EP0614059A1 - Cooler with a cold finger of pulse tube type - Google Patents

Cooler with a cold finger of pulse tube type Download PDF

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Publication number
EP0614059A1
EP0614059A1 EP94400432A EP94400432A EP0614059A1 EP 0614059 A1 EP0614059 A1 EP 0614059A1 EP 94400432 A EP94400432 A EP 94400432A EP 94400432 A EP94400432 A EP 94400432A EP 0614059 A1 EP0614059 A1 EP 0614059A1
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EP
European Patent Office
Prior art keywords
tube
regenerator
cold finger
pressure
oscillator
Prior art date
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Granted
Application number
EP94400432A
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German (de)
French (fr)
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EP0614059B1 (en
Inventor
Damien Feger
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Cryotechnologies SA
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Cryotechnologies SA
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    • 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 
    • F25B2309/1406—Pulse-tube cycles with pulse tube in co-axial or concentric 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
    • 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
    • F25B2309/00—Gas cycle refrigeration machines
    • F25B2309/14—Compression machines, plants or systems characterised by the cycle used 
    • F25B2309/1417—Pulse-tube cycles without any valves in gas supply and return lines
    • 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 
    • F25B2309/1424—Pulse tubes with basic schematic including an orifice and a reservoir
    • F25B2309/14241—Pulse tubes with basic schematic including an orifice reservoir multiple inlet pulse tube

