Air-cooled dry-type transformer and air cooling method

Abstract

The invention discloses an air-cooled dry-type transformer and a cooling method, the air-cooled dry-type transformer comprises a low-voltage coil and a high-voltage coil which are concentrically arranged, and an annular gap exists between the inner wall of the high-voltage coil and the outer wall of the low-voltage coil; the low-voltage coil is wrapped outside the iron core, the wrapped iron core is provided with an air channel penetrating through the upper iron yoke and the lower iron yoke in the axial direction, the upper end and the lower end of the iron core are clamped and fixed in the transverse direction through clamping pieces, and the low-voltage coil and the high-voltage coil are vertically clamped; a plurality of heat dissipation air channels are formed in the axial direction of the high-voltage coil and evenly distributed on the periphery of the high-voltage coil. By means of the innovative biaxial collaborative cooling system, the heat dissipation problem of a traditional air-cooled transformer is fundamentally solved. According to the technical scheme, the operation reliability and economical efficiency of the transformer are remarkably improved, and reliable technical support is provided for the development of the dry-type transformer towards larger capacity.

Description

Technical Field

[0001] The present invention relates to a transformer, and in particular to an air-cooled dry-type transformer and an air-cooling method. Background Art

[0002] Traditional air-cooled dry-type transformers suffer from significant uneven heat dissipation. These issues primarily manifest as follows: The iron yoke blocks airflow, preventing cooling air from effectively entering the coils, resulting in inefficient heat dissipation between phases; localized hot spots form at the ends of the winding outlets, while other areas are overcooled, causing uneven temperature distribution; and existing air duct 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 issues severely impact the transformer's load capacity and operational reliability, hindering the development of large-capacity dry-type transformers. Summary of the Invention

[0003] In order to solve the deficiencies of the above technologies, the present invention provides an air-cooled dry-type transformer and an air-cooling method.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: an air-cooled dry-type transformer, comprising 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; The low-voltage coil is wrapped around the iron core. The wrapped iron core has an air duct that runs axially through the upper and lower iron yokes. The upper and lower ends of the iron core are clamped and fixed horizontally by clamps, and the low-voltage coil and high-voltage coil are clamped vertically. A plurality of heat dissipation air channels are opened along the axial direction of the high-voltage coil, and the plurality of heat dissipation air channels are evenly distributed on the circumference of the high-voltage coil.

[0005] Furthermore, the iron core adopts EI type, and the iron core forms three groups of three-phase coils including low-voltage coils and high-voltage coils, and three air ducts are opened on the iron core corresponding to the low-voltage coils, and the air ducts form rectangular air outlets on the upper iron yoke and the lower iron yoke.

[0006] Furthermore, the clamp includes an upper clamp and a lower clamp, and the lower clamp is connected to a plurality of fans, and the air outlets of the fans face the inlet of the heat dissipation duct.

[0007] 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 offset to form a wind collecting platform for collecting wind; the inlet of the heat dissipation air duct is located in the space enclosed by the wind collecting platform.

[0008] Furthermore, the offset height between the high-voltage coil and the low-voltage coil ranges from 15 mm to 25 mm.

[0009] Furthermore, the cross-sections of the low-voltage coil and the high-voltage coil are both elliptical, and when the low-voltage coil and the high-voltage coil are arranged concentrically, an elliptical annular gap is formed between the two. A plurality of insulating blocks are arranged 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 spacing. The insulating blocks have a protrusion that separates the low-voltage coil and the high-voltage coil, and the protrusion is located in the annular gap.

[0010] Furthermore, a base is connected below the lower clamp, and the fan is located between the base and the lower clamp to form a support space. The support space circumferentially surrounds the outer periphery of the lower iron yoke, and multiple fans are evenly distributed in the support space.

[0011] A method for cooling an air-cooled dry-type transformer includes a method for generating wind pressure. The method forms an annular high-pressure wind cavity in a support space and the bottom of the air-cooled transformer by synchronously starting circumferentially distributed fans. The airflow vertically covers the iron yoke section under the iron core and the wind collecting platform.

