WO2001035034A1 - Dispositif de refroidissement cryogenique - Google Patents

Dispositif de refroidissement cryogenique Download PDF

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Publication number
WO2001035034A1
WO2001035034A1 PCT/EP2000/011143 EP0011143W WO0135034A1 WO 2001035034 A1 WO2001035034 A1 WO 2001035034A1 EP 0011143 W EP0011143 W EP 0011143W WO 0135034 A1 WO0135034 A1 WO 0135034A1
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WO
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Prior art keywords
temperature
cooling device
pulse tube
cooling
low
Prior art date
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PCT/EP2000/011143
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German (de)
English (en)
Inventor
Jens HÖHNE
Original Assignee
Csp Cryogenic Spectrometers Gmbh
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Application filed by Csp Cryogenic Spectrometers Gmbh filed Critical Csp Cryogenic Spectrometers Gmbh
Priority to AU23556/01A priority Critical patent/AU2355601A/en
Publication of WO2001035034A1 publication Critical patent/WO2001035034A1/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
    • 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
    • F25B9/145—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 pulse-tube cycle
    • 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
    • F25B2309/00—Gas cycle refrigeration machines
    • F25B2309/14—Compression machines, plants or systems characterised by the cycle used 
    • F25B2309/1408—Pulse-tube cycles with pulse tube having U-turn or L-turn type geometrical arrangements
    • 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
    • F25B9/10—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point with several cooling stages
    • 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
    • F25D19/006—Thermal coupling structure or interface

