CN110767419A - An evaporative cooling core transformer - Google Patents

Abstract

The invention belongs to the technical field of transformers, and in particular relates to an evaporative cooling core type transformer. In order to solve the problem that the existing layered winding structure can only form cooling channels in the axial direction and the cooling capacity of the winding is insufficient, the evaporative cooling core transformer proposed by the present invention includes an iron core, which is wound in turn from the inside to the outside along the radial direction of the iron core. There are low-voltage windings and high-voltage windings. The low-voltage windings and high-voltage windings are arranged in a segmented coil cake structure along the axial direction of the iron core. The turns of high-voltage windings are composed together; a plurality of spacers are arranged between two adjacent coil cakes, and the two adjacent spacers are used to form a radial flow of cooling medium between the two adjacent coil cakes. 's flow channel. In the present invention, by arranging the transformer coils in sections, the cooling medium can flow radially between two adjacent coil cakes, thereby greatly improving the cooling capacity of the transformer coils.

Description

An evaporative cooling core transformer

technical field

The invention belongs to the technical field of transformers, and in particular relates to an evaporative cooling core type transformer.

Background technique

A transformer is a device that uses the principle of electromagnetic induction to change the AC voltage. Transformers generate heat during operation, and heat dissipation is a key factor restricting the performance of transformers. The prior art employs a transformer oil cooling system. The transformer oil cooling system has the following problems: First, the viscosity of the transformer oil is too high (10-15cs), the fluidity is poor, and the heat exchange efficiency is low; The specific heat of transformer oil is low (1.8kJ/kg), which is about 40% of water, and the heat capacity is weak, which makes the weight and structure of the transformer large.

The core of the core transformer is surrounded by windings. At present, the coiled iron core traction transformer coil is wound with high and low voltage coils. Between the low-voltage coil and the high-voltage coil, a support member composed of a paper tube and a stay is arranged. This layered winding structure can only form cooling channels in the axial direction, and the cooling capacity of the windings is insufficient.

Therefore, the present invention proposes an evaporative cooling core transformer to solve the above problems.

SUMMARY OF THE INVENTION

In order to solve the above problems in the prior art, that is, in order to solve the problem that the existing layered winding structure can only form cooling channels in the axial direction, and the cooling capacity of the winding is insufficient, the present invention provides a core-type winding suitable for adopting evaporative cooling technology. Transformer, the core-type transformer includes an iron core, a low-voltage winding and a high-voltage winding are sequentially wound from the inside to the outside along the radial direction of the iron core, and the low-voltage winding and the high-voltage winding are arranged in sections along the axial direction of the iron core. type coil pie structure, each coil pie is composed of several turns of low-voltage windings and several turns of high-voltage windings that are sequentially wound from the inside to the outside along the radial direction of the iron core; A plurality of spacers, two adjacent spacers are used to form a flow channel for the radial flow of the cooling medium between the two adjacent coil cakes.

In a preferred embodiment of the above-mentioned evaporative cooling core transformer, a support bar is provided between the high-voltage winding and the low-voltage winding, and the support bar is used to form a space between the high-voltage winding and the low-voltage winding for The channel through which the cooling medium flows.

In a preferred embodiment of the above-mentioned evaporative cooling core transformer, the insulating distance between the high voltage winding and the low voltage winding is matched with the thickness of the support bar, and thus the support bar is fixed by extrusion between the high voltage winding and the low voltage winding.

In a preferred embodiment of the above-mentioned evaporative cooling core type transformer, the core type transformer further comprises an iron core sleeve, the iron core sleeve is located between the low-voltage winding and the iron core and sleeved on the iron core upper; an iron core corner protector is provided between the iron core sleeve and the iron core, and the iron core corner protector is used to support the iron core sleeve so that the iron core sleeve and the iron core can be connected A flow channel for the flow of the cooling medium is formed therebetween.

In a preferred embodiment of the above-mentioned evaporative cooling core transformer, the core sleeve is provided with a plurality of dovetail grooves in the axial direction, and the spacer between two adjacent coil cakes can be along the axis of the core sleeve. The dovetail groove is radially abutted to form an axial flow gap for cooling the working medium, and the axial flow gap is used to communicate the flow channel between each adjacent two coil cakes.

