Energy-saving oil-immersed power transformer

Abstract

This invention relates to the field of transformer technology and discloses an energy-saving oil-immersed power transformer, comprising a housing, a core winding assembly, and an oil conservator. The housing contains a first partition and a second partition. The first partition divides the inner cavity of the housing into a lower oil chamber and an upper oil chamber, while the second partition divides the upper oil chamber into an installation chamber and a flow chamber. The core winding assembly is installed in the installation chamber, and the lower oil chamber communicates with the oil conservator. By directly installing the first and second partitions inside the housing, along with a sludge collection container and filter balls integrated into the first partition, the rotating plates, brushes, and corresponding drive transmission mechanisms of traditional solutions are replaced, significantly reducing the number of moving parts and lowering the manufacturing difficulty and production cost.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and specifically to an energy-saving oil-immersed power transformer. Background Technology

[0002] Oil-immersed power transformers are widely used in urban power supply, industrial power supply, and other fields. During operation, the copper coils, iron core, and other metal components inside the transformer experience wear due to long-term vibration and thermal expansion. The resulting metal particles mix into the transformer oil. Furthermore, if an electric arc or partial discharge occurs during operation, carbon black and metal particles will be generated. These impurities, suspended in the transformer oil, not only reduce the oil's insulation and heat dissipation performance but also accumulate throughout the transformer's interior, adversely affecting its normal operation. To address the problem of impurity filtration in transformer oil, various technical solutions have been proposed. For example, Chinese patent document CN202411058028 discloses a high-efficiency oil-immersed power transformer that uses rotating plates and brushes within the housing cavity to mechanically clean impurities deposited at the bottom of the cavity. However, this solution is structurally complex, requiring rotating plates, brushes, and corresponding drive transmission mechanisms, resulting in high manufacturing costs. Additionally, the brushes are prone to wear after long-term operation, affecting the cleaning effect. On the other hand, a common filtration method in existing technology is to install an independent filtration device on the external pipeline of the transformer, using an oil pump to drive the oil to circulate through a filter screen or filter cylinder to trap impurities. However, this type of external filtration solution increases the complexity of the pipeline and the energy consumption of oil circulation, and it cannot effectively collect and filter impurities deposited at the bottom inside the transformer in situ. Summary of the Invention

[0003] The main objective of this invention is to provide an energy-saving oil-immersed power transformer to solve the problems of existing high-efficiency oil-immersed power transformers, which have complex structures, require rotating plates, brushes and corresponding drive transmission mechanisms, have high manufacturing costs, and are prone to wear after long-term operation, affecting the cleaning effect.

[0004] To achieve the above objectives, the present invention provides an energy-saving oil-immersed power transformer, comprising a housing, a core winding assembly, and an oil conservator. The housing is provided with a first partition and a second partition. The first partition divides the inner cavity of the housing into a lower oil cavity and an upper oil cavity. The second partition divides the upper oil cavity into an installation cavity and a flow cavity. The core winding assembly is installed in the installation cavity. The lower oil cavity is connected to the oil conservator. The first partition has at least a horizontal section. The horizontal section located in the installation cavity is a first filter plate. The first filter plate is provided with at least one sludge collection container with an open top. The sludge collection container is located below the core winding assembly, and its bottom wall is constructed as a second filter plate. The sludge collection container contains multiple layers of filter balls, with each layer having the same diameter, and the diameter of the filter balls increasing from bottom to top.

[0005] Preferably, the mesh size of the second filter plate is smaller than the diameter of the filter ball located at the bottom layer.

[0006] Preferably, the first partition further includes a flow guiding inclined section, the downstream end of which is located obliquely above the first filter plate, and the opening of the sludge collection container is connected to the lower downstream side of the flow guiding inclined section.

[0007] Preferably, the first partition further includes a vertical guide section, the inclined guide section, the vertical guide section and the first filter plate are connected in sequence, the vertical guide section and the inner wall of the box form a limiting slide, and the sludge collection container is slidably disposed in the limiting slide.

