Oil-immersed distribution transformer

Abstract

The invention relates to the technical field of transformers, and provides an oil-immersed distribution transformer which comprises a box body, the box body is provided with an inner cavity, and the inner cavity is used for containing a transformer iron core and transformer oil; the oil conservator is arranged on the box body, a main oil cavity and an emergency oil cavity are formed in the oil conservator, and the inner cavity is communicated with the main oil cavity and the emergency oil cavity; the first flow guide part is arranged in the main oil cavity, and a first oil inlet medium channel is formed in the first flow guide part; the second flow guide part is arranged in the emergency oil cavity, a second oil inlet intermediary channel is formed in the second flow guide part, and the second oil inlet intermediary channel is used for communicating the second branch end with the emergency oil cavity; the first sliding blocking piece is arranged in the second oil inlet intermediate channel in a sliding mode. By means of the technical scheme, the technical problem that in the prior art, when an oil-immersed transformer pressure releasing device deals with sudden detonation accidents, the safety protection efficiency is insufficient is solved.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the technical field of transformers, and in particular, to an oil-immersed distribution transformer. Background Art

[0002] Oil-immersed distribution transformers are core equipment in power transmission and distribution systems, and their safe operation is directly related to the stability and reliability of power supply. During actual operation, partial discharge (PD) or arc faults may occur within the transformer due to winding short circuits, insulation aging, or oil degradation. When the fault energy reaches a critical level, the transformer oil rapidly decomposes, producing large amounts 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 a deflagration, which can cause a rapid increase in pressure within the system. Currently, mainstream oil-immersed transformers on the market generally use mechanical pressure relief valves as a safety device. These pressure relief valves are typically set to an opening pressure of 30-50 kPa in accordance with IEC 60076-11. Their design is primarily designed for normal operating conditions such as transformer overload or slow gas generation. However, they struggle to effectively handle the transient high pressures (peaks of up to 150-200 kPa) generated by localized deflagrations. Therefore, the pressure release device in the prior art has the problem of insufficient safety protection effectiveness when dealing with sudden explosion accidents, and there is an urgent need to develop a safety device that can respond quickly and release efficiently. Summary of the Invention

[0003] To overcome the above-mentioned drawbacks, an embodiment of the present disclosure provides an oil-immersed distribution transformer, comprising: A box body having an inner cavity for accommodating a transformer core and transformer oil; An oil pillow is provided on the box body, and has a main oil chamber and an emergency oil chamber inside the oil pillow, wherein the inner chamber is communicated with the main oil chamber and the emergency oil chamber respectively; a second flow guide member, the second flow guide member being disposed in the emergency oil chamber, the second flow guide member having a second oil inlet intermediate passage therein, the second oil inlet intermediate passage being used to connect the inner chamber and the emergency oil chamber; a first sliding stopper, the first sliding stopper being slidably disposed in the second oil inlet intermediary channel, the first sliding stopper being configured to be pushed and slid by the oil so as to connect the second oil inlet intermediary channel with the emergency oil chamber; An elastic member, one end of which acts on the side wall of the second oil inlet intermediary channel, and the other end acts on the first sliding stopper, so as to enable the first sliding stopper to slide and block the communication between the second oil inlet intermediary channel and the emergency oil chamber.

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

[0005] For example, at least one embodiment of the present disclosure provides an oil-immersed distribution transformer, which further includes: an oil circuit extension pipe, the oil circuit extension pipe being disposed in the emergency oil chamber and being used to connect the second oil inlet intermediate channel and the emergency oil chamber, with an outlet end of the oil circuit extension pipe being higher than an inlet end; A connecting oil pipe, both ends of which are respectively inserted into the emergency oil chamber and the first oil inlet intermediary channel, is used to pass the oil in the emergency oil chamber to the main oil chamber through the connecting oil pipe and the first oil inlet intermediary channel.

[0006] For example, in at least one embodiment of the present disclosure, an oil-immersed distribution transformer is provided, wherein 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 extension pipe.