Definitions

  • the invention relates to a low-temperature cooling device according to claims 1 and 2.
  • cooling devices have a wide range of uses due to the use of one or more pulse tube coolers and are preferably used as mobile cooling devices which allow cooling to low or very low temperatures at any location.
  • a cooling device according to the invention is therefore suitable, for example, for cooling components made of high-temperature superconductors, such as SQUIDs, for cooling semiconductor components, such as infrared detectors or high-speed circuits for very fast data processing, or also for cooling sensors based on a low-temperature effect.
  • a device for cooling a superconducting magnet system housed in a cryostat which uses a two-stage pulse tube cooler system, as shown in FIG. 1.
  • a first pulse tube 20 has at its lower end a first cold head 24, which is connected on the one hand to a first regenerator and on the other hand to the magnet system 82 to be cooled.
  • a second pulse tube 30 has a second cold head 34, which is connected to a radiation shield 81 which surrounds the lower section of the first pulse tube 20 or the first cold head 24 and the magnet system 82, but is thermally insulated from the first pulse tube 20.
  • the pulse tube cooler system If the pulse tube cooler system is put into operation, heat or thermal energy is absorbed and dissipated at the first 24 and second 34 cold heads.
  • This cooling process which takes place approximately at room temperature, i.e. about 300 K, is shown schematically in Figure 2.
  • the second pulse tube 30 If the second pulse tube 30 is put into operation at the time tO, since its cooling capacity is optimized for higher temperatures, it reaches its target temperature of approximately 60 K on the second cold head 34 after a relatively short time t1, as shown by line 230.
  • the first pulse tube 20 since its cooling capacity is optimized for lower temperatures, the first pulse tube 20 only reaches a temperature of approximately 60 K at the first cold head 24 later by ⁇ t t2, as shown in line 220, and then after further cooling at time t3 to have a temperature of approximately 4K.
  • the cooling process on the first pulse tube especially in an initial cooling phase, in which relatively high temperatures are still present, takes a very long time.
  • the low-temperature cooling device according to a first aspect comprises: a first cooling device in the form of a first pulse tube cooler with a first pulse tube, which has a first cold head for providing a first cooling area with a first temperature TE, and with a first regenerator, which has a first cold end section , which is connected to the first cold head of the first pulse tube; and a second cooling device with a second cooling area for providing a second temperature TZ1, which is higher than the first temperature TE.
  • the second cooling area can be thermally coupled to the first pulse tube and / or the first regenerator via a first heat switch.
  • the second cooling area is connected to the Most pulse tube and / or the first regenerator and / or the object to be cooled can be thermally coupled.
  • the measure according to the invention makes it possible, in particular at the beginning of a "cold run" or a cooling process of the low-temperature cooling device, i.e. if the temperature of the cooling devices or the object to be cooled is still at a relatively high temperature, such as the room temperature, the second cooling area of the second cooling device via a first heat switch with the first pulse tube and / or the first regenerator and / or (in the case of the second aspect) to thermally couple the object to be cooled.
  • the cooling capacity of the second cooling device which is better or optimized for higher temperatures, can (additionally) be used in a relatively short time to also the first pulse tube cooler, the cooling capacity of which is more optimized for lower or lower temperatures Time to cool down to the temperature TZ1, which the second cooling area provides. If after a certain time the second cooling area and the corresponding components of the first pulse tube cooler or the object to be cooled, which are thermally coupled to it, are at the target temperature TZ1 of the second cooling area, the first heat switch is opened or brought into a non-heat-conducting state , and the first pulse tube cools down further to its first temperature or setpoint temperature TE at the first cold head. Thus, the cooling process of the low-temperature cooling device or the object to be cooled is accelerated.
  • the second cooling area can be thermally coupled via the first heat switch to the first cold head of the first pulse tube and / or the first cold end section of the first regenerator.
  • the coupling with the first cold head or the The first cold end section does not have to be directly at this, but can also take place in the vicinity thereof.
  • the low-temperature cooling device can furthermore have a third cooling device with a third cooling area for providing a third temperature TZ2, which is higher than the second temperature TZ1, the third cooling area having a second heat switch with the second cooling device, preferably on the second cooling device second cooling area, is thermally coupled.
  • a third cooling device with a third cooling area for providing a third temperature TZ2, which is higher than the second temperature TZ1, the third cooling area having a second heat switch with the second cooling device, preferably on the second cooling device second cooling area, is thermally coupled.
  • This measure allows a direct thermal connection from the third to the second cooling device or from there to the first pulse tube cooler. It is conceivable that the third cooling area can also be thermally coupled to the first pulse tube and / or the first regenerator and / or the object to be cooled via a third heat switch.
  • the low-temperature cooling device can also have a third cooling device with a third cooling area for providing a third temperature TZ2, which is higher than the second temperature TZ1, here the third cooling area using a third heat switch with the first pulse tube and / or the first regenerator and / or the object to be cooled can be thermally coupled.
  • This measure allows a direct thermal connection from the third to the first cooling device or the first pulse tube cooler.
  • the third cooling area can be thermally coupled to the first cold head of the first pulse tube and / or the first cold end section of the first regenerator via the third heat switch.
  • the coupling with the first cold head or the The first cold end section does not have to be directly at this one, but can also take place in the vicinity thereof.
  • a third cooling device permits a further staggering of the cooling devices in accordance with their cooling capacities optimized for certain temperatures or temperature ranges. This means that when the low-temperature cooling device is driven cold, starting from a temperature, such as room temperature, in a first cooling phase, the third cooling device can advantageously be thermally coupled to the first and second cooling devices in order to achieve better or optimized cooling performance for higher temperatures to use the third cooling device for rapid cooling down of the three cooling devices or the components connected to them.