In a preferred embodiment of the above-mentioned evaporative cooling core transformer, a plurality of long through holes are formed on the core sleeve in the part between two adjacent dovetail grooves, and the long through holes are used for cooling quality circulation.

In a preferred embodiment of the above-mentioned evaporative cooling core type transformer, the material of the iron core sleeve is FRP.

In the above preferred embodiment of the evaporative cooling core type transformer, the cross section of the iron core corner protector is L-shaped.

In a preferred embodiment of the above evaporative cooling core transformer, the cooling medium is an insulating organic liquid with high latent heat of evaporation.

In a preferred embodiment of the above-described evaporatively cooled core transformer, the core transformer is a traction transformer used as a rail vehicle.

By arranging the transformer coils in sections, the invention enables the cooling medium to flow radially between two adjacent coil cakes, thereby increasing the contact area between the cooling medium and the transformer coil, and greatly improving the efficiency of the transformer. Cooling capacity of the coil. In the invention, an iron core sleeve is also arranged on the iron core, so as to provide more flow passage gaps for the cooling medium, so as to realize sufficient cooling of the transformer coil. In addition, the cooling medium of the present invention adopts insulating organic liquid with high latent heat of evaporation. Compared with traditional forced oil cooling, the cooling medium is non-flammable and non-explosive, completely eliminating the risk of flammability of transformer oil, and greatly improving system-level safety and reliability. sex.

Description of drawings

Fig. 1 is the sectional schematic diagram of the evaporative cooling core type transformer of the present invention;

Fig. 2 is the side view schematic diagram of the evaporative cooling core type transformer of the present invention;

Fig. 3 is the enlarged view of A area in Fig. 2;

Fig. 4 is the structural representation of the iron core sleeve of the evaporative cooling core type transformer of the present invention;

Fig. 5 is the structural representation of the iron core angle protector of the evaporative cooling core type transformer of the present invention;

FIG. 6 is a schematic structural diagram of a gasket of an evaporative cooling core transformer according to an embodiment of the present invention.

Description of drawings: 1-high voltage winding; 2-low voltage winding; 3-iron core; 4-iron core sleeve; 41-dovetail slot; 42-long through hole; 5-iron core corner protector; 6-support bar; 7 -Cushion strips.

Detailed ways

In order to make the embodiments, technical solutions and advantages of the present invention more obvious, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some of the embodiments of the present invention, not all of them. Example. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principle of the present invention, and are not intended to limit the protection scope of the present invention.

Referring first to FIG. 1 , FIG. 1 is a schematic cross-sectional view of the evaporative cooling core type transformer of the present invention. As shown in FIG. 1 , the core-type transformer of the present invention includes an iron core 3 , and a low-voltage winding 2 and a high-voltage winding 1 are sequentially wound from the inside to the outside along the radial direction of the iron core 3 . Axially arranged into a segmented coil cake structure, each coil cake is composed of several turns of low-voltage windings 2 and several turns of high-voltage windings 1 wound from the inside to the outside along the radial direction of the iron core 3 . In addition, a plurality of spacers 7 are arranged between two adjacent coil cakes, and the two adjacent spacers 7 are used to form a flow for cooling the working medium to flow radially between the two adjacent coil cakes. road. The cooling medium can be an insulating organic liquid with a high latent heat of vaporization, such as an insulating organic liquid with a high latent heat of vaporization with a boiling point of 60-80°C.

According to the core-type transformer structure designed in the present invention, the transformer coils are arranged in sections. Specifically, several turns of low-voltage windings 2 and several turns of high-voltage windings 1 are wound from the inside to the outside along the radial direction of the iron core 3 to form a coil cake. In this way, the entire low-voltage winding 2 and high-voltage winding 1 can form many independent coils. coil pie. For example, along the radial direction of the iron core 3, 50 turns of low-voltage winding 2 and 100 turns of high-voltage winding 1 are sequentially wound from the inside to the outside, and every 1 turn of low-voltage winding 2 and every 2 turns of high-voltage winding 1 form a coil cake, then the entire low-voltage winding 2 and high voltage winding 1 can form 50 independent coil cakes. This example is only for the convenience of understanding the arrangement of the coil pie, and is not intended to limit the protection scope of the present invention. As mentioned above, it can also be understood that the transformer coil adopts a segmented arrangement, and a plurality of coil cakes are sequentially arranged along the axial direction of the iron core 3 .