[0007] For example, in at least one embodiment of the present disclosure, an oil-immersed distribution transformer is provided, 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: a first slow-flow plate, the first slow-flow plate being arranged on a top wall of the first oil inlet intermediate channel; The second slow flow plate is arranged on the bottom wall of the first oil inlet intermediary channel; the first slow flow plate and the second slow flow plate are arranged up and down and laterally staggered, and the sum of the lengths of the first slow flow plate and the second slow flow plate is greater than the height of the first oil inlet intermediary channel and less than twice the height of the first oil inlet intermediary channel, a vertical broken line slow flow channel is formed between the first slow flow plate, the second slow flow plate and the inner wall of the first oil inlet intermediary channel, and the inlet and outlet of the first oil inlet intermediary channel are respectively located at the two ends of the slow flow channel.

[0008] For example, at least one embodiment of the present disclosure provides an oil-immersed distribution transformer, which further includes: The second sliding stopper is set in the first oil inlet intermediate channel for lifting and sliding, and blocks or unblocks the slow flow channel between the first slow flow plate and the second slow flow plate after sliding, and the outlet of the connecting oil pipe is located above the second sliding stopper.

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

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

[0011] For example, at least one embodiment of the present disclosure provides an oil-immersed distribution transformer, which further includes: A pressure relief valve is provided on the box body, and one end of the pressure relief valve extends into the inner cavity, and is used to connect the inner cavity with the outside when the pressure in the inner cavity increases.

[0012] For example, at least one embodiment of the present disclosure provides an oil-immersed distribution transformer, wherein the circumferential side walls of the box body are provided with a plurality of heat dissipation fins.

[0013] The beneficial effects of the embodiments of the present disclosure are: In the present disclosure, by setting up a main oil chamber and an emergency oil chamber, and utilizing the two branch ends of the main oil pipe to communicate with the inner cavity respectively, the main oil chamber plays a conventional pressure regulating role during normal operation, and in the case of a sudden increase in oil pressure, the emergency oil chamber is quickly activated and works in conjunction with the main oil chamber, significantly enhancing the transformer's ability to cope with sudden pressure changes and avoiding damage to the transformer due to excessive pressure. The design of the first sliding stopper and the elastic part enables the emergency oil chamber to open quickly when the oil pressure rises, and promptly accept the oil flowing in from the inner cavity of the box, achieving a rapid response to sudden pressure changes, effectively alleviating internal pressure, and ensuring the safe operation of the transformer. The non-reflux design of the emergency oil chamber accurately 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, a violent reaction caused by continued expansion of the oil is effectively prevented, providing a guarantee for the stable operation of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] To more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following briefly describes the drawings required for use in describing the embodiments of the present disclosure. Obviously, the drawings described below are merely some exemplary embodiments of the present disclosure. Those skilled in the art can, without inventive effort, derive other drawings based on the content of the exemplary embodiments of the present disclosure and these drawings.

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

[0016] In the figure: box body-1, inner cavity-101, heat dissipation fin-102, oil pillow-2, main oil chamber-201, emergency oil chamber-202, transparent visual window-203, main oil pipe-3, first branch end-301, second branch end-302, first flow guide member-4, first oil inlet intermediary channel-401, slow flow channel-402, second flow guide member-5, second oil inlet intermediary channel-501, first sliding stopper-6, elastic member-7, oil circuit extension pipe-8, connecting oil pipe-9, first slow flow plate-10, second slow flow plate-11, second sliding stopper-12, pressure valve-13, pressure relief valve-14, gas buffer chamber-15, one-way exhaust valve 16. DETAILED DESCRIPTION

[0017] The present disclosure will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure, rather than to limit the present disclosure.

[0018] To simplify the drawings, only the parts relevant to the disclosure are schematically shown in each figure; they do not represent the actual structure of the product. Furthermore, to simplify the drawings and facilitate understanding, in some figures, only one of the components with the same structure or function is schematically shown or labeled. In this document, "one" not only means "only one" but also "more than one," and "several" includes "two" and "more than two."

[0019] It should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure based on the specific circumstances.

[0020] In the present disclosure, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0021] In the description of this embodiment, the terms "up", "down", "left", "right", etc., and the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present disclosure.

