Efficient heat dissipation oil-immersed power transformer

Abstract

The invention discloses an efficient heat dissipation oil-immersed power transformer, and relates to the technical field of power transformers. The self-adaptive transformer comprises a box body, a winding, an oil conservator and a self-adaptive heat dissipation assembly, a slidable partition plate is arranged in the box body and divides the interior into an upper cavity and a lower cavity, an elastic cleaning brush is arranged in an annular hole in the middle of the partition plate, and the surface of a winding can be automatically cleaned when the transformer runs; a spiral radiating pipe is integrated in the oil conservator, so that hot oil can be primarily cooled; a self-adaptive heat dissipation assembly composed of fixed fins, movable fins and a thermosensitive driving element is arranged on the outer wall of the box body, and the thermosensitive driving element drives the movable fins to stretch out and draw back according to oil temperature changes to change the heat dissipation area. An intelligent control system is further arranged, and accurate and active regulation and control of the heat dissipation capacity are achieved through linkage of a temperature sensor, a controller, an electric adjusting valve and a heat dissipation fan. The transformer is simple and reliable in structure, high in heat dissipation efficiency, rapid in response and capable of effectively guaranteeing stable operation of the transformer under complex working conditions.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power transformers, and particularly relates to an oil-immersed power transformer with high-efficiency heat dissipation. BACKGROUND

[0002] The oil-immersed power transformer is a key equipment in the power grid system. When the transformer is running, the heat generated by the winding is conducted to the transformer tank through the insulating oil, and finally dissipated to the air through the heat dissipation fins on the surface of the tank. The traditional oil-immersed transformer adopts fixed heat dissipation fins and relies on the natural convection of the insulating oil for heat dissipation. The efficiency is low, and especially when the load suddenly increases or the ambient temperature is high, the temperature rise is prone to be too high, which affects the insulation life and operation safety of the transformer.

[0003] To solve the above problems, some improvement schemes are proposed in the prior art. For example, patent CN117877863B discloses an oil-immersed power transformer with high-efficiency heat dissipation, which comprises a tank and an oil pillow. The tank is provided with a winding. The tank is provided with a partition plate. The partition plate divides the tank into an upper cavity and a lower cavity. The oil pillow is in communication with the upper cavity. The outer periphery of the tank is provided with a plurality of heat dissipation mechanisms. The heat dissipation mechanism comprises fixed fins and movable fins. The movable fins are movably arranged in the fixed fins. An oil storage cavity is formed between the fixed fins and the movable fins. The oil storage cavity is in communication with the lower cavity. The heat dissipation mechanism further comprises a driving assembly for driving the movable fins to move in the fixed fins. The present application forms a set of heat dissipation system between the upper cavity and the oil pillow, and forms another set of heat dissipation system between the lower cavity and the heat dissipation mechanism. The two sets of heat dissipation systems alternately circulate to cool and dissipate heat for the winding, which can greatly improve the heat dissipation performance of the power transformer.

[0004] Although the scheme has certain effect, it still has obvious deficiencies. First, the driving mechanism has a complex structure, including a piston cylinder, a connecting rod, a rotating wheel and other precise components, which has high manufacturing cost and poor reliability in long-term operation in an oil temperature changing environment, and is inconvenient for fault maintenance. Second, the driving relies on the gasification speed of the liquid, and the response is delayed, so that rapid and accurate temperature regulation cannot be realized. Third, the scheme is completely passive response, lacks active intelligent control ability, and cannot adapt to changes in complex working conditions.

[0005] Therefore, there is an urgent need in the field for a high-efficiency heat dissipation transformer with simpler structure, faster response and more intelligent control. SUMMARY

[0006] The application aims to provide an oil-immersed power transformer with high-efficiency heat dissipation, which solves the problems of complex heat dissipation structure, delayed response and lack of intelligent active control ability of the existing oil-immersed power transformer.

