Reinforced heat dissipation structure of epoxy pouring dry-type transformer and manufacturing process of reinforced heat dissipation structure

Abstract

According to the reinforced heat dissipation structure of the epoxy pouring dry-type transformer and the manufacturing process of the reinforced heat dissipation structure, the reinforced heat dissipation structure of the epoxy pouring dry-type transformer comprises an iron core, a winding, a base and a heat dissipation device; the winding comprises a low-voltage winding and a high-voltage winding, the low-voltage winding sleeves the outer side of a core column of the iron core, the high-voltage winding sleeves the outer side of the low-voltage winding, and a main channel is reserved between the high-voltage winding and the low-voltage winding; and the heat dissipation element is arranged in a main channel formed by the high-voltage winding and the low-voltage winding. The high-voltage side heat conduction layer is connected with the inner wall of the high-voltage winding, the low-voltage side heat conduction layer is connected with the outer wall of the low-voltage winding, the heat conduction efficiency is improved, meanwhile, the heat dissipation element is installed in the main channel, and the heat dissipation capacity of the main channel is enhanced. In addition, the heat dissipation device and the winding are integrally formed in a casting mode, the heat dissipation capacity of the main channel is enhanced, heat resistance among all components is effectively reduced, and therefore the overall heat conduction efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of high-efficiency and energy-saving dry-type transformers, and in particular relates to an enhanced heat dissipation structure of an epoxy cast dry-type transformer and a manufacturing process thereof. Background Art

[0002] During the operation of the transformer, heat generation and heat dissipation occur simultaneously. The core winding and other structural parts generate heat during operation, which is then transferred out through heat conduction and heat convection, and finally the transformer structural parts reach a stable temperature balance. The heat generated by the core winding during operation causes the temperature of the surrounding air fluid to rise. After the air fluid temperature rises, it moves upward. The air fluid has a tendency to increase in temperature in the upward direction. The air fluid temperature at the upper end of the winding is higher, resulting in a smaller temperature difference between the winding and the upper end of the core and the air fluid, that is, the heat dissipation capacity of the winding and the upper end of the core is poor, resulting in a higher temperature at the upper end of the winding, and the hottest point temperature appears at the upper end of the winding.

[0003] At present, the known epoxy cast dry-type transformer is assembled by an iron core, a high-voltage winding, a low-voltage winding and its accessories such as a pressure pad. The low-voltage winding is sleeved on the iron core, and the high-voltage winding is sleeved on the outside of the low-voltage winding. The high and low voltage windings are fixed to the iron core by the upper and lower iron yokes, clamps and pressure pads of the iron core. The heat dissipation method mainly dissipates heat through the main channel between the high and low voltage windings, the gap between the low voltage winding and the iron core, the air channel of the high voltage winding and its outer surface, and the air channel of the low voltage winding. This structure has the following problems:

[0004] 1. The main channel gap between the high and low voltage windings is affected by the dimensions and process of the high and low voltage windings. The unevenness of the gap size seriously affects the impedance value and temperature rise value of the transformer;

[0005] 2. This type of transformer mainly uses traditional heat dissipation methods such as heat convection, heat conduction, and heat radiation. Its heat dissipation capacity is limited, which seriously hinders the development of transformers towards miniaturization, lightness, high efficiency and energy saving;

[0006] 3. Although the pads placed at both ends of the high and low voltage coils ensure the stability of the coils, the pads block the heat dissipation channel and affect the heat dissipation capacity of the transformer; in addition, the pads are separated from the high and low voltage coils, which increases the assembly size error and reduces the stability of the system;

[0007] 4. The core clamp uses a structure of bent channel steel or steel plate to fix the pad block, but the bent part not only affects the heat dissipation of the transformer, but also increases the stray loss of the transformer. Therefore, it is urgent to provide a new enhanced heat dissipation structure and manufacturing process of epoxy cast dry-type transformer. Summary of the invention

[0008] Purpose of the Invention

[0009] The purpose of the present invention is to provide an enhanced heat dissipation structure of an epoxy cast dry-type transformer and a manufacturing process thereof, so as to solve the problem of limited heat dissipation capacity of dry-type transformers in the prior art.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] An enhanced heat dissipation structure of an epoxy cast dry-type transformer, comprising an iron core, a winding, a base and a heat dissipation device;

[0012] A lower clamp for clamping the lower iron yoke of the iron core is fixedly connected to the top of the base, and the upper iron yoke of the iron core at one end away from the base is clamped and fixed by the upper clamp;