[0022] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0023] like Figures 1 to 5As shown, it shows an oil-immersed distribution transformer in one embodiment of the present disclosure. The box 1 serves as the outer shell of the transformer, which can withstand the pressure under normal internal working conditions. At the same time, it can also withstand certain deformation while maintaining sealing performance when the internal pressure increases sharply. The space size of the inner cavity 101 is designed according to the specifications and capacity of the transformer, providing sufficient accommodation space for the transformer core and a sufficient amount of transformer oil. On the box 1, an interface for connecting the main oil pipe 3 is provided to ensure communication with the main oil chamber 201 and the emergency oil chamber 202 of the oil pillow 2. The oil pillow 2 is installed at a suitable position on the top or side of the box 1, and its structural design is intended to meet the transformer's needs for oil regulation and storage under different working conditions. The main oil chamber 201 and the emergency oil chamber 202 are connected to the inner cavity 101 of the box 1 through a three-way channel. The material of the oil pillow 2 is compatible with the box 1 and also has good sealing and corrosion resistance. During normal operation, the main oil chamber 201 maintains communication with the inner chamber 101 through the first branch end 301 of the main oil pipe 3, acting as a communicating vessel and smoothly adapting to pressure changes caused by changes in oil density. The emergency oil chamber 202 serves as a backup oil chamber and is used in emergency situations. The first guide member 4 is placed in the main oil chamber 201 to ensure that the transformer oil can flow smoothly from the first branch end 301 into the main oil chamber 201. The second guide member 5 is set in the emergency oil chamber 202. Its structure and material are similar to those of the first guide member 4. The second oil inlet intermediate channel 501 also passes through the second guide member 5 to achieve communication between the second branch end 302 and the emergency oil chamber 202. The design of this channel is intended to control the opening and closing of the oil flow into the emergency oil chamber 202 to meet emergency needs in sudden situations. The first sliding stopper 6 is piston-shaped or sheet-shaped. Its external dimensions are closely adapted to the inner diameter of the second oil inlet intermediate channel 501. It can slide flexibly within the channel while ensuring good sealing to prevent oil leakage. The first sliding stopper 6 is made of a lightweight, high-strength, oil-resistant material, such as polytetrafluoroethylene (PTFE) or aluminum alloy. Its surface is smoothed to reduce friction when sliding within the channel. When the oil pressure within the transformer is normal, the first sliding stopper 6, under the action of the elastic member 7, blocks the connection between the second oil inlet intermediate channel 501 and the emergency oil chamber 202, placing the emergency oil chamber 202 in a closed, standby state. If the oil pressure rises abnormally, the elastic member 7 will compress, causing the first sliding stopper 6 to slide.

[0024] The specific working process is as follows: when the transformer is operating normally, the transformer oil is kept in communication between the inner cavity 101 of the housing 1 and the main oil cavity 201 of the oil pillow 2 through the first branch end 301 of the main oil pipe 3 and the first oil inlet intermediate channel 401 of the first flow guide 4. Utilizing the principle of a communicating vessel, the transformer oil smoothly adapts to pressure changes caused by changes in oil density. At this time, the first sliding block 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, and the oil in the emergency oil cavity 202 is in a static standby state. When the oil pressure inside the transformer increases rapidly due to local discharge, arc fault, or other reasons, the increased oil pressure pushes the transformer oil through the second branch end 302 of the main oil pipe 3 and into the second oil inlet intermediate channel 501 of the second flow guide 5. The oil pressure overcomes the elastic force of the elastic member 7, pushing the first sliding stopper 6 to slide in the second oil inlet intermediate channel 501, removing the obstruction to the connection between the channel and the emergency oil chamber 202, and the transformer oil quickly flows into the emergency oil chamber 202. The main oil chamber 201 and the emergency oil chamber 202 simultaneously serve as oil chamber reserves, relieving the pressure inside the housing 1. When the pressure is quickly released, the oil pressure decreases, and the elastic force of the elastic member 7 pushes the first sliding stopper 6 to slide back in 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 to the inner cavity 101. The reduced total amount of oil is maintained in the inner cavity 101, avoiding the violent reaction that may be caused by the subsequent expansion of the oil. The transformer enters a relatively stable operating state, and the emergency oil chamber 202 continues to remain in a standby state.

