearing; the inner side of the metal cabinet door is also provided with several air chambers, and a piston is slidably installed in each air chamber. A piston sealing ring is embedded on the outer periphery of the piston, which divides the air chamber into an inner and outer independent sealing chamber and an outer air chamber. The piston is fixedly connected to the sealing inner plate through a connecting rod.

[0010] An annular elastic sealing gasket is fixed to the side of the inner sealing plate facing the metal cabinet door. The elastic sealing gasket is axially aligned with the inner end face of the metal cabinet door, forming a second axial end face seal on the metal shell.

[0011] Preferably, an elastic telescopic rod is provided inside the atmospheric cavity via a fixed plate, one end of the elastic telescopic rod abutting against the piston end face, and the connecting rod is provided at the other end of the piston.

[0012] Preferably, a limit ring is provided at the end of the guide slide rod facing into the cabinet, and lip seals are embedded at both ends of the linear sliding bearing, with the lips fitting against the surface of the guide slide rod.

[0013] Preferably, a pressure sensor and a temperature sensor are fixedly installed on the top and side walls of the equipment chamber inside the metal cabinet, respectively, and their signal output terminals are led out of the metal cabinet through explosion-proof terminals.

[0014] Preferably, guide rails are vertically fixed on both sides of the inner wall of the insulating chamber, and sliders are fixed on both sides of the high-voltage switch live body. The sliders are embedded in the guide rails to form a sliding fit, and a high-voltage quick-connect terminal is also provided in the insulating chamber.

[0015] Preferably, the bottom of the insulating chamber is provided with a wire hole, a sealing bushing is embedded in the wire hole, and the high-voltage fast terminal is inserted into the sealing bushing and locked with a nut.

[0016] Preferably, an insulating sealing gasket is provided on the side of the sealing inner plate facing the metal door frame, and a sealing liner is also provided on the sealing inner plate, with the sealing liner covering the outer wall of the sealing inner plate.

[0017] Preferably, the side end of the metal door frame is provided with a limiting component for locking the metal cabinet door. The limiting component includes a limiting box and a mounting frame, and the limiting box and the mounting frame are respectively fixed to the side end of the metal door frame and the metal cabinet door. The mounting frame is provided with a connector that can be inserted into the limiting box. The connector has a limiting hole, and the connector is limited by positioning posts on both sides inside the limiting box being inserted into the limiting hole.

[0018] Preferably, the limiting box has two symmetrically arranged sliding grooves, and a sliding rod is slidably arranged in each of the two sliding grooves. The two sliding rods are fixed at both ends by a mounting plate and a positioning post, respectively. The limiting box is also provided with a bidirectional lead screw, and the bottom ends of the two sliding rods are respectively sleeved on both ends of the bidirectional lead screw by a drive rod.

[0019] A method for operating a high-voltage safety distribution cabinet for mining includes the following steps:

[0020] Step S1: Close the cabinet door and insert the connector on the mounting frame into the opening of the limit box until the bottom of the connector abuts against the support base to complete the positioning. Rotate the rotating part to drive the bidirectional screw to rotate, which will drive the left and right positioning pins to be inserted into the limit holes simultaneously to complete the mechanical locking of the cabinet door.

[0021] Start the air pump to inflate the sealing airbag. Stop inflating when the airbag pressure reaches the set value. After the sealing airbag expands, it will radially protrude from the annular mounting groove into the door gap, filling the entire door gap and forming the first radial seal, directly blocking the main passage of gas leakage.

[0022] At this time, the air pressure inside and outside the cabinet is in equilibrium. The elastic telescopic rod keeps the piston and the sealing inner plate in the initial position. The elastic sealing gasket is slightly in contact with the inner end face of the cabinet door to form a second basic axial seal. The insulating sealing gasket and the sealing liner provide auxiliary sealing and insulation barrier at the same time. The two seals are arranged in series, one outside and one inside, to lengthen the gas leakage path and form a basic protective barrier.

[0023] Step S2: After the distribution cabinet is put into operation, the internal circuit breakers, busbars and other heat-generating components continue to dissipate heat, causing the gas inside the cabinet to expand due to heat and form a positive pressure relative to the outside. The positive pressure gas acts directly on the surface of the sealing inner plate facing the inside of the cabinet, generating an axial thrust in the direction of the cabinet door, pushing the sealing inner plate to slide along the guide slide rod towards the cabinet door.

[0024] During the sliding process, the inner sealing plate further compresses the elastic sealing gasket facing the cabinet door, increasing the compression of the elastic sealing gasket and raising the sealing specific pressure. At the same time, the outer edge of the elastic sealing gasket is squeezed and deformed, and part of it extends and embeds into the gap between the cabinet door and the door frame, further filling the gap and blocking the leakage path, forming a second seal with positive pressure enhancement.

