A dry-type air-cooled transformer and air-cooling method

Abstract

This invention discloses an air-cooled dry-type transformer and its cooling method. The air-cooled dry-type transformer includes concentrically arranged low-voltage coils and high-voltage coils, with an annular gap between the inner wall of the high-voltage coil and the outer wall of the low-voltage coil. The low-voltage coil is wrapped around an iron core, and the wrapped iron core has axially extending air ducts penetrating the upper and lower yokes. The upper and lower ends of the iron core are horizontally clamped and fixed by clamps, which vertically clamp the low-voltage coil and the high-voltage coil. Multiple heat dissipation air ducts are opened along the axial direction of the high-voltage coil, and these air ducts are evenly distributed around the periphery of the high-voltage coil. This invention fundamentally solves the heat dissipation problem of traditional air-cooled transformers through an innovative biaxial synergistic cooling system. This technical solution not only significantly improves the operational reliability and economy of the transformer but also provides reliable technical support for the development of dry-type transformers towards larger capacities.

Description

Technical Field

[0001] This invention relates to a transformer, and more particularly to an air-cooled dry-type transformer and an air-cooling method. Background Technology

[0002] Traditional air-cooled dry-type transformers suffer from significant uneven heat dissipation, primarily manifested in the following ways: the yoke's obstruction of airflow hinders effective airflow into the coils, leading to low heat dissipation efficiency in interphase areas; localized hot spots easily form at the winding outlet side, while other areas experience excessive cooling, resulting in uneven temperature distribution; and existing airflow designs cannot simultaneously meet the heat dissipation requirements of both the coils and the core, leading to either core overheating or excessive coil temperature rise. These problems severely impact the transformer's load capacity and operational reliability, hindering the development of large-capacity dry-type transformers. Summary of the Invention

[0003] To address the shortcomings of the aforementioned technologies, this invention provides an air-cooled dry-type transformer and an air-cooling method.

[0004] To solve the above technical problems, the technical solution adopted by the present invention is: an air-cooled dry-type transformer, including a low-voltage coil and a high-voltage coil arranged concentrically, with an annular gap between the inner wall of the high-voltage coil and the outer wall of the low-voltage coil.

[0005] The low-voltage coil is wrapped around the iron core. The wrapped iron core has an axial air duct that runs through the upper and lower yokes. The upper and lower ends of the iron core are clamped and fixed laterally by clamps, and the low-voltage coil and the high-voltage coil are clamped vertically.

[0006] Multiple cooling channels are opened along the axial direction of the high-voltage coil, and these channels are evenly distributed around the periphery of the high-voltage coil.

[0007] Furthermore, the iron core adopts the EI type, and the iron core forms three sets of three-phase coils including low-voltage coils and high-voltage coils. Three air ducts are opened on the iron core corresponding to the low-voltage coils. The air ducts form rectangular air outlets on the upper yoke and lower yoke.

[0008] Furthermore, the clamping component includes an upper clamping component and a lower clamping component. Multiple fans are connected to the lower clamping component, and the air outlets of the fans face the inlet of the heat dissipation duct.

[0009] Furthermore, the lower edge of the high-voltage coil is higher than the lower edge of the low-voltage coil, so that the high-voltage coil and the low-voltage coil are misaligned to form an air-collecting platform for collecting air; the inlet of the heat dissipation air duct is located within the space enclosed by the air-collecting platform.

[0010] Furthermore, the misalignment height between the high-voltage coil and the low-voltage coil ranges from 15mm to 25mm.

[0011] Furthermore, both the low-voltage coil and the high-voltage coil have elliptical cross-sections, and when the low-voltage coil and the high-voltage coil are arranged concentrically, they form an elliptical annular gap between them. Multiple insulating blocks are provided on the clamp near the annular gap. The insulating blocks are connected to the upper or lower edges of the low-voltage coil and the high-voltage coil through end face intervals. The insulating blocks have protrusions that divide the low-voltage coil and the high-voltage coil, and the protrusions are located inside the annular gap.

[0012] Furthermore, a base is connected below the lower clamp, and the fan is located in the support space formed by the base and the lower clamp. The support space surrounds the lower yoke in the circumferential direction, and multiple fans are evenly distributed in the support space.