[0025] In general, by setting up the main oil chamber 201 and the emergency oil chamber 202, and using the two branch ends of the main oil pipe 3 to communicate with the inner cavity 101 respectively, the main oil chamber 201 plays a conventional pressure regulating role during normal operation, and in the event of a sudden increase in oil pressure, the emergency oil chamber 202 is quickly activated and works in conjunction with the main oil chamber 201, significantly enhancing the transformer's ability to cope with sudden pressure changes and avoiding damage to the transformer due to excessive pressure. The design of the first sliding stopper 6 and the elastic member 7 enables the emergency oil chamber 202 to open quickly when the oil pressure rises, and promptly receive the oil flowing in from the inner cavity 101 of the box body 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 accurately 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, a violent reaction caused by continued expansion of the oil is effectively prevented, providing a strong guarantee for the stable operation of the transformer.

[0026] In some examples, the oil circuit extension tube 8 is made of an oil-resistant and pressure-resistant metal material, such as stainless steel, and its length is customized according to the internal space size of the emergency oil chamber 202 and actual needs. The selection of the pipe diameter needs to comprehensively consider the oil flow rate and flow resistance to ensure that the oil can pass smoothly when the oil pressure changes. When the oil pressure inside the transformer increases rapidly, the oil pressure pushes the first sliding block 6 to slide, removing the obstruction to the second oil inlet intermediary channel 501. At this time, the transformer oil flows from the second oil inlet intermediary channel 501 into the inlet end of the oil circuit extension tube 8. Since the outlet end of the oil circuit extension tube 8 is higher than the inlet end, the oil will encounter a certain resistance when flowing in the tube, so that the oil cannot instantly flow into the emergency oil chamber 202 in large quantities, but flows in relatively smoothly, avoiding problems such as local pressure shock and oil splashing that may be caused by the sudden influx of oil into the emergency oil chamber 202. When the pressure is quickly released, the small amount of oil remaining in the oil extension tube 8 will not flow back to the second oil inlet intermediate channel 501 under the action of gravity, but will remain in the oil extension tube 8, further ensuring that the oil in the emergency oil chamber 202 will not flow back to the inner chamber 101, maintaining the total amount of oil in the inner chamber 101 after the reduction, and preventing subsequent oil expansion from causing violent reactions. The design of the outlet end of the oil extension tube 8 being higher than the inlet end provides a buffer process for the oil to flow into the emergency oil chamber 202. When the oil pressure suddenly changes, the instantaneous influx of oil is avoided, 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 internal pressure of the transformer. The oil will not suddenly flow in large quantities, which is not only conducive to maintaining the orderly distribution of the oil in the emergency oil chamber 202, but also avoids the situation where the oil is not rising smoothly, which may affect the normal operation of internal components or cause local poor sealing.

