Self-adaptive protection device for ring main unit

Abstract

The application relates to the technical field of ring network cabinets, and provides a self-adaptive protection device for a ring network cabinet, which comprises a cabinet body, a gas tank filled with environment-friendly insulation gas and installed at the back of the cabinet body, and a pressure relief pipe communicated with the top of the gas tank and used for pressure relief of the gas tank; a pressure relief control assembly is installed at the top of the gas tank; the top of the pressure relief control assembly is provided with a dustproof assembly; the pressure relief control assembly comprises a funnel-shaped main speed discharge cylinder arranged at the top of the gas tank and a butt joint sleeve pipe sealingly connected with the main speed discharge cylinder. In use, the main pressure relief channel and the branch slow heat pressure relief channel are utilized, and the main pressure relief channel and the branch slow heat pressure relief channel respectively respond to instantaneous high pressure impact and persistent heat pressure, so that deformation and damage of the gas tank caused by instantaneous arc overvoltage are effectively prevented, hidden dangers caused by pressure accumulation due to abnormal slow heating and unable to be timely discharged are eliminated, and self-adaptive protection of the gas tank of the ring network cabinet is realized.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of ring main units, in particular to a self-adaptive protection device for a ring main unit. BACKGROUND

[0002] As one of important types of ring main units, the environmentally-friendly gas insulated ring main unit is an environmentally-friendly gas fully insulated metal enclosed switchgear widely used in the power system transmission and distribution field, which is internally provided with a primary loop insulation chamber, and the chamber is internally provided with electrical elements and filled with environmentally-friendly gas as insulation medium, so that the safe and stable operation of the power grid can be effectively ensured.

[0003] At present, the insulation chamber gas tank of the environmentally-friendly gas insulated ring main unit is usually provided with a rupture disc with a fixed action threshold based on standard atmospheric pressure as a pressure relief device, when an arc fault occurs in the chamber to cause the gas pressure to suddenly rise and reach the preset burst pressure, the rupture disc will be broken to realize safe pressure relief.

[0004] However, the existing fixed threshold rupture disc is difficult to cope with the abnormal temperature rise and slow pressure rise of the insulation chamber gas tank caused by the aging, failure or sealing failure of the electrical elements in the cabinet, and cannot timely relieve the pressure when the threshold is not reached, which buries the structural safety hazard of cabinet deformation, and the more prominent problem is that it cannot adapt to the atmospheric environment in high altitude areas, because the external atmospheric pressure is significantly lower than the standard atmospheric pressure, and the fixed pressure relief threshold will cause the rupture disc to frequently malfunction under normal working conditions due to the increase of the pressure difference between the inside and outside of the cabinet, which seriously damages the air tightness of the equipment, affects the continuity of power supply and increases the operation and maintenance cost.

[0005] Therefore, the application provides a self-adaptive protection device for a ring main unit to solve the above problems. SUMMARY

[0006] The technical problem to be solved: in view of the problems in the prior art, the purpose of the application is to provide a self-adaptive protection device for a ring main unit, which solves the problems of slow pressure relief of the existing fixed threshold rupture disc in the cabinet and easy malfunction in high altitude environment due to pressure difference.

[0007] To solve the above technical problems, the application provides the following technical scheme: a self-adaptive protection device for a ring main unit, comprising a cabinet body, a gas tank installed at the back of the cabinet body and filled with environmentally-friendly insulation gas inside, and a pressure relief pipe communicated with the top of the gas tank and used for pressure relief of the gas tank; a pressure relief control assembly is installed at the top of the gas tank, and a dustproof assembly is installed at the top of the pressure relief control assembly; the pressure relief control assembly comprises a funnel-shaped main speed discharge cylinder arranged at the top of the gas tank, a butt joint pipe sealingly connected with the main speed discharge cylinder and the pressure relief pipe, and hot slow discharge cylinders symmetrically installed at both sides of the main speed discharge cylinder and communicated with the funnel inclined surface of the main speed discharge cylinder; the main speed discharge cylinder and the hot slow discharge cylinder correspond to two protection positions: when instantaneous high pressure is generated in the gas tank due to arc fault, the main speed discharge cylinder rapidly opens a main pressure relief channel in response to high pressure impact; when persistent thermal pressure is generated in the gas tank due to abnormal slow heating, the hot slow discharge cylinder triggers to open a branch pressure relief channel in response to the joint action of heat and pressure.

[0008] In a new embodiment, a main pressure relief assembly is arranged in the main speed discharge cylinder, the main pressure relief assembly comprises a cross base, a center column and an inverted cone sliding table block; the cross base is fixedly installed at the upper side inside the main speed discharge cylinder, a center column with a length equal to that of the main speed discharge cylinder is vertically installed at the bottom of the cross base, the inverted cone sliding table block is slidably arranged on the center column, and the top of the inverted cone sliding table block is connected with the bottom of the cross base through a return spring; the inverted cone sliding table block is sealingly and slidably matched with the inner wall of the lower tubular section of the main speed discharge cylinder, and an insulation cone sleeve is arranged outside the inverted cone sliding table block; a shielding ring is connected with the lower part of the inverted cone sliding table block through two insulation connecting rods, and the shielding ring is sealingly and slidably matched with the inner wall of the lower tubular section of the main speed discharge cylinder; when the inverted cone sliding table block is moved upward under high pressure impact, the shielding ring is moved upward and shields the communication port between the hot slow discharge cylinder and the main speed discharge cylinder.