[0007] To solve the above technical problems, the present application is realized by the following technical solutions: The present application is a kind of oil-immersed power transformer with high heat dissipation, comprising a box, a winding arranged in the box, a partition plate arranged in the box along the vertical direction, the partition plate is sealed with the inner wall of the box, the inner part of the box is divided into an upper cavity and a lower cavity which are independent of each other, and a ring-shaped hole adapted to the winding is arranged in the middle of the partition plate, an elastic cleaning brush is arranged on the inner wall of the ring-shaped hole, and the elastic cleaning brush is attached to the outer peripheral wall of the winding. A support frame is fixed on one side of the upper surface of the box, an oil pillow is fixed on the upper end of the support frame, the oil pillow is communicated with the upper cavity through an oil pipe, a spiral heat dissipation pipe is arranged in the oil pillow, and the two ends of the spiral heat dissipation pipe extend to the outside of the oil pillow and form a cooling liquid inlet and a cooling liquid outlet. A discharge oil main pipe and an intake oil main pipe are arranged on the outer wall of the lower cavity, the discharge oil main pipe and the intake oil main pipe are communicated with the self-adaptive heat dissipation assembly through a plurality of branch oil pipes, and a one-way valve B is arranged on the discharge oil main pipe and the intake oil main pipe. Self-adaptive heat dissipation assemblies are arranged on the opposite surfaces of the box, each self-adaptive heat dissipation assembly comprises a plurality of fixed fins fixed on the outer wall of the box, a movable fin slidingly arranged in the fixed fin, and a heat-sensitive driving element driving the movable fin to extend and retract, and the phase transition temperature of the heat-sensitive driving element is adapted to the normal working temperature threshold of the transformer; an oil storage channel communicated with the branch oil pipe is arranged in the fixed fin, an extendable auxiliary heat dissipation cavity is formed between the fixed fin and the movable fin, and the auxiliary heat dissipation cavity is communicated with the oil storage channel.

[0008] In one embodiment, the oil pipe is provided with two oil pipes, the upper ends of the two oil pipes are respectively mounted on the outer wall of the lower part of the oil pillow on both sides, the lower ends of the two oil pipes are respectively communicated with the left part and the right part of the upper cavity, and one-way valves A are mounted on the side surfaces of the two oil pipes.

[0009] In one embodiment, an oil inlet is arranged in the middle of the side surface of the oil pillow, a plurality of heat dissipation fins are integrated on the outer wall of the oil pillow, and an oil temperature monitoring module is arranged in the oil pillow.

[0010] In one embodiment, the heat-sensitive driving element is a shape memory alloy spring made of Ti-Ni-Cu ternary memory alloy, the phase transition temperature of the shape memory alloy spring is set to 65-70℃, the shape memory alloy spring is in a contracted state at normal temperature and in an elongated state above the phase transition temperature, the heat-sensitive driving element is arranged between the fixed fin and the movable fin, the state of the heat-sensitive driving element changes with the temperature change of the insulating oil in the oil storage channel, and the heat-sensitive driving element directly drives the movable fin to extend and retract relative to the fixed fin.

[0011] In one of the embodiments, the outer periphery of the partition plate is sleeved with an elastic sealing ring, the elastic sealing ring is in interference fit with the inner wall of the tank, and the elastic sealing ring is made of oil-resistant nitrile rubber.

[0012] In one of the embodiments, the elastic cleaning brush is a nylon brush, the length of the bristles of the nylon brush is adapted to the radial thickness of the winding, and the surface of the bristles is coated with a wear-resistant ceramic coating.

[0013] In one of the embodiments, a plurality of the fixed fins are arranged in parallel and at intervals, ventilation gaps are formed between adjacent fixed fins, and the side walls of the fixed fins are welded and fixed to the outer wall of the tank.

[0014] An intelligent control system for an oil-immersed power transformer with high-efficiency heat dissipation, comprising: A temperature sensor arranged in the lower cavity and / or the oil storage channel for detecting the temperature of the insulating oil; A controller connected in signal with the temperature sensor; An electric regulating valve arranged on the front section of the oil outlet pipe and electrically connected with the controller; The controller is configured to control the opening degree of the electric regulating valve according to the received temperature signal.

[0015] In one of the embodiments, an auxiliary cooling fan is further included, the auxiliary cooling fan is installed outside the transformer tank and electrically connected with the controller, and the start-stop and rotation speed of the auxiliary cooling fan are controlled by the controller according to the temperature signal.