[0025] The greater the positive pressure inside the cabinet, the stronger the thrust of the sealing inner plate, and the greater the compression and embedding depth of the elastic sealing gasket into the door gap. The sealing performance adaptively enhances as the equipment load increases, offsetting the seal attenuation caused by the positive pressure pushing the cabinet door outward, achieving a self-reinforcing effect of "the higher the pressure, the tighter the seal." During this process, the piston slides outward synchronously with the sealing inner plate, compressing the elastic telescopic rod to store reset potential energy.

[0026] Step S3: After the distribution cabinet stops operating, the internal heating elements gradually cool down, the gas temperature inside the cabinet drops and the volume shrinks, forming a negative pressure relative to the outside. At this time, the external atmospheric pressure in the atmospheric cavity is greater than the gas pressure inside the cabinet. The pressure difference pushes the piston to slide axially inward towards the cabinet. Through the connecting rod, it drives the sealing inner plate to move towards the door frame, so that the insulating sealing gasket on the side of the sealing inner plate facing the door frame is tightly pressed against the inner end face of the door frame, forming a second seal with enhanced negative pressure.

[0027] The deeper the negative pressure, the greater the pressure difference on both sides of the piston, the stronger the clamping force of the sealing inner plate, and the better the sealing performance as the cooling process progresses. This effectively prevents external moisture and conductive dust from being drawn into the cabinet by the negative pressure, thus avoiding weak sealing windows during the shutdown cooling phase.

[0028] As the temperature inside and outside the cabinet gradually equalizes and the pressure difference disappears, the elastic telescopic rod releases the stored potential energy, pushing the piston to slide outward and reset, causing the inner sealing plate to return to its initial position. The elastic sealing gasket returns to a light pressure state, reducing long-term compression fatigue of the rubber seal and extending its service life.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] 1. When the power distribution cabinet generates positive pressure during operation, the positive pressure gas directly drives the inner sealing plate to slide along the guide slide rod towards the cabinet door, simultaneously increasing the compression and sealing pressure of the elastic sealing gasket. Furthermore, the outer edge of the sealing gasket is deformed by compression and can embed itself into the door gap to further block the leakage path. The higher the positive pressure inside the cabinet, the greater the compression and embedding depth of the sealing gasket. The sealing performance is adaptively enhanced as the equipment load increases, offsetting the problem of sealing force attenuation caused by the positive pressure pushing the cabinet door outward.

[0031] 2. When the distribution cabinet of the present invention is shut down and cooling down, a negative pressure is formed inside the cabinet. The external atmospheric pressure pushes the inner sealing plate towards the door frame through the piston structure, so that the insulating sealing gasket is tightly pressed against the inner end face of the door frame. The deeper the negative pressure, the greater the pressure difference on both sides of the piston, and the stronger the sealing and pressing force. It can effectively prevent external moisture and conductive dust from being sucked into the cabinet by the negative pressure, avoid the risk of the insulation performance deterioration during the shutdown cooling stage of the traditional structure, and fill the gap in sealing protection under shutdown conditions.

[0032] 3. This invention uses an inflatable annular sealing airbag as the first radial seal, and works with the elastic sealing gasket on the inner sealing plate to form the second axial end face seal. The two seals are arranged in series, one outer and one inner, which effectively lengthens the gas leakage path and directly blocks the main leakage path of the door gap. The insulating sealing gasket and sealing liner provide auxiliary sealing and insulation barrier. Compared with the traditional static sealing scheme of single rubber sealing strip, the basic sealing reliability and protection level are greatly improved, which can better adapt to the harsh environment of high dust and high tide in mines. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a mine high-voltage safety distribution cabinet and its usage method proposed in this invention;

[0034] Figure 2 This is a schematic diagram of the internal structure of the cabinet;

[0035] Figure 3 For the present invention Figure 2 Enlarged view of a portion of point A in the middle;

[0036] Figure 4 A schematic diagram of the assembly structure of the door frame and the sealing airbag;

[0037] Figure 5 A schematic diagram of the sensor installation structure inside the equipment cavity;

[0038] Figure 6 This is a schematic diagram of the assembly structure of charged parts inside an insulating cavity;

[0039] Figure 7 A three-dimensional structural diagram of the inner sealing panel on the inside of the cabinet door;

[0040] Figure 8 Exploded view of the cabinet door and sealing inner panel assembly;

[0041] Figure 9 for Figure 8 Enlarged view of a portion of point B in the middle;

[0042] Figure 10 A schematic diagram of the assembly of the sealed inner panel and cabinet door;

[0043] Figure 11A schematic diagram showing the arrangement of the guide slide rod and air chamber holes on the inner side of the cabinet door;

[0044] Figure 12 This is a cross-sectional view of the internal lead screw locking mechanism of the limiting component.