[0009] In a new embodiment, an auxiliary pressure relief assembly is arranged in the hot slow discharge cylinder, the auxiliary pressure relief assembly comprises a suspension outer cylinder, a plugging top column and a valve seat ring; the suspension outer cylinder is installed at the upper side inside the hot slow discharge cylinder; the valve seat ring is installed at the lower side inside the hot slow discharge cylinder, and the bottom of the valve seat ring is arranged in an inclined annular surface; a plugging top column is slidably arranged in the suspension outer cylinder, locking grooves are formed at the two sides of the plugging top column, the top end of the plugging top column is further connected with the convex ring at the upper part of the inner wall of the suspension outer cylinder through a weak spring, and the lower rod body of the plugging top column is slidably and sealingly matched with the through hole in the middle part of the valve seat ring and used for plugging the through hole; hot flow pipes are installed at the two sides of the middle part of the valve seat ring, a heat-sensitive driving mechanism is arranged in the hot flow pipes, and the heat-sensitive driving mechanism acts when heated to release the locking of the plugging top column.

[0010] In a new embodiment, the thermally sensitive driving mechanism includes a heated metal sheet and a locking pin; the heated metal sheet is installed on the upper part of the outer wall of the heat flow pipe, and expands and deforms in the direction of the outer side of the heat flow pipe when heated; one end of the locking pin is connected to the heated metal sheet and moves with its deformation, and the other end passes through and slides on the upper part of the inner wall of the heat flow pipe; the locking pin is adapted to the locking groove located on the sealing top pin.

[0011] In a new embodiment, a first electromagnetic ring is installed at the bottom of the cross base, and a first permanent magnet ring corresponding to the first electromagnetic ring is installed at the top of the inverted conical slide block.

[0012] In a new embodiment, a second electromagnetic ring is installed on the top of the suspended outer cylinder, and a second permanent magnet ring corresponding to the second electromagnetic ring is installed on the top of the sealing top column.

[0013] In a new embodiment, an insulating outer ring is provided on the outside of the connection between the main speed exhaust cylinder and the heat slow exhaust cylinder.

[0014] In a new embodiment, the air box is also equipped with an altitude detection component for detecting the external ambient air pressure. The altitude detection component includes an altitude pressure detector and a controller. The altitude pressure detector is installed on the top of the air box and is signal-connected to the controller. There are two controllers, which are respectively installed on the outer wall of the main speed exhaust cylinder and the outer wall of the heat insulation outer ring. The controllers are electrically connected to the built-in power supplies of the first electromagnetic ring and the second electromagnetic ring respectively through embedded wires.

[0015] In a new embodiment, the dustproof assembly includes: a protective cover installed at the top of the main exhaust cylinder; two dustproof grilles installed at the side wall outlet of the protective cover; and a guide horn installed on the top wall of the protective cover for guiding the exhaust of high-pressure airflow.

[0016] Beneficial effects: Compared with the prior art, the advantages of the present invention are as follows: 1. By setting up a main pressure relief channel and a branch slow heat relief channel, and making them respond to instantaneous high pressure impact and continuous thermal pressure respectively, this application solves the problem that traditional pressure relief devices are difficult to distinguish fault types and cannot effectively deal with slow pressure rise. This solution can not only effectively prevent the gas box from deforming and being damaged due to instantaneous arc overpressure, but also eliminate the safety hazard of pressure accumulation due to abnormal slow temperature rise that cannot be released in time, thus achieving comprehensive and precise protection of the ring main unit gas box.

[0017] 2. When an arcing failure occurs inside the gas box, the resulting high-speed, high-pressure airflow can directly push the inverted cone slide block in the main pressure relief assembly to move upward, quickly opening the main pressure relief channel. During this process, the linkage shielding ring moves synchronously to cut off the path to the slow-heating pressure relief channel, ensuring that all high-pressure gas is concentrated and discharged at high speed from the main channel. This design achieves rapid pressure relief response, greatly reducing the risk of structural damage to the gas box due to instantaneous overpressure.

[0018] 3. For continuous pressure rise caused by abnormal temperature increase of the insulating medium, the thermal drive mechanism senses and acts. When the heated metal sheet senses the abnormal temperature and expands, it will release the mechanical lock on the sealing top column, allowing the accumulated pressure to push open the sealing top column and form a small-diameter branch pressure relief channel for slow exhaust. By using the dual mechanism of thermal triggering and pressure drive, it ensures that the airtightness and insulation strength of the equipment are maintained to the maximum extent while releasing pressure.

[0019] 4. The ambient air pressure changes are monitored in real time by an altitude pressure detector and controller. When in a high-altitude, low-pressure environment, the controller drives the first electromagnetic ring to generate a magnetic field that repels the first permanent magnet ring, providing an additional downward electromagnetic repulsion force for the inverted conical slide block. This repulsion force, combined with the elastic force of the reset spring, constitutes a higher synthetic start-up threshold, thereby offsetting the tendency of false operation caused by the increase in pressure difference between the inside and outside of the cabinet, and ensuring that the main pressure relief channel will only be opened under real instantaneous high-pressure faults.

