WO2018235940A1 - electromagnet - Google Patents

Abstract

The present invention provides an electromagnet which is capable of improving coil cooling efficiency. This electromagnet is provided with: a coil stack 20 obtained by stacking, in the vertical direction with spacers 22 therebetween, a plurality of coils 21 in which a plurality of conductor wires are integrated by being wound into a donut shape; a coil case 30 provided with a donut-shaped coil accommodation part for accommodating the coil stack; and a refrigerant liquid circulating and cooling mechanism which introduces a refrigerant liquid from a refrigerant liquid inlet 31e provided in the coil case, discharges the refrigerant liquid from a refrigerant liquid outlet 31f provided in the coil case 30, and, after cooling the refrigerant liquid, introduces the refrigerant liquid from the refrigerant liquid inlet 31e once again. The electromagnet is further provided with: first flow regulation plates 41 which inhibit the refrigerant liquid introduced from the refrigerant liquid inlet 31e from flowing along the outer circumferential surface of the coil stack 20; a second flow regulation plate 42 for inhibiting the refrigerant liquid from flowing along the upper surface of the coil stack 20; and a third flow regulation plate 43 for inhibiting the refrigerant liquid from rising up from a central portion of the coil stack 20.

Description

electromagnet

The present invention relates to an electromagnet, and more particularly to a cooling structure thereof.

Devices using electromagnets, regardless of their applications, have a structure in which current flows through the wires that make up the coil, the calorific value increases in proportion to the volume and increases with the cube of the dimensional ratio, while the surface area is 2 As the surface only serves as a heat dissipation surface, the cooling efficiency deteriorates. Therefore, conventionally, in order to increase the heat radiation area other than the surface, the lead wire (coil) is divided and a structure (patent document 1) to flow the refrigerant around it, or a combination of hollow lead wire and solid lead wire capable of flowing the refrigerant A structure (Patent Document 2) has been proposed.

Here, the heat transfer coefficient, which indicates the ease of transfer of heat from the heating element to the refrigerant, changes significantly depending on the type of refrigerant and the flow velocity. When a gas is selected as the refrigerant, it is about 10 to 250 kcal / (m ² · h · ° C.) in the flowing air. Also, it is about 50 to 1500 kcal / (m ² · h · ° C.) for flowing oil, and about 250 to 5000 kcal / (m ² · h · ° C.) for flowing water. That is, the use of a liquid rather than a gas as the refrigerant provides better cooling efficiency. From this, it is general to use a liquid refrigerant (refrigerant liquid) as a refrigerant for cooling the coil of the electromagnet, and in particular, insulating oil is widely used from the viewpoint of securing the insulation of the coil.

However, when refrigerant liquid is used as the refrigerant in the structure of Patent Document 1, in the structure of Patent Document 1, although the coil is divided and the passage of the refrigerant liquid is provided on the outer periphery of the coil, the circulation means is forced circulation However, even with natural circulation, in such a structure, a place where the refrigerant liquid easily flows and a place where it does not flow easily occur, which causes a variation in cooling, resulting in a problem that the cooling efficiency is lowered. Further, in the case of the structure of Patent Document 2, only the refrigerant in the hollow coil lead is forcedly circulated, so the hollow coil lead is cooled well, but the coil accommodation space outside the hollow coil lead is forcedly circulated. Also in this case, there is a problem that the cooling efficiency is lowered due to the variation of the cooling.

JP-A-52-57654 Japanese Patent Laid-Open No. 6-286970

The problem to be solved by the present invention is to provide an electromagnet capable of improving the cooling efficiency of the coil.

In order to solve this problem, in the conventional electromagnet provided with a coil stack in which a plurality of coils are stacked in the vertical direction, the inventors investigated in detail the cooling state of the coil stack by the refrigerant liquid. It was found that the flow rate of the refrigerant liquid flowing between the easily stagnant coils was smaller than expected, and as a result, the variation in cooling occurred and the cooling efficiency was lowered. Therefore, the present inventors have conceived of the present invention, aiming at a structure in which the refrigerant liquid can easily pass between the coils.