[0027] In some examples, the diameter of the connecting oil pipe 9 is determined based on the demand for oil flow between the emergency oil chamber 202 and the main oil chamber 201, and is generally between 1 and 5 cm, which ensures that the oil can flow smoothly while avoiding the situation where the pipe diameter is too large and affects the internal structure layout of the oil pillow 2. One end of the connecting oil pipe 9 is precisely inserted into the emergency oil chamber 202. As the oil in the emergency oil chamber 202 continues to increase, the internal pressure continues to rise. Since the emergency oil chamber 202 has no air outlet, and the pressure control valve at the air outlet of the main oil chamber 201 is in a closed state when the pressure of the main oil chamber 201 does not reach the threshold, the pressure in the emergency oil chamber 202 is higher than that in the main oil chamber 201. Under the action of the pressure difference, the oil in the emergency oil chamber 202 is pressed into the first oil inlet intermediate channel 401 through the connecting oil pipe 9, and then flows to the main oil chamber 201. As the oil is transferred, the pressure in the main oil chamber 201 gradually increases. When the opening threshold of the outlet pressure control valve is reached, the pressure control valve opens, and the excess gas in the main oil chamber 201 is discharged, maintaining the pressure of the main oil chamber 201 within a certain range, and continuously ensuring the pressure difference between the emergency oil chamber 202 and the main oil chamber 201, so that the oil continues to transfer. When the pressure of the main oil chamber 201 drops to the closing threshold of the outlet pressure control valve, the pressure control valve closes. At this time, the oil transferred to the main oil chamber 201 through the connecting oil pipe 9, together with the original oil in the main oil chamber 201, continues to participate in the pressure regulation process between the main oil chamber 201 and the inner cavity 101. A certain amount of oil is retained in the emergency oil chamber 202 for use when the pressure suddenly changes next time, and the transformer gradually returns to a relatively stable operating state. By utilizing the pressure difference between the emergency oil chamber 202 and the main oil chamber 201, the oil is automatically transferred from the emergency oil chamber 202 to the main oil chamber 201 without the need for an additional pumping device, effectively balancing the oil height and pressure between the two chambers. This automatic adjustment mechanism responds quickly when the transformer pressure suddenly changes, effectively avoiding damage to the emergency oil chamber 202 due to excessive pressure, and ensuring the safe and stable operation of the transformer under complex working conditions. The connecting oil pipe 9 makes more full use of the space of the main oil chamber 201, and can receive excess oil in the emergency oil chamber 202 in emergency situations, avoiding the problem of oil overflow or ineffective pressure relief due to the limited capacity of the emergency oil chamber 202. This optimized utilization of the internal space of the oil pillow improves the overall efficiency of the oil pillow as an oil regulating 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 makes the timing of the oil transfer from the emergency oil chamber 202 to the main oil chamber 201 more accurate. Only when the oil in the emergency oil chamber 202 accumulates to a certain level will the transfer of the oil to the main oil chamber 201 be triggered, avoiding premature transfer when the amount of oil in the emergency oil chamber 202 is small, and ensuring that the emergency oil chamber 202 can fully play the role of buffering pressure in the early stage. This height difference design helps to stabilize the speed of oil transfer from the emergency oil chamber 202 to the main oil chamber 201. Since the oil needs to accumulate to a certain height before entering the connecting oil pipe 9, it can avoid the excessive flow rate caused by the instantaneous influx of a large amount of oil into the connecting oil pipe 9, thereby affecting the pressure balance and oil distribution in the main oil chamber 201, making the oil transfer process more stable and orderly. When the pressure suddenly changes, 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 the 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, avoid damage to the internal structure of the transformer due to excessive instantaneous pressure changes, and improve the safety of the transformer in the event of a sudden pressure change. Reasonable oil transfer control makes the oil distribution in the emergency oil chamber 202 and the main oil chamber 201 more reasonable. During the pressure mutation process, the emergency oil chamber 202 can gradually transfer the oil to the main oil chamber 201 according to the actual pressure conditions, avoiding the pressure regulation effect affected by too much or too little oil in a certain oil chamber, which helps to maintain the balance and stability of the internal pressure of the transformer.

[0029] In some examples, both the first slow-flow plate 10 and the second slow-flow plate 11 are made of oil-resistant, corrosion-resistant metal sheet, such as stainless steel. Their shape is designed based on the internal space of the first oil inlet intermediate channel 401 and is typically rectangular, slightly smaller than the cross-sectional dimensions of the first oil inlet intermediate channel 401. Once installed, they enable the fluid to flow in an "S"-shaped path. The surfaces of the slow-flow plates are smoothed to reduce resistance to the fluid flow. This staggered arrangement aims to achieve a slow-flow effect by altering the fluid's flow path, increasing the distance and time the fluid travels within the channel. After entering the slow-flow channel 402 from the inlet, the fluid first impacts the first slow-flow plate 10, changing its direction. It then flows downward along the surface of the first slow-flow plate 10, changing direction again upon encountering the second slow-flow plate 11, and ultimately exiting through the outlet. This zigzag flow path effectively reduces the fluid's velocity, allowing it to enter the main oil chamber 201 more smoothly.

[0030] The zigzag slow-flow channel 402 formed by the first slow-flow plate 10 and the second slow-flow plate 11 effectively extends the flow path of the oil in the first oil inlet intermediate channel 401, significantly reducing the flow rate of the oil. This helps to avoid the large impact force generated by the oil when entering the main oil chamber 201 due to the excessively fast flow rate, prevents damage to the windings and other components in the main oil chamber 201, and ensures the stability of the internal structure of the transformer. The slow-flow channel 402 changes the flow direction of the oil multiple times, avoiding the situation where the oil flows concentrated in a certain area, thereby improving the heat dissipation efficiency. The synergistic effect of the oil inlet at the bottom of the first oil inlet intermediate channel 401 and the oil outflowing from the slow-flow channel 402 helps to promote the natural convection of the oil in the main oil chamber 201. Under the guidance and buffering of the oil outflowing from the slow-flow channel 402, the new oil entering from the bottom can more smoothly push the hot oil upward, so that the oil forms a good natural convection cycle in the main oil chamber 201, accelerates the transfer and dissipation of heat, and improves the heat dissipation performance of the transformer.