[0016] In one of the embodiments, the controller is configured to execute the following control logic: When the detected temperature of the insulating oil is lower than a first threshold T1, the electric regulating valve is kept closed, and the auxiliary cooling fan is turned off; When the detected temperature of the insulating oil reaches the first threshold T1 and is lower than a second threshold T2, the electric regulating valve is controlled to open to a first opening degree, and the auxiliary cooling fan is started to run at a low speed; When the detected temperature of the insulating oil reaches or exceeds the second threshold T2, the electric regulating valve is controlled to open to a second opening degree, and the auxiliary cooling fan is controlled to run at a high speed; The first threshold T1 is lower than the second threshold T2, and the first threshold T1 is set to be close to or slightly higher than the starting point of the phase transition temperature of the thermosensitive driving element.

[0017] The present application has the following beneficial effects: I. The heat dissipation efficiency is improved in a step-by-step manner, and the complex working conditions are adapted Three-level heat dissipation system covers the entire temperature range: from the "primary cooling" of the spiral heat dissipation pipe in the oil reservoir, to the "dynamic enhanced heat dissipation" of the adaptive heat dissipation assembly, to the "active auxiliary heat dissipation" triggered by the intelligent control system, forming a progressive heat dissipation chain. For example, the hot oil in the oil reservoir is first rapidly heat-exchanged with the cooling liquid through the spiral pipe, and then returns to the box after preliminary cooling; when the oil temperature rises to the phase change threshold, the shape memory alloy drives the movable fins to extend, which can increase the heat dissipation area; under high temperature conditions, the electric regulating valve is fully opened + the high-speed heat dissipation fan is started, further breaking through the heat dissipation bottleneck, and compared with the traditional fixed heat sink, the overall heat dissipation efficiency is greatly improved, effectively solving the temperature rise problem under sudden load increase or high temperature environment.

[0018] Instant response with heat-sensitive drive, no delay adjustment: Ti-Ni-Cu ternary memory alloy spring is used as the heat-sensitive drive element, and the phase change temperature is accurately matched with the normal working threshold of the transformer (65-70℃). Without external power, the movable fins can be driven to extend or retract only by oil temperature change. Compared with the traditional passive heat dissipation scheme relying on connecting rod mechanism, the response speed is greatly improved, avoiding local overheating caused by driving delay and ensuring the temperature stability of the transformer under load fluctuation.

[0019] II. Simplified structure and high reliability, reducing the whole life cycle cost Simple driving structure, reducing failure risk: Abandoning the complex piston cylinder, rotating wheel and other precision components in the prior art, the adaptive heat dissipation assembly only realizes the function through "fixed fins + movable fins + memory alloy spring", reducing the number of components, and the memory alloy material is oil-resistant and aging-resistant, greatly reducing the long-term operation failure rate; At the same time, the oil circuit system composed of the oil outlet pipe, branch oil pipe and one-way valve B has compact structure and anti-backflow function, avoiding oil leakage or circulation disorder, further improving the operation reliability.

[0020] Wear-resistant design prolongs the service life of components: The oil-resistant butadiene rubber sealing ring is used in the partition plate, which has excellent sealing performance and is resistant to oil corrosion, and the service life can be greatly improved; The elastic cleaning brush is made of nylon material and coated with wear-resistant ceramic coating, which not only ensures the cleaning effect on the surface of the winding, but also avoids the rapid wear of the brush, so that it does not need to be replaced frequently, reducing the maintenance frequency and cost.

[0021] III. Intelligent active regulation, realizing fine energy consumption management Gradient control strategy, taking into account heat dissipation and energy saving: the controller realizes three-level regulation according to temperature thresholds (T1 approaches the phase change temperature, and T2 is the safety warning temperature): at low temperature, only passive heat dissipation is relied on, the electric valve and fan are closed, and the energy consumption is reduced to the minimum; at medium temperature, part of the oil circuit + low-speed fan is started, balancing the heat dissipation demand and energy consumption; at high temperature, full load operation is realized, and the safety of the equipment is prioritized. Compared with the traditional scheme of full-load heat dissipation, the auxiliary energy consumption can be greatly reduced, which meets the development trend of green power equipment.