That is, according to one aspect of the present invention, the following electromagnet is provided.
"A coil laminated body formed by laminating a plurality of coils obtained by winding a plurality of lead wires in a donut shape integrally in the vertical direction via a spacer;
A coil case having a donut-shaped coil accommodating portion for accommodating the coil laminate;
The refrigerant liquid is introduced from the refrigerant liquid inlet provided in the coil case, the refrigerant liquid is discharged from the refrigerant liquid outlet provided in the coil case, and after cooling the refrigerant liquid, the refrigerant liquid is circulated again from the refrigerant liquid inlet. An electromagnet having a cooling mechanism,
A first straightening vane that suppresses the flow of the refrigerant liquid introduced from the refrigerant liquid inlet along the outer peripheral surface of the coil laminate;
A second straightening vane that suppresses the flow of the refrigerant liquid along the top surface of the coil laminate;
An electromagnet comprising: a third straightening vane for suppressing the coolant liquid from rising from a central portion of the coil laminate. "

According to the present invention, by providing the first to third flow control plates, the refrigerant liquid can easily pass between the coils where heat is most easily accumulated, and the cooling efficiency is improved.
Further, by improving the cooling efficiency, it is possible to suppress the decrease in current value under a constant applied voltage, and as a result, the magnetic flux density of the electromagnet can be maintained high. That is, since the amount of heat generation per unit volume of the electromagnet (coil) can be increased by improving the cooling efficiency, it is possible to achieve high magnetic flux density and miniaturization.
Furthermore, by improving the cooling efficiency, it is possible to eliminate the heat spot, to suppress the deterioration of the refrigerant liquid such as the insulating oil, and to suppress the generation of sludge and the reduction of the insulation resistance due to the deterioration of the refrigerant liquid.

FIG. 1A is a perspective view, FIG. 2B is an AA arrow view, and FIG. 2C is a BB arrow view. It is a figure which shows the coil laminated body with which the electromagnet of FIG. 1 is equipped, (a) is a perspective view, (b) is the figure seen from the refrigerant | coolant liquid inlet side. It is a perspective view which shows the case main body of the coil case with which the electromagnet of FIG. 1 is provided. It is a perspective view which shows the state which accommodated the coil laminated body of FIG. 2 in the case main body of FIG. It is an image figure which shows the flow of the refrigerant | coolant liquid when not providing the baffle plate. It is an image figure showing the flow of the refrigerant fluid at the time of providing the 1st straightening vane and the 4th straightening vane. It is an image figure which shows the flow of the refrigerant liquid at the time of providing a 2nd baffle plate further in FIG. It is an image figure which shows the flow of the refrigerant | coolant liquid at the time of providing a 3rd baffle plate further in FIG. It is a perspective view which shows the principal part of the electromagnet which is other embodiment of this invention. It is a perspective view which shows the principal part of the electromagnet which is other embodiment of this invention. It is a perspective view which shows the principal part of the electromagnet which is other embodiment of this invention. It is a schematic sectional drawing which shows the structure of an electromagnetic separator provided with the electromagnet which is one Embodiment of this invention.

FIG. 1 shows the main part of an electromagnet 10 according to an embodiment of the present invention, in which (b) is an AA arrow view and (c) is a BB arrow view. In FIG. 2, the coil laminated body 20 with which the electromagnet 10 is equipped is shown, (a) is a perspective view, (b) is the figure seen from the refrigerant liquid inlet side. FIG. 3 shows the case main body 31 of the coil case 30 provided in the electromagnet 10, and FIG. 4 shows a state in which the coil laminate 20 is accommodated in the case main body 31. As shown in FIG.

The electromagnet 10 shown in FIG. 1 includes a coil laminate 20 and a coil case 30 that accommodates the coil laminate 20.

As shown in FIG. 2, the coil laminate 20 includes a plurality of coils 21 formed by winding a plurality of conducting wires such as copper wires or aluminum wires in a donut shape integrally in the vertical direction via the spacer 22 (in the present embodiment Three sheets are stacked and sandwiched between the upper and lower pressure plates 23a and 23b, and the upper and lower pressure plates 23a and 23b are fastened by bolts 24 to be integrated. In addition, although each coil is electrically connected in series in this embodiment, you may connect in parallel.

