KR20120004367U - Method for cooling a coil coil cooling system and liquid cooled coil - Google Patents

Abstract

In the method the cooling element 102 is arranged in connection with the coil 100 and the cooling liquid is guided to flow through the cooling element. The cooling elements are arranged in connection with the coil so that the flow path of the cooling liquid does not form a uniform ring around the coil or around the individual conductor wires of the coil. The cooling system comprises at least three cooling elements, the cooling elements being located around the coil so that the distance between adjacent cooling elements is essentially the same. The cooling element may be located outside the coil in contact with the outer surface 122 of the coil, inside the coil in contact with the inner surface 120 of the coil, or within the coil between the overlapped conductor wires or foil layers of the coil. The flow path of the cooling liquid includes a cooling channel formed inside the cooling element, a first flow tube 112a for guiding the cooling liquid to the cooling channel, and a second flow tube 112b for guiding the cooling liquid out of the cooling channel. . The face surfaces 124, 126 of the cooling element lying on the inner or outer surface of the coil can be bent. The coil to be cooled may be a choke or a coil of a transformer.

Description

COIL COOLING METHOD, COIL COOLING SYSTEM, AND LIQUID COOLING COIL {METHOD FOR COOLING A COIL, COIL COOLING SYSTEM AND LIQUID COOLED COIL}

The present invention relates to a method for cooling a coil, in which the cooling element is arranged in connection with the coil and cooling liquid is guided to flow along the flow path through the cooling element. The present invention also relates to a cooling system with a liquid circulation for cooling the coil and a liquid cooling coil.

Inductive components such as transformers and chokes have an insulated coil through which current flows. There may be an iron core in the center of the coil, or the coil may have an air core. The resistance of the coil heats the coil. In particular, very high amounts of heat are generated in high current induction components. In order to keep the coil in the optimum operating temperature range specified therein, the coil needs to be cooled during use.

Several cooling systems with liquid circulation have been developed for cooling transformers and chokes. A liquid cooling choke is known from patent publication FI 118397 B, which comprises a core of the choke and a coil around the core. The core of the choke is divided into at least two parts, the at least two parts being adapted to a cooling profile through which one or more travel paths of the cooling liquid pass.

Methods and systems for cooling a transformer are known from patent publication US Pat. No. 6,157,282. A coil is formed in this manner, through which one or more channels are guided in the longitudinal direction of the coil. The end of the channel is connected with a tube to form a closed flow path for the cooling liquid. The flow path may have a heat exchanger for cooling the cooling liquid. In this solution, cooling channels are formed in the coil, which complicates the structure of the inductive component and makes its construction difficult. In addition, the cooling surface area of the cooling channel is small, so that the cooling effect is kept low.

Patent publication EP 068055 A1 shows a transformer in which part of the conductor turn of the coil is hollow. The coil is cooled by circulating a cooling liquid along the hollow conductor. In this solution, a voltage is induced in the cooling liquid, so that the electrically conductive liquid cannot be used as the cooling liquid. Thus, electrically nonconductive liquids are used in the cooling system, or the device must be equipped with a separate voltage remover for the cooling liquid.

It is an object of the present invention to provide a novel method for a cooling coil, a coil cooling system, and a liquid cooling coil, which can be used to greatly reduce the disadvantages and defects associated with the prior art.

The object of the present invention is achieved by a method, a cooling system and a coil, characterized in that provided in the independent claims. Some advantageous embodiments of the invention are provided in the dependent claims.

The present invention relates to a method for a cooling coil, such as a coil of a choke or a transformer. In the method at least three cooling elements are arranged in connection with the coil and the cooling liquid is guided to flow along the flow path through the cooling elements. The flow path includes at least one cooling channel formed in the cooling element, the cooling channel having a first opening for inflow of the cooling liquid and a second opening for the outflow of the cooling liquid. . The heat generated in the coil is thus transferred first by the conduction to the cooling element and into the cooling liquid flowing through the cooling element. In this method the cooling elements are arranged in connection with the coil so that the flow path of the cooling liquid does not form a uniform ring around the coil or around the individual conductor wires of the coil. Thus, even if an electrically conductive liquid such as tap water is used as the cooling liquid, no large voltage is generated in the cooling liquid.

Three or more cooling elements are used in the method according to the present invention in order to allow the coil to cool evenly in its various parts. The cooling elements are located around the coil, so that the distance between adjacent cooling elements is basically the same.

In an advantageous embodiment of the method according to the present invention, at least part of the cooling element is located outside of the coil with respect to the outer surface of the coil.

In an advantageous embodiment of the method according to the present invention, at least part of the cooling element is located inside of the coil with respect to the inner surface of the coil.

