JP2012057871A - Pulse tube refrigerating machine, and superconductive magnet device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulse tube refrigerating machine that improves cooling efficiency, and also to provide a superconductive magnet device using the same.SOLUTION: An orifice open-and-close valve 14 (V4) which opens and closes in synchronization with a periodical opening-and-closing operation of a feed valve 2 and an exhaust valve 3 is disposed on orifice piping 9. In addition, a double inlet open-and-close valve 13 (V3) which opens and closes in synchronization with the periodical opening-and-closing operation of the feed valve 2 and the exhaust valve 3 is disposed on double inlet piping 6.

Description

  The present invention relates to an orifice / double inlet type pulse tube refrigerator and a superconducting magnet apparatus using the same.

  The pulse tube refrigerator is one of the regenerative refrigerators, and is a highly reliable refrigerator because it has no moving parts in the low temperature part compared to the Gifford McMahon (GM) refrigerator and the Stirling refrigerator. However, since there is no piston or displacer in the expansion space, various phase control mechanisms have been devised to establish a refrigeration cycle.

  One typical control mechanism is an orifice / double inlet type pulse tube refrigerator (for example, Patent Documents 1 to 4).

Special table 2008-527308 gazette JP 2008-224142 A JP 2009-63209 A JP 2000-310458 A

  In general, the orifice / double inlet system has only two on-off valves and can be equivalent to a GM refrigerator, but a part of the refrigerant gas flowing into the pulse tube from the double inlet piping side passes through the orifice piping and is buffered. There is a problem that it flows into the tank. This inflowing gas does not contribute to the generation of cold and leads to an increase in the flow rate and an increase in the pressure of the intermediate pressure buffer, which causes a decrease in cooling efficiency.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a pulse tube refrigerator having improved cooling efficiency and a superconducting magnet device using the same.

  A pulse tube refrigerator according to an aspect of the present invention includes a compressor that compresses refrigerant gas, an air supply valve that opens and closes in a flow path that supplies refrigerant gas compressed by the compressor, and a refrigerant after use An exhaust valve that opens and closes in a flow path for returning gas to the compressor; a regenerator that communicates with the air supply valve and the exhaust valve via an air supply / exhaust pipe; and a double inlet for the air supply valve and the exhaust valve The orifice pipe comprising: a pulse pipe communicating with a low temperature end of the regenerator through a cooling stage; and a buffer tank communicating with the high temperature end of the pulse pipe through an orifice pipe. In addition, an orifice opening / closing valve that opens and closes in synchronization with a periodic opening / closing operation of the air supply valve and the exhaust valve is provided.

  A pulse tube refrigerator according to another aspect of the present invention includes a compressor that compresses refrigerant gas, an air supply valve that opens and closes in a flow path that supplies refrigerant gas compressed by the compressor, An exhaust valve that opens and closes in a flow path that returns the refrigerant gas to the compressor, a regenerator that communicates with the air supply valve and the exhaust valve via an air supply / exhaust pipe, and a double air supply to the air supply valve and the exhaust valve. A pulse tube communicating with the low temperature end of the regenerator via a cooling stage, and a buffer tank communicating with the high temperature end of the pulse tube via an orifice piping. The inlet pipe is provided with a double inlet on / off valve that opens and closes in synchronization with the periodic opening and closing of the air supply valve and the exhaust valve.

  A pulse tube refrigerator according to another aspect of the present invention includes a compressor that compresses refrigerant gas, an air supply valve that opens and closes in a flow path that supplies refrigerant gas compressed by the compressor, An exhaust valve that opens and closes in a flow path that returns the refrigerant gas to the compressor, a regenerator that communicates with the air supply valve and the exhaust valve via an air supply / exhaust pipe, and a double air supply to the air supply valve and the exhaust valve. A pulse pipe communicating with the low temperature end of the regenerator via a cooling stage, and a buffer tank communicating with the high temperature end of the pulse pipe via an orifice pipe. An orifice opening / closing valve that opens and closes in synchronization with the periodic opening / closing operation of the supply valve and the exhaust valve is provided in the pipe, and the supply valve and the exhaust valve are periodically provided in the double inlet pipe. Wherein the double inlet closing valve for opening and closing operation in synchronization with the opening and closing operation is provided.