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

[0032] When the transformer is operating normally, the oil pressure is stable, the second sliding stopper (12) is in an ascending 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 communicating vessel principle. When the oil pressure inside the transformer soars due to reasons such as increased load, the increased oil pressure pushes the second sliding block (12) down along the slide rail until the slow flow channel (402) between the first slow flow plate (10) and the second slow flow plate (11) is blocked. At this time, the oil cannot flow into the main oil chamber (201) through the slow flow channel (402), but enters the emergency oil chamber (202) through the second branch end (302) of the main oil pipe (3), thereby storing the oil in the emergency oil chamber (202) and preventing a large amount of oil from pouring into the inner chamber (101) and aggravating the pressure increase. When the pressure drops, the oil pressure decreases, and the second sliding block (12) rises and resets under its own gravity or the action of the reset structure, and the slow flow channel (402) is reconnected, and the transformer resumes the normal oil pillow pressure regulation function.

[0033] By arranging a second sliding blocker (12) that can be lifted and slid in the first oil inlet intermediate channel (401), dynamic control of the on-off state of the slow flow channel (402) is achieved. Under normal conditions, the second sliding blocker (12) keeps the slow flow channel (402) connected, so that the main oil chamber (201) can smoothly adjust the pressure of the inner chamber (101) through the communicating vessel principle, thereby ensuring the stability of transformer operation; when the oil pressure increases abnormally, the second sliding blocker (12) descends to block the slow flow channel (402), guiding the oil to flow into the emergency oil chamber (202) for storage first, preventing the oil from flowing back to the inner chamber (101) through the main oil chamber (201), effectively alleviating the instantaneous high pressure of the inner chamber (101), and improving the ability of the transformer to cope with sudden explosion accidents. The design of the outlet of the connecting oil pipe (9) being located above the second sliding stopper (12) ensures that the oil in the emergency oil chamber (202) needs to flow into the main oil chamber (201) through the top of the first oil inlet intermediate channel (401) under the action of the pressure difference, and cooperates with the blocking function of the second sliding stopper (12) to form a graded pressure regulation mechanism, which not only avoids the impact of oil flow under normal conditions, but also can quickly isolate the direct connection between the main oil chamber (201) and the inner chamber (101) under high pressure, thereby enhancing the safety protection performance.

[0034] In some examples, the pressure valve 13 is installed on the connecting oil pipe 9, either near one end of the emergency oil chamber 202 or in the middle, to better control the pressure of the oil flowing from the emergency oil chamber 202 to the main oil chamber 201. During installation, ensure that the pressure valve 13 is tightly connected to the connecting oil pipe 9, using welding or sealed pipe fittings to prevent oil leakage. At the same time, the adjusting nut of the pressure valve 13 must be easily accessible 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 stopper 6 to slide, opening the connection between the second oil inlet intermediary 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. However, at this point, the pressure in the emergency oil chamber 202 has not yet reached the connecting pressure set by the pressure valve 13. The pressure valve 13 remains closed, and oil cannot flow through the connecting oil pipe 9 to the main oil chamber 201. The oil extension tube 8 acts as a buffer, allowing oil to flow more smoothly into the emergency oil chamber 202 and avoiding localized pressure shocks. 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 axially, opening the pressure valve 13. Oil then begins to flow from the emergency oil chamber 202 through the connecting oil pipe 9 to the first oil inlet intermediate channel 401, 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, balancing the pressure between the two chambers and alleviating excessive pressure within the transformer. The pressure valve 13 ensures that the oil transfer channel to the main oil chamber 201 is opened only when the pressure in the emergency oil chamber 202 reaches the set value. This avoids premature or delayed oil transfer due to pressure fluctuations or misoperation, ensures the stability and reliability of the pressure balancing process between the emergency oil chamber 202 and the main oil chamber 201, and effectively improves 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 safety and stability during transformer operation, the edges of the viewing window are specially treated to ensure a tight fit with the outer walls of the main oil chamber 201 and the emergency oil chamber 202. The viewing window is secured to the outer walls of the oil chambers using a sealing rubber ring and fastening bolts. The sealing rubber ring is made of oil-resistant rubber and effectively prevents transformer oil leakage. The fastening bolts are evenly distributed around the viewing window to ensure a secure installation. Windows of appropriate size to the transparent viewing window 203 are provided 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 should balance operator convenience and the integrity of the oil chamber structure. Generally, it is located on a side of the oil pillow 2 that is easily observable and does not affect the normal operation of other components within the oil chamber. For larger oil pillows, multiple viewing windows may be provided to provide a more comprehensive viewing angle.

