An oil-immersed distribution transformer

Abstract

The present disclosure relates to the technical field of transformers, and provides an oil-immersed distribution transformer, which comprises a box body having an inner cavity for accommodating a transformer core and transformer oil; an oil pillow is arranged on the box body, and the oil pillow has a main oil cavity and an emergency oil cavity inside; the inner cavity is in communication with the main oil cavity and the emergency oil cavity; a first flow guide member is arranged in the main oil cavity, and the first flow guide member has a first oil inlet intermediate passage inside; a second flow guide member is arranged in the emergency oil cavity, and the second flow guide member has a second oil inlet intermediate passage inside, the second oil inlet intermediate passage being used for connecting a second branch end and the emergency oil cavity; and a first sliding blocking member is slidingly arranged in the second oil inlet intermediate passage. Through the above technical solution, the technical problem of insufficient safety protection efficiency of the pressure release device of the oil-immersed transformer in the prior art when dealing with sudden explosion accidents is solved.

Description

Technical Field

[0001] The embodiments disclosed herein relate to the field of transformer technology, and more specifically, to an oil-immersed distribution transformer. Background Technology

[0002] As a core component of power transmission and distribution systems, the safe operation of oil-immersed distribution transformers directly impacts the stability and reliability of power supply. During actual operation, partial discharge or arcing faults may occur inside the transformer due to winding short circuits, insulation aging, or oil deterioration. When the fault energy reaches a critical value, the transformer oil rapidly decomposes, producing a large amount of flammable gases (such as hydrogen and methane). These gases mix with air within the sealed oil tank to form an explosive mixture. This explosive mixture can lead to deflagration, which can cause a rapid increase in internal pressure. Currently, most mainstream oil-immersed transformers on the market use mechanical pressure relief valves as safety protection devices. These valves are typically set with an opening pressure of 30-50 kPa according to standard IEC 60076-11, and their structural design is mainly for conventional operating conditions such as transformer overload or slow gas generation. However, they are difficult to effectively handle the instantaneous high voltage (peak values ​​reaching 150-200 kPa) generated by partial deflagration. Therefore, existing pressure relief devices have insufficient safety protection effectiveness in dealing with sudden deflagration accidents, and there is an urgent need to develop a safety device that can respond quickly and release pressure efficiently. Summary of the Invention

[0003] To overcome the above-mentioned defects, embodiments of this disclosure provide an oil-immersed distribution transformer, comprising: The enclosure has an inner cavity for accommodating the transformer core and transformer oil. An oil reservoir is provided on the housing. The oil reservoir has a main oil chamber and an emergency oil chamber inside, and the inner chamber is connected to the main oil chamber and the emergency oil chamber respectively. The second guide member is disposed inside the emergency oil chamber. The second guide member has a second oil inlet intermediate channel inside, which is used to connect the inner cavity and the emergency oil chamber. A first sliding stop is slidably disposed in the second oil inlet intermediate channel. After the first sliding stop is pushed and slid by the oil, the second oil inlet intermediate channel and the emergency oil chamber are connected. An elastic element, one end of which acts on the side wall of the second oil inlet intermediate channel and the other end of which acts on the first sliding stop, is used to make the first sliding stop slide to block the connection between the second oil inlet intermediate channel and the emergency oil chamber.

[0004] For example, at least one embodiment of this disclosure provides an oil-immersed distribution transformer, wherein the inner cavity is connected to the main oil chamber and the emergency oil chamber respectively through a first branch end and a second branch end of the main oil pipe; the inner cavity is connected to the main oil chamber and the emergency oil chamber respectively through a first branch end and a second branch end of the main oil pipe; a second oil inlet intermediate channel is used to connect the second branch end and the emergency oil chamber; the oil-immersed distribution transformer further includes: A first guide member is disposed within the main oil chamber. The first guide member has a first oil inlet intermediate channel inside, which is used to connect the first branch end and the main oil chamber.

[0005] For example, at least one embodiment of this disclosure provides an oil-immersed distribution transformer, which further includes: An oil passage extension pipe is provided inside the emergency oil chamber. The oil passage extension pipe is used to connect the second oil inlet intermediate channel and the emergency oil chamber, and the outlet end of the oil passage extension pipe is higher than the inlet end. A connecting oil pipe is provided, with its two ends inserted into the emergency oil chamber and the first oil inlet intermediate channel, respectively, to allow the oil in the emergency oil chamber to be transported to the main oil chamber through the connecting oil pipe and the first oil inlet intermediate channel.

[0006] For example, at least one embodiment of this disclosure provides an oil-immersed distribution transformer in which the height of the inlet end of the connecting oil pipe in the emergency oil chamber is higher than the height of the outlet end of the oil circuit extension pipe.

