WO2021022507A1

WO2021022507A1 - Cooling device for a transformer

Info

Publication number: WO2021022507A1
Application number: PCT/CN2019/099578
Authority: WO
Inventors: Ye XU; Qingjun SUN
Original assignee: Abb Schweiz Ag
Priority date: 2019-08-07
Filing date: 2019-08-07
Publication date: 2021-02-11
Also published as: EP4010911A4; EP4010911A1; CN114190107B; CN114190107A

Abstract

A cooling device (10) for a transformer (100) includes a row of three coil devices (2,4,6). The cooling device (10) comprises a first air fan (16) and a first ventilation unit (18). The first air fan (16) is arranged at a first side of a first coil device (4) of the three coil devices (2,4,6). The first ventilation unit (18) includes a first wing branch (13) coupling to the first air fan (16) and adapted to communicate air from the first air fan (16). The first wing branch (13) is adapted to extend into the bottom or the top of a first gap between the first coil device (4) and a second coil device (2), and comprises a first set of openings (15,17) adapted to communicate the air in the vertical direction. By utilizing embodiments of the disclosure, a better cooling effect can be achieved in a dry-type transformer (100).

Description

COOLING DEVICE FOR A TRANSFORMER

TECHNICAL FIELD

Example embodiments of the present disclosure generally relate to a cooling device and more particularly, to a cooling device for a transformer.

BACKGROUND

Transformers are widely deployed in various applications to provide various functions, such as voltage conversion. For example, a transformer may be provided in a substation of a power transmission system or a wind mill.

During conversion, some of the input power may not be transformed into desired electircal power. For example, a part of energy may be transformed into heat, causing an increasing temperature of the transformer. The increased temperature may lead to several disadvantages. For example, the transformer may age more rapidly, reducing its service life.

Various approaches have been proposed to reduce temperature of the transformers. For example, air circulation is provided in a dry-type transformer, and cooling oil is provided in an oil-filled transformer. CN104992815A describes such a dry-type transformer. However, the cooling effect can be further improved.

SUMMARY

Example embodiments of the present disclosure propose a solution of cooling a dry-type transformer.

In a first aspect, it is provided a cooling device for a transformer including a row of three coil devices. The cooling device comprises a first air fan and a first ventilation unit. The first air fan is arranged at a first side of a first coil device of the three coil devices. The first ventilation unit includes a first wing branch coupling to the first air fan and adapted to communicate air from the first air fan. The first wing branch is adapted to extend into bottom or top of a first gap between the first coil device and a second coil device. The first wing branch comprises a first set of openings adapted to communicate the air in the vertical direction.

In a second aspect, it is provided a transformer. The transformer comprises a first coil device, a second coil device, a third coil device arranged in a row with the first and second coil devices, and a cooling device of the first aspect.

In a third aspect, it is provided a method for manufacturing a cooling device. The method comprises providing a first air fan arranged at a first side of a first coil device, and providing a first ventilation unit including a first wing branch and coupled to the first air fan. The first ventilation unit is adapted to communicate air from the first air fan. The first wing branch is adapted to extend into bottom or top of a first gap between the first coil device and a second coil device. The first wing branch comprises a first set of openings adapted to communicate the air in the vertical direction.

According to the embodiments of the present disclosure, the converter according to embodiments of the present disclosure may achieve a desirable efficiency based on the proposed topology.

BRIEF DESCRIPTION OF THE DRAWINGS

Through the following detailed descriptions with reference to the accompanying drawings, the above and other objectives, features and advantages of the example embodiments disclosed herein will become more comprehensible. In the drawings, several example embodiments disclosed herein will be illustrated in an example and in a non-limiting manner, wherein:

Fig. 1 illustrates an internal structure of a dry-type transformer in accordance with some example embodiments of the present disclosure;

Fig. 2 illustrates a first part of a cooling device for a transformer in accordance with some example embodiments of the present disclosure;

Fig. 3 illustrates a ventilation unit of the cooling device of Fig. 2 in accordance with some example embodiments of the present disclosure;

Fig. 4 illustrates a wing branch of the ventilation unit of Fig. 3 in accordance with some example embodiments of the present disclosure; and

Fig. 5 illustrates an example of a method for manufacturing a cooling device in accordance with some example embodiments of the present disclosure.