[0045] In the diagram: 1. Cabinet body; 2. Cabinet door; 201. Guide slide rod; 202. Sealing inner panel; 203. Insulating sealing gasket; 204. Sealing liner; 205. Elastic sealing gasket; 3. Door frame; 301. Annular mounting groove; 302. Sealing airbag; 303. Inflation pump; 4. Limiting box; 401. Mounting frame; 402. Connector; 403. Limiting hole; 404. Support base; 405. Sliding groove; 406. Sliding rod; 407. Mounting plate; 408. Positioning. 409. Column; 410. Drive rod; 411. Double-acting lead screw; 412. Rotating part; 5. Piston; 501. Atmospheric cavity; 502. Sealed cavity; 503. Piston seal ring; 504. Connecting rod; 505. Elastic telescopic rod; 506. Fixing plate; 6. Insulating partition; 601. Equipment chamber; 602. Insulating chamber; 603. Mounting beam; 604. Temperature sensor; 605. Pressure sensor; 606. High-voltage quick-connect terminal; 607. Live part; 7. Handle. Detailed Implementation

[0046] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0047] Reference Figures 1-12 A mine high-voltage safety distribution cabinet includes a cabinet body 1, a cabinet door 2, a door frame 3, a sealing inner plate 202, a sealing airbag 302, a piston 5, and a limiting component. The cabinet door 2 is hinged to the front side of the cabinet body 1. The door frame 3 is fixedly installed at the opening on the front side of the cabinet body 1. The sealing inner plate 202 is installed inside the cabinet door 2 and can slide back and forth along the guide slide rod 201. The sealing airbag 302 is embedded in the annular mounting groove 301 of the door frame 3. The piston 5 is slidably installed in the air cavity inside the cabinet door 2 and is fixedly connected to the sealing inner plate 202 through a connecting rod 504. The limiting component is installed on the opening and closing side of the door frame 3 and the cabinet door 2.

[0048] Reference Figure 1 and Figure 2Cabinet 1 is used to house and protect internal electrical components and is fixedly connected to the installation foundation of the underground power distribution system. Cabinet door 2 is used to close the front opening of cabinet 1 and adaptively adjusts the sealing pressure ratio under positive and negative pressure conditions through the sealing inner plate 202. Door frame 3 serves as a transitional connection component between cabinet 1 and cabinet door 2, providing an installation foundation for sealing airbag 302. Sealing inner plate 202 is used to support multiple sealing structures and slides back and forth along guide rod 201 under air pressure drive to achieve positive pressure enhanced sealing and negative pressure enhanced sealing. Sealing airbag 302 serves as the first radial seal and is used to fill the door gap after inflation. Piston 5 is used to sense the air pressure difference inside and outside the cabinet and convert the air pressure difference into a mechanical driving force to drive the sealing inner plate 202 to slide. Limiting component is used for mechanical locking after cabinet door 2 is closed to prevent positive pressure inside the cabinet from pushing cabinet door 2 open.

[0049] Reference Figures 1 to 4 The cabinet 1 is a rectangular hollow box structure, welded from mining flame-retardant steel plate. The front side has an opening for the cabinet door 2 to be hinged and closed. The interior of the cabinet 1 is horizontally welded and fixed with a mounting beam 603, which is a C-shaped steel component arranged horizontally along the left and right directions of the cabinet 1. It is used to support and fix the insulating partition 6. The bottom of the cabinet 1 has a wire hole with a sealing bushing, which is used to pass through the high-voltage fast terminal 606. The side wall of the cabinet 1 is equipped with explosion-proof terminals for leading the signal cables of the sensors inside the cabinet out of the cabinet. The top and bottom outer sides of the cabinet 1 are equipped with mounting ears with bolt holes for bolt fixing to the foundation channel steel or suspension bracket of the underground power distribution chamber to support and fix the entire power distribution cabinet.

[0050] Reference Figure 1 , Figure 2 and Figure 11 Cabinet door 2 is a rectangular flat panel door. One side of it is hinged to the front opening edge of cabinet 1 by a heavy-duty hinge, and the other side is the opening and closing side, which is locked to the door frame 3 by a limiting member. A handle 7 is fixedly installed on the outside of cabinet door 2 to facilitate the operator to open and close the cabinet door. Several guide slide rods 201 (four in this embodiment, respectively arranged at the four corners of cabinet door 2) are vertically welded and fixed on the inner end face of cabinet door 2. The guide slide rods 201 are cylindrical steel rods with their axes perpendicular to the plane of cabinet door 2 and extending horizontally inward. Each guide slide rod 201 has an annular groove at its end, and a limiting retaining ring is installed in the groove to limit the maximum sliding stroke of the sealing inner plate 202 inward.

[0051] The sealing inner plate 202 is a rectangular flat plate component, formed by stamping cold-rolled steel plate. Its external dimensions match the inner opening area of ​​the cabinet door 2. The four corners of the sealing inner plate 202 are respectively provided with guide through holes. A linear sliding bearing is press-fitted into each guide through hole. The guide slide rod 201 passes through the inner hole of the linear sliding bearing to form a sliding fit, so that the sealing inner plate 202 can only reciprocate along the axial direction of the guide slide rod 201 (i.e., the direction perpendicular to the plane of the cabinet door 2). The two ends of the linear sliding bearing are fitted with lip seals, and the lips fit against the surface of the guide slide rod 201 to ensure the airtightness of the sliding fit position.

