Energy-saving and environment-friendly medium-voltage looped network switch device

Abstract

The present application relates to the technical fields of closed switch device, specifically is energy saving and environment-friendly medium voltage looped network switch equipment, the present application includes looped network cabinet body, the looped network cabinet body inside is provided with air chamber, air chamber inside is provided with variable volume pressure maintaining unit, sudden jump trigger unit and convection dehumidification unit, the present application utilizes bellows pressure difference response, drives piston cylinder to quickly pull out when extreme overload, withdraws its barrier to air inlet, air outlet, forms low resistance straight-through large air duct in dehumidification bin, makes total air volume of fan blade blown out instantaneous surge, inhibits resin moisture mass migration from source by limit forced convection heat dissipation, when load falls back or night temperature drops suddenly, mechanism reverse reset quickly rebuilds closed air duct, utilizes high-efficiency desorption regenerated strong molecular sieve, absorbs free moisture in gas before gas reaches saturation dew point, destroys liquid condensation formation condition, guarantees dielectric insulation safety under low insulation resistance environment-friendly medium.

Description

Technical Field

[0001] This invention relates to the field of enclosed switchgear technology, specifically to energy-saving and environmentally friendly medium-voltage ring network switchgear. Background Technology

[0002] With the rapid development of my country's smart grid industry, especially the upgrading and transformation of high-voltage power supply (such as AC transmission above 750 kV, large-scale power grid security and defense systems, and intelligent dispatching systems) and medium- and low-voltage distribution networks, the safe and reliable operation of power distribution equipment faces higher technical requirements. In urban power supply networks and industrial distribution systems, switchgear with enclosed enclosures or structurally integrated switches and enclosures (such as environmentally friendly gas-insulated ring main units) has been widely used. In recent years, with increasingly stringent global power industry requirements for greenhouse gas emission reduction, environmentally friendly gas-insulated switchgear using high-purity nitrogen, dry air, or environmentally friendly mixed gases as insulating media is gradually replacing traditional sulfur hexafluoride high-voltage equipment.

[0003] However, since the insulating properties of environmentally friendly gases such as nitrogen are generally inferior to those of sulfur hexafluoride, in order to meet insulation distance requirements and achieve miniaturized and compact equipment designs, environmentally friendly gas-insulated cabinets require the extensive use of solid insulating components such as epoxy resin. This is achieved through a gas-solid composite insulation method to optimize the internal electric field. As a core component, the epoxy resin insulating component, during the mixing and cross-linking curing process, inevitably accumulates trace amounts of deeply adsorbed moisture within its matrix due to limitations imposed by the three-dimensional network molding of the polymer and the microscopic characteristics of the solid fillers. Because these insulating components are relatively thick, and excessive high-temperature baking can cause thermal aging or performance degradation of the resin material, it is difficult to completely remove the residual moisture deep within the resin during the conventional vacuum drying process before shipment.

[0004] In the subsequent actual operation of environmentally friendly switchgear, the heat generated by the main circuit causes residual moisture deep within the resin to gradually migrate outward and be released into the insulating gas within the sealed gas chamber. However, when the load decreases at night or the ambient temperature drops sharply, the metal gas chamber shell cools extremely rapidly, causing the internal gas to contract quickly. But the large-volume epoxy resin components, due to their high thermal inertia, experience a significant lag in cooling. This misalignment in the cooling sequence of solid and gas causes the moisture in the gas to reach its saturation dew point instantaneously during the sudden temperature drop, condensing into tiny water droplets on the still-warm surfaces of the insulating components or the cooled metal inner walls. Since nitrogen gas has a much lower insulation tolerance to liquid surface condensation than sulfur hexafluoride, these tiny water droplets can easily trigger severe surface discharge flashover accidents, posing a significant threat to the safe and stable operation of large-scale power grids. Summary of the Invention

[0005] The purpose of this invention is to provide an energy-saving and environmentally friendly medium-voltage ring network switchgear to solve the problems mentioned in the background art.

[0006] The objective of this invention can be achieved through the following technical solutions: An energy-saving and environmentally friendly medium-voltage ring main switchgear, preferably, includes a ring main cabinet body, wherein an air chamber is provided inside the ring main cabinet body, and a variable capacity pressure maintaining unit, a sudden trip triggering unit and a convection dehumidification unit are provided inside the air chamber; The convection dehumidification unit includes a cylindrical dehumidification chamber located at the bottom of the air chamber, a piston cylinder that is slidably disposed inside the dehumidification chamber, and molecular sieves filling the inside of the piston cylinder; The variable capacity pressure holding unit is used to sense the temperature and pressure changes inside the air chamber and generate shape expansion and contraction. The jump trigger unit is connected between the variable capacity pressure holding unit and the piston cylinder. When the variable capacity pressure holding unit expands or contracts to a preset extent, it drives the piston cylinder to move axially along the dehumidification chamber, thereby switching between different operating conditions of the convection dehumidification unit.

[0007] Preferably, one end of the dehumidification chamber extends to the outside of the air chamber and has a dehumidification outlet at the extended end, and the end of the dehumidification chamber located inside the air chamber has an air inlet and is equipped with a convection component. One end of the piston cylinder is symmetrically provided with ventilation ports adapted to the air inlet and the convection assembly, respectively, and the other end of the piston cylinder is provided with a regeneration port adapted to the dehumidification port.