[0008] Preferably, the energy-saving oil-immersed power transformer also includes a circulation pipeline and a displacement drive mechanism. The circulation pipeline is vertically arranged, with one end connected to the flow cavity and the other end connected to the oil conservator. A maintenance vertical pipe is also connected to the oil conservator. The maintenance vertical pipe is located in the extension direction of the circulation pipeline and has a removable maintenance cover at its end. The horizontal section located in the flow cavity is a support plate. The support plate has an oil passage hole. The lower oil cavity passes through the oil passage hole, the flow cavity, the circulation pipeline, the oil tank and the maintenance riser to form a vertical working channel. The second partition has a channel opening at one end near the first filter plate, and the shifting drive mechanism can drive the sludge collection container to move along the limiting slide to the bottom of the vertical working channel.

[0009] Preferably, the shifting drive mechanism includes a hydraulic cylinder; The sludge collection container is a rectangular shell, and there are multiple of them. Each of the two opposite outer side walls is provided with a first magnetic suction element. A transverse through hole is provided on the second partition plate. A transmission rod is connected to the piston rod of the oil cylinder. The transmission rod passes through the transverse through hole and is fixed with a second magnetic attractor. The second magnetic attractor is used to magnetically connect with the first magnetic attractor.

[0010] Preferably, a portion of the sidewall of the sludge collection container is located within the channel opening to conceal it.

[0011] Preferably, the inspection cover has a threaded hole and a lifting screw is screwed to it. Each sludge collection container is fixedly provided with a connecting bracket and a threaded sleeve is fixedly provided on the connecting bracket. The lifting screw can be threadedly connected to the threaded sleeve.

[0012] Preferably, the energy-saving oil-immersed power transformer also includes a sealed protective cover, which is fixed to the inner wall of the tank. The oil cylinder is installed inside the sealed protective cover, and its piston rod passes through the sealed protective cover and is connected to the transmission rod.

[0013] The beneficial effects of the above scheme are: By directly installing the first and second partitions, along with the sludge collection container and filter balls integrated into the first partition, the traditional rotating plates, brushes, and corresponding drive transmission mechanisms are replaced. This significantly reduces the number of moving parts, lowers the manufacturing difficulty and production cost, and avoids the problem of reduced cleaning effect caused by long-term wear of the brushes. The sludge collection container is located directly below the iron core winding assembly, naturally collecting impurities such as metal particles and carbon black generated by vibration, thermal expansion, or arc discharge, achieving in-situ collection. The multi-layered filter ball structure inside the container, with the diameter increasing from bottom to top, forms a gradient filtration channel: the smaller balls in the lower layer intercept fine impurities, while the larger balls in the upper layer intercept coarse particles. This ensures smooth oil flow, avoids clogging of a single filter layer, and extends the service life of the filter media through layered interception, reducing the frequency of downtime maintenance. The sludge collection and filtration functions are integrated inside the transformer tank, eliminating the need for an external independent filtration device and additional oil pump circulation pipelines. This avoids complicated external pipelines and additional oil circulation power consumption, further demonstrating energy-saving effects. Attached Figure Description

[0014] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0015] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a cross-sectional structural schematic diagram of the present invention; Figure 3 yes Figure 2 Enlarged structural diagram of region A in the middle; Figure 4 yes Figure 2 A schematic diagram of the frontal view of the structure; Figure 5 This is a cross-sectional view of another state of the present invention; Figure 6 yes Figure 5 A magnified structural diagram of region B in the middle; Figure 7 This is a cross-sectional structural diagram of the sludge collection container of the present invention; Figure 8 This is a schematic diagram of the sludge collection container of the present invention without the filter ball.

[0016] Explanation of reference numerals in the attached figures 1. Housing; 11. Lower oil chamber; 12. Upper oil chamber; 13. Mounting chamber; 14. Flow chamber; 15. First partition; 16. Second partition; 161. Channel opening; 162. Horizontal through hole; 17. First filter plate; 170. Support plate; 171. Oil passage hole; 18. Inclined guide section; 19. Vertical guide section; 110. Limiting slide; 3. Oil tank; 4. Sludge collection container; 41. Second filter plate; 42. First magnetic suction component; 43. Connecting bracket; 44. Threaded sleeve; 5. Filter ball; 6. Circulation pipeline; 7. Shifting drive mechanism; 71. Oil cylinder; 72. Transmission rod; 73. Second magnetic suction component; 8. Maintenance vertical pipe; 81. Maintenance cover; 811. Lifting screw; 9. Vertical working channel; 10. Sealing protective cover. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. Example

[0018] like Figures 1 to 8 As shown, this embodiment provides an energy-saving oil-immersed power transformer, which includes a housing 1, a core winding assembly (the internal coils and core structure are not shown in detail in the figure, only the installation area is shown), and an oil conservator 3. The housing 1 is a sealed metal shell filled with transformer oil. The inner cavity of the housing 1 is divided into a lower oil cavity 11 located below and an upper oil cavity 12 located above by a first partition 15. The first partition 15 is not a single flat plate, but a combination with a bent structure. The upper oil cavity 12 is further divided by a second partition 16 into a mounting cavity 13 on the right and a flow cavity 14 on the left.