[0013] The winding includes a low-voltage winding and a high-voltage winding, wherein the low-voltage winding is sleeved on the outside of the core column of the iron core, and a gap is left between the inner side wall of the low-voltage winding and the core column of the iron core; the high-voltage winding is sleeved on the outside of the low-voltage winding, and a main channel is left between the high-voltage winding and the low-voltage winding;

[0014] The heat dissipation device includes a high-voltage side heat-conducting layer, a low-voltage side heat-conducting layer and a heat dissipation element; the high-voltage side heat-conducting layer is arranged on the inner wall and the outer wall of the high-voltage winding; the low-voltage side heat-conducting layer is arranged on the inner wall of the low-voltage winding; the heat dissipation element is arranged in the main channel formed by the high-voltage winding and the low-voltage winding.

[0015] Furthermore, the high-voltage side heat-conducting layer includes an inner heat-collecting layer and an outer heat-collecting layer, the outer heat-collecting layer is arranged on the outer wall of the high-voltage winding; the inner heat-collecting layer is arranged on the inner wall of the high-voltage winding, and one side of the inner heat-collecting layer is adjacent to the main channel; the heat dissipation device also includes a heat-conducting column and a heat-conducting sheet, one side of the heat-conducting column is arranged on the inner heat-collecting layer, the other end of the heat-conducting column is connected to the outer heat-collecting layer, and the heat-conducting column is provided with an installation groove; the heat-conducting sheet is fixed to the installation groove of the heat-conducting column by clamping.

[0016] Furthermore, the winding adopts an epoxy casting process and the pad block structure is eliminated; a plurality of heat-conducting columns are provided, and the plurality of heat-conducting columns are arranged at intervals along the circumference of the high-voltage winding to form a heat-conducting layer, and the heat-conducting layer is arranged between each group of coils in the high-voltage winding; one end of the heat-conducting plate is connected to the heat-conducting column, and the other end of the heat-conducting plate extends upward and is arranged circumferentially along the top surface of each group of coils in the high-voltage winding.

[0017] Furthermore, the iron core is made of silicon steel sheets; the upper clamp includes a first fixing plate and a first pull rod, the first fixing plate is a planar structure, two first fixing plates are provided, and the two first fixing plates are arranged in parallel; the two first fixing plates are connected by a first pull rod, and when the iron core is installed, the upper iron yoke of the iron core away from the base is clamped and fixed by the two first fixing plates and the first pull rod of the upper clamp;

[0018] The lower clamp includes a second fixed plate and a second pull rod. There are two second fixed plates, and the two second fixed plates are arranged in parallel. The top and bottom of the second fixed plate are respectively provided with an upper flange and a lower flange, wherein the upper flange is provided with a fixed support at intervals, and the fixed support is a bending structure, wherein the bending structure extends outward along the width direction of the upper flange, and a fixing frame is arranged on the fixed support, and the lower flange of the second fixed plate is fixedly connected to the transformer base by bolts; the bottom of the low-voltage winding and the high-voltage winding are fixed to the fixed support on the flange of the second fixed plate by a fixing frame; when the iron core is installed, the lower iron yoke of the iron core is clamped and fixed by the two second fixed plates and the second pull rod of the lower clamp.

[0019] Furthermore, the high-voltage side heat-conducting layer and the low-voltage side heat-conducting layer are respectively arranged on the high-voltage winding and the low-voltage winding by gluing or pressing with insulating glue.

[0020] Furthermore, the heat dissipation element includes a plurality of heat dissipation fins, each of which is arranged at equal intervals in the main channel formed by the high-voltage winding and the low-voltage winding, the cross-sectional shape of the heat dissipation fin is rectangular, and the panel of the heat dissipation fin is arrayed with serrated protrusions, the thickness of the heat dissipation fin is not more than 3 mm, and the heat dissipation fin is made of a material with high thermal conductivity; the number of heat dissipation elements is calculated by the following formula:

[0021] In the formula: S is the heat dissipation area of ​​the heat dissipation element, a is the comprehensive heat transfer coefficient, n is the number of heat dissipation elements, P is the loss of the winding, τ is the average temperature rise, b is the surface heat dissipation coefficient of the heat dissipation element, and A is the surface area of ​​the winding.