Definitions

  • the present invention relates to coolers based on the Stirling cycle. These coolers allow cryogenic temperatures to be reached.
  • coolers include an electromechanical oscillator which generates, in an active enclosure containing a fluid, a pressure wave.
  • the enclosure comprises a part provided with a mobile regenerator or displacer which uses the expansion and compression cycles of the fluid to carry out a Stirling cycle.
  • the fluid used is generally helium, at an average pressure of several hundred kilopascals.
  • the oscillator can be rotary or linear.
  • the cold part generally has, in order to limit the heat losses by conduction and to facilitate its manufacture, the shape of a very elongated cylinder which earns it the name of "cold finger".
  • the free end of the cold finger provides cooling power created by the expansion of the fluid.
  • the base of the cold finger connected to the oscillator, dissipates the heat created by the compression of the fluid.
  • the cold finger is generally immersed in a cryostat, such as a Dewar vessel for example, which contains the device to be cooled.
  • the interior of the cryostat is generally subjected to vacuum to limit the entry of heat.
  • the oscillator and the cold finger are one piece.
  • the movement of regenerator is generally provided, in the case of a rotary oscillator, by the oscillator piston. This configuration is very compact, it limits the pressure drops between the oscillator and the cold finger. However, the vibrations induced by the oscillator are transmitted to the device to be cooled.
  • the oscillator and the cold finger are separated but connected by a pneumatic conduit which ensures the transfer of the pressure wave between the oscillator and the cold finger.
  • the movement of the regenerator can be ensured by a specific motor or by the pneumatic effects generated by the pressure wave.
  • the first configuration is generally used in space applications. These two configurations make it possible to separate the oscillator and the equipment to be cooled, which facilitates the integration of the cooler into the environment of the device to be cooled. In addition, these two configurations make it possible to considerably reduce the vibrations at the level of the device to be cooled.
  • Mobile regenerator coolers have a relatively high cost because of the machining tolerances required to produce the regenerator and the cold finger which are in movement with respect to each other.
  • Pulsed tube type cold finger coolers are also known.
  • the cold finger instead of containing a mobile regenerator contains a fixed regenerator and a pulsed tube.
  • coolers are numerous.
  • the lifespan of the cold finger is almost unlimited because the elimination of movement reduces wear.
  • the vibrations induced in the cold finger are much lower than those induced in the cold fingers with mobile regenerator.
  • the costs are also much lower due to an operation less sensitive to geometric manufacturing tolerances.
  • Fixed regenerator reduces losses efficiency linked to the shuttle effect and fluid leaks between the outer wall of the cold finger and the regenerator.
  • These coolers insofar as they use a pulsed tube with double orifice, have an efficiency substantially equivalent to that of a cold finger cooler provided with a mobile regenerator.
  • a double orifice pulsed tube cooler is described later in Figure 1.
  • the major drawback of this type of cooler is linked to the U shape of the cold finger.
  • One of the branches of the U is produced by the regenerator and the other by the pulsed tube.
  • the base of the U which is also the free end of the cold finger is formed of an end piece integral with one side of the regenerator and the other of the pulsed tube.
  • This cold finger imposes a specific cryostat and therefore prevents its implantation in a cryostat intended for a cold finger with mobile regenerator or of the Joule-Thomson type. Maintenance "on the ground” of the cold finger with pulsed tube is not possible while intervention on a cold finger with mobile regenerator is easy. Indeed, it would be necessary to break the vacuum of the cryostat to dismantle the pulsed tube or the regenerator.
  • the present invention aims to remedy these drawbacks. It offers a cooler based on the Stirling cycle, fitted with a cold finger of the pulsed tube type. This cooler can be installed in a conventional cryostat and it has good thermodynamic performance.
  • the cooler according to the invention comprises means for generating a pressure wave in a fluid and transmitting it to a cold finger of the pulsed tube type.
  • the cold finger comprises a regenerator pneumatically connected to the pulsed tube, this regenerator is tubular and is mounted coaxially around the pulsed tube.
  • the regenerator can, for example, be contained between an outer tube and an inner tube, the inner tube serving as a pulsed tube.
  • the regenerator can be contained in an outer tube, the inner surface of the regenerator serving as a pulsed tube.
  • the external tube serves as an interior wall for the cryostat. This configuration, which removes the inner wall of the cryostat, improves cooling performance by reducing losses by conduction.
  • FIG. 1 represents a cooler based on the Stirling cycle provided with a cold finger 1 of the pulsed tube type 5, according to known art.
  • the cold finger 1 is connected to a pressure oscillator 2 through a base 3.
  • the base 3 provides the mechanical interface and the seal between the cold finger 1 and a cryostat in which the cold finger 1 is generally immersed.
  • 'base 3 forms the base of the cold finger 1.
  • the cryostat is not shown for reasons of clarity.
  • the pressure oscillator 2 generates a pressure wave in a fluid and the fluid is successively compressed and expanded.
  • the cold finger 1 comprises a fixed regenerator 4 contained in a tube 7 and a pulsed tube 5 which form the two branches of a U.
  • the regenerator 4 has the shape of a full cylinder.
  • the base of the U is produced by a cold end piece 6 which pneumatically connects the regenerator 4 and the pulsed tube 5.
  • the tube 7 containing the regenerator has a hot end fixed to the base 3 and a cold end fixed to the end piece 6.
  • the end piece 6 constitutes the free end of the cold finger 1. This is the point the cooler the cooler. It also serves to transmit to the device to be cooled, placed nearby, the frigories made available by the expansion of the fluid.
  • the fixed regenerator 4 operates in the same way as a mobile regenerator. It is made of a porous material permeable to fluid.
  • the regenerator 4 is pneumatically connected to the oscillator 2.
