WO2005095871A1 - Dispositif de circulation de refrigerant et procede de circulation de refrigerant - Google Patents

Dispositif de circulation de refrigerant et procede de circulation de refrigerant Download PDF

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Publication number
WO2005095871A1
WO2005095871A1 PCT/JP2005/006191 JP2005006191W WO2005095871A1 WO 2005095871 A1 WO2005095871 A1 WO 2005095871A1 JP 2005006191 W JP2005006191 W JP 2005006191W WO 2005095871 A1 WO2005095871 A1 WO 2005095871A1
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WO
WIPO (PCT)
Prior art keywords
refrigerant
storage tank
helium
condenser
dewar
Prior art date
Application number
PCT/JP2005/006191
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English (en)
Japanese (ja)
Inventor
Tsunehiro Takeda
Akira Uchida
Original Assignee
Tsunehiro Takeda
Akira Uchida
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tsunehiro Takeda, Akira Uchida filed Critical Tsunehiro Takeda
Publication of WO2005095871A1 publication Critical patent/WO2005095871A1/fr

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Classifications

    • 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
    • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D19/00—Arrangement or mounting of refrigeration units with respect to devices or objects to be refrigerated, e.g. infrared detectors
    • 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

Definitions

  • the present invention relates to a refrigerant circulating apparatus and a refrigerant circulating method for circulating a refrigerant between a storage tank for storing a refrigerant such as liquid helium at a very low temperature and a condenser connected to a refrigerator.
  • the above-mentioned helium circulating apparatus is composed of a giant MacMahon cycle refrigerator (hereinafter referred to as a "GM refrigerator") capable of cooling helium to about 4K, a condenser connected to the GM refrigerator, and a storage tank.
  • GM refrigerator giant MacMahon cycle refrigerator
  • a purifier that cools and solidifies impurities in the helium gas collected by the heat exchanger to capture the impurities.
  • Low-temperature (approximately 4 to: LOK) helium gas generated in the storage tank is sent to a condenser and re-liquefied into cryogenic liquid helium.
  • Helium gas of relatively high temperature (approximately 300K) generated in the storage tank is collected by a circulation pump and introduced into the purifier, where helium gas power is removed from impurities such as nitrogen and oxygen.
  • the helium gas that has passed through the purifier is gradually cooled by a GM refrigerator and then sent to a condenser where it is re-liquefied into cryogenic liquid helium.
  • Patent Document 1 Japanese Patent Application Laid-Open No. 2000-193364
  • Patent Document 2 U.S. Pat.No. 6,442,948
  • the helium generated in the storage tank as in the above-mentioned conventional helium circulation device is It is not always preferable from the viewpoint of efficiency to re-liquefy the gas into cryogenic liquid helium in a condenser after cooling the gas step by step with a refrigerator.
  • a helium circulation device is required to reduce the piping (refrigerant system) as much as possible to reduce the cost of the entire device.
  • an object of the present invention is to provide a helium circulating apparatus and a helium circulating method that can efficiently re-cool a refrigerant at low cost.
  • the refrigerant circulation device of the present invention includes a storage tank for storing a cryogenic liquid refrigerant, and a condenser connected to the refrigerator and capable of reliquefying the refrigerant.
  • a refrigerant circulation device that circulates refrigerant between a condenser and a refrigerant circulation device that guides a part of the refrigerant gas in a storage tank to a refrigerator and returns the refrigerant gas cooled by the refrigerator to the storage tank.
  • a second system for guiding part of the refrigerant gas in the storage tank to the condenser and returning the refrigerant gas liquefied by the condenser to the storage tank; and a heater provided in the condenser.
  • control means for controlling the heater in accordance with the pressure in the storage tank.
  • the pressure in the storage tank communicating with the condenser via the second system is set to a desired value by adjusting the temperature in the condenser using a heater.
  • the amount of the liquid refrigerant in the storage tank can be maintained at a desired value.
  • the first system deprives the refrigerant gas of the storage tank of heat trying to enter the storage tank. It is preferable to include a region configured to face the refrigerator.