  • the target temperature TZ2 of the third cooling device has been reached, the second or third heat switch is opened in order to allow the second and first cooling device to cool down further.
  • the second cooling device in particular the second cooling area, is thermally connected via the first heat switch to the first pulse tube cooler or the object to be cooled, in order to avoid the "medium" temperatures, ie temperatures below TZ2 to TZl to use better or optimized cooling performance of the second cooling device.
  • the better cooling performance of the second cooling device is used for rapid cooling down of the second and first cooling devices or the components connected to them. If the target temperature TZl of the second cooling device has been reached, the first heat switch is opened in order to allow the first cooling device or the object to be cooled to cool further to the target temperature TE in a third cooling phase.
  • thermo coupling via heat switch can be carried out analogously to the diagram shown above, in order to achieve a gradual cooling down of the entire low-temperature cooling device.
  • the better cooling performance of higher-level cooling devices at higher temperatures can then be used again in order to bring about rapid cooling.
  • the second cooling device has a second pulse tube cooler, on the pulse tube of which a second cold head is provided for providing the second cooling area with the temperature TZl. If, according to one of the above advantageous embodiments, a second heat switch is provided for interruptible thermal coupling of the third cooling area to the second cooling device, this coupling can be carried out on the entire second cooling device, i.e. the second pulse tube or the second regenerator, but in particular on or in the vicinity of the second cold head or on or in the vicinity of the second cold end section of the second regenerator.
  • the third cooling device can have a third pulse tube cooler, on the pulse tube of which a third cold head is provided for providing the third cooling area with the temperature TZ2. In a broader sense, as with the first or second pulse tube cooler, not only the respective cold head, but also the cold end section of the respective regenerator that is directly connected to the cold head, can be regarded as a cooling area.
  • the second cooling device and / or third cooling device has an electrical cooling device, such as a pelletizing element, in order to provide a second or third cooling area. It is also conceivable that the second and / or third cooling device has a cooling device based on cooled liquefied gases, such as a nitrogen cooler, or a mechanical cooling device such as a helium compression cooler.
  • the first, second and third heat switches are designed as a mechanical heat switch, as a gas heat switch or as a superconducting heat switch (cf. Frank Pobell: “Matter and methods at low temperatures", 2nd edition, Springer- Verlag 1996).
  • Mechanical heat switches are based on the principle that thermal, highly conductive input or output contact materials, such as metals (e.g. copper, brass, gold), are mechanically pressed together when pressure is applied. This creates a contact between the materials, so that a heat flow can flow in this closed state of the heat switch.
  • the thermal conductivity of this mechanical heat switch can be varied by changing the contact pressure. It is found to be particularly advantageous in the mechanical heat switch that when the contact materials are detached from one another, i.e. when there is no longer any mechanical contact between the contact materials, the heat switch is really open in this open state and does not allow any heat flow to flow through it.
  • the gas heat switch is based on the principle that a gas (for example hydrogen, nitrogen, etc.) is provided for the thermal coupling between two or more coupling parts, ie in the closed state of the heat switch is.
  • a gas for example hydrogen, nitrogen, etc.
  • the gas In order to open the gas heat switch, the gas is either removed by pumping, or it is frozen out or converted into a liquid state by the action of cold in order to prevent heat transfer between the coupling parts.
  • a coupling material such as, for example, a certain metal (for example Al, Pb, Zn, Sn, In), which is between a superconducting state and a normally conductive state " is switchable ".
  • a coupling material such as, for example, a certain metal (for example Al, Pb, Zn, Sn, In)
  • This switching can be achieved in that the coupling material in the superconducting state is brought into the normal conducting state, for example by applying a magnetic field with a strength above the critical field strength. If the coupling material is in the normally conductive state, it has a high thermal conductivity, while in the superconducting state it has a thermal conductivity that is several orders of magnitude lower.
  • the object to be cooled by the cooling device according to the invention has, for example, a reservoir of a liquefied gas, such as a helium reservoir.
  • the object to be cooled can have a magnet based on a superconducting or normally conducting material, which can serve as part of a demagnetization stage (as a special low-temperature cooling device suitable for very low temperatures in the vicinity of the absolute zero point).
  • the object to be cooled can also have a sensor for detecting particles, radiation or fields.
  • sensors can sensors with an operating temperature in the range of about 30 to 100 K, such as silicon detectors (Si (Li) detectors), germanium detectors (HPGe detectors) or on high-temperature superconductors.
  • the object to be cooled can also have sensors that are based on a low-temperature effect, these sensors being due to their operating temperature less than 20 K, usually even less than 4 K, from a low-temperature cooling device (for example an adiabatic demagnetization stage or a 3He / 4He demixing cooling stage), which is connected to the first cold head of the first pulse tube, are cooled to the corresponding operating temperature.
  • a low-temperature cooling device for example an adiabatic demagnetization stage or a 3He / 4He demixing cooling stage
  • the sensors used in the detector device based on a low-temperature effect are sensors which measure energy deposited by radiation or particle absorption by means of an effect which only or in particular occurs at low temperatures. These temperatures are provided by a heat sink which is thermally coupled to the detector device, which has a respective sensor based on a low-temperature effect.
  • Superconductivity is a low-temperature effect. The lower the transition temperature to superconductivity, the more of these quasiparticles are generated by the energy deposition. The more quasi part the more energy can be determined.