[0022] The manufacturing process of the enhanced heat dissipation structure of the epoxy cast dry-type transformer mentioned above includes the following steps:

[0023] Step A: Making the silicon steel sheet into an iron core;

[0024] Step B: Install the heat sink in the main channel between the high voltage winding and the low voltage winding;

[0025] Step C: The winding with the heat dissipation device is mounted on the iron core to form a structure of an epoxy cast dry-type transformer, and the heat dissipation device is used to enhance the heat dissipation of the main channel.

[0026] Furthermore, in step B, the heat sink and the high-voltage winding and the low-voltage winding are integrally cast, and reinforcing ribs are provided during the casting process.

[0027] Furthermore, in the step B, the winding is first cast, and after the casting is completed, the heat sink is fixed between the high-voltage winding and the low-voltage winding by a fixing frame, and then the heat sink is cast.

[0028] Advantages and effects of the present invention:

[0029] 1. This invention applies enhanced heat dissipation technology to the technical field of epoxy cast dry-type transformers in an original way, and uses enhanced heat dissipation technology to improve the heat dissipation efficiency of the main channel, fundamentally changing the heat dissipation mode of epoxy cast dry-type transformers, and maximizing the heat dissipation capacity of the main channel, which can significantly reduce the temperature rise of epoxy cast dry-type transformers. At the same time, it provides an original technical solution for the development of epoxy cast dry-type transformers in the direction of lightweight, miniaturization, high efficiency and energy saving.

[0030] 2. The present invention originally proposes to form an integrated structure between the heat dissipation device and the high-voltage winding and the low-voltage winding by integral casting, which not only reduces the difficulty of the transformer assembly process, but also ensures the consistency of the main channel size, thereby reducing the impact of the main channel size deviation on the transformer impedance value and heat dissipation capacity.

[0031] 3. The present invention eliminates the pad block fixing structure of the high and low voltage windings in the prior art by cooperating with the upper clamp and the lower clamp, which improves the structural stability of the transformer on the one hand, and reduces the influence of the pad block on the heat dissipation of the transformer on the other hand, and reduces the stray loss of the core clamp. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 An overall schematic diagram of the heat dissipation structure of an epoxy cast dry-type transformer according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the core connection structure of a dry-type transformer according to an embodiment of the present invention;

[0034] Figure 3 A schematic diagram of a winding connection structure of a dry-type transformer according to an embodiment of the present invention;

[0035] Figure 4 A schematic diagram of the winding structure of a dry-type transformer according to an embodiment of the present invention;

[0036] Figure 5 A schematic top view of a winding structure of a dry-type transformer according to an embodiment of the present invention;

[0037] Figure 6 This is a partial diagram of the high-voltage winding of a dry-type transformer according to an embodiment of the present invention.

[0038] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0039] 1. Iron core; 102. First fixed plate; 103. Second fixed plate; 104. First pull rod; 2. Winding; 201. High-voltage winding; 202. Low-voltage winding; 3. Heat dissipation device; 301. High-voltage side heat-conducting layer; 3011. High-voltage outer heat-collecting layer; 3012. High-voltage inner heat-collecting layer; 302. Low-voltage outer heat-collecting layer 303. Heat dissipation element; 304. Fixed frame; 3041. Support foot; 3042. Lower pad; 305. Heat-conducting sheet; 306. Heat-conducting column; 4. Main channel. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] like Figure 1-Figure 6 As shown, an enhanced heat dissipation structure of an epoxy cast dry-type transformer of the present invention comprises an iron core 1, a winding 2, a base and a heat dissipation device 3; wherein a lower clamp for clamping the lower iron yoke of the iron core 1 is fixedly connected to the top of the base, and the upper iron yoke of the iron core 1 at one end away from the base is clamped and fixed by the upper clamp; wherein the winding 2 comprises a low-voltage winding 202 and a high-voltage winding 201, wherein the low-voltage winding 202 is sleeved on the outer side of the core column of the iron core 1, and a gap is left between the inner side wall of the low-voltage winding 202 and the core column of the iron core 1; wherein the high-voltage winding The group 201 is sleeved on the outside of the low-voltage winding 202, and a main channel 4 is left between the high-voltage winding 201 and the low-voltage winding 202; wherein the heat dissipation device 3 includes a high-voltage side heat-conducting layer 301, a low-voltage side heat-conducting layer 302 and a heat dissipation element 303; wherein the high-voltage side heat-conducting layer 301 is arranged on the inner and outer walls of the high-voltage winding 201; the low-voltage side heat-conducting layer 302 is arranged on the outer wall of the low-voltage winding 202; wherein the heat dissipation element 303 is arranged in the main channel 4 formed by the high-voltage winding 201 and the low-voltage winding 202. The present invention originally applies the enhanced heat dissipation technology to the technical field of epoxy cast dry-type transformers, adopts the enhanced heat dissipation technology to improve the heat dissipation efficiency of the main channel, fundamentally changes the heat dissipation mode of the epoxy cast dry-type transformer, and maximizes the heat dissipation capacity of the main channel 4, which can greatly reduce the temperature rise of the epoxy cast dry-type transformer. At the same time, it provides an original technical solution for the development of epoxy cast dry-type transformers in the direction of lightweight, miniaturization, high efficiency and energy saving.