[0007] For example, at least one embodiment of this disclosure provides an oil-immersed distribution transformer, wherein the outlet of the first oil inlet intermediate channel is located at the bottom of the main oil chamber, and the oil-immersed distribution transformer further includes: The first flow-damping plate is disposed on the top wall of the first oil inlet intermediate channel; The second flow-damping plate is disposed on the bottom wall of the first oil inlet intermediate channel. The first flow-damping plate and the second flow-damping plate are staggered vertically and laterally, and the sum of the lengths of the first flow-damping plate and the second flow-damping plate is greater than the height of the first oil inlet intermediate channel but less than twice the height of the first oil inlet intermediate channel. A vertically zigzag flow-damping channel is formed between the first flow-damping plate, the second flow-damping plate and the inner wall of the first oil inlet intermediate channel. The inlet and outlet of the first oil inlet intermediate channel are located at the two ends of the flow-damping channel, respectively.

[0008] For example, at least one embodiment of this disclosure provides an oil-immersed distribution transformer, which further includes: The second sliding stop is slidably disposed within the first oil inlet intermediate channel, and after sliding, it blocks or unblocks the flow channel between the first flow buffer plate and the second flow buffer plate. The outlet of the connecting oil pipe is located above the second sliding stop.

[0009] For example, at least one embodiment of this disclosure provides an oil-immersed distribution transformer, which further includes: A pressure valve is installed on the connecting oil pipe and is used to set the connecting pressure of the connecting oil pipe.

[0010] For example, at least one embodiment of this disclosure provides an oil-immersed distribution transformer in which the outer walls of both the main oil chamber and the emergency oil chamber have transparent viewing windows.

[0011] For example, at least one embodiment of this disclosure provides an oil-immersed distribution transformer, which further includes: A pressure relief valve is provided on the housing, with one end extending into the inner cavity, for connecting the inner cavity to the outside when the pressure in the inner cavity increases.

[0012] For example, at least one embodiment of this disclosure provides an oil-immersed distribution transformer, wherein the side wall of the enclosure has a plurality of heat dissipation fins.

[0013] The beneficial effects of the embodiments disclosed herein are as follows: In this disclosure, by setting up a main oil chamber and an emergency oil chamber, and utilizing two branches of the main oil pipe connected to the inner cavity respectively, the main oil chamber plays a conventional pressure regulation role during normal operation. In the event of a sudden increase in oil pressure, the emergency oil chamber is quickly activated, working in conjunction with the main oil chamber to significantly enhance the transformer's ability to cope with sudden pressure changes and prevent damage to the transformer due to excessive pressure. The design of the first sliding stop and elastic element allows the emergency oil chamber to open rapidly when the oil pressure rises, promptly receiving oil flowing into the inner cavity of the transformer, achieving a rapid response to sudden pressure changes, effectively alleviating internal pressure, and ensuring the safe operation of the transformer. The non-backflow design of the emergency oil chamber precisely controls the total amount of oil in the inner cavity. After a sudden pressure change, by reducing the amount of oil in the inner cavity, it effectively prevents violent reactions caused by continued oil expansion, providing a guarantee for the stable operation of the transformer. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments of this disclosure will be briefly introduced below. Obviously, the drawings described below are merely some exemplary embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the content of the exemplary embodiments of this disclosure and these drawings without any creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of an oil-immersed distribution transformer according to one embodiment of the present disclosure; Figure 2 for Figure 1 A schematic diagram of the structure of an oil-immersed distribution transformer in one embodiment; Figure 3 for Figure 1 A schematic diagram of the structure of an oil-immersed distribution transformer in one embodiment; Figure 4 for Figure 3 A partially enlarged structural diagram of section A in the middle; Figure 5 for Figure 3 A magnified schematic diagram of part B in the middle section.

[0016] In the diagram: Box-1, Inner cavity-101, Heat dissipation fins-102, Oil conservator-2, Main oil chamber-201, Emergency oil chamber-202, Transparent viewing window-203, Main oil pipe-3, First branch end-301, Second branch end-302, First guide component-4, First oil inlet intermediate channel-401, Slow flow channel-402, Second guide component-5, Second oil inlet intermediate channel-501, First sliding stop-6, Elastic component-7, Oil circuit extension pipe-8, Connecting oil pipe-9, First slow flow plate-10, Second slow flow plate-11, Second sliding stop-12, Pressure valve-13, Pressure relief valve-14, Gas buffer chamber-15, One-way exhaust valve-16. Detailed Implementation

[0017] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present disclosure and are not intended to limit the scope of the disclosure.

[0018] To keep the drawings concise, each drawing only schematically shows the parts relevant to the disclosure; these do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one," and "several" includes "two" and "more than two."

[0019] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0020] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0021] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure.