  According to the present invention, a pulse tube refrigerator with improved cooling efficiency and a superconducting magnet device using the same can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the orifice double inlet type pulse tube refrigerator which concerns on the 1st Embodiment of this invention. The timing chart which shows the refrigerating cycle in the pulse tube refrigerator of the embodiment. The 1st conceptual diagram for demonstrating the flow of an invalid compressed gas, and the flow of an ideal compressed gas. The 2nd conceptual diagram for demonstrating the flow of an invalid compressed gas, and the flow of an ideal compressed gas. The schematic block diagram of the pulse tube refrigerator which concerns on the 2nd Embodiment of this invention. The timing chart which shows the example of the refrigerating cycle when the time which the orifice on-off valve is open is lengthened when the temperature of the cooling stage is high in the same embodiment. The schematic block diagram of the superconducting magnet apparatus which concerns on the 3rd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
First, a first embodiment of the present invention will be described.

  FIG. 1 is a configuration diagram showing a schematic configuration of an orifice / double inlet type pulse tube refrigerator according to a first embodiment of the present invention.

  The pulse tube refrigerator according to the first embodiment is an orifice / double inlet type pulse tube refrigerator, and includes a compressor 1, an air supply valve 2 (V1), an exhaust valve 3 (V2), and an air supply / exhaust pipe 4. , Regenerator 5, double inlet pipe 6, cooling stage 7, pulse pipe 8, orifice pipe 9, buffer tank 10, double inlet flow rate adjuster 11, orifice flow rate adjuster 12, double inlet on / off valve 13 (V 3), orifice open / close A valve 14 (V4) is provided.

  The compressor 1 constitutes a high and low pressure source (pressure oscillation source) and compresses the refrigerant gas.

  The air supply valve 2 (V1) is an open / close valve that opens and closes in a flow path that supplies the refrigerant gas compressed by the compressor 1 to a cold head (not shown).

  The exhaust valve 3 (V2) is an open / close valve that opens and closes in a flow path that returns the used refrigerant gas to the compressor 1.

  The regenerator 5 is filled with a regenerator material that exchanges heat with refrigerant gas that reciprocates inside, and the high-temperature end of the regenerator 5 is connected to the intake valve 2 (V1) and the exhaust valve 3 (V2) via the supply / exhaust pipe 4. ) And the high temperature end of the pulse tube 8, and the low temperature end communicates with the low temperature end of the pulse tube 8 via the cooling stage 7.

  The double inlet pipe 6 communicates with the supply valve 2 (V 1) and the exhaust valve 3 (V 2) (or the high temperature end of the regenerator 5) and the high temperature end of the pulse tube 8.

  The cooling stage 7 is provided in a flow path that communicates with the low temperature end of the regenerator 5 and the low temperature end of the pulse tube 8, and cools the object to be cooled by the cold generated in the cooling cycle.

  The pulse tube 8 is a hollow cylinder that generates cold when refrigerant gas expands inside, and the high temperature end is connected to the supply valve 2 (V1) and the exhaust valve 3 (V2) via the double inlet pipe 6. In addition to being communicated (or to the high temperature end of the regenerator 5), it communicates with the buffer tank 10 via the orifice pipe 9, and the low temperature end communicates with the low temperature end of the regenerator 5 via the cooling stage 7.

  The orifice pipe 9 communicates with the high temperature end of the pulse tube 8 and the buffer tank 10.

  The buffer tank 10 constitutes an intermediate pressure source and communicates with the high temperature end of the pulse tube 8 via the orifice pipe 9.

  The double inlet flow rate adjusting unit 11 is provided in the double inlet pipe 6 and adjusts the flow rate of the refrigerant gas flowing through the double inlet pipe 6.

  The orifice flow rate adjusting unit 12 is provided in the orifice pipe 9 and adjusts the flow rate of the refrigerant gas flowing through the orifice pipe 9.

  In particular, the double inlet pipe 6 is provided with a double inlet on / off valve 13 (V3) that opens and closes in synchronization with the periodic opening and closing of the air supply valve 2 (V1) and the exhaust valve 3 (V2). The orifice pipe 9 is provided with an orifice opening / closing valve 14 (V4) that opens and closes in synchronization with the periodic opening and closing operations of the air supply valve 2 (V1) and the exhaust valve 3 (V2).