  • thermometers such as a sensor in a microcalorimeter: These essentially consist of an absorber, a phase transition thermometer (superconducting layer, e.g. made of tungsten, iridium, aluminum or tantalum) and a cooling device or a coupling to a heat sink. In the temperature transition area between its superconducting and normal conducting phase, the thermometer changes its electrical resistance very strongly depending on the temperature, i.e. even after absorption of lattice vibrations and quasiparticles.
  • Superconducting tunnel diodes They consist of two overlapping thin superconducting films (SIS: superconductor-insulator-superconductor, whereby the films do not necessarily have to consist of the same superconductor on both sides) or a superconducting and a normally conducting film (NISt normal conductor- Insulator super conductor), the respective films being separated by a thin electrically insulating barrier. The barrier is so thin that they quantified echanical tunneling M
  • the NIS diode or SIS diode is operated below the transition temperature of the respective superconductor and the applied voltage is less than the voltage (NIS) corresponding to the superconducting energy gap or less than twice this voltage (SIS), the voltage rises the barrier current flows when energy is deposited in the tunnel diode.
  • the deposition of the energy can take place through an increase in temperature, absorption of lattice vibrations or quasiparticles or directly through absorption of radiation or particles.
  • NTD NTD thermometer
  • NTD Neurotron Transmutation Doping
  • semiconductors highly doped with neutrons These thermometers can be used to measure temperature fluctuations because, like all semiconductors, the resistance increases with decreasing temperature. In order to avoid that the resistors grow so high at very low temperatures that they can no longer be measured with sufficient accuracy, the semiconductors used are heavily doped, as a result of which their resistance is reduced.
  • Magnetic bolometers These sensors, which have a weak thermal coupling to a cold bath or a heat sink with a temperature preferably in the millivin range, comprise a weak concentration of paramagnetic ions in a magnetic field.
  • rare earth ions such as erbium (Er3 +) are advantageously used. If a small amount of energy, for example due to electromagnetic radiation, is deposited in such a sensor, the rise in temperature causes a change in the magnetization of the paramagnet formed by the paramagnetic ions, for example using a coil connected to an input of a sensor SQUIDs is connected, can be measured.
  • An absorber is advantageously thermally coupled to the magnetic bolometer.
  • the object to be cooled can also have a large number of sensors. This is advantageous, for example, if two different types of sensors are used, the energy resolution of which is different in each case in different energy ranges.
  • Figure 1 is a schematic sectional view from the side of a two-stage pulse tube cooler device in the prior art
  • FIG. 2 shows a diagram to illustrate the time course of the cooling process on the first cold head of the first pulse tube and on the second cold head of the second cold head of the pulse tube cooler device shown in FIG. 1;
  • Figure 3 is a schematic sectional view from the side of a cryogenic cooling device according to the invention according to a first embodiment
  • Figure 4 is a schematic sectional view from the side of a cryogenic cooling device according to the invention according to a second embodiment
  • FIG. 5 each show diagrams to illustrate the time course of the cooling process on the first cold head of a first pulse tube and on the second cold head of a second cold head of a pulse tube cooler device or low-temperature cooling device, FIG. 5a showing the cooling course in a conventional cooling device and FIG. 5b showing the cooling course in one shows cooling device according to Figures 3 or 4;
  • Figure 6 is a schematic sectional view from the side of a cooling device according to the invention according to a third embodiment
  • Figure 7 is a schematic representation of a pulse tube cooler according to a first embodiment
  • Figure 8 is a schematic representation of a pulse tube cooler according to a second embodiment
  • Figure 9 is a schematic representation of a pulse tube cooler according to a third embodiment.
  • Figure 10 is a schematic representation of a pulse tube cooler according to the third embodiment in a more concrete representation than in Figure 9;
  • Figure 11 is a schematic representation of a two-stage pulse tube cooler system with the most important components.
  • FIG. 3 shows a schematic representation of a first embodiment of a deep-temperature cooling device according to the invention.
  • the same parts are denoted by the same reference numerals.
  • the low-temperature cooling device according to the invention is here, as well as in the following embodiments, advantageously arranged to improve the cooling performance in a cooling container or a cryostat, the temperature levels (300K, 77K) shown in the figures representing areas which are advantageously affected by heat or Radiation shields for heat insulation are surrounded.
  • a warm head 22 (located at the upper end of a pulse tube 20 and not explicitly identified) of a first pulse tube 20, a warm head 32 (located at the upper end of a pulse tube 30 and not explicitly identified) of a second pulse tube 30, and a warm end portion 54 of a second regenerator 50 in thermal contact with the 300 K temperature level, for example a cryostat cover that is in contact with the environment.
  • the two regenerators 40 and 50 of the pulse tubes 20 and 30 are connected to one another, so that the upper regenerator 50 is used by the regenerator 40 as a warm regenerator section 50 or for coupling to the 300 K temperature level.
  • an arrangement with two separate regenerators is conceivable. bar.
  • the first and second pulse tubes 20 and 30, as well as the regenerators or regenerator sections 40 and 50 are arranged essentially parallel and in the direction of gravity.
  • a cold head 24 is provided at the lower end of the first pulse tube 20, at which a cooling temperature of approximately 4 K (TE) is provided on an object to be cooled, here on a magnet 82.
  • TE cooling temperature
  • a cold head 34 is provided, at which a cooling temperature of approximately 77 K (TZ) is provided for precooling the first pulse tube 20. More specifically, the temperature of 77 K is provided to a cooling area containing the cold head 24 of the first pulse tube and the magnet 82, which in the case of using a cryostat is surrounded by a heat shield 81 for thermal insulation.
  • the cold head 24 of the first pulse tube 20 is connected to a cold end section 46 of the regenerator 40 via a line 42 and the cold head 34 of the second pulse tube 30 is connected to a cold end section 56 of the second regenerator 50 via a line 52.
  • the lines 42, 52 are gas lines which are provided for transferring the oscillating gas from the respective regenerators 40, 50 to the pulse tubes 20, 30.
  • the cold head 34 of the second pulse tube 30 is thermally coupled (interruptible) to the cold head 24 of the first pulse tube 20 via a heat switch 100, which is preferably designed here as a mechanical heat switch.