The coil case 30 accommodating the coil laminate 20 includes a case body 31 and an upper lid 32. As shown in FIG. 3, the case main body 31 has an outer cylindrical portion 31a, an inner cylindrical portion 31b and a bottom portion 31c, and the coil laminate 20 is formed by the outer cylindrical portion 31a, the inner cylindrical portion 31b and the bottom portion 31c. The donut-shaped coil accommodating part 31d to accommodate is formed. After the coil stack 20 is housed in the coil housing portion 31d (see FIG. 4), the upper lid 32 is covered, whereby the coil stack 20 is housed in the coil case 30 (see FIG. 1). Although not shown, the coil laminate 20 is positioned and fixed to the inner peripheral surface of the outer cylindrical portion 31 a of the case main body 31 by fixing means such as bolts.

A refrigerant liquid inlet 31 e and a refrigerant liquid outlet 31 f are provided in the case main body 31 of the coil case 30. A refrigerant liquid circulation and cooling mechanism 50 (see FIG. 12) described later is connected to the refrigerant liquid inlet 31e and the refrigerant liquid outlet 31f. That is, the refrigerant liquid circulation and cooling mechanism 50 introduces the refrigerant liquid into the coil case 30 from the refrigerant liquid inlet 31e, discharges the refrigerant liquid from the refrigerant liquid outlet 31f, and after cooling the refrigerant liquid, the refrigerant liquid inlet 31f again. Introduce from. Thereby, the coil laminated body 20 (each coil 21) accommodated in the coil case 30 is cooled by the refrigerant liquid. The refrigerant liquid circulates in the coil case 30 so as to be filled to the extent that the coil stack 20 is immersed. In addition, as the refrigerant liquid, insulating oil such as mineral oil or silicone oil is suitable.

Here, to add the description of the spacers 22 installed between the coils 21 of the coil laminate 20, in the present embodiment, the spacers 22 are predetermined between the coils 21 as shown in FIG. 1 (b). The plurality of spacers (five in the present embodiment) are arranged at intervals of one another, and the plurality of spacers 22 are arranged in the flow direction of the refrigerant liquid from the refrigerant liquid inlet 31e toward the refrigerant liquid outlet 31f (coil lamination passing through the refrigerant liquid outlet 31f They are arranged parallel to each other along the diametrical center line L direction of the body 20 and in line symmetry with respect to the diametrical center line L of the coil stack 20. As a result, a plurality of refrigerant liquid flow paths are uniformly formed in parallel along the flow direction (diameter direction center line L direction) of the refrigerant liquid from the refrigerant liquid inlet 31e to the refrigerant liquid outlet 31f between the coils 21. It is formed.

In the above-described configuration, in the present embodiment, the first to fourth rectifying plates 41 to 44 are provided so that the refrigerant liquid can easily pass between the coils 21. Hereinafter, the function and effect of each of the rectifying plates will be described with reference to the drawings.

FIG. 5 is an image diagram showing the flow of the refrigerant liquid when the rectifying plate is not provided. This image is created based on the result of fluid analysis by computer. The solid line shows the flow on the outside of the coil laminate, the broken line shows the flow on the inside of the coil laminate (between coils), and the thickness of the wire is the flow rate Represents the abundance of Further, in this image view, the flange portion 31b-1 provided at the upper end of the inner cylindrical portion 31b of the case main body 31 shown in FIG. 3 is omitted to easily show the flow of the refrigerant liquid. The same is true for the following image diagrams (FIGS. 5 to 11):

In the case where the rectifying plate is not provided, as shown in FIG. 5, the refrigerant liquid passes through the flow channels 1 and 2 along the outer peripheral surface of the coil laminate having the largest passage area, so efficient cooling is achieved. It is not done. So, in this embodiment, in order to control passage of the refrigerant fluid to the channels 1 and 2 along the outer peripheral surface of the coil laminate, the first current plate 41 is provided in the middle of the channels 1 and 2 respectively. (See Figure 6). That is, the first straightening vane 41 suppresses the flow of the refrigerant liquid along the outer peripheral surface of the coil laminate. In the present embodiment, as shown in FIG. 1 (b), the first straightening vane 41 is disposed at the refrigerant liquid inlet 31e of the two spacers 22A and 22A positioned on the outermost side among the plurality of spacers 22. It is provided continuously at the near end. As a result, it is possible to almost completely suppress the flow of the refrigerant liquid along the outer peripheral surface of the coil stack. As described above, it is most preferable to provide the first straightening vane 41 so as to be continuous with the end of the spacer 22A, 22A on the side close to the refrigerant liquid inlet 31e. For example, the effect of suppressing the passage of the refrigerant liquid to the channels 1 and 2 can be obtained. However, from the point of suppressing the passage of the refrigerant liquid to the flow paths 1 and 2, the first current plate 41 is close to the two spacers 22A and 22A located on the outermost peripheral side among the plurality of spacers 22. It is preferable to provide at least two, and as in the present embodiment, it is most preferable to provide the spacer 22A, 22A at the end near the refrigerant liquid inlet 31e so as to be continuous.

