JP2887923B2 - Helium liquefaction refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helium gas liquefaction refrigerator. The apparatus of the present invention uses one compressor,
It supplies liquefied helium to each of two refrigeration loads, and can be applied to, for example, a super-electric magnetic levitation train (linear motor car).

[0002]

2. Description of the Related Art Helium gas compressed to high temperature and pressure
When supplying helium liquefied refrigeration equipment of two systems, helium gas is usually supplied to each system independently using two compressors. But 2
The weight of the two compressors is very large.
When mounted on a marker, it is fatally large.

For this reason, there is a demand for a system in which helium gas can be supplied by a single compressor to two systems of helium liquefaction refrigeration systems having substantially the same refrigeration load. In order to respond to such a request, an apparatus shown in FIGS. 4 and 5 has been proposed. In the linear motor car, the refrigeration loads of the two systems can be regarded as being the same.

[0004] In the apparatus shown in FIG. 4, pipes derived from the discharge section of one compressor 20 are branched into two systems, and needle valves 20 a and 20 b are respectively provided for the pipes of each system. ,
By adjusting the dollar valves 20a and 20b, the supply amount of helium gas to each system is controlled to be the same.

[0005] As shown in Japanese Patent Publication No. 2-47674, the apparatus shown in FIG. 5 branches helium gas discharged from the compressor 50 into three systems a, b, and c.
This is a device for returning from d to the compressor 50. Here, system a
From the heat exchangers 61,62,63,64
a, and then to the cryogenic environment section 54a,
Similarly, the system b includes heat exchangers 61, 62,
From 63,64, it goes to the Joule-Thomson valve 52b and further to the cryogenic environment section 54b, and thereafter returns to the system d.
Further, the system c reaches the expanders 71 and 72, and then the system d
Return to

In such a configuration, in the apparatus shown in FIG. 5, the temperature of the discharge side of the expander 71 and the downstream side of the confluence of the return system d is measured, and the controller 81 controls the expander 71 based on the result. The temperature of the discharge side of the expander 72 and the downstream side of the junction of the return system d are measured, and the controller 82 controls the rotational speed of the expander 72 based on the measurement result. Thus, the flow rate of the helium gas is controlled.

[0007]

The device shown in FIG. 4 has a problem that the efficiency is reduced because the needle valves 20a and 20b become resistance. Further, in the apparatus of FIG. 5, there is a problem in reliability of the flow rate adjusting mechanism. The present invention has been made in view of such circumstances, and a single compressor can be used for two helium liquefaction refrigeration systems having substantially the same refrigeration load without lowering the efficiency and with high reliability. An object is to provide a device that can supply helium gas.

[0008]

According to the present invention, the helium gas supplied to each of the two systems is precooled stepwise by heat exchange, and then the Joule-Thomson valve is used. Helium liquefaction refrigeration system, which liquefies by passing through and passes it to the refrigeration load corresponding to each system, has two compression units of the same performance as means for supplying helium gas at normal temperature and high pressure to the two systems. Liquefied refrigeration system that sets the same refrigeration capacity to each system by using two heat exchange means of the same performance as means for pre-cooling helium gas stepwise by heat exchange using a compressor equipped with It is.

In the above, the stepwise precooling is performed until the temperature of the helium gas becomes lower than the reversal temperature. Also,
The Joule-Thomson valve is a valve configured to produce the Joule-Thomson effect.

[0010]

[Function] Each of the two systems is supplied with helium gas at normal temperature and high pressure from the compression units having the same performance. The helium gas is cooled stepwise below the reversal temperature by heat exchange means of the same performance, then liquefied by passing through a Joule-Thompson valve, and supplied to refrigeration loads of the same size. You.

[0011] Thus, the refrigerating capacity of the two systems is balanced.

[0012]

Embodiments of the present invention will be described below. Figure 1 shows
FIG. 2 is a conceptual diagram showing an overall configuration of a helium liquefaction refrigeration apparatus according to a first embodiment, and FIG. 2 is a cross-sectional view schematically showing a configuration of a main part of a compressor 2 used in the apparatus.

This helium liquefaction refrigeration system is a device for a linear motor (superconducting magnetic levitation train), and has two superconducting coils 14a and 14b having substantially the same refrigeration load, and a valve or
This is a device that cools by one compressor 2 without performing complicated pressure control.

The compressor 2 has two systems of compression units 4a and 4b. The helium gas compressed and discharged in the compression section 4a is supplied to the heat exchanger 5, the precooling heat exchanger 9 of the Stirling cycle refrigerator 1a, the heat exchanger 6, and the precooling heat exchanger of the refrigerator 1a.
10,..., Sequentially cooled down to a temperature not higher than the reversal temperature by the heat exchanger 8, and then liquefied by passing through a Joule-Thomson valve (a valve having the Joule-Thomson effect) 12. Is stored in the tank 13a and the superconducting coil 14
a is cooled and then vaporized and returned to the suction side of the compressor 2.