[0020] 5. Also based on the ambient air pressure signal, the controller synchronously drives the second electromagnetic ring to apply a downward magnetic repulsion force to the sealing top column, increasing the pressure threshold required for its opening. This means that the opening of the slow-heat exhaust channel must simultaneously meet the requirements of the thermally sensitive drive mechanism being unlocked by heat and the slow-heat pressure in the air box being large enough to overcome the enhanced sealing force. This ensures that in high-altitude environments, the device will not malfunction due to a simple pressure difference or slight temperature rise, and will only start accurately when a real fault occurs. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0022] Figure 2 This is a three-dimensional structural schematic diagram of the present invention from another perspective.

[0023] Figure 3 This is a schematic diagram of the disassembled structure of the pressure relief pipe and the connecting sleeve of the present invention.

[0024] Figure 4 This is a schematic diagram showing the connection state between the main speed discharge cylinder and the heat slow discharge cylinder of the present invention.

[0025] Figure 5 This is a schematic diagram of the internal structure of the main speed extruder of the present invention.

[0026] Figure 6 This is a schematic diagram showing the connection state between the inverted conical slide block and the shielding ring of the present invention.

[0027] Figure 7 This is a schematic diagram of the internal structure of the heat-relieving cylinder of the present invention.

[0028] Figure 8 This is a schematic diagram of the internal structure of the suspended outer cylinder of the present invention.

[0029] Figure 9 For the present invention Figure 8 Enlarged view of the structure at point A.

[0030] Figure 10 For the present invention Figure 8 Enlarged view of the structure at point B.

[0031] Figure 11 This is a schematic diagram of the dustproof component structure of the present invention.

[0032] The attached diagram is labeled as follows: 1. Cabinet; 2. Air box; 3. Pressure relief pipe;

[0033] 4. Pressure relief control assembly; 41. Main speed exhaust cylinder; 411. Thermal insulation outer ring; 42. Connecting sleeve; 43. Heat-relieving exhaust cylinder;

[0034] 5. Dustproof components; 51. Protective cover; 52. Dustproof grille; 53. Guide horn;

[0035] 6. Main pressure relief assembly; 61. Cross base; 611. First electromagnetic ring; 62. Central column; 63. Inverted conical slide block; 631. First permanent magnet ring; 64. Return spring; 65. Shielding ring;

[0036] 7. Auxiliary leakage assembly; 71. Suspension outer cylinder; 711. Second electromagnetic ring; 72. Sealing top column; 721. Locking groove; 722. Weak spring; 723. Second permanent magnet ring; 73. Valve seat ring; 74. Heat flow pipe; 75. Thermosensitive drive mechanism; 751. Heated metal sheet; 752. Locking column;

[0037] 8. Altitude detection component; 81. Altitude pressure detector; 82. Controller. Detailed Implementation

[0038] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0039] This application provides an adaptive protection device for ring main units, which solves the problems of existing fixed threshold rupture discs failing to adequately release slowly rising pressure inside the unit and being prone to malfunction due to pressure differences in high-altitude environments. In use, it utilizes a main pressure relief channel and branch slow-heat pressure relief channels, making them respond to instantaneous high-pressure impacts and continuous thermal pressures respectively. This effectively prevents the gas box from deforming and being damaged due to instantaneous arc overpressure, and also eliminates the safety hazard of pressure accumulation due to abnormally slow heating that cannot be released in time, thus achieving adaptive protection for the ring main unit gas box.

[0040] The technical solutions in this application are intended to solve the above-mentioned technical problems, and the overall approach is as follows.

[0041] Example 1, please refer to Figures 1-11 This application provides an adaptive protection device for a ring main unit, including a cabinet 1, a gas box 2 installed on the back of the cabinet 1 and filled with environmentally friendly insulating gas, and a pressure relief pipe 3 connected at one end to the top of the gas box 2 for pressure relief of the gas box 2; a pressure relief control component 4 is installed on the top of the gas box 2, and a dustproof component 5 is installed on the top of the pressure relief control component 4; the pressure relief control component 4 includes a funnel-shaped main speed discharge cylinder 41 placed on the top of the gas box 2, a connecting sleeve 42 sealingly connecting the main speed discharge cylinder 41 and the pressure relief pipe 3, and a heat-relieving discharge cylinder 43 symmetrically installed on both sides of the main speed discharge cylinder 41 and connected to its funnel slope; the main speed discharge cylinder 41 and the heat-relieving discharge cylinder 43 correspond to two protection states: when a momentary high pressure is generated in the gas box 2 due to an arcing fault, the main speed discharge cylinder 41 responds to the high pressure impact and quickly opens the main pressure relief channel; when a continuous hot pressure is generated in the gas box 2 due to an abnormally slow temperature rise, the heat-relieving discharge cylinder 43 responds to the combined effect of heat and pressure and triggers the opening of the branch pressure relief channel.