[0052] An annular elastic sealing gasket 205 is fixed on the side end face of the inner sealing plate 202 facing the cabinet door 2. The elastic sealing gasket 205 is arranged circumferentially along the edge of the inner sealing plate 202 to form a rectangular closed loop. It is made of mining flame-retardant nitrile rubber. The elastic sealing gasket 205 is axially aligned with the inner end face of the cabinet door 2 and maintains slight contact under normal conditions. When the inner sealing plate 202 slides toward the cabinet door 2, the elastic sealing gasket 205 is axially compressed. After its outer edge is squeezed and deformed, it can be partially embedded in the gap between the cabinet door 2 and the door frame 3.

[0053] An insulating sealing gasket 203 is fixed on the end face of the inner sealing plate 202 facing the door frame 3. The insulating sealing gasket 203 is arranged in a closed loop along the circumference and is made of insulating and flame-retardant rubber material. It has the dual functions of sealing and electrical insulation. A sealing liner 204 is also covered and fixed on the outer peripheral wall of the inner sealing plate 202. The sealing liner 204 is made of wear-resistant and flame-retardant rubber material. Its outer edge is in a small gap fit with the inner wall of the door frame 3. It is used to seal the annular gap between its outer wall and the inner wall of the door frame 3 when the inner sealing plate 202 slides axially, and at the same time plays a guiding and buffering role.

[0054] Reference Figure 2 , Figure 3 and Figure 4 The door frame 3 is a ring-shaped frame component, which is welded to the opening edge on the front side of the cabinet 1. A continuous ring-shaped mounting groove 301 is opened on the side wall of the door frame 3 facing the cabinet door 2. The cross-section of the ring-shaped mounting groove 301 is circular or square, and it is arranged in a closed loop along the upper beam, lower beam and two side columns of the door frame 3.

[0055] The sealing airbag 302 is an annular hollow bladder made of flame-retardant and oil-resistant neoprene rubber. It is fully embedded inside the annular mounting groove 301. The sealing airbag 302 is normally in a contracted state and is completely housed in the annular mounting groove 301, without protruding from the side wall surface of the door frame 3. The air inlet of the sealing airbag 302 is connected to a high-pressure resistant rubber air pipe. The air pipe is laid along the wiring groove inside the door frame 3, passes through the explosion-proof wiring hole on the side wall of the cabinet 1, and connects to the air outlet of the air pump 303, which is fixedly installed outside the cabinet 1. The air pump 303 is a miniature electric air pump, and its air inlet is equipped with a filter device to prevent underground dust from being sucked in.

[0056] When the air pump 303 starts and fills the sealing airbag 302 with compressed air, the sealing airbag 302 expands under the action of air pressure and protrudes radially from the opening of the annular mounting groove 301, filling the entire door gap between the cabinet door 2 and the door frame 3, forming the first radial sealing barrier.

[0057] Reference Figure 8 , Figure 9 and Figure 11 The inner side of cabinet door 2 is provided with several air chambers (four in this embodiment, respectively arranged at the midpoints of the upper, lower, left, and right sides of the inner side of cabinet door 2). The air chambers are cylindrical hollow cavities, and their axes are arranged parallel to the guide slide rod 201. The air chambers can be integrally cast with cabinet door 2, or they can be fixed to the inner wall of cabinet door 2 by cylinder liner.

[0058] A piston 5 is coaxially slidably disposed inside each air chamber. The piston 5 is a cylindrical metal part with an annular sealing groove on its outer peripheral wall. A piston sealing ring 503 is embedded in the groove. The piston sealing ring 503 is interference-fitted with the inner wall of the air chamber, dividing the internal space of the air chamber into an unconnected large air chamber 501 and a sealed chamber 502.

[0059] The atmospheric cavity 501 is located at the outer end of the air cavity (i.e., the end closest to the outer wall of the cabinet door 2). A vent is provided on the cavity wall, penetrating the outer wall of the cabinet door 2, so that the interior of the atmospheric cavity 501 is always connected to the outside atmosphere. An elastic telescopic rod 505 is fixedly installed on the inner wall of the outer end of the atmospheric cavity 501 by a fixing plate 506. The elastic telescopic rod 505 consists of a sleeve, an inner rod and a built-in compression spring. The end of the inner rod abuts against the outer end face of the piston 5, which is used to push the piston 5 to reset after the pressure difference disappears. The sealing cavity 502 is located at the inner end of the air cavity (i.e., the end closest to the inside of the cabinet), and is indirectly connected to the interior space of the cabinet 1 through the gap between the sealing inner plate 202 and the cabinet door 2.