  • regenerator The function of the regenerator is to capture cold from the fluid when the latter is sucked in by the oscillator 2 during the expansion phase and to evacuate heat to this fluid when it is discharged during the compression phase.
  • the pulsed tube 5 simply consists of a tube substantially parallel to the tube 7 containing the regenerator 4. It is integral with one cold end of the end piece 6 and the other hot end of the base 3.
  • a pneumatic circuit 8 is used to connect the pressure oscillator 2 to the regenerator 4 and to the pulsed tube 5.
  • a buffer tank 9 is also provided and connected to the pneumatic circuit 8. It has a sufficient volume so that the fluid which it contains remains at a substantially constant pressure whatever the phase of the pressure oscillator 2. When the oscillator sucks in the fluid, the fluid in the buffer tank 9 feeds the pulsed tube 5 and when the oscillator 2 discharges, the discharged fluid fills the buffer tank 9.
  • the pneumatic circuit comprises a first conduit 8 connecting the regenerator 4 to the oscillator 2, a second conduit 82 connecting the hot end of the pulsed tube 5 to the buffer tank 9 and a third conduit 83 connecting the hot end of the pulsed tube to the pressure oscillator 2.
  • the pulsed tube is connected both to the oscillator and to the buffer tank.
  • the fluid passes through a hot heat exchanger 10 between the hot end of the pulsed tube 5 and the oscillator 2 and / or the buffer tank 9.
  • This hot exchanger 10 can be housed in the base 3.
  • the third conduit 83 is disposed between the first conduit 81 and the second conduit 82 and it reaches the second conduit 82 between the buffer tank 9 and the hot heat exchanger 10.
  • the hot heat exchanger 10 collects the heat of compression of the fluid leaving the pulsed tube and its evacuation, via the base 3, to the outside of the cooler.
  • the movement of the fluid in the cold finger is out of phase with respect to the pressure wave generated by the oscillator 2.
  • the phase shift and the flow rates at the hot ends of the pulsed tube 5 and of the tube 7 containing the regenerator 4 are a function of the pneumatic impedance of the conduits 81, 82 and 83 and of the volume of the buffer tank 9.
  • the pneumatic impedance of the conduits can be adjusted by an appropriate choice of their section, their length.
  • the conduits can also include simple pinches or orifices 11 calibrated as in FIG. 1 or even valves.
  • the behavior of the fluid in the pulsed tube is as follows: let us consider a volume A of fluid which transits between the cold end of the pulsed tube 5 and the end piece 6. Due to the phase shift of the movement of the fluid in the cold finger with the expansion and compression phases of the oscillator 2, this fluid when it relaxes passes to the end piece 6 while cooling it and when it compresses, enters the pulsed tube 5 where it heats up almost adiabatic way.
  • FIG. 2 schematically represents a cooler according to the invention.
  • This cooler is comparable to that of FIG. 1.
  • the main difference is at the level of the cold finger 21 which, instead of comprising a regenerator and a pulsed tube configured in U, comprises a tubular regenerator 24 mounted coaxially around the pulsed tube 25.
  • the cold finger 21 is always connected to an oscillator 2 through a base 3.
  • the base 3 plays the same role as in FIG. 1.
  • the free end of the cold finger always ends with an end piece 26. It is always the coldest part of the cooler.
  • the regenerator 24 plays the same role as in the known art. Instead of having the shape of a full cylinder it now has the shape of a tube.
  • the regenerator 24 is contained between an outer tube 27 and an inner tube 28.
  • the cylindrical outer tube 27 has a hot end tightly fixed to the base 3 and a cold end tightly fixed to the end piece 26. It forms the outer surface of the cold finger 21.
  • This outer tube 27 preferably has a thickness as thin as possible to limit thermal entry along the cold finger. It is preferably carried out in a material with as low a thermal conductivity as possible, for example stainless steel.
  • This external tube 27 as well as its attachments to the base 3 and to the end piece 26 must seal the interior of the cold finger vis-à-vis the external environment.
  • the cold finger is generally immersed in a cryostat subjected to vacuum. This cryostat is represented with the reference 30 in FIG. 4 in the form of a Dewar vase.
  • the inner tube 28 serves both as a pulsed tube and as an inner wall to the tubular regenerator 24. It is arranged coaxially in the external tube 27 and has a hot end fixed to the base 3. Its other end which is cold opens into the end piece 26.
  • This internal tube 28 is not subjected like the external tube 27 to significant pressure differences. It does not have to be tightly sealed like the outer tube. It avoids direct passage of the fluid from the regenerator 24 to the pulsed tube 25 without passing through the end piece 26.
  • the design of this internal tube 28 with respect to the choice of the constituent material, its method of fixing, and its thickness can be more easily optimized. One can even consider physically removing the inner tube 28 if the inner surface of the regenerator 24 is sealed. In this case, it is the interior surface of the regenerator which serves as a pulsed tube.
  • the end piece 26 resembles the end pieces of the cold fingers with mobile regenerator.
  • the regenerator and the pulsed tube communicate pneumatically thanks to it.
  • the thickness of the end piece 26 will be as small as possible. It will be made of a material having as high a thermal conductivity as possible: copper for example. It is conceivable that the end piece contains a cold exchanger 29 formed for example of copper grids brazed at their periphery. This cold exchanger 29 improves the heat exchange between the fluid and the end piece 26.
  • the material of the end piece 26 will preferably have a coefficient of expansion as low as possible when the cold finger 21 is used to cool a device placed directly on the end piece 26 (technique known by the English name Integrated Dewar Cooler Assembly).
  • the end piece 26 may, for example, be provided with a tranquilizer device to ensure the lowest possible level of turbulence in the pulsed tube 25. It is indeed desirable to maintain a large thermal gradient between the two hot ends and cold from the pulsed tube.
  • This transquilliser device can be produced by a honeycomb part or by the cold exchanger 29.
  • the other elements of the cooler, namely the oscillator 2, the pneumatic circuit 8, the buffer tank 9 and the hot exchanger 10 are comparable to those in Figure 1.