[0042] The iron core 1 of the embodiment of the present invention is made of silicon steel sheets; wherein the upper clamp 102 includes a first fixing plate 102 and a first pull rod 104, the first fixing plate 102 is a planar structure, two first fixing plates 102 are provided, and the two first fixing plates 102 are arranged in parallel; the two first fixing plates 102 are connected by the first pull rod 104, when the iron core 1 is installed, the upper iron yoke of the iron core 1 away from the base is clamped and fixed by the two first fixing plates 102 and the first pull rod 104 of the upper clamp 102; wherein the lower clamp includes a second fixing plate 103 and a second pull rod, two second fixing plates are provided, and the two second fixing plates 103 are arranged in parallel, The second fixed plate 103 is provided with an upper flange and a lower flange at the top and bottom respectively, wherein the upper flange is provided with a fixed support at intervals, the fixed support is a bending structure, wherein the bending structure extends outward along the width direction of the upper flange, and a fixing frame 304 is provided on the fixed support, and the lower flange of the second fixed plate 103 is fixedly connected to the transformer base by bolts; wherein the bottom of the low-voltage winding 202 and the high-voltage winding 201 are fixed to the fixed support of the upper flange of the second fixed plate 103 by the fixing frame 304; when the iron core 1 is installed, the lower iron yoke of the iron core 1 is clamped and fixed by the two second fixed plates 103 and the second pull rod of the lower clamp. The first fixed plate 102 of the present design is a planar structure, which eliminates the structural form in the prior art that needs to be fixed to the upper clamp through a bending connection mechanism and a pad; at the same time, the present design fixes the low-voltage winding 202 and the high-voltage winding 201 by arranging a fixed support at the interval of the second fixed plate, which greatly reduces the influence of the upper clamp, the lower clamp and the connection structure on the heat dissipation of the transformer, and reduces the stray loss of the core clamp.

[0043] Specifically, the iron core 1 is mainly formed by stacking silicon steel sheets, the outer sides of the core columns of the three iron cores 1 are clamped by upper clamps and lower clamps, the first fixing plate 102 is a planar structure, and is provided with a first tie rod 104 and a hole for transformer wiring, the upper iron yoke of the iron core 1 is clamped by two first fixing plates 102 of the upper clamp, and the two first fixing plates 102 are tightened by a plurality of first tie rods 104. The second fixing plate 103 of the lower clamp is provided with an upper flange and a lower flange at the top and bottom, respectively, wherein the upper flange is provided with a bending structure at intervals, wherein the bending structure extends outwardly along the width direction of the upper flange for installing a support foot 3041 of the winding 2, the lower flange of the second fixing plate 103 is fixedly connected to the transformer base by bolts, the lower iron yoke is clamped by two second fixing plates 103 of the lower clamp, and the two second fixing plates 102 are tightened by a plurality of second tie rods, and the insulating member is installed at the contact portion between the iron core 1 and the first fixing plate 102 and the second fixing plate 103. The upper clamp 102 of the present invention adopts a pull rod structure and the lower clamp 103 adopts a bending structure, which reduces the influence of the pad position on the heat dissipation of the transformer on the one hand, and reduces the heat generated by the stray loss of clamping on the other hand.