  • the refrigerant circulating apparatus is connected to the first system, and further includes replenishing storage means for storing the replenishing refrigerant, and the replenishing storage means has a part of the first system. It is preferable that the refrigerant can be supplied into the storage tank through the storage tank.
  • the refrigerant circulation device further includes a liquid level detecting means for detecting a liquid level of the liquid refrigerant in the storage tank, and the control means controls the cooling level according to the detection value of the liquid level detecting means. It is preferable that the refrigerant is supplied to the storage tank via a part of the first system.
  • a refrigerant circulation method is a refrigerant circulation method for circulating refrigerant between a storage tank that stores a cryogenic liquid refrigerant and a condenser that has a heater and is connected to a refrigerator.
  • a part of the refrigerant gas in the storage tank is guided to the refrigerator, the refrigerant gas cooled by the refrigerator is returned to the storage tank, and the refrigerant gas is stored while controlling the heater of the condenser according to the pressure in the storage tank. It is characterized in that part of the refrigerant gas in the tank is led to a condenser, and the refrigerant liquefied in the condenser is returned to the storage tank.
  • a part of the refrigerant gas in the storage tank take heat that is going to enter the storage tank so as to face the refrigerator.
  • FIG. 1 is a partial cross-sectional view showing an example of a measurement system including a helium circulation device according to the present invention.
  • FIG. 2 is a sectional view showing a dewar included in the measurement system of FIG. 1.
  • FIG. 3 is a system diagram of a helium circulation device according to the present invention.
  • FIG. 4 is a control block diagram of the helium circulation device shown in FIG. 3.
  • FIG. 5 is a time chart for explaining the operation of the helium circulating device of FIG. 3.
  • FIG. 6 is a flowchart for explaining the operation of the helium circulation device in FIG. 3.
  • FIG. 7 is a time chart for explaining an operation of the helium circulating device of FIG. 3.
  • FIG. 1 is a partial cross-sectional view showing a biomagnetic measurement system which is an example of a measurement system including a helium circulation device according to the present invention.
  • the biomagnetic measurement system 1 is equipped with a superconducting quantum interferometer (hereinafter referred to as “SQUID”) 2 that can non-invasively measure the activity of the brain with high spatiotemporal resolution, and can generate the power of the human brain It can detect a magnetic field.
  • This SQUID2 is contained in a dewar (reservoir) 3 that stores liquid helium of about 4K therein, and is cooled to an operating temperature of about 4K by the liquid helium in the dewar 3.
  • the SQUID 2 and the dewar 3 are arranged in a magnetic shield room SR defined by a nonmagnetic partition wall 4.
  • the dewar 3 is supported by a support member 5 so as to be rotatable around a horizontally extending shaft 6, and a seat (not shown) and a bed (not shown) are provided below the dewar 3. Is arranged.
  • the brain of the subject sitting on the seat or the subject lying on the bed is generated by rotating (tilting) the dewar 3 around the axis 6. Measuring the magnetic field it can.
  • the biomagnetic measurement system 1 collects vaporized helium in a dewar (liquid helium storage tank) 3 by cooling the SQUID 2, which effectively uses rare resources and relatively expensive helium. It has a helium circulation device 20 that liquefies it and returns it to Dewar 3.
  • the helium circulation device 20 has a cold chamber 23 for accommodating a GM refrigerator described below and a container 26 for accommodating various pipes, and is arranged in an accommodation room AR arranged next to the magnetic shield room SR. .
  • a magnetic shielding material is adhered to the inner surface of the partition wall 7 that defines the accommodation room AR in order to suppress the sound and magnetism emitted from the helium circulation device 20 from leaking to the outside.
  • a shaft 8 extending coaxially and horizontally with the axis 6 in the magnetic shield chamber SR is fixed to the support mechanism of the cold chamber 23 and the container 26.
  • the shaft 8 is rotatable by a support block 9. Supported.
  • a rotating knob 11 is connected to the shaft 8 via a speed reducing mechanism 10 such as a worm gear mechanism.By operating the rotating nozzle 11, the cold chamber 23 and the container 26 are rotated around the shaft 8. Can be done. Note that a counterweight W is attached to the lower part of the container 26.
  • the biomagnetism measurement system 1 has a partition 4 that defines the magnetic shield room SR, and a drive shaft 12 that penetrates the partition 7 of the accommodation room AR facing the partition 4.