[0012] Furthermore, the air cooling method also includes a biaxial cooling method based on the wind pressure generation method, and the biaxial cooling method includes axial cooling of the inner and outer coils and axial cooling of the iron core.

[0013] Furthermore, axial cooling of the inner and outer coils is achieved by uninterrupted airflow through the annular gap between the high-voltage coil and the low-voltage coil, as well as the heat dissipation air duct of the high-voltage coil; axial cooling of the iron core is achieved by simultaneous and uninterrupted airflow through the air duct on the iron core.

[0014] The present invention discloses an air-cooled dry-type transformer and an air-cooling method. Through an innovative dual-axial collaborative cooling system, it fundamentally solves the heat dissipation problem of traditional air-cooled transformers. Its core advantages are reflected in: the unique elliptical annular gap is combined with the four-raised insulating block design to build an efficient heat dissipation channel in a limited space, which greatly increases the heat dissipation area of ​​the coil; the parallel design of the core axial air duct and the coil heat dissipation air duct realizes the synchronous optimized cooling of the core and the coil; the combination of the wind collecting platform structure and the annular high-pressure air cavity improves the uniformity of the cooling air flow distribution and eliminates local hot spots; the overall temperature rise is reduced, and the load capacity can be greatly improved under the same size. This technical solution not only significantly improves the operating reliability and economy of the transformer, but also provides reliable technical support for the development of dry-type transformers to larger capacities. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the three-dimensional structure of the present invention Figure 1 .

[0016] Figure 2 It is a schematic diagram of the local structure of the present invention.

[0017] Figure 3 It is the front view of the present invention.

[0018] Figure 4 Schematic diagram of the three-dimensional structure of the present invention Figure 2 .

[0019] In the figure: 100, low-voltage coil; 200, high-voltage coil; 300, iron core; 400, clamp; 500, fan; 600, wind collecting platform; 700, insulation block; 800, base; 201, heat dissipation duct; 202, annular gap; 301, air duct; 401, upper clamp; 402, lower clamp. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] In this embodiment, Figure 1 The air-cooled dry-type transformer shown includes a concentrically arranged low-voltage coil 100 and a high-voltage coil 200, with the low-voltage coil inside and the high-voltage coil outside. The voltage of the low-voltage coil is lower and it is placed inside. The voltage of the high-voltage coil is relatively high and it is more conducive to heat dissipation when placed outside. 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 the hollow area inside the high-voltage coil and a heat dissipation channel outside the low-voltage coil. It is essentially a part of the hollow channel inside the high-voltage coil. The annular gap depends on the shape of the high-voltage coil and the low-voltage coil. The cross-sections of the low-voltage coil 100 and the high-voltage coil 200 adopted in this embodiment are both elliptical, and an elliptical annular gap is formed between the low-voltage coil 100 and the high-voltage coil 200 when they are concentrically arranged.

[0022] In other embodiments, high-voltage coils and low-voltage coils with circular or polygonal cross-sections can be used. The shape is not limited, and elliptical is the preferred option. Compared with other shapes, circular coils have more compact gaps when arranged in parallel; compared with circles, they can provide a larger heat dissipation channel cross-sectional area and a larger effective heat dissipation area at the same circumference.

[0023] In this embodiment, if Figure 2 The low-voltage coil 100 shown is wrapped around the iron core 300, and the wrapped iron core 300 has an air duct 301 that runs axially through the upper iron yoke and the lower iron yoke. 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, and the iron core 300 forms three groups of three-phase coils including low-voltage coils 100 and high-voltage coils 200, and a three-level air duct 301 is opened on the upper side of the iron core 300 wrapped in the low-voltage coil 100, and the air duct 301 forms a rectangular air outlet on the upper iron yoke and the lower iron yoke.

