CN108109806A - Superconducting magnet apparatus - Google Patents
Superconducting magnet apparatus Download PDFInfo
- Publication number
- CN108109806A CN108109806A CN201711200771.5A CN201711200771A CN108109806A CN 108109806 A CN108109806 A CN 108109806A CN 201711200771 A CN201711200771 A CN 201711200771A CN 108109806 A CN108109806 A CN 108109806A
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- Prior art keywords
- working medium
- heat exchange
- heat exchanger
- cooling
- superconducting coil
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- 238000001816 cooling Methods 0.000 claims abstract description 122
- 230000005855 radiation Effects 0.000 claims description 27
- 239000002826 coolant Substances 0.000 claims description 16
- 238000010438 heat treatment Methods 0.000 claims description 16
- 238000011144 upstream manufacturing Methods 0.000 claims description 12
- 238000005057 refrigeration Methods 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 65
- 239000001307 helium Substances 0.000 description 55
- 229910052734 helium Inorganic materials 0.000 description 55
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 55
- 239000012071 phase Substances 0.000 description 9
- 238000012423 maintenance Methods 0.000 description 7
- 239000007792 gaseous phase Substances 0.000 description 6
- 238000001514 detection method Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000004804 winding Methods 0.000 description 3
- 239000007788 liquid Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000002887 superconductor Substances 0.000 description 1
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F6/00—Superconducting magnets; Superconducting coils
- H01F6/04—Cooling
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
- F25B9/14—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the cycle used, e.g. Stirling cycle
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F6/00—Superconducting magnets; Superconducting coils
- H01F6/006—Supplying energising or de-energising current; Flux pumps
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F6/00—Superconducting magnets; Superconducting coils
- H01F6/06—Coils, e.g. winding, insulating, terminating or casing arrangements therefor
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Containers, Films, And Cooling For Superconductive Devices (AREA)
Abstract
The superconducting magnet apparatus of the present invention includes：Superconducting coil；Vacuum tank；Refrigeration machine includes the first refrigerating head, the second refrigerating head and attached portion；Flow of operating medium includes the first heat exchange department, the second heat exchange department and the 3rd heat exchange department；Heat exchanger makes by the first refrigerating head working media after cooling and cools the working media after superconducting coil and carry out heat exchange；Heat exchanger tortuous flow passage makes position of the working media of gas phase from flow of operating medium between the 3rd heat exchange department and heat exchanger export to outside vacuum tank.Thereby, it is possible to shorten that superconducting coil is made to be cooled to the superconducting coil as the pre-coo time needed for superconducting state.
Description
Technical Field
The present invention relates to a superconducting magnet device.
Background
Conventionally, the following superconducting magnet devices are known: the superconducting coil can be made to be in a superconducting state by cooling the superconducting coil with a gaseous working medium (helium gas or the like) by a refrigerator. For example, japanese patent laid-open publication No. 2015-12193 (hereinafter referred to as patent document 1) discloses a superconducting magnet apparatus including: a superconducting coil; a vacuum vessel for accommodating the superconducting coil; a GM refrigerator attached to the vacuum vessel; a gas circulation compressor which is disposed outside the vacuum container and compresses a working medium (gas) in a gas phase; a first pipe for circulating gas; and a heat exchanger provided in the first pipe. The GM refrigerator has a first cooling head and a second cooling head. The first pipe is in thermal contact with the first cooling head, the second cooling head, and the superconducting coil. The heat exchanger exchanges heat between the working medium cooled by the first cooling head, which flows through the first pipe between the first cooling head and the second cooling head, and the working medium cooled by the first cooling head, which flows through the first pipe between the superconducting coil and the gas circulation compressor.
In this superconducting magnet device, the working medium in a gaseous phase circulates in the first pipe, and the superconducting coil is maintained in a superconducting state. Specifically, the superconducting coil is cooled by the working medium cooled by the cooling heads of the refrigerator. The working medium cooled by the superconducting coil is heated in the heat exchanger. Therefore, the working medium having a temperature at or near normal temperature flows into the gas circulation compressor located outside the vacuum vessel.
However, there is a need for a superconducting magnet device described in patent document 1 that reduces the initial pre-cooling time required to cool a superconducting coil from a temperature such as room temperature to a temperature at which the superconducting coil becomes a superconducting state.