[0036] In some examples, the pressure relief valve 14 is installed at a suitable location on the top of the housing 1, ensuring that one end of the valve can extend into the inner cavity 101. During installation, a mounting hole is first opened in the housing 1 to accommodate the valve body. The valve body is then securely fastened to the housing 1 by welding or bolting, ensuring a tight seal at the joint. The end extending into the inner cavity 101 should avoid interference with the transformer core and other internal components to ensure proper function of the pressure relief valve 14. When the pressure in the inner cavity 101 gradually increases due to a transformer fault such as a winding short circuit or partial discharge, the oil pressure exerts an upward force on the valve core. As the pressure continues to increase, when this force exceeds the set 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 world. At this point, transformer oil vapor or a small amount of oil is discharged through the pressure relief valve 14, reducing 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 closing pressure set by the spring, the elastic force of the spring is greater than the force of the oil pressure on the valve core. The spring pushes the valve core downward, tightly fitting the valve seat again, closing the valve port, blocking the connection between the inner cavity 101 and the outside world, and the transformer returns to a relatively stable operating state. During the entire process, the main oil chamber 201 and the emergency oil chamber 202 will also adjust the oil distribution in coordination according to the pressure changes through the action of the first sliding stopper 6 and other components 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 to release excessive pressure before the pressure in the transformer inner cavity 101 rises to a dangerous level. This effectively avoids serious consequences such as the rupture of the box 1 and damage to the seals due to excessive internal pressure, protects the overall structure and internal components of the transformer, and extends the service life of the equipment. Compared with the oil pillow 2 structure, the pressure relief valve 14 here is only a normalized pressure control device, which is used to maintain the pressure relief work of pressure growth in non-emergency situations.

[0037] In some examples, the cooling fins 102 are evenly distributed along the circumference of the housing 1 on the sidewalls, with a certain spacing between adjacent cooling fins 102, typically between 5 and 20 mm. This spacing ensures smooth air flow between the fins while fully utilizing the space on the sidewalls of the housing 1 to increase the heat dissipation area. For larger transformers, the cooling fins 102 may be arranged in multiple layers to further enhance heat dissipation. Furthermore, the installation position of the cooling fins 102 avoids interfering with the normal operation of other transformer components, such as obstructing the oil pillow 2 and pressure relief valve 14, and facilitates routine inspection and maintenance. The sidewalls of the housing 1 in contact with the hot oil absorb heat and transfer it to the cooling fins 102 fixed to the sidewalls. During this process, the oil pillow 2, main oil chamber 201, and emergency oil chamber 202 work together to maintain pressure balance within the transformer. The pressure relief valve 14 provides pressure relief protection when the pressure is too high, ensuring 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 the present disclosure and are not limiting. Although the present disclosure has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present disclosure may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present disclosure, and all of these should be included in the scope of the claims of the present disclosure.