[0024] In this embodiment, if Figure 1As shown, the upper and lower ends of the iron core 300 are clamped and fixed in the horizontal direction by the clamp 400, and the clamp includes an upper clamp 401 and a lower clamp 402. A pair of upper clamps 401 are provided in the length direction, corresponding to the position of the upper iron yoke of the iron core, and a pair of lower clamps 402 are provided in the length direction, corresponding to the position of the lower iron yoke of the iron core. The clamp 400 vertically clamps the low-voltage coil 100 and the high-voltage coil 200 and supports the formation of an annular gap between the two. Specifically, the formation of this annular gap is formed by the joint action of the clamp and the insulating block. The position near the annular gap on the clamp 400 is set There are four insulating blocks 700, which are connected to the upper or lower edges of the low-voltage coil 100 and the high-voltage coil 200 through end face spacing. The insulating block 700 has a protrusion 701 that separates the low-voltage coil 100 and the high-voltage coil 200. The protrusion 701 is located in the annular gap 202. Four protrusions are provided in the opening of each annular gap 202. The gap is evenly distributed under the action of the protrusion. Therefore, the insulating block serves as an important part of the fixed structure, the flow guide structure and the insulating structure, and divides the annular gap into regular flow channels to achieve the best balance of mechanical strength, heat dissipation performance and electrical reliability in a limited space.

[0025] In this embodiment, multiple heat dissipation ducts 201 are opened along the axial direction of the high-voltage coil 200. The multiple heat dissipation ducts 201 are evenly distributed around the circumference of the high-voltage coil 200. The cross-section of the heat dissipation duct 201 is preferably rectangular, but is not limited to a rectangle, and other shapes can also be used.

[0026] All of the above embodiments are based on the design scheme under natural wind. In some other embodiments, on the basis of the above embodiments, a plurality of fans 500 are connected to the lower clamp 402, and the air outlet of the fan 500 faces the inlet of the heat dissipation duct 201. The matching design is to make the lower edge of the high-voltage coil 200 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 offset to form a wind collecting platform 600 for collecting wind; the inlet of the heat dissipation duct 201 is located in the space enclosed by the wind collecting platform 600. The offset height between the high-voltage coil 200 and the low-voltage coil 100 ranges from 15mm to 25mm, preferably 20mm; a base 800 is connected to the bottom of the lower clamp 402, and the fan 500 is located at the base 800 and the lower clamp 402 to form a support space. The support space is circumferentially surrounded by the outer periphery of the lower iron yoke, and a plurality of fans 500 are evenly distributed in the support space. The present invention thus also forms an air-cooling method for an air-cooled dry-type transformer, which includes a wind pressure generating method. The wind pressure generating method forms an annular high-pressure wind cavity in the support space and the bottom of the air-cooled transformer by synchronously starting circumferentially distributed fans, and the air flow vertically covers the iron yoke section under the iron core and the wind collecting platform.

[0027] The air cooling method also includes a biaxial cooling method based on a wind pressure generation method, and the biaxial cooling method includes axial cooling of inner and outer coils and axial cooling of the iron core.

[0028] 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 ducts of the high-voltage coils. Axial cooling of the core is achieved by simultaneous and continuous airflow through the ducts on the core. It is important to note that although the fan does not blow directly into the ducts, the air flow generated by the high-pressure airflow throughout the lower portion of the transformer is sufficient to simultaneously circulate air within the ducts.

[0029] In particular, the air cooling method described in the present invention significantly improves the overall heat dissipation efficiency of the transformer through an innovative biaxial collaborative cooling mechanism. The synergistic effect of this method is mainly reflected in three dimensions: first, in terms of airflow organization, a group of fans evenly distributed around the circumference form an annular high-pressure air cavity at the bottom. Through fluid dynamics optimization, the airflow is vertically and evenly distributed over the cross-section of the lower yoke of the core, while the Venturi effect of the air collecting platform is used to enhance the air intake efficiency. Second, the cooling path realizes an internal and external dual circulation: the external airflow flows axially along the parallel channel formed by the high-voltage coil heat dissipation air duct and the annular gap, while the internal airflow directly cools the core column through the core air duct. The two systems complement each other in space and the wind pressure is balanced. At the same time, in conjunction with thermodynamic synergy, the staggered design of the high-voltage coil greatly improves the airflow velocity and collection capacity at the air collecting platform, while the guiding effect of the insulating block protrusion ensures the formation of a stable four-channel vortex in the annular gap. Combined with the rectangular air outlet design of the core air duct, the overall heat dissipation area is significantly increased compared to the traditional structure. This three-dimensional cooling system achieves a triple breakthrough in heat dissipation efficiency, energy economy and structural reliability.