[0008] Preferably, the convection dehumidification unit further includes an arc-shaped heater, which is disposed on the inner wall of one end of the dehumidification chamber extending into the air chamber, and is sleeved on the outer periphery of the piston cylinder.

[0009] Preferably, the variable capacity pressure holding unit includes a guide chamber, a bellows, a T-shaped guide rod, and a return spring; The guide chamber is located at the bottom of the air chamber and is connected to the interior of the air chamber. The bellows is located inside the guide chamber and is sealed and filled with atmospheric pressure air. The T-shaped guide rod is arranged along the axial direction of the guide chamber and is fixed to the end of the bellows. One end of the T-shaped guide rod passes through the guide chamber and is slidably connected to the guide chamber. The return spring is sleeved on the outer periphery of the T-shaped guide rod and is located between the T-shaped guide rod and the guide chamber.

[0010] Preferably, a guide groove is provided on one side of the guide chamber along the axial direction, and the jump trigger unit includes a guide slide rod, a drive rod and a pair of drive rollers; The guide slide rod is fixedly connected to one end of the T-shaped guide rod that protrudes from the guide chamber, and one end of the guide slide rod passes through the guide groove and is fixedly connected to the drive rod. A pair of transmission rollers are set at one end of the drive rod.

[0011] Preferably, the jump trigger unit further includes a transmission gear and a driven rod; The transmission gear is rotatably connected inside the air chamber, and the driven rod is fixedly connected to the shaft end of the transmission gear, with its end positioned between a pair of transmission rollers. A hook is fixedly installed in the middle section of the driven rod. One end of the hook is hooked with a tension spring, and the other end of the tension spring is hooked with the inner wall of the air chamber.

[0012] Preferably, a transmission groove is provided on one side of the dehumidification chamber, a transmission slider is fixedly connected to the middle section of the piston cylinder, one end of the transmission slider passes through the transmission groove and is fixedly connected to a transmission rack, and the transmission rack meshes with a transmission gear.

[0013] Preferably, the convection assembly includes an air outlet and a cylindrical cover. The air outlet and the air inlet are coaxially opposite each other, the cylindrical cover is located at the output end of the air outlet, and a fan blade is rotatably arranged inside the cylindrical cover.

[0014] Preferably, the shaft end of the fan blade passes through the cylinder cover and is fixedly connected to an inner magnetic rotor, a non-magnetic isolation sleeve is fixedly connected to the outside of the air chamber, and an outer magnetic rotor adapted to the inner magnetic rotor is rotatably connected inside the non-magnetic isolation sleeve.

[0015] Preferably, a motor is fixedly connected to the outside of the non-magnetic isolation sleeve, the shaft end of the outer magnetic rotor passes through the non-magnetic isolation sleeve and is fixedly connected to the output end of the motor, and a guide air vent is provided on the top of the cylinder cover.

[0016] The beneficial effects of this invention are: 1. This invention utilizes bellows pressure differential sensing to drive the piston cylinder to rapidly withdraw under extreme overload conditions, removing its obstruction to the air inlet and outlet, forming a low-resistance, direct-flow air duct within the dehumidification chamber. This causes a sudden surge in the total air volume blown out by the fan blades, and suppresses the excessive outward migration of resin moisture through extreme forced convection heat dissipation. When the load decreases or the temperature drops sharply at night, the mechanism reverses and quickly rebuilds the closed air duct. Utilizing the highly efficient desorption and regeneration of the strong molecular sieve, it forcefully draws out free moisture from the gas before the gas reaches its saturation dew point, disrupting the conditions for liquid condensation formation and ensuring dielectric insulation safety under environmentally friendly media with low insulation tolerance.

[0017] 2. This invention uses an active rod and a transmission roller to actuate a driven rod, converting the slow linear displacement of the bellows into the elastic potential energy of a tension spring. Once the collinear dead point is crossed, the tension spring potential energy is released instantaneously. Through the mechanical meshing of the transmission gear and the transmission rack, the piston cylinder is driven to jump and shift, realizing a rapid switch in the airflow direction. This ensures a clean and crisp switching action between the exhaust port and the circulating air duct, eliminating the potential for airflow contamination during intermediate transitions. Simultaneously, this mechanism utilizes a passive mechanical jump action to drive the molecular sieve, achieving green and energy-saving cyclic desorption and regeneration.

[0018] 3. This invention uses an external magnetic rotor, a non-magnetic isolation sleeve, and an internal magnetic rotor to achieve contactless magnetic attraction, seamlessly delivering the mechanical torque of the external motor into the sealed gas chamber to drive the fan blades. This transforms the dynamic seal into a reliable static seal with a fixed static sealing wall panel, completely eliminating the hidden dangers of wear and leakage associated with traditional shaft seals. In dehumidification and regeneration, the molecular sieve is rigidly isolated as it is drawn out with the piston cylinder, ensuring that the arc heater and low-voltage electrical cables are safely located outside the gas chamber. This avoids the risk of local overheating inside the cabinet leading to thermal decomposition of high-purity nitrogen and degradation of dielectric strength, and also eliminates the hidden dangers of electric field distortion and surface discharge caused by low-voltage leads passing through the wall.