[0044] The winding 2 is mounted on the iron core 1, and the entire winding 2 is mainly composed of a low-voltage winding 202 and a high-voltage winding 201. The low-voltage winding 202 is mounted on the iron core, and its inner side is adjacent to the core column of the iron core 1, and a certain gap is left between the iron core 1. The high-voltage winding 201 is mounted on the outer side of the low-voltage winding 202, and the inner side of the high-voltage winding 201 is adjacent to the outer side of the low-voltage winding 202, and a main air channel is left between the low-voltage winding 202, and a heat dissipation device 3 is arranged inside the high-voltage winding 201. The present invention is original in that the heat dissipation device is formed into an integrated structure by integral casting between the high-voltage winding 201 and the low-voltage winding 202, which not only reduces the difficulty of the transformer assembly process, but also ensures the consistency of the size of the main channel 4, thereby reducing the influence of the size deviation of the main channel 4 on the transformer impedance value and heat dissipation capacity.

[0045] The high-voltage side heat-conducting layer 301 of the embodiment of the present invention includes an inner heat-collecting layer 3012 and an outer heat-collecting layer 3011, wherein the outer heat-collecting layer 3011 is arranged on the outer wall of the high-voltage winding 201; wherein the inner heat-collecting layer 3012 is arranged on the inner wall of the high-voltage winding 201, and one side of the inner heat-collecting layer 3012 is adjacent to the main channel 4; wherein the heat dissipation device 3 also includes a heat-conducting column 306 and a heat-conducting sheet 305, wherein one side of the heat-conducting column 306 is arranged on the inner heat-collecting layer 3012, and the other end of the heat-conducting column 306 is connected to the outer heat-collecting layer 3011, and an installation groove is opened on the heat-conducting column; the heat-conducting sheet 305 is fixed by clamping the installation groove of the heat-conducting column 306.

[0046] The high-voltage side heat-conducting layer 301 and the low-voltage side heat-conducting layer 302 of the embodiment of the present invention are respectively arranged on the high-voltage winding 201 and the low-voltage winding 202 by means of insulating glue bonding or press-fitting.

[0047] The winding 2 of the embodiment of the present invention adopts the epoxy casting process, and the pad block structure is eliminated; wherein a plurality of heat-conducting columns 306 are provided, and the plurality of heat-conducting columns 306 are arranged at intervals along the circumference of the high-voltage winding 201 to form a heat-conducting layer, and the heat-conducting layer is arranged between each group of coils in the high-voltage winding 201; wherein one end of the heat-conducting sheet 305 is connected to the heat-conducting column 306, and the other end of the heat-conducting sheet 305 extends upward and is arranged circumferentially along the top surface of each group of coils in the high-voltage winding 201. The heat-conducting sheet 305 of the embodiment of the present invention is made of a high thermal conductivity material and is located between the wires in the high-voltage winding 201. On the one hand, it transfers the heat inside the high-voltage winding 201 to the heat-conducting column 306, and on the other hand, it adjusts the interlayer voltage of the high-voltage winding 201.

[0048] One side of the high-voltage inner heat-conducting layer 3012 is connected to the inner wall of the high-voltage winding 201, and the other side is connected to the heat dissipation element 303; one side of the low-voltage side heat-conducting layer 302 is connected to the outer wall of the low-voltage winding, and the other side of the low-voltage side heat-conducting layer 302 is connected to the heat dissipation element 303; and the high-voltage outer heat-conducting layer 3011 and the inner heat-collecting layer 3012 of the high-voltage winding 201, and the low-voltage side heat-conducting layer 302 and the low-voltage winding 202 are installed by vacuum impregnation or pressure impregnation, thereby reducing the enclosed air, thereby reducing the thermal resistance between the components, and improving the heat conduction efficiency.

[0049] The heat dissipation element 303 of the embodiment of the present invention includes a plurality of heat dissipation fins, each of which is arranged at equal intervals in the main channel 4 formed by the high-voltage winding 201 and the low-voltage winding 202, wherein the cross-sectional shape of the heat dissipation fin is rectangular, and the panel of the heat dissipation fin is arrayed with serrated protrusions, the thickness of the heat dissipation fin is not more than 3 mm, and the heat dissipation fin is made of a material with high thermal conductivity; the number of heat dissipation elements 303 is calculated by the following formula:

[0050] Wherein: S is the heat dissipation area of ​​the heat dissipation element 303, a is the comprehensive heat transfer coefficient, n is the number of the heat dissipation elements 303, P is the loss of the winding 2, τ is the average temperature rise, b is the surface heat dissipation coefficient of the heat dissipation element, and A is the surface area of ​​the winding.