[0022] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] like Figures 1-5As shown, this is an oil-immersed distribution transformer according to one embodiment of the present disclosure. The tank 1 serves as the transformer's outer shell, capable of withstanding the pressure under normal internal operating conditions. It can also withstand a certain degree of deformation while maintaining sealing performance under conditions of rapidly increasing internal pressure. The size of the inner cavity 101 is designed according to the transformer's specifications and capacity, providing ample space for the transformer core and sufficient transformer oil. An interface for connecting the main oil pipe 3 is provided on the tank 1, ensuring communication with the main oil chamber 201 and emergency oil chamber 202 of the oil conservator 2. The oil conservator 2 is installed at a suitable position on the top or side of the tank 1, and its structural design aims to meet the transformer's needs for oil regulation and storage under different operating conditions. The main oil chamber 201 and emergency oil chamber 202 are connected to the inner cavity 101 of the tank 1 via a three-way passage. The material of the oil conservator 2 is compatible with that of the tank 1, possessing good sealing and corrosion resistance. During normal operation, the main oil chamber 201 is connected to the inner chamber 101 via the first branch end 301 of the main oil pipe 3, acting as a connector to smoothly adapt to pressure changes caused by variations in oil density. The emergency oil chamber 202 serves as a backup chamber, functioning in emergency situations. The first guide member 4 is placed inside the main oil chamber 201 to ensure smooth flow of transformer oil from the first branch end 301 into the main oil chamber 201. The second guide member 5 is located inside the emergency oil chamber 202, with a similar structure and material to the first guide member 4. The second oil inlet intermediate channel 501 also passes through the second guide member 5, connecting the second branch end 302 to the emergency oil chamber 202. This channel is designed to control the opening and closing of oil flow into the emergency oil chamber 202 to meet emergency needs in sudden situations. The first sliding stop 6 is piston-shaped or plate-shaped, with its dimensions closely matching the inner diameter of the second oil inlet intermediate channel 501, allowing for flexible sliding within the channel while ensuring good sealing to prevent oil leakage. The first sliding stop 6 is made of a lightweight, high-strength, and oil-resistant material, such as polytetrafluoroethylene or aluminum alloy. Its surface is smoothed to reduce friction when sliding within the channel. When the internal oil pressure of the transformer is normal, the first sliding stop 6, under the action of the elastic element 7, blocks the connection between the second oil inlet intermediate channel 501 and the emergency oil chamber 202, keeping the emergency oil chamber 202 in a closed standby state. The elastic element 7 can be compressed when the oil pressure abnormally increases, causing the first sliding stop 6 to slide.

[0024] The specific working process is as follows: During normal operation of the transformer, the transformer oil is kept connected between the inner cavity 101 of the tank 1 and the main oil cavity 201 of the oil conservator 2 through the first branch end 301 of the main oil pipe 3 and the first oil inlet intermediate channel 401 of the first guide member 4. Utilizing the principle of communicating vessels, this smoothly adapts to pressure changes caused by variations in oil density. At this time, the first sliding stop 6, under the action of the elastic member 7, tightly blocks the connection between the second oil inlet intermediate channel 501 and the emergency oil cavity 202, keeping the oil in the emergency oil cavity 202 in a static standby state. When the oil pressure inside the transformer increases rapidly due to partial discharge, arc faults, or other reasons, the increased oil pressure pushes the transformer oil through the second branch end 302 of the main oil pipe 3 into the second oil inlet intermediate channel 501 of the second guide member 5. The oil pressure overcomes the elastic force of the elastic element 7, pushing the first sliding stop 6 to slide within the second oil inlet intermediate channel 501, thus removing the obstruction between the channel and the emergency oil chamber 202. Transformer oil rapidly flows into the emergency oil chamber 202, with both the main oil chamber 201 and the emergency oil chamber 202 serving as oil reserves to alleviate pressure inside the tank 1. After the pressure is rapidly released, the oil pressure decreases, and the elastic force of the elastic element 7 pushes the first sliding stop 6 to slide back to its original position within the second oil inlet intermediate channel 501, re-blocking the connection between the channel and the emergency oil chamber 202. The oil entering the emergency oil chamber 202 no longer flows back into the inner cavity 101, maintaining the reduced total oil volume within the inner cavity 101. This avoids the potentially violent reaction caused by continued oil expansion, and the transformer enters a relatively stable operating state. The emergency oil chamber 202 remains in standby mode.