[0019] 4. This invention incorporates a variable-capacity pressure-maintaining unit, utilizing a bellows to spontaneously sense temperature and pressure changes within the gas chamber: when temperature rises leading to increased gas pressure, the bellows axially contracts, correspondingly expanding the effective gas volume of the chamber. This volume compensation slows down the pressure rise rate within the chamber, buffering transient high pressure. When temperature drops leading to decreased gas pressure, the bellows extends in the opposite direction, synchronously reducing the effective gas volume of the chamber. This reverse volume compression compensation suppresses negative pressure within the chamber, effectively preventing external moisture from intruding into the chamber along the seams. Simultaneously, the variable-capacity pressure-maintaining unit generates displacement through its own morphological expansion and contraction, providing driving force for the subsequent jump triggering unit. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a front view of the ring main unit in this invention; Figure 2 This is a side view of the ring main unit in this invention; Figure 3 This is a schematic diagram of the internal structure of the air chamber in this invention; Figure 4 This is a schematic diagram of the internal structure of the guide chamber in this invention; Figure 5 This is a schematic diagram of the internal structure of the dehumidification chamber in this invention; Figure 6 This is a schematic diagram of the internal structure of the dehumidification port in this invention; Figure 7 This is an exploded view of the internal structure of the piston cylinder in this invention; Figure 8 This is a schematic diagram showing the installation positions of the driven rod and the transmission roller in this invention; Figure 9 This is a schematic diagram of the internal structure of the non-magnetic isolation sleeve in this invention.

[0021] The following labels are used in the attached diagram: 1. Ring main unit body; 2. Air chamber; 3. Dehumidification chamber; 4. Piston cylinder; 5. Molecular sieve; 6. Exhaust port; 7. Air inlet; 8. Ventilation port; 9. Regeneration port; 10. Arc heater; 11. Guide chamber; 12. Bellows; 13. T-shaped guide rod; 14. Return spring; 15. Guide groove; 16. Guide slide rod; 17. Driving rod; 18. Transmission roller; 19. Transmission gear; 20. Driven rod; 21. Hook rod; 22. Tension spring; 23. Transmission groove; 24. Transmission slider; 25. Transmission rack; 26. Air outlet; 27. Cover; 28. Fan blade; 29. ​​Inner magnetic rotor; 30. Non-magnetic isolation sleeve; 31. Outer magnetic rotor; 32. Motor; 33. Air guide outlet. Detailed Implementation

[0022] 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.

[0023] Energy-saving and environmentally friendly medium-voltage ring network switchgear is mainly designed for the construction of smart grids and new power system distribution networks. It is suitable for the requirements of the switch being enclosed in a housing or the switch and housing being integrated. It is used to meet the core green and energy-saving application requirements of enclosed switchgear under long-term operation, such as high-reliability insulation, forced convection heat dissipation and active dehumidification. It utilizes the coordinated operation of a variable-capacity pressure-holding unit, a sudden-jump triggering unit, and a convection dehumidification unit, with the internal pressure fluctuation caused by the temperature rise of the gas chamber itself as the sole driving force. On the one hand, it effectively solves the insulation protection problems of traditional closed switchgear using environmentally friendly gas media, such as low resistance to liquid surface condensation insulation, heat-induced precipitation and migration of deeply adsorbed moisture inside epoxy resin solid insulation components, and surface condensation flashover caused by misalignment of solid and gas cooling sequences during the cooling period. On the other hand, it eliminates the mechanical operation defects of traditional gas valves when slowly displaced by pressure swing, which lead to leakage of insulating gas and obstruction of air ducts due to the existence of intermediate dead zones. This solution achieves instantaneous rigid sudden-jump switching of the flow channel boundary through pure mechanical linkage, enabling conventional closed dehumidification and extreme direct-flow high-volume heat dissipation to be linked as needed; and under extreme temperature rise conditions, it drives the molecular sieve in the convection dehumidification unit to move out of the gas chamber for heating and desorption, completely discharging the adsorbed moisture to the outside atmosphere, achieving efficient regeneration of the molecular sieve. When the load drops or the temperature drops suddenly at night, this equipment reverses and rigidly rebuilds the closed air duct. Utilizing the regenerated high-efficiency molecular sieve, it forcefully draws out the free moisture in the air chamber before the environmentally friendly gas reaches its saturation dew point, thereby destroying the conditions for the formation of liquid condensation from the source and ensuring the dielectric insulation safety of the system under environmentally friendly media with low insulation tolerance.