[0051] The enhanced heat dissipation structure of the epoxy cast dry-type transformer of the embodiment of the present invention adopts a pull screw structure for the upper clamp and a fixed support for the lower clamp at intervals, which reduces the influence of the position of the upper pad on the heat dissipation of the transformer on the one hand, and reduces the heat generated by the stray loss of clamping on the other hand. The heat-conducting column 306 is made of high thermal conductivity material and is arranged between each group of coils in the high-voltage winding 201. Its height is the same as the width of the segment spacing of the high-voltage winding 201. On the one hand, it supports the coils of each segment of the high-voltage winding 201, and on the other hand, it guides the heat of the high-voltage winding 201 into the heat-conducting layer, so that the heat inside the winding is efficiently transferred to the high-voltage inner heat collection layer 3012 and the high-voltage outer heat collection layer 3011 to achieve the effect of heat dissipation.

[0052] The heat dissipation device 3 of the embodiment of the present invention is integrally cast with the high-voltage winding 201 and the low-voltage winding 202 to enhance the heat dissipation capacity of the main channel 4, and is composed of the winding 2, the heat dissipation element 303, and the reinforcing ribs;

[0053] There are n heat dissipation elements 303 in the main channel between the high-voltage winding 201 and the low-voltage winding 202 of the winding 2, where n is determined by the above formula; one end of the heat dissipation element 303 is cast as a whole with the inner heat collection layer of the high-voltage winding 201, and the other end is cast as a whole with the low-voltage winding 202; the reinforcing rib I is located at the upper end of the winding 2, is flush with the end surface of the winding 2, extends in the main channel 4 toward the heat dissipation element 303, and leaves a certain space with the heat dissipation element 303 to facilitate the flow of cooling medium. One end of the reinforcing rib is cast as a whole with the high-voltage winding 201, and the other end is cast as a whole with the low-voltage winding 202, and its height and width are determined according to the size of the winding; the reinforcing rib is located at the lower end of the winding 2, extends in the main channel 4 toward the heat dissipation element 303, and leaves a certain space with the heat dissipation element to facilitate the flow of cooling medium. The reinforcing rib II extends in the opposite direction of the main channel and is installed on the lower clamp 104 of the core 1. The height and width of the reinforcing ribs are determined according to the size of the winding 2 and the distance between the winding 2 and the iron core 1 .

[0054] A new heat dissipation method for an epoxy cast dry-type transformer adopts enhanced heat dissipation technology. A heat dissipation device 3 is added in a main channel 4 between a high-voltage winding 201 and a low-voltage winding 202 to enhance the heat dissipation efficiency of the main channel 4. The heat dissipation device 3 can be installed in the main channel 4 between the high-voltage winding 201 and the low-voltage winding 202, or can be integrally cast with the high-voltage winding 201 and the low-voltage winding 202.

[0055] The manufacturing process of the enhanced heat dissipation structure of the epoxy cast dry-type transformer of the present invention comprises the following steps:

[0056] Step A: Making a silicon steel sheet into an iron core 1;

[0057] Step B: installing the heat dissipation device 3 in the main channel 4 between the high voltage winding 201 and the low voltage winding 202;

[0058] Step C: The winding 2 provided with the heat dissipation device 3 is mounted on the iron core 1 to form a structure of an epoxy cast dry-type transformer, and the heat dissipation device 3 is used to enhance the heat dissipation of the main channel 4.

[0059] In step B of the present invention, the heat sink 3 and the high-voltage winding 201 and the low-voltage winding 202 are integrally cast, and reinforcing ribs are provided during the casting process. The present invention casts the high and low voltage windings together with the reinforced heat sink to form an integral structure with high mechanical strength. At the same time, reinforcing ribs are added inside to further enhance the structural strength of the transformer. During the casting process, the epoxy resin can fully fill the gap between the winding and the heat sink, improving the heat dissipation performance. It is suitable for some occasions that need to withstand greater mechanical stress, such as high-rise buildings, underground buildings, airports, transportation hubs, etc.; or occasions with higher requirements for heat dissipation performance, such as areas with large power loads; in addition, integral casting can usually complete the casting of multiple components at one time, with higher production efficiency.