  • the coupling of the heat switch 100 to the respective components 34 and 24 takes place via lines 101, 101 ', which are preferably wire or tubular lines made of a thermally highly conductive (eg copper, gold) material.
  • lines 101, 101 ' are preferably wire or tubular lines made of a thermally highly conductive (eg copper, gold) material.
  • thermally highly conductive eg copper, gold
  • temperature levels indicated in this, as well as in the other embodiments, serve for illustration and may have different values depending on the prevailing operating state or the operating mode or depending on the ambient temperature.
  • FIG. 4 shows a schematic illustration of a second embodiment of the low-temperature cooling device according to the invention.
  • the structure of the low-temperature cooling device according to the second embodiment essentially corresponds to that of the first embodiment, which is why reference is made to the detailed description thereof at this point.
  • the second cold head 34 is coupled via the heat switch 100 or the lines 101, 101 'to the first pulse tube cooler 20, 40 by thermal coupling to the cold end section 46 of the regenerator 40. Whether to the cold end section 46 (second Embodiment) or the cold head 24 (first embodiment) is dependent on what is technically or mechanically more favorable when forming the low-temperature cooling device.
  • Diagrams to illustrate the time course of the cooling process on the first cold head of a first pulse tube and on the second cold head of a second cold tube. represent the head of a pulse tube cooler or low-temperature cooling device.
  • 5a shows the cooling profile in a conventional cooling device
  • FIG. 5b shows the cooling profile in a cooling device according to the invention according to FIGS. 3 or 4.
  • the first pulse tube 20 which is essentially insulated from the second pulse tube 30, since its cooling capacity is optimized for lower temperatures, does not reach a temperature of approximately 77 K at the first cold head 24 until ⁇ tl later t2, as is shown in FIG Line 220 is shown in order to then have a temperature of approximately 4 K at time t3.
  • the situation is different for a low-temperature cooling device according to the present invention, in particular according to FIGS. 3 or 4.
  • the heat switch 100 is closed for thermal coupling to create between the second cold head 34 and the first cold head 24 or the first cold end portion 46 of the first regenerator 40.
  • the cooling process is now started and the low-temperature cooling device, in particular the object 82 to be cooled on the first cold head 24, is driven cold or cooled down, this is now done by the combined cooling capacity of the first 20 and second 30 pulse tubes or their cold heads 24, 34.
  • This fact also illustrates the thick solid line 220 ', 230' (lower line) in Figure 5b.
  • the heat switch 100 When the time t1 is reached, the heat switch 100 is opened and the first cold head 24 alone cools the object 82 to be cooled to the desired temperature of 4 K (TE), which occurs at time t4 according to the curve 220 '.
  • TE desired temperature
  • the first cold head 24 (curve 220 ') already the intermediate temperature of 77 K (tZl) by a time interval .DELTA.l and earlier a time interval ⁇ t2 correspondingly reaches the target temperature of 4 K earlier.
  • the cooling time for cooling an object 82 to be cooled can be reduced by up to half from 300 K to 4 K compared to a conventional cooling device.
  • FIG. 6 shows a schematic illustration of a third embodiment of a low-temperature cooling device according to the invention.
  • a warm head 22 (located at the upper end of a first pulse tube 20 and not explicitly identified) of a first pulse tube 20, a warm head 32 (located at the upper end of a second pulse tube 30 and not explicitly identified) of a second pulse tube 30, a warm head 112 (located at the upper end of a third pulse tube 110 and not explicitly identified) of a third pulse tube 110, and a warm end section 124 of a third regenerator 120 in thermal contact with the 300 K temperature level, for example a cryostat cover that is in contact with the environment.
  • the three regenerators 40, 50 and 120 are connected to one another, so that the upper regenerators 50, 120 are used as the warm regenerator section 50, 120 or for coupling to the 30OK temperature level from the regenerator 40, and the upper regenerator 120 as the warm regenerator section 120 or for coupling to the 30OK temperature level from the regenerator 50 is also used.
  • the first, second and third pulse tubes 20, 30 and 110, and the regenerators or regenerator sections 40, 50 and 120 are arranged essentially parallel and in the direction of gravity.
  • a first cold head 24 is provided, on which a cooling temperature of approximately 4 K (TE) is provided on an object to be cooled, here on a magnet 82.
  • a cold head 34 is provided, at which a cooling temperature of approximately 30 K (TZl) 51
  • the temperature of 30 K is provided to a cooling region which contains the cold head 24 of the first pulse tube and the magnet 82 and which is surrounded by a heat shield for thermal insulation in the case of using a cryostat.
  • a cold head 114 is provided, at which a cooling temperature of approximately 77 K (TZ2) is provided for precooling the first and second pulse tubes 20 and 30, respectively.
  • TZ2 cooling temperature of approximately 77 K
  • the temperature of 77 K can be provided to a cooling region which includes the cold heads 24, 34 of the first, second pulse tube and the magnet 82 and which, in the case of using a cryostat, is surrounded by a heat shield (not shown) for thermal insulation.
  • the cold head 24 of the first pulse tube 20 is connected to a cold end section 46 of the regenerator 40 via a line 42
  • the cold head 34 of the second pulse tube 30 is connected to a cold end section 56 of the second regenerator 50 via a line 52
  • is Cold head 114 of the third pulse tube 110 is connected via a line 122 to a cold end section 126 of the third regenerator 120.
  • the lines 42, 52, 122 are gas lines which are provided for transmitting the oscillating gas from the respective regenerators 40, 50, 120 to the pulse tubes 20, 30, 110.
  • the cold head 34 of the second pulse tube 30 is thermally coupled (interruptible) to the cold head 24 of the first pulse tube 20 via a heat switch 100, which in turn is preferably designed as a mechanical heat switch.
  • the heat switch 100 is coupled to the respective components 34 and 24 via lines 101, 101 ', 109.
  • the cold head 114 of the third pulse tube 110 is via a heat switch 104 again preferably designed as a mechanical heat switch, thermally coupled to the cold head 24 of the first pulse tube 20 (interruptible).
  • the heat switch 104 is coupled to the respective components 114 and 24 via lines 105, 105 ', 109, the line 109 which is coupled to the cold head 24 also being connected to the line 101' to simplify the construction.
  • the cold head 114 of the third pulse tube 110 is connected to the cold head 34 of the second pulse tube 30 or the cold end section 56 of the second regenerator 50 via a heat switch 102, which in turn is preferably designed as a mechanical heat switch. interruptible) thermally coupled.
