JPS6231181A - Helium container for superconducting energy storage apparatus - Google Patents

Abstract

PURPOSE:To improve airtightness and relieve thermal stress by a method wherein an intermediate material such as kovar is inserted between a ceramics and a metal helium container wall and soldered to form a junction for a countermeasure against circulating current. CONSTITUTION:A ceramics such as porcelain 11 is employed as an insulator in a vertical cross section of a liquid helium container 1 to avoid a circulating current. Generally speaking, the linear thermal expansion coefficient of the helium container 1 is substantially different from the coefficient of the porcelain 11. Therefore, in order to relieve thermal stress at the low temperature, a material which has an intermediate linear thermal expansion coefficient, such as kovar 12, is inserted between the helium container 1 and the porcelain 11. The airtightness can be ensured by soldering the helium container 1 and the kovar 12 and soldering the kovar 12 and the porcelain 11.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a helium container for a superconducting energy storage device.

[Conventional technology]

FIG. 3 shows a partial diagram of the superconducting energy storage device. A superconductor 02 and an AJ alloy brick 03 are contained inside the liquid helium container 01, and are immersed in liquid helium. Each turn of the A1 alloy plink 03 is insulated by an insulating plate 04 between the conductor turns, and vertically connected by a tightening pole 05 between the conductor turns. The internal pressure applied to the inner wall plate of the liquid helium container 01 is balanced with the internal pressure applied to the outer wall plate of the liquid helium container 01 via the helium container reinforcing stay 06 and the A1 alloy brick 03. The electromagnetic force generated by the current passing through the superconductor 02 is transmitted via the A1 alloy brick 03 to the vertical column 07 forming a part of the helium container, and further transmitted to the rock via the heat insulating support member 08. In addition, the liquid helium container 01 is kept vacuum cooled, and a radiation shield 09 is provided outside the liquid helium container 01.
There is.

4 and 5 are horizontal cross-sectional views of the vertical struts of FIG. 3; FIG. FIG. 4 shows the normal part, and the vertical support 07 is composed of an FRP support 07g in contact with the A7 alloy brick 03 and an SUS support 07b connected to the container 01. However, if all the connections between the liquid helium container 01 and the vertical support 07 are in this structure, heat generation due to the circulating current is unavoidable, so the container wall needs to be electrically insulated at at least one place on the circumference. In this structure, as shown in Fig. 5, a plate 09 joined to the container wall is inserted between the FRP (fiber reinforced plastic) vertical support 07 b' between the container walls and the FR support support 07G that receives the coil. However, after this plate 09 is bonded to the support column 076' with adhesive, the stud bolt 010 is attached.
Stop with.

[Problem that the invention seeks to solve]

In the conventional technology, there is a possibility that helium gas leaks at the joints of the vertical columns, and vacuum cooling may not be achieved. Therefore, it is necessary to develop an adhesive method that does not cause leakage.

[Means to solve all problems]

Since it is difficult to eliminate leaks with adhesives, ceramics are used as the insulating material. However, since the linear expansion coefficients of ceramics and ordinary low-temperature materials (for example, austenitic stainless steel) are quite different, a material with an intermediate linear expansion coefficient (for example, Kovar) is inserted between the two. By brazing each of these spaces, airtightness is ensured.

[Effect]

The cystine-free helium container is insulated with an insulating material such as ceramics, completely preventing the generation of circulating current, and ensuring vacuum cooling with reliable airtightness.

〔Example〕

In FIG. 1, circulating current is prevented by using ceramics such as porcelain 11 as an insulating material on one vertical section of a liquid helium container 1. In addition, helium container 1 and porcelain 1
Since the coefficient of linear expansion is generally slightly different from that of 1, a material with an intermediate coefficient of linear expansion (for example, Kovar 12) is inserted between the helium container 1 and the porcelain 11 to relieve thermal stress at low temperatures. do.

Helium container 1 and Kovar 12. Kovar 12 and porcelain 1
1 and is joined by brazing to ensure airtightness.

Figure 2 shows AI as an insulating material! 203 material 11' for material 1'
Use wo.

〔Effect of the invention〕

As a joining method for the circulating current countermeasure section, the airtightness is improved by brazing ceramics.

Furthermore, between the ceramic and the metal helium container wall,
Thermal stress is alleviated by inserting an intermediate member such as Kovar.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention, FIG. 2 is a schematic diagram of another embodiment, FIG. 3 is a schematic diagram of a conventional device, and FIGS.
The figure is a horizontal sectional view of the vertical strut of FIG. 3. 1...Liquid helium container, 11...Ceramics,
12... Kobar sub-agent Patent attorney Shige Okamoto 2 people outside the kiln Figure 1 Figure 2

Claims (1)

[Claims] In a helium container that has an insulating material inserted into the metal container wall of the liquid helium container that surrounds the superconductor to prevent the generation of circulating current, ceramics are used as the insulating material, and a ceramic material is used at the joint between the insulating material and the container wall. A helium container for a superconducting energy storage device, characterized in that a material having a coefficient of linear expansion is inserted and each material is brazed to form an airtight structure.