Since a plurality of spacers 7 are arranged between two adjacent coil cakes, the two adjacent coil cakes can be effectively separated. As an example, referring to Fig. 1 and Fig. 2 and Fig. 6, Fig. 2 is a schematic side view of an evaporative cooling core transformer of the present invention; Fig. 6 is a schematic structural diagram of a gasket of an evaporative cooling core transformer according to an embodiment of the present invention . As shown in Figure 1, Figure 2 and Figure 6, the gasket 7 is a long strip, one end of which is close to the outer edge of the high-voltage coil 1, and the other end passes through the low-voltage coil 2, thereby separating two adjacent coil cakes. As an example, the spacer 7 is arranged perpendicular to the axis of the iron core 3, so that between two adjacent coil cakes, a diameter for cooling working medium can be formed between every two adjacent spacers 7 It can effectively increase the contact area between the cooling medium and the transformer coil and improve the heat exchange efficiency.

Referring back to FIG. 1 , a support bar 6 is provided between the high-voltage winding 1 and the low-voltage winding 2 , and the support bar 6 is used to form a flow channel for the cooling medium to flow between the high-voltage winding 1 and the low-voltage winding 2 . The insulating distance between the high-voltage winding 1 and the low-voltage winding 2 matches the thickness of the support bar 6 , and thus the support bar 6 is fixed between the high-voltage winding 1 and the low-voltage winding 1 by pressing. In this way, the cooling medium can flow along the flow channel, thereby further effectively increasing the contact area between the cooling medium and the transformer coil, and improving the heat exchange efficiency. The length-width ratio of the cross-sectional end face of the support bar 6 should not be too large. The specific arrangement position and quantity are determined by the mechanical strength requirements of the high-voltage winding 2 and the low-voltage winding 1, and should not affect the flow of the cooling medium.

In a specific embodiment, as shown in FIGS. 1 and 2 , the core-type transformer of the present invention further includes an iron core sleeve 4 (as an example, the iron core sleeve 4 can be made of glass fiber reinforced plastic), an iron core sleeve The barrel 4 is located between the low-voltage winding 2 and the iron core 3 and is sleeved on the iron core 3 . Further, between the iron core sleeve 4 and the iron core 3, an iron core protector 5 is provided, and the iron core protector 5 is used to support the iron core sleeve 4 to form a space between the iron core sleeve 4 and the iron core 3. The flow channel for the cooling medium to flow. In order to illustrate the structure more clearly, referring to Fig. 3-5 below, Fig. 3 is an enlarged view of the area A in Fig. 2; Fig. 4 is a schematic diagram of the structure of the iron core sleeve of the evaporative cooling core transformer of the present invention; A schematic diagram of the structure of the iron core corner protector of the evaporative cooling core type transformer of the present invention.

As shown in Figure 3-5, the cross section of the iron core protector 5 is L-shaped, which is clamped at the corners of the iron core 3, and the iron core sleeve 4 is cylindrical. When placed on the iron core 3 , the outer corner of the iron core protector 5 is in contact with the sleeve of the iron core 4 and supports the iron core sleeve 4 . In this way, a flow channel for cooling the working medium can be formed between the iron core sleeve 4 and the iron core 3 . Thereby, the contact area between the cooling medium and the transformer coil is further increased, and the heat exchange efficiency is improved.

In a more specific embodiment, as shown in FIG. 4 , the core sleeve 4 is provided with a plurality of dovetail grooves 41 along the axial direction. In the case where the iron core sleeve 4 is sleeved on the iron core 3, the low voltage winding 2 and the high voltage winding 1 are sequentially wound from the inside to the outside along the radial direction of the iron core 3, which is equivalent to the radial direction of the iron core sleeve 4 from the inside to the outside. A low-voltage winding 2 and a high-voltage winding 1 are wound on the outside in turn. In this way, the spacer strip 7 between two adjacent two coil cakes can abut against the dovetail groove 41 in the radial direction of the core sleeve 4 to form an axial flow gap for cooling the working medium. The axial flow gap is used to communicate the flow channels between each adjacent two coil cakes. In other words, the cooling medium can flow through each coil cake in turn in the axial direction along the dovetail groove 41 , that is, the flow channel between each adjacent two coil cakes is connected. Thereby, the contact area between the cooling medium and the transformer coil is further increased, and the heat exchange efficiency is improved.