[0022] Multi-dimensional monitoring ensures safe operation: the oil pillow is provided with an oil temperature monitoring module, temperature sensors are arranged in the lower cavity and the oil storage channel, real-time temperature data of key parts are collected and fed back to the controller, and the temperature is monitored in the whole domain; once the temperature is abnormal, the controller can quickly adjust the heat dissipation strategy, even trigger an alarm, provide data support for transformer fault early warning and operation and maintenance, and reduce the risk of insulation aging or burning caused by overheating.

[0023] Four, additional cleaning function, indirectly strengthens the stability of heat dissipation The separation plate can drive the elastic cleaning brush on the inner wall of the annular hole to continuously adhere to the winding surface due to the micro-motion caused by the vibration or thermal expansion and contraction of the transformer, and automatically remove dust, oil stains and other impurities on the winding. This design can avoid the decrease of heat conduction efficiency caused by impurity accumulation without additional power, indirectly ensure the long-term stable heat dissipation of the winding, prolong the service life of the insulation layer, and further improve the overall operation stability of the transformer.

[0024] In summary, through the synergistic design of "passive heat dissipation optimization + self-adaptive adjustment + intelligent active control", the core problems of low heat dissipation efficiency and slow response of traditional oil-immersed transformers are solved, and the structure is simplified, the energy consumption is reduced, and the maintenance is convenient. The oil-immersed power transformer can be widely used in different loads and different environmental temperatures in the power grid system, and has high practical value and wide application prospect.

[0025] Of course, any product implementing the present application does not necessarily need to achieve all the advantages described above. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0027] Figure 1 is a structural schematic view in a low-temperature state, in which the movable fins are in a retracted state; Figure 2 is a front view of Figure 1 ; Figure 3 for Figure 2 Sectional view of AA in the middle; Figure 4 This is a schematic diagram of the structure under high temperature conditions, in which the movable fins are in the extended state; Figure 5 for Figure 4 The main view; Figure 6 for Figure 5 BB floor plan; Figure 7 This is a schematic diagram of the structure of the present invention without the fixing frame and auxiliary cooling fan; Figure 8 This is a schematic diagram of a portion of the internal three-dimensional structure of the present invention.

[0028] The attached diagram lists the components represented by each number as follows: 1. Housing; 2. Winding; 3. Upper cavity; 4. Lower cavity; 5. Divider plate; 501. Annular hole; 502. Flexible cleaning brush; 6. Support frame; 7. Oil conservator; 8. Oil pipe; 9. One-way valve A; 10. Spiral heat dissipation pipe; 11. Coolant inlet; 12. Coolant outlet; 13. Oil inlet; 14. Heat dissipation fins; 15. Adaptive heat dissipation assembly; 16. Fixed fins; 17. Movable fins; 18. Thermosensitive drive element; 19. Main oil outlet pipe; 20. Branch oil outlet pipe; 21. Main oil inlet pipe; 22. Oil storage channel; 23. Auxiliary heat dissipation cavity; 24. Electric regulating valve; 25. Controller; 26. Auxiliary cooling fan; 27. Fixture; 28. One-way valve B. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] In the description of this invention, it should be understood that the terms "upper," "middle," "outer," "inner," etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0031] In the description of the present application, it should be noted that unless otherwise expressly specified and limited, the terms "mounting", "provided with", "connected", and the like, should be interpreted broadly, for example, "connected" can be fixedly connected, or detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, or can be connected internally between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] Embodiment one: Please refer to Figures 1-8 As shown in the drawings, the present application is a high-efficiency heat dissipation oil-immersed power transformer, comprising a box body 1, a winding 2 arranged in the box body 1, a partition plate 5 arranged in the box body 1 along the vertical direction, the partition plate 5 is sealingly matched with the inner wall of the box body 1, the inside of the box body 1 is divided into an upper cavity 3 and a lower cavity 4 which are independent of each other, and a ring-shaped hole 501 adapted to the winding 2 is formed in the middle of the partition plate 5, an elastic cleaning brush 502 is arranged on the inner wall of the ring-shaped hole 501, and the elastic cleaning brush 502 is attached to the outer peripheral wall of the winding 2; A support frame 6 is fixed on one side of the upper surface of the box body 1, an oil pillow 7 is fixed on the upper end of the support frame 6, the oil pillow 7 is communicated with the upper cavity 3 through an oil pipe 8, a spiral heat dissipation pipe 10 is arranged in the oil pillow 7, and the two ends of the spiral heat dissipation pipe 10 extend to the outside of the oil pillow 7 and form a cooling liquid inlet 11 and a cooling liquid outlet 12, respectively; A discharge oil main pipe 19 and an intake oil main pipe 21 are arranged on the outer wall of the lower cavity 4, the discharge oil main pipe 19 and the intake oil main pipe 21 are both communicated with the self-adaptive heat dissipation assembly 15 through a plurality of branch oil pipes 20, and a one-way valve B 28 is arranged on the discharge oil main pipe 19 and the intake oil main pipe 21, and the one-way valve 28 is used to prevent the backflow of oil; The self-adaptive heat dissipation assembly 15 is arranged on the opposite surfaces of the box body 1, the self-adaptive heat dissipation assembly 15 comprises a plurality of fixed fins 16 fixed on the outer wall of the box body 1, a movable fin 17 slidingly arranged in the fixed fin 16, and a heat-sensitive driving element 18 driving the movable fin 17 to extend and retract, and the phase change temperature of the heat-sensitive driving element 18 is adapted to the normal working temperature threshold of the transformer; an oil storage channel 22 communicated with the branch oil pipe 20 is formed in the fixed fin 16, and an auxiliary heat dissipation cavity 23 formed between the fixed fin 16 and the movable fin 17 is in communication with the oil storage channel 22.