Referring again to FIG. 6, in the present embodiment, in order to divide the flow of the refrigerant liquid introduced from the refrigerant liquid inlet in the vicinity of the refrigerant liquid inlet in the outer peripheral direction of the coil laminate, It is provided. By providing the fourth straightening vane 44, the flow of the refrigerant liquid can be equally divided in the outer peripheral direction of the coil stack. However, even if the fourth flow straightening plate 44 is not provided, the flow of the refrigerant liquid is diverted to some extent in the outer peripheral direction of the coil stack, so the fourth flow straightening plate 44 can be omitted.

Although the passage of the refrigerant liquid to the flow channels 1 and 2 is suppressed by providing the first rectifying plate 41 as described above, as shown in FIG. 6 as it is, on the upper surface of the coil laminate. Passage of the refrigerant liquid to the flow path 3 along the side increases. So, in this embodiment, in order to control passage of the refrigerant fluid to this channel 3, as shown in Drawing 7, the 2nd straightening vane 42 is provided. That is, the second straightening vane 42 suppresses the flow of the refrigerant liquid along the upper surface of the coil stack. In the present embodiment, the second straightening vanes 42 are provided such that both ends thereof are continuous with the two first straightening vanes 41, 41. This makes it possible to suppress the flow of the coolant liquid along the upper surface of the coil stack almost completely. As described above, it is most preferable to provide the second straightening vane 42 so that both ends thereof are continuous with the two first straightening vanes 41 and 41. However, if the second straightening vane 42 is provided in the middle of the flow path 3, the flow The effect of suppressing the passage of the refrigerant liquid to the passage 3 can be obtained. However, from the viewpoint of suppressing the passage of the refrigerant liquid to the flow path 3, it is preferable to provide the second straightening vane 42 so that both ends thereof are close to the two first straightening vanes 41, 41 As in the present embodiment, it is most preferable that the both ends be provided so as to be continuous with the two first current plates 41, 41.

By thus providing the first straightening vane 41 and the second straightening vane 42, the passage of the refrigerant liquid to the flow paths 1 to 3 is suppressed, but only by this, as shown in FIG. The passage of the refrigerant liquid to the flow path 4 in the direction of rising from the central portion of the coil stack is increased. So, in this embodiment, in order to control passage of the refrigerant fluid to this channel 4, the 3rd straightening vane 43 is provided (refer to Drawing 8). That is, the third straightening vane 43 suppresses the coolant liquid from rising from the central portion of the coil stack. In the present embodiment, the third straightening vane 43 has a cylindrical shape that continuously rises from the inner hole surface of the coil laminate. The third straightening vane 43 is not limited to a cylindrical shape, and may be, for example, an annular shape that blocks the flow path 4, but the third laminated plate may be accommodated in the coil case (coil accommodation portion) of the coil laminate. From the viewpoint of ease, it is preferable to have a cylindrical shape as in the present embodiment.