[0042] In a preferred embodiment of this solution, this application provides an improved pressure relief structure for the gas box 2 of an environmentally friendly gas-insulated ring main unit. This structure can accurately distinguish and respond to three types of pressure scenarios: instantaneous electric arc high voltage, slow thermal pressure rise, and malfunction due to low air pressure at high altitude. By adaptively switching the pressure relief channel and adjusting the action threshold, it effectively prevents deformation of the gas box 2 while eliminating the safety hazard of failure to release pressure due to slow pressure rise without reaching the threshold, significantly improving the reliability of the equipment under different operating conditions.

[0043] Specifically, the operating scenarios for the adaptive protection device of this ring main unit are as follows:

[0044] First, when a momentary high-voltage impact occurs inside the ring main unit's gas box 2 due to a fault arc, a high-speed, high-flow-rate impact airflow is discharged from the pressure relief pipe 3 connected to the gas box 2, and enters the lower section of the main speed exhaust cylinder 41 through the docking sleeve 42 connected to the pressure relief pipe 3. This directly acts on the bottom pressure-bearing surface of the inverted conical slide block 63. When this impact pressure overcomes the preload force (i.e., the set threshold) of its top return spring 64, it pushes the inverted conical slide block 63 to slide upwards along the central column 62. The inverted conical slide block 63, through its two lower insulating connecting rods, synchronously drives the shielding ring 65 to move upwards. 5 is in a sealed sliding fit with the inner wall of the lower tubular section of the main speed exhaust cylinder 41. The direct effect of its upward movement is to close the transverse connection between the main speed exhaust cylinder 41 and the hot slow exhaust cylinder 43, thereby completely blocking the possibility of gas entering the hot slow exhaust channel under high pressure. Subsequently, the inverted cone slide block 63 continues to move upward, and its own inverted cone side and insulating cone sleeve gradually separate from the sealing area of ​​the lower section of the main speed exhaust cylinder 41, thereby opening an annular channel. At this time, the main pressure relief channel is fully opened, and the high-pressure gas rushes out at high speed. It passes through the protective cover 51 at the top for initial blocking, the guide horn mouth 53 for diversion and diffusion, and is quickly discharged into the atmosphere through the windproof and dustproof grille 52. This process achieves rapid pressure relief and can effectively prevent the gas box 2 from plastic deformation or structural damage due to instantaneous overpressure.

[0045] It is important to note that under instantaneous high-pressure impact, the upward thrust of the airflow on the inverted conical slide block 63 will be instantly met by the initial preload reaction force from the return spring 64 (or, in another case, the limited and highly stiff compression stroke of the return spring 64 itself). This determines that the inverted conical slide block 63 is neither easily pushed by ordinary airflow nor pushed far away. These two forces will quickly reach a dynamic equilibrium. At this time, the inverted conical slide block 63 will stabilize at a limited opening height, forming a sufficiently large annular pressure relief channel, allowing the high-pressure gas to be ejected at high speed. Based on this limited opening height, the rising distance of the shielding ring 65 connected to the inverted conical slide block 63 will completely cover and seal the connection port of the heat-relieving exhaust cylinder 43 throughout the depressurization process of the main speed exhaust cylinder 41. Therefore, the problem of the shielding ring 65 failing to seal the connection port of the heat-relieving exhaust cylinder 43 will not occur due to the unlimited rising of the inverted conical slide block 63 driving the shielding ring 65 to rise.

[0046] Second, when the insulation medium inside the cabinet experiences abnormal heating due to aging, malfunction, or seal failure of electrical components, resulting in a slow rise in gas pressure, the generated slowly heated gas enters the main speed exhaust cylinder 41 via the gas box 2, pressure relief pipe 3, and connecting sleeve 42. Since this pressure is insufficient to push the inverted conical slide block 63 upward, the gas instead enters the thermal slow exhaust cylinder 43, which is connected to the main speed exhaust cylinder 41. The gas entering the thermal slow exhaust cylinder 43 first contacts the inclined guide ring surface of the valve seat ring 73. This inclined surface helps to gather and guide the gas, allowing it to better enter the thermal flow pipes 74 on both sides of the valve seat ring 73. In the process, the slowly heated gas entering the heat flow pipe 74 rises continuously to its upper part and comes into contact with the heated metal sheet 751 at the upper part of the heat flow pipe 74. After absorbing the abnormal heat from the cabinet, it produces significant thermal expansion deformation. This deformation directly drives the locking column 752 linked to it to move to the outside of the pipe, so that its front end exits from the locking groove 721 of the sealing top column 72, thereby releasing the mechanical locking of the sealing top column 72.

[0047] At this time, the continuous slow-heating pressure in the gas box 2 acts on the bottom of the sealing top column 72, pushing it to overcome the slight downward resistance provided by the weak spring 722 and slide upward along the central through hole of the valve seat ring 73. The upward movement of the sealing top column 72 causes an annular gap to be formed between its side wall and the valve seat ring 73. This is the small-diameter branch pressure relief channel. The slow-heating gas can be discharged slowly, stably and controllably through this gap. This can effectively release the accumulated pressure to prevent the gas box 2 from slowly deforming, and the limited opening can maintain the overall airtightness of the equipment to the maximum extent, avoiding a sudden drop in insulation strength.