Throughout the drawings, the same or corresponding reference symbols refer to the same or corresponding parts.

DETAILED DESCRIPTION

The subject matter described herein will now be discussed with reference to several example embodiments. These embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the subject matter described herein, rather than suggesting any limitations on the scope of the subject matter.

The term “comprises” or “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “or” is to be read as “and/or” unless the context clearly indicates otherwise. The term “based on” is to be read as “based at least in part on. ” The term “being operable to” is to mean a function, an action, a motion or a state can be achieved by an operation induced by a user or an external mechanism. The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ”

Unless specified or limited otherwise, the terms “mounted, ” “connected, ” “supported, ” and “coupled” and variations thereof are used broadly and encompass direct and indirect mountings, connections, supports, and couplings. Furthermore, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. In the description below, like reference numerals and labels are used to describe the same, similar or corresponding parts in the Figures. Other definitions, explicit and implicit, may be included below.

As mentioned above, cooling effect of the conventional cooling device is not ideal, and can be further improved. In an example, fans are placed at the front and rear ends of each coil in a cooling device. Generally, there are six fans located at the base of the coils. For the high-voltage coil, it is a complete hollow circle. The wing can be diffused into both sides to achieve better heat dissipation performance. For the low-voltage coil, however, it has multiple vents of the same size due to cooling ducts, and each vent is isolated from the other. Therefore, the coil is poorly ventilated away from the draught fan, resulting in a high temperature at the left and right ends of the low-voltage coil.

Fig. 1 illustrates an internal structure of a dry-type transformer 100 in accordance with some example embodiments of the present disclosure. The transformer 100 includes a row of three coil devices. The transformer 100 includes six fans located at the front and rear ends of the bases of the coil devices, as conventional transformers. The transformer 100 further includes a first cooling device 10 and a second cooling device (not shown) at the front and rear ends of the base or bottom of a first coil device 4, respectively.

In an example, the first coil device 4 is located between a second coil device 2 and a third coil device 6. The first cooling device 10 has a configuration substantially the same as the second cooling device. Thus, only the first cooling device 10 will be described below for brevity.

Although the first and second cooling devices are illustrated at the front and rear ends of the base or bottom of the first coil device, this is only for illustration without suggesting any limitations as to the scope of the subject matter described here. In an example, the first and second cooling devices may be provided at the front and rear ends of the top of the first coil device.

In another example, the first cooling device may be provided at the top of the first coil device 4, and the second cooling device may be provided at the bottom of the first coil device 4. In a further example, the first and second cooling devices may be provided at the front and rear ends of the middle of the first coil device 4. In this case, the ventilation unit may extend to the top or bottom of the first coil device 4 to communicate air, or communicate air through slots at the middle of the first coil device 4.

Although the first and second cooling devices are illustrated to be separate cooling devices, this is only for illustration without suggesting any limitations as to the scope of the subject matter described here. In an example, the first and second cooling devices may be provided as a single cooling device.

As shown in Fig. 1, there is a first gap between the first coil device 4 and the second coil device 2, and there is a second gap between the first coil device 4 and the third coil device 6. The inventor finds that heat tends to accumulate at the inner side of the coil devices, even with six air fans provided in the conventional approaches.

In other words, the heat tends to accumulate at the first and second gaps and the sides of the coil devices adjacent to the first and second gaps. In the conventional approaches, circulated air is difficult to reach these areas, or at least difficult to remove the accumulated heat in time.

Fig. 2 illustrates a first part of the cooling device 10 for a transformer in accordance with some example embodiments of the present disclosure. The first part of the cooling device 10 may be located at a front end of the first coil device 4. The cooling device 10 may further include a second part (not shown) of the cooling device 10 located at a rear end of the first coil device 4.

In an example, the first part of the cooling device 10 may include a first support base 12, a first air fan 16, a first motor 14 for driving the first air fan 16, and a first ventilation unit 18. The first support base 12 supports the first air fan 16 and the first motor 14. The first air fan 16 is arranged at a first side of the first coil device 4. The first side may be the front side in an example.