In an advantageous embodiment of the method according to the present invention, at least a part of the cooling element is located inside the coil between the overlapping conductor wires or foil layers of the coil.

A cooling system using liquid circulation according to the present invention for cooling a coil comprises at least three cooling elements to be arranged in connection with the coil and a flow path for the cooling liquid to circulate the cooling liquid through the cooling elements. The flow path includes at least one cooling channel formed inside the cooling element, the cooling channel having a first opening for the inlet of the cooling liquid and a second opening for the outflow of the cooling liquid. The cooling element of the cooling system can be located in connection with the coil to be cooled so that the flow path of the cooling liquid does not form a uniform ring around the coil or around the individual conductor wires of the coil.

In an advantageous embodiment of the cooling system according to the present invention, the first opening of the cooling channel is at the first end surface of the cooling element and the second opening of the cooling channel is at the second end surface of the cooling element. The cooling channel is advantageously a straight hole leading from the first end surface of the cooling element to the second end surface of the cooling element.

In an advantageous embodiment of the cooling system according to the present invention, the cooling element comprises at least two cooling channels. Advantageously, the cooling channels of the cooling elements are essentially parallel.

In an embodiment of the cooling system according to the present invention, the first opening and the second opening of the cooling channel are on the same end surface.

In an advantageous embodiment of the cooling system according to the present invention, the flow path of the cooling liquid comprises a first flow tube for guiding the cooling liquid into the cooling channel, a second flow tube for guiding the cooling liquid out of the cooling channel, and a bypass manifold ( bypass manifold, the flow tube being connected.

In an advantageous embodiment of the cooling system according to the present invention, the cooling element has at least one curved first side surface, which first side surface can lie on the inner surface of the coil.

The radius of curvature of the surface of the first face of the cooling element is generally 25-500 mm, advantageously 50-250 mm, particularly advantageously 150-200 mm. The width of the cooling element is generally 30-200 mm. If the radius of curvature of the first surface surface is chosen to be essentially the same as the radius of curvature of the inner surface of the coil, heat is efficiently transferred from the coil to the cooling element.

An advantageous embodiment of the cooling system according to the present invention has at least one curved first side surface, which second side surface can lie on the outer surface of the coil. The radius of curvature of the surface of the second face of the cooling element is generally 25-500 mm, advantageously 50-250 mm, particularly advantageously 150-200 mm.

Both side surfaces of the cooling element can be bent. The radius of curvature of the first and second face surfaces may be equally large or of different sizes. This embodiment of the cooling element is suitable for installation inside a coil between overlapping coil wires or foil layers.

The liquid cooling coil according to the present invention comprises at least three cooling elements using liquid circulation and a flow path for the cooling liquid for circulating the cooling liquid through the cooling elements. The flow path includes at least one cooling channel formed inside the cooling element, the cooling channel having a first opening for the inlet of the cooling liquid and a second opening for the outflow of the cooling liquid. The flow path of the cooling liquid does not form a uniform ring around the coil or around the individual conductor wires of the coil. The liquid cooling coil is advantageously a coil of a choke or a transformer.

An advantage of the present invention is that the cooling of the coil can thereby be handled efficiently in the entire coil area.

A further advantage of the present invention is that no voltage is induced in its cooling liquid. Thus, electrically conductive liquids such as tap water can be used as cooling liquid in the present invention.

An advantage of the cooling system according to the present invention is that the cooling system is structurally simple, small in size and low in mass. The small size and mass allow the use of the cooling system in many different usage situations.

A further advantage of the cooling system according to the present invention is that the cooling system can be located entirely outside the structure of the coil. Thus, the cooling system does not require any structural change in the coil itself.

The present invention provides a novel method for a cooling coil, a coil cooling system, and a liquid cooling coil, which has the effect of greatly reducing the disadvantages and defects associated with the prior art.

In the following, the present invention will be described in detail. In the detailed description, reference is made to the following accompanying drawings.
1a shows as an example a cooling system according to the present invention as shown obliquely above;
FIG. 1B shows the cooling system of FIG. 1A shown from above in the longitudinal axis of the coil; FIG.
1C shows an individual cooling element of the cooling system of FIG. 1A, shown obliquely from above.
2a shows, as an example, an advantageous embodiment of the cooling system according to the present invention shown above, in the longitudinal axis direction of the coil;
2b shows, as an example, a second advantageous embodiment of a cooling system according to the present invention, shown above in the longitudinal axis direction of the coil;
3a shows, by way of example, an advantageous embodiment of a cooling element of the cooling system according to the present invention as shown obliquely from the front.
3b shows, as an example, a second advantageous embodiment of a cooling element of the cooling system according to the present invention as shown obliquely from the front.
4a-4d show some advantageous embodiments of the cooling elements of the cooling system located in connection with the coils.
5 shows as an example a cooling element of a cooling system according to the present invention as shown obliquely above.

