Explosion-proof pressure relief valve for transformer

Abstract

The application provides an explosion-proof pressure release valve for a transformer. The inner pressure release valve cooperates with the outer pressure release valve, so that the device can simultaneously adapt to the pressure release requirements of low-energy and high-energy accidents in the oil tank. When a low-energy accident occurs, the device can release air and indicate the story. When a high-energy arc discharge fault occurs, the rapid explosion of the explosion membrane can effectively release the high-speed shock wave generated by the accident, and simultaneously perform sound and light alarm for dangerous accidents. The oil-gas mixture generated by the transformer fault is a combustible material and has a certain pollution to air. The cavity formed between the inner oil pipe and the outer oil pipe can guide the oil mixture to the exhaust pipe, so that the oil mixture can be concentratedly treated through the exhaust pipe, thereby preventing pollution to air and preventing fire and explosion hazards.

Description

Technical Field

[0001] This invention relates to the field of pressure relief valve technology, specifically to an explosion-proof pressure relief valve for transformers. Background Technology

[0002] Explosion-proof pressure relief valves are mainly used in the oil tanks of oil-immersed power transformers, capacitors, reactors, and other equipment. When the working pressure exceeds the design standard pressure of the built-in pressure relief valve (spring mechanical structure), the pressure is released directly through the internal pressure relief valve.

[0003] The commonly available pressure relief valves on the market mainly consist of components such as a valve seat, diaphragm, top cover, spring, indicator rod, and vent plug. When pressure is generated inside the transformer, the transformer oil exerts pressure on the diaphragm. When the pressure exceeds the spring pressure, the diaphragm begins to move upward. When the pressure reaches a certain value, the spring is compressed, and the transformer oil is discharged. Subsequently, the pressure quickly drops to the normal value, and the diaphragm returns to its original position under the pressure of the spring. The indicator rod of the pressure relief valve does not return to its original position with the diaphragm after popping out.

[0004] At the same time, the pressure relief capacity of the spring-loaded mechanical pressure relief valve is very limited. Its pressure relief capacity is limited by its bottom elastic diaphragm and internal spring, and it cannot meet the pressure relief requirements when a high-energy accident such as a severe arc discharge occurs inside the oil tank.

[0005] To achieve the above objectives, the present invention provides an explosion-proof pressure relief valve for transformers, which can solve the problems mentioned in the background art. Summary of the Invention

[0006] The present invention adopts the following technical solution:

[0007] An explosion-proof pressure relief valve for transformers includes an external pressure relief valve and an internal pressure relief valve. The external pressure relief valve includes an inner oil pipe and an outer oil pipe. The inner oil pipe is located inside the outer oil pipe. One side of the inner oil pipe has an internal oil outlet, and the outer oil pipe has an external oil outlet. The internal and external oil outlets are connected by a flange. A rupture membrane is fixedly installed between the internal and external oil outlets. The surface of the rupture membrane has an opening, which is a narrow, elongated slit with a small flow rate. The inner and external oil pipes of the external pressure relief valve are connected by a fixed flange between the internal and external oil outlets, forming two spaces: an oil guide channel and an inner cavity. When an accident occurs in the oil tank, the oil pressure increases, and the oil and oil vapor come into direct contact with the inner wall of the inner oil pipe through the oil inlet and the oil guide channel, simultaneously releasing pressure from the internal pressure relief valve. At the same time, a small pressure surge is discharged through the opening, and the internal pressure relief valve pushes out a warning sign, serving as a preliminary alarm.

[0008] One side of the inner oil pipe is fixedly connected to the inner pressure relief valve, which is a spring-loaded mechanical pressure relief valve. The principle of this inner pressure relief valve is the spring-triggered mechanical pressure relief valve commonly used in actual production. When the pressure relief diaphragm is compressed by pressure, it can retract the indicator rod to provide an alarm. At the same time, dangerous pressure can be discharged by setting a drain port. The present invention uses a spring-loaded mechanical pressure relief valve without a drain port, which is sufficient to meet the pressure transmission requirements. It works in conjunction with the opening above the rupture diaphragm to relieve pressure.