[0060] In step B of the present invention, the winding 2 is first cast, and after the casting is completed, the heat sink 3 is fixed between the high-voltage winding 201 and the low-voltage winding 202 by the fixing frame 304. Specifically, a fixing frame 304 is arranged inside the winding 2, wherein the fixing frame 304 is mainly composed of a pad 3042 and a support leg 3041, wherein the pad 3042 is used for radial limiting of the lower ends of the high-voltage winding 201 and the low-voltage winding 202, and is composed of several pads distributed on the lower part of the winding 2, extending in the main channel 4 in the direction of the heat dissipation element 303, leaving a certain space with the heat dissipation element 303, so as to facilitate the flow of the cooling medium; wherein the support leg 3041 is used for radial limiting of the lower ends of the high-voltage winding 201 and the low-voltage winding 202 and the axial support of the end, and is composed of several pads distributed on the pad 3042, extending in the main channel 4 in the direction of the heat dissipation element 303, leaving a certain space with the heat dissipation element 303, so as to facilitate the flow of the cooling medium. The supporting foot 3041 extends in the opposite direction of the main channel 4 and is installed on the lower clamp 104 of the core 1. The present invention first casts the high-voltage winding 201 and the low-voltage winding 202, and then casts the heat sink 3, and fixes the heat sink 3 to the inside of the main channel 4 formed by the high-voltage winding 201 and the low-voltage winding 202 through the fixing frame 304. The casting process is relatively flexible, and the quality of different components can be controlled separately. The connection between the heat sink 3, the high-voltage winding 201 and the low-voltage winding 202 is achieved through the fixing frame 304, and the structure is relatively simple. It is suitable for some occasions where local repairs or replacement of parts of the transformer are required, there are certain restrictions on production conditions, and different parts need to be handled separately.

[0061] When installing the heat dissipation device 3 of the embodiment of the present invention, the heat dissipation device 3 is first installed in the main channel 4 between the high-voltage winding 201 and the low-voltage winding 202, and the generation of enclosed air on the joint surface between the three is avoided during the installation of the heat dissipation device 3; then the winding 2 with the heat dissipation device 3 installed is mounted on the iron core 1 to complete the overall assembly of the dry-type transformer.

[0062] The heat dissipation device 3 of the present invention is integrally cast with the high-voltage winding 201 and the low-voltage winding 202. The specific sequence is to first wind the low-voltage winding 202, then install the airway strip on the outer side of the low-voltage winding 202, and then wind the high-voltage winding 201 on the outer side of the airway strip; then perform epoxy casting treatment on the winding 2; and finally, put the winding 2 on the iron core 1.

[0063] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. An enhanced heat dissipation structure of an epoxy cast dry-type transformer, characterized in that: It comprises an iron core (1), a winding (2), a base and a heat sink (3); A lower clamping piece for clamping a lower iron yoke of the iron core (1) is fixedly connected to the top of the base, and an upper iron yoke at an end of the iron core (1) away from the base is clamped and fixed by the upper clamping piece; The winding (2) comprises a low-voltage winding (202) and a high-voltage winding (201); the low-voltage winding (202) is sleeved on the outside of a core column of the iron core (1), and a gap is left between the inner wall of the low-voltage winding (202) and the core column of the iron core (1); the high-voltage winding (201) is sleeved on the outside of the low-voltage winding (202), and a main channel (4) is left between the high-voltage winding (201) and the low-voltage winding (202); The heat dissipation device (3) comprises a high-voltage side heat-conducting layer (301), a low-voltage side heat-conducting layer (302) and a heat dissipation element (303); the high-voltage side heat-conducting layer (301) is arranged on the inner wall and the outer wall of the high-voltage winding (201); the low-voltage side heat-conducting layer (302) is arranged on the outer wall of the low-voltage winding (202); and the heat dissipation element (303) is arranged in a main channel (4) formed by the high-voltage winding (201) and the low-voltage winding (202).

2. The enhanced heat dissipation structure of the epoxy cast dry-type transformer according to claim 1, characterized in that: The high-voltage side heat-conducting layer (301) comprises an inner heat-collecting layer (3012) and an outer heat-collecting layer (3011), wherein the outer heat-collecting layer (3011) is arranged on the outer side wall of the high-voltage winding (201); the inner heat-collecting layer (3012) is arranged on the inner side wall of the high-voltage winding (201), and one side of the inner heat-collecting layer (3012) is adjacent to the main channel (4); the heat dissipation device (3) further comprises a heat-conducting column (306) and a heat-conducting sheet (305), wherein one side of the heat-conducting column (306) is arranged on the inner heat-collecting layer (3012), and the other end of the heat-conducting column (306) is connected to the outer heat-collecting layer (3011), and an installation groove is provided on the heat-conducting column; the heat-conducting sheet (305) is fixedly connected to the installation groove of the heat-conducting column (306).