[0025] In summary, by setting up a main oil chamber 201 and an emergency oil chamber 202, and connecting the two branches of the main oil pipe 3 to the inner cavity 101 respectively, the main oil chamber 201 plays a conventional pressure regulation role during normal operation. In the event of a sudden increase in oil pressure, the emergency oil chamber 202 is quickly activated, working in conjunction with the main oil chamber 201 to significantly enhance the transformer's ability to cope with sudden pressure changes and prevent damage to the transformer due to excessive pressure. The design of the first sliding stop 6 and the elastic element 7 allows the emergency oil chamber 202 to open rapidly when the oil pressure rises, promptly receiving the oil flowing into the inner cavity 101 of the housing 1, achieving a rapid response to sudden pressure changes, effectively alleviating internal pressure, and ensuring the safe operation of the transformer. The non-backflow design of the emergency oil chamber 202 precisely controls the total amount of oil in the inner cavity 101. After a sudden pressure change, by reducing the amount of oil in the inner cavity 101, it effectively prevents violent reactions caused by continued oil expansion, providing a strong guarantee for the stable operation of the transformer.

[0026] In some examples, the oil extension pipe 8 is made of oil-resistant and pressure-resistant metal, such as stainless steel. Its length is customized based on the internal space of the emergency oil chamber 202 and actual needs. The pipe diameter selection must comprehensively consider oil flow rate and flow resistance to ensure smooth oil flow when oil pressure changes. When the internal oil pressure of the transformer increases rapidly, the oil pressure pushes the first sliding stop 6 to slide, removing the obstruction to the second oil inlet intermediate channel 501. At this time, transformer oil flows from the second oil inlet intermediate channel 501 into the inlet end of the oil extension pipe 8. Because the outlet end of the oil extension pipe 8 is higher than the inlet end, the oil will encounter certain resistance when flowing inside the pipe, preventing a sudden large influx of oil into the emergency oil chamber 202. Instead, the oil flows in more gradually, avoiding potential local pressure shocks and oil splashing caused by a sudden large influx of oil into the emergency oil chamber 202. When the pressure is rapidly released, the small amount of oil remaining in the oil extension pipe 8 will not flow back to the second oil inlet intermediate channel 501 under the influence of gravity. Instead, it will remain in the oil extension pipe 8, further ensuring that the oil in the emergency oil chamber 202 does not flow back into the inner cavity 101, maintaining the total amount of oil in the inner cavity 101 after its reduction, and preventing subsequent oil expansion from causing a violent reaction. The design of the outlet end of the oil extension pipe 8 being higher than the inlet end provides a buffer process for the oil to flow into the emergency oil chamber 202. During sudden changes in oil pressure, this avoids a sudden surge of large amounts of oil, allowing the oil to enter the emergency oil chamber 202 smoothly, reducing the impact on the internal structure of the emergency oil chamber 202, protecting the integrity of the emergency oil chamber 202, and also helping to maintain the relative stability of the transformer's internal pressure. The absence of a sudden surge of large amounts of oil not only helps maintain the orderly distribution of oil in the emergency oil chamber 202, but also avoids situations where uneven oil rise could affect the normal operation of internal components or cause localized sealing problems.

[0027] In some examples, the diameter of the connecting oil pipe 9 is determined based on the required oil flow between the emergency oil chamber 202 and the main oil chamber 201, generally between 1 and 5 cm. This ensures smooth oil flow while avoiding excessive diameter that could affect the internal structural layout of the oil conservator 2. One end of the connecting oil pipe 9 is precisely inserted into the emergency oil chamber 202. As the amount of oil in the emergency oil chamber 202 increases, the internal pressure rises continuously. Since the emergency oil chamber 202 has no vent, and the pressure control valve at the vent of the main oil chamber 201 is closed until the pressure in the main oil chamber 201 reaches a threshold, the pressure in the emergency oil chamber 202 is higher than that in the main oil chamber 201. Under the influence of this pressure difference, the oil in the emergency oil chamber 202 is forced into the first inlet intermediate channel 401 through the connecting oil pipe 9, and then flows towards the main oil chamber 201. As the oil is transferred, the pressure in the main oil chamber 201 gradually increases. When it reaches the opening threshold of the outlet pressure control valve, the valve opens, releasing excess gas from the main oil chamber 201 and maintaining its pressure within a certain range. This ensures a continuous pressure difference between the emergency oil chamber 202 and the main oil chamber 201, allowing for continuous oil transfer. When the pressure in the main oil chamber 201 drops to the closing threshold of the outlet pressure control valve, the valve closes. At this point, the oil transferred to the main oil chamber 201 via the connecting oil pipe 9, along with the existing oil in the main oil chamber 201, continues to participate in the pressure regulation process between the main oil chamber 201 and the inner chamber 101. A certain amount of oil is retained in the emergency oil chamber 202 for use in case of the next pressure surge, and the transformer gradually returns to a relatively stable operating state. Utilizing the pressure difference between the emergency oil chamber 202 and the main oil chamber 201, oil is automatically transferred from the emergency oil chamber 202 to the main oil chamber 201 without the need for an additional pumping device, efficiently balancing the oil level and pressure between the two chambers. This automatic adjustment mechanism responds rapidly to sudden changes in transformer pressure, effectively preventing damage to the emergency oil chamber 202 due to excessive pressure and ensuring the safe and stable operation of the transformer under complex conditions. The connecting oil pipe 9 allows for more efficient use of the space in the main oil chamber 201, enabling it to receive excess oil from the emergency oil chamber 202 in emergency situations, avoiding potential oil overflow or pressure inadequacy due to the limited capacity of the emergency oil chamber 202. This optimized utilization of the internal space of the oil conservator improves the overall efficiency of the oil conservator as an oil regulation and storage component.