  The control device 100 periodically opens and closes the supply valve 2 (V1), the exhaust valve 3 (V2), the double inlet on-off valve 13 (V3), and the orifice on-off valve 14 (V4) according to a predetermined sequence. By controlling, the refrigeration cycle in the pulse tube refrigerator is carried out.

  The supply valve 2 (V1), the exhaust valve 3 (V2), the double inlet on-off valve 13 (V3), and the orifice on-off valve 14 (V4) may be housed in one mechanical on-off valve. Good. For example, the four open / close valves can be periodically opened / closed by one rotary valve or one spool valve. In that case, the apparatus can be reduced in size.

  Next, with reference to FIG. 2, the refrigerating cycle in the pulse tube refrigerator of this embodiment is demonstrated.

  In the pulse tube refrigerator according to the present embodiment, as shown in FIG. 2, four on-off valves, that is, an air supply valve 2 (V1), an exhaust valve 3 (V2), a double inlet on-off valve 13 (V3), A refrigeration cycle is performed in which the orifice on / off valve 14 (V4) periodically opens and closes.

  First, the supply valve 2 (V1) and the double inlet on / off valve 13 (V3) are opened almost simultaneously from the state in which all the four on-off valves are closed. Thereby, the high-pressure refrigerant gas compressed by the compressor 1 is introduced into the refrigerator cold head from both sides of the high temperature end of the regenerator 5 and the high temperature end of the pulse tube 8. At this time, since the orifice on-off valve 14 (V4) is closed, it becomes possible to prevent an invalid compressed gas flow as shown in FIG. 3 and form an ideal compressed gas flow. At this time, the flow rate adjusting unit 11 functions as a fixed or semi-fixed pressure loss unit that adjusts the amount of refrigerant gas introduced from the double inlet pipe 6 to the pulse pipe 8. Instead of providing the pressure adjusting unit 9, the flow rate may be adjusted by the pressure loss of the double inlet pipe 6 instead.

  The double inlet on / off valve 13 (V3) is closed before the air supply valve 2 (V1) is closed, and then the orifice on / off valve 14 (V4) is opened. After the high-pressure gas moves in the direction of the regenerator 5 → the cooling stage 7 → the pulse tube 8, the air supply valve 2 (V 1) is closed. As a result, the refrigerant gas in the pulse tube 8 flows out to the buffer tank 12 in a state where the refrigerant gas is not supplied, so that the refrigerant gas in the pulse tube 8 expands and the temperature decreases. At this time, since the double inlet on-off valve 13 (V3) is closed, it becomes possible to prevent an invalid compressed gas flow as shown in FIG. 4 and to form an ideal compressed gas flow.

  Thereafter, the orifice on / off valve 14 (V4) is closed, the exhaust valve 3 (V2) and the double inlet on / off valve 13 (V3) are opened almost simultaneously, and the gas in the cold head is reduced to the low pressure side pressure level of the compressor 1. Is done.

  After the decompression is completed, when the double inlet on / off valve 13 (V3) is closed and then the orifice on / off valve 14 (V4) is opened, the refrigerant gas is pushed out in the direction of the pulse tube 8 → the cooling stage 7 → the regenerator 5. After that, when the exhaust valve 3 (V2) is closed and the orifice on-off valve 14 (V4) is closed, the state immediately before the pressure increasing process for opening V1 and V3 shown first is reached, and one cycle of the refrigeration cycle is completed.

  According to the first embodiment, in the orifice / double inlet type pulse tube refrigerator, the flow of the refrigerant gas that does not contribute to the generation of cold and is an inefficient factor can be suppressed, so that the refrigerating capacity is improved. Can do.

  In the present embodiment, the case where both the double inlet on-off valve 13 (V3) and the orifice on-off valve 14 (V4) are provided is illustrated, but the double inlet on-off valve 13 (V3) and the orifice on-off valve 14 (V4) are provided. It is good also as a structure in which any one of these is provided. Even in this case, the refrigerating capacity can be improved.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the element which is common in the above-mentioned 1st Embodiment, and the overlapping description is abbreviate | omitted.