As described above, in the present embodiment, by providing the first straightening vanes 41 and 41, the second straightening vane 42 and the third straightening vane 43, the passage of the refrigerant liquid to the flow paths 1 to 4 is The refrigerant liquid is allowed to pass between the coils 21 (flow paths 5 to 8 shown in FIG. 8) in which the refrigerant liquid is most likely to retain heat. Thereby, since the cooling efficiency of the coil laminated body 20 (each coil 21) improves, the fall of an electric current value can be suppressed and, as a result, the magnetic flux density of the electromagnet 10 can be maintained high. Furthermore, by improving the cooling efficiency, it is possible to eliminate the heat spot, to suppress the deterioration of the refrigerant liquid such as the insulating oil, and to suppress the generation of sludge and the reduction of the insulation resistance due to the deterioration of the refrigerant liquid. In fact, according to the test results of the inventors of the present invention, according to the electromagnet 10 of the present embodiment, the reduction of the current value is about 20% to about 10% as compared with the conventional electromagnet (FIG. 5) having no rectifying plate. It reduced. In addition, the temperature of the refrigerant liquid (insulation oil) was able to be reduced to 50 degrees or less at which the maximum temperature is reduced from about 120 degrees to about 40 degrees and sludge is generated.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this. For example, as shown in FIG. 9, the second straightening vane 42-1 can be provided integrally with the third straightening vane 43. Further, as shown in FIG. 10, the rectifying plate 42-2 may be provided closer to the refrigerant liquid outlet than the inner hole of the coil laminate. The rectifying plate 42-2 not only suppresses the flow of the refrigerant liquid along the upper surface of the coil stack, but also suppresses the rising of the refrigerant liquid from the inner hole (central portion) of the coil stack. Also play. That is, the rectifying plate 42-2 functions as a "second rectifying plate" in the present invention and also functions as a "third rectifying plate". In other words, the rectifying plate 42-2 corresponds to both the "second rectifying plate" and the "third rectifying plate" in the present invention, and the "second rectifying plate" in the embodiment of FIG. And “the third straightening vane” is provided. Thus, the shape and position of the “second rectifying plate” are not limited as long as the refrigerant liquid can be prevented from flowing along the upper surface of the coil laminate, and the “third rectifying plate” is also limited. The shape and position of the coolant liquid are not limited as long as the coolant liquid can be prevented from rising from the central portion (inner hole) of the coil laminate. Similarly, the shape and position of the “first rectifying plate” are not limited as long as the refrigerant liquid can be inhibited from flowing along the outer peripheral surface of the coil laminate.

Further, as shown in FIG. 11, a plurality of refrigerant liquid inlets 31e can be provided. In this case, each refrigerant liquid inlet 31e is preferably provided so as to be axisymmetric with respect to the diametrical center line passing through the refrigerant liquid outlet 31f. When a plurality of refrigerant liquid inlets 31e are provided as shown in FIG. 11, the fourth rectifying plate 44 divides the refrigerant liquid flow into two parts (divided into two) in the outer peripheral direction of the coil laminate, It is preferable to provide on the diametrical centerline which passes through. A plurality of refrigerant liquid inlets 31f can also be provided.

Next, an electromagnetic separator will be described as an application example of the electromagnet 10 of the embodiment shown in FIG. The structure of the electromagnetic separator 60 provided with the electromagnet 10 of this embodiment is shown in FIG. 12 by a schematic cross section. Further, FIG. 12 also shows a refrigerant liquid circulation cooling mechanism 50 which is a component of the electromagnet 10. The refrigerant liquid circulation and cooling mechanism 50 is connected to a refrigerant liquid inlet 31 e and a refrigerant liquid outlet 31 f provided in the coil case 30 of the electromagnet 10. Then, the refrigerant liquid circulation and cooling mechanism 50 introduces the refrigerant liquid into the coil case 30 from the refrigerant liquid inlet 31e, discharges the refrigerant liquid from the refrigerant liquid outlet 31f, cools the refrigerant liquid, and then again from the refrigerant liquid inlet 31f. A pump 51 and a heat exchanger 52 are provided for introduction. By the refrigerant liquid circulation and cooling mechanism 50, the coil stack 20 (each coil 21) accommodated in the coil case 30 is cooled by the refrigerant liquid. In addition, the structure of the electromagnet 10 is simplified and shown in FIG. 12, For example, the above-mentioned each baffle plate and spacer are abbreviate | omitted.

In the electromagnetic separator 60 of FIG. 12, the cylinder 61 is disposed in the inner cylindrical portion 31 b of the coil case 30 of the electromagnet 10, and the screen 62 made of a plate-like magnetic material is a screen holding rod 63 in the cylinder 61. Are stacked in the vertical direction and arranged in multiple layers. The rims 64 are provided at predetermined intervals in the vertical direction on the outer circumference of the cylinder 61, and the electromagnet 10 surrounds the outer circumference of the cylinder 61 between the upper and lower rims 64 and keeps a small gap therebetween. It is attached via a spring 65. A vibrator 66 is attached to the lower portion of the tube 61.