  • the heat switch 102 is coupled to the respective components 114 and 52 via lines 103, 103 '.
  • the line 103 ' can also be connected directly to the cold head 24 or the cold end section 56.
  • the lines 101, 101 ', 103, 103', 105, 105 ' are preferably designed as wire or tubular lines made of a thermally highly conductive (eg copper, gold) material.
  • a cooling process of a low-temperature cooling device is as follows. Before the actual cooling process begins, which begins at approximately room temperature, ie approximately 300 K, the heat switches 100, 102 and advantageously also the heat switch 104 are closed in order to provide a thermal Coupling between the second 34 and first 24 cold heads, the third 114 and second 34 cold heads or the cold end section 46, and for better or faster thermal connection also to create a thermal coupling directly between the third 114 and first 24 cold heads. Now the cooling process is started and the low-temperature cooling device, especially that too Z3
  • Cooling object 82 on the first cold head 24, driven cold or cooled is now done by the combined cooling capacity of the first 20, second 30, and third pulse tube or their cold heads 24, 34, 114.
  • the target temperature TZ2 of the third cold head 114 has been reached, the heat switches 102, 104 are opened and the first and second cold heads 24, 34 continue (in a second cooling phase) to cool the object 82 to the target temperature of the second cold head 34 from cool about 30 K (TZl).
  • the heat switch 100 is opened and only the first cold head 24 continues (in a third cooling phase) to cool the object 82 to be cooled to the target temperature of the first cold head 24 of approximately 4 K ( TZl) to cool.
  • the best possible cooling performance is provided by the supporting performance of the pulse tubes optimized for lower temperatures in the respective cooling phases and by corresponding decoupling thereof, as a result of which the cooling time of the inventive low-temperature cooling device for cooling the object 82 is minimized.
  • FIG. 7 shows a schematic illustration of a pulse tube cooler according to a first embodiment. Here how lk
  • the cooling effect in the pulse tube cooler is based on the periodic change in pressure and displacement ("pulsation") of a working gas in a thin-walled cylinder with heat exchangers at both ends, the so-called pulse tube 20.
  • the pulse tube 20 is connected to the pressure oscillator 10 via a regenerator 40.
  • the regenerator 40 serves as an intermediate heat store, which cools the gas flowing in from the pressure oscillator 10 before entering the pulse tube 20 and then warms the outflowing gas back to room temperature.
  • it is advantageously filled with a material with a high heat capacity, which has a good heat exchange with the flowing gas and at the same time a low flow resistance.
  • stacks of fine-mesh stainless steel or bronze sieves are used as the regenerator filling.
  • a compressor 10 is used in combination with a downstream rotary valve 15, which periodically connects the high and low pressure sides of the compressor to the cooler.
  • the pressure oscillation can be generated directly via the piston movement of a valveless compressor.
  • the pulse tube is closed at the warm end 22.
  • the quality of the cooling process is as follows: in the compression phase, the gas which has been precooled in the regenerator 40 flows into the pulse tube 20. By increasing the pressure, the gas in the pulse tube 20 is heated and at the same time displaced towards the warm heat exchanger 22 or warm head 22, where part of the compression heat is dissipated to the environment.
  • the gas in the pulse tube 20 is cooled.
  • the gas which leaves the pulse tube 20 is colder than when it enters and can therefore heat from the cold heat exchanger 24 or cold head 24 and the object to be cooled or a further cooling device , take up.
  • a more detailed analysis of the process in this embodiment shows that the heat transfer from the cold 24 to the warm 22 end requires a heat exchange between the gas and the pipe wall ("surface heat pumps"). However, since the heat contact only occurs in a thin gas layer on the pipe wall, this cooling process has not yet been optimized.
  • FIG. 8 now shows a schematic illustration of a pulse tube cooler 20 according to a second embodiment.
  • This results in a significant increase in effectiveness by connecting a ballast volume 70 via a flow resistance (needle valve) 26 to the warm heat exchanger 22.
  • a flow resistance needle valve
  • the warm heat exchanger 22 can then give off heat of compression there.
  • the gas in the pulse tube 20 does work when gas is shifted into the ballast volume 70, as a result of which a significantly higher cooling effect is achieved.
  • FIG. 9 shows a schematic illustration of a pulse tube cooler according to a third embodiment, in which the effectiveness of the cooler can be increased further by the portion of the gas flow which is necessary for changing the pressure in the warm part of the pulse tube 20 through a second inlet at the warm end is directed. Since this gas flow no longer passes through the regenerator 40, the losses in the regenerator 40 are reduced. In addition, with a second inlet (with a valve 28), a chronological sequence of pressure and flow variation which is more favorable for cooling is established.
  • FIG. 10 shows a schematic overall structure of a pulse tube cooler according to the third embodiment in a more concrete representation than in FIG. 9. In this system, a commercial helium compressor 10 feeds a motor-driven rotary valve 15, which is used to control the helium gas flow.
  • the actual cooler and the rotary valve can be connected to one another via a flexible plastic line 12.
  • FIG 11 shows a schematic representation of a two-stage pulse tube cooler system with the most important components.
  • a compressor 10 is coupled to a rotary valve 15.
  • a line 12 connects the rotary valve 15 to the pulse tube cooler system.
  • This has a regenerator 40 of the first stage and a regenerator 50 of the second stage, a flow straightener 45 being arranged between them. It is also conceivable to choose a different regenerator arrangement in which, for example, two separate regenerators are used.
  • the pulse tube cooler system has a first pulse tube 20 with a warm heat exchanger 22 and a cold heat exchanger or cold head 24 and a second pulse tube 30 with a warm heat exchanger 32 and a cold heat exchanger or cold head 34.
  • the respective warm heat exchangers 22 and 32 are connected to a common ballast container or ballast volume 70 via throttle valves, for example in the form of needle valves 26 and 36. It is also conceivable that two separate ballast volumes are used instead of the common ballast volume.
  • valves 38 and 28 are provided on the respective warm heat exchangers 22 and 32 for a second inlet. The cold head 24 of the second pulse tube 30 cools one of a heat or vk
  • Radiation shield 92 area up to about a maximum of 50 K, while a temperature of about 2.2 to 4.2 K is provided at the cold head 24 of the first pulse tube 20 (cf. C. Wang et al.: "A two-stage pulse tube cooler operating below 4 K ", Cryogenics 1997, Volume 37, No. 3).