[0024] like Figures 1-9 As shown, it includes a ring main unit 1, and an air chamber 2 is provided inside the ring main unit 1. The air chamber 2 is provided with a variable capacity pressure holding unit, a sudden triggering unit and a convection dehumidification unit. The convection dehumidification unit includes a cylindrical dehumidification chamber 3 located at the bottom of the air chamber 2, a piston cylinder 4 slidably disposed inside the dehumidification chamber 3, and a molecular sieve 5 filled inside the piston cylinder 4; The variable capacity pressure holding unit is used to sense the temperature and pressure changes inside the gas chamber 2 and generate morphological expansion and contraction; The jump trigger unit is connected between the variable capacity pressure holding unit and the piston cylinder 4. When the variable capacity pressure holding unit expands and contracts to a preset extent, it drives the piston cylinder 4 to move along the axial direction of the dehumidification chamber 3, thereby realizing the switching of different working conditions of the convection dehumidification unit. Among them, one end of the dehumidification chamber 3 extends to the outside of the air chamber 2 and has a dehumidification port 6 at the extended end; the end of the dehumidification chamber 3 located inside the air chamber 2 has an air inlet 7 and is equipped with a convection component. One end of the piston cylinder 4 is symmetrically provided with ventilation ports 8 that are adapted to the air inlet 7 and the convection assembly respectively, and the other end of the piston cylinder 4 is provided with a regeneration port 9 that is adapted to the dehumidification port 6. Furthermore, the convection dehumidification unit also includes an arc heater 10, which is disposed on the inner wall of one end of the dehumidification chamber 3 extending to the outside of the air chamber 2, and the arc heater 10 is sleeved on the outer periphery of the piston cylinder 4. Furthermore, the variable capacity pressure holding unit includes a guide chamber 11, a bellows 12, a T-shaped guide rod 13, and a return spring 14; The guide chamber 11 is located at the bottom of the air chamber 2 and its interior is connected to the interior of the air chamber 2. The bellows 12 is located inside the guide chamber 11 and its interior is sealed and filled with atmospheric pressure air. The T-shaped guide rod 13 is arranged along the axial direction of the guide chamber 11 and is fixedly connected to the end of the bellows 12. One end of the T-shaped guide rod 13 passes through the guide chamber 11 and is slidably connected to the guide chamber 11. The return spring 14 is sleeved on the outer periphery of the T-shaped guide rod 13 and is located between the T-shaped guide rod 13 and the guide chamber 11.

[0025] Among them, a guide groove 15 is provided on one side of the guide chamber 11 along the axial direction, and the jump trigger unit includes a guide slide rod 16, an active rod 17 and a pair of transmission rollers 18; The guide slide rod 16 is fixedly connected to one end of the T-shaped guide rod 13 that protrudes from the guide chamber 11, and one end of the guide slide rod 16 passes through the guide groove 15 and is fixedly connected to the drive rod 17. A pair of transmission rollers 18 are arranged at one end of the drive rod 17. Furthermore, the jump trigger unit also includes a transmission gear 19 and a driven rod 20; The transmission gear 19 is rotatably connected inside the air chamber 2, and the driven rod 20 is fixedly connected to the shaft end of the transmission gear 19, with its end positioned between a pair of transmission rollers 18. A hook rod 21 is fixedly installed in the middle section of the driven rod 20. One end of the hook rod 21 is hooked with a tension spring 22, and the other end of the tension spring 22 is hooked with the inner wall of the air chamber 2. Furthermore, a transmission groove 23 is provided on one side of the dehumidification chamber 3, and a transmission slider 24 is fixedly connected to the middle section of the piston cylinder 4. One end of the transmission slider 24 passes through the transmission groove 23 and is fixedly connected to a transmission rack 25. The transmission rack 25 meshes with the transmission gear 19. Furthermore, the convection assembly includes an air outlet 26 and a cylindrical cover 27. The air outlet 26 and the air inlet 7 are coaxially opposite each other. The cylindrical cover 27 is located at the output end of the air outlet 26. A fan blade 28 is rotatably arranged inside the cylindrical cover 27. Furthermore, the shaft end of the fan blade 28 passes through the cylinder cover 27 and is fixedly connected to the inner magnetic rotor 29. A non-magnetic isolation sleeve 30 is fixedly connected to the outside of the air chamber 2. An outer magnetic rotor 31 adapted to the inner magnetic rotor 29 is rotatably connected inside the non-magnetic isolation sleeve 30. Furthermore, a motor 32 is fixedly connected to the outside of the non-magnetic isolation sleeve 30, and the shaft end of the external magnetic rotor 31 passes through the non-magnetic isolation sleeve 30 and is fixedly connected to the output end of the motor 32. A guide air vent 33 is provided on the top of the cylinder cover 27.