[0060] The inner end face of piston 5 is fixedly connected to the inner sealing plate 202 via connecting rod 504. Specifically, one end of connecting rod 504 is threaded to the inner end face of piston 5, and the other end passes through the inner end cover of the air chamber and is bolted to the end face of the inner sealing plate 202 facing the cabinet door 2. A rod sealing ring is provided at the mating point between the inner end cover of the air chamber and the connecting rod 504 to ensure the airtightness of the sealing cavity 502 when the connecting rod 504 slides back and forth.

[0061] When the air pressure inside the cabinet is greater than the external air pressure (positive pressure condition), the positive pressure gas acts on the entire surface of the sealing inner plate 202 facing the inside of the cabinet, generating an axial thrust in the direction of the cabinet door 2. This pushes the sealing inner plate 202 to slide along the guide slide rod 201 towards the cabinet door 2. At the same time, it drives the piston 5 to slide towards the atmospheric cavity 501 through the connecting rod 504. When the air pressure inside the cabinet is less than the external air pressure (negative pressure condition), the external atmospheric pressure in the atmospheric cavity 501 pushes the piston 5 to slide towards the inside of the cabinet. This drives the sealing inner plate 202 to slide towards the door frame 3 through the connecting rod 504.

[0062] Reference Figure 12 Limiting components are provided on the opening and closing sides of the door frame 3 and the cabinet door 2 for mechanical locking after the cabinet door 2 is closed. The limiting components include a limiting box 4 and a mounting frame 401. The limiting box 4 is fixedly installed on the opening and closing end face of the door frame 3, and the mounting frame 401 is fixedly installed on the opening and closing end face of the cabinet door 2. The two are aligned horizontally after the cabinet door 2 is closed.

[0063] A connector 402 is vertically fixed on one end face of the mounting frame 401 facing the limiting box 4. The connector 402 is a rectangular block component with a limiting hole 403. The limiting hole 403 is a circular through hole with a chamfered guide treatment at the opening.

[0064] The limiting box 4 is a hollow metal box with a rectangular opening on the side facing the mounting frame 401 that is compatible with the connector 402 for insertion. A support base 404 is fixed at the bottom inside the limiting box 4. The top surface of the support base 404 is a flat support surface. When the connector 402 is fully inserted into the limiting box 4, the bottom end face of the connector 402 abuts against the top surface of the support base 404 to achieve positioning of the insertion depth.

[0065] Two horizontally extending sliding grooves 405 are symmetrically opened on the two side walls inside the limiting box 4. A sliding rod 406 is slidably embedded in each sliding groove 405. The sliding rod 406 can move horizontally back and forth along the sliding groove 405. Mounting plates 407 are fixed on the opposite side end faces of the two sliding rods 406 respectively. A positioning post 408 is vertically fixed on the opposite end face of each of the two mounting plates 407. The two positioning posts 408 are arranged coaxially, and the ends of the posts are chamfered to facilitate insertion into the limiting hole 403.

[0066] A bidirectional lead screw 410 is horizontally installed at the lower part of the inner part of the limit box 4. The two ends of the bidirectional lead screw 410 are respectively machined with positive thread sections and negative thread sections with opposite directions of rotation. The upper ends of the two drive rods 409 are respectively fixedly connected to the bottom ends of the corresponding sliding rods 406, and the lower ends are respectively fitted onto the threaded sections at both ends of the bidirectional lead screw 410 through threaded holes to form a lead screw nut transmission pair. A rotating part 411 is provided on the outer wall of the limit box 4. The rotating part 411 is an internal hexagonal knob, and its inner end is coaxially fixedly connected to one end of the bidirectional lead screw 410. The operator can drive the bidirectional lead screw 410 to rotate by rotating the rotating part 411 with a special wrench, so that the two positioning pins 408 are simultaneously inserted into or withdrawn from the limit hole 403 to complete the locking or unlocking of the cabinet door 2.

[0067] In some implementations, the limiting component can also use an electromagnetic lock to replace the mechanical screw locking structure. That is, the extension and retraction of the positioning column 408 are controlled by the on and off of the electromagnet, so as to realize the automatic locking and unlocking of the cabinet door 2, which is convenient for remote control.

[0068] Reference Figure 1 , Figure 2 , Figure 5 and Figure 6 The cabinet 1 is equipped with an insulating partition 6, which is a rectangular flat plate made of epoxy resin board. The insulating partition 6 is fixedly installed on the mounting beam 603, dividing the internal cavity of the cabinet 1 into a front equipment chamber 601 and a rear insulating chamber 602. The equipment chamber 601 is used to house control elements, sensing components and auxiliary circuits, while the insulating chamber 602 is a closed independent space used to install high-voltage live parts.

