Pressure relief valve for power transformer and power transformer

Abstract

The present application provides a pressure relief valve for a power transformer and a power transformer, wherein the pressure relief valve comprises: a through hole is provided on the base, and the first end can be connected to the transformer oil tank; a support device is arranged on the base, and a valve disc seal is arranged on the second end of the base; a top cover is arranged on the side of the support device away from the base; a spring assembly is arranged between the valve disc and the top cover; the first end of the indicator rod is fixed on the valve disc, and the second end thereof can pass through the top cover; a cover is arranged between the base and the top cover, and is used to close the base and the top cover, and the cover can be opened under the action of internal pressure. When the pressure relief valve is opened, the cover can be opened automatically, and the opening of the cover enhances the pressure release capacity, greatly reduces the flow diversion resistance of the cover, greatly reduces the backlog inside the relief valve, improves the safety and working stability of the valve body of the pressure relief valve, and the cover can be closed automatically, and can prevent the invasion of wind, sand, rain and snow, so as to keep the inside of the relief valve clean.

Description

Technical Field

[0001] The invention belongs to the technical field of transformer pressure relief valves, and in particular relates to a quick safety pressure relief valve with an adaptive opening and closing cover for arc faults in a tap changer oil chamber in a power transformer, and a power transformer. Background Art

[0002] When a high-voltage transformer fails during operation, an arc may be generated. The insulating oil is vaporized and cracked by the energy of the arc discharge, producing a large amount of high-temperature oil and gas, which causes a sudden increase in internal pressure and may cause the transformer's mechanical structure to fail. The leakage of high-temperature and high-pressure oil and gas and contact with air will cause fire and explosion hazards. The traditional solution is to set one or more pressure relief valves. When the pressure in the oil chamber increases, the pressure relief valve is opened to discharge the high-temperature and high-pressure oil and gas into the atmosphere, reduce the internal pressure, and prevent combustion and explosion.

[0003] Most of the related research and design of existing pressure relief valves do not consider the impact of the outer cover on the discharge capacity, nor the structural optimization of the outer cover. The existing deflector cover of the pressure relief valve is divided into a guided type or a standard type without a guide, which is used to block the invasion of wind, sand, snow and rain, and prevent birds and insects from flying in. However, no matter what kind of structure of the deflector cover, it will obviously block the flow of the gas-liquid mixture, on the one hand, reducing the discharge capacity of the pressure relief valve, and on the other hand, when the pressure is high, the pressure relief valve will produce a pressure overload, further increasing the pressure on the pressure relief valve, which is very likely to cause safety accidents. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a pressure relief valve for a power transformer and a power transformer, so as to solve or overcome at least one technical problem existing in the prior art.

[0005] In a first aspect, the present application provides a pressure relief valve for a power transformer, comprising:

[0006] A base having a through hole thereon, wherein a first end of the base can be connected to the transformer oil tank;

[0007] A supporting device is arranged on the base,

[0008] a valve disc sealingly disposed on the second end of the base;

[0009] A top cover, which is arranged on a side of the supporting device away from the base;

[0010] a spring assembly disposed between the valve disc and the top cover;

[0011] an indicating rod, a first end of which is fixed to the valve disc and a second end of which is capable of passing through the top cover;

[0012] The cover shell is arranged between the base and the top cover and is used to seal the base and the top cover, and the cover shell can be opened under the action of internal pressure.

[0013] Furthermore, a connecting flange is provided at the first end of the base, and the connecting flange can be sealed and connected to the transformer oil tank.

[0014] Furthermore, a sealing member is provided at the second end of the base, and the valve disc is pressed against the sealing member under the action of the spring assembly;

[0015] The sealing member comprises:

[0016] A rubber ring, which is fitted in the groove formed at the second end of the base;

[0017] A pressure ring is fitted on the rubber ring.

[0018] Furthermore, the supporting device includes a plurality of columns, and the plurality of columns are circumferentially distributed and connected to the base and the top cover.

[0019] Furthermore, two ends of each of the columns are connected to the base and the top cover via screws.

[0020] Furthermore, a plurality of slots are provided on the sides opposite to the base and the top cover for accommodating the columns.