The ventilation unit 18 may include a first wing branch and a second wing branch. The first wing branch is coupled to the first air fan 16, and adapted to communicate air from the first air fan 16. The first wing branch may be a hollow structure in an example. The first wing branch may include a plurality of air channels arranged in parallel in another example.

The first wing branch may employ other structures in other examples, as long as it can communicate air from the first air fan. The first wing branch is adapted to extend into bottom or top of a first gap between the first coil device 4 and the second coil device 2. As shown in Fig. 1, there is a first gap between the first coil device 4 and the second coil device 2. The first wing branch comprises a first set of openings adapted to communicate the air in the vertical direction, as will be described below.

The first ventilation unit 18 may include a second wing branch spaced apart from the first wing branch. Although Fig. 2 illustrates a specific configuration of the first and second wing branches, this is only for illustration without suggesting any limitations as to the scope of the subject matter described here. In an example, the first ventilation unit 18 may has a “T” or a star shape. The air fan may provide air flow from a first end, and the air flow may flow out from the other two ends.

The second wing branch is adapted to extend into bottom or top of a second gap between the first coil device 4 and the third coil device 6, and comprises a second set of openings adapted to communicate the air in the vertical direction. In this example, the second wing branch may have a structure similar to or the same as the first wing branch. In this event, details of the second wing branch will not be described for brevity.

The second part (not shown) may include a second air fan arranged at a second side of the first coil device 4 and a second ventilation unit. The second side is opposite to the first side of the first coil device 4. The second ventilation unit includes a third wing branch coupling to the second air fan, and adapted to communicate air from the second air fan.

The third wing branch is adapted to extend into bottom or top of the first gap between the first coil device and the second coil device, and comprises a third set of openings adapted to communicate the air in the vertical direction.

The second ventilation unit includes a fourth wing branch spaced apart from the third wing branch. The fourth wing branch is adapted to extend into bottom or top of the second gap between the first coil device 4 and the third coil device 6, and comprises a fourth set of openings adapted to communicate the air in a vertical direction. Basically, the second part may have a structure similar to or the same as the first part in the example. In this event, the second part will not be illustrated and described for brevity.

Fig. 3 illustrates a ventilation unit 18 of the cooling device of Fig. 2 in accordance with some example embodiments of the present disclosure. The ventilation unit 18 may include the first wing branch 13 and the second wing branch spaced apart from the first wing branch 13.

In an example, the cooling device 10 may include a first three-way valve 13 coupled between the first air fan 16 and the first ventilation unit 18, and a second three-way valve coupled between the second air fan and the second ventilation unit. Although the three-way valve is illustrated, this is only for illustration without suggesting any limitations as to the scope of the subject matter described here. In an example, the three-way valve may be omitted, and the ventilation unit may be directly coupled with the air fan 16.

As shown in Fig. 3, the first wing branch 13 may include a first subset of openings 15 adapted to communicate the air into channels inside one of the first, second and third coil devices, and a second subset of openings 17 adapted to communicate the air into channels inside another one of the first, second and third coil devices. In an example, the first subset of openings 15 may communicate the air into channels inside the first coil device 4, and the second subset of openings 17 may communicate the air into channels inside the second coil device 2.

The first subset of openings 15 includes a first opening arranged to face a channel between a low voltage coil and an insulation barrier of one of the first, second and third coil devices, a second opening arranged to face a channel between the insulation barrier and a high voltage coil of the one of the first, second and third coil devices. The first or second subset of openings further includes a third opening arranged to face the low voltage coil of the one of the first, second and third coil devices.

In an example, the first subset 15 may include a first opening arranged to face a channel between a low voltage coil and an insulation barrier of the first coil device 4, a second opening arranged to face a channel between the insulation barrier and a high voltage coil of the one of the first coil device 4, and a third opening arranged to face the low voltage coil of the first coil device 4.

In the example, the second subset 17 may include a first opening arranged to face a channel between a low voltage coil and an insulation barrier of the second coil device 2, a second opening arranged to face a channel between the insulation barrier and a high voltage coil of the one of the second coil device 2, and a third opening arranged to face the low voltage coil of the second coil device 2.