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)

Abstract

L'invention concerne un dispositif de refroidissement cryogénique qui comprend: un premier dispositif de refroidissement pourvu d'un premier tube à impulsions (20) qui comporte une première tête froide (24) servant à produire une première zone de refroidissement à une première température (TE), et est pourvue d'un premier régénérateur (40) qui comporte une première partie terminale froide (46) qui est reliée à la première tête froide (24) du premier tube à impulsions (20); et un second dispositif de refroidissement (30), qui présente une seconde zone de refroidissement (34) fournissant une seconde température (TZ1) qui est supérieure à la première température (TE). Un objet (82) à refroidir peut être couplé thermiquement avec la première tête froide du premier tube à impulsions. Pour que le temps de refroidissement soit le plus court possible la seconde zone de refroidissement (34) peut être thermiquement couplée, par l'intermédiaire d'un premier commutateur thermique (100), avec le premier tube à impulsions (20) et/ou le premier régénérateur (40) et/ou l'objet (82) à refroidir. Le dispositif selon l'invention peut également comprendre un troisième dispositif de refroidissement (110) pourvu d'un second commutateur thermique (102) et d'un troisième commutateur thermique (104).
PCT/EP2000/011143 1999-11-10 2000-11-10 Dispositif de refroidissement cryogenique WO2001035034A1 (fr)

Priority Applications (1)

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AU23556/01A AU2355601A (en) 1999-11-10 2000-11-10 Cryogenic cooling device

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DE19954077.2 1999-11-10
DE1999154077 DE19954077C1 (de) 1999-11-10 1999-11-10 Tieftemperaturkühlvorrichtung

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106969567A (zh) * 2015-12-14 2017-07-21 牛津仪器纳米技术工具有限公司 加速冷却的方法

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10309134A1 (de) * 2003-02-28 2004-09-16 Frank Russmann Verfahren zur Verflüssigung von Gasen
DE10338221A1 (de) * 2003-08-20 2005-03-10 Leybold Vakuum Gmbh Kryogener Refrigerator
DE102004054750A1 (de) * 2004-11-12 2006-05-24 Vericold Technologies Gmbh Kryodetektorvorrichtung
DE202004018469U1 (de) * 2004-11-29 2006-04-13 Vericold Technologies Gmbh Tieftemperatur-Kryostat
CN115200247B (zh) * 2022-07-11 2024-05-07 中国科学院上海技术物理研究所 一种节流制冷耦合绝热去磁制冷机的低温结构及实现方法