[0069] The insulating chamber 602 is formed by the insulating partition 6, the rear wall, left and right side walls and the bottom plate of the cabinet 1. The inner walls on the left and right sides of the insulating chamber 602 are vertically fixed with guide rails. The guide rails are C-shaped groove structures and are made of reinforced nylon insulation material. The live body 607 has sliders fixed on both sides. The sliders are embedded in the C-shaped grooves of the guide rails to form a sliding fit, so that the live body 607 can be pulled up and down along the vertical direction of the guide rails, which is convenient for inspection and maintenance.

[0070] The bottom of the insulating chamber 602 is provided with a wire-passing hole, and a sealing bushing is embedded in the wire-passing hole. The high-voltage quick-connect terminal 606 passes through the sealing bushing and is locked by nuts at the upper and lower ends. When locked, the sealing bushing is squeezed and deformed to fill the annular gap of the wire-passing hole, thereby achieving an airtight seal at the wire-passing position.

[0071] A pressure sensor 605 is fixedly installed on the top wall of the equipment chamber 601, and a temperature sensor 604 is fixedly installed on the side wall. The pressure sensor 605 is a piezoresistive transmitter used to detect the air pressure inside the cabinet in real time, and the temperature sensor 604 is a platinum resistance thermometer used to detect the temperature inside the cabinet in real time. The signal output cables of the two are led out of the cabinet 1 through the explosion-proof terminal block on the side wall of the cabinet 1 and connected to the underground monitoring system.

[0072] It should be noted that the specific models, ranges, and control parameters of the aforementioned electrical components, such as the air pump 303, pressure sensor 605, and temperature sensor 604, need to be selected conventionally based on the voltage level and protection requirements of the mine's power supply system. The specific selection and calculation methods utilize existing technology in this field and will not be elaborated upon here.

[0073] The functional principle of this invention can be explained through the following operational methods:

[0074] Close the cabinet door 2, so that the connector 402 on the mounting frame 401 is inserted into the opening of the limit box 4 until the bottom end of the connector 402 abuts against the support base 404 to complete the positioning. Rotate the rotating part 411 to drive the bidirectional lead screw 410 to rotate, which drives the left and right positioning pins 408 to be inserted into the limit hole 403 simultaneously, thus completing the mechanical locking of the cabinet door 2.

[0075] Start the air pump 303 to inflate the sealing airbag 302. When the airbag pressure reaches the set value, stop inflating. After the sealing airbag 302 expands, it radially protrudes from the annular mounting groove 301 into the door gap, filling the entire door gap and forming the first radial seal, directly blocking the main passage of gas leakage.

[0076] At this time, the air pressure inside and outside the cabinet is in a balanced state. The elastic telescopic rod 505 keeps the piston 5 and the sealing inner plate 202 in the initial position. The elastic sealing gasket 205 is slightly in contact with the inner end face of the cabinet door 2 to form a second basic axial seal. The insulating sealing gasket 203 and the sealing liner 204 provide auxiliary sealing and insulation barrier at the same time. The two seals are arranged in series, one outside and one inside, to lengthen the gas leakage path and form a basic protective barrier.

[0077] After the distribution cabinet is put into operation, the internal circuit breakers, busbars and other heat-generating components continue to dissipate heat, causing the gas inside the cabinet to expand due to heat and form a positive pressure relative to the outside. The positive pressure gas acts directly on the surface of the sealing inner plate 202 facing the inside of the cabinet, generating an axial thrust in the direction of the cabinet door 2, which pushes the sealing inner plate 202 to slide along the guide slide rod 201 towards the cabinet door 2.

[0078] During the sliding process, the inner sealing plate 202 further compresses the elastic sealing gasket 205 facing the cabinet door 2, increasing the compression of the elastic sealing gasket 205 and raising the sealing specific pressure. At the same time, the outer edge of the elastic sealing gasket 205 is squeezed and deformed, and part of it extends and embeds into the gap between the cabinet door 2 and the door frame 3, further filling the gap and blocking the leakage path, forming a second seal with positive pressure enhancement.

[0079] The greater the positive pressure inside the cabinet, the stronger the thrust of the sealing inner plate 202, and the greater the compression and embedding depth of the elastic sealing gasket 205 into the door gap. The sealing performance adaptively enhances as the equipment load increases, offsetting the sealing attenuation caused by the positive pressure pushing the cabinet door 2 outward, achieving a self-reinforcing effect of "the higher the pressure, the tighter the seal." During this process, the piston 5 slides outward synchronously with the sealing inner plate 202, compressing the elastic telescopic rod 505 to store reset potential energy.

[0080] After the distribution cabinet stops operating, the internal heating elements gradually cool down, the gas temperature inside the cabinet drops and the volume shrinks, forming a negative pressure relative to the outside. At this time, the external atmospheric pressure in the atmospheric cavity 501 is greater than the gas pressure inside the cabinet. The pressure difference pushes the piston 5 to slide axially inward towards the inside of the cabinet. Through the connecting rod 504, it drives the sealing inner plate 202 to move towards the door frame 3, so that the insulating sealing gasket 203 on the side of the sealing inner plate 202 facing the door frame 3 is tightly pressed against the inner end face of the door frame 3, forming a second seal with enhanced negative pressure.

