JPS636354A - Method of controlling cryogenic refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of controlling a cryogenic refrigeration system, and particularly to a method of controlling a cryogenic refrigeration system suitable for a system with large load fluctuations.

[Conventional technology]

Cryogenic refrigeration equipment, such as helium refrigeration equipment, has a liquefaction temperature as low as 1,269°C, so it is operated at a very wide range of temperatures from room temperature to liquefaction temperature. therefore,
The response time of the device to accommodate varying load numbers is very slow.

In order to cope with varying loads, conventional equipment has, for example, installed a heating means (e.g., a heater) inside the cryogenic liquefied gas container. As described in Japanese Patent Publication No. 108557/1983, the capacity of the compressor was controlled depending on the liquid level in the ultra-low 71 il liquefied gas container or the temperature at an appropriate point on the gas line.

However, no consideration was given to an appropriate operating method that takes into account load fluctuations and slow response times.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not have an appropriate operation control unit and IK that takes into account the response characteristics of the cryogenic refrigeration equipment, and when adjusting the load with a heater, there is a problem that unnecessary cooling is generated and efficiency is poor. , when controlling the capacity of the compressor,
The response time corresponding to the load is slow and difficult to control.
However, there is a problem in that the 1tfi of the compressor does not necessarily correspond to the load, making it difficult to control.

Further, the flow rate of the compressor does not necessarily correspond to the load depending on the case where cryogenic liquefied gas is recovered, and there are problems in directly controlling the flow rate based on the liquid level of ultra-low IPA liquefied gas.

An object of the present invention is to provide a control method for a cryogenic refrigeration system that can provide a method for controlling the response characteristics of a cryogenic refrigeration system with good consistency.

[Means for solving problems]

The above purpose is to adiabatically expand a part of the compressed high pressure gas,
In a method for controlling a cryogenic refrigeration apparatus, the remaining high pressure gas is cooled by the low pressure low temperature gas obtained from the first adiabatic expansion, and the cooled high pressure gas is expanded and liquefied by a Joule Thomson valve. controlling the flow rate of the high-pressure gas introduced into the expander that performs adiabatic expansion based on the load input value of the heating means, which controls the liquid volume in the cryogenic liquefied gas container that stores the liquefied gas; achieved.

[For production]

The liquid level in the cryogenic liquefied gas container rises and falls in response to changes in the load on the object to be cooled. In response to this, the load input value on the heater is directly adjusted by increasing or decreasing it, and the flow rate of high-pressure gas introduced into the expander, which is the source of cold in the cryogenic refrigeration equipment, is controlled by the load input value on the heater. This allows for smooth l
It is possible to maintain this in an appropriate operating state.

〔Example〕

An embodiment of the present invention will be explained below with reference to FIG. 1st
In the figure, 1 is a medium pressure tank, 2 is a compressor, 3 is a low pressure line pressure control valve, 3 is a high pressure line pressure control valve, 10 is a cold box, 11 a to 11 e are heat exchangers,
13a and 13b are expanders, 14 is a Joule-Thomson valve (hereinafter referred to as "JT valve"), (9
) is the cryogenic liquefied gas container, 21 is the object to be cooled, (9) is the heater, 31 is the liquid level gauge, dung is the heater control pipe, ( is the load input signal, the shoulder is the expander flow controller, A is the second The expander inlet pressure signal, violet is the expander artificial valve control signal, and g is the pressure gauge.

Next, the operation of the cryogenic refrigeration system of the present invention configured as shown in FIG.
After being cooled in the heat exchanger 11a, the high-pressure gas in the - part passes through the expander artificial valve conduit, undergoes adiabatic expansion in the first expansion 9.13a, lowers its temperature, and then enters the third heat exchanger. The liquid enters the vessel 11c, is further adiabatically expanded to a low pressure in the second expander 13b, and joins the low pressure line. - On the other hand, the remaining high pressure gas is
After being cooled in the fifth heat exchangers 11b to 11e, the mixture is expanded to a low pressure in the JT cell 14, and the - part is liquefied.

The liquefied cryogenic liquefied gas is introduced into an ultra-low a liquefied gas container, cools the object to be cooled and gasifies it, returns to the cold box 10, recovers its temperature in heat exchangers 11e to 11a, and then is compressed. Return to the suction side of machine 2. high pressure line.

The pressure of the low pressure line is controlled via the medium pressure tank 1 by the low pressure line pressure control valve 3. It is controlled by a high pressure line pressure regulating valve 4.

The liquid level of the whitening liquid in the cryogenic liquefied gas container rises and falls due to changes in the load on the object to be cooled (B), which is detected by the liquid level meter 31. In response to the sensed liquid level, the heater controller determines a load input value for the heater and sends a load input signal to the expander flow controller A.

Expansion 8! The flow control device calculates and outputs an expander artificial valve control signal I that controls the expander artificial valve according to the second expander inlet pressure signal and the afterload input signal.

As described above, according to this embodiment, direct adjustment corresponding to load fluctuations is performed by the heating means, and the flow rate of the expander, which is the source of cold generation, is controlled by the load input value in the heating means, so that the flow rate of the expander, which is the source of cold generation, is smoothly This has the effect of enabling appropriate operation control.

〔Effect of the invention〕

According to the present invention, it is possible to improve the responsiveness of the cryogenic refrigeration system in response to load fluctuations, so there is an effect that appropriate operation control can be performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a cryogenic refrigeration apparatus for explaining a method of controlling the cryogenic refrigeration apparatus according to an embodiment of the present invention. Minoru... Expander artificial valve, 13a, 13b...
... Expander, (9) ... Heater, 31 ...
··Liquid level indicator,!・・・・・・Heater control table 34-Ichisei Tamaisobetsu TFL Misaki

Claims (1)

[Claims] 1. A part of the compressed high-pressure gas is adiabatically expanded, the remaining high-pressure gas is cooled by the low-pressure low-temperature gas obtained by the adiabatic expansion, and the cooled high-pressure gas is expanded with a Joule-Thomson valve and liquefied. In the method for controlling a cryogenic refrigeration device, the expander that performs adiabatic expansion is controlled by a load input value of a heating means that adjusts the liquid amount in a cryogenic liquefied gas container that stores liquefied gas that has been liquefied by the Joule-Thomson valve. A method for controlling a cryogenic refrigeration system, characterized by controlling the flow rate of high-pressure gas introduced.