[0026] During use, firstly, under normal rated operating conditions, the air chamber 2 is in a normal reference pressure and temperature state due to normal electrical load. At this time, the bellows 12 is kept in an axially extended state under the joint support of the internal sealed air and the outer peripheral return spring 14. The guide slide 16 is pushed to the outermost position of the guide slide groove 15 by the T-shaped guide rod 13. The two sets of transmission rollers 18 at the top of the active rod 17 stably limit the driven rod 20 to the initial angle. The tension spring 22 is in a normal relaxed state on the dead point side. The transmission gear 19 is kept in the original position. The piston cylinder 4 is rigidly positioned at the innermost stroke of the cylindrical dehumidification chamber 3 by the transmission rack 25 and the transmission slider 24. At this time, the vent 8 on the piston cylinder 4 is completely aligned and connected with the air inlet 7 and air outlet 26 on the wall of the dehumidification chamber 3. The exhaust port 6 at the end of the dehumidification chamber 3 is tightly sealed by the blind section of the piston cylinder 4, forming a closed circulation air duct inside the air chamber 2. During this process, the motor 32 drives the outer magnetic rotor 31 to rotate synchronously, and the magnetic lines of force penetrate the non-magnetic isolation sleeve 30 to forcibly pull the inner magnetic rotor 29 in the air chamber, driving the fan blades 28 to run and draw air; the high-purity nitrogen and other environmentally friendly insulating gases in the air chamber 2 are drawn in through the air inlet 7, pass laterally through the molecular sieve 5, and continuously absorb the trace amounts of deep-adsorbed moisture released by the deep migration of solid insulating components such as epoxy resin in the air chamber 2, thus completing the dehumidification and drying of the gas itself; then the dehumidified dry gas is drawn out from the air outlet 26 and sprayed directionally through the guide air outlet 33 to the busbar joint, switch contacts and other core heat-generating components and areas prone to condensation, using the circulating dry airflow to simultaneously flush and dissipate heat and remove moisture, which can not only specifically remove the heat generated by the operation of electrical components, reduce local temperature rise, and slow down the rate of moisture migration from the inside of solid insulating components, but also destroy the conditions for condensation formation, thus taking into account both conventional heat dissipation and dehumidification effects; at this time, the arc heater 10 is in a power-off and shutdown state; When the busbar inside the cabinet is overloaded, the contact resistance increases, or the temperature inside air chamber 2 rises sharply due to exposure to direct sunlight, the insulating gas expands due to heat, and the gas pressure exceeds the normal reference value. Driven by the gas pressure, the mechanical mechanism switches to the heating and dehumidification and direct heat dissipation state. First, high-pressure gas rushes into the guide chamber 11 and squeezes the bellows 12 inward, overcoming the combined elastic force of the normal-pressure air inside and the return spring 14, forcing the bellows 12 to contract axially, pulling the T-shaped guide rod 13 back into the guide chamber 11; the guide slide rod 16 slides along the guide groove 15, driving the driving rod 17 and the transmission roller 18 at the end to move horizontally in a straight line, and through rolling friction, it drives the driven rod 20 to slowly rotate around the axis of the transmission gear 19, pulling the hook rod 21 to gradually cause the tension spring 22 to gradually... Stretching and storing energy; once the driven rod 20 is pushed past the collinear dead point, the direction of the elastic tension of the tension spring 22 changes abruptly, and the accumulated mechanical potential energy bursts and is released instantly. The hook rod 21 pulls the driven rod 20 to swing at high speed, causing the transmission gear 19 to generate a rigid jump rotation; the transmission rack 25 meshing with the transmission gear 19 is driven by a huge tangential force, and moves in the transmission groove 23 through the transmission slider 24, pulling the piston cylinder 4 outward instantly to the outermost stroke, changing the air passage connection direction; Based on the actual pressure fluctuation and pressurization rate inside chamber 2, the above-mentioned pressure swing linkage process specifically includes the following different operating conditions in actual operation: When the pressure in air chamber 2 increases slowly and gradually due to continuous high-load operation during the day, and the increase is close to the action threshold, the bellows 12 continues to contract as the air pressure rises, so that the effective gas volume of air chamber 2 gradually expands to buffer the pressure rise, until the tension spring 22 crosses the collinear dead point and generates a mechanical jump; after the piston cylinder 4 slides into place instantly, the blind section of its wall immediately cuts off the air inlet 7 and the air outlet 26, completely isolating the internal space of the dehumidification chamber 3 from the air chamber 2, while the regeneration port 9 and the exhaust port 6 are precisely connected; at this time, the arc heater 10 heats up, and the heat is conducted to the molecular sieve 5, causing the adsorbed moisture to vaporize violently, and the steam formed is sprayed directly from the exhaust port 6 to the atmosphere outside the ring network cabinet body 1 through the regeneration port 9, realizing deep thermal desorption and regeneration without backflow; When the air chamber 2 encounters extreme overload or sudden strong current impact, causing a sharp increase in heat generation and an instantaneous surge in air pressure, the high-pressure gas violently impacts the bellows 12, compressing it to the bottom in a very short time. At this time, the bellows 12 is axially compressed to its limit position, reducing the volume it occupies in the air chamber 2 to the minimum value. The effective gas volume of the air chamber 2 instantly expands to the maximum value, unloading the transient high-pressure peak through volume compensation. During its axial compression, its mechanical displacement synchronously drives the transmission chain to cross the dead point with extremely high acceleration and complete the jump. The piston cylinder 4 completes the external extraction at the fastest speed. At this time, the cylinder body of the piston cylinder 4 completely withdraws from the blocking area between the air inlet 7 and the air outlet 26, allowing the air inlet 7 and the air outlet 26 to be directly open and communicated inside the dehumidification chamber 3. Since the circulating airflow no longer needs to pass through the dense molecular sieve 5 inside the piston cylinder 4, the molecular sieve 5 filter layer, which serves as a resistance source in the dehumidification chamber 3, is removed from the air duct, significantly reducing the local resistance and friction resistance in the entire circulating air path. Under the continuous drive of the fan blades 28, the reduced flow resistance causes a sudden increase in the gas circulation velocity and total air volume of the environmentally friendly insulating gas in the air chamber 2. In this state, the high-velocity insulating gas is guided to the core heating area through the guide air outlet 33. The high-speed airflow significantly reduces the convective heat transfer resistance on the surface of the heating element, improving the convective heat transfer coefficient between the gas and the core heating area, allowing the heat from the core heating area to be quickly transferred to the circulating gas. At the same time, the convective scouring of the high-velocity gas forcibly breaks the static temperature of the fluid inside the air chamber 2. Layering rapidly disperses and eliminates local heat accumulation around the core heating area, achieving rapid homogenization of the temperature field of the insulating gas inside the air chamber 2, and reducing the local peak temperature rise of the core heating component; driven by the fan blades 28, the high-temperature insulating gas that has absorbed heat and been homogenized and mixed forms a large-scale high-speed convection circulation inside the air chamber 2. The high-velocity airflow flows through and violently washes the inner surface of the metal outer wall of the air chamber 2, significantly improving the convective heat transfer coefficient between the gas and the inner surface of the metal outer wall of the air chamber 2, thereby enabling the heat in the insulating gas to be rapidly conducted through the metal outer wall of the air chamber 2 and dissipated into the air outside the ring main unit 1, forming an efficient heat dissipation path from the core heating area - circulating gas - metal outer wall of the air chamber 2 - external air; At the same time, the molecular sieve 5, which is isolated by external extraction, is heated by the arc heater 10 at the outer end of the dehumidification chamber 3. The vaporized moisture is discharged directly to the atmosphere outside the ring network cabinet body 1 through the exhaust port 6. The direct low-resistance air duct perfectly balances the extreme large air volume heat dissipation and the uninterrupted dehumidification.