[0009] Preferably, the outer oil pipe is provided with a mounting plate at its bottom, the oil inlet end of the inner oil pipe is fixedly connected to the mounting plate, a cavity is formed between the inner and outer oil pipes, an exhaust pipe is provided on one side of the outer oil pipe, the cavity connects the exhaust pipe to the external oil outlet, one end of the mounting plate is connected to the oil inlet of the inner oil pipe, and the other end is connected to the oil outlet. This allows the mounting plate to be directly disassembled to disassemble the interior of the inner oil pipe during intermittent replacement of the device, facilitating maintenance and cleaning. At the same time, the formation of the cavity makes the inner and outer oil pipes form independent spaces, which can prevent leakage and backflow of airflow, and can guide the oil-gas mixture to the exhaust pipe for independent centralized collection and treatment, preventing environmental pollution.

[0010] Preferably, a control box is provided on one side of the external oil pipe. The control box contains an audible and visual alarm and a controller. The control box is designed to be easy for users to adjust independently.

[0011] Preferably, the exhaust pipe is equipped with a flow detector. The flow detector is used to detect changes in the flow rate of the oil-gas mixture at the oil outlet. The flow detector is electrically connected to the controller. The flow detector, controller, and audible and visual alarm are matched. When a high-energy electric arc accident occurs, a large shock wave will be generated. If the shock wave exceeds the normal venting flow range, an electrical signal will be transmitted to trigger the audible and visual alarm. This is to warn that a high-energy fault has occurred inside the external pressure relief valve, resulting in a large pressure and complete rupture of the rupture membrane, requiring immediate replacement.

[0012] Preferably, the mounting plate is provided with an oil inlet, one end of which is connected to a flange connecting plate, and the end of the oil inlet away from the flange connecting plate is connected to the inner oil pipe. The oil inlet and outlet are provided to facilitate the guidance of oil. At the same time, the modular connection is more suitable for flange connection and sealing connection, which enhances the airtightness and safety of the pressure relief valve.

[0013] Preferably, the internal pressure relief valve is provided with a spring mechanism, a pressure relief diaphragm, and a marker rod. The bottom of the internal pressure relief valve is provided with a pressure sensing port, the pressure relief diaphragm is installed inside the pressure sensing port, a support ring is provided around the marker rod, the spring mechanism cooperates with the support ring, one end of the marker rod is connected to the pressure relief diaphragm, when the pressure relief diaphragm is compressed, the marker rod gradually moves until the spring mechanism quickly pops out, at which point the marker rod quickly extends upward, which can provide a preliminary warning.

[0014] Preferably, the outer oil pipe is provided with a cover plate on the side away from the flange connection plate, and the cover plate is provided with an plexiglass cap. The transparent plexiglass cap makes it easy to observe the extension status of the marker rod and to observe whether there is an internal malfunction.

[0015] Preferably, one end of the sign rod passes through the internal pressure relief valve and the cover plate, and the end of the sign rod away from the internal pressure relief valve is located inside the plexiglass cap, with a warning label inside the plexiglass cap.

[0016] Preferably, a limiting seat is provided on the periphery of the end of the marker rod away from the internal pressure relief valve. The limiting seat is slidably connected to the inside of the plexiglass cap. The connecting seat can prevent the marker rod from sliding out of the plexiglass cap due to the negative pressure of the oil tank after returning to its original position.

[0017] Preferably, a waterproof plate is provided on one side of the control box, and the waterproof plate is sealed to the control box to improve the safety of the control box.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. By setting an internal pressure relief valve and an external pressure relief valve in cooperation, this invention enables the device to simultaneously adapt to the pressure relief needs of both low-energy and high-energy accidents inside the oil tank. In the event of a low-energy accident, it can provide venting and a warning indication. In the event of a high-energy arc discharge fault, the rapid rupture of the rupture membrane can effectively relieve the high-speed shock wave generated by the accident, while simultaneously providing an audible and visual alarm for dangerous accidents.

[0020] 2. Traditional pressure relief valves leak transformer oil everywhere when guiding oil pressure, and cannot guide the pressure relief oil. This device guides the hydraulic oil discharged from the internal drain port through the external drain port, which can easily send the oil back to the oil tank.