[0048] Third, in high-altitude areas, the external atmospheric pressure drops significantly. This pressure difference can easily cause the aforementioned pressure relief devices, which rely on pressure difference for operation, to malfunction. The following are solutions to this problem:

[0049] Threshold adjustment of the main pressure relief channel (pressure relief of the main speed exhaust cylinder 41): The ambient air pressure is detected in real time by the altitude pressure detector 81 and the signal is transmitted to the controller 82. The controller 82 then activates the first electromagnetic ring 611 installed on the cross base 61 at the bottom of the main speed exhaust cylinder 41. By adjusting the input current, the first electromagnetic ring 611 generates a magnetic field with the same polarity as the first permanent magnet ring 631 installed on the top of the inverted cone slide block 63, generating an additional downward electromagnetic repulsion force. This electromagnetic repulsion force is linearly superimposed with the elastic force of the return spring 64, together forming a higher synthetic start threshold. This setting effectively raises the action threshold of the main pressure relief channel, offsetting the tendency of false activation caused by the increased pressure difference between the inside and outside at high altitudes, and ensuring that the inverted cone slide block 63 can only be pushed to open the main pressure relief channel when a real arc fault occurs and the instantaneous high pressure is sufficient to break through the synthetic threshold.

[0050] Dual-condition locking of the slow-heat exhaust channel (pressure relief of the slow-heat exhaust cylinder 43): The controller 82 synchronously activates the second electromagnetic ring 711 suspended at the top of the outer cylinder 71 inside the slow-heat exhaust cylinder 43. Similarly, through current adjustment, it generates a magnetic field that repels the second permanent magnet ring 723 at the top of the sealing top column 72. This magnetic field with the same poles repelling each other generates a continuous downward magnetic repulsion force. This force acts directly on the sealing top column 72, giving it an additional downward pre-tightening force. This actively drives the sealing top column 72 to descend, and the rod of the sealing top column 72 enters more of the lower area of ​​the valve seat ring 73. This causes the slow-heat pressure in the air box 2 to accumulate to a higher threshold in order to overcome this enhanced sealing force and push the top column upward. Its direct effect is to significantly increase the opening pressure setting value of the pressure relief channel, thereby ensuring that the device will not be falsely opened due to the increased internal and external pressure difference in high-altitude and low-pressure environments.

[0051] Under this setting, the opening of the sealing top column 72 requires two conditions to be met simultaneously:

[0052] First, the heated metal sheet 751 inside the heat flow pipe 74 must expand due to heat, driving the locking column 752 to move outward and releasing the mechanical lock on the sealing top column 72. This is the premise and basis of the action, ensuring that heat is the core criterion for triggering the slow discharge.

[0053] Second, the slow-heating pressure inside the air box 2 must be large enough to overcome the combined force threshold formed by the magnetic repulsion of the second electromagnetic ring 711 and the tension of the weak spring 722.

[0054] In response to the above two points, this dual condition locking of thermal unlocking and pressure breakthrough fundamentally ensures that in high-altitude environments, the slow-heat exhaust channel will not be mistakenly opened due to a simple increase in the pressure difference between the inside and outside of the cabinet, nor will it activate due to only a slight increase in temperature. It will only be accurately activated in real fault scenarios where there is indeed an abnormal temperature rise accompanied by an excessive slow-heat pressure, thus achieving accurate fault diagnosis and high reliability.

[0055] Please see Figures 4-6The main speed exhaust cylinder 41 is equipped with a main pressure relief assembly 6, which includes a cross base 61, a central column 62, and an inverted conical slide block 63. The cross base 61 is fixedly installed inside the upper side of the main speed exhaust cylinder 41, and a central column 62 of the same length as the main speed exhaust cylinder 41 is vertically installed at its bottom. The inverted conical slide block 63 slides on the central column 62, and the top of the inverted conical slide block 63 is connected to the bottom of the cross base 61 through a return spring 64. Block 63 forms a sealed sliding fit with the inner wall of the lower tubular section of the main speed discharge cylinder 41, and an insulating cone sleeve is fitted on the outside of the inverted cone slide block 63; the lower part of the inverted cone slide block 63 is connected to a shielding ring 65 through two insulating connecting rods, and the shielding ring 65 forms a sealed sliding fit with the inner wall of the lower tubular section of the main speed discharge cylinder 41. When the inverted cone slide block 63 is impacted by high pressure and moves upward, the shielding ring 65 moves upward and shields the communication port between the heat-relieving discharge cylinder 43 and the main speed discharge cylinder 41.

[0056] In the preferred embodiment of this solution, by setting up a cross base 61, a central column 62, and an inverted conical slide block 63, and utilizing the sealed sliding fit between the inverted conical slide block 63 and the lower tubular section of the main speed discharge cylinder 41, the air box 2 under normal conditions is ensured, and it can quickly overcome the resistance of the return spring 64 and move upward during instantaneous high pressure impact. The return spring 64, with its strong preload and limited working stroke, actively limits the rising distance of the inverted conical slide block 63 to a limited and defined range, and then quickly opens the main pressure relief channel to achieve the rapid discharge of high pressure gas, effectively preventing the air box 2 from deforming due to instantaneous overpressure.