FIG. 1a shows as an example a cooling system according to the present invention shown obliquely from above, and FIG. 1b shows it from above. The coil 100 to be cooled is composed of one or more coil wires or foil layers, with the necessary insulation therebetween. The coil wire or foil layer forms a tube-like structure, which has an inner surface 120 and an outer surface 122. There is an open cylindrical space in the center of the coil, there may be a coil core (ferritic coil core) in the cylindrical space. The structure of the coil is generally known in the art and therefore will not be described further herein.

Around the coil are four elongated cooling elements 102. The cooling elements are arranged symmetrically around the coil so that their longitudinal axis is essentially parallel to the longitudinal axis of the coil. In FIG. 1, the cooling element is a part, the cross section of which is rectangular, ie, the first face surface 124 and the second face surface 126, which are two opposite face surfaces, and two opposite edges. It has an edge surface (FIG. 1B). The cooling element is positioned to be connected with the coil so that the first face surface 124 of the cooling element lies on the outer surface of the coil. Thus, heat generated in the coil can be transferred from the coil to the cooling element via conduction. Cooling channel 104 enters into the cooling element, which acts as a flow path for the cooling liquid (FIG. 1C).

Each cooling element is connected with two flow tubes 112a and 112b to a bypass manifold 110 belonging to the cooling system. The bypass manifold has an inlet connection 114, whereby cooling liquid is directed to the bypass manifold and the outlet connection 116, and heating from the cooling element through the outlet connection. Cooled liquid is guided out of the bypass manifold. The heated cooling liquid is cooled back to the appropriate temperature in a heat exchanger that can be attached to the cooling system, after which the cooling liquid is returned to the bypass manifold. Since the heat exchanger does not belong to the scope of the present invention, it is not described in more detail herein.

1c shows the individual cooling elements of the cooling system as shown obliquely above. The cooling channel 104 passes through the cooling element in a U-shaped path starting at the first end surface 118 and ending at the first end surface. Within the cooling element the cooling channel is close to the second end surface. At the first end surface 118 pointing upward in FIG. 1C of the cooling element, there are openings 106a and 106b of the cooling channel, the second ends of the flow tubes being connected to each other. The cross-sectional shape of the cooling channel is chosen such that its flow resistance to the cooling liquid is as small as possible. Cooling elements are made of some materials, such as aluminum, which conduct heat well. Thus, the heat conducting from the coil to the cooling element is easily transferred from the cooling element to the cooling liquid flowing through the cooling channel.

The cooling element shown in FIG. 1 has one cooling channel, both openings of which open to the same end surface. One cooling element may also have several cooling channels, such as two, three, or four cooling channels, and the opening of the cooling channel may also be open at the opposite end surface of the cooling element. Thus, in its simplest, the cooling channel can be a straight hole leading from the first end surface of the cooling element to the second end surface of the cooling element. Thus, the first flow tube is connected to the first opening of the cooling channel at the first end surface and the second flow tube is connected to the second opening of the cooling channel at the second end surface of the cooling channel.

Cooling liquid is guided through the inlet connection 114 to the bypass manifold 110 and continues from the bypass manifold to the respective cooling element through the first opening 106a along the first flow conduit 112a. . Inside the cooling element, heat is transferred from the cooling element to the cooling liquid via conduction. The cooling liquid exits the cooling element through the second opening 106b to the second flow tube 112b and subsequently to the bypass manifold. Any suitable cooling liquid such as tap water or a water and glycol mixture can be used as the cooling liquid in the system. In the present invention the flow tube and the cooling element are located around the coil so that the flow path of the cooling liquid does not form a closed ring around any individual conductor wire of the coil 100. Thus, even if an electrically conductive liquid such as tap water is used as the cooling liquid, no large voltage is induced in the cooling liquid circulating through the cooling system.

2a shows, by way of example, an advantageous embodiment of the cooling system according to the invention as shown above, in the longitudinal axis direction of the coil 100. In this advantageous embodiment of the present invention, the cooling element 102 is located inside the coil such that the second side surface 126 of the cooling element lies on the inner surface 120 of the coil. The interior of the coil in this presentation means a space formed in the center of the coil defined by the wire or foil layer of the coil. There are three cooling elements in this embodiment, which are placed on the inner surface of the coil at regular intervals. The first ends of the flow tubes 112a and 112b are connected to the bypass manifold 110 and the second ends are connected to the opening of the cooling channel at the first end surface of the cooling element. Thus, the cooling liquid enters the cooling element inside the coil through the opening at the first end of the coil and exits from the inside through the same opening. The cooling liquid is not guided to circulate around any individual conductor wire of the coil.