[0021] Furthermore, the valve disc is a disc-shaped structure.

[0022] The outer peripheral wall of the valve disc is fitted on each of the columns and can slide along the axial direction of each of the columns.

[0023] Furthermore, the spring assembly includes a first spring and a second spring, the diameter of the first spring is smaller than that of the second spring, the second spring is coaxially sleeved on the first spring, and both ends of the first spring and the second spring are respectively connected to the valve disc and the top cover.

[0024] Furthermore, the cover shell includes a plurality of protective plates, one side of each of the protective plates is hinged to the top cover, and each of the protective plates is attached to the base by magnetic attraction.

[0025] Furthermore, each of the protective plates is hinged to the top cover via a spring hinge, and a sealing strip is provided on the side of the protective plate facing the valve disc and the top cover.

[0026] Furthermore, the cover shell is polygonal, and a plurality of symmetrical and openable protective plates are provided on the cover shell.

[0027] In a second aspect, a power transformer is provided, using any one of the pressure relief valves for power transformers described above.

[0028] The beneficial effects of this application are:

[0029] The pressure relief valve for power transformer and the power transformer provided in the present application can automatically open the cover when the pressure relief valve is opened. The opening of the cover enhances the pressure release capability and greatly reduces the flow diversion resistance of the cover, thereby greatly reducing the internal backlog of the relief valve and improving the safety and working stability of the pressure relief valve body. In addition, the cover can automatically close to prevent the invasion of wind, sand, rain and snow and keep the inside of the relief valve clean. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0031] Figure 1 is a front view of a pressure relief valve for a power transformer provided according to an embodiment of the present invention;

[0032] Figure 2 is based on Figure 1 Middle AA section view;

[0033] Figure 3 is a top view of a pressure relief valve for a power transformer provided according to an embodiment of the present invention;

[0034] Figure 4 Schematic diagram of the protective plate in the open state according to an embodiment of the present invention.

[0035] Among them, 1-base, 2-protection plate, 3-top cover, 4-signal rod, 5-valve disc, 6-column, 7-first spring, 8-second spring, 9-rubber ring, 10-pressure ring, 11-connecting flange, 12-magnet. DETAILED DESCRIPTION

[0036] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by the same or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0037] refer to Figures 1 to 3The present application provides a pressure relief valve for a power transformer (referred to as relief valve), comprising: a base 1, on which a through hole is opened, and a first end of the base 1 can be connected to a transformer oil tank; a support device, which is arranged on the base 1, and a valve disc 5, which is sealingly arranged on a second end of the base 1; a top cover 3, which is arranged on a side of the support device away from the base 1; a spring assembly, which is arranged between the valve disc 5 and the top cover 3; an indicator rod, a first end of which is fixed on the valve disc 5, and a second end of which can pass through the top cover 3; a cover shell, which is arranged between the base 1 and the top cover 3, and is used to close the base 1 and the top cover 3, and the cover shell can be opened under the action of internal pressure.

[0038] In this embodiment, reference Figure 2 and Figure 3 The first end of the base 1 is provided with a connecting flange 11, and the connecting flange 11 can be sealed and connected with the transformer oil tank. As those skilled in the art should understand, a gasket is provided between the connecting flange 11 and the transformer oil tank to ensure sealing.

[0039] refer to Figure 2 A sealing member is disposed at the second end of the base 1, and the valve disc 5 is pressed against the sealing member under the action of the spring assembly, thereby achieving sealed communication between the release valve and the transformer tank.

[0040] The sealing member includes: a rubber ring 9, which is fitted in the groove opened at the second end of the base 1; and a pressure ring 10, which is fitted on the rubber ring 9. A shoulder structure is provided on the second end of the base 1, and a groove is opened on the shoulder structure. The rubber ring 9 is arranged on the groove of the shoulder structure, or a protrusion is provided on the rubber ring 9, the protrusion is clamped on the groove and adhered to the shoulder structure, so as to ensure that the rubber ring 9 will not be separated from the original position after the valve disc 5 is separated from the base 1, and the sealing of the valve disc 5 and the base 1 is ensured when they contact again. The pressure ring 10 is provided to ensure the stability of the deformation of the rubber ring 9 after extrusion, to avoid irregular deformation or damage to the rubber ring 9, which affects the sealing of the release valve.