  • the drive shaft 12 connected to the shaft 8 in the accommodation room AR By rotating the drive shaft 12 connected to the shaft 8 in the accommodation room AR, the cold chamber 23 and the container 26 in the accommodation room AR can be rotated (inclined) from inside the magnetic shield room SR. That is, in the biomagnetic measurement system 1, when the dewar 3 in the magnetically shielded room SR is moved in accordance with the posture of the patient, the cold chamber 23 and the container 26 in the accommodation room AR are moved in accordance with the posture of the dewar 3. Can be done.
  • the dewar 3 and the cold chamber 23 of the helium circulation device 20 are connected to each other via a transfer tube 14.
  • the transfer tube 14 penetrates the elongated hole 4a formed in the partition wall 4 of the magnetic shield room SR and the elongated hole 7a formed in the partition wall 7 of the accommodation room AR.
  • the elongated holes 4a and 7a having an arcuate cross section are formed around the rotation center (shaft 6, shaft 8, etc.) of the duct 13 and the helium circulation device 20.
  • Slots 4a and 7a contain Dewar 3, helium circulator 20 and transfer tube When the movement of the probe 14 is completed, the magnetic shield material 15 is loaded.
  • FIG. 2 is a cross-sectional view showing the dewar 3 included in the biomagnetic measurement system 1.
  • the Dewar 3 has an inner tank 301 and an outer tank 302 surrounding the inner tank 301.
  • SQUID2 and liquid helium as its cooling medium are accommodated in the lower part of the inner tank 301, and inside the inner tank 301, a liquid level gauge 350 for detecting the liquid level of the liquid helium is arranged.
  • the outer tub 302 is formed of a heat insulating material such as FRP, and the upper end of the outer tub 302 is closed by a closing member 303.
  • a heat insulating space 304 is defined between the inner tank 301 and the outer tank 302. Vacuum suction is applied to the heat insulating space 304, whereby a vacuum layer is formed between the inner tank 301 and the outer tank 302.
  • An upper insert 305 which is formed in a hollow and substantially cylindrical shape, is disposed in an upper portion of the inner tank 301. Inside the upper insert 305, a first vacuum chamber 306 that is maintained in a vacuum state is defined. An annular space 307 is defined between the outer wall surface of the upper insert 305 and the inner wall surface of the inner tank 301. Further, inside the inner tank 301, the lower insert 308 is disposed so as to be located between the lower surface of the upper insert 305 and the liquid surface of the liquid helium. The lower insert 308 is also formed in a hollow and substantially cylindrical shape, and defines therein a second vacuum chamber 309 maintained in a vacuum state.
  • a space 310 communicating with the above-described space 307 is defined between the lower surface of the upper insert 305 and the upper surface of the lower insert 308, and the outer wall surface of the lower insert 308 is formed.
  • An annular space 311 communicating with the spaces 307 and 310 is defined between the inner space 301 and the inner wall surface of the inner tank 301.
  • a space 312 communicating with the space 311 is defined between the lower surface of the lower insert 308 and the liquid level of the liquid helium.
  • the lower surface of the lower insert 308 is formed in the shape of a conical surface inclined upward from the outer periphery toward the center.
  • a heat transfer member 314 is provided via a heat shield member 313 also made of copper or the like. Installed.
  • a plurality of locations on the outer wall surface of the first vacuum chamber 306 (in this embodiment, In three places, a heat shield member 315 having a strength such as a copper material is also attached.
  • the upper two heat shield members 315 are arranged so as to correspond to the respective heat shield members 313 in the upper insert 305, and the lower one heat shield member 315 is connected to the upper insert 305. It is arranged so as to surround a space 310 between the lower insert 308 and the lower insert 308.
  • each heat shield member 315 a plurality (three in this example) of heat transfer members 316, 317, 318 formed so as to surround the inner tank 301 are fixed, and each heat transfer member 316 is fixed. To 318 are located in the above-described heat insulating space 304.
  • the outer two heat transfer members 316 and 317 are formed in a substantially cylindrical shape, and their free ends reach near the lower end of the inner tank 301. I have.
  • the innermost heat transfer member 318 is formed in a bottomed cylindrical shape, and covers substantially a lower half of the inner tank 301.
  • the upper end of the above-mentioned upper insert 305 (the end on the side of the closing member 303) is reduced in diameter, so that around the upper end of the upper insert 305, A space 319 communicating with the space 307 is defined.
