JPH07109326B2 - Compact He condensate liquefier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a compact He condensate liquefier refrigeration system.

(Prior Art) FIG. 3 is a flow chart of He condensation and liquefaction using a conventional Gifford McMahon (GM) cycle + JT circuit. A He gas source such as a He gas cylinder (not shown) is connected to the condensate liquefaction system 12, and the pressure is reduced to 1.0 kg / cm ² G or less by the pressure reducing valve 13 and the J-
Similar to the cooling part of the T circuit, thermal contact such as wrapping pipes around the heat load flanges 14 and 15 of the GM cycle refrigerator 2 of the GM cycle refrigerator 2 is measured and introduced into the liquid He container 6 to be condensed. It was liquefied at 10. However, the liquefaction capacity is about 30% lower than that of direct liquefaction. The reason for this is that in the direct liquefaction method, the liquefied He gas is continuously cooled from room temperature to near the condensation temperature. However, in the condensing liquefaction method, since the cooling is only performed by the first and second stage heat load flanges 14 and 15 and the condenser 10, the cooling is intermittent and at the same time, the first and second stage heat load flanges 14 and 1
The heat exchange is performed in the state where the temperature difference between the condenser 5 and the condenser 10 is large (in the range of several hundred degrees Celsius to several tens of degrees Celsius). This is because the thermal efficiency is reduced.

(Problems to be solved by the invention) The maximum liquefaction capacity of a small He liquefaction device is a method of directly introducing a gas-liquid mixed gas after a JT valve to a liquefied He storage container and separating the gas-liquid to store the liquid He. Obtained when (direct liquefaction method),
In the method of condensing and liquefying He gas at a low temperature to store liquid He (referred to as condensing liquefaction method), the liquefaction capacity is reduced by about 30% compared to the direct liquefaction method. Theoretically, the amount of freezing heat required to turn the He gas at room temperature into liquid He is almost the same. The present invention seeks to improve this capability.

(Solution by the Invention) A Joule Thomson (J-
T) In a He refrigerating apparatus in which a circuit and a He refrigerator 2 for precooling He gas passing through the circuit are combined, multi-stage heat exchangers 3, 4, 5 on the high pressure side of the Joule-Thomson circuit and heat exchange before condensation on the low pressure side Bowl 1
6 has a He gas supply circuit for condensing and liquefying, and He gas passing through the circuit is cooled by the He refrigerating machine 2 for precooling, and this is cooled by the JT circuit. The system He gas was passed through all the heat exchangers and the heat load flanges of the He refrigerator.

(Example) An example will be described with reference to FIG. Flow into condensing liquefaction system 12
In order to cool the He gas from room temperature to condensation and liquefaction as continuously as possible, after passing through the pressure reducing valve 13, the first stage heat exchanger 3, the first stage heat load flange 14, the second stage heat exchanger 4 of the JT circuit. , The second stage heat load flange 15, the third stage heat exchanger 5 to cool, and finally the pre-condensation heat exchanger 16 to further cool by the He gas on the low pressure side 11 of the JT circuit that has left the condenser 10 and then condensate. It is designed to be condensed and liquefied in the vessel 10.

FIG. 2 shows an example of a mounting structure for a one-stage to three-stage heat exchanger. The hot condensed gas is introduced into the copper tube 12a. The copper tube 12a is spirally wound and soldered on the tubular portion of the heat exchanger 3 (4,5).

With this configuration, the high-temperature condensed gas is transferred to the first-stage heat exchanger 3,
It is cooled by the first stage heat load flange 14, the second stage heat exchanger 4, the second stage heat load flange 15, the third stage heat exchanger 5, and the pre-condensation heat exchanger 16. That is, the first to third stage heat exchangers 3, 4, and the pre-condensation heat exchanger 16 are added. Therefore, the thermal efficiency of the work for cooling the condensed and liquefied He gas can be improved, and the temperature at the time of flowing into the LHe container 6 can be lowered, so that the liquefaction capacity can be further improved.

(Effect) Joule Thomson (J-
T) In a He refrigerating apparatus in which a circuit and a He refrigerator 2 for precooling He gas passing through the circuit are combined, multi-stage heat exchangers 3, 4, 5 on the high pressure side of the Joule-Thomson circuit and heat exchange before condensation on the low pressure side Bowl 1
6 has a He gas supply circuit for condensing and liquefying, and He gas passing through the circuit is cooled by the He refrigerating machine 2 for precooling, and this is cooled by the JT circuit. The system He gas was passed through all the heat exchangers and the heat load flanges of the He refrigerator.

In this way, in the cooling process of the high temperature condensed gas, the heat load flange of the He refrigerator for pre-cooling and the total heat exchanger of the JT circuit are used for continuous cooling, so the cooling efficiency is improved. ,
The inflow temperature to the LHe container can also be lowered, and it has become possible to improve the liquefaction capacity by 20% compared to the conventional level.

[Brief description of drawings]

FIG. 1 shows a compact He liquefaction refrigeration system according to the present invention. FIG. 2 shows an example of the mounting structure of the condensation system tube to the heat exchanger. FIG. 3 shows a conventional compact He liquefaction refrigeration system. In the figure; 1 ... compressor unit 2 ... Gifford McMahon cycle refrigerator 3 ... one-stage heat exchanger, 4 ... two-stage heat exchanger 5 ... three-stage heat exchanger, 6 ... liquid He container 7 …… Shield plate, 8 …… JT circuit high pressure side 9 …… JT valve, 10 …… Condenser 11 …… JT circuit low pressure side, 12 …… Condensation liquefaction system 13 …… Decompression valve 14… … 1st stage heat load flange 15 …… 2nd stage heat load flange 16 …… Heat exchanger before condensation, 17 …… Vacuum insulation container

Claims (1)

[Claims] 1. A Joule-Thomson (JT) circuit having a multistage condensing heat exchanger, and He for precooling He gas passing through the circuit.
In a He refrigeration system that combines a refrigerator (2), He for condensing and liquefying by a multistage heat exchanger (3,4,5) on the high-pressure side of the Joule-Thomson circuit and a pre-condensation heat exchanger (16) on the low-pressure side. A gas supply circuit is provided, He gas passing through the circuit is cooled by the He refrigerator (2) for pre-cooling, and this is cooled by the JT circuit. A compact He condensate liquefaction refrigeration system characterized by passing through a heat load flange of an exchanger and a He refrigerator.