[0013] A method for air-cooled dry-type transformer, comprising a method for generating air pressure, wherein the method generates air pressure by simultaneously starting circumferentially distributed fans to form an annular high-pressure air cavity in the support space and the bottom of the air-cooled transformer, and the airflow vertically upward covers the lower yoke section of the iron core and the air collection platform.

[0014] Furthermore, the air-cooling method also includes a biaxial cooling method based on the air pressure generation method, which includes axial cooling of the inner and outer coils and axial cooling of the iron core.

[0015] Furthermore, axial cooling of the inner and outer coils is achieved by airflow continuously passing through the annular gap between the high-voltage coil and the low-voltage coil, as well as the heat dissipation channel of the high-voltage coil; axial cooling of the iron core is achieved by airflow simultaneously and continuously passing through the air duct on the iron core.

[0016] This invention discloses an air-cooled dry-type transformer and its cooling method. Through an innovative biaxial synergistic cooling system, it fundamentally solves the heat dissipation problem of traditional air-cooled transformers. Its core advantages are: a unique elliptical annular gap combined with a four-protruding insulating block design creates a highly efficient heat dissipation channel within a limited space, significantly increasing the coil's heat dissipation area; the parallel design of the core axial airflow channel and the coil heat dissipation airflow channel achieves synchronous and optimized cooling of the core and coil; the combination of the air collection platform structure and the annular high-voltage air cavity improves the uniformity of cooling airflow distribution and eliminates local hot spots; and the overall temperature rise is reduced, significantly increasing the load capacity within the same size. This technical solution not only significantly improves the transformer's operational reliability and economy but also provides reliable technical support for the development of dry-type transformers towards larger capacities. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the three-dimensional structure of the present invention. Figure 1 .

[0018] Figure 2 This is a partial structural diagram of the present invention.

[0019] Figure 3 This is the front view of the present invention.

[0020] Figure 4 This is a schematic diagram of the three-dimensional structure of the present invention. Figure 2 .

[0021] In the diagram: 100, low-voltage coil; 200, high-voltage coil; 300, iron core; 400, clamp; 500, fan; 600, air collection platform; 700, insulating block; 800, base; 201, heat dissipation duct; 202, annular gap; 301, air duct; 401, upper clamp; 402, lower clamp. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0023] In this embodiment, as Figure 1 The air-cooled dry-type transformer shown includes a low-voltage coil 100 and a high-voltage coil 200 arranged concentrically, with the low-voltage coil inside and the high-voltage coil outside. The low-voltage coil has a lower voltage and is placed inside, while the high-voltage coil has a higher voltage and is placed outside for better heat dissipation. There is an annular gap 202 between the inner wall of the high-voltage coil 200 and the outer wall of the low-voltage coil 100. This annular gap serves as a heat dissipation channel for both the hollow area inside the high-voltage coil and the outside of the low-voltage coil. It is essentially part of the hollow channel inside the high-voltage coil. The annular gap is determined by the shape of the high-voltage coil and the low-voltage coil. In this embodiment, the cross-sections of both the low-voltage coil 100 and the high-voltage coil 200 are elliptical, and an elliptical annular gap is formed between them when they are arranged concentrically.

[0024] In other embodiments, high-voltage coils and low-voltage coils with circular or polygonal cross-sections can be used. The shape is not limited, but elliptical is preferred. Compared with other shapes, circular coils have a more compact spacing when arranged side by side. Compared with circles, they can provide a larger heat dissipation channel cross-sectional area and a larger effective heat dissipation area for the same circumference.

[0025] In this embodiment, as Figure 2 The low-voltage coil 100 shown is wrapped around the iron core 300. The wrapped iron core 300 has an axial air duct 301 that runs through the upper and lower iron yokes. This air duct is inside the iron core, so it can accelerate the heat dissipation inside the iron core. The iron core 300 adopts the EI type. The iron core 300 forms three sets of three-phase coils including the low-voltage coil 100 and the high-voltage coil 200. A three-level air duct 301 is opened on the upper side of the iron core 300 wrapped in the low-voltage coil 100. The air duct 301 forms a rectangular air outlet on both the upper and lower iron yokes.