  In the second embodiment, in addition to the above-described control of the four open / close valves, the open / close timing of the double inlet open / close valve 13 (V3) and the orifice open / close valve 14 (V4) according to the temperature of the cooling stage 7. Alternatively, control for changing the volume of the buffer tank 10 or the internal gas temperature of the buffer tank 10 is performed.

  FIG. 5 is a configuration diagram showing a schematic configuration of a pulse tube refrigerator according to the second embodiment of the present invention.

  As shown in FIG. 5, the pulse tube refrigerator according to the second embodiment includes a temperature sensor 21, a buffer tank volume control mechanism 22, and a buffer tank temperature control mechanism 23 in addition to the components shown in FIG. I have. Only one of the buffer tank volume control mechanism 22 and the buffer tank temperature control mechanism 23 may be provided.

  The temperature sensor 21 is installed on the cooling stage 7 and detects the temperature of the cooling stage 7. The result detected by the temperature sensor 21 is transmitted as a detection signal to the control device 100A.

  The buffer tank volume control mechanism 22 is a mechanism that increases or decreases the volume of the buffer tank 10.

  The buffer tank temperature control mechanism 23 is a mechanism that changes the temperature of the internal gas of the buffer tank 10.

  The control device 100A has a function of controlling the opening / closing operations of the air supply valve 2 (V1), the exhaust valve 3 (V2), the double inlet on / off valve 13 (V3), and the orifice on / off valve 14 (V4) as described above. The following functions are provided.

  The control device 100A monitors the detection signal of the temperature sensor 21 during the operation of the refrigerator, and increases the volume of the buffer tank 10 through the buffer tank volume control mechanism 22 in conjunction with the temperature increase / decrease in temperature of the cooling stage 7. A function of reducing or increasing the temperature of the internal gas of the buffer tank 10 through the buffer tank temperature control mechanism 23 or increasing both of them is provided.

  Further, the control device 100A controls the double inlet on-off valve 13 (V3) in conjunction with the temperature increase / decrease of the cooling stage 7 during the operation of the refrigerator, instead of controlling the volume of the buffer tank 10 and the internal gas temperature. ) Is shortened / longened, or the orifice open / close valve 14 (V4) is opened / shortened, or both of them are implemented. When this function is used, it is not necessary to install the buffer tank volume control mechanism 22 and the buffer tank temperature control mechanism 23.

  That is, in the present embodiment, when the cooling temperature in the cooling stage 7 is high, the temperature gradient of the pulse tube 8 is small. For example, the volume of the buffer tank 10 is increased or the refrigerant gas in the buffer tank 10 is increased. The amount of expansion gas from the orifice pipe 9 into the buffer tank 10 is increased by performing control such as lowering the temperature or increasing the time during which the orifice opening / closing valve 14 (V4) is open. Even if the expansion volume of the refrigerant gas is increased, the refrigeration loss such as the shuttle loss is small, so that the efficiency can be improved. In addition, when the cooling temperature at the cooling stage 7 is high, the flow rate of the refrigerant gas flowing into the refrigerator is small. Therefore, in order to increase the flow rate, control is performed to shorten the time during which the double inlet on / off valve is open. It is also effective to suppress gas inflow from the double inlet on-off valve 13 (V3).

  FIG. 6 shows an example of the refrigeration cycle when the time during which the orifice opening / closing valve 14 (V4) is open is extended when the temperature of the cooling stage 7 is high.

  As shown in FIG. 6, the time during which the orifice opening / closing valve 14 (V4) is open is longer than that shown in FIG. At this time, the time zone in which the double inlet on-off valve 13 (V3) is open and the time zone in which the orifice on-off valve 14 (V4) is open do not overlap. It should be noted that not only the time during which the orifice on / off valve 14 (V4) is open, but also the time during which the double inlet on / off valve 13 (V3) is open may be shortened.

  According to the second embodiment, when the temperature of the cooling stage is high, the control for realizing the high-efficiency operation according to the temperature is performed, so that the refrigerating capacity is further improved, for example, the initial temperature from room temperature The cooling time in the precooling process can also be shortened.

(Third embodiment)
Next, a third embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the element which is common in the above-mentioned 2nd Embodiment, and the overlapping description is abbreviate | omitted.

  In the third embodiment, a superconducting magnet apparatus using the orifice / double inlet type pulse tube refrigerator described in the second embodiment (FIG. 5) will be described.

