JPS6050355A - 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 (a) Field of Industrial Application The present invention relates to a cryogenic refrigeration system that can be suitably used in cryopumps, helium liquefaction equipment, and the like.

(b) Prior Art Cryopumps, small helium liquefaction equipment, etc. use cryogenic compact refrigerators that utilize gas cycles such as the Kifford-McMahon cycle, the Solvay cycle, and the Stirling cycle.

By the way, a conventional cryopump, for example, as shown in FIG. 1, has a cold box a with heat insulation measures,
Cryopanels b and c are arranged in this cold box a and sequentially liquefy and adsorb the gas in the box a;
It is equipped with a Solvay cycle type cryogenic freezing device d for cooling the cryopanels b and c. The refrigeration device d includes an expander e that is connected to a generator m for energy absorption and adiabatically expands the introduced gas to lower its temperature, a regenerator f whose low-temperature end is connected to the expansion 411e, and a regenerator f that A supply air path communicating with the discharge port g1 of the compressor g or an exhaust path i communicating with the suction port g2 is connected to the high temperature end of the device f.
It is equipped with a timing valve j for selectively connecting the cryopanels b and c to a cold rad provided in the casing of the expander e. However, in the conventional system, the entire cold storage device e, which is a pre-cooling means, is housed in the cold box a, which is supposed to house the cold storage device h. In other words, in the conventional type, the expander and the entire precooling means are integrated in the cold head portion, so the cold head portion, H1, N, and the like increase the size of the cold box a. As a result, not only is the production cost of the cold box, which is a vacuum insulated container, high, but the main body of the cryopump, of which the cold head of the refrigeration equipment is one of the essential components, is unduly large. As a result, the degree of freedom in installation is reduced, and it becomes difficult to secure installation space, which poses a problem.

(c) Purpose This invention was created with a focus on such pleasure.
An object of the present invention is to provide a cryogenic refrigeration device that can reduce the size of a cold head portion disposed within a cold box.

(d) Structure In order to achieve the above object, the present invention provides an insulating tube communicating with the cold box outside the cold box in which the heat load such as the cryopanel, the cold heater, and the expander are housed. It is characterized in that a part or all of the precooling means is housed within the heat insulating tube.

(E) Example An example of the present invention will be described below with reference to FIGS. 2 and 3.

FIG. 2 is a schematic sectional view of the cryopump, and FIG. 3 is an explanatory diagram of its circuit. This cryopump is a cold box with airtightness and heat insulation.
The cold box 1 is equipped with a cryo panel 2.3 disposed inside the cold box 1, and an ultra-low single-island freezing device 4 for cooling these cryopanels 2 and 3. The cryonocular 2.3 is made by forming a thin metal plate with good heat conduction into a cylindrical shape with a bottom, and the second stage cryopanel 3 is arranged inside the first stage cryopanel 2. ing. Further, the cryogenic freezing device 4 is of a Claude cycle type,
A pair of expanders 5.6, an air supply path 8 that supplies high-pressure refrigerant gas A such as helium discharged from the compressor 7 to the high-pressure ports 5a and 6a of each of the expanders 5.6, and each expansion An exhaust path 9 that returns the low-temperature, low-pressure refrigerant gas B discharged from the low-pressure ports 5b and 6b of the machines 5 and 6 to the compressor 7, and the cold air of the gas B in this exhaust path 9 is used to generate the air supply. It is equipped with a cooling means lO for pre-cooling the waste A in the path 8, and each cryopanel 2. 3 to be cooled. The expanders 5 and 6 rotate the rotating body 5C16C connected to an energy absorption generator (not shown).
Expansion chambers 5d to 5g, 6d to 6g formed around the outer periphery of 6C
It is a rotary type that can increase or decrease its volume. The high-pressure boats 5a, 6a are communicated with expansion chambers 5d, 6d whose volumes are about to increase as the recirculation body 5C16C rotates, and the low-pressure boats 5b, 6b are connected to expansion chambers 5d, 6d whose volumes are about to increase as the recirculation body 5C16C rotates. Some expansion chambers 5f, 5g
, 6f, and 6g. Further, the precooling means 10 includes each trunk 8a of the air supply path 8 and the exhaust path 9,
A main heat exchanger 13 and a first auxiliary heat exchanger 14 are interposed between the main heat exchanger 13 and the first auxiliary heat exchanger 14, and a second auxiliary heat exchanger 15 is interposed between the branch parts 8b and 9b of the air supply path 8 and the exhaust path 9.
It consists of The main heat exchanger 13, which is a part of the cooling means io, is housed in a heat insulating tube 16 and is disposed outside the cold box l. The heat insulating tube 16 has an outer shell 17 surrounding both the paths 8.9, and a vacuum heat insulating layer 18 between the outer shell 17 and the both paths 8.9 to prevent heat from entering from the outside. is the provision. Furthermore, if necessary, super insulation (not shown) made of aluminum insulation or the like is provided on this vacuum insulation layer 18. Note that one end of the heat insulating tube 16 is connected to the cold box 1, and the non-heat exchanger accommodating portion 16a of the tube 16 is made to be flexibly deformable ζIf.