[0026] In this embodiment, as Figure 1As shown, the upper and lower ends of the iron core 300 are clamped and fixed laterally by clamps 400. The clamps include upper clamps 401 and lower clamps 402. A pair of upper clamps 401 are provided along the length direction, corresponding to the positions of the upper yoke near the iron core. A pair of lower clamps 402 are provided along the length direction, corresponding to the positions of the lower yoke near the iron core. The clamps 400 vertically clamp the low-voltage coil 100 and the high-voltage coil 200 and support them to form an annular gap between them. Specifically, this annular gap is formed by the combined action of the clamps and the insulating block, with clamps positioned near the annular gap on the clamps 400. There are four insulating blocks 700. The insulating blocks 700 are connected to the upper or lower edges of the low-voltage coil 100 and the high-voltage coil 200 through end face intervals. The insulating blocks 700 have protrusions 701 that divide the low-voltage coil 100 and the high-voltage coil 200. The protrusions 701 are located in the annular gap 202. Each annular gap 202 has four protrusions in its opening. The gaps are evenly distributed by the action of the protrusions. Therefore, the insulating blocks are an important part of the fixing structure, the flow guiding structure and the insulation structure. They divide the annular gaps into regular flow channels and achieve the best balance of mechanical strength, heat dissipation performance and electrical reliability in a limited space.

[0027] In this embodiment, a plurality of heat dissipation channels 201 are formed along the axial direction of the high voltage coil 200. The plurality of heat dissipation channels 201 are evenly distributed on the periphery of the high voltage coil 200. The cross-section of the heat dissipation channel 201 is preferably rectangular, but not limited to rectangular, and other shapes may also be used.

[0028] All the above embodiments are design schemes based on natural wind. In some other embodiments, based on the above embodiments, multiple fans 500 are connected to the lower clamp 402, and the air outlets of the fans 500 face the inlet of the heat dissipation duct 201. The corresponding design is that the lower edge of the high-voltage coil 200 is higher than the lower edge of the low-voltage coil 100, so that the high-voltage coil 200 and the low-voltage coil 100 are staggered to form a wind collection platform 600 for collecting air; the inlet of the heat dissipation duct 201 is located within the space enclosed by the wind collection platform 600. The stagger height between the high-voltage coil 200 and the low-voltage coil 100 is in the range of 15mm-25mm, preferably 20mm; a base 800 is connected below the lower clamp 402, and the fans 500 are located in the support space formed by the base 800 and the lower clamp 402. The support space surrounds the lower yoke circumferentially, and multiple fans 500 are evenly distributed within the support space. Therefore, the present invention also forms an air-cooling method for air-cooled dry-type transformers. The air-cooling method includes an air pressure generation method. The air pressure generation method forms an annular high-pressure air cavity in the support space and the bottom of the air-cooled transformer by synchronously starting circumferentially distributed fans. The airflow vertically upward covers the lower yoke section of the iron core and the air collection platform.

[0029] The air-cooling method also includes a biaxial cooling method based on the wind pressure generation method, which includes axial cooling of the inner and outer coils and axial cooling of the iron core.

[0030] Axial cooling of the inner and outer coils is achieved by continuous airflow through the annular gap between the high-voltage and low-voltage coils, as well as the heat dissipation duct of the high-voltage coil; axial cooling of the core is achieved by simultaneous and continuous airflow through the air duct on the core. It should be noted that although the fan does not blow directly onto the air duct, the airflow effect created by the high-pressure airflow is sufficient to ensure simultaneous airflow within the air duct throughout the lower part of the transformer.

[0031] Specifically, the air-cooling method described in this invention significantly improves the overall heat dissipation efficiency of the transformer through an innovative biaxial synergistic cooling mechanism. The synergistic effect of this method is mainly reflected in three dimensions: First, in terms of airflow organization, the circumferentially distributed fan group forms an annular high-pressure air cavity at the bottom. Through fluid dynamics optimization, the airflow is vertically and evenly distributed upwards to cover the lower yoke section of the iron core, while the Venturi effect of the air collection platform enhances the intake efficiency. Second, in terms of the cooling path, a dual internal and external circulation is achieved—the external airflow flows axially along the parallel channel formed by the high-voltage coil cooling air duct and the annular gap, while the internal airflow directly cools the core column through the iron core air duct. The two systems are spatially complementary and their air pressure is balanced. Simultaneously, in conjunction with thermodynamic synergy, the staggered design of the high-voltage coil significantly increases the airflow velocity and collection capacity at the air collection platform, while the guiding effect of the protruding insulation block ensures the formation of a stable four-channel vortex within the annular gap. Combined with the rectangular air outlet design of the iron core air duct, the overall heat dissipation area is significantly increased compared to traditional structures. This three-dimensional cooling system achieves a triple breakthrough in heat dissipation efficiency, energy economy, and structural reliability.