  • the first recovery pipe L10 is connected to the closing member 303 so as to communicate with the space 319.
  • the distal end of the transfer tube 14 is inserted through the center hole of the upper insert 305 and the lower insert 308.
  • the transfer tube 14 is configured as a multiple tube by concentrically integrating the cooling pipe Lll, the second recovery pipe L20, and the return pipe L21 in order from the outside.
  • the cooling pipe L11 constituting the transfer tube 14 is open in a space 310 between the upper insert 305 and the lower insert 308, as shown in FIG.
  • the second recovery pipe L20 and the return pipe L21 constituting the transfer tube 14 are open in a space 312 between the lower insert 308 and the liquid surface of the liquid helium.
  • a gap 320 communicating the space 310 and the space 312 is defined between the outer peripheral surface of the second suction pipe L20 and the inner peripheral surface of the center hole of the lower insert 308.
  • FIG. 3 is a system diagram of the helium circulating device 20 included in the biomagnetic measurement system 1.
  • the helium circulating device 20 is connected to the above-described Dewar 3, the first recovery pipe L10, the cooling pipe Lll, the second recovery pipe L20, and the return pipe L21, and is provided with two circulation pumps 21, GM refrigerator 22, purifier 30 and condenser 40 and GM refrigerator 22, refiner 30 and condenser And a cold chamber 23 for accommodating the container 40.
  • Each GM refrigerator 22 has a first refrigeration unit 22a for cooling helium gas to approximately 40K and a second refrigeration unit 22b for cooling helium gas to approximately 4K.
  • the first recovery pipe L10 extending from the upper part of the dewar 3 has a valve VI, a mass flow meter MF1, and a solenoid valve EV1 (normally open) in the middle, and the distal end thereof is connected to the suction port of the circulation pump 21. ing.
  • One end of a gas pipe L12 is connected to a discharge port of the circulation pump 21.
  • the gas pipe L12 together with the first recovery pipe L10 and the cooling pipe L11, guides a part of the helium gas in the duct 13 to the GM refrigerator 22, and also converts the helium gas cooled by the GM refrigerator 22 to the dewar 3. Configure the first system for returning.
  • Gas pipe L12 has filters F1 and F2, constant flow control valve MFC, flow meter FM and solenoid valve EV2 (normally closed) in the middle, and the other end of gas pipe L12 is a purifier in cold chamber 23. Connected to 30 fluid inlets!
  • the purifier 30 cools and solidifies impurities in the helium gas recovered from the Dewar 3, and captures the impurities.
  • the purifier 30 allows the helium gas to flow therethrough, and sufficiently mixes the helium gas with the helium gas.
  • a porous capture means configured to be in contact therewith, the capture means being located on the outlet side of the body and being connected to a cold heat source.
  • One end of the cooling pipe L11 is connected to a fluid outlet of the purifier 30 via a check valve 50.
  • the cooling pipe L11 has a heat transfer pipe HP arranged in the first refrigeration section 22a of the one GM refrigerator 22.
  • the condenser 40 is connected to the second refrigeration units 22b of the two GM refrigerators 22, and the inside temperature of the condenser 40 is maintained at about 4K by each of the second refrigeration units 22b. Further, the condenser 40 is provided with a heater 41 for adjusting the internal temperature.
  • the condenser 40 is connected to the second recovery pipe L20 and the return pipe L21. The second recovery pipe L20 and the return pipe L21 guide a part of the helium gas in the dewar 3 to the condenser 40, and a second system for returning the helium that has been filtered in the condenser 40 to the dewar 3. Constitute.
  • a helium discharge pipe having a solenoid valve EV3 in the middle is connected to the first recovery pipe L10.
  • An exhaust pump (suction means) 24 is connected between the flow meter FM of the gas pipe L12 and the valve V2 via a solenoid valve EV4, a mass flow meter MF4, a valve V4, and a vacuum port. Exhaust pump 24 is used to remove impurities from purifier 30 Is done.
  • a helium cylinder 25 is connected between the circulation pump 21 of the gas pipe LI2 and the filter F1 via a solenoid valve EV5, a mass flow meter MF5, a filter F5, and a valve V5.
  • Helium cylinder 25 stores helium gas at normal temperature (300K).
  • the helium circulation device 20 has pressure sensors Pa and Pb.
  • the pressure sensor Pa detects the internal pressure of the Dewar 3 (pressure of helium gas).
  • the pressure sensor Pb detects the pressure of the helium gas at the inlet of the purifier 30.
  • These pressure sensors Pa and Pb are connected to a control unit 100 functioning as a control means of the helium circulation device 20, as shown in FIG.