[0019] The iron core winding assembly is fixedly installed in the mounting cavity 13, with its bottom suspended or supported by a bracket, leaving space between the bottom surface of the iron core winding assembly and the first partition 15 for oil flow and impurity settling. The oil conservator 3 is located on the outside of the tank 1, above the exterior, and is used to contain the oil volume expansion caused by changes in oil temperature. The lower oil chamber 11 is connected to the oil conservator 3 through an external pipe, forming a conventional oil pillow breathing circuit.

[0020] like Figure 2 , Figure 3 and Figure 4As shown, the first partition 15 is integrally formed by a guide inclined section 18, a guide vertical section 19, and a horizontal section connected in sequence. The first filter plate 17 is located directly below the mounting cavity 13 and is horizontally positioned. The first filter plate 17 has through holes or can be made of porous material, and at least one open-top sludge collection container 4 is placed on its surface. In this embodiment, multiple sludge collection containers 4 arranged side-by-side are used as an example for explanation.

[0021] The sludge collection container 4 has a rectangular shell (see...). Figure 7 , Figure 8 The bottom wall of the filter is constructed as a second filter plate 41. The inside of the sludge collection container 4 is filled with multiple layers of filter balls 5. The filter balls 5 within the same layer have the same diameter, while the diameter of the multiple layers of filter balls 5 is distributed in a gradient increasing from bottom to top. For example, the bottom layer consists of smaller, finer filter balls, the middle layer consists of medium-diameter filter balls, and the top layer consists of larger, coarser filter balls. This structure achieves gradient filtration; the larger balls in the upper layer intercept large particles or fibrous flocs, while the smaller balls in the lower layer finely filter out tiny metal particles and carbon black, effectively avoiding the clogging defects of single-pore size filters and ensuring smooth oil flow.

[0022] As a preferred embodiment, the mesh size of the second filter plate 41 is smaller than the diameter of the bottommost filter ball 5 to prevent the filter ball 5 from leaking out from the bottom of the sludge collection container 4 into the lower oil cavity 11. To guide impurities smoothly into the sludge collection container 4, the guide inclined section 18 is located to the upper right of the first filter plate 17, and its downstream end (i.e., the lower left end) extends to the upper oblique side of the first filter plate 17. The top opening of the sludge collection container 4 is directly below the downstream side of the guide inclined section 18. When impurities generated by the iron core winding assembly fall with the oil flow or slide down from the side wall of the mounting cavity 13, they will slide into the sludge collection container 4 along the guide inclined section 18, achieving in-situ collection of impurities.

[0023] The vertical guide section 19 connects the lower left end of the inclined guide section 18 to the right end of the first filter plate 17. A certain distance is maintained between the vertical guide section 19 and the inner right wall of the housing 1, forming a vertical limiting slide 110. The sludge collection container 4 is slidably installed within the limiting slide 110, ensuring the stability of its positioning on the first filter plate 17 during daily operation and providing a guiding basis for subsequent online replacement operations.

[0024] In order to achieve maintenance or replacement of the sludge collection container 4 without shutting down the system, this embodiment further includes a circulation pipeline 6 and a displacement drive mechanism 7.

[0025] like Figure 2 , Figure 5 and Figure 6As shown, the circulation pipeline 6 is vertically installed outside the housing 1 or in an internal partition, with its lower end connected to the bottom of the flow chamber 14 and its upper end connected to a specific interface of the oil tank 3. A maintenance riser 8 is also connected to the oil tank 3. The maintenance riser 8 extends directly above the circulation pipeline 6, and its top end is equipped with a removable maintenance cover 81 (usually connected via a flange seal). Specifically, the first partition 15 located at the bottom of the flow chamber 14 is part of a support plate 170 (coplanar with or integral with the first filter plate 17), and an oil passage hole 171 is provided on the support plate 170. Thus, the oil in the lower oil chamber 11 can sequentially pass through the oil passage hole 171, the flow chamber 14, and the circulation pipeline 6 into the oil tank 3. Geometrically, the lower oil chamber 11, the oil passage hole 171, the flow chamber 14, the circulation pipeline 6, the oil tank 3, and the maintenance riser 8 together form a straight vertical working channel 9 in the vertical projection direction. The second partition 16 has a channel opening 161 at one end (i.e., the lower end) near the first filter plate 17. The width of the channel opening 161 is adapted to the thickness of the sludge collection container 4.