  • the hot heat exchanger 10 if it is configured with grids or a honeycomb material also has a role of tranquilizer.
  • the optimal adjustment of the phase shift and the amplitude of the fluid flow rates in the regenerator 24 and the pulsed tube 25 will depend on the volume of the buffer tank 9 and on the characteristics of the conduits 81, 82, 83 as before.
  • the pulsed tube has a length of 70 mm and that in operation its extreme temperatures are 80 ° K at the cold end and 300 ° K at the hot end. It is assumed that the thermal gradient is linear in the wall of the pulsed tube, that the average pressure in the pulsed tube is 35.105Pa and that it varies more or less 106Pa, because of the pressure wave.
  • the slice of fluid will have an average temperature of 190 ° K but during the expansion and compression cycles, it will see its temperature oscillate between 166 ° K and 210 ° K (curve C1). This slice of fluid will be vis-à-vis with a section of pulsed tube whose temperatures will be between 158 ° K and 221 ° K (curve C2) because of the linear thermal gradient.
  • the fluid In the expansion phase, the fluid will be in contact with a portion of the pulsed tube cooler than it and will tend to give it heat.
  • the fluid Symmetrically, in the compression phase, the fluid will be in contact with a portion of the pulsed tube hotter than it and will tend to extract heat from it. This heat pumping effect from the hot end of the pulsed tube to the cold end is detrimental to the performance of the cooler.
  • These heat exchanges with the walls concern only part of the fluid: the thermal boundary layer which is close enough to the wall to have time to exchange, mainly by gas conduction, heat during a compression-expansion cycle.
  • a cooler according to the invention makes it possible to reduce the exchanges between the fluid and the wall of the pulsed tube by placing the pulsed tube inside the regenerator and not around it.
  • the cold finger is formed of two coaxial tubes (of zero thickness for simplicity) of diameters 5mm and 3.5mm, in the case of a thickness of thermal boundary layer of 0.2 mm, it can be estimated that only 20% of fluid participates in the heat exchange with the wall of the pulsed tube, if the pulsed tube is placed inside the regenerator, while more than 50% of fluid participates in the heat exchange with the external and internal walls of the tube pulsed, if the regenerator is placed inside the pulsed tube.
  • FIGS. 4 to 7 show various variants of a cooler according to the invention. We refer to figure 4.
  • the cold finger is immersed in a cryostat such as a Dewar vessel 30 comprising two chambers 31, 32 inserted one inside the other and separated by a vacuum.
  • the internal enclosure 32 has the shape of a well.
  • the cooling device referenced 33 is disposed between the external enclosure 31 and the internal enclosure 32. It is fixed to the bottom of the well.
  • a thermal coupler 34 is inserted between the free end of the cold finger 21 and the bottom of the well to optimize the cooling of the device to be cooled 33.
  • the pressure oscillator 2 is rotary.
  • the buffer tank is constituted by the casing 35 of the oscillator, which saves space.
  • the second conduit 82 and the third conduit 83 each comprise a valve 36 instead of a calibrated orifice and, moreover, the second conduit 82 is provided with a pinch 37 between the valve and the hot exchanger 10.
  • the cold finger and the base are represented by a single block 50 for simplicity.
  • the pressure oscillator 51 is a resonant linear oscillator.
  • the buffer tank 52 is provided with a heating device 54.
  • the temperature of the fluid in the buffer tank 52 is adjustable so as to be able to adjust the average pressure in the cooler and to be able to adjust the resonant frequency of the cooler. this is particularly advantageous in the case where the cooler is used in a satellite where an adjustable frequency is sought in order to avoid exciting the platform or instruments near the cooler.
  • the hot exchanger is constituted by a fin device 55 or equivalent.
  • This device 55 is arranged on the second conduit 82 connecting the pulsed tube to the buffer tank 52.
  • the other conduits 81, 83 and the reservoir 52 could also participate in the evacuation of the heat of compression of the fluid. To this end, they would be fitted with devices, with fins for example, improving the dissipation of this heat to the outside.
  • the buffer tank 52 is provided with a tranquilizer device 56 to ensure a level of turbulence as low as possible in the pulsed tube.
  • This tranquilizer device 56 can be of the same nature as that described in the end piece 26 of FIG. 2.
  • the cold finger 60 immersed in a cryostat 61, and the rotary pressure oscillator 68 form a monobloc cooler.
  • the compressor casing 69 constitutes the buffer tank.
  • the cold finger 60 comprises an external tube 62, a tubular regenerator 63 and a pulsed tube 66.
  • the external tube 62 serves as an interior wall for the cryostat.
  • the inner surface of the tubular regenerator serves as a pulsed tube 66.
  • the removal of the inner wall of the cryostat can of course be used in other configurations.
  • the cooling device 65 is directly fixed to the end piece 64 which connects the pulsed tube and the regenerator. Cooling is improved compared to the configuration where the outer tube and the inner wall of the cryostat are separate.
  • a cooling device 67 with fluid circulation has been placed around the hot exchanger 10. This cooling device is preferably used when the pulsed tube is subjected to significant powers, for example greater than a few watts.
  • a fluid circulation cooling device one could have used a cooling device with natural or forced convection with air for example.
  • the configuration shown is particularly compact, it minimizes the pressure drops between the oscillator 68 and the cold finger 60.
  • the cooler now comprises several pressure oscillators 70, 71, 72 mounted in parallel.
  • a switch 73 having several input channels and an output channel makes it possible to connect the cold finger to one of the pressure oscillators 71.
  • the pressure oscillator With a cold finger without moving part, the only element presenting a relatively high risk of failure is the pressure oscillator which has moving parts.
  • the switching from one pressure oscillator to another can be controlled by the user or automatically when the operation of the oscillator in service is no longer normal. This switching does not require any intervention or disassembly on the cold finger and the cryostat, it can be carried out instantly and remotely.
  • the cooler according to the invention can cool any device, in particular sensors or detectors, electronic components, samples, etc.