Disclosure of Invention
An object of the present invention is to provide a superconducting magnet device including: the pre-cooling time required for cooling the superconducting coil until the superconducting coil becomes a superconducting state can be shortened.
A superconducting magnet device according to the present invention includes: a superconducting coil; a vacuum container for accommodating the superconducting coil; a refrigerator including a first cooling head, a second cooling head capable of reaching a temperature lower than a temperature that the first cooling head can reach, and a mounted portion mounted to the vacuum container in a state where the first cooling head and the second cooling head are positioned in the vacuum container; a working medium flow path including a first heat exchange portion in thermal contact with the first coolant header, a second heat exchange portion in thermal contact with the second coolant header, and a third heat exchange portion in thermal contact with the superconducting coil, the working medium flow path flowing a gas-phase working medium in the order of the first heat exchange portion, the second heat exchange portion, and the third heat exchange portion; a heat exchanger that exchanges heat between the working medium cooled by the first cooling head and the working medium cooled by the superconducting coil; and a heat exchanger bypass flow path that leads the gaseous working medium out of the vacuum chamber from a portion of the working medium flow path located between the third heat exchanger and the heat exchanger.
According to the present invention, the precooling time required for cooling the superconducting coil until the superconducting coil becomes a superconducting state can be shortened.
Drawings
Fig. 1 is a schematic cross-sectional view showing a superconducting magnet device according to an embodiment of the present invention.
Fig. 2 is a diagram showing the flow of the working medium in the steady-state operation of the superconducting magnet device shown in fig. 1.
Fig. 3 is a diagram showing the flow of the working medium during the precooling operation of the superconducting magnet apparatus shown in fig. 1.
Fig. 4 is a diagram showing the flow of the working medium during the refrigerator temperature increasing operation of the superconducting magnet device shown in fig. 1.
Detailed Description
A superconducting magnet device according to an embodiment of the present invention will be described below with reference to fig. 1 to 4.
As shown in fig. 1, a superconducting magnet apparatus 1 includes: a superconducting coil 10; a radiation shield 12; a vacuum vessel 14; a refrigerator 20; a working medium flow path 30; a pump 40; a first heat exchanger 41 and a second heat exchanger 42; a heat exchanger bypass passage 54; a coil detour passage 56; a switching unit 60.
The superconducting coil 10 is a coil obtained by winding a wire material made of a superconductor (superconducting material) around a bobbin.
The radiation shield 12 has a shape that accommodates the superconducting coil 10. The radiation shield 12 is formed of aluminum.
The vacuum vessel 14 has a shape that houses the radiation shield 12. The vacuum vessel 14 is maintained at a vacuum. This can suppress the intrusion of heat into the vacuum chamber 14. The vacuum vessel 14 is formed of stainless steel.
The refrigerator 20 cools the superconducting coil 10 by the working medium in the gas phase. The refrigerator 20 includes a first cooling head (cooling stage)21, a second cooling head 22, and a mounted portion 23.
The first cooling head 21 is thermally connected to the radiation shield 12. The first cooling head 21 is able to reach a first minimum reaching temperature (of the order of 40K to 70K).
The second cold head 22 is located within the radiation shield 12. The second cooling head 22 is able to reach a second minimum reaching temperature (of the order of 4K) lower than the first minimum reaching temperature.
The attached portion 23 is attached to the vacuum chamber 14 so as to be detachable from the vacuum chamber 14 in a state where the first cooling head 21 and the second cooling head 22 are positioned in the vacuum chamber 14.
The working medium flow path 30 is a flow path through which a gaseous working medium (helium gas, hydrogen gas, or the like) flows. In the present embodiment, the working medium flow path 30 has a shape that circulates the working medium in a gas phase inside the vacuum chamber 14 and outside the vacuum chamber 14. The working medium flow path 30 includes a first heat exchange unit 31, a second heat exchange unit 32, and a third heat exchange unit 33. The first heat exchange portion 31 is in thermal contact with the first coolant header 21. The second heat exchanging portion 32 is in thermal contact with the second coolant header 22. Third heat exchanging portion 33 is in thermal contact with superconducting coil 10. That is, first heat exchange portion 31 and second heat exchange portion 32 constitute a "refrigerator heat exchange portion" in thermal contact with refrigerator 20, and third heat exchange portion 33 constitutes a "coil heat exchange portion" in thermal contact with superconducting coil 10. In the present embodiment, helium gas is used as the working medium in the gas phase.