Although three openings are illustrated for each subset in Fig. 3, this is only for illustration without suggesting any limitations as to the scope of the subject matter described here. In an example, the subset may include one, two or more than three openings. In addition, the opening may have various different shapes in this example.

By provide air circulation through the above channels and coils, the accumulated heat can be more rapidly removed, and the temperature at these local areas can be significantly reduced. As compared to providing air circulation between the coil devices or around the coil devices, the embodiment may provide significantly improved cooling effect due to the air flow through the channels between coils of a coil device. As such, the transformer may have a better performance and extend its service life.

Fig. 4 illustrates the first wing branch 13 of the ventilation unit of Fig. 3 in accordance with some example embodiments of the present disclosure. In order to demonstrate, the internal structure is illustrated with dotted lines, the air flow inside the first wing branch 13 is illustrated with the dotted arrow.

The first wing branch 13 includes a channel portion 31 coupled to one of the first and second air fans and an outlet portion coupled to the channel portion and between two of the three coil devices. In an example, the channel portion 31 is coupled to the first air fan, and the outlet portion is coupled to the channel portion 31 and between the first and second coil devices. As described above, the channel portion 31 is a hollow structure. In another example, the channel portion 31 may include a plurality of channels arranged in parallel.

In Fig. 4, first and second chambers are formed in the outlet portion by a partition member 34. In this case, the first chamber may be the left chamber 32, and the second chamber may be the second chamber 33. The left chamber 32 is illustrated to have a step structure 36 with dotted lines.

Although the step structure of the right chamber 33 is not illustrated, it is to be understood that the right chamber 33 has a step structure similar to that in the left chamber 32. In addition, only the air flows 22 are illustrated with dotted arrows to demonstrate that the air flows though the opening of the right chamber 33, it is to be understood that there are also air flows exiting from the openings at the left chamber 32.

The at least one of the first, second, third and fourth sets of openings is arranged on the top of the outlet portion, and the step structure 36 is arranged on the bottom of the outlet portion. In an example, the first and second sets of the openings are arranged on the top of the outlet portion, and the step structure 36 is arranged on the bottom of the outlet portion.

As show in Fig. 4, the air flow 21 from the air fan 16 flows inside the channel portion 31. The air flow 21 is then split into two streams when it passes by the partition member 34. The partition member 34 is arranged in the middle of the outlet portion to provide a first chamber 32 corresponding to one of subsets of openings of one of the first, second, third and fourth sets of openings and a second chamber 33 corresponding to another of subsets of openings of the one of the first, second, third and fourth sets of openings.

Although the partition member 34 is illustrated in Fig. 4, this is this is only for illustration without suggesting any limitations as to the scope of the subject matter described here. In an example, there may be no partition member 34 in the outlet portion. In another example, the partition member may have a shape of a triangle with a corner facing toward the air flow, such that the air flow is forced along the two sides of the triangle into the two chambers of the outlet potion. In this case, with a reduce volume as compared to the situation of the flat partition member 34, the air flow may flow faster to provide a better cooling effect.

In Fig. 4, the step structure 36 has two steps with a reduced thickness in a direction away from the channel portion 31. With the reduced thickness, the air flow may have a faster flow speed exiting the openings, when it flows in the direction away from the channel portion 31. As such, the transformer may have a better performance and extend its service life.

In an example, the outlet portion may include a first arc side adapted to match a lateral side of the first coil device and a second art side adapted to match a later side of the second or third coil device. In Fig. 4, the outlet portion may include a first arc side adapted to match a lateral side of the first coil device 4 and a second art side 35 adapted to match a later side of the second coil device 2.

At 202, it is provided a first air fan arranged at a first side of a first coil device.

At 204, it is provided a first ventilation unit including a first wing branch and coupled to the first air fan, the first ventilation unit being adapted to communicate air from the first air fan. The first wing branch is adapted to extend into bottom or top of a first gap between the first coil device and a second coil device, and comprises a first set of openings adapted to communicate the air in the vertical direction.

Although the method 200 is illustrated in Fig. 5, this is only for illustration without suggesting any limitations as to the scope of the subject matter described here. For example, it is to be understood that all the features for the Figs. 1-4 can be applied to the method 200.

Hereinafter, some example implementations of the subject matter described herein will be listed.