[0021] 3. The oil-gas mixture generated by transformer failure is flammable and pollutes the air. This device can guide the oil mixture to the exhaust pipe through the cavity formed between the inner and outer oil pipes. The oil mixture is centrally treated through the exhaust pipe to prevent air pollution and to prevent the risk of fire and deflagration.

[0022] 4. The present invention installs a flow monitor inside the exhaust pipe to monitor the state of the rupture membrane. When the flow rate exceeds the predetermined value, the rupture membrane ruptures, and an audible and visual alarm is issued. This indicates that a high-energy arc discharge accident has occurred inside the alarm device, warning that the rupture membrane has ruptured. Users can observe the low-energy fault through the warning label, identify whether a high-energy accident has occurred through the audible and visual alarm, and check whether the rupture membrane needs to be replaced. Attached Figure Description

[0023] Figure 1 This is a partial structural installation cross-sectional view of the present invention;

[0024] Figure 2 This is a partial structural cross-sectional view of the present invention;

[0025] Figure 3 This is a bottom view of the structure of the present invention;

[0026] Figure 4 This is a cross-sectional view of the internal pressure relief valve structure of the present invention;

[0027] Figure 5 For the present invention Figure 2 A schematic diagram of the structure at point A.

[0028] In the diagram: 1. External pressure relief valve; 2. Internal pressure relief valve;

[0029] 101. Inner oil pipe; 102. Outer oil pipe; 103. Inner drain port; 104. Outer drain port; 105. Bursting membrane; 106. Opening; 107. Mounting plate; 108. Cavity; 109. Exhaust pipe; 110. Control box; 111. Audible and visual alarm; 112. Controller; 113. Flow detector; 114. Oil inlet; 115. Flange connection plate; 116. Acrylic cap; 117. Warning sign; 118. Waterproof membrane;

[0030] 201. Spring mechanism; 202. Pressure relief diaphragm; 203. Marker pole; 204. Pressure sensing port; 205. Support ring; 206. Cover plate; 207. Limit seat. Detailed Implementation

[0031] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be given below with reference to the accompanying drawings, which illustrate several embodiments of the present invention. However, the present invention can be implemented in different forms and is not limited to the embodiments described in the text. Rather, these embodiments are provided to make the disclosure of the present invention more thorough and complete.

[0032] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly associated with those skilled in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] The present invention will be further described in detail below with reference to the accompanying drawings.

[0035] Please refer to the appendix for one embodiment of the present invention. Figure 1-5 The external pressure relief valve 1 includes an inner oil pipe 101 and an outer oil pipe 102. The inner oil pipe 101 is located inside the outer oil pipe 102. One side of the inner oil pipe 101 is provided with an inner oil outlet 103. The outer oil pipe 102 is provided with an outer oil outlet 104. The inner oil outlet 103 and the outer oil outlet 104 are connected by a flange. A rupture membrane 105 is fixedly provided between the inner oil outlet 103 and the outer oil outlet 104. The surface of the rupture membrane 105 is provided with an opening 106, which is a narrow strip slit with a small flow rate. The inner oil pipe 101 and the outer oil pipe 102 of the external pressure relief valve 1 are connected by a fixed flange between the inner oil outlet and the outer oil outlet, forming two spaces: an oil guide channel and an inner cavity. When an accident occurs in the oil tank, the oil pressure increases, and the oil and oil vapor pass through... The oil inlet 114 and the oil guide channel are in direct contact with the inner wall of the inner oil pipe 101, and at the same time, the pressure is released by the inner pressure relief valve 2. Meanwhile, a small pressure increase accident is discharged through the opening 106. The inner pressure relief valve 2 pushes out the warning sign 117, which plays a preliminary alarm role. One side of the inner oil pipe 101 is fixedly connected to the inner pressure relief valve 2. The inner pressure relief valve 2 is a spring mechanical pressure relief valve. The principle of this inner pressure relief valve 2 is the spring-triggered mechanical pressure relief valve commonly used in actual production. When the pressure relief diaphragm 202 is compressed by pressure, it can pull out the indicator rod to give an alarm. At the same time, dangerous pressure can be discharged by setting a drain port. The invention uses a spring mechanical pressure relief valve without a drain port, which is sufficient to meet the pressure transmission requirements. It works in conjunction with the opening 106 above the rupture diaphragm 105 to release pressure.