2b shows, as an example, a second advantageous embodiment of the cooling system according to the present invention, shown above in the longitudinal axis direction of the coil. In this embodiment the cooling element 102 is connected with the manufacture of the coil 100 located inside the coil between the superimposed coil wire or foil layers. Also in this embodiment the flow tube exiting the bypass manifold is connected to the cooling element so that the flow path of the cooling liquid does not circulate around any individual conductor wire of the coil (the flow tube and bypass manifold are shown in the figure). Not).

The cooling system shown in FIGS. 1A, 1B, 1C, 2A, and 2B has three or four cooling elements. However, the number of cooling elements is not limited to this number, but there may be other numbers among them as well. What is essential in the present invention is that there are many cooling elements where a sufficient cooling effect is obtained using the system. Thus, the appropriate number of cooling elements depends on the cooling requirements of the coil, which in turn depends on the number of wire turns of the coil and the amount of current through the coil. Thus, the system can include three, four, five, six, seven, or eight cooling elements. Testing has shown that in order to achieve sufficiently effective, uniform and distributed cooling, at least three cooling elements must be arranged in connection with the coil.

3A shows, by way of example, an advantageous embodiment of the individual cooling elements of the cooling system. In this embodiment the first face surface 124 of the cooling element is curved and the second face surface 126 is flat. The first surface has a radius of curvature R1. This advantageous embodiment of the cooling element is particularly well suited for use in a cooling system, in which case the cooling element is located inside the coil such that the first side surface 124 of the cooling element lies on the inner surface 120 of the coil. If the radius of curvature of the first face surface is chosen to be essentially the same as the radius of curvature r1 of the inner surface of the coil, heat is efficiently transferred from the coil to the cooling element.

3b shows as an example a second advantageous embodiment of the individual cooling elements 102 of the cooling system. In this embodiment both the first face surface 124 and the second face surface 126 of the cooling element are curved. The first surface has a radius of curvature R1 and the second surface has a radius of curvature R2. The radii of curvature R1 and R2 may be equally large or of different sizes. This advantageous embodiment of the cooling element is particularly well suited for use in the cooling element, in which case the cooling element is located outside the coil, so that the second side surface of the cooling element lies on the outer surface of the coil. If the radius of curvature R2 of the second face surface is chosen to be essentially the same as the radius of curvature r2 of the outer surface of the coil, heat is efficiently transferred from the coil to the cooling element. The cooling element shown in FIG. 3B is further suitable for positioning inside the coil between overlapping coil wire or foil layers.

4A-4C show particular embodiments of the cooling element shown in FIGS. 3A and 3B located in connection with different coils 100. In this figure, the coil is shown as shown at the end, in the longitudinal axis direction of the coil. In Fig. 4a there is a coil 100 having a circular cross section, the radius of the inner surface of which is r1. Three cooling elements 102 with the first surface 124 bent were placed in contact with the inner surface of the coil. The radius of curvature R1 of the face surface is essentially the same as the radius of curvature r1 of the inner surface.

In FIG. 4B there is a coil 100 having an elliptical cross section. This coil has a wall section s and its radius of curvature is r1. The cooling element 102 is located in contact with the wall section of the coil, and the radius of curvature R1 of the surface of the first face of the cooling element is essentially the same as the radius of curvature r1 of the wall section s1.

In Fig. 4C there is a coil 100 having a circular cross section, the radius of curvature of its outer surface 122 is r2. Four cooling elements 102 are located in contact with the outer surface 122 of the coil, and the radius of curvature R2 of the surface of the second side of the cooling element is essentially the same as the radius of curvature r2 of the outer surface of the coil.

4D shows the coil, where four cooling elements 102 have been installed inside the coil 100 between layers of superimposed wire or foil of the coil in connection with the manufacture of the coil. Both surface surfaces of the cooling element are curved.

5 shows an individual cooling element of a cooling system according to an embodiment of the present invention as shown obliquely above. The cooling channel 104 passes through the cooling element 102 starting at the first end surface 118 and ending at the second end surface 119. The first end surface 118 of the cooling element has a first opening 106a of the cooling channel through which cooling liquid flows into the cooling channel. The second end surface 106b of the cooling element has a second opening 106b through which cooling liquid exits the cooling channel.

Some advantageous embodiments of the method according to the invention, cooling systems, and coils have been described above. The present invention is not limited to the above-described solution, but the concept of the present invention can be applied in various ways within the scope of the claims.