Item 1: There is provided a cooling device for a transformer including a row of three coil devices. The cooling device comprises a first air fan and a first ventilation unit. The first air fan arranged at a first side of a first coil device of the three coil devices. The first ventilation unit includes a first wing branch coupling to the first air fan and adapted to communicate air from the first air fan. The first wing branch is adapted to extend into bottom or top of a first gap between the first coil device and a second coil device, and comprises a first set of openings adapted to communicate the air in the vertical direction.

Item 2: The cooling device of Item 1, the first ventilation unit includes a second wing branch spaced apart from the first wing branch. The second wing branch is adapted to extend into bottom or top of a second gap between the first coil device and a third coil device, and comprises a second set of openings adapted to communicate the air in the vertical direction.

Item 3: The cooling device of

Item

1 or 2, further comprising a second air fan arranged at a second side of the first coil device, the second side being opposite to the first side of the first coil device, a second ventilation unit including a third wing branch coupling to the second air fan, and adapted to communicate air from the second air fan. The third wing branch is adapted to extend into bottom or top of the first gap between the first coil device and the second coil device, and comprises a third set of openings adapted to communicate the air in the vertical direction.

Item 4: The cooling device of any of Items 1-3, the second ventilation unit includes a fourth wing branch spaced apart from the third wing branch. The fourth wing branch is adapted to extend into bottom or top of the second gap between the first coil device and the third coil device, and comprises a fourth set of openings adapted to communicate the air in a vertical direction.

Item 5: The cooling device of any of Items 1-4, further comprising: a first three-way valve, coupled between the first air fan and the first ventilation unit; and a second three-way valve, coupled between the second air fan and the second ventilation unit.

Item 6: The cooling device of any of Items 1-5, wherein at least one of the first, second, third and fourth sets of openings includes a first subset of openings adapted to communicate the air into channels inside one of the first, second and third coil devices and a second subset of openings adapted to communicate the air into channels inside another one of the first, second and third coil devices.

Item 7: The cooling device of any of Items 1-6, wherein the first or second subset of openings includes a first opening arranged to face a channel between a low voltage coil and an insulation barrier of one of the first, second and third coil devices, a second opening arranged to face a channel between the insulation barrier and a high voltage coil of the one of the first, second and third coil devices.

Item 8: The cooling device of any of Items 1-7, wherein the first or second subset of openings further includes a third opening arranged to face the low voltage coil of the one of the first, second and third coil devices.

Item 9: The cooling device of any of Items 1-8, at least one of the first, second, third and fourth wing branches includes a step structure at a bottom side of the wing branch and opposite to the at least one of the first, second, third and fourth sets of openings.

Item 10: The cooling device of any of Items 1-9, wherein the at least one of the first, second, third and fourth wing branches includes a channel portion coupled to one of the first and second air fans and an outlet portion coupled to the channel portion and between two of the three coil devices. The at least one of the first, second, third and fourth sets of openings is arranged on the top of the outlet portion, and the step structure is arranged on the bottom of the outlet portion.

Item 11: The cooling device of any of Items 1-10, the outlet portion has a reduced thickness in a direction away from the channel portion.

Item 12: The cooling device of any of Items 1-11, wherein the outlet portion includes an internal partition member arranged in the middle of the outlet portion to provide a first chamber corresponding to one of subsets of openings of one of the first, second, third and fourth sets of openings and a second chamber corresponding to another of subsets of openings of the one of the first, second, third and fourth sets of openings.

Item 13: The cooling device of any of Items 1-12, wherein the outlet portion includes a first arc side adapted to match a lateral side of the first coil device and a second art side adapted to match a later side of the second or third coil device.

Item 14: It is provided a transformer comprising a first coil device, a second coil device, a third coil device arranged in a row with the first and second coil devices and a cooling device of any of Items 1-13.