  FIG. 7 is a configuration diagram showing a schematic configuration of a superconducting magnet apparatus according to the third embodiment of the present invention.

  The superconducting magnet apparatus according to the third embodiment constitutes a system for cooling the superconducting coil 31 using the orifice / double inlet type pulse tube refrigerator described in the second embodiment (FIG. 5). Yes.

  The cooling stage 7 of the refrigerator is connected to the superconducting coil 31 through a heat transfer plate 32. The above-described temperature sensor 21 is installed in the superconducting coil 31, and the result detected by the temperature sensor 21 is transmitted as a detection signal to the control device 100B.

  The control device 100B monitors the detection signal of the temperature sensor 21, and increases / decreases the volume of the buffer tank 10 in conjunction with the temperature increase / decrease in temperature of the superconducting coil due to quenching of the superconducting magnet, or the inside of the buffer tank. It has the function of lowering / increasing the temperature of the gas, or both.

  Furthermore, instead of controlling the volume of the buffer tank 10 and the internal gas temperature, the control device 100B monitors the detection signal of the temperature sensor 21 and interlocks with the temperature increase / temperature decrease of the superconducting coil 31 due to quenching of the superconducting magnet. Thus, the opening / closing time of the orifice opening / closing valve 14 (V4) is lengthened / shortened, or the opening time of the double inlet opening / closing valve 13 (V3) is shortened / lengthened, or both of them are performed. It has a function. When this function is used, it is not necessary to install the buffer tank volume control mechanism 22 and the buffer tank temperature control mechanism 23.

  An example of the refrigeration cycle is as described in the second embodiment.

  According to the third embodiment, when the temperature of the superconducting coil is high, control for realizing highly efficient operation according to the temperature is performed, so that the refrigerating capacity is further improved, for example, the initial temperature from room temperature. In addition to shortening the cooling time in the precooling process, the return time after quenching of the superconducting coil can be shortened when the temperature of the superconducting coil is quenched during cooling of the superconducting magnet.

  As described above in detail, according to each embodiment of the present invention, it is possible to improve cooling efficiency in an orifice / double inlet type pulse tube refrigerator and a superconducting magnet apparatus using the same.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 1 ... Regenerator, 2 ... Supply valve (V1), 3 ... Exhaust valve (V2), 4 ... Supply / exhaust piping, 5 ... Regenerator, 6 ... Double inlet piping, 7 ... Cooling stage, 8 ... Pulse tube, 9 ... Orifice piping, 10 ... Buffer tank, 11 ... Double inlet flow rate adjustment unit, 12 ... Orifice flow rate adjustment unit, 13 ... Double inlet on / off valve (V3), 14 ... Orifice on / off valve (V4), 21 ... Temperature sensor, 22 ... Buffer tank volume control mechanism, 23 ... Buffer tank temperature control mechanism, 31 ... Superconducting coil, 32 ... Heat transfer plate, 100, 100A, 100B ... Control device.

Claims (15)