[0041] The supporting device includes a plurality of columns 6, and the plurality of columns 6 are circumferentially distributed and connected to the base 1 and the top cover 3. The plurality of columns 6 play a supporting and connecting role, ensuring the structural stability of the release valve.

[0042] The two ends of each of the columns 6 are respectively connected to the base 1 and the top cover 3 by screws. The detachable connection by screw connection is not only conducive to the assembly of the release valve, but also can reduce the manufacturing cost by assembling the various structural parts, and is also convenient for disassembly, which is conducive to later repair and maintenance.

[0043] A plurality of slots are provided on the sides opposite to the base 1 and the top cover 3 to accommodate the columns 6. This facilitates installation and can play a certain limiting role. If a small number of screws fall off, the distance between the valve disc 5 and the base 1 does not change under the action of several of the screws. Both ends of the columns 6 are arranged in the slots, so the supporting function of the columns 6 is not affected.

[0044] The valve disc 5 is a disc-shaped structure, and the outer peripheral wall of the valve disc 5 is attached to each of the pillars 6 and can slide along the axial direction of each of the pillars 6. The arranged pillars 6 play a guiding and limiting role for the valve disc 5. Under the action of the spring assembly and the oil tank pressure, the valve disc 5 can move along the axial direction of the pillars 6, playing a guiding role. In addition, the circumferentially uniform arrangement of the pillars 6 plays a role in limiting the circumferential position of the valve disc 5, avoiding the dislocation problem caused by the valve disc 5 resetting and contacting the base 1 again, thereby avoiding the sealing problem caused by the dislocation.

[0045] The spring assembly includes a first spring 7 and a second spring 8. The diameter of the first spring 7 is smaller than that of the second spring 8. The second spring 8 is coaxially sleeved on the first spring 7. The two ends of the first spring 7 and the second spring 8 are respectively connected to the valve disc 5 and the top cover 3. The purpose of providing two springs is to ensure the stability in the axial direction when the spring is working. The displacement perpendicular to the axial direction of the spring is avoided, and the stability of the movement between the spring assembly and the valve disc 5 is enhanced.

[0046] The cover shell includes a plurality of protective plates 2, one side of each of the protective plates 2 is hinged on the top cover 3, and each of the protective plates 2 is attached to the base 1 by magnetic attraction. Specifically, a magnet 12 is provided to achieve magnetic attraction. As those skilled in the art should understand, the connection method between each protective plate 2 and the base 1 includes but is not limited to magnetic attraction. The protective plate 2 can control the number of openings under the action of pressure as required, and control the opening state under different pressures by controlling the magnetic attraction force or spring tension. The protective plate 2 can also be fixed to the base 1 by screw connection.

[0047] In an optional embodiment, a slide groove (not shown in the figure) can be opened on the base 1, and the protective plate 2 is perpendicular to the length direction of the slide groove. A spring is arranged in the slide groove, and the spring is connected to the protective plate 2. The spring can tighten the protective plate 2 on the base 1.

[0048] Specifically, in an optional embodiment, one side of the protective plate 2 is rotatably connected to the column 6, and the protective plate 2 is tightened by a spring. When the internal pressure is greater than the spring tension, the protective plate 2 rotates around the column 6 to achieve self-opening. When the internal pressure is less than the spring tension, the protective plate 2 rotates back to its original position to achieve automatic closing. It should be understood that each protective plate 2 is sealed and will not be described in detail.

[0049] When the pressure in the transformer tank is too high and needs to be released, the gas pressure is greater than the pressure of the spring assembly, pushing the valve disc 5 open, so that the signal rod 4 extends out of the top cover 3. The extension of the signal rod 4 can be used as an observation signal or touch the signal trigger device to send a signal. When the oil and gas pressure in the release valve is greater than the magnetic attraction or spring tension, each protective plate 2 is pushed open to open the protective plate 2 (refer to Figure 4 ), so that the pressure can be released, when the pressure in the release valve is less than the magnetic attraction force or the spring tension, the protective plate 2 will be reattached to the base 1. It should be understood that when the pressure in the transformer tank is less than the release pressure of the spring assembly, the spring assembly will release energy and press the valve disc 5 against the second end of the base 1.