[0028] In some examples, the design of the inlet end of the connecting oil pipe 9 being higher than the outlet end of the oil extension pipe 8 allows for more precise timing of the oil transfer from the emergency oil chamber 202 to the main oil chamber 201. The transfer to the main oil chamber 201 is only triggered when the oil in the emergency oil chamber 202 has accumulated to a certain level, preventing premature transfer when the oil volume in the emergency oil chamber 202 is low, and ensuring that the emergency oil chamber 202 can effectively buffer pressure in the initial stage. This height difference design helps stabilize the speed at which the oil transfers from the emergency oil chamber 202 to the main oil chamber 201. Because the oil needs to accumulate to a certain height before entering the connecting oil pipe 9, it avoids excessively fast flow rates caused by a sudden influx of large amounts of oil into the connecting oil pipe 9, which could affect the pressure balance and oil distribution within the main oil chamber 201, making the oil transfer process smoother and more orderly. During a sudden pressure change, the oil extension pipe 8 first buffers the oil flowing into the emergency oil chamber 202, and then transfers the oil to the main oil chamber 201 at an appropriate time through the connecting oil pipe 9, forming a step-by-step pressure relief mechanism. This step-by-step buffering method can more effectively cope with the rapidly increasing pressure inside the transformer, avoiding damage to the internal structure of the transformer due to excessive instantaneous pressure changes, and improving the safety of the transformer under pressure change conditions. Reasonable oil transfer control makes the oil distribution in the emergency oil chamber 202 and the main oil chamber 201 more rational. During a pressure change, the emergency oil chamber 202 can gradually transfer oil to the main oil chamber 201 according to the actual pressure situation, avoiding the impact of too much or too little oil in one oil chamber on the pressure regulation effect, and helping to maintain the balance and stability of the internal pressure of the transformer.

[0029] In some examples, both the first and second flow-retardant plates 10 and 11 are made of oil-resistant and corrosion-resistant thin metal sheets, such as stainless steel. Their shapes are designed according to the internal space of the first oil inlet intermediate channel 401, typically rectangular, with dimensions slightly smaller than the cross-sectional dimensions of the first oil inlet intermediate channel 401. After installation, this allows the liquid to flow in an "S"-shaped path. The surfaces of the flow-retardant plates are smoothed to reduce resistance during oil flow. This staggered arrangement aims to increase the flow distance and time of the oil within the channel by altering its flow path, thereby achieving a flow-retardant effect. After entering the flow-retardant channel 402 from the inlet, the oil first impacts the first flow-retardant plate 10, changing its flow direction. Then, it flows downwards along the surface of the first flow-retardant plate 10, changes direction again upon encountering the second flow-retardant plate 11, and finally flows out from the outlet. This zigzag flow path effectively reduces the oil velocity, allowing the oil to enter the main oil chamber 201 more smoothly.

[0030] The zigzag-shaped flow channel 402 formed by the first flow-slowing plate 10 and the second flow-slowing plate 11 effectively extends the flow path of the oil within the first oil inlet intermediate channel 401, significantly reducing the oil flow velocity. This helps prevent excessive impact force from the oil entering the main oil chamber 201 due to excessive flow velocity, preventing damage to components such as windings within the main oil chamber 201 and ensuring the stability of the transformer's internal structure. The flow-slowing channel 402 changes the flow direction of the oil multiple times, preventing the oil from concentrating in one area and improving heat dissipation efficiency. The synergistic effect of the oil entering from the bottom of the first oil inlet intermediate channel 401 and the oil flowing out of the flow-slowing channel 402 helps promote natural convection of the oil within the main oil chamber 201. Under the guidance and buffering of the oil flowing out of the flow-slowing channel 402, the new oil entering from the bottom can more smoothly push the hot oil upwards, allowing the oil to form a good natural convection circulation within the main oil chamber 201, accelerating heat transfer and dissipation, and improving the transformer's heat dissipation performance.