[0057] Meanwhile, the cross base 61 and the central column 62 form a stable support frame, providing precise sliding guidance for the inverted conical slide block 63, preventing it from shifting or jamming under high pressure impact, and ensuring the reliability of the operation; the return spring 64 can drive the inverted conical slide block 63 to automatically reset after the pressure is released, ensuring the reusability of the device;

[0058] Secondly, by using the inverted conical slide block 63 and the shielding ring 65, the connection between the main speed discharge cylinder 41 and the hot slow discharge cylinder 43 is simultaneously sealed during high-pressure impact, which can completely block the high-pressure gas from entering the hot slow discharge channel, ensuring that all high-pressure gas flow is concentrated and discharged from the main pressure relief channel, avoiding the decrease in pressure relief efficiency caused by diversion, and ensuring the maximum pressure relief effect. In addition, the insulating conical sleeve outside the inverted conical slide block 63 and the insulating connecting rod connecting the shielding ring 65 can effectively block electrical conduction, preventing the electric arc or charge generated during the high-pressure gas discharge process from damaging the pressure relief structure.

[0059] Please see Figure 7 and Figure 8The heat-relieving cylinder 43 is equipped with an auxiliary leakage assembly 7, which includes a suspension outer cylinder 71, a sealing top column 72, and a valve seat ring 73. The suspension outer cylinder 71 is installed on the upper side inside the heat-relieving cylinder 43. The valve seat ring 73 is installed on the lower side inside the heat-relieving cylinder 43, and the bottom of the valve seat ring 73 is set with an inclined annular surface. The sealing top column 72 slides inside the suspension outer cylinder 71. Locking grooves 721 are opened on both sides of the sealing top column 72. The top of the sealing top column 72 is also connected to the upper protruding ring of the inner wall of the suspension outer cylinder 71 through a weak spring 722. The lower rod of the sealing top column 72 slides and seals with the through hole in the middle of the valve seat ring 73, and is used to seal the through hole. Heat flow pipes 74 are installed on both sides of the middle of the valve seat ring 73. A heat-sensitive drive mechanism 75 is installed inside the heat flow pipe 74. The heat-sensitive drive mechanism 75 is activated when heated to release the locking of the sealing top column 72.

[0060] In the preferred embodiment of this solution, by setting up a suspended outer cylinder 71, a sealing top column 72 and a valve seat ring 73, the sliding sealing cooperation between the sealing top column 72 and the valve seat ring 73, combined with the slight resistance of the weak spring 722, ensures that the air box 2 is sealed under normal conditions. Only when the air pressure slowly accumulates, the small-diameter channel is gradually opened to achieve stable exhaust and avoid excessive damage to the airtightness caused by rapid pressure relief.

[0061] Meanwhile, the suspended outer cylinder 71 provides guidance for the sealing top column 72 to avoid deviation and jamming, the weak spring 722 ensures automatic reset after the fault is cleared, ensuring reusability, and the inclined annular surface of the valve seat ring 73 guides gas into the hot flow pipe 74, improving the temperature response efficiency of the thermal drive mechanism 75.

[0062] Further, please refer to Figure 8 and Figure 9 The thermal drive mechanism 75 includes a heated metal sheet 751 and a locking pin 752. The heated metal sheet 751 is installed on the upper part of the outer wall of the heat flow pipe 74 and expands and deforms in the direction of the outer side of the heat flow pipe 74 when heated. One end of the locking pin 752 is connected to the heated metal sheet 751 and moves with its deformation, while the other end passes through and slides on the upper part of the inner wall of the heat flow pipe 74. The locking pin 752 is adapted to the locking groove 721 located on the sealing top pin 72.

[0063] In a preferred embodiment of this solution, at room temperature, the inner end of the locking pin 752 is engaged in the locking groove 721, locking the sealing pin 72 in the closed position; when the heated metal sheet 751 expands due to the increase in temperature, it drives the locking pin 752 to move outward, causing it to exit from the locking groove 721 and releasing the locking of the sealing pin 72.

[0064] Meanwhile, the heated metal sheet 751 is installed on the upper part of the outer wall of the heat flow pipe 74, which can directly contact the abnormally heated gas guided by the inclined surface of the valve seat ring 73, greatly shortening the heat conduction path. Combined with the inherent rapid thermal response characteristics of the metal material, it can quickly generate significant expansion in the early stage of abnormal temperature, driving the locking column 752 to move outward and exit the locking groove 721, and timely releasing the locking of the sealing top column 72, thus gaining valuable time for subsequent pressure relief.

[0065] It should be noted that by selecting heat-sensitive metal sheets 751 of different materials or thicknesses, the trigger temperature threshold of their expansion driving force can be precisely set, thereby flexibly adapting to the specific temperature safety range of the insulation chamber of different models of ring main units, effectively avoiding protection lag or malfunction caused by sensing deviation.

[0066] Finally, when the fault inside the cabinet is cleared and the temperature drops, the heated metal sheet 751 automatically cools and shrinks, causing the locking pin 752 to reset inward and re-embed into the locking groove 721. This ensures that the device can quickly restore its initial sealing state after a single pressure relief action, meeting the key requirement of reusable and maintenance-free protection equipment in the long-term operation of the ring main unit, and effectively overcoming the drawback of frequent replacement of disposable pressure relief components.