[0081] The deeper the negative pressure, the greater the pressure difference on both sides of the piston 5, the stronger the clamping force of the sealing inner plate 202, and the sealing performance adapts and improves with the cooling process. It can effectively prevent external moisture and conductive dust from being sucked into the cabinet 1 by the negative pressure, and avoid the occurrence of weak sealing windows during the shutdown cooling phase.

[0082] When the temperature inside and outside the cabinet gradually equalizes and the pressure difference disappears, the elastic telescopic rod 505 releases the stored potential energy, pushes the piston 5 to slide outward and reset, and drives the inner sealing plate 202 back to the initial position. The elastic sealing gasket 205 returns to a light pressure state, reducing the long-term compression fatigue of the rubber seal and extending its service life.

[0083] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A mine high-voltage safety distribution cabinet, characterized in that, It includes a metal cabinet (1), a metal cabinet door (2), and a high-voltage switch live part (607) installed inside the metal cabinet (1); the interior of the metal cabinet (1) is divided into an independent equipment chamber (601) and an insulating chamber (602) by an insulating partition (6), and the high-voltage switch live part (607) is installed inside the insulating chamber (602); A metal door frame (3) is provided between the metal cabinet (1) and the metal cabinet door (2). An annular sealing airbag (302) is embedded inside the metal door frame (3). The sealing airbag (302) is connected to an air pump (303) provided outside the metal cabinet (1) through an air pipe. An annular mounting groove (301) is provided on the metal door frame (3) facing the metal cabinet door (2). After the sealing airbag (302) is inflated, it can radially protrude from the annular mounting groove (301) into the door gap to form the first radial seal of the metal shell. The metal cabinet door (2) has several guide slide rods (201) fixed on its inner side. A sealing inner plate (202) is slidably mounted on the guide slide rods (201) through a linear sliding bearing. The metal cabinet door (2) also has several air chambers on its inner side. A piston (5) is slidably mounted in each air chamber. A piston sealing ring (503) is embedded on the outer periphery of the piston (5), which divides the air chamber into an inner and outer independent sealing chamber (502) and an outer air chamber (501). The piston (5) is fixedly connected to the sealing inner plate (202) through a connecting rod (504). The inner sealing plate (202) is fixed with an annular elastic sealing gasket (205) on the side facing the metal cabinet door (2). The elastic sealing gasket (205) is axially aligned with the inner end face of the metal cabinet door (2), forming the second axial end face seal of the metal shell.

2. The mine high-voltage safety distribution cabinet according to claim 1, characterized in that, An elastic telescopic rod (505) is provided inside the atmospheric cavity (501) via a fixing plate (506). One end of the elastic telescopic rod (505) abuts against the end face of the piston (5), and the connecting rod (504) is provided at the other end of the piston (5).

3. A mine high-voltage safety distribution cabinet according to claim 2, characterized in that, The guide slide rod (201) is provided with a limit ring at the end facing the cabinet, and the linear sliding bearing is fitted with lip seals at both ends, with the lips fitting the surface of the guide slide rod (201).

4. A mine high-voltage safety distribution cabinet according to claim 3, characterized in that, A pressure sensor (605) and a temperature sensor (604) are fixedly installed on the top and side walls of the equipment chamber (601) inside the metal cabinet (1), respectively, and the signal output terminals of the two sensors are led out of the metal cabinet (1) through explosion-proof terminals.

5. A mine high-voltage safety distribution cabinet according to claim 4, characterized in that, The insulating chamber (602) has guide rails fixed vertically on both sides of its inner walls. The high-voltage switch live body (607) has sliders fixed on both sides. The sliders are embedded in the guide rails to form a sliding fit. The insulating chamber (602) is also equipped with a high-voltage quick-connect terminal (606).

6. A mine high-voltage safety distribution cabinet according to claim 5, characterized in that, The bottom of the insulating chamber (602) is provided with a wire hole, and a sealing bushing is embedded in the wire hole. The high-voltage quick-connect terminal (606) is inserted into the sealing bushing and locked with a nut.

7. A mine high-voltage safety distribution cabinet according to claim 6, characterized in that, An insulating sealing gasket (203) is provided on the side of the sealing inner plate (202) facing the metal door frame (3), and a sealing liner (204) is also provided on the sealing inner plate (202), and the sealing liner (204) covers the outer wall of the sealing inner plate (202).

8. A mine high-voltage safety distribution cabinet according to claim 7, characterized in that, The metal door frame (3) is provided with a limiting component for locking the metal cabinet door (2) on its side. The limiting component includes a limiting box (4) and a mounting frame (401). The limiting box (4) and the mounting frame (401) are respectively fixed to the side of the metal door frame (3) and the metal cabinet door (2). The mounting frame (401) is provided with a connector (402) that can be inserted into the limiting box (4). The connector (402) has a limiting hole (403). The connector (402) is limited by the positioning posts (408) on both sides of the limiting box (4) being inserted into the limiting hole (403).