[0033] Further, the oil pipe 8 is provided with two oil pipes, the upper ends of which are respectively mounted on the outer wall of the lower part of the oil pillow 7 on both sides, and the lower ends are respectively communicated with the left part and the right part of the upper cavity 3, and the two oil pipes 8 are provided with a one-way valve A 9 on the side surface.

[0034] Furthermore, an oil inlet 13 is provided in the middle of the side of the oil conservator 7, several heat dissipation fins 14 are integrated on the outer wall of the oil conservator 7, and an oil temperature monitoring module is provided inside the oil conservator 7.

[0035] Furthermore, the thermal drive element 18 is a shape memory alloy spring made of Ti-Ni-Cu ternary shape memory alloy, with its phase transition temperature set at 65-70℃. This range matches the normal operating temperature threshold of the transformer, preventing false triggering and ensuring timely response when the oil temperature rises. The shape memory alloy spring is in a contracted state at room temperature and in an extended state above the phase transition temperature. The thermal drive element 18 is positioned between the fixed fin 16 and the movable fin 17, and its state changes with the temperature of the insulating oil in the oil storage channel 22, directly driving the movable fin 17 to extend and retract relative to the fixed fin 16.

[0036] Furthermore, an elastic sealing ring is fitted around the outer periphery of the partition plate 5. The elastic sealing ring is interference-fitted with the inner wall of the box 1, and the elastic sealing ring is made of oil-resistant nitrile rubber.

[0037] Furthermore, the flexible cleaning brush 502 is a nylon brush with bristle length adapted to the radial thickness of the winding 2. The surface of the bristles of the flexible cleaning brush 502 is coated with an alumina wear-resistant ceramic coating, which can effectively extend the service life of the bristles.

[0038] Furthermore, several fixed fins 16 are arranged in parallel at intervals, and ventilation gaps are formed between adjacent fixed fins 16. The sidewalls of the fixed fins 16 are welded and fixed to the outer wall of the housing 1.

[0039] An intelligent control system for an oil-immersed power transformer with high-efficiency heat dissipation includes: A temperature sensor, located in the lower cavity 4 and / or the oil storage channel 22, is used to detect the temperature of the insulating oil. Controller 25 is connected to the temperature sensor signal; The electric regulating valve 24 is installed on the oil line at the front end of the main oil outlet pipe 19 and is electrically connected to the controller 25; The controller 25 is configured to control the opening degree of the electric regulating valve 24 according to the received temperature signal.