[0036] Please refer to this carefully. Figure 1-3The outer oil pipe 102 is provided with a mounting plate 107 at its bottom. The oil inlet end of the inner oil pipe 101 is fixedly connected to the mounting plate 107. A cavity 108 is formed between the inner oil pipe 101 and the outer oil pipe 102. An exhaust pipe 109 is provided on one side of the outer oil pipe 102. The cavity 108 connects the exhaust pipe 109 to the external oil outlet 104. One end of the mounting plate 107 is connected to the oil inlet 114 of the inner oil pipe 101, and the other end is connected to the oil outlet 114. The mounting plate 107 can be directly disassembled to disassemble the interior of the inner oil pipe 101 during intermittent replacement of the device, which is convenient for maintenance and cleaning. At the same time, the formation of the cavity 108 makes the inner oil pipe 101 and the outer oil pipe 102 form an independent space, which can prevent leakage and backflow of air. It can guide the oil-gas mixture to the exhaust pipe 109 for independent centralized collection and treatment, preventing environmental pollution.

[0037] The flow direction and flow method of oil and gas mentioned in this embodiment are as follows: one side of the oil tank is connected to the oil inlet 114 of this device. When a low-energy small deflagration occurs inside the oil tank (such as partial discharge, spark discharge, excessive temperature, etc.), the oil tank pressure rises slowly. When the pressure rises to the pressure relief membrane 202, it pushes the pressure relief membrane 202 to move upward. When the pressure value reaches the opening pressure of the built-in pressure relief valve, the spring mechanism 201 opens quickly. At the same time, the oil and combustible oil-gas mixture can also be discharged from the opening 106. Part of the oil-gas mixture moves through one end of the self-rising box exhaust port, so that the combustible oil-gas mixture can be collected in a concentrated manner through the exhaust port, reducing air pollution. When a high arc accident occurs inside the oil tank, a high-pressure shock wave will be generated. The high pressure enters the spring mechanism 201 of the internal pressure relief valve 2 of this invention from the oil inlet 114. At the same time, the excessive pressure will also over-compress the rupture membrane 105, causing the rupture membrane 105 to rupture instantly and discharge the high-pressure gas and liquid.

[0038] Please refer to another embodiment of the present invention. Figure 1-5The system includes an external pressure relief valve 1 and an internal pressure relief valve 2. The external pressure relief valve 1 includes an inner oil pipe 101 and an outer oil pipe 102. The inner oil pipe 101 is located inside the outer oil pipe 102. One side of the inner oil pipe 101 is provided with an internal oil drain port 103. The outer oil pipe 102 is provided with an external oil drain port 104. The internal oil drain port 103 and the external oil drain port 104 are connected by a flange. A rupture membrane 105 is fixedly provided between the internal oil drain port 103 and the external oil drain port 104. The surface of the rupture membrane 105 is provided with an opening 106. 106 is a narrow strip-shaped gap with a small flow rate. The inner oil pipe 101 and the outer oil pipe 102 of the external pressure relief valve 1 are connected by a fixed flange between the inner oil outlet and the outer oil outlet, forming two spaces: the oil guide channel and the inner cavity. When an accident occurs in the oil tank, the oil pressure increases. The oil and oil vapor come into direct contact with the inner wall of the inner oil pipe 101 through the oil inlet 114 and the oil guide channel, and at the same time, the pressure is released by the internal pressure relief valve 2. Meanwhile, a small pressure increase accident is discharged through the opening 106. The internal pressure relief valve 2 pushes out the warning sign 117, which plays a preliminary alarm role.