A pump 40 for sending the helium gas flowing out of the vacuum chamber 14 to the first heat exchange unit 31 through the working medium flow path 30 is provided in a portion of the working medium flow path 30 located outside the vacuum chamber 14. A first opening/closing valve V1, a first flow sensor F1, and a safety valve RV, which are capable of adjusting the opening degree, are provided in the working medium flow path 30 at a position outside the vacuum chamber 14 and downstream of the pump 40. A second on-off valve V2 and a second flow sensor F2, which are adjustable in opening degree, are provided in the working medium flow path 30 at a position outside the vacuum chamber 14 and upstream of the pump 40.
The first heat exchanger 41 is disposed within the radiation shield 12. The first heat exchanger 41 exchanges heat between the helium gas after the first heat exchange portion 31 is cooled by the first coolant head 21 and before the second heat exchange portion 32 is cooled by the second coolant head 22, and the helium gas after the superconducting coil 10 is cooled by the third heat exchange portion 33.
The second heat exchanger 42 is disposed within the vacuum vessel 14 and outside the radiation shield 12. The second heat exchanger 42 exchanges heat between the helium gas before flowing into the first heat exchange unit 31 and the helium gas after passing through the first heat exchanger 41.
In the present embodiment, superconducting magnet device 1 has cooling flow path 52 for cooling radiation shield 12. The cooling channel 52 is connected to the working medium channel 30. Specifically, the upstream end of the cooling passage 52 is connected to a portion of the working medium passage 30 that is located downstream of the first heat exchanger 31 and upstream of the first heat exchanger 41. The end of the cooling passage 52 on the downstream side is connected to a portion of the working medium passage 30 located on the outer side of the vacuum chamber 14 and on the upstream side of the pump 40. The cooling flow path 52 has a cooling portion 53 in thermal contact with the radiation shield 12. Therefore, the radiation shield 12 is cooled in the cooling portion 53 based on the cold energy (cold energy) received from the helium gas, which is the cold energy received from the first cooling head 21 in the first heat exchange portion 31. The cooling flow path 52 passes through the interior of the second heat exchanger 42. Therefore, the helium gas flowing from the outside of the vacuum chamber 14 to the first heat exchange unit 31 through the working medium flow path 30 is cooled by the helium gas flowing through the cooling flow path 52 in the second heat exchanger 42. A third opening/closing valve V3 and a third flow sensor F3, which are capable of adjusting the opening degree, are provided in the cooling passage 52 at a position outside the vacuum chamber 14. Thus, the flow rate of the helium gas flowing through the cooling passage 52 is adjusted by adjusting the respective opening degrees of the first opening/closing valve V1, the second opening/closing valve V2, and the third opening/closing valve V3 based on the detection values of the first flow sensor F1 to the third flow sensor F3.
The heat exchanger bypass passage 54 is a passage used for precooling the superconducting coil 10. The heat exchanger bypass passage 54 is a passage through which the helium gas having passed through the third heat exchange unit 33 bypasses the heat exchangers 41 and 42. Specifically, the heat exchanger bypass passage 54 is a passage through which the helium gas is led out from the portion of the working medium passage 30 located between the third heat exchanger 33 and the first heat exchanger 41 to the outside of the vacuum chamber 14. The upstream end of the heat exchanger bypass passage 54 is connected to a portion of the working medium passage 30 that is located downstream of the third heat exchange unit 33 and upstream of the first heat exchanger 41. The downstream end of the heat exchanger bypass passage 54 is connected to a portion of the working medium passage 30 located outside the vacuum chamber 14 and upstream of the pump 40. The heat exchanger bypass passage 54 has a heating unit 55 for heating the helium gas outside the vacuum chamber 14. A fourth opening/closing valve V4 and a fourth flow rate sensor F4, which are adjustable in opening degree, are provided in the heat exchanger bypass passage 54 at a position outside the vacuum chamber 14 and downstream of the heating unit 55.