[0026] The specific structure of the displacement drive mechanism 7 is as follows: It includes a cylinder 71 (such as a hydraulic cylinder, pneumatic cylinder, or electric push rod) fixed to the inner wall of the housing 1 (located on the side wall of the flow cavity 14 in this embodiment). To protect the cylinder 71 from transformer oil corrosion, a sealed protective cover 10 is welded to the inner wall of the housing 1. The cylinder 71 is installed inside the sealed protective cover 10, and its piston rod passes through the protective cover through a sealing ring and is connected to a transmission rod 72. A transverse through hole 162 is opened on the second partition 16, and the transmission rod 72 passes horizontally through the transverse through hole 162 and enters the limiting slide 110 area. A second magnetic suction member 73 is fixed to the end of the transmission rod 72.

[0027] like Figure 3 , Figure 7 As shown, each sludge collection container 4 has a first magnetic suction element 42 embedded on its left and right outer walls (i.e., the two opposite outer walls). In normal operation, the first magnetic suction element 42 on the right side of the sludge collection container 4 located on the first filter plate 17 is magnetically attracted to the second magnetic suction element 73 on the transmission rod 72. At the same time, one side wall (right side wall) of the sludge collection container 4 partially blocks the channel opening 161 to prevent impurities in the mounting cavity 13 from directly entering the flow cavity 14 without settling.

[0028] When it is necessary to clean or replace the saturated sludge collection container 4 after long-term use, the specific operating steps are as follows: Control the piston rod of the hydraulic cylinder 71 to retract. Through the transmission rod 72 and the magnetic connection (the attraction force between the first magnetic element 42 and the second magnetic element 73 is greater than the sliding friction force of the sludge collection container 4 within the limiting slide 110), pull the sludge collection container 4 horizontally to the left along the limiting slide 110. The sludge collection container 4 passes through the channel opening 161 into the flow chamber 14 and finally stops directly above the oil passage 171 on the support plate 170, that is, at the bottom end of the vertical working channel 9 (see...). Figure 5 , Figure 6 (As shown in the diagram). At this time, the sludge collection container 4 is temporarily detached from the filtration station of the first filter plate 17.

[0029] Close the relevant valves on the transformer (or use oil pressure balancing), and open the inspection cover 81 on top of the oil conservator 3. Remove the pre-prepared lifting screw 811. Figure 6 As shown, each sludge collection container 4 has a connecting bracket 43 welded to its top, and a threaded sleeve 44 is fixed on the bracket. After passing the lifting screw 811 through the maintenance riser 8, oil tank 3, circulation pipeline 6, and flow chamber 14, it is screwed into the threaded sleeve 44 at the top of the sludge collection container 4 to achieve a threaded connection. Pulling the lifting screw 811 upwards, since the vertical working channel 9 is an unobstructed vertical channel, the sludge collection container 4, along with its internal filter ball 5 and the trapped impurities, is smoothly lifted to the outside of the maintenance riser 8, completing the replacement.

[0030] The new sludge collection container 4 is placed upside down into the vertical working channel 9 and lowered onto the support plate 170. The lifting screw 811 is removed, and the inspection cover 81 is closed. Then, the piston rod of the control cylinder 71 extends, pushing the sludge collection container 4 through the channel opening 161 back to the working position on the first filter plate 17. Both the first magnetic suction component and the second magnetic suction component 73 are electromagnet structures.