[0050] In this embodiment, each of the protective plates 2 is hinged to the top cover 3 through a spring hinge, and a sealing strip is provided on the side of the protective plate 2 facing the valve disc 5 and the top cover 3 to prevent the intrusion of wind, sand, rain and snow to keep the inside of the release valve clean. When the protective plate 2 is in the open state, the spring hinge will store energy and can drive the protective plate 2 to close. Specifically, spring hinges with different torsions can be selected according to the actual use environment.

[0051] In the present embodiment, the cover is polygonal, and a plurality of symmetrical protective plates 2 that can be opened are provided on the cover. While enhancing the pressure relief, the stability of the cover is ensured. As those skilled in the art should understand, the cover is made of corrosion-resistant, all-weather-resistant and sufficiently strong stainless steel, or a high-analysis material with three-proof capabilities, so as to have a stronger valve body protection capability. The pressure relief valve for power transformers provided in the present application can automatically open the cover when the pressure relief valve is opened. The opening of the cover increases the relief area, enhances the pressure release capability, greatly reduces the flow diversion resistance of the cover, and greatly reduces the internal backlog of the relief valve, thereby improving the safety and working stability of the valve body of the pressure relief valve, and the cover can automatically close to prevent the invasion of wind, sand, rain and snow to keep the inside of the relief valve clean.

[0052] In a second aspect, a power transformer is provided, which is provided with the pressure relief valve for the power transformer described above.

[0053] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0054] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the scope of protection of the present invention.

Claims

1. A pressure relief valve for a power transformer, characterized in that: include: A base having a through hole thereon, wherein a first end of the base can be connected to the transformer oil tank; A supporting device is arranged on the base, a valve disc sealingly disposed on the second end of the base; A top cover, which is arranged on a side of the supporting device away from the base; a spring assembly disposed between the valve disc and the top cover; an indicating rod, a first end of which is fixed to the valve disc and a second end of which is capable of passing through the top cover; A cover shell is disposed between the base and the top cover, and is used to seal the base and the top cover, and the cover shell can be opened under the action of internal pressure; The supporting device comprises a plurality of columns, and the plurality of columns are circumferentially distributed and connected to the base and the top cover; The housing comprises a plurality of protective plates, one side of each protective plate is hinged to the top cover, and each protective plate is attached to the base by magnetic attraction; Each of the protective plates is hinged to the top cover via a spring hinge, and a sealing strip is provided on the side of the protective plate facing the valve disc and the top cover; The cover shell is polygonal, and is provided with a plurality of symmetrical and openable protective plates.

2. The pressure relief valve for power transformer according to claim 1, characterized in that: A connecting flange is disposed at the first end of the base, and the connecting flange can be in sealing communication with the transformer oil tank.

3. The pressure relief valve for power transformer according to claim 1, characterized in that: A sealing member is disposed at the second end of the base, and the valve disc is pressed against the sealing member under the action of the spring assembly; The sealing member comprises: A rubber ring, which is fitted in the groove formed at the second end of the base; A pressure ring is fitted on the rubber ring.

4. The pressure relief valve for power transformer according to claim 1, characterized in that: Two ends of each of the uprights are connected to the base and the top cover via screws.

5. The pressure relief valve for power transformer according to claim 1 or 4, characterized in that: A plurality of slots are arranged on the opposite sides of the base and the top cover for accommodating the columns.

6. The pressure relief valve for power transformer according to claim 1, characterized in that: The valve disc is a disc-shaped structure. The outer peripheral wall of the valve disc is fitted on each of the columns and can slide along the axial direction of each of the columns.

7. The pressure relief valve for power transformer according to claim 1, characterized in that: The spring assembly includes a first spring and a second spring. The diameter of the first spring is smaller than that of the second spring. The second spring is coaxially sleeved on the first spring. Both ends of the first spring and the second spring are connected to the valve disc and the top cover respectively.

8. A power transformer, characterized in that: The invention relates to a pressure relief valve for a power transformer according to any one of claims 1 to 7.

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