The coil bypass flow path 56 is a flow path used for maintenance of the refrigerator 20. The coil bypass flow path 56 is a flow path for bypassing the helium gas passing through the second heat exchange unit 32 around the third heat exchange unit 33. Specifically, the coil bypass passage 56 is a passage through which the helium gas is led out from the working medium passage 30 to the outside of the vacuum chamber 14 through a portion located between the second heat exchange unit 32 and the third heat exchange unit 33. The upstream end of the coil winding flow path 56 is connected to a portion of the working medium flow path 30 located between the second heat exchange unit 32 and the third heat exchange unit 33. The downstream end of the coil winding flow path 56 is connected to a portion of the working medium flow path 30 located outside the vacuum chamber 14 and upstream of the pump 40. The coil bypass passage 56 has a heating portion 57 for heating the helium gas outside the vacuum chamber 14. A fifth opening/closing valve V5 and a fifth flow rate sensor F5, which are capable of adjusting the opening degree, are provided in the coil bypass passage 56 at a position outside the vacuum chamber 14 and downstream of the heating unit 57.
Here, the operation of the superconducting magnet device 1 described above in the steady state operation will be described. In steady operation, first on-off valve V1, second on-off valve V2, and third on-off valve V3 are opened, fourth on-off valve V4 and fifth on-off valve V5 are closed, superconducting coil 10 is energized, and refrigerator 20 and pump 40 are driven. In this steady state operation, as shown in fig. 2, a part of the helium gas discharged from the pump 40 circulates through the working medium flow path 30, and the remaining part of the helium gas discharged from the pump 40 circulates through the working medium flow path 30 via the cooling flow path 52. That is, a part of the helium gas flows through the second heat exchanger 42, the first heat exchange unit 31, the first heat exchanger 41, the second heat exchange unit 32, the third heat exchange unit 33, the first heat exchanger 41, and the second heat exchanger 42 in this order, and the remaining part of the helium gas flows through the second heat exchanger 42, the first heat exchange unit 31, the cooling unit 53, and the second heat exchanger 42 in this order.
After the first heat exchange unit 31 receives cooling energy from the first cooling head 21, a part of the helium gas receives further cooling energy from the second cooling head 22 in the second heat exchange unit 32, and the received cooling energy is applied to the superconducting coil 10 in the third heat exchange unit 33. Thereby, superconducting coil 10 is cooled. Thus, the superconducting coil 10 is maintained in a superconducting state. The helium gas having passed through the third heat exchange unit 33 is heated by the helium gas flowing to the third heat exchange unit 33 in the first heat exchanger 41 and the second heat exchanger 42. Accordingly, the temperature of the helium gas passing through the second heat exchanger 42 becomes a temperature (e.g., a room temperature level) at which the pump 40 can be stably driven. This stabilizes the driving of the pump 40.
The remaining part of the helium gas receives the cooling energy from the first cooling header 21 in the first heat exchange unit 31, and then the cooling energy is applied to the radiation shield 12 in the cooling unit 53. Thereby, the radiation shield 12 is cooled. Therefore, the radiation shield 12 can be cooled more efficiently than in the case where the radiation shield 12 is cooled only by the first cooling head 21. The helium gas having passed through the cooling unit 53 is heated by the helium gas flowing into the first heat exchange unit 31 in the second heat exchanger 42. Accordingly, the temperature of the helium gas passing through the second heat exchanger 42 becomes a temperature (e.g., a room temperature level) at which the pump 40 can be stably driven.
In this steady-state operation, as described above, the flow rate of the helium gas flowing through the cooling passage 52 is adjusted by adjusting the respective opening degrees of the first opening/closing valve V1, the second opening/closing valve V2, and the third opening/closing valve V3 based on the detection values of the first flow sensor F1 to the third flow sensor F3.
Next, the switching unit 60 will be described. The switching unit 60 performs the following operations: an operation of switching the operation from the precooling operation to the steady-state operation; and switching the operation from the steady-state operation to the refrigerator warm-up operation. The pre-cooling operation is an operation for cooling superconducting coil 10 from, for example, a normal temperature in order to bring superconducting coil 10 into a superconducting state. The refrigerator temperature increasing operation is an operation of increasing the temperature of the refrigerator 20 when the refrigerator 20 is maintained.
First, the precooling operation is explained. In the pre-cooling operation, the first opening/closing valve V1, the third opening/closing valve V3, and the fourth opening/closing valve V4 are opened, the second opening/closing valve V2, and the fifth opening/closing valve V5 are closed, and the refrigerator 20 and the pump 40 are driven. In this pre-cooling operation, as shown in fig. 3, a part of the helium gas discharged from the pump 40 circulates through the working medium flow path 30 via the heat exchanger bypass flow path 54, and the remaining part of the helium gas discharged from the pump 40 circulates through the working medium flow path 30 via the cooling flow path 52. That is, a part of the helium gas flows through the second heat exchanger 42, the first heat exchange unit 31, the first heat exchanger 41, the second heat exchange unit 32, the third heat exchange unit 33, and the heating unit 55 in this order, and the remaining part of the helium gas flows through the second heat exchanger 42, the first heat exchange unit 31, the cooling unit 53, and the second heat exchanger 42 in this order.