like this,? If it is of the i-a configuration, the J) 0 refrigeration device 4 will continue to perform the claw cycle and absorb the heat existing in its cold heads 11 and 12, so each of these cold heads The cryopanel 2.3 connected to 11.12 can be cooled and functions as a cryopump. Moreover, this one is a main heat exchanger 13 which is a part of the precooling means lO of the refrigeration device 4.
is housed in a heat insulating tube 16 and placed outside the cold box l. Therefore, it is only necessary to arrange a very small auxiliary heat exchanger 14.15 in the cold box 1, and the components integrated into the cold box 11.12 can be made smaller and lighter in weight. can be measured. In other words, if this is the case, the only component that will be integrated into the cold herad 11.12 will be the expander 5.6, and it will be best to store it in an extremely small cold box l. become capable. Therefore, it is not only possible to manufacture the cold box l easily and reduce costs, but also to make the main body of the cryopump, whose main part is the cold compartment F'11.12 of the refrigeration system 4, smaller. Moreover, it can be made lightweight. Therefore, the degree of freedom in installation is increased,
This has the effect of making it easier to secure installation space.

In the above embodiment, a case where a part of the precooling means is arranged outside the cold box has been described, but the present invention is of course not limited to such a case, and the entire precooling means is disposed outside the cold box. It may also be placed outside the cold box. That is, in this case, for example, the main heat exchanger 13 shown in FIG. 2 may be made slightly larger, and the auxiliary heat exchanger 1 may be
4.15 will be omitted.

Further, the gas cycle is not limited to the Claw 1 cycle, and may be, for example, a Sorbet cycle, a Gifford-McMahon cycle, a Stirling cycle, or the like. Fourth
The figure shows a case 1 in which the present invention is applied to a sorbet cycle type refrigeration device 4'. In this device 4', a precooling means 24 is constituted by a heat exchanger 21 and a pair of regenerators 22 and 23. The heat exchanger 21, which is a part of the precooling means 24, is housed in the heat insulating tube 16 and is disposed outside the cold box 1. In addition, in FIG. 4, 25 is a timing valve, and 26 is the expander 5.6.
This is a generator connected to. In yet another embodiment of the present invention, the timing valve 25 is disposed closer to the compressor 7 than the second heat exchanger, and the second heat exchanger functions as a regenerator. can also be considered.

Furthermore, the heat load is not limited to cryopanels, and can be modified in various ways without departing from the spirit of the present invention.

Effects Since the present invention has the above-described configuration, it is possible to provide a cryogenic refrigeration system that can reduce the size of the cold storage section disposed in the cold box.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing a conventional example. FIG. 2 is a schematic sectional view showing one embodiment of the present invention, and FIG. 3 is an explanatory diagram of the same circuit. FIG. 4 is a schematic sectional view showing another embodiment of the present invention. 1...Cold box 2.3...Heat load (cryo panel) 4.4゛...Φ
Refrigeration device 5.6・◆・Expanser 7Φ・・Compressor 8##O Air supply path 9 *e・Exhaust path 10.24 drops・・Precooling means 11.12**s Cold head 16・・Insulation tube Agent Patent Attorney Hiroshi Akazawa

Claims (1)

[Claims] An expander that expands and lowers the temperature of the high-pressure cold gas supplied from the compressor, and pre-cools the refrigerant scum introduced into the expander using the cold air of refrigerant gas derived from this expander. In the refrigeration system, the refrigeration system is equipped with a pre-cooling means such as a regenerator or a heat exchanger, and is configured such that the heat load can be cooled by a cold head provided near the IV6 expansion machine, wherein the heat load, the cold head, and the expansion machine A cryogenic freezing apparatus characterized in that an insulating tube communicating with the cold box is provided outside the cold box in which the precooling means is housed, and a part or all of the precooling means is accommodated within the insulating tube.