  • the control unit 100 is connected to the mass flow meters MF1, MF4, and MF5, the flow meter FM, valves such as the solenoid valves EV1 to EV5, the circulation pump 21, the exhaust pump 24, and the like.
  • control unit 100 is also connected with a liquid level gauge 350 of the Dewar 3, a heater 41 of the condenser 40, and the like.
  • the control unit 100 controls the circulation pump 21, the exhaust pump 24, various valves, and the like based on the detection values of various sensors.
  • the above-mentioned valves VI, V2 and V4, V5 are manual valves for use during assembly and maintenance, and are open during operation.
  • the solenoid valves EV1 to EV5 used for control are such that the solenoid valve EV1 is normally open, and the other valves are normally closed.
  • the liquid helium is cooled in the dewar 3 by cooling the SQUID 2 and the like. Evaporate not a little. Then, a part of the helium gas of about 4K vaporized near the liquid surface of the liquid helium flows to the center along the lower surface of the lower insert 308, and the second recovery opening in the space 312 It flows into condenser 40 via line L20.
  • the helium gas of about 4K flowing into the condenser 40 is liquefied in the condenser 40 maintained at about 4K by the second refrigeration unit 22b of each GM refrigerator 22, and the return pipe L21 It is returned to the lower part of the inner tank 301 of the Dewar 3 via.
  • the heat that has entered the inside of the outer tank 302 is transmitted to each of the heat transfer members 316 to 318, the heat is transferred from the heat transfer material 316 to 318 Introduced to Noredo 315 , Accumulate there.
  • the heat transmitted to the upper insert 305 via the transfer tube 14 or the like is transmitted to the heat shield member 313 via the heat transfer member 314 and is accumulated there.
  • the helium gas in the Dewar 3 flows from the periphery of the space 310 to the space 319 above the inner tank 301 via the space 307 around the upper insert 305, the helium gas is Then, the heat stored in each of the heat shield members 313 and 315 is removed, and the temperature is increased to, for example, about 300K.
  • the helium gas in the dewar 3 As described above, of the helium gas in the dewar 3, the helium gas that has been heated to some extent by removing heat from the surroundings is sucked into the first recovery pipe L10 by the circulation pump 21, and the one GM refrigerator
  • the heat transfer tube HP is disposed in the first freezing section 22a of the heat transfer tube 22 and is led to the heat transfer tube HP.
  • the helium gas is cooled to about 40K in the first freezing section 22a, and is returned to the space 310 between the upper insert 305 and the lower insert 308 via the cooling pipe L11.
  • the helium gas of about 40K returned to the space 310 circulates in the first system including the first recovery pipe L10 and the like.
  • the heater 41 of the condenser 40 is controlled by the control unit 100 according to the procedure shown in FIG. That is, while the helium circulation device 20 is operating, the control unit 100 monitors the detection value of the pressure sensor Pa that detects the internal pressure P of the dewar 3, and the helium liquefaction in the condenser 40 proceeds. When the internal pressure P of the dewar 3 drops and the internal pressure P of the dewar 3 detected by the pressure sensor Pa becomes the lower limit value P, the heater 41 of the condenser 40 is turned on.
  • the control unit 100 monitors the detection value of the pressure sensor Pa even after the heater 41 is turned on, and after the heater 41 is turned on, the internal pressure P of the dewar 3 is increased. Reaches the upper limit value P, the heater 41 of the condenser 40 is turned off.
  • a partial force of the helium gas in the dewar 3 is used to radiate the heat that tries to enter the inner tank 301 in the space 307 and the like included in the first system described above. It will be directed to the first refrigeration section 22a of the GM refrigerator 22 and vaporized inside the Dewar 3.
  • the helium gas discharges the heat to the outside of the dewar 3, so that the vaporization of the helium in the dewar 3 and the further increase in the temperature of the helium gas in the dewar 3 are surely suppressed.
  • the temperature in the condenser 40 is adjusted by ONZOFF control of the heater 41, so that the helium circulation device 20 communicates with the condenser 40 through the second recovery pipe L20 and the return pipe L21 (second system).
  • the internal pressure P of the communicating Dewar 3 is adjusted to a desired value, the amount of liquid helium in the Dewar 3 can be maintained at a desired value.
  • the vaporization of helium in the dewar 3 and the further increase in the temperature of the helium gas in the dewar 3 can be reliably suppressed.