After the first heat exchange unit 31 receives cooling energy from the first cooling head 21, a part of the helium gas receives further cooling energy from the second cooling head 22 in the second heat exchange unit 32, and the received cooling energy is applied to the superconducting coil 10 in the third heat exchange unit 33. Thereby, superconducting coil 10 is cooled. In the precooling operation, unlike the steady-state operation, the helium gas that has passed through the third heat exchange unit 33 bypasses the first heat exchanger 41 and the second heat exchanger 42 through the heat exchanger bypass passage 54 and returns to the pump 40. Therefore, the helium gas flowing from the first heat exchange portion 31 to the second heat exchange portion 32 can be prevented from being heated by the helium gas after passing through the third heat exchange portion 33 in the first heat exchanger 41. In other words, it is possible to avoid a situation in which the cooling energy received by the helium gas from first cooling head 21 is lost before being imparted to superconducting coil 10. This enables the cooling energy obtained from the cooling heads 21 and 22 to be efficiently applied to the superconducting coil 10, and the precooling time of the superconducting coil 10 can be shortened.
The helium gas flowing into the heat exchanger bypass passage 54 is heated by the heating unit 55. Accordingly, the temperature of the helium gas passing through the heating unit 55 becomes a temperature (e.g., a room temperature level) at which the pump 40 can be stably driven.
In this precooling operation, the volume of helium gas decreases as cooling of superconducting coil 10 proceeds. When the pressure of the working medium flow path 30 is lower than the threshold value, the helium gas is replenished from the storage container 71 storing the helium gas to the working medium flow path 30 through the replenishing flow path 72 until the pressure of the working medium flow path 30 becomes equal to or higher than the threshold value. The pressure of the working medium flow path 30 is measured by a pressure sensor 73 provided at a portion of the working medium flow path 30 located on the upstream side of the pump 40. The helium gas may be manually supplied to the working medium flow path 30 based on the detection value of the pressure sensor 73, or the pressure regulator may be used when the storage container 71 is provided with a pressure regulator.
After the pre-cooling operation is completed, that is, after the temperature of superconducting coil 10 reaches the reference value (critical temperature), switching unit 60 performs an operation of switching from the pre-cooling operation to the steady-state operation (operation of returning the helium gas to pump 40 via first heat exchanger 41 and second heat exchanger 42 after passing through third heat exchange unit 33). Specifically, when the temperature of the superconducting coil 10 reaches the reference value, the switching unit 60 closes the fourth opening/closing valve V4 and opens the third opening/closing valve V3, thereby energizing the superconducting coil 10. The temperature of superconducting coil 10 is measured by temperature sensor 63 provided in superconducting coil 10.
Next, the refrigerator temperature increasing operation will be described. This refrigerator warm-up operation is performed at the time of maintenance of the refrigerator 20. In the refrigerator temperature increasing operation, the first on-off valve V1 and the fifth on-off valve V5 are opened, the second on-off valve V2, the third on-off valve V3, and the fourth on-off valve V4 are closed, the pump 40 is driven, and the refrigerator 20 is stopped. In this refrigerator temperature increasing operation, as shown in fig. 4, the helium gas discharged from the pump 40 circulates through the working medium flow path 30 via the coil bypass flow path 56. That is, the helium gas flows through the second heat exchanger 42, the first heat exchanger 31, the first heat exchanger 41, the second heat exchanger 32, and the heating unit 57 in this order. At this time, the helium gas of the room temperature flowing into the vacuum chamber 14 heats the first cooling head 21 in the first heat exchange unit 31, and then heats the second cooling head 22 in the second heat exchange unit 32. This causes the refrigerator 20 to rapidly increase in temperature. In the refrigerator temperature increasing operation, since the refrigerator 20 is stopped, the temperature of the helium gas passing through the second heat exchange portion 32 is higher than the critical temperature of the superconducting coil 10, but the helium gas flows into the coil bypass passage 56 without passing through the third heat exchange portion 33 thermally contacting the superconducting coil 10. Therefore, heating of superconducting coil 10 by the helium gas after heating refrigerator 20 can be avoided. That is, in the refrigerator temperature increasing operation of the present embodiment, the temperature of the refrigerator 20 can be rapidly increased while suppressing the temperature increase of the superconducting coil 10.