[0027] When the ring main body 1 is under load reduction, nighttime temperature drop, or severe winter conditions, the internal temperature of the air chamber 2 continues to decrease. The volume of the environmentally friendly insulating gas shrinks, causing the air pressure to drop significantly and fall below the benchmark value. When the external pressure subsides, the bellows 12 rebounds and elongates outwards under the combined action of the internal atmospheric pressure air and the release force of the return spring 14. At this time, the volume occupied by the bellows 12 in the air chamber 2 increases, causing the effective gas volume of the air chamber 2 to shrink synchronously. This provides reverse volume compression compensation for the cooling and shrinking insulating gas, suppressing the negative pressure generated in the air chamber 2 due to temperature drop. During the axial elongation of the bellows 12, its displacement synchronously pushes the T-shaped guide rod 13 and guide slide rod 16 to slide out in the opposite direction. The active rod 17 pulls the driven rod 20 to rotate in the opposite direction, causing the tension spring 22 to stretch and store energy in the opposite direction, crossing the dead zone. After the point, a reverse mechanical jump occurs, driving the transmission gear 19 and transmission rack 25 to push the piston cylinder 4 back to its initial position instantly; at this time, the arc heater 10 is de-energized and cooled, the exhaust port 6 is re-locked and sealed, the ventilation port 8 is reconnected to the air inlet 7 and the air outlet 26, and a closed-loop air duct is formed again; the fan blades 28 continue to run and draw air, guiding the airflow to circulate again with a large volume, spraying the cold airflow at high frequency onto core components such as large-volume epoxy resin solid insulation parts, eliminating the misalignment of the cooling sequence of solid and gas and accelerating the heat dissipation of solid parts, while using the highly efficient molecular sieve 5, which is in an extremely dry state after desorption and regeneration, to quickly draw out the free water suspended in the insulating gas before the gas reaches the saturated dew point, fundamentally eliminating the possibility of condensation flashover accidents on the surface of insulation parts due to sudden temperature drop; When the ring main body 1 is under extremely low load or seasonal normal temperature operation for a long time, the overall heat generation inside the cabinet is extremely low and the air pressure is stable at the standard baseline all year round, the whole mechanism is stable in the normal dehumidification and heat dissipation state: the bellows 12 remains in place without deformation, the tension spring 22 remains on the normal dehumidification side, the piston cylinder 4 is stationary at the inner end stroke, keeping the basic air duct unobstructed; the arc heater 10 is kept in the de-energized state, the fan blades 28 maintain the basic speed operation, and rely on micro-convection to continuously dissipate basic heat from the core terminal, and maintain the dynamic balance of the dry environment in the air chamber 2, taking into account the normal heat dissipation and moisture prevention requirements.

[0028] The working principle of the energy-saving and environmentally friendly medium-voltage ring network switchgear provided by this invention is as follows: Firstly, in switchgear using environmentally friendly gases such as high-purity nitrogen as the insulating medium, the dielectric's resistance to liquid condensation on the surface is far lower than that of sulfur hexafluoride. Furthermore, the numerous epoxy resin solid insulation components used internally readily migrate and release deeply adsorbed moisture during operation, leading to a disconnect between dehumidification and heat dissipation in conventional ring main units. Conventional technology relies on built-in heaters for in-situ static baking, causing the evaporated moisture to circulate secondaryly within the sealed gas chamber 2. This exacerbates surface condensation caused by the misalignment of solid and gas cooling sequences during nighttime cooling.