[0067] Please see Figures 4-6 An insulating outer ring 411 is provided on the outside of the connection between the main speed discharge cylinder 41 and the heat slow discharge cylinder 43.

[0068] By setting up an insulating outer ring 411, during summer outdoor exposure, the insulating outer ring 411 can isolate the high temperature conduction outside the cabinet 1, preventing abnormal rise in the temperature of the heat-relieving cylinder 43 wall, which would cause the thermally sensitive drive mechanism 75 to misjudge the temperature rise inside the gas box 2 and trigger unlocking. In winter low temperature or high altitude cold environment, its insulating properties can prevent the heat inside the heat-relieving cylinder 43 from being rapidly absorbed by the external low temperature, preventing the slow temperature rise that has already occurred inside the gas box 2 from being offset, which would cause the thermally sensitive drive mechanism 75 to leak before reaching the expansion threshold. By maintaining the independence of the internal temperature environment of the heat-relieving cylinder 43, it is ensured that the thermally sensitive drive mechanism 75 only responds to the real fault temperature rise inside the gas box 2, and is not misled by external temperature changes, thus ensuring the accuracy of the dual triggering logic of temperature and pressure.

[0069] Please see Figure 5 A first electromagnetic ring 611 is installed at the bottom of the cross base 61, and a first permanent magnet ring 631 corresponding to the first electromagnetic ring 611 is installed at the top of the inverted conical slide block 63.

[0070] Further, please refer to Figure 10 A second electromagnetic ring 711 is installed on the top of the suspended outer cylinder 71, and a second permanent magnet ring 723 corresponding to the second electromagnetic ring 711 is installed on the top of the sealing top column 72.

[0071] Furthermore, please refer to Figure 2 and Figure 3 The air box 2 is also equipped with an altitude detection component 8 for detecting the external air pressure. The altitude detection component 8 includes an altitude pressure detector 81 and a controller 82. The altitude pressure detector 81 is installed on the top of the air box 2 and is connected to the controller 82 by signal. There are two controllers 82, which are respectively installed on the outer wall of the main speed exhaust cylinder 41 and the heat insulation outer ring 411. The controllers 82 are electrically connected to the built-in power supply of the first electromagnetic ring 611 and the second electromagnetic ring 711 through embedded wires.

[0072] In the preferred embodiment of this scheme, two controllers 82 are respectively associated with the first electromagnetic ring 611 of the main speed exhaust cylinder 41 and the second electromagnetic ring 711 of the heat insulation outer ring 411 to realize independent adjustment of the main and auxiliary pressure relief channels. Secondly, the altitude pressure detector 81 collects the ambient air pressure in real time, and the controller 82 automatically adjusts the required magnetic repulsion force according to the air pressure data. The first electromagnetic ring 611 and the second electromagnetic ring 711 output the corresponding magnetic field. At high altitude and low air pressure, the magnetic repulsion force increases, which, combined with the spring force, raises the threshold and offsets the risk of malfunction caused by the internal and external pressure difference. At low altitude and normal air pressure, the magnetic repulsion force decreases or returns to zero, without affecting the handling of instantaneous high pressure and slow thermal pressure under the normal pressure of the pressure relief structure.

[0073] Please see Figure 11 The dustproof component 5 includes: a protective cover 51, installed at the top of the main speed exhaust cylinder 41; two dustproof grilles 52, installed at the side wall outlet of the protective cover 51; and a guide horn 53, installed on the top wall of the protective cover 51, for guiding the exhaust of high-pressure airflow.

[0074] In the preferred embodiment of this solution, by setting up a protective cover 51, a dustproof grille 52, and a guide horn 53, the protective cover 51 covers the top of the main speed discharge cylinder 41, which can block large particles of impurities (such as sand, gravel, and fallen leaves) from falling directly into the discharge cylinder; together with the two dustproof grilles 52 at the side wall outlet of the protective cover 51, it can further prevent fine pollutants such as dust and lint in the air from entering; while the guide horn 53, through the annular curved surface, directs the flow of the discharged annular high-pressure airflow, accelerates the gas discharge speed, avoids the formation of vortices in the airflow within the protective cover 51 that would obstruct pressure relief, further improves the pressure relief efficiency under instantaneous high-pressure impact, and helps to prevent deformation of the gas box 2.