[0040] Furthermore, it also includes an auxiliary cooling fan 26, which is installed outside the transformer housing 1 and electrically connected to the controller 25. The controller 25 controls its start / stop and speed according to the temperature signal.

[0041] Furthermore, controller 25 is configured to execute the following control logic: When the detected insulating oil temperature is lower than the first threshold T1, the electric regulating valve 24 is kept closed and the auxiliary cooling fan 26 is turned off. When the detected insulating oil temperature reaches the first threshold T1 and is lower than the second threshold T2, the electric regulating valve 24 is controlled to open to the first opening degree, and the auxiliary cooling fan 26 is started to run at low speed. When the detected insulating oil temperature reaches or exceeds the second threshold T2, the electric regulating valve 24 is opened to the second opening degree, and the auxiliary cooling fan 26 is controlled to run at high speed. The first threshold T1 is lower than the second threshold T2, and the first threshold T1 is set to be close to or slightly higher than the phase change temperature starting point of the thermal drive element 18.

[0042] Example 2: like Figures 1 to 8 As shown, the core of the oil-immersed power transformer with high-efficiency heat dissipation described in this invention lies in its innovative heat dissipation structure and intelligent control system.

[0043] Transformer main structure: The housing 1 houses the windings 2. The key feature is the addition of a vertically sliding partition plate 5 along the inner wall of the housing. This partition plate 5 is sealed to the inner wall of the housing 1 by an oil-resistant nitrile rubber sealing ring, thus dividing the interior of the housing into an independent upper cavity 3 and a lower cavity 4. The partition plate 5 has an annular hole 501 in its center for the windings 2 to pass through. A nylon elastic cleaning brush 502 on the inner wall of the hole remains in contact with the outer wall of the windings. When the transformer vibrates slightly due to electromagnetic force or thermal expansion and contraction, the partition plate 5 moves slightly, causing the cleaning brush 502 to continuously clean the surface of the windings.

[0044] Oil circuit and primary heat dissipation: The oil conservator 7 is fixed above the housing 1 by a support frame 6 and is connected to the upper cavity 3 through two oil pipes 8 with one-way valves A9. The oil conservator 7 integrates a spiral heat dissipation pipe 10, which allows for initial cooling of the hot oil inside the conservator via externally circulating cooling water or coolant. The heat dissipation fins 14 on the outer wall of the oil conservator 7 further enhance heat dissipation.

[0045] Adaptive heat dissipation assembly: This assembly is the main heat dissipation part of the invention. Fixed fins 16 are welded to the outer wall of the housing 1, and an oil storage channel 22 is opened inside them. Movable fins 17 slide inside the fixed fins 16. A thermally sensitive driving element 18 (shape memory alloy spring) is placed between them. When the transformer load increases, the oil temperature in the lower cavity 4 rises, and hot oil enters the oil storage channel 22 through the main oil outlet pipe 19 and the branch oil outlet pipe 20, heating the shape memory alloy spring. When the oil temperature exceeds its phase transition point (e.g., 65°C), the spring extends, pushing the movable fins 17 out, increasing the heat dissipation area. At the same time, hot oil flows in the auxiliary heat dissipation cavity 23, efficiently dissipating heat through the expanded fin assembly. After cooling, the oil flows back to the lower cavity 4 through the main oil inlet pipe 21. One-way valves B on each main pipe ensure one-way circulation of the oil flow.

[0046] Intelligent control system: This system further improves the accuracy of heat dissipation control. The temperature sensor installed in the lower cavity 4 monitors the oil temperature in real time and transmits the signal to the controller 25 (such as a PLC or a dedicated control chip). The controller 25 controls the opening degree of the electric control valve 24 and the rotational speed of the auxiliary cooling fan 26 according to the preset temperature thresholds (such as T1 = 65°C, T2 = 75°C). At low temperatures, the system mainly relies on the passive heat dissipation of the oil conservator and the adaptive components; at medium temperatures, the oil circuit is opened and the low-speed fan is started; at high temperatures, the oil circuit is fully opened and the high-speed fan is started, forming a gradient and intelligent heat dissipation strategy to ensure that the transformer always operates in the optimal temperature range.

