JPS593543Y2 - boiling cooled electromagnet - Google Patents

Description

[Detailed description of the invention] This invention relates to a field electromagnet used as a field on the moving body side of a synchronous linear motor, and is particularly concerned with a field electromagnet that is used as a field magnet on the moving body side of a synchronous linear motor. This invention relates to improvements in boiling-cooled electromagnets having a structure.

Patent application 1982-1099 previously proposed by the inventor of the present application, etc.
In the boiling cooling type electromagnet disclosed in No. 41, the annular coil housed in the annular cooling tank body is arranged in upper and lower positions such that the longitudinal axis of the cooling tank body and the longitudinal axis of the coil coincide. Since it has a symmetrical structure, the voids for collecting air bubbles generated in the cooling medium are mainly formed between the coil side and the opposing inner wall of the cooling tank, which reduces the amount of heat generated by the coil. The problem was discovered that the upper side of the coil is exposed to the gas region, resulting in areas with different cooling efficiencies.

This invention focuses on this point and is an improvement on it, in which the coil is surrounded by an annular boiling cooling tank body so that a cooling medium flow path is formed between the outer surface of the annular coil and the inner wall surface of the cooling tank body. In a boiling-cooled electromagnet in which an iron core is fitted together with the annular coil, the longitudinal axis of the annular coil is shifted downward with respect to the longitudinal axis of the annular cooling tank body, and the annular coil and the cooling tank body are housed vertically asymmetrically. Due to the tight structure,
This is a boiling cooling type electromagnet in which a gas region is created by air bubbles generated by vaporization of the cooling medium inside the cooling tank without touching the coil.

Preferred embodiments of this invention will be described below with reference to the drawings.

FIG. 1 shows this invention in longitudinal section, and FIG. 2 is a perspective sectional view taken along line AA' in FIG.

In FIGS. 1 and 2, the electromagnets are annular cooling tank bodies 1 and 1.
', an annular coil 2 housed in the cooling tank body 1, 1',
2', an iron core 3 having magnetic pole parts 5, 5' facing each other with a predetermined gap into which the upper tank part 4 of the cooling tank bodies 1, 1' is fitted;
Insulators 7, 7' and 8, 8' interposed between the inner peripheral surfaces of the coils 2, 2' and the hollow body wall of the annular cooling tank body 1, and the liquefied cooling medium in the cooling tank body 1. A conduit 9 for returning the cooling medium, and a conduit 10 for sending the vaporized cooling medium from the upper part of the cooling tank body 1 to a condenser (not shown).

As shown in FIG. 2, the coils 2, 2' and the cooling tank body 1
The thickness d of the insulator 7.7' interposed between the lower wall of the upper tank part 4 and the earthen wall of the lower tank part 12 of the cooling tank body 1 and the coil 2,
Since there is a relationship d<D with respect to the thickness D of the insulators 8 and 8' interposed between 14 by a length corresponding to D-d.

In this way, the coils 2, 2' are connected to the cooling tank body 1 by D-d.
As shown in FIG. 2, a sufficiently large gap can be formed on both sides of the upper part of the upper tank part 4 and the insulator 8.8' of the lower tank part 12, as shown in FIG. The void at the upper side becomes a gas flow path and collects the bubbles of the cooling medium, and since the coils 2 and 2' are located below this part, the coils 2 and 2' are not directly exposed to the gas region and are constantly liquefied. It is immersed in a coolant coolant to provide a uniform cooling effect.

Next, using the experimental apparatus shown in Figures 3 and 4, we will calculate the heat flux when the coil is directly exposed to a gas region where bubbles are concentrated when the cooling medium is vaporized due to the heat generated by the coil. That is, the relationship between the burnout heat flux value and the thickness dimension of the insulator interposed in the coil will be explained.

First, in the experimental apparatus shown in FIGS. 3 and 4, a cooling medium such as fluorine oil is placed in a tank 15, and a heating element 16 having a built-in electric heating coil is housed in the tank 15.
A baffle plate 18 is placed through the heat generating element 15, and a spacer 19 is interposed at a position of length l from one side end of the heat generating element 15 to partition the heat generating element 15, and a spacer 20 is placed on both sides of the heat generating element 16 at a distance ΔR.
A condenser 21 is further provided at the top of the tank 15.

In this experimental apparatus, l = 600 mm, and the insulator 1
By changing the thickness D of 7, △R=5mm, lQmm and 20
The burnout heat flux at mm was measured, and the results shown in the graph of FIG. 5 were obtained.

As is clear from the graph in FIG. 5, the thickness D of the insulator 17
As the heat flux increases, the cross-sectional area of the flow path through which the bubbles pass increases, so the bubbles quickly flow through the flow path and are discharged, so that the burnout heat flux increases linearly.

Assuming now that the design value of the burnout heat flux in the embodiment shown in FIGS. Assuming that R2 is 10 mm, and taking the insulator 8 interposed in the lower tank part 12 as an example, from the graph of FIG. 5, D=
lQmm is obtained, and the thickness of the insulator 8 can be determined to be 10 mm.

Further, the value of d at this time is determined in consideration of the insulation between the coil and the cooling tank body.

Note that this invention is not limited to a case in which the coil is offset within the cooling tank body through the interposition of an insulator, but is also applicable to a case in which the longitudinal axis of the coil is offset downward with respect to the longitudinal axis of the cooling tank body. It includes an appropriate structure for causing the problem to occur.

As explained above, the boiling-cooled electromagnet of this invention has a vertically asymmetric storage structure in which the longitudinal axis of the coil is shifted downward by a predetermined length with respect to the longitudinal axis of the annular cooling tank body. The air bubbles generated by the vaporization of the cooling medium due to the heat generated by the coil can make the gas area formed above the coil sufficiently large, and the upper part of the coil is exposed to the gas area, making the cooling efficiency different from other parts. Unbalanced cooling efficiency is avoided, and stable boiling cooling of the coil can be achieved at all times.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of this invention;
Figure 2 is a cross-sectional perspective view taken from line A-A' in Figure 1;
Figure 4 is an explanatory diagram of the experimental equipment for measuring burnout heat flux due to the presence of an insulator, and Figure 5 shows the relationship between the thickness of the insulator and the burnout heat flux obtained with the experimental equipment shown in Figures 3 and 4. FIG. 1.1'...Cooling tank body, 2,2'...
Coil, 3... Iron core, 4... Upper tank section,
5.5'...Magnetic pole part, 7.7', 8.8'...
... Insulator, 9, 10 ... Conduit, 12 ...
...Lower tank section, 15...Tank, 16...
... Heating element, 17 ... Insulator, 18 ...
...Baffle plate, 19°20...Spacer, 21.
·····Condenser.

Claims (1)

[Scope of Claim for Utility Model Registration] A boiler formed by surrounding an annular boiling cooling tank body and inserting an iron core so that a cooling medium flow path is formed between the outer surface of the annular coil and the inner wall surface of the cooling tank body. A boiling cooling type electromagnet characterized in that the longitudinal axis of the annular coil is shifted downward with respect to the longitudinal axis of the annular cooling tank body, and the annular coil is housed in the cooling tank body.