[0032] The above embodiments are not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the technical solution of the present invention are also within the protection scope of the present invention.

Claims

1. An air-cooled dry-type transformer characterized by comprising: The low-voltage coil (100) and the high-voltage coil (200) are arranged concentrically, and an annular gap (202) is formed between the inner wall of the high-voltage coil (200) and the outer wall of the low-voltage coil (100); The low-voltage coil (100) is wrapped around the iron core (300), and the wrapped iron core (300) has an air duct (301) penetrating through the upper and lower iron yokes in the axial direction; the upper and lower ends of the iron core (300) are clamped and fixed in the transverse direction by a clamp (400), and the low-voltage coil (100) and the high-voltage coil (200) are clamped and fixed in the vertical direction by the clamp (400); A plurality of heat dissipation air channels (201) are formed in the axial direction of the high-voltage coil (200), and the plurality of heat dissipation air channels (201) are uniformly distributed on the circumference of the high-voltage coil (200); The iron core (300) is of E-I type, and the iron core (300) forms three sets of three-phase coils including the low-voltage coil (100) and the high-voltage coil (200); three air ducts (301) are formed on the iron core (300) wrapped around the low-voltage coil (100), and the air ducts (301) form rectangular air ports in the upper and lower iron yokes; The lower edge of the high-voltage coil (200) is higher than the lower edge of the low-voltage coil (100), so that the high-voltage coil (200) and the low-voltage coil (100) are misaligned to form a wind collecting platform (600) for collecting wind; the inlet of the heat dissipation air channel (201) is located in the space surrounded by the wind collecting platform (600).

2. The air-cooled dry-type transformer of claim 1, wherein: The clamp (400) includes an upper clamp (401) and a lower clamp (402), and a plurality of fans (500) are connected to the lower clamp (402); the outlets of the fans (500) face the inlets of the heat dissipation air channels (201).

3. The air-cooled dry-type transformer of claim 2, wherein: The misalignment height between the high-voltage coil (200) and the low-voltage coil (100) ranges from 15 mm to 25 mm.

4. The air-cooled dry-type transformer of claim 3, wherein: The cross sections of the low-voltage coil (100) and the high-voltage coil (200) are both elliptical, and when the low-voltage coil (100) and the high-voltage coil (200) are arranged concentrically, an elliptical annular gap is formed between them; a plurality of insulating blocks (700) are arranged on the clamp (400) near the annular gap; the insulating blocks (700) are connected to the upper edges or the lower edges of the low-voltage coil (100) and the high-voltage coil (200) by end face spacing; the insulating blocks (700) have protrusions (701) for dividing the low-voltage coil (100) and the high-voltage coil (200), and the protrusions (701) are located in the annular gap.

5. The air-cooled dry-type transformer of claim 4, wherein: A base (800) is connected to the lower clamp (402), and the fans (500) are located in a support space formed by the base (800) and the lower clamp (402); the support space surrounds the periphery of the lower iron yoke in the circumferential direction, and the plurality of fans (500) are uniformly distributed in the support space.

6. The air cooling method of the air-cooled dry-type transformer according to claim 5, characterized by: The air cooling method includes an air pressure generation method, which forms an annular high-pressure air chamber in the support space and the bottom of the air-cooled transformer by synchronously starting the circumferentially distributed fans, and the airflow vertically upward covers the cross section of the lower iron yoke of the iron core and the wind collecting platform.

7. The air cooling method of the air-cooled dry-type transformer according to claim 6, characterized by: The air cooling method further comprises a double-axial cooling method based on an air pressure generation method, the double-axial cooling method comprising inner and outer coil axial cooling and core axial cooling.

8. The air cooling method of the air-cooled dry-type transformer according to claim 7, characterized by: The inner and outer coil axial cooling is achieved by uninterrupted airflow through an annular gap between the high-voltage coil and the low-voltage coil and a heat dissipation air duct of the high-voltage coil; and the core axial cooling is achieved by simultaneous and uninterrupted airflow through air ducts on the core.

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