[0029] This solution introduces a passive jump transmission mechanism based on the differential pressure sensing of the bellows 12 and the dead point crossing of the tension spring 22. It relies solely on the pressure swing caused by the temperature rise of the air chamber 2 itself as the main driving force, achieving passive hard switching of the air path boundary. Under normal operating conditions, the ventilation port 8 of the mechanism-driven piston cylinder 4 is completely aligned and connected with the air inlet 7 and air outlet 26 on the wall of the dehumidification chamber 3. At this time, the circulating airflow drawn by the fan blades 28 has a dual function of heat dissipation and dehumidification: when the airflow passes laterally through the molecular sieve 5, it continuously absorbs trace amounts of deeply adsorbed moisture released by solid insulating components such as epoxy resin, converting it into extremely dry gas; subsequently, this airflow is guided to the core heat-generating areas such as the busbar and contacts, where forced convection carries away the working heat of electrical components while the drying medium disrupts condensation conditions, achieving a dynamic balance between heat dissipation and dehumidification.

[0030] When the ring main unit 1 experiences extreme overload and temperature rise, causing the air pressure in the air chamber 2 to surge and cross the mechanical dead point, the potential energy accumulated by the tension spring 22 is released instantly, driving the piston cylinder 4 to quickly pull outward. At this time, the air inlet 7 and air outlet 26, which were originally blocked by the piston cylinder 4, are directly open and connected inside the dehumidification chamber 3, forming a low-resistance direct air duct that does not need to pass through the molecular sieve 5. This causes the environmentally friendly insulating gas blown out by the fan blades 28 to have a sudden increase in circulation velocity and total air volume due to the significant reduction in flow resistance. This high-velocity gas rushes towards the core heat-generating areas such as the busbar joints and switch contacts, significantly reducing the convective heat transfer resistance on the surface of the heat-generating elements. During this process, the high-velocity gas convection forcefully breaks the static temperature stratification of the fluid inside chamber 2, rapidly dispersing and eliminating local heat accumulation around the core heating area, achieving rapid homogenization of the insulating gas temperature field inside chamber 2, and reducing the local peak temperature rise of the core heating components. Simultaneously, the high-volume, high-velocity airflow forms a high-speed convection circulation inside chamber 2, strongly scouring the inner surface of the metal outer wall of chamber 2, significantly increasing the convective heat transfer coefficient from the internal insulating gas to the outer wall, allowing heat to be rapidly conducted and dissipated through the metal outer wall of chamber 2 to the ring main unit 1. In the external air, the overall heat dissipation efficiency of the system is improved in a very short time, the extreme temperature rise is quickly suppressed, and the large amount of migration and release of moisture deeply adsorbed by the resin under high heat is inhibited from the source. At the same time, the molecular sieve 5 drawn to the edge is baked by the arc heater 10 at the independent exhaust port 6. The desorbed moisture is discharged directly from the exhaust port 6 to the atmosphere outside the ring network cabinet body 1 through the regeneration port 9. There is no need to worry about moisture flowing back into the air chamber 2. The unobstructed direct ventilation channel solves the extreme heat dissipation problem under extreme working conditions, and achieves the on-demand linkage of high-power heat dissipation and thorough dehumidification. When the load drops and the temperature drops sharply at night, the mechanism relies on the reverse mechanical jump to drive the piston cylinder 4 to push back and relock the exhaust port 6, re-establish the closed circulation air channel, and use the high-efficiency molecular sieve 5 after desorption and regeneration to strongly draw free moisture in high-purity nitrogen gas. Before the gas reaches the saturation dew point, the potential for surface condensation caused by the misalignment of solid and gas cooling sequence is eliminated, ensuring the dielectric insulation safety of the system.

[0031] Next, the mechanical torque input from the external motor 32 is delivered into the sealed gas chamber 2 without contact through the magnetic lines of force penetration attraction between the external magnetic rotor 31, the non-magnetic isolation sleeve 30 outside the ring main unit 1, and the internal magnetic rotor 29 inside the unit, driving the fan blades 28 to run. Compared with the traditional dynamic seal shaft seal structure, this solution transforms the dynamic mating surface, which is extremely prone to wear, aging, and leakage, into an absolutely sealed solid static seal wall panel, completely eliminating the potential for disorderly leakage of environmentally friendly gases during long-term operation.

[0032] Finally, under the condition of external hard isolation driven by the piston cylinder 4, the arc heater 10 is activated. The heating components and low-voltage secondary electrical cables are all located outside the gas chamber 2. This avoids the risk of thermal decomposition and decreased dielectric strength of the high-purity nitrogen gas inside the cabinet due to local overheating of the internal heating surface, and also eliminates the electric field distortion and surface discharge hazards caused by the low-voltage leads passing through the wall. When the temperature drops and the mechanism reverses and resets, the piston cylinder 4 is instantly pushed back and relocks the exhaust port 6. The closed-loop air duct is switched back on, allowing the desorbed and regenerated high-efficiency molecular sieve 5 to immediately resume operation.