[0039] One side of the inner oil pipe 101 is fixedly connected to the inner pressure relief valve 2. The inner pressure relief valve 2 is a spring-loaded mechanical pressure relief valve. The principle of this inner pressure relief valve 2 is the spring-triggered mechanical pressure relief valve commonly used in actual production. When the pressure relief diaphragm 202 is compressed by pressure, it can pull out the indicator rod to provide an alarm. At the same time, dangerous pressure can be discharged by setting a drain port. The spring-loaded mechanical pressure relief valve without a drain port is sufficient to meet the pressure transmission requirements of this invention. It works in conjunction with the opening 106 above the rupture diaphragm 105 to relieve pressure.

[0040] Please refer to this carefully. Figure 2 , Figure 4 , Figure 5 The internal pressure relief valve 2 includes a spring mechanism 201, a pressure relief diaphragm 202, and a marker rod 203. The bottom of the internal pressure relief valve 2 is provided with a pressure sensing port 204. The pressure relief diaphragm 202 is installed inside the pressure sensing port 204. A support ring 205 is provided around the marker rod 203. The spring mechanism 201 cooperates with the support ring 205. One end of the marker rod 203 is connected to the pressure relief diaphragm 202. When the pressure relief diaphragm 202 is compressed, the marker rod 203 gradually moves until the spring mechanism 201 pops out quickly. At this time, the marker rod 203 extends upward quickly, which can provide a preliminary warning.

[0041] The exhaust pipe 109 is equipped with a flow detector 113. The flow detector is used to detect changes in the flow rate of the oil-gas mixture at the oil outlet. The flow detector is electrically connected to the controller 112. The flow detector, controller 112 and audible and visual alarm 111 are matched. When a high-energy electric arc accident occurs, a large shock wave will be generated. If the shock wave is significantly exceeded by the normal venting flow rate, an electrical signal will be transmitted to trigger the audible and visual alarm 111 to sound an alarm. This is to warn that a high-energy fault has occurred inside the external pressure relief valve 1, resulting in a large pressure. The rupture membrane 105 has been completely ruptured and needs to be replaced in time.

[0042] The outer oil pipe 102 is provided with a cover plate 206 away from the flange connection plate 115. The cover plate 206 is provided with an organic glass cap 116. The transparent organic glass cap 116 makes it easy to observe the extension status of the marker rod and to observe whether there is a fault inside.

[0043] One end of the marker rod 203 passes through the internal pressure relief valve 2 and the cover plate 206. The end of the marker rod 203 away from the internal pressure relief valve 2 is located inside the plexiglass cap 116. A warning label 117 is provided inside the plexiglass cap. A limiting seat 207 is provided on the periphery of the end of the marker rod 203 away from the internal pressure relief valve 2. The limiting seat 207 is slidably connected to the inside of the plexiglass cap 116. The connecting seat can prevent the marker rod from sliding out of the plexiglass cap 116 due to the negative pressure of the oil tank after returning to its original position. A waterproof plate 118 is provided on one side of the control box 110. The waterproof plate 118 is sealed to the control box 110 to improve the safety of the control box 110.

[0044] The fault judgment and analysis of the present invention are implemented in the following ways: First, when a low-energy fault occurs inside the pressure relief valve, the spring mechanism 201 is activated, and the indicator rod extends and pushes the warning indicator 117 upward, so that the warning indicator can indicate that a fault has occurred inside. Under the action of the limit seat 207, the indicator rod will not leave the pushing guide range of the plexiglass cap 116. When a large high-energy fault occurs, the spring mechanism 201 extends upward and pushes the warning indicator 117 to the top. At this time, the bursting membrane 105 ruptures instantaneously, causing a large amount of escaped oil vapor to rise to the exhaust port and be concentrated for exhaust. At the same time as it passes through the exhaust port, the flow detector 113 detects a large change in the gas flow rate. When the instantaneous value is greater than the predetermined flow rate value, the flow detector 113 transmits an electrical signal to the control box 110. The control box 110 causes the audible and visual alarm 111 to generate an alarm, which facilitates the identification of danger.

[0045] The present invention has been described by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvement made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, shall be within the protection scope of the present invention.