Abstract

The present invention relates to a cooler based on the Stirling cycle. It comprises means (2,8,9) for generating a pressure wave in a fluid and transmitting it to a cold finger (21) of the pulse (pulsed) tube type. The cold finger (21) comprises a tubular regenerator (24) which is mounted coaxially around the pulse tube (25). Applications: Cooling, especially of electronic components such as infrared detectors. <IMAGE>

Description

La présente invention est relative aux refroidisseurs basés sur le cycle de Stirling. Ces refroidisseurs permettent d'atteindre des températures cryogéniques.The present invention relates to coolers based on the Stirling cycle. These coolers allow cryogenic temperatures to be reached.

Ils sont notamment utilisés pour refroidir des composants électroniques tels que des détecteurs infrarouges qui fonctionnent à ces températures.They are used in particular to cool electronic components such as infrared detectors which operate at these temperatures.

Ces refroidisseurs comprennent un oscillateur électromécanique qui génère, dans une enceinte active contenant un fluide, une onde de pression. L'enceinte comporte une partie munie d'un régénérateur mobile ou déplaceur qui utilise les cycles de détente et de compression du fluide pour réaliser un cycle de Stirling.These coolers include an electromechanical oscillator which generates, in an active enclosure containing a fluid, a pressure wave. The enclosure comprises a part provided with a mobile regenerator or displacer which uses the expansion and compression cycles of the fluid to carry out a Stirling cycle.

Le fluide utilisé est généralement de l'hélium, sous une pression moyenne de plusieurs centaines de kilopascals. L'oscillateur peut être rotatif ou linéaire.The fluid used is generally helium, at an average pressure of several hundred kilopascals. The oscillator can be rotary or linear.