[0031] The second sliding stop (12) is slidably mounted in the first oil inlet intermediate channel (401), and its two sides cooperate with the vertical slide rails on the inner wall of the channel, allowing it to move up and down along the slide rails. When the second sliding stop (12) is in the rising position, it does not block the slow flow channel (402), and the oil can flow into the main oil chamber (201) from the first oil inlet intermediate channel (401) through the slow flow channel (402); when the second sliding stop (12) is lowered, it blocks the slow flow channel (402), preventing the oil from flowing through the channel. The outlet end of the connecting oil pipe (9) is located above the second sliding stop (12) and is connected to the first oil inlet intermediate channel (401).

[0032] When the transformer is running normally, the oil pressure is stable, the second sliding stop (12) is in the rising state, the slow flow channel (402) remains connected, and the oil flows from the inner cavity (101) through the first branch end (301) of the main oil pipe (3) and the slow flow channel (402) of the first oil inlet intermediate channel (401) into the main oil cavity (201). The main oil cavity (201) smoothly adjusts the pressure change of the inner cavity (101) through the principle of communicating vessels. When the oil pressure inside the transformer surges due to increased load or other reasons, the increased oil pressure pushes the second sliding stop (12) down along the slide rail until it blocks the slow flow channel (402) between the first slow flow plate (10) and the second slow flow plate (11). At this time, the oil cannot flow into the main oil chamber (201) through the slow flow channel (402), but instead enters the emergency oil chamber (202) through the second branch end (302) of the main oil pipe (3), thus storing the oil in the emergency oil chamber (202) and preventing a large amount of oil from rushing into the inner cavity (101) and aggravating the pressure rise. When the pressure drops, the oil pressure decreases, and the second sliding stop (12) rises and resets under its own gravity or the action of the reset structure, the slow flow channel (402) is reconnected, and the transformer resumes its normal oil conservator pressure regulation function.

[0033] By setting a second sliding stop (12) that can be raised and lowered in the first oil inlet intermediate channel (401), dynamic control of the on / off state of the slow flow channel (402) is realized. Under normal conditions, the second sliding stop (12) keeps the slow flow channel (402) connected, so that the main oil chamber (201) can smoothly regulate the pressure of the inner cavity (101) through the principle of communicating vessels, ensuring the stability of transformer operation; when the oil pressure rises abnormally, the second sliding stop (12) drops to block the slow flow channel (402), guiding the oil to flow into the emergency oil chamber (202) for storage first, avoiding the oil from flowing back to the inner cavity (101) through the main oil chamber (201), effectively relieving the instantaneous high pressure in the inner cavity (101), and improving the transformer's ability to cope with sudden deflagration accidents. The design of the outlet of the connecting oil pipe (9) located above the second sliding stop (12) ensures that the oil in the emergency oil chamber (202) flows into the main oil chamber (201) through the top of the first oil inlet intermediate channel (401) under the action of pressure difference. This works in conjunction with the blocking function of the second sliding stop (12) to form a graded pressure regulation mechanism, which avoids the impact of oil flow under normal conditions and can quickly isolate the direct connection between the main oil chamber (201) and the inner cavity (101) under high pressure, thereby enhancing the safety protection effectiveness.

[0034] In some examples, pressure valve 13 is installed on the connecting oil pipe 9, and can be positioned near one end or in the middle of the emergency oil chamber 202 to better control the oil pressure flowing from the emergency oil chamber 202 to the main oil chamber 201. During installation, ensure a tight connection between pressure valve 13 and the connecting oil pipe 9, using welding or sealed fittings to prevent oil leakage. Simultaneously, ensure the adjusting nut of pressure valve 13 is easily operable to facilitate adjustment of the connecting pressure during transformer installation, commissioning, or maintenance. When the internal pressure of the transformer begins to rise due to a fault, the oil pressure pushes the first sliding stop 6 to slide, opening the connection between the second oil inlet intermediate channel 501 and the emergency oil chamber 202, allowing oil to flow into the emergency oil chamber 202. As the amount of oil in the emergency oil chamber 202 increases, the pressure gradually rises, but at this point, the pressure in the emergency oil chamber 202 has not yet reached the connecting pressure set by pressure valve 13, so pressure valve 13 remains closed, and oil cannot flow to the main oil chamber 201 through the connecting oil pipe 9. The oil extension pipe 8 acts as a buffer, allowing the oil to flow into the emergency oil chamber 202 more smoothly and avoiding local pressure surges. When the pressure in the emergency oil chamber 202 continues to rise and reaches the connection pressure set by the pressure valve 13, the oil pressure overcomes the spring force, pushing the valve core to move axially, opening the pressure valve 13. The oil then begins to flow from the emergency oil chamber 202 to the first oil inlet intermediate channel 401 through the connecting oil pipe 9, and then to the main oil chamber 201. In this way, oil transfer between the emergency oil chamber 202 and the main oil chamber 201 is achieved to balance the pressure between the two chambers and alleviate excessive pressure inside the transformer. The pressure valve 13 ensures that the oil transfer channel to the main oil chamber 201 is only opened when the pressure in the emergency oil chamber 202 reaches the set value. This avoids the problem of oil transfer being too early or too late due to pressure fluctuations or misoperation, ensuring the stability and reliability of the pressure balancing process between the emergency oil chamber 202 and the main oil chamber 201, and effectively improving the transformer's ability to cope with sudden pressure changes.