[0031] The complex external filter pipelines and rotating scraping mechanism have been eliminated. The first partition 15 within the tank itself forms an integrated layout for dirt collection, flow guidance, and filtration, resulting in low manufacturing costs, no moving mechanical wear parts, and a long service life. Multiple layers of filter balls 5 with gradually varying diameters within the dirt collection container 4 create a three-dimensional deep filtration space, achieving an organic combination of coarse and fine filtration. Transformer oil flows through the gaps between the filter balls 5 under gravity and thermal convection, with impurities being trapped layer by layer. The mesh of the second filter plate 41 ensures unobstructed oil flow from the bottom, greatly extending the service life of a single filtration cycle, reducing maintenance frequency, and embodying the energy-saving and consumption-reducing design concept. Through the coordination of the limiting slide 110, the shifting drive mechanism 7, and the vertical operating channel 9, the dirt collection container 4 can be moved horizontally from the working position to the extraction position and vertically lifted out. The entire replacement process only requires operation at the top of the oil tank, without draining transformer oil or disassembling the tank, significantly shortening maintenance time and ensuring the continuity of power supply.

[0032] In addition, when transformer oil flows from top to bottom through the sludge collection container 4 under the action of gravity and thermal convection, the larger diameter filter balls 5 at the top first coarsely filter and intercept fibrous flocs and large particulate impurities, forming relatively loose pore channels; the smaller diameter filter balls 5 in the middle and lower parts then finely filter and intercept fine metal particles, carbon black and other impurities, thus constructing a gradient filtration matrix from coarse to fine in the vertical direction. When the transformer oil experiences reverse surging due to temperature fluctuations or system pressure changes (i.e., backflow from the lower oil chamber 11 to the inside of the sludge collection container 4), because the gaps between the lower filter balls 5 are dense and the pore size is small, the impurities trapped in the lower and middle filter balls 5 are physically blocked by the dense spheres and cannot escape upward with the reverse oil flow; while although the upper large diameter filter balls 5 have larger pores, the large particulate impurities trapped inside are too heavy due to their own weight and are embedded in the gaps between the balls, so the backflow disturbance is insufficient to make them cross the dense filter layer below and return to the oil circuit. In addition, the gradually increasing ball diameter gradient from bottom to top naturally forms a flow resistance distribution pattern of "large inlet and small outlet". During forward filtration, the oil flow resistance decreases from bottom to top, while during reverse flow, the resistance increases from bottom to top. This asymmetric flow resistance characteristic effectively inhibits the reverse migration of impurities under reverse flow conditions, ensuring that the captured impurities of various particle sizes remain stably trapped inside the sludge collection container 4.

[0033] Meanwhile, during the process of using the shift drive mechanism 7 to horizontally drag the sludge collection container 4 from the working position on the first filter plate 17 to the extraction position on the support plate 170, and during the operation of vertically lifting the sludge collection container 4 along the vertical working channel 9 by the lifting screw 811, the sludge collection container 4 is inevitably subjected to inertial forces such as horizontal acceleration, deceleration and vertical lifting vibration. Under these dynamic conditions, the multi-layer gradient filter ball structure exhibits a significant ability to retain impurities in situ: the lower layer of five smaller diameter filter balls, due to their dense contact points and tight packing, not only forms a strong physical encapsulation and embedding of fine impurities, but also the frictional self-locking effect between the balls gives this layer of filter balls high structural stability, making it less prone to relative rolling or loosening during movement, thus firmly locking the trapped metal particles and carbon black in the gaps of the dense ball layer; although the middle and upper layers of five filter balls have gradually increased diameter and more packing gaps, the flocculent and flaky impurities intercepted by the larger balls usually have a large surface area and irregular shape. Under oil immersion conditions, they will partially adhere to the surface of the filter ball five or entangle with each other to form flocs. In addition, the gravity self-tightening effect generated by the bottom-to-top ball diameter gradient (the upper large balls exert downward pressure on the lower small balls) further enhances the integrity and anti-disturbance ability of the entire filter media stack. Therefore, even if the sludge collection container 4 changes position or is subjected to external mechanical vibration during replacement, impurities remain constrained by the multi-layer filter balls 5 and will not re-suspend and re-enter the clear oil layer above the container due to shaking, nor will they escape into the tank 1 from the top opening. This characteristic not only ensures that the transformer oil itself is not subject to secondary contamination during replacement operations, but also makes the transfer and disposal of the used sludge collection container 4 safer and cleaner, effectively improving the environmental friendliness and ease of operation of online maintenance operations, and fully demonstrating the significant progress of this transformer in filtration and sludge collection reliability.