La partie froide a généralement, pour limiter les pertes thermiques par conduction et faciliter sa fabrication, la forme d'un cylindre très allongé ce qui lui vaut l'appellation de "doigt froid". L'extrémité libre du doigt froid fournit de la puissance frigorifique créée par la détente du fluide. La base du doigt froid reliée à l'oscillateur, évacue de la chaleur créée par la compression du fluide. Le doigt froid est généralement plongé dans un cryostat, tel qu'un vase de Dewar par exemple, qui contient le dispositif à refroidir. L'intérieur du cryostat est généralement soumis au vide pour limiter les entrées de chaleur.The cold part generally has, in order to limit the heat losses by conduction and to facilitate its manufacture, the shape of a very elongated cylinder which earns it the name of "cold finger". The free end of the cold finger provides cooling power created by the expansion of the fluid. The base of the cold finger connected to the oscillator, dissipates the heat created by the compression of the fluid. The cold finger is generally immersed in a cryostat, such as a Dewar vessel for example, which contains the device to be cooled. The interior of the cryostat is generally subjected to vacuum to limit the entry of heat.

On distingue deux familles de refroidisseurs: les refroidisseurs monoblocs et les refroidisseurs "séparés".There are two families of coolers: monoblock coolers and "separate" coolers.

Dans un refroidisseur monobloc, l'oscillateur et le doigt froid constituent une seule pièce. Le mouvement du régénérateur est généralement assuré, dans le cas d'un oscillateur rotatif, par le piston de l'oscillateur. Cette configuration est très compacte, elle limite les pertes de charge entre l'oscillateur et le doigt froid. Mais les vibrations induites par l'oscillateur se transmettent au dispositif à refroidir.In a monobloc cooler, the oscillator and the cold finger are one piece. The movement of regenerator is generally provided, in the case of a rotary oscillator, by the oscillator piston. This configuration is very compact, it limits the pressure drops between the oscillator and the cold finger. However, the vibrations induced by the oscillator are transmitted to the device to be cooled.

Dans un refroidisseur "séparé", l'oscillateur et le doigt froid sont éloignés mais reliés par un conduit pneumatique qui assure le transfert de l'onde de pression entre l'oscillateur et le doigt froid. Le mouvement du régénérateur peut être assuré par un moteur spécifique ou par les effets pneumatiques générés par l'onde de pression. La première configuration est généralement utilisée dans des applications spatiales. Ces deux configurations permettent d'éloigner l'oscillateur et l'équipement à refroidir ce qui facilite l'intégration du refroidisseur dans l'environnement du dispositif à refroidir. De plus, ces deux configurations permettent de réduire considérablement les vibrations au niveau du dispositif à refroidir.In a "separate" cooler, the oscillator and the cold finger are separated but connected by a pneumatic conduit which ensures the transfer of the pressure wave between the oscillator and the cold finger. The movement of the regenerator can be ensured by a specific motor or by the pneumatic effects generated by the pressure wave. The first configuration is generally used in space applications. These two configurations make it possible to separate the oscillator and the equipment to be cooled, which facilitates the integration of the cooler into the environment of the device to be cooled. In addition, these two configurations make it possible to considerably reduce the vibrations at the level of the device to be cooled.

Les refroidisseurs à régénérateur mobile ont un coût relativement élevé à cause des tolérances d'usinage requises pour réaliser le régénérateur et le doigt froid qui sont en mouvement l'un par rapport à l'autre.Mobile regenerator coolers have a relatively high cost because of the machining tolerances required to produce the regenerator and the cold finger which are in movement with respect to each other.

Des refroidisseurs à doigt froid du type tube pulsé sont aussi connus. Le doigt froid au lieu de contenir un régénérateur mobile contient un régénérateur fixe et un tube pulsé.Pulsed tube type cold finger coolers are also known. The cold finger instead of containing a mobile regenerator contains a fixed regenerator and a pulsed tube.