[0035] In some examples, the transparent viewing window 203 is made of a high-strength, oil-resistant, and corrosion-resistant transparent material, such as tempered glass or transparent engineering plastics like polycarbonate. To ensure its safety and stability in the transformer operating environment, the edges of the viewing window are specially treated to fit tightly against the outer walls of the main oil chamber 201 and the emergency oil chamber 202. The viewing window is fixed to the outer wall of the oil chamber by sealing rings and fastening bolts. The sealing rings are made of oil-resistant rubber to effectively prevent transformer oil leakage, and the fastening bolts are evenly distributed around the perimeter of the viewing window to ensure a secure installation. Windows adapted to the size of the transparent viewing window 203 are opened at appropriate locations on the outer walls of the main oil chamber 201 and the emergency oil chamber 202. The location of the viewing window must balance the convenience of observation for the operator and the integrity of the oil chamber structure. Generally, it will be placed on the side of the oil conservator 2 that is easy to observe and will not affect the normal operation of other components inside the oil chamber. For larger oil conservators, multiple viewing windows may be provided to offer a more comprehensive observation perspective.

[0036] In some examples, the pressure relief valve 14 is installed at a suitable position on the top of the housing 1, ensuring that one end can extend into the inner cavity 101. During installation, a mounting hole suitable for the valve body is first made on the housing 1, and then the valve body is firmly fixed to the housing 1 by welding or bolting, ensuring the sealing of the connection. The end extending into the inner cavity 101 should avoid interference with the transformer core and other internal components to ensure that the pressure relief valve 14 can work normally. When the pressure in the inner cavity 101 gradually increases due to faults such as winding short circuits or partial discharges, the oil pressure exerts an upward force on the valve core. As the pressure continues to increase, when this force exceeds the spring force, the valve core overcomes the spring force and moves upward, opening the valve port and connecting the inner cavity 101 to the outside. At this time, transformer oil vapor or a small amount of oil is discharged through the pressure relief valve 14 to reduce the pressure in the inner cavity 101. As the oil vapor or oil is discharged, the pressure in the inner cavity 101 gradually decreases. When the pressure drops to the spring-set closing pressure, the spring force exceeds the force exerted by the oil pressure on the valve core. The spring pushes the valve core downward, re-clamping it tightly against the valve seat, closing the valve port, and blocking the connection between the inner cavity 101 and the outside world. The transformer returns to a relatively stable operating state. Throughout the process, the main oil cavity 201 and the emergency oil cavity 202 also adjust the oil distribution in coordination with the action of components such as the first sliding stop 6, according to pressure changes, to assist in pressure regulation. As an important safety protection device, the pressure relief valve 14 can connect the inner cavity 101 to the outside world in time before the pressure in the transformer inner cavity 101 rises to a dangerous level, releasing excessive pressure. This effectively avoids serious consequences such as rupture of the tank 1 and damage to the seals caused by excessive internal pressure, protecting the overall structure and internal components of the transformer and extending the service life of the equipment. Compared to the oil conservator 2 structure, the pressure relief valve 14 here is only a normal pressure control device, used to maintain pressure relief during non-emergency situations.

[0037] In some examples, the heat dissipation fins 102 are evenly distributed along the circumference of the tank 1 on the side wall, with a certain spacing between adjacent fins 102, generally between 5 and 20 mm. This spacing ensures smooth airflow between the fins and makes full use of the space on the side wall of the tank 1 to increase the heat dissipation area. For larger transformers, the heat dissipation fins 102 may be arranged in multiple layers to further improve the heat dissipation effect. At the same time, the installation position of the heat dissipation fins 102 avoids affecting the normal operation of other components of the transformer, such as not obstructing the oil conservator 2, pressure relief valve 14, etc., and facilitates daily inspection and maintenance. The side wall of the tank 1, which is in contact with the hot oil, absorbs heat and transfers the heat to the heat dissipation fins 102 fixed on the side wall. In this process, the oil conservator 2, main oil chamber 201, emergency oil chamber 202, and other components work together to maintain the internal pressure balance of the transformer, and the pressure relief valve 14 provides pressure relief protection when the pressure is too high, ensuring the safe and stable operation of the transformer.

[0038] It should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure and are not intended to limit it. Although this disclosure has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this disclosure without departing from the spirit and scope of the technical solutions of this disclosure, and all such modifications and substitutions should be covered within the scope of the claims of this disclosure.