Claims

1. An oil-immersed distribution transformer, characterized in that: include: A box (1), the box (1) having an inner cavity (101), the inner cavity (101) being used to accommodate a transformer core and transformer oil; An oil pillow (2), the oil pillow (2) being arranged on the box body (1), the oil pillow (2) having a main oil chamber (201) and an emergency oil chamber (202) therein, the inner cavity (101) being in communication with the main oil chamber (201) and the emergency oil chamber (202), respectively; A second flow guide member (5), the second flow guide member (5) being arranged in the emergency oil chamber (202), the second flow guide member (5) having a second oil inlet intermediate passage (501) therein, the second oil inlet intermediate passage (501) being used to connect the inner chamber (1) and the emergency oil chamber (202); a first sliding stopper (6), the first sliding stopper (6) being slidably disposed in the second oil inlet intermediate passage (501), the first sliding stopper (6) being configured to be pushed and slid by oil so as to connect the second oil inlet intermediate passage (501) with the emergency oil chamber (202); An elastic member (7), one end of which acts on the side wall of the second oil inlet intermediary channel (501), and the other end of which acts on the first sliding stopper (6), so as to enable the first sliding stopper (6) to slide and block the communication between the second oil inlet intermediary channel (501) and the emergency oil chamber (202).

2. The oil-immersed distribution transformer according to claim 1, characterized in that: The inner cavity (101) is communicated with the main oil cavity (201) and the emergency oil cavity (202) respectively through the first branch end (301) and the second branch end (302) of the main oil pipe (3); the inner cavity (101) is communicated with the main oil cavity (201) and the emergency oil cavity (202) respectively through the first branch end (301) and the second branch end (302) of the main oil pipe (3); the second oil inlet intermediate channel (501) is used to communicate with the second branch end (302) and the emergency oil cavity (202); the oil-immersed distribution transformer further comprises: A first flow guide member (4), the first flow guide member (4) being arranged in the main oil chamber (201), the first flow guide member (4) having a first oil inlet intermediate channel (401) therein, the first oil inlet intermediate channel (401) being used to connect the first branch end (301) and the main oil chamber (201).

3. The oil-immersed distribution transformer according to claim 2, characterized in that: The oil-immersed distribution transformer further comprises: An oil circuit extension tube (8), the oil circuit extension tube (8) being arranged in the emergency oil chamber (202), the oil circuit extension tube (8) being used to connect the second oil inlet intermediate channel (501) and the emergency oil chamber (202), and the outlet end of the oil circuit extension tube (8) being higher than the inlet end; A connecting oil pipe (9), with both ends of the connecting oil pipe (9) respectively inserted into the emergency oil chamber (202) and the first oil inlet intermediate channel (401), for passing 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).

4. The oil-immersed distribution transformer according to claim 3, characterized in that: The height of the inlet end of the communicating 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).

5. The oil-immersed distribution transformer according to claim 3, characterized in that: 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: a first slow flow plate (10), the first slow flow plate (10) being arranged on a top wall of the first oil inlet intermediate channel (401); A second slow flow plate (11), the second slow flow plate (11) is arranged on the bottom wall of the first oil inlet intermediate channel (401); the first slow flow plate (10) and the second slow flow plate (11) are arranged vertically and transversely staggered, and the sum of the lengths of the first slow flow plate (10) and the second slow flow 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 slow flow channel (402) is formed between the first slow flow plate (10), the second slow flow plate (11) and the inner wall of the first oil inlet intermediate channel (401); the inlet and the outlet of the first oil inlet intermediate channel (401) are respectively located at two ends of the slow flow channel (402).

6. The oil-immersed distribution transformer according to claim 5, characterized in that: The oil-immersed distribution transformer further comprises: A second sliding stopper (12) is provided in the first oil inlet intermediate channel (401) in a lifting and sliding manner, and blocks or unblocks the slow flow channel (402) between the first slow flow plate (10) and the second slow flow plate (11) after sliding, and the outlet of the connecting oil pipe (9) is located above the second sliding stopper (12).

7. The oil-immersed distribution transformer according to claim 3, characterized in that: The oil-immersed distribution transformer further comprises: A pressure valve (13) is provided on the communicating oil pipe (9) and is used to set the communicating pressure of the communicating oil pipe (9).

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

9. The oil-immersed distribution transformer according to claim 1, characterized in that: The oil-immersed distribution transformer further comprises: A pressure relief valve (14) is provided on the box body (1), and one end of the pressure relief valve (14) extends into the inner cavity (101), and is used to connect the inner cavity (101) with the outside when the pressure in the inner cavity (101) increases.

10. The oil-immersed distribution transformer according to claim 1, characterized in that: The box body (1) has a plurality of heat dissipation fins (102) on the circumferential side walls.

Images