Item 15: It is provided a method for manufacturing a cooling device. The method comprises providing a first air fan arranged at a first side of a first coil device, and providing a first ventilation unit including a first wing branch and coupled to the first air fan, the first ventilation unit being adapted to communicate air from the first air fan. The first wing branch is adapted to extend into bottom or top of a first gap between the first coil device and a second coil device, and comprises a first set of openings adapted to communicate the air in the vertical direction.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. On the other hand, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A cooling device (10) for a transformer (100) including a row of three coil devices, comprising:

a first air fan (16) arranged at a first side of a first coil device (4) of the three coil devices; and

a first ventilation unit (18) including a first wing branch coupling to the first air fan (16) , and adapted to communicate air from the first air fan;

wherein the first wing branch is adapted to extend into bottom or top of a first gap between the first coil device and a second coil device (2) , and comprises a first set of openings adapted to communicate the air in the vertical direction.
The cooling device of claim 1, wherein the first ventilation unit (18) includes a second wing branch spaced apart from the first wing branch;

the second wing branch is adapted to extend into bottom or top of a second gap between the first coil device and a third coil device (6) , and comprises a second set of openings adapted to communicate the air in the vertical direction.
The cooling device of claim 2, further comprising:

a second air fan arranged at a second side of the first coil device (4) , the second side being opposite to the first side of the first coil device; and

a second ventilation unit including a third wing branch coupling to the second air fan, and adapted to communicate air from the second air fan;

wherein the third wing branch is adapted to extend into bottom or top of the first gap between the first coil device and the second coil device, and comprises a third set of openings adapted to communicate the air in the vertical direction.
The cooling device of claim 3, wherein the second ventilation unit includes a fourth wing branch spaced apart from the third wing branch;

the fourth wing branch is adapted to extend into bottom or top of the second gap between the first coil device and the third coil device, and comprises a fourth set of openings adapted to communicate the air in the vertical direction.
The cooling device of claim 4, further comprising:

a first three-way valve, coupled between the first air fan and the first ventilation unit; and

a second three-way valve, coupled between the second air fan and the second ventilation unit.
The cooling device of claim 5, wherein at least one of the first, second, third and fourth sets of openings includes a first subset of openings adapted to communicate the air into channels inside one of the first, second and third coil devices and a second subset of openings adapted to communicate the air into channels inside another one of the first, second and third coil devices.
The cooling device of claim 6, wherein the first or second subset of openings includes a first opening arranged to face a channel between a low voltage coil and an insulation barrier of one of the first, second and third coil devices, a second opening arranged to face a channel between the insulation barrier and a high voltage coil of the one of the first, second and third coil devices.
The cooling device of claim 7, wherein the first or second subset of openings further includes a third opening arranged to face the low voltage coil of the one of the first, second and third coil devices.
The cooling device of claim 8, wherein at least one of the first, second, third and fourth wing branches includes a step structure at a bottom side of the wing branch and opposite to the at least one of the first, second, third and fourth sets of openings.
The cooling device of claim 9, wherein the at least one of the first, second, third and fourth wing branches includes a channel portion coupled to one of the first and second air fans and an outlet portion coupled to the channel portion and between two of the three coil devices; and

the at least one of the first, second, third and fourth sets of openings is arranged on the top of the outlet portion, and the step structure is arranged on the bottom of the outlet portion.
The cooling device of claim 10, wherein the outlet portion has a reduced thickness in a direction away from the channel portion.
The cooling device of claim 11, wherein the outlet portion includes an internal partition member (34) arranged in the middle of the outlet portion to provide a first chamber (32) corresponding to one of subsets of openings of one of the first, second, third and fourth sets of openings and a second chamber (33) corresponding to another of subsets of openings of the one of the first, second, third and fourth sets of openings.
The cooling device of claim 12, wherein the outlet portion includes a first arc side adapted to match a lateral side of the first coil device and a second art side adapted to match a later side of the second or third coil device.
A transformer (100) , comprising:

a first coil device (4) ;

a second coil device (2) ;

a third coil device (6) , arranged in a row with the first and second coil devices; and

a cooling device of any of claims 1-13.
A method for manufacturing a cooling device, comprising:

providing (202) a first air fan arranged at a first side of a first coil device; and

providing (204) a first ventilation unit including a first wing branch and coupled to the first air fan, the first ventilation unit being adapted to communicate air from the first air fan;

wherein the first wing branch is adapted to extend into bottom or top of a first gap between the first coil device and a second coil device, and comprises a first set of openings adapted to communicate the air in the vertical direction.