Continuing to refer to FIG. 4 , on the core sleeve 4 , a portion between two adjacent dovetail grooves 41 is provided with a plurality of long through holes 42 , and the long through holes 42 are used for the circulation of the cooling medium. Those skilled in the art can understand that the long through hole 42 can allow the cooling medium to pass freely, and the installation position of the iron core protector 5 should not overlap with the long through hole as much as possible, so as not to affect the flow of the cooling medium.

As an example, the core transformer may be used as a traction transformer for a rail vehicle, eg mounted on the underbody of the vehicle.

By arranging the transformer coils in sections, the invention enables the cooling medium to flow radially between two adjacent coil cakes, thereby increasing the contact area between the cooling medium and the transformer coil, and greatly improving the efficiency of the transformer. Cooling capacity of the coil. In the invention, an iron core sleeve is also arranged on the iron core, so as to provide more flow passage gaps for the cooling medium, so as to realize sufficient cooling of the transformer coil. In addition, the cooling medium of the present invention adopts insulating organic liquid with high latent heat of evaporation. Compared with traditional forced oil cooling, the cooling medium is non-flammable and non-explosive, completely eliminating the risk of flammability of transformer oil, and greatly improving system-level safety and reliability. sex.

So far, the technical solutions of the present invention have been described with reference to the preferred embodiments shown in the accompanying drawings, however, those skilled in the art can easily understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims (10)

1. An evaporation cooling core type transformer, which comprises an iron core, and a low-voltage winding and a high-voltage winding are sequentially wound from inside to outside along the radial direction of the iron core, and is characterized in that,

the low-voltage winding and the high-voltage winding are arranged into a segmented coil cake structure along the axial direction of the iron core, and each coil cake consists of a plurality of turns of low-voltage winding and a plurality of turns of high-voltage winding which are sequentially wound from inside to outside along the radial direction of the iron core;

and a plurality of cushion strips are arranged between two adjacent coil cakes, and the two adjacent cushion strips are used for forming a flow channel for radial flow of the cooling working medium between the two adjacent coil cakes.

2. The evaporative cooling core transformer of claim 1, wherein a support bar is disposed between the high voltage winding and the low voltage winding, the support bar being configured to form a flow channel between the high voltage winding and the low voltage winding for the flow of cooling medium.

3. The evaporative cooling core transformer of claim 2, wherein the insulation distance between the high voltage winding and the low voltage winding matches the thickness of the support bar and thereby compressively secures the support bar between the high voltage winding and the low voltage winding.

4. The evaporative cooling core transformer of claim 2, further comprising a core sleeve positioned between the low voltage winding and the core and sleeved over the core;

the iron core sleeve is provided with an iron core angle bead between the iron core sleeve and the iron core, and the iron core angle bead is used for supporting the iron core sleeve so that a flow channel for cooling working medium flowing is formed between the iron core sleeve and the iron core.

5. The evaporative cooling core transformer of claim 4, wherein the core sleeve has a plurality of dovetail slots formed therein in an axial direction,

the filler strip between two adjacent coil cakes can be abutted against the dovetail groove along the radial direction of the iron core sleeve to form an axial flow gap for cooling working media,

the axial flow gap is used for communicating the flow channel between each two adjacent coil cakes.

6. The evaporative cooling core type transformer according to claim 5, wherein a plurality of through holes are formed in the core sleeve at a portion between two adjacent dovetail grooves, and the through holes are used for circulation of a cooling medium.

7. The evaporative cooling core transformer of claim 6, wherein the core sleeve is formed of glass reinforced plastic.

8. The evaporative cooling core transformer according to any of claims 4 to 7, wherein the core back angle is L-shaped in cross section.

9. The evaporative cooling core transformer of any of claims 1 to 7, wherein the cooling working medium is an insulating organic liquid of high latent heat of evaporation.

10. The evaporative cooling core transformer according to any of claims 1 to 7, wherein the core transformer is a traction transformer for use as a rail vehicle.

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