Claims

1. An oil-immersed distribution transformer, characterized by comprising: include: The housing (1) has an inner cavity (101) for accommodating the transformer core and transformer oil; Oil pillow (2), the oil pillow (2) is installed on the box (1), the oil pillow (2) has a main oil chamber (201) and an emergency oil chamber (202) inside, and the inner cavity (101) is connected to the main oil chamber (201) and the emergency oil chamber (202) respectively; The second guide (5) is disposed in the emergency oil chamber (202). The second guide (5) has a second oil inlet intermediate channel (501) inside, which is used to connect the inner cavity (101) and the emergency oil chamber (202). The first sliding stop (6) is slidably disposed in the second oil inlet intermediate channel (501). The first sliding stop (6) is configured to be pushed and slid by the oil to connect the second oil inlet intermediate channel (501) and the emergency oil chamber (202). The elastic element (7) has one end acting on the side wall of the second oil inlet intermediate channel (501) and the other end acting on the first sliding stop (6) to make the first sliding stop (6) slide to block the connection between the second oil inlet intermediate channel (501) and the emergency oil chamber (202); The inner cavity (101) is connected to the main oil cavity (201) and the emergency oil cavity (202) through the first branch end (301) and the second branch end (302) of the main oil pipe (3), respectively; the second oil inlet intermediate channel (501) is used to connect the second branch end (302) and the emergency oil cavity (202); the oil-immersed distribution transformer further includes: The first guide (4) is disposed in the main oil chamber (201). The first guide (4) has a first oil inlet intermediate channel (401) inside. The first oil inlet intermediate channel (401) is used to connect the first branch end (301) and the main oil chamber (201). The outlet of the first oil inlet intermediate channel (401) is located at the bottom of the main oil chamber (201), and the oil-immersed distribution transformer further includes: The first flow buffer plate (10) is disposed on the top wall of the first oil inlet intermediate channel (401); The second flow-slowing plate (11) is disposed on the bottom wall of the first oil inlet intermediate channel (401); the first flow-slowing plate (10) and the second flow-slowing plate (11) are staggered vertically and laterally, and the sum of the lengths of the first flow-slowing plate (10) and the second flow-slowing plate (11) is greater than the height of the first oil inlet intermediate channel (401) and less than twice the height of the first oil inlet intermediate channel (401). A vertically zigzag flow-slowing channel (402) is formed between the inner walls of the first flow-slowing plate (10), the second flow-slowing plate (11) and the first oil inlet intermediate channel (401). The inlet and outlet of the first oil inlet intermediate channel (401) are located at the two ends of the flow-slowing channel (402).

2. An oil immersed distribution transformer according to claim 1, characterized in that The oil-immersed distribution transformer also includes: Oil circuit extension pipe (8) is installed in the emergency oil chamber (202). The oil circuit extension pipe (8) is used to connect the second oil inlet intermediate channel (501) and the emergency oil chamber (202). The outlet end of the oil circuit extension pipe (8) is higher than the inlet end. A connecting oil pipe (9) is inserted into the emergency oil chamber (202) and the first oil inlet intermediate channel (401) at both ends, for conveying the oil in the emergency oil chamber (202) to the main oil chamber (201) through the connecting oil pipe (9) and the first oil inlet intermediate channel (401).

3. The oil-immersed distribution transformer according to claim 2, characterized in that, The height of the inlet end of the connecting oil pipe (9) in the emergency oil chamber (202) is higher than the height of the outlet end of the oil circuit extension pipe (8).

4. The oil-immersed distribution transformer according to claim 2, characterized in that, The oil-immersed distribution transformer also includes: The second sliding stop (12) is slidably disposed in the first oil inlet intermediate channel (401), and after sliding, it blocks or cancels the blocking of the slow flow channel (402) between the first slow flow plate (10) and the second slow flow plate (11). The outlet of the connecting oil pipe (9) is located above the second sliding stop (12).

5. An oil-immersed distribution transformer according to claim 2, characterized in that, The oil-immersed distribution transformer also includes: Pressure valve (13) is installed on the connecting oil pipe (9) and is used to set the connecting pressure of the connecting oil pipe (9).

6. An oil-immersed distribution transformer according to claim 1, characterized in that, The outer walls of both the main oil chamber (201) and the emergency oil chamber (202) have transparent viewing windows (203).

7. An oil-immersed distribution transformer according to claim 1, characterized in that, The oil-immersed distribution transformer also includes: Pressure relief valve (14) is provided on the housing (1) and one end extends into the inner cavity (101) for connecting the inner cavity (101) to the outside when the pressure in the inner cavity (101) increases.

8. An oil-immersed distribution transformer according to claim 1, characterized in that, The box (1) has several heat dissipation fins (102) on its circumferential sidewalls.

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