The refrigerator temperature increasing operation described above is started when the switching unit 60 receives a signal indicating that maintenance of the refrigerator 20 is to be performed during the steady-state operation. That is, when the switching unit 60 receives the signal during the steady operation, the second opening/closing valve V2 and the third opening/closing valve V3 are closed, the fifth opening/closing valve V5 is opened, and the refrigerator 20 is stopped. The signal is transmitted to the switching unit 60 by, for example, a switch operation performed by an operator.
After the temperature of each of the cooling heads 21 and 22 is brought to the normal temperature level by the refrigerator temperature increasing operation, the refrigerator 20 is removed from the vacuum vessel 14, and maintenance of the refrigerator 20 is performed. The temperature of the first coolant head 21 is measured by a temperature sensor 61 provided in the first coolant head 21, and the temperature of the second coolant head 22 is measured by a temperature sensor 62 provided in the second coolant head 22.
During maintenance of the refrigerator 20, the driving of the pump 40 is continued. Thus, the portion (cylinder or the like) holding the refrigerator 20 in the vacuum chamber 14 is continuously heated by the helium gas, and frost adhesion or the like on the portion can be suppressed. After the maintenance of the refrigerator 20 is completed, the refrigerator 20 is mounted to the vacuum vessel 14. Then, the refrigerator 20 is driven, and the fifth opening-closing valve V5 is closed, while the second opening-closing valve V2 and the third opening-closing valve V3 are opened. Accordingly, during maintenance of refrigerator 20, radiation shield 12 and superconducting coil 10, whose temperature naturally rises, are gradually cooled. After that, the superconducting magnet device 1 returns to the steady operation.
The embodiments disclosed in this specification should be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the scope of the summary of the invention, not by the description of the above embodiments, and includes all modifications equivalent to and within the scope defined by the summary of the invention.
For example, the switching unit 60 may be omitted. In this case, switching from the precooling operation to the steady-state operation or switching from the steady-state operation to the refrigerator temperature increasing operation is performed manually.
The cooling channel 52 may be omitted.
The above-described embodiments are summarized below.
The superconducting magnet device of the present embodiment includes: a superconducting coil; a vacuum container for accommodating the superconducting coil; a refrigerator including a first cooling head, a second cooling head capable of reaching a temperature lower than a temperature that the first cooling head can reach, and a mounted portion mounted to the vacuum container in a state where the first cooling head and the second cooling head are positioned in the vacuum container; a working medium flow path including a first heat exchange portion in thermal contact with the first coolant header, a second heat exchange portion in thermal contact with the second coolant header, and a third heat exchange portion in thermal contact with the superconducting coil, the working medium flow path flowing a gas-phase working medium in the order of the first heat exchange portion, the second heat exchange portion, and the third heat exchange portion; a heat exchanger that exchanges heat between the working medium cooled by the first cooling head and the working medium cooled by the superconducting coil; and a heat exchanger bypass flow path that leads the gaseous working medium out of the vacuum chamber from a portion of the working medium flow path located between the third heat exchanger and the heat exchanger.
The superconducting magnet device includes a heat exchanger bypass passage for discharging a gaseous working medium (such as helium gas) obtained by obtaining cooling energy from a refrigerator in a first heat exchange unit and a second heat exchange unit and applying the cooling energy to a superconducting coil (cooling the superconducting coil) in a third heat exchange unit to the outside of a vacuum vessel without passing through a heat exchanger. Therefore, when the superconducting coil is precooled, the gaseous phase working medium cooled (heated by the superconducting coil) is led out of the vacuum chamber through the heat exchanger bypass passage, so that it is possible to avoid a situation where the gaseous phase working medium is lost in the first heat exchange unit by the heat exchanger from the cooling energy obtained from the first cooling head (a situation where the gaseous phase working medium cooled by the first cooling head is heated based on the gaseous phase working medium cooled by the superconducting coil). Therefore, the cooling energy obtained from the respective cooling heads can be efficiently applied to the superconducting coil. This can shorten the precooling time of the superconducting coil.