Helium gas compressed and discharged in the compression section 4b is also liquefied in the same manner as described above,
b, and cools the superconducting coil 14b. Here, the superconducting coils 14a and 14b are disposed on both sides of the vehicle in the linear motor car, and their refrigeration loads are substantially the same.

In the above, refrigerators having the same performance are used as the stirling cycle refrigerators 1a and 1b. Also, as described above, the two superconducting coils 14a,
The refrigeration load of 14b can be considered to be approximately the same. Therefore, the refrigerating capacity of the superconducting coils 14a, 14b can be balanced by configuring the performance of the compression units 4a, 4b to be the same.

Next, details of the compression units 4a and 4b will be described. As shown in FIG. 2, the compressor 2 has compression pistons 15a and 16a and compression pistons 15b and 15b via a single crankshaft 19 directly connected to the rotation shaft of one motor 3. 16b is configured to operate. Here, the compression part composed of the compression piston 15a and the cylinder 17a and the compression part composed of the compression piston 15b and the cylinder 17b have the same shape, and are composed of the compression piston 16a and the cylinder 18a. The compression section composed of the compression section and the compression piston 16b and the cylinder 18b also has the same shape. That is, the shapes of the compression parts on both sides shown in FIG. 2 are equal.

Here, a compression part 4a is constituted by the compression pistons 15a, 16a and their cylinders 17a, 18a, and the compression pistons 15b, 16b and their cylinders 17b, 18b
Constitutes a compression unit 4b.

In other words, each compression section 4a, 4b of the compressor 2
Have the same shape (volume for compressing the working gas) and have the same crankshaft 19 by the same motor 3.
Is driven through. Therefore, the performances of the compression units 4a and 4b can be considered to be the same. As described above, the present apparatus is an apparatus that can cool two superconducting coils 14a and 14b having substantially the same refrigeration load by using one compressor 2.

FIG. 3 is a conceptual diagram showing the overall configuration of a helium liquefaction refrigeration apparatus according to a second embodiment. The device shown in FIG. 3 is different from the device shown in FIG. 1 in that bypass lines 21 and 22 having pressure regulating valves 21 and 22 are provided in the respective systems a and b, and return to the compressor 2 is performed. The gas flow path is separated into two systems, thereby further stabilizing the performance and adjusting the pressure regulating valves 21 and 22 even when a difference in the refrigeration load occurs in the superconducting coils 14a and 14b. Thereby, refrigeration corresponding to each system can be generated without lowering the efficiency.

[0021]

As described above, according to the present invention, a helium gas is supplied to two systems by a compressor having two compression units of the same performance, and precooled by heat exchange means of the same performance. This is a helium liquefaction refrigeration system that liquefies by passing through a Le Thomson valve and supplies it to refrigeration loads corresponding to each system.

According to the present invention, there is no reduction in efficiency, and
Helium gas can be supplied to two helium liquefaction refrigeration units with high reliability for liquefaction. Also,
One compressor is enough and its weight is not excessive,
For example, it can be mounted on a linear motor car and used.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a helium liquefaction refrigeration apparatus according to a first embodiment.

FIG. 2 is a cross-sectional view schematically illustrating a configuration of a compressor used in the embodiment device.

FIG. 3 is an explanatory diagram showing a configuration of a helium liquefaction refrigeration apparatus according to a second embodiment.

FIG. 4 is an explanatory diagram showing a configuration of a conventional helium liquefaction refrigeration apparatus.

FIG. 5 is an explanatory diagram showing a configuration of an apparatus disclosed in Japanese Patent Publication No. 2-47674.

[Explanation of symbols]

 1a, 1b Stirling cycle refrigerator, 2 compressors, 4a, 4b compression section, 5,6,7,8 heat exchanger, 12 Joule-Thomson valve, 14a, 14b superconducting coil,

Claims (1)

(57) [Claims] 1. Helium gas at normal temperature and high pressure is supplied to two systems, and in each system, the helium gas is precooled step by step by heat exchange and then liquefied by passing through a Joule-Thomson valve. In a helium liquefaction refrigeration system that supplies helium gas at room temperature and high pressure to two refrigeration loads corresponding to the respective refrigeration loads, A helium liquefaction refrigeration system that sets the same refrigerating capacity to each system by using two heat exchange means of the same performance as a means for pre-cooling helium gas stepwise by heat exchange using a heat exchanger.