[0033] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. Energy-saving and environment-friendly medium-voltage ring network switch device, characterized in that: The ring main unit (1) includes an air chamber (2) inside the ring main unit (1), and the air chamber (2) is equipped with a variable capacity pressure holding unit, a sudden jump triggering unit and a convection dehumidification unit. The convection dehumidification unit includes a cylindrical dehumidification chamber (3) located at the bottom of the air chamber (2), a piston cylinder (4) is slidably arranged inside the dehumidification chamber (3), and the piston cylinder (4) is filled with molecular sieve (5). The variable capacity pressure holding unit is used to sense the temperature and pressure changes inside the gas chamber (2) and generate morphological expansion and contraction; The jump trigger unit is connected between the variable capacity pressure holding unit and the piston cylinder (4) and is used to drive the piston cylinder (4) to move along the axial direction of the dehumidification chamber (3) when the variable capacity pressure holding unit expands and contracts to a preset degree, so as to realize the switching of different working conditions of the convection dehumidification unit.

2. The energy-saving and environmentally friendly medium-voltage ring network switchgear according to claim 1, characterized in that: One end of the dehumidification chamber (3) extends to the outside of the air chamber (2) and has a dehumidification port (6) at the extended end. The dehumidification chamber (3) is located inside the air chamber (2) and has an air inlet (7) and a convection component at one end. One end of the piston cylinder (4) is symmetrically provided with ventilation openings (8) adapted to the air inlet (7) and the convection assembly respectively, and the other end of the piston cylinder (4) is provided with a regeneration port (9) adapted to the dehumidification port (6).

3. The energy-saving and environmentally friendly medium-voltage ring network switchgear according to claim 2, characterized in that: The convection dehumidification unit also includes an arc heater (10), which is disposed on the inner wall of one end of the dehumidification chamber (3) extending to the outside of the air chamber (2), and the arc heater (10) is sleeved on the outer periphery of the piston cylinder (4).

4. The energy-saving and environmentally friendly medium-voltage ring network switchgear according to claim 1, characterized in that: The variable capacity pressure holding unit includes a guide chamber (11), a bellows (12), a T-shaped guide rod (13), and a return spring (14). The guide chamber (11) is located at the bottom of the air chamber (2) and its interior is connected to the interior of the air chamber (2). The bellows (12) is located inside the guide chamber (11) and its interior is sealed and filled with atmospheric pressure air. The T-shaped guide rod (13) is arranged along the axial direction of the guide chamber (11) and fixed to the end of the bellows (12). One end of the T-shaped guide rod (13) passes through the guide chamber (11) and is slidably connected to the guide chamber (11). The reset spring (14) is sleeved on the outer periphery of the T-shaped guide rod (13) and is located between the T-shaped guide rod (13) and the guide chamber (11).

5. The energy-saving and environmentally friendly medium-voltage ring network switchgear according to claim 4, characterized in that: The guide chamber (11) has a guide groove (15) axially opened on one side, and the jump trigger unit includes a guide slide rod (16), an active rod (17) and a pair of transmission rollers (18). The guide slide rod (16) is fixedly connected to one end of the T-shaped guide rod (13) that passes through the guide chamber (11), and one end of the guide slide rod (16) passes through the guide groove (15) and is fixedly connected to the drive rod (17). A pair of transmission rollers (18) are set at one end of the drive rod (17).

6. The energy-saving and environmentally friendly medium-voltage ring network switchgear according to claim 5, characterized in that: The jump triggering unit also includes a transmission gear (19) and a driven rod (20). The transmission gear (19) is rotatably connected inside the air chamber (2), and the driven rod (20) is fixedly connected to the shaft end of the transmission gear (19) with its end set between a pair of transmission rollers (18). A hook rod (21) is fixedly installed in the middle section of the driven rod (20). One end of the hook rod (21) is hooked with a tension spring (22), and the other end of the tension spring (22) is hooked with the inner wall of the air chamber (2).

7. The energy-saving and environmentally friendly medium-voltage ring network switchgear according to claim 6, characterized in that: The dehumidification chamber (3) has a transmission groove (23) on one side. The piston cylinder (4) is fixedly connected to a transmission slider (24). One end of the transmission slider (24) passes through the transmission groove (23) and is fixedly connected to a transmission rack (25). The transmission rack (25) meshes with the transmission gear (19).

8. The energy-saving and environmentally friendly medium-voltage ring network switchgear according to claim 2, characterized in that: The convection assembly includes an air outlet (26) and a shroud (27). The air outlet (26) and the air inlet (7) are coaxially opposite each other. The shroud (27) is located at the output end of the air outlet (26). A fan blade (28) is rotatably arranged inside the shroud (27).

9. The energy-saving and environmentally friendly medium-voltage ring network switchgear according to claim 8, characterized in that: The shaft end of the fan blade (28) passes through the sleeve (27) and is fixedly connected to the inner magnetic rotor (29). A non-magnetic isolation sleeve (30) is fixedly connected to the outside of the air chamber (2). An outer magnetic rotor (31) that is compatible with the inner magnetic rotor (29) is rotatably connected inside the non-magnetic isolation sleeve (30).

10. The energy-saving and environmentally friendly medium-voltage ring network switchgear according to claim 9, characterized in that: A motor (32) is fixedly connected to the outside of the non-magnetic isolation sleeve (30). The shaft end of the external magnetic rotor (31) passes through the non-magnetic isolation sleeve (30) and is fixedly connected to the output end of the motor (32). A guide air vent (33) is provided on the top of the cylinder cover (27).

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