In this case, it is preferable that the liquid container further include: and a pump disposed outside the vacuum chamber and configured to feed the gaseous working medium flowing out of the vacuum chamber to the first heat exchanger through the working medium passage.
In this way, since the gaseous phase working medium circulates through the first heat exchange unit, the second heat exchange unit, the third heat exchange unit, and the pump, the amount of the working medium necessary for cooling the superconducting coil can be reduced.
In this case, it is preferable that a downstream end of the heat exchanger bypass flow path is connected to a portion of the working medium flow path that is located outside the vacuum chamber and upstream of the pump, and the heat exchanger bypass flow path has a heating portion that heats the working medium outside the vacuum chamber.
In this way, the working medium flowing out of the vacuum chamber from the lead-out flow path can be returned to the working medium flow path, and the working medium can be heated by the heating unit, so that the load on the pump can be reduced.
Preferably, the superconducting magnet device further includes: a radiation shield covering the superconducting coil within the vacuum vessel and thermally connected to the first cooling head; a cooling flow path including a cooling portion in thermal contact with the radiation shield for cooling the radiation shield; wherein the cooling passage leads the gaseous working medium out of the vacuum chamber from a portion of the working medium passage located between the first heat exchanger and the heat exchanger through the cooling unit.
In this way, since the cooling energy obtained from the first coolant head at the first heat exchange portion by the working medium in the gas phase is given to the radiation shield at the cooling portion, the radiation shield can be cooled more effectively than in the case where the radiation shield is cooled only by the first coolant head.
In this case, it is preferable that the liquid container further include: and another heat exchanger disposed between the vacuum container and the radiation shield, and configured to exchange heat between the working medium before flowing into the first heat exchange unit and the working medium after passing through the cooling unit.
In this way, the working medium passing through the cooling unit can be effectively cooled before flowing into the first heat exchange unit.
Preferably, the superconducting magnet device further includes: and a switching unit that performs a pre-cooling operation when the temperature of the superconducting coil is greater than a reference value, the pre-cooling operation being an operation in which the gas-phase working medium flows in the order of the first heat exchange unit, the heat exchanger, the second heat exchange unit, the third heat exchange unit, and the heat exchanger bypass path, the switching unit switching the pre-cooling operation to a steady-state operation when the temperature of the superconducting coil is equal to or less than the reference value, the steady-state operation being an operation in which the gas-phase working medium flows in the order of the first heat exchange unit, the heat exchanger, the second heat exchange unit, the third heat exchange unit, and the heat exchanger.
In this way, since the reference value is set to the temperature at which the superconducting coil is brought into the superconducting state, it is possible to automatically switch from the precooling operation in which the superconducting coil is precooled to the steady-state operation in which the superconducting coil is maintained in the superconducting state.
Claims (6)
1. A superconducting magnet apparatus, characterized by comprising:
a superconducting coil;
a vacuum container for accommodating the superconducting coil;
a refrigerator including a first cooling head, a second cooling head capable of reaching a temperature lower than a temperature that the first cooling head can reach, and a mounted portion mounted to the vacuum container in a state where the first cooling head and the second cooling head are positioned in the vacuum container;
a working medium flow path including a first heat exchange portion in thermal contact with the first coolant header, a second heat exchange portion in thermal contact with the second coolant header, and a third heat exchange portion in thermal contact with the superconducting coil, the working medium flow path flowing a gas-phase working medium in the order of the first heat exchange portion, the second heat exchange portion, and the third heat exchange portion;
a heat exchanger that exchanges heat between the working medium cooled by the first cooling head and the working medium cooled by the superconducting coil;
and a heat exchanger bypass flow path that leads the gaseous working medium out of the vacuum chamber from a portion of the working medium flow path located between the third heat exchanger and the heat exchanger.
2. The superconducting magnet apparatus according to claim 1, further comprising:
and a pump disposed outside the vacuum chamber and configured to feed the gaseous working medium flowing out of the vacuum chamber to the first heat exchanger through the working medium passage.
3. A superconducting magnet arrangement according to claim 2, wherein:
a downstream end of the heat exchanger bypass flow path is connected to a portion of the working medium flow path that is located outside the vacuum chamber and upstream of the pump,
the heat exchanger bypass channel has a heating unit for heating the working medium outside the vacuum chamber.