Claims

1. An explosion-proof pressure relief valve for transformers, characterized in that: The device includes an external pressure relief valve (1) and an internal pressure relief valve (2). The external pressure relief valve (1) includes an inner oil pipe (101) and an outer oil pipe (102). The inner oil pipe (101) is located inside the outer oil pipe (102). An inner drain port (103) is provided on one side of the inner oil pipe (101). An outer drain port (104) is provided inside the outer oil pipe (102). The inner drain port (103) and the outer drain port (104) are connected by a flange. A bursting membrane (105) is fixedly provided between the inner drain port (103) and the outer drain port (104). An opening (106) is provided on the surface of the bursting membrane (105). The opening (106) is a narrow strip slit with a small flow rate. One side of the inner oil pipe (101) is fixedly connected to the inner pressure relief valve (2), which is a spring-loaded mechanical pressure relief valve; The bottom of the outer oil pipe (102) is provided with a mounting plate (107), the oil inlet end of the inner oil pipe (101) is fixedly connected to the mounting plate (107), a cavity (108) is formed between the inner oil pipe (101) and the outer oil pipe (102), an exhaust pipe (109) is provided on one side of the outer oil pipe (102), and the cavity (108) connects the exhaust pipe (109) and the external oil outlet (104). A control box (110) is provided on one side of the external oil pipe (102), and the control box (110) is equipped with an audible and visual alarm (111) and a controller (112). The exhaust pipe (109) is equipped with a flow detector (113), which is used to detect changes in the flow rate of the oil-gas mixture. The flow detector (113) is electrically connected to the controller (112). When a low-energy small deflagration occurs inside the fuel tank, the fuel tank pressure rises slowly. When the pressure rises to the pressure relief membrane (202), it pushes the pressure relief membrane (202) to move upward. When the pressure value reaches the opening pressure of the built-in pressure relief valve, the spring mechanism (201) opens rapidly. At the same time, the mixture of oil and combustible gas can also be discharged from the opening (106). When a high-arc accident occurs inside the fuel tank, a high-pressure shock wave will be generated. The high pressure enters the inner oil pipe (101) from the oil inlet (114). Excessive pressure will also over-compress the rupture membrane (105), causing the rupture membrane (105) to rupture instantly and discharge the high-pressure gas and liquid.

2. The explosion-proof pressure relief valve for transformers according to claim 1, characterized in that: The mounting plate (107) is provided with an oil inlet (114), one end of which is connected to a flange connecting plate (115), and the end of the oil inlet (114) away from the flange connecting plate (115) is connected to the inner oil pipe (101).

3. The explosion-proof pressure relief valve for a transformer according to claim 2, characterized in that: The internal pressure relief valve (2) is provided with a spring mechanism (201), a pressure relief diaphragm (202), and a marker rod (203). The bottom of the internal pressure relief valve (2) is provided with a pressure sensing port (204). The pressure relief diaphragm (202) is installed inside the pressure sensing port (204). The periphery of the marker rod (203) is provided with a support ring (205). The spring mechanism (201) cooperates with the support ring (205). One end of the marker rod (203) is connected to the pressure relief diaphragm (202).

4. The explosion-proof pressure relief valve for a transformer according to claim 3, characterized in that: The outer oil pipe (102) is provided with a cover plate (206) on the side away from the flange connection plate (115), and an plexiglass cap (116) is provided on the cover plate (206).

5. The explosion-proof pressure relief valve for a transformer according to claim 4, characterized in that: One end of the sign bar (203) passes through the internal pressure relief valve (2) and the cover plate (206), and the end of the sign bar (203) away from the internal pressure relief valve (2) is located inside the plexiglass cap (116), and a warning sign (117) is provided inside the plexiglass cap (116).

6. The explosion-proof pressure relief valve for a transformer according to claim 5, characterized in that: The marker rod (203) is provided with a limiting seat (207) on the periphery of the end away from the internal pressure relief valve (2), and the limiting seat (207) is slidably connected to the inside of the plexiglass cap (116).

7. The explosion-proof pressure relief valve for a transformer according to claim 1, characterized in that: A waterproof plate (118) is provided on one side of the control box (110), and the waterproof plate (118) is sealed to the control box (110).

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