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4399661A (en) * 1982-08-03 1983-08-23 The United States Of America As Represented By The Secretary Of The Army Prolonged cold temperature cryogenic cooler
US4770004A (en) * 1986-06-13 1988-09-13 Hughes Aircraft Company Cryogenic thermal switch
US5485730A (en) * 1994-08-10 1996-01-23 General Electric Company Remote cooling system for a superconducting magnet
DE19538664A1 (de) * 1994-10-18 1996-04-25 Air Liquide Tiefstkältetechnische Vorrichtung für eine optronische und/oder elektronische Einrichtung und für Einrichtungen, die eine derartige Vorrichtung enthalten
US5642623A (en) * 1995-02-23 1997-07-01 Suzuki Shokan Co., Ltd. Gas cycle refrigerator
US5842348A (en) * 1994-10-28 1998-12-01 Kabushiki Kaisha Toshiba Self-contained cooling apparatus for achieving cyrogenic temperatures
US5845498A (en) * 1996-04-30 1998-12-08 Aisin Seiki Kabushiki Kaisha Pulse tube refrigerator
EP0905436A2 (fr) * 1997-09-30 1999-03-31 Oxford Magnet Technology Limited Moyens portants pour RMN systèmes de cryostats

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4771823A (en) * 1987-08-20 1988-09-20 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Self-actuating heat switches for redundant refrigeration systems
JP2902159B2 (ja) * 1991-06-26 1999-06-07 アイシン精機株式会社 パルス管式冷凍機
DE4224450C2 (de) * 1992-07-24 1996-05-23 Daimler Benz Aerospace Ag Aktive Temperaturkontrolle mittels eines elektrisch steuerbaren Wärmeflußreglers
DE4224449C2 (de) * 1992-07-24 1996-06-20 Daimler Benz Aerospace Ag Aktive Temperaturkontrolle mittels eines elektrisch steuerbaren Wärmeflußreglers
DE19612539A1 (de) * 1996-03-29 1997-10-02 Leybold Vakuum Gmbh Mehrstufige Tieftemperaturkältemaschine
JPH10132404A (ja) * 1996-10-24 1998-05-22 Suzuki Shiyoukan:Kk パルス管冷凍機

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4399661A (en) * 1982-08-03 1983-08-23 The United States Of America As Represented By The Secretary Of The Army Prolonged cold temperature cryogenic cooler
US4770004A (en) * 1986-06-13 1988-09-13 Hughes Aircraft Company Cryogenic thermal switch
US5485730A (en) * 1994-08-10 1996-01-23 General Electric Company Remote cooling system for a superconducting magnet
DE19538664A1 (de) * 1994-10-18 1996-04-25 Air Liquide Tiefstkältetechnische Vorrichtung für eine optronische und/oder elektronische Einrichtung und für Einrichtungen, die eine derartige Vorrichtung enthalten
US5842348A (en) * 1994-10-28 1998-12-01 Kabushiki Kaisha Toshiba Self-contained cooling apparatus for achieving cyrogenic temperatures
US5642623A (en) * 1995-02-23 1997-07-01 Suzuki Shokan Co., Ltd. Gas cycle refrigerator
US5845498A (en) * 1996-04-30 1998-12-08 Aisin Seiki Kabushiki Kaisha Pulse tube refrigerator
EP0905436A2 (fr) * 1997-09-30 1999-03-31 Oxford Magnet Technology Limited Moyens portants pour RMN systèmes de cryostats

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
FRANK POBELL: "Matter and methods at low temperatures", vol. 2.AUFLAG, 1996, SPRINGER-VERLAG
TANIDA K ET AL: "THREE-STAGED PULSE TUBE REFRIGERATOR CONTROLLED BY FOUR-VALVE METHOD", PROCEEDINGS OF THE 1995 CRYOGENIC ENGINEERING CONFERENCE, COLUMBUS JULY 17 - 21, 1995,NEW YORK, PLENUM,US, vol. 41, 17 July 1995 (1995-07-17), pages 1503 - 1509, XP000637596, ISBN: 0-306-45300-2 *
YOICHI MATSUBARA ET AL: "MULTI-STAGED PULSE TUBE REFRIGERATOR FOR SUPERCONDUCTING MAGNET APPLICATIONS", CRYOGENICS,GB,IPC SCIENCE AND TECHNOLOGY PRESS LTD. GUILDFORD, vol. 34, no. ICEC-SUPPL, 7 June 1994 (1994-06-07), pages 155 - 158, XP000511555, ISSN: 0011-2275 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106969567A (zh) * 2015-12-14 2017-07-21 牛津仪器纳米技术工具有限公司 加速冷却的方法
CN106969567B (zh) * 2015-12-14 2021-04-30 牛津仪器纳米技术工具有限公司 加速冷却的方法

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