Claims (21)

As a coil cooling method,
At least three cooling elements 102 are arranged in connection with the coil, and cooling liquid is guided to flow along the flow paths 110, 112a, 112b, 104 through the cooling elements, the flow paths being inside the cooling element. At least one cooling channel (104) formed, said cooling channel having a first opening (106a) for inflow of cooling liquid and a second opening (106b) for outflow of cooling liquid. In
The cooling element is arranged in connection with the coil so that the flow path of the cooling liquid does not form a uniform loop around the coil or around the individual conductor wire of the coil, Coil cooling method. The method of claim 1, wherein at least some of the cooling elements (102) are located outside the coil in contact with the outer surface (122) of the coil. Method according to claim 1 or 2, characterized in that at least some of the cooling elements (102) are located inside the coil in contact with the inner surface (120) of the coil. The coil 100 according to claim 1, wherein at least some of the cooling elements 102 are between the superposed conductor wire or the foil layer of the coil. It is located inside, the coil cooling method. 4. The method of claim 1, wherein the cooling element is located around the coil, so that the distance between adjacent cooling elements is essentially the same. 5. The coil cooling method according to any one of claims 1 to 5, wherein an electrically conductive liquid such as tap water is used as the cooling liquid. 7. The method of claim 1, wherein the method is used to cool one or more coils of a choke or transformer. A cooling system with liquid circulation for cooling the coil 100,
At least three cooling elements 102 to be arranged in connection with the coil and flow paths 110, 112a, 112b, 104 for cooling liquid for circulating cooling liquid through the cooling elements, the flow paths being At least one cooling channel 104 formed inside the cooling element, the cooling channel having a first opening 106a for the inlet of cooling liquid and a second opening 106b for the outflow of cooling liquid, In a cooling system,
The cooling element can be positioned to connect with a coil to be cooled, such that the flow path of the cooling liquid does not form a uniform ring around the coil or around individual conductor wires of the coil. 9. The cooling device of claim 8, wherein the first opening (106a) of the cooling channel (104) is at the first end surface (118) of the cooling element (102), and the second opening (106b) of the cooling channel. Is at the second end surface (119) of the cooling element. 10. The cooling channel (104) of claim 9, wherein the cooling channel (104) is a straight hole from the first end surface 118 of the cooling element 102 to the second end surface 119 of the cooling element. Characterized in that, a cooling system. Cooling system according to claim 8, characterized in that the cooling element (102) comprises at least two cooling channels (104). 12. Cooling system according to claim 11, characterized in that the cooling channels (104) of the cooling elements (102) are essentially parallel. 9. Cooling system according to claim 8, characterized in that the first opening (106a) and the second opening (106b) of the cooling channel (104) are on the same end surface. 14. The flow path according to any one of claims 8 to 13, wherein the flow path for the cooling liquid comprises a first flow conduit (112a) for guiding the cooling liquid into the cooling channel (104), and the cooling liquid out of the cooling channel. And a second manifold for guiding, and a bypass manifold, the flow duct being connected. The cooling element of claim 8, wherein the cooling element has at least one bent first surface surface 124, the first surface surface being the interior of the coil 100. Cooling system, characterized in that it can be placed on the surface. 16. The cooling element according to any one of claims 8 to 15, wherein the cooling element has at least one bent second surface surface 126, said second surface surface being able to lie on the outer surface of the coil 100. Characterized in that the cooling system. As a liquid cooled coil 100,
At least three cooling elements (102) with liquid circulation and flow paths (110, 112a, 112b, 104) for cooling liquid for circulating cooling liquid through the cooling elements, the flow paths being cooling elements At least one cooling channel 104 formed therein, the cooling channel having a first opening 106a for the inflow of cooling liquid and a second opening 106b for the outflow of the cooling liquid. In the coil,
Wherein the flow path of the cooling liquid does not form a uniform ring around the coil or around individual conductor wires of the coil. 18. The liquid cooling coil as claimed in claim 17, wherein the coil has an inner surface (120) and at least a portion of the cooling element (102) is located inside the coil in contact with the inner surface of the coil. 19. Liquid cooling according to claim 17 or 18, characterized in that the coil has an outer surface 122 and at least a portion of the cooling element 102 is located outside the coil in contact with the outer surface of the coil. coil. 20. The liquid cooling coil of claim 17, wherein at least a portion of the cooling element is located inside the coil between overlapping conductor wires or foil layers of the coil. 21. The liquid cooling coil as claimed in any one of claims 17 to 20, wherein the liquid cooling coil is a choke or a coil of a transformer.

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