4. A superconducting magnet apparatus according to any of claims 1 to 3, further comprising:
a radiation shield covering the superconducting coil within the vacuum vessel and thermally connected to the first cooling head;
a cooling flow path including a cooling portion in thermal contact with the radiation shield for cooling the radiation shield; wherein,
the cooling passage leads the gaseous working medium out of the vacuum chamber from a portion of the working medium passage located between the first heat exchanger and the heat exchanger through the cooling unit.
5. The superconducting magnet apparatus according to claim 4, further comprising:
and another heat exchanger disposed between the vacuum container and the radiation shield, and configured to exchange heat between the working medium before flowing into the first heat exchange unit and the working medium after passing through the cooling unit.
6. The superconducting magnet apparatus according to claim 1, further comprising:
and a switching unit that performs a pre-cooling operation when the temperature of the superconducting coil is greater than a reference value, the pre-cooling operation being an operation in which the gas-phase working medium flows in the order of the first heat exchange unit, the heat exchanger, the second heat exchange unit, the third heat exchange unit, and the heat exchanger bypass path, the switching unit switching the pre-cooling operation to a steady-state operation when the temperature of the superconducting coil is equal to or less than the reference value, the steady-state operation being an operation in which the gas-phase working medium flows in the order of the first heat exchange unit, the heat exchanger, the second heat exchange unit, the third heat exchange unit, and the heat exchanger.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016-227886 | 2016-11-24 | ||
| JP2016227886A JP6713913B2 (en) | 2016-11-24 | 2016-11-24 | Superconducting magnet device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108109806A true CN108109806A (en) | 2018-06-01 |
| CN108109806B CN108109806B (en) | 2020-03-06 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711200771.5A Expired - Fee Related CN108109806B (en) | 2016-11-24 | 2017-11-24 | Superconducting magnet device |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP6713913B2 (en) |
| KR (1) | KR101984405B1 (en) |
| CN (1) | CN108109806B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113555181A (en) * | 2021-06-15 | 2021-10-26 | 中国科学院合肥物质科学研究院 | Forced flow circulating precooling system for superconducting magnet |
| CN114216291A (en) * | 2021-11-22 | 2022-03-22 | 中国原子能科学研究院 | Normal temperature compressor system and method capable of replacing low temperature circulating pump |
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| JP2015012193A (en) * | 2013-06-28 | 2015-01-19 | 株式会社東芝 | Superconducting magnet device |
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| JP4854953B2 (en) * | 2004-11-11 | 2012-01-18 | 本田技研工業株式会社 | Fuel cell system and low temperature start method of fuel cell system |
| JP2007194258A (en) * | 2006-01-17 | 2007-08-02 | Hitachi Ltd | Superconductive magnet apparatus |
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2016
- 2016-11-24 JP JP2016227886A patent/JP6713913B2/en not_active Expired - Fee Related
-
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- 2017-11-20 KR KR1020170154512A patent/KR101984405B1/en active IP Right Grant
- 2017-11-24 CN CN201711200771.5A patent/CN108109806B/en not_active Expired - Fee Related
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| JPS5549664A (en) * | 1978-10-02 | 1980-04-10 | Hitachi Ltd | Method of controlling cooling of liquefaction refrigerator |
| JPS6453686U (en) * | 1987-09-29 | 1989-04-03 | ||
| JPH01127863U (en) * | 1988-02-25 | 1989-08-31 | ||
| JPH06323663A (en) * | 1993-05-18 | 1994-11-25 | Hitachi Ltd | Refrigerator |
| JP2001027464A (en) * | 1999-07-13 | 2001-01-30 | Mitsubishi Electric Corp | Superconductive electromagnet device |
| JP2015012193A (en) * | 2013-06-28 | 2015-01-19 | 株式会社東芝 | Superconducting magnet device |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113555181A (en) * | 2021-06-15 | 2021-10-26 | 中国科学院合肥物质科学研究院 | Forced flow circulating precooling system for superconducting magnet |
| CN114216291A (en) * | 2021-11-22 | 2022-03-22 | 中国原子能科学研究院 | Normal temperature compressor system and method capable of replacing low temperature circulating pump |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20180058632A (en) | 2018-06-01 |
| JP2018085444A (en) | 2018-05-31 |
| KR101984405B1 (en) | 2019-05-30 |
| JP6713913B2 (en) | 2020-06-24 |
| CN108109806B (en) | 2020-03-06 |
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