[0075] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive protection device for a ring main unit, comprising a cabinet (1), a gas box (2) installed on the back of the cabinet (1) and filled with environmentally friendly insulating gas, and a pressure relief pipe (3) having one end connected to the top of the gas box (2) and used for depressurizing the gas box (2); characterized in that: The top of the air box (2) is equipped with a pressure relief control component (4), and the top of the pressure relief control component (4) is equipped with a dustproof component (5). The pressure relief control assembly (4) includes a funnel-shaped main speed discharge cylinder (41) placed on top of the air box (2), a docking sleeve (42) that seals the main speed discharge cylinder (41) and the pressure relief pipe (3), and a heat-relieving discharge cylinder (43) symmetrically installed on both sides of the main speed discharge cylinder (41) and connected to its funnel slope. The main speed discharge cylinder (41) and the heat-retardant discharge cylinder (43) correspond to two protection states: When a momentary high pressure is generated in the gas box (2) due to an arcing failure, the main speed exhaust cylinder (41) responds to the high pressure impact and quickly opens the main pressure relief channel; When the gas box (2) generates continuous thermal pressure due to abnormally slow temperature rise, the thermal relief cylinder (43) responds to the combined effect of heat and pressure and triggers the opening of the branch pressure relief channel. The main speed discharge cylinder (41) is provided with a main pressure relief assembly (6), which includes a cross base (61), a central column (62), and an inverted conical slide block (63). The cross base (61) is fixedly installed on the upper side inside the main speed discharge cylinder (41), and a central column (62) of the same length as the main speed discharge cylinder (41) is vertically installed at its bottom. An inverted conical slide block (63) slides on the central column (62), and the top of the inverted conical slide block (63) is connected to the bottom of the cross base (61) through a return spring (64). The inverted conical slide block (63) forms a sealed sliding fit with the inner wall of the lower tubular section of the main speed discharge cylinder (41), and an insulating conical sleeve is fitted on the outside of the inverted conical slide block (63); the lower part of the inverted conical slide block (63) is connected to a shielding ring (65) by two insulating connecting rods, and the shielding ring (65) forms a sealed sliding fit with the inner wall of the lower tubular section of the main speed discharge cylinder (41). When the inverted conical slide block (63) is subjected to high pressure impact and moves upward, the shielding ring (65) moves upward and shields the communication port between the heat-relieving discharge cylinder (43) and the main speed discharge cylinder (41); An auxiliary venting assembly (7) is provided inside the heat-relieving cylinder (43). The auxiliary venting assembly (7) includes a suspended outer cylinder (71), a sealing top column (72), and a valve seat ring (73). The suspended outer cylinder (71) is installed on the upper side inside the heat-relieving cylinder (43). The valve seat ring (73) is installed on the lower side inside the heat-relieving cylinder (43), and the bottom of the valve seat ring (73) is set with an inclined annular surface. The sealing top column (72) slides inside the suspended outer cylinder (71), and locking strips are provided on both sides of the sealing top column (72). The top of the sealing top column (72) is connected to the upper protruding ring of the inner wall of the suspension outer cylinder (71) by a weak spring (722), and the lower rod of the sealing top column (72) is slidably sealed with the through hole in the middle of the valve seat ring (73) and used to seal the through hole; a heat flow pipe (74) is installed on both sides of the middle of the valve seat ring (73), and a heat-sensitive drive mechanism (75) is provided in the heat flow pipe (74). The heat-sensitive drive mechanism (75) is activated when heated to release the locking of the sealing top column (72).

2. The adaptive protection device for a ring main unit as described in claim 1, characterized in that, The thermal drive mechanism (75) includes a heated metal sheet (751) and a locking pin (752); The heated metal sheet (751) is installed on the upper part of the outer wall of the heat flow pipe (74), and expands and deforms in the direction of the outer side of the heat flow pipe (74) when heated; One end of the locking pin (752) is connected to the heated metal sheet (751) and moves with its deformation, while the other end passes through and slides on the upper part of the inner wall of the heat flow pipe (74). The locking pin (752) is adapted to the locking groove (721) located on the sealing top pin (72).

3. The adaptive protection device for a ring main unit as described in claim 1, characterized in that, The bottom of the cross base (61) is equipped with a first electromagnetic ring (611), and the top of the inverted conical slide block (63) is equipped with a first permanent magnet ring (631) that corresponds to the first electromagnetic ring (611).

4. The adaptive protection device for a ring main unit as described in claim 1, characterized in that, The top of the suspended outer cylinder (71) is equipped with a second electromagnetic ring (711), and the top of the sealing top column (72) is equipped with a second permanent magnet ring (723) that corresponds to the second electromagnetic ring (711).

5. The adaptive protection device for a ring main unit as described in claim 1, characterized in that, The outer side of the connection between the main speed discharge cylinder (41) and the heat slow discharge cylinder (43) is fitted with a heat insulation outer ring (411).

6. The adaptive protection device for a ring main unit as described in claim 1, characterized in that, The air box (2) is also equipped with an altitude detection component (8) for detecting the external air pressure. The altitude detection component (8) includes an altitude pressure detector (81) and a controller (82). The altitude pressure detector (81) is installed on the top of the air box (2), and the altitude pressure detector (81) is connected to the controller (82) by signal. Two controllers (82) are provided, which are respectively installed on the outer wall of the main speed exhaust cylinder (41) and the heat insulation outer ring (411). The controllers (82) are electrically connected to the built-in power supply of the first electromagnetic ring (611) and the second electromagnetic ring (711) through embedded wires.

7. The adaptive protection device for a ring main unit as described in claim 1, characterized in that, The dustproof component (5) includes: A protective cover (51) is installed on the top of the main speed exhaust cylinder (41); Two dustproof grilles (52) are provided and installed at the side wall outlet of the protective cover (51); The guide horn (53) is installed on the top wall of the protective cover (51) to guide the discharge of high-pressure airflow.

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