In this electromagnetic separator 60, vibration is given to the tube 61 by starting the vibrator 66, and energization of the electromagnet 10 is started, so that each screen 62 in the tube 61 is a magnetic material and is in the magnetic field of the electromagnet 10. Magnetize because it is located. Therefore, if powder is introduced from the upper end opening of the cylinder 61, the powder is diffused by the action of vibration while falling through the respective screens 62 sequentially from the top while the magnetic foreign matter is magnetized during this time. The powder adsorbed and remaining by the respective screens 62 and from which the magnetic foreign matter has been removed is derived from the lower end opening of the cylinder 61. When the separation operation for a fixed amount or for a fixed time is completed, the supply of the powder is stopped, and when the energization to the electromagnet 10 is stopped, most of the magnetic foreign matter is dropped and discharged. Then, after deenergizing the vibrator 66, the upper end of the holding rod 63 holding the screen 62 is held and the upper end of the holding rod 63 is pulled out. Since all of the screens 62 are held by the holding bar 63, the entire screen 22 together with the holding bar 63 is simultaneously taken out from the inside of the tube 61. The removed screen 62 is cleaned to further remove magnetic foreign matter. The cleaned screen 62 is returned to the inside of the cylinder 61 again, the powder is supplied, and the removal operation of the magnetic foreign matter is started.

In addition, the electromagnet 10 of this embodiment is naturally applicable also to electromagnetic separators other than this electromagnetic separator 60, For example, it applies to the suspension electromagnet currently indicated by the said patent document 1, 2 other than an electromagnetic separator, for example You can also

DESCRIPTION OF SYMBOLS 10 electromagnet 20 coil laminated body 21 coil 22 spacer 23a, 23b pressure plate 24 coil case 31 case main body 31a outer cylinder 31b inner cylinder 31b-1 flange 31c bottom 31d coil housing 31e refrigerant liquid inlet 31f refrigerant liquid outlet 32 upper lid 41 first straightening vane 42, 42-1 second straightening vane 42-2 second straightening vane (third straightening vane)
43 third rectifying plate 44 fourth rectifying plate 50 refrigerant liquid circulation cooling mechanism 51 pump 52 heat exchanger 60 electromagnetic separator 61 cylinder 62 screen 63 screen holding bar 64 flange 65 spring 66 vibrator

Claims (5)

A coil laminated body formed by laminating a plurality of coils obtained by winding a plurality of conductive wires in a donut shape and integrating the plurality of coils in the vertical direction via a spacer;
A coil case having a donut-shaped coil accommodating portion for accommodating the coil laminate;
The refrigerant liquid is introduced from the refrigerant liquid inlet provided in the coil case, the refrigerant liquid is discharged from the refrigerant liquid outlet provided in the coil case, and after cooling the refrigerant liquid, the refrigerant liquid is circulated again from the refrigerant liquid inlet. An electromagnet having a cooling mechanism,
A first straightening vane that suppresses the flow of the refrigerant liquid introduced from the refrigerant liquid inlet along the outer peripheral surface of the coil laminate;
A second straightening vane that suppresses the flow of the refrigerant liquid along the top surface of the coil laminate;
An electromagnet comprising: a third straightening vane for suppressing the coolant liquid from rising from a central portion of the coil laminate. The plurality of spacers are arranged at intervals, and the plurality of spacers are parallel to each other along the flow direction of the refrigerant liquid from the refrigerant liquid inlet to the refrigerant liquid outlet, and the diametrical center line of the coil laminate Arranged in line symmetry with respect to
At least two of the first straightening vanes are provided in the vicinity of two spacers positioned on the outermost side among the plurality of spacers,
The electromagnet according to claim 1, wherein the second straightening vane is provided such that both ends thereof are close to the two first straightening vanes. At least two of the first straightening vanes are provided so as to be continuous with the end on the side closer to the refrigerant liquid inlet in the two spacers positioned on the outermost peripheral side among the plurality of spacers.
The electromagnet according to claim 2, wherein the second straightening vane is provided such that both ends thereof are continuous with the two first straightening vanes. The electromagnet according to any one of claims 1 to 3, wherein the third current plate has a cylindrical shape which continuously rises from the inner hole surface of the coil laminate. The fourth flow straightening plate is provided in the vicinity of the refrigerant liquid inlet, for dividing or dividing the flow of the refrigerant liquid introduced from the refrigerant liquid inlet in the outer peripheral direction of the coil laminated body. The electromagnet as described in any one.

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