3. The enhanced heat dissipation structure of the epoxy cast dry-type transformer according to claim 2, characterized in that: The winding (2) adopts an epoxy casting process and eliminates a pad pressure block structure; a plurality of heat-conducting columns (306) are provided, and the plurality of heat-conducting columns (306) are arranged at intervals along the circumference of the high-voltage winding (201) to form a heat-conducting layer, and the heat-conducting layer is arranged between each group of coils in the high-voltage winding (201); one end of the heat-conducting sheet (305) is connected to the heat-conducting column (306), and the other end of the heat-conducting sheet (305) extends upward and is arranged circumferentially along the top surface of each group of coils in the high-voltage winding (201).

4. The enhanced heat dissipation structure of the epoxy cast dry-type transformer according to claim 3, characterized in that: The iron core (1) is made of silicon steel sheets; the upper clamp (102) comprises a first fixing plate (102) and a first pull rod (104); the first fixing plate (102) is a planar structure; two first fixing plates (102) are provided, and the two first fixing plates (102) are arranged in parallel; the two first fixing plates (102) are connected by a first pull rod (104); when the iron core (1) is installed, the upper iron yoke of the iron core (1) away from the base is clamped and fixed by the two first fixing plates (102) and the first pull rod (104) of the upper clamp (102); The lower clamp comprises a second fixing plate (103) and a second pull rod, two second fixing plates are provided, and the two second fixing plates (103) are arranged in parallel, the top and bottom of the second fixing plate (103) are respectively provided with an upper flange and a lower flange, wherein the upper flange is provided with a fixing support at intervals, the fixing support is a bending structure, wherein the bending structure extends outward along the width direction of the upper flange, a fixing frame (304) is provided on the fixing support, and the lower flange of the second fixing plate (103) is fixedly connected to the transformer base by bolts; the bottom of the low-voltage winding (202) and the high-voltage winding (201) are fixed to the fixing support of the upper flange of the second fixing plate (103) by the fixing frame (304); when the iron core (1) is installed, the lower iron yoke of the iron core (1) is clamped and fixed by the two second fixing plates (103) and the second pull rod of the lower clamp.

5. The enhanced heat dissipation structure of the epoxy cast dry-type transformer according to claim 4, characterized in that: The high-voltage side heat-conducting layer (301) and the low-voltage side heat-conducting layer (302) are respectively arranged on the high-voltage winding (201) and the low-voltage winding (202) by means of insulating glue bonding or press-fitting.

6. The enhanced heat dissipation structure of the epoxy cast dry-type transformer according to claim 5, characterized in that: The heat dissipation element (303) comprises a plurality of heat dissipation fins, each of which is arranged at equal intervals in a main channel (4) formed by a high-voltage winding (201) and a low-voltage winding (202), the cross-sectional shape of the heat dissipation fin is rectangular, a panel of the heat dissipation fin is provided with sawtooth-shaped protrusions in an array, the thickness of the heat dissipation fin is not greater than 3 mm, and the heat dissipation fin is made of a material with high thermal conductivity; the number of heat dissipation elements (303) is calculated by the following formula: In the formula, S is the heat dissipation area of ​​the heat dissipation element, a is the comprehensive heat transfer coefficient, n is the number of heat dissipation elements (303), P is the loss of the winding (2), τ is the average temperature rise, b is the surface heat dissipation coefficient of the heat dissipation element (303), and A is the surface area of ​​the winding.

7. The manufacturing process of the enhanced heat dissipation structure of the epoxy cast dry-type transformer according to claim 6, characterized in that: The following steps are involved: Step A: Making a silicon steel sheet into an iron core (1); Step B: installing the heat dissipation device (3) in the main channel (4) between the high-voltage winding (201) and the low-voltage winding (202); Step C: The winding (2) provided with the heat dissipation device (3) is mounted on the iron core (1) to form a structure of an epoxy cast dry-type transformer, and the heat dissipation device (3) is used to enhance the heat dissipation of the main channel (4).

8. The manufacturing process according to claim 7, characterized in that: In step B, the heat sink (3) and the high-voltage winding (201) and the low-voltage winding (202) are integrally cast, and reinforcing ribs are provided during the casting process.

9. The manufacturing process according to claim 7, characterized in that: In step B, the winding (2) is first cast, and after the casting is completed, the heat sink (3) is fixed between the high-voltage winding (201) and the low-voltage winding (202) by a fixing frame (304), and then the heat sink (3) is cast.

Images