9. A mine high-voltage safety distribution cabinet according to claim 8, characterized in that, The limiting box (4) has two symmetrically arranged sliding grooves (405), and sliding rods (406) are slidably arranged in the two sliding grooves (405). The two ends of the two sliding rods (406) are fixed by mounting plates (407) and positioning posts (408) respectively. The limiting box (4) is also provided with a bidirectional lead screw (410). The bottom ends of the two sliding rods (406) are respectively sleeved on the two ends of the bidirectional lead screw (410) by drive rods (409).

10. A method for using a mine high-voltage safety distribution cabinet as described in claim 9, characterized in that, The following steps are included: Step S1: Close the cabinet door (2), insert the connector (402) on the mounting frame (401) into the opening of the limit box (4) until the bottom end of the connector (402) abuts against the support base (404) to complete the positioning. Rotate the rotating part (411) to drive the bidirectional screw (410) to rotate, and drive the left and right positioning columns (408) to be inserted into the limit hole (403) simultaneously to complete the mechanical locking of the cabinet door (2). Start the air pump (303) to inflate the sealing airbag (302). When the airbag pressure reaches the set value, stop inflating. After the sealing airbag (302) expands, it radially protrudes from the annular mounting groove (301) into the door gap, filling the entire door gap and forming the first radial seal, directly blocking the main passage of gas leakage. At this time, the air pressure inside and outside the cabinet is in a balanced state. The elastic telescopic rod (505) keeps the piston (5) and the sealing inner plate (202) in the initial position. The elastic sealing gasket (205) is slightly in contact with the inner end face of the cabinet door (2) to form a second basic axial seal. The insulating sealing gasket (203) and the sealing liner (204) provide auxiliary sealing and insulation barrier at the same time. The two seals are arranged in series, one outside and one inside, to lengthen the gas leakage path and form a basic protective barrier. Step S2: After the distribution cabinet is put into operation, the internal circuit breakers, busbars and other heat-generating components continue to dissipate heat, causing the gas inside the cabinet to expand due to heat and form a positive pressure relative to the outside. The positive pressure gas directly acts on the entire surface of the sealing inner plate (202) facing the inside of the cabinet, generating an axial thrust in the direction of the cabinet door (2), pushing the sealing inner plate (202) to slide along the guide slide rod (201) towards the cabinet door (2); During the sliding process, the inner sealing plate (202) further compresses the elastic sealing gasket (205) facing the cabinet door (2), increasing the compression of the elastic sealing gasket (205) and raising the sealing pressure. At the same time, the outer edge of the elastic sealing gasket (205) is squeezed and deformed, and part of it extends and embeds into the gap between the cabinet door (2) and the door frame (3), further filling the gap and blocking the leakage path, forming a second seal with positive pressure enhancement. The greater the positive pressure inside the cabinet, the stronger the thrust of the sealing inner plate (202), and the greater the compression of the elastic sealing gasket (205) and the greater the depth of embedding in the door gap. The sealing performance is adaptively enhanced as the equipment load increases, which offsets the sealing attenuation caused by the positive pressure pushing the cabinet door (2) outward, and achieves the self-reinforcing effect of "the higher the pressure, the tighter the seal". During this process, the piston (5) slides outward synchronously with the sealing inner plate (202), compressing the elastic telescopic rod (505) to store the reset potential energy; Step S3: After the power distribution cabinet stops operating, the internal heating elements gradually cool down, the gas temperature inside the cabinet drops and the volume shrinks, forming a negative pressure relative to the outside. At this time, the external atmospheric pressure in the atmospheric cavity (501) is greater than the gas pressure inside the cabinet. The pressure difference pushes the piston (5) to slide axially inward towards the cabinet. Through the connecting rod (504), it drives the sealing inner plate (202) to move towards the door frame (3), so that the insulating sealing gasket (203) of the sealing inner plate (202) facing the door frame (3) is tightly pressed against the inner end face of the door frame (3), forming a second seal with enhanced negative pressure. The deeper the negative pressure, the greater the pressure difference on both sides of the piston (5), the stronger the clamping force of the sealing inner plate (202), and the sealing performance adapts to the cooling process. It can effectively block external moisture and conductive dust from being sucked into the cabinet (1) by the negative pressure, and avoid the occurrence of weak sealing windows during the shutdown cooling stage. When the temperature inside and outside the cabinet gradually balances and the pressure difference disappears, the elastic telescopic rod (505) releases the stored potential energy, pushes the piston (5) to slide outward to reset, and drives the inner sealing plate (202) back to the initial position. The elastic sealing gasket (205) returns to a light pressure state, reducing the long-term compression fatigue of the rubber seal and extending its service life.

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