  • the second system second recovery pipe L20 and return pipe L21
  • Simply circulating the helium through may deplete the liquid helium in the Dewar 3.
  • the helium gas is stored in the gas pipe L12 constituting the first system together with the first recovery pipe L10 and the cooling pipe L11 as described above. Cylinder 25 is connected. As a result, helium gas can be supplied from the helium cylinder 25 into the dewar 3 through the gas pipe L12 and the cooling pipe L11, which are part of the first system. The replenishment of helium can be performed without installing a system.
  • Such a helium replenishment process for the dewar 3 is performed according to the procedures shown in Figs. 6 and 7. That is, during the operation of the helium circulation device 20, the control unit 100, as shown in FIG. 6, controls the liquid helium in the dewar 3 based on the detection value of the liquid level gauge 350. (S10), and the acquired liquid level L is set to a predetermined lower limit L.
  • control unit 100 determines in S12 that the liquid level L of the liquid helium in the dewar 3 is equal to or less than the predetermined lower limit L. , Again, 350
  • the liquid level L of the liquid helium in the dewar 3 is acquired based on the detected value (S14), and it is determined whether the acquired liquid level L is lower than a predetermined value L (S16). value
  • L is a value sufficiently larger than the lower limit L, and if the liquid level is equal to or higher than the value L,
  • liquid level L is lower than predetermined value L in S16.
  • the pressure at which 1 is turned on (lower limit value) P is larger than the pressure at which the heater 41 is turned off (upper limit value).
  • the control unit 100 is in the dewar 3
  • control unit 100 determines in S20 that the internal pressure P of the dewar 3 is equal to or less than the value P.
  • the solenoid valve EV5 and the like are opened, and the supply (replenishment) of the helium gas from the helium cylinder 25 to the dewar 3 is started (S22).
  • the helium gas from the helium cylinder 25 is cooled to about 40K via the gas pipe L12 and the cooling pipe L11 and then supplied to the duct 13.
  • the control unit 100 acquires the internal pressure P of the Dewar 3 based on the detection value of the pressure sensor Pa (S24), and the acquired internal pressure P of the Dewar 3 is set to a predetermined value P
  • the above-described force / non-force determination is made (S26). Where the value P
  • the value P may be set so as to satisfy P ⁇ P ⁇ P.
  • the control unit 100 determines in S26 that the internal pressure P of the dewar 3 is equal to or higher than the value P.
  • the solenoid valves EV5 etc. are closed, and helium gas is transferred from the helium cylinder 25 to the dewar 3.
  • the supply (replenishment) is stopped (S28).
  • the control unit 100 After the processing in S28, the control unit 100 returns to S14, acquires the liquid level L of the liquid helium in the dewar 3, and determines whether or not the acquired liquid level L is lower than the predetermined value L. Is determined (S16). At this stage, the Dewar 3
  • control unit 100 If the liquid helium level is below L, the control unit 100
  • liquid helium is not sufficiently replenished in 3 and the above-described processing of S18 to S28 is repeated. Also, at this stage, the liquid level of the liquid helium in Dewar 3 becomes L or more.
  • control unit 100 assumes that there is a sufficient amount of liquid helium in the dewar 3, and performs the liquid level monitoring of the liquid helium in the dewar 3 in S10 and S12.
  • the internal pressure P of the dewar 3 is set to a value P larger than the pressure (upper limit value) P.
  • the helium tank 25 starts replenishing helium gas to the dewar 3 (S22). Thereafter, as shown in FIG. 7, the internal pressure of the dewar 3 rises, and the helium gas is discharged.
  • the heater 41 of the condenser 40 will not be turned on during replenishment. Therefore, even if the helium gas is supplied (supplemented) directly into the dewar 3 without causing the helium gas to flow outside the dewar 3, the helium gas is surely fed into the dewar 3 or the condenser 40. I do. Further, if the internal pressure P of the Du-3 becomes more than the value P, the replenishment of helium gas is stopped (S28).
  • the liquid level control procedure in the dewar 3 is not limited to the one illustrated in FIG. 5, and the helium replenishment procedure in the dewar 3 is as illustrated in FIG. It is needless to say that other procedures can be adopted as these liquid level control procedures and helium replenishment procedures. And this invention can be implemented in any other form, without deviating from the idea and main characteristic power. Therefore, the above-described embodiment is merely an example in all respects, and should not be construed as limiting.