A compressor for compressing refrigerant gas;
An air supply valve that opens and closes in a flow path for supplying refrigerant gas compressed by the compressor;
An exhaust valve that opens and closes in a flow path for returning the used refrigerant gas to the compressor;
A regenerator that communicates with the air supply valve and the exhaust valve via a supply / exhaust pipe;
A pulse tube communicating with the air supply valve and the exhaust valve via a double inlet pipe, and communicating with a low temperature end of the regenerator via a cooling stage;
A buffer tank communicating with the high temperature end of the pulse tube through an orifice pipe;
A pulse tube refrigerator, wherein the orifice pipe is provided with an orifice opening / closing valve that opens and closes in synchronization with a periodic opening / closing operation of the air supply valve and the exhaust valve. In the pulse tube refrigerator according to claim 1,
The orifice open / close valve is closed before the air supply valve is opened, is opened before the air supply valve is closed, is closed before the exhaust valve is opened, and is opened before the exhaust valve is closed. refrigerator. In the pulse tube refrigerator according to claim 1 or 2,
A pulse tube refrigerator comprising means for extending the time during which the orifice on-off valve is open in conjunction with a rise in temperature of the cooling stage during operation of the refrigerator. A compressor for compressing refrigerant gas;
An air supply valve that opens and closes in a flow path for supplying refrigerant gas compressed by the compressor;
An exhaust valve that opens and closes in a flow path for returning the used refrigerant gas to the compressor;
A regenerator that communicates with the air supply valve and the exhaust valve via a supply / exhaust pipe;
A pulse tube communicating with the air supply valve and the exhaust valve via a double inlet pipe, and communicating with a low temperature end of the regenerator via a cooling stage;
A buffer tank communicating with the high temperature end of the pulse tube through an orifice pipe;
A pulse tube refrigerator, wherein the double inlet pipe is provided with a double inlet on / off valve that opens and closes in synchronization with the periodic opening and closing of the air supply valve and the exhaust valve. In the pulse tube refrigerator according to claim 4,
The double inlet open / close valve opens substantially simultaneously with the opening of the air supply valve, closes before the air supply valve closes, opens approximately simultaneously with the opening of the exhaust valve, and closes before the exhaust valve closes. A featured pulse tube refrigerator. In the pulse tube refrigerator according to claim 4 or 5,
A pulse tube refrigerator comprising means for shortening a time during which the double inlet on-off valve is open in conjunction with an increase in temperature of the cooling stage during operation of the refrigerator. A compressor for compressing refrigerant gas;
An air supply valve that opens and closes in a flow path for supplying refrigerant gas compressed by the compressor;
An exhaust valve that opens and closes in a flow path for returning the used refrigerant gas to the compressor;
A regenerator that communicates with the air supply valve and the exhaust valve via a supply / exhaust pipe;
A pulse tube communicating with the air supply valve and the exhaust valve via a double inlet pipe, and communicating with a low temperature end of the regenerator via a cooling stage;
A buffer tank communicating with the high temperature end of the pulse tube through an orifice pipe;
The orifice piping is provided with an orifice opening / closing valve that opens and closes in synchronization with the periodic opening and closing operations of the air supply valve and the exhaust valve,
A pulse tube refrigerator, wherein the double inlet pipe is provided with a double inlet on / off valve that opens and closes in synchronization with the periodic opening and closing of the air supply valve and the exhaust valve. In the pulse tube refrigerator according to claim 7,
The orifice opening / closing valve is closed before the air supply valve is opened, opened before the air supply valve is closed, closed before the exhaust valve is opened, and opened before the exhaust valve is closed,
The double inlet open / close valve opens substantially simultaneously with the opening of the air supply valve, closes before the air supply valve closes, opens approximately simultaneously with the opening of the exhaust valve, and closes before the exhaust valve closes. A featured pulse tube refrigerator. In the pulse tube refrigerator according to any one of claims 1 to 8,
A pulse tube refrigerator characterized in that a periodic opening / closing operation of each valve is realized by one rotary valve or one spool valve. In the pulse tube refrigerator according to any one of claims 1 to 9,
A pulse tube refrigerator comprising means for changing the volume of the buffer tank or the temperature of the internal gas of the buffer tank during operation of the refrigerator. In the pulse tube refrigerator according to any one of claims 1 to 10,
A means for increasing the volume of the buffer tank, or lowering the temperature of the internal gas of the buffer tank, or both in conjunction with the temperature rise of the cooling stage during operation of the refrigerator; The pulse tube refrigerator characterized by having.   A superconducting magnet device, wherein the superconducting coil is cooled using the pulse tube refrigerator according to any one of claims 1 to 11. A superconducting magnet apparatus for cooling a superconducting coil using the pulse tube refrigerator according to any one of claims 1 to 3 and 7 to 11.
A superconducting magnet device comprising means for extending the time during which the orifice on-off valve is open in conjunction with a temperature rise of the superconducting coil. In the superconducting magnet apparatus that cools the superconducting coil using the pulse tube refrigerator according to any one of claims 4 to 11,
A superconducting magnet device comprising means for shortening a time during which the double inlet on-off valve is open in conjunction with a temperature rise of the superconducting coil. The superconducting magnet device according to any one of claims 12 to 14,
Superconductivity characterized by comprising means for enlarging the volume of the buffer tank and / or lowering the temperature of the internal gas of the buffer tank in conjunction with a rise in the temperature of the superconducting coil. Magnet device.

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