[0034] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. An energy-saving oil-immersed power transformer, comprising a housing (1), a core winding assembly, and an oil conservator (3), wherein the housing (1) is provided with a first partition (15) and a second partition (16), the first partition (15) dividing the inner cavity of the housing (1) into a lower oil cavity (11) and an upper oil cavity (12), the second partition (16) dividing the upper oil cavity (12) into an installation cavity (13) and a flow cavity (14), the core winding assembly being installed in the installation cavity (13), and the lower oil cavity (11) being connected to the oil conservator (3), characterized in that, The first partition (15) has at least a horizontal section, and the horizontal section located in the mounting cavity (13) is a first filter plate (17). The first filter plate (17) is provided with at least one top-open sludge collection container (4), which is located below the iron core winding assembly, and its bottom wall is constructed as a second filter plate (41). The sludge collection container (4) contains multiple layers of filter balls (5), with the same diameter of the filter balls (5) in the same layer, and the diameter of the multiple layers of filter balls (5) increasing from bottom to top.

2. The energy-saving oil-immersed power transformer according to claim 1, characterized in that, The mesh size of the second filter plate (41) is smaller than the diameter of the filter ball (5) located at the bottom.

3. The energy-saving oil-immersed power transformer according to claim 1, characterized in that, The first partition (15) also includes a flow guiding inclined section (18), the downstream end of which is located obliquely above the first filter plate (17), and the opening of the sludge collection container (4) is connected to the lower downstream side of the flow guiding inclined section (18).

4. The energy-saving oil-immersed power transformer according to claim 3, characterized in that, The first partition (15) further includes a vertical guide section (19), the inclined guide section (18), the vertical guide section (19) and the first filter plate (17) are connected in sequence, the vertical guide section (19) and the inner wall of the box (1) form a limiting slide (110), and the sludge collection container (4) is slidably disposed in the limiting slide (110).

5. The energy-saving oil-immersed power transformer according to claim 4, characterized in that, It also includes a circulation pipeline (6) and a displacement drive mechanism (7). The circulation pipeline (6) is vertically arranged, with one end connected to the flow cavity (14) and the other end connected to the oil tank (3). A maintenance vertical pipe (8) is also connected to the oil tank (3). The maintenance vertical pipe (8) is located in the extension direction of the circulation pipeline (6) and its end is provided with a detachable maintenance cover (81). The first partition (15) located at the bottom of the flow chamber (14) is partially constructed as a support plate (170). The support plate (170) has an oil passage hole (171). The lower oil chamber (11) passes through the oil passage hole (171), the flow chamber (14), the circulation pipeline (6), the oil tank (3), and the maintenance vertical pipe (8) to form a vertical working channel (9). The second partition (16) has a channel opening (161) at one end near the first filter plate (17), and the shifting drive mechanism (7) can drive the sludge collection container (4) to move along the limiting slide (110) to the bottom of the vertical working channel (9).

6. The energy-saving oil-immersed power transformer according to claim 5, characterized in that, The displacement drive mechanism (7) includes a hydraulic cylinder (71); The sludge collection container (4) is a rectangular shell, and there are multiple of them. Each of the two opposite outer side walls is provided with a first magnetic suction element (42). A transverse through hole (162) is provided on the second partition (16). The piston rod of the oil cylinder (71) is connected to a transmission rod (72). The transmission rod (72) passes through the transverse through hole (162) and is fixed with a second magnetic attractor (73). The second magnetic attractor (73) is used to magnetically connect with the first magnetic attractor (42).

7. The energy-saving oil-immersed power transformer according to claim 6, characterized in that, One side wall portion of the sludge collection container (4) is located within the channel opening (161) to conceal the channel opening (161).

8. The energy-saving oil-immersed power transformer according to claim 6, characterized in that, The inspection cover (81) has a threaded hole and a lifting screw (811) is screwed on it. Each of the sludge collection containers (4) is fixedly provided with a connecting bracket (43). A threaded sleeve (44) is fixedly provided on the connecting bracket (43). The lifting screw (811) can be threadedly connected to the threaded sleeve (44).

9. The energy-saving oil-immersed power transformer according to claim 6, characterized in that, It also includes a sealing protective cover (10), which is fixed to the inner wall of the box (1). The oil cylinder (71) is installed inside the sealing protective cover (10), and its piston rod passes through the sealing protective cover (10) and is connected to the transmission rod (72).

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