[0047] Embodiment 3: The working principle of the high-efficiency heat dissipation oil-immersed power transformer of the present invention is as follows: 1. Hot oil circulation and primary cooling When the transformer operates, the winding generates heat, causing the temperature of the insulating oil to rise.

[0048] The hot oil rises to the oil conservator 7 and exchanges heat with the external cooling medium through the spiral heat dissipation pipe 10 to achieve primary cooling.

[0049] The heat dissipation fins 14 outside the oil conservator further enhance the heat dissipation effect.

[0050] 2. Operation of the adaptive heat dissipation component When the oil temperature rises, the hot oil flows into the oil storage channel 22 in the fixed fins 16 through the outlet oil guiding main pipe 19 and the branch oil guiding pipes 20.

[0051] The thermally sensitive driving element 18 (shape memory alloy spring) expands when heated, pushing the movable fins 17 out to increase the heat dissipation area.

[0052] After the oil temperature drops, the spring contracts, the movable fins retract, and the cooled hot oil flows into the lower cavity 4 through the inlet oil guiding main pipe 21 and the branch oil guiding pipes 20, realizing automatic adjustment of the heat dissipation area.

[0053] 3. Response of the intelligent control system The temperature sensor monitors the oil temperature in real time and transmits the signal to the controller 25.

[0054] The intelligent control system controls in three levels according to the oil temperature: Low temperature stage (oil temperature < T1, such as 65°C): The electric control valve is closed, the cooling fan stops rotating, and mainly relies on the passive heat dissipation of the oil conservator and the adaptive components.

[0055] Medium temperature stage (T1 ≤ oil temperature < T2, such as 65°C - 75°C): The electric control valve is opened to the first opening degree, the cooling fan runs at low speed to enhance heat dissipation.

[0056] High temperature stage (oil temperature ≥ T2, such as ≥ 75℃): the electric regulating valve is fully open and the cooling fan runs at high speed to maximize heat dissipation efficiency.

[0057] The controller 25 achieves precise and proactive heat dissipation control based on a preset temperature threshold.

[0058] 4. Cleaning function During transformer operation, the adaptive heat dissipation component 15 and the partition plate 5 slide along the winding 2, driving the elastic cleaning brush 502 to automatically clean the surface of the winding 2, preventing dust accumulation from affecting heat dissipation.

[0059] In the description of this specification, references to terms such as "an embodiment," "example," and "specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high-efficiency heat dissipation oil-immersed power transformer, comprising a housing (1) and windings (2) disposed within the housing (1), characterized in that: A partition plate (5) is slidably arranged in the vertical direction inside the housing (1). The partition plate (5) is sealed to the inner wall of the housing (1) to divide the interior of the housing (1) into an independent upper cavity (3) and a lower cavity (4). An annular hole (501) adapted to the winding (2) is opened in the middle of the partition plate (5). An elastic cleaning brush (502) is provided on the inner wall of the annular hole (501). The elastic cleaning brush (502) is attached to the outer peripheral wall of the winding (2). A support frame (6) is fixed on one side of the upper surface of the housing (1). An oil conservator (7) is fixed at the upper end of the support frame (6). The oil conservator (7) is connected to the upper cavity (3) through an oil pipe (8). A spiral heat dissipation pipe (10) is provided inside the oil conservator (7). The two ends of the spiral heat dissipation pipe (10) extend to the outside of the oil conservator (7) and form a coolant inlet (11) and a coolant outlet (12). The lower cavity (4) has an oil outlet main pipe (19) and an oil inlet main pipe (21) on its outer wall. The oil outlet main pipe (19) and the oil inlet main pipe (21) are connected to the adaptive heat dissipation component (15) through several branch oil pipes (20). Both the oil outlet main pipe (19) and the oil inlet main pipe (21) are equipped with a one-way valve B (28). The housing (1) is provided with an adaptive heat dissipation assembly (15) on two opposite surfaces. The adaptive heat dissipation assembly (15) includes several fixed fins (16) fixed to the outer wall of the housing (1), movable fins (17) slidably disposed in the fixed fins (16), and a thermal drive element (18) for driving the movable fins (17) to extend and retract. The phase change temperature of the thermal drive element (18) is adapted to the normal operating temperature threshold of the transformer. An oil storage channel (22) communicating with the branch oil pipe (20) is opened inside the fixed fins (16). An extendable auxiliary heat dissipation cavity (23) is formed between the fixed fins (16) and the movable fins (17). The auxiliary heat dissipation cavity (23) is communicating with the oil storage channel (22).