Les avantages de ce genre de refroidisseurs sont nombreux. La durée de vie du doigt froid est quasi-illimitée car la suppression du mouvement réduit l'usure. Les vibrations induites dans le doigt froid sont beaucoup plus faibles que celles induites dans les doigts froids à régénérateur mobile. Les coûts sont aussi beaucoup plus faibles du fait d'un fonctionnement moins sensible aux tolérances géométriques de fabrication. Le régénérateur fixe permet de réduire les pertes de rendement liées à l'effet navette et aux fuites de fluide entre la paroi extérieure du doigt froid et le régénérateur. Ces refroidisseurs, dans la mesure où ils utilisent un tube pulsé à double orifice, ont un rendement sensiblement équivalent à celui d'un refroidisseur à doigt froid muni d'un régénérateur mobile. Un refroidisseur à tube pulsé à double orifice est décrit ultérieurement à la figure 1.The advantages of this kind of coolers are numerous. The lifespan of the cold finger is almost unlimited because the elimination of movement reduces wear. The vibrations induced in the cold finger are much lower than those induced in the cold fingers with mobile regenerator. The costs are also much lower due to an operation less sensitive to geometric manufacturing tolerances. Fixed regenerator reduces losses efficiency linked to the shuttle effect and fluid leaks between the outer wall of the cold finger and the regenerator. These coolers, insofar as they use a pulsed tube with double orifice, have an efficiency substantially equivalent to that of a cold finger cooler provided with a mobile regenerator. A double orifice pulsed tube cooler is described later in Figure 1.

L'inconvénient majeur de ce type de refroidisseur est lié à la forme de U du doigt froid. L'une des branches du U est réalisée par le régénérateur et l'autre par le tube pulsé. La base du U qui est aussi l'extrémité libre du doigt froid est formée d'une pièce d'extrémité solidaire d'un côté du régénérateur et de l'autre du tube pulsé.The major drawback of this type of cooler is linked to the U shape of the cold finger. One of the branches of the U is produced by the regenerator and the other by the pulsed tube. The base of the U which is also the free end of the cold finger is formed of an end piece integral with one side of the regenerator and the other of the pulsed tube.

Ce doigt froid impose un cryostat spécifique et donc empêche son implantation dans un cryostat prévu pour un doigt froid à régénérateur mobile ou de type Joule-Thomson. La maintenance "sur le terrain" du doigt froid à tube pulsé n'est pas possible alors que l'intervention sur un doigt froid à régénérateur mobile est aisée. En effet, il faudrait casser le vide du cryostat pour démonter le tube pulsé ou le régénérateur.This cold finger imposes a specific cryostat and therefore prevents its implantation in a cryostat intended for a cold finger with mobile regenerator or of the Joule-Thomson type. Maintenance "on the ground" of the cold finger with pulsed tube is not possible while intervention on a cold finger with mobile regenerator is easy. Indeed, it would be necessary to break the vacuum of the cryostat to dismantle the pulsed tube or the regenerator.

La présente invention vise à remédier à ces inconvénients. Elle propose un refroidisseur basé sur le cycle de Stirling, muni d'un doigt froid de type à tube pulsé. Ce refroidisseur peut être implanté dans un cryostat classique et il possède de bonnes performances thermodynamiques.The present invention aims to remedy these drawbacks. It offers a cooler based on the Stirling cycle, fitted with a cold finger of the pulsed tube type. This cooler can be installed in a conventional cryostat and it has good thermodynamic performance.

Plus précisément, le refroidisseur selon l'invention comporte des moyens pour générer une onde de pression dans un fluide et la transmettre à un doigt froid du type à tube pulsé. Le doigt froid comporte un régénérateur relié pneumatiquement au tube pulsé, ce régénérateur est tubulaire et est monté coaxialement autour du tube pulsé.More specifically, the cooler according to the invention comprises means for generating a pressure wave in a fluid and transmitting it to a cold finger of the pulsed tube type. The cold finger comprises a regenerator pneumatically connected to the pulsed tube, this regenerator is tubular and is mounted coaxially around the pulsed tube.

Le régénérateur peut, par exemple, être contenu entre un tube externe et un tube interne, le tube interne servant de tube pulsé. Dans une variante, le régénérateur peut être contenu dans un tube externe, la surface intérieure du régénérateur servant de tube pulsé.The regenerator can, for example, be contained between an outer tube and an inner tube, the inner tube serving as a pulsed tube. Alternatively, the regenerator can be contained in an outer tube, the inner surface of the regenerator serving as a pulsed tube.