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Abstract

Il est prévu un dispositif de circulation d’hélium capable de reliquéfier un réfrigérant de manière efficace à bas prix ; et un procédé de circulation d’hélium. Un dispositif de circulation d'hélium (20) comprend un Dewar (3) stockant de l’hélium liquéfié à environ 4 K, un condenseur (40) connecté à un congélateur GM (22) et servant à reliquéfier du gaz hélium, un premier système contenant un premier tube de récupération (L10), un tube de refroidissement (L11) et un tube de gaz (L12) pour entraîner une partie du gaz hélium dans le Dewar (3) dans le congélateur (22) et retourner le gaz hélium refroidi par le congélateur GM (22) dans le Dewar (3), un second système contenant un second tube de récupération (L20) et un tube de retour (L21) pour entraîner une partie du gaz hélium dans le Dewar (3) dans le condenseur (40) et retourner le gaz hélium liquéfié par le condenseur (40) dans le Dewar (3), un radiateur (41) installé dans le condenseur (40), et une unité de commande (100) pour réguler le radiateur (41) selon la pression du dispositif dans le Dewar (3).
PCT/JP2005/006191 2004-03-31 2005-03-30 Dispositif de circulation de refrigerant et procede de circulation de refrigerant WO2005095871A1 (fr)

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JP2004107891A JP4565226B2 (ja) 2004-03-31 2004-03-31 冷媒循環装置および冷媒循環方法
JP2004-107891 2004-03-31

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FR2989156A1 (fr) * 2012-04-04 2013-10-11 Air Liquide Dispositif de stockage de produits a des temperatures cryogeniques
CN115388615A (zh) * 2022-04-19 2022-11-25 北京师范大学 一种氩液化系统

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Publication number Priority date Publication date Assignee Title
JP4908439B2 (ja) * 2008-02-28 2012-04-04 住友重機械工業株式会社 冷却システム及び脳磁計
KR101632280B1 (ko) 2014-09-05 2016-07-01 한국표준과학연구원 냉각기 냉각형 스퀴드 측정 장치
KR101632293B1 (ko) * 2014-09-12 2016-06-21 한국표준과학연구원 냉각기 냉각형 초전도양자간섭소자 시스템 및 냉각기 냉각형 초전도양자간섭소자 시스템의 동작 방법
KR101606756B1 (ko) * 2014-09-12 2016-04-11 한국표준과학연구원 냉각기 냉각형 초전도양자간섭소자 시스템 및 냉각기 냉각형 초전도양자간섭소자 측정 방법
JP6619958B2 (ja) * 2015-06-25 2019-12-11 株式会社 フジヒラ 微弱磁気計測装置の冷却システム

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JP2004028516A (ja) * 2002-06-28 2004-01-29 Sanyo Electric Co Ltd 保存装置

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CN115388615B (zh) * 2022-04-19 2023-11-24 北京师范大学 一种氩液化系统

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