2. The oil-immersed power transformer with high-efficiency heat dissipation according to claim 1, characterized in that, Two oil pipes (8) are provided. The upper ends are respectively installed on the lower outer wall of the oil pillow (7) and the lower ends are respectively connected to the left and right parts of the upper cavity (3). One-way valves A (9) are installed on the periphery of the two oil pipes (8).

3. The oil-immersed power transformer with high-efficiency heat dissipation according to claim 2, characterized in that, The oil conservator (7) has an oil inlet (13) in the middle of its periphery, and the outer wall of the oil conservator (7) is equipped with several heat dissipation fins (14). The oil conservator (7) is also equipped with an oil temperature monitoring module inside.

4. The oil-immersed power transformer with high-efficiency heat dissipation according to claim 3, characterized in that, The thermal drive element (18) is a shape memory alloy spring made of Ti-Ni-Cu ternary shape memory alloy. Its phase change temperature is set to 65-70℃. The shape memory alloy spring is in a contracted state at room temperature and in an extended state above the phase change temperature. The thermal drive element (18) is located between the fixed fin (16) and the movable fin (17). Its state changes with the temperature of the insulating oil in the oil storage channel (22) and directly drives the movable fin (17) to extend and retract relative to the fixed fin (16).

5. The oil-immersed power transformer with high-efficiency heat dissipation according to claim 4, characterized in that, The outer periphery of the partition plate (5) is fitted with an elastic sealing ring, which is press-fitted with the inner wall of the box (1), and the elastic sealing ring is made of oil-resistant nitrile rubber.

6. The oil-immersed power transformer with high-efficiency heat dissipation according to claim 5, characterized in that, The elastic cleaning brush (502) is a nylon brush with bristle length adapted to the radial thickness of the winding (2) and the bristle surface is coated with a wear-resistant ceramic coating.

7. The oil-immersed power transformer with high-efficiency heat dissipation according to claim 6, characterized in that, Several fixed fins (16) are arranged in parallel at intervals, and ventilation gaps are formed between adjacent fixed fins (16). The sidewalls of the fixed fins (16) are welded and fixed to the outer wall of the box body (1).

8. An intelligent control system for an oil-immersed power transformer with high-efficiency heat dissipation as described in any one of claims 1-7, characterized in that, include: A temperature sensor is installed in the lower cavity (4) and / or the oil storage channel (22) to detect the temperature of the insulating oil; The controller (25) is connected to the temperature sensor signal; An electric regulating valve (24) is installed on the front section of the main oil outlet pipe (19) and is electrically connected to the controller (25); The controller (25) is configured to control the opening degree of the electric regulating valve (24) according to the received temperature signal.

9. The intelligent control system according to claim 8, characterized in that, It also includes an auxiliary cooling fan (26), which is installed outside the transformer housing (1) and electrically connected to the controller (25). The controller (25) controls its start / stop and speed according to the temperature signal.

10. The intelligent control system according to claim 9, characterized in that, The controller (25) is configured to execute the following control logic: When the detected insulating oil temperature is lower than the first threshold T1, the electric regulating valve (24) is kept closed and the auxiliary cooling fan (26) is turned off. When the detected insulating oil temperature reaches the first threshold T1 and is lower than the second threshold T2, the electric regulating valve (24) is controlled to open to the first opening degree, and the auxiliary cooling fan (26) is started to run at low speed. When the detected insulating oil temperature reaches or exceeds the second threshold T2, the electric regulating valve (24) is controlled to open to the second opening degree, and the auxiliary cooling fan (26) is controlled to run at high speed. Wherein, the first threshold T1 is lower than the second threshold T2, and the first threshold T1 is set to be close to or slightly higher than the phase change temperature starting point of the thermal drive element (18).

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