[0030] The above embodiments are not limitations of the present invention, and the present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by technicians in this technical field within the scope of the technical solution of the present invention also fall within the scope of protection of the present invention.

Claims

1. An air-cooled dry-type transformer, characterized in that: It comprises a low-voltage coil (100) and a high-voltage coil (200) arranged concentrically, wherein an annular gap (202) exists 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) that axially penetrates the upper iron yoke and the lower iron yoke. The upper and lower ends of the iron core (300) are clamped and fixed in the horizontal direction by clamps (400), and the low-voltage coil (100) and the high-voltage coil (200) are clamped in the vertical direction. A plurality of heat dissipation air channels (201) are provided along the axial direction of the high-voltage coil (200), and the plurality of heat dissipation air channels (201) are evenly distributed around the circumference of the high-voltage coil (200).

2. The air-cooled dry-type transformer according to claim 1, characterized in that: The iron core (300) is of EI type, and the iron core (300) forms three groups of three-phase coils including a low-voltage coil (100) and a high-voltage coil (200), and three air ducts (301) are opened on the iron core (300) corresponding to the low-voltage coil (100), and the air ducts (301) form rectangular air outlets on both the upper iron yoke and the lower iron yoke.

3. The air-cooled dry-type transformer according to claim 1 or 2, characterized in that: The clamp (400) comprises an upper clamp (401) and a lower clamp (402); a plurality of fans (500) are connected to the lower clamp (402); and air outlets of the fans (500) face the inlet of the heat dissipation duct (201).

4. The air-cooled dry-type transformer according to claim 3, characterized in 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 offset to form a wind collecting platform (600) for collecting wind; the inlet of the heat dissipation air duct (201) is located in the enclosed space of the wind collecting platform (600).

5. The air-cooled dry-type transformer according to claim 4, characterized in that: The offset height between the high-voltage coil (200) and the low-voltage coil (100) ranges from 15 mm to 25 mm.

6. The air-cooled dry-type transformer according to claim 3, characterized in that: 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 the two. A plurality of insulating blocks (700) are provided on the clamp (400) at positions close to the annular gap. The insulating blocks (700) are connected to the upper edges or lower edges of the low-voltage coil (100) and the high-voltage coil (200) through end face spacing. The insulating blocks (700) have a protrusion (701) for dividing the low-voltage coil (100) and the high-voltage coil (200), and the protrusion (701) is located in the annular gap.

7. The air-cooled dry-type transformer according to claim 6, characterized in that: A base (800) is connected below the lower clamp (402), and the fan (500) is located between the base (800) and the lower clamp (402) to form a support space. The support space is circumferentially surrounded by the outer periphery of the lower iron yoke, and a plurality of fans (500) are evenly distributed in the support space.

8. A method for cooling an air-cooled dry-type transformer, characterized in that: The air cooling method includes a wind pressure generating method, which forms an annular high-pressure wind cavity in the support space and the bottom of the air-cooled transformer by synchronously starting circumferentially distributed fans, and the air flow vertically covers the iron yoke section under the iron core and the wind collecting platform.

9. The air cooling method for an air-cooled dry-type transformer according to claim 8, characterized in that: The air cooling method also includes a biaxial cooling method based on a wind pressure generation method, and the biaxial cooling method includes axial cooling of inner and outer coils and axial cooling of the iron core.

10. The air cooling method for an air-cooled dry-type transformer according to claim 9, characterized in that: The axial cooling of the inner and outer coils is achieved by the airflow continuously passing through the annular gap between the high-voltage coil and the low-voltage coil, and the heat dissipation air duct of the high-voltage coil; the axial cooling of the iron core is achieved by the airflow simultaneously and continuously passing through the air duct on the iron core.

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