On peut aussi envisager que lorsque le doigt froid est plongé dans un cryostat, le tube externe serve de paroi intérieure au cryostat. Cette configuration qui supprime la paroi intérieure du cryostat permet d'améliorer les performances du refroidissement en réduisant les pertes par conduction.It is also conceivable that when the cold finger is immersed in a cryostat, the external tube serves as an interior wall for the cryostat. This configuration, which removes the inner wall of the cryostat, improves cooling performance by reducing losses by conduction.

D'autres caractéristiques et avantages de l'invention apparaitront à la lecture de la description suivante, donnée à titre d'exemples et illustrée par les figures annexées qui représentent:

  • figure 1: un refroidisseur connu, muni d'un doigt froid de type tube pulsé;
  • figure 2: un refroidisseur selon l'invention;
  • figure 3: des courbes des températures du tube pulsé et du fluide qu'il contient en fonction de la position le long du tube;
  • figures 4 à 7: quatre variantes d'un refroidisseur selon l'invention.
Other characteristics and advantages of the invention will appear on reading the following description, given by way of examples and illustrated by the appended figures which represent:
  • Figure 1: a known cooler, equipped with a cold finger of the pulsed tube type;
  • Figure 2: a cooler according to the invention;
  • FIG. 3: curves of the temperatures of the pulsed tube and of the fluid which it contains as a function of the position along the tube;
  • Figures 4 to 7: four variants of a cooler according to the invention.

Sur ces figures les mêmes éléments portent les mêmes références. Dans un souci de clarté, les côtes ne sont pas respectées.In these figures the same elements bear the same references. For the sake of clarity, the ribs are not respected.

La figure 1 représente un refroidisseur basé sur le cycle de Stirling muni d'un doigt froid 1 de type tube pulsé 5, selon l'art connu. Le doigt froid 1 est relié à un oscillateur 2 de pression à travers une embase 3. L'embase 3 assure l'interface mécanique et l'étanchéité entre le doigt froid 1 et un cryostat dans lequel on plonge généralement le doigt froid 1. L'embase 3 forme la base du doigt froid 1. Le cryostat n'est pas représenté pour des raisons de clarté.FIG. 1 represents a cooler based on the Stirling cycle provided with a cold finger 1 of the pulsed tube type 5, according to known art. The cold finger 1 is connected to a pressure oscillator 2 through a base 3. The base 3 provides the mechanical interface and the seal between the cold finger 1 and a cryostat in which the cold finger 1 is generally immersed. 'base 3 forms the base of the cold finger 1. The cryostat is not shown for reasons of clarity.

L'oscillateur 2 de pression génère une onde de pression dans un fluide et le fluide est successivement comprimé et détendu.The pressure oscillator 2 generates a pressure wave in a fluid and the fluid is successively compressed and expanded.

Le doigt froid 1 comporte un régénérateur 4 fixe contenu dans un tube 7 et un tube pulsé 5 qui forment les deux branches d'un U. Le régénérateur 4 a la forme d'un cylindre plein. La base du U est réalisée par une pièce d'extrémité 6 froide qui relie pneumatiquement le régénérateur 4 et le tube pulsé 5.The cold finger 1 comprises a fixed regenerator 4 contained in a tube 7 and a pulsed tube 5 which form the two branches of a U. The regenerator 4 has the shape of a full cylinder. The base of the U is produced by a cold end piece 6 which pneumatically connects the regenerator 4 and the pulsed tube 5.

Le tube 7 contenant le régénérateur a une extrémité chaude fixée à l'embase 3 et une extrémité froide fixée à la pièce d'extrémité 6. La pièce d'extrémité 6 constitue l'extrémité libre du doigt froid 1. C'est le point le plus froid du refroidisseur. Elle sert aussi à transmettre au dispositif à refroidir, placé à proximité, les frigories rendues disponibles par la détente du fluide.The tube 7 containing the regenerator has a hot end fixed to the base 3 and a cold end fixed to the end piece 6. The end piece 6 constitutes the free end of the cold finger 1. This is the point the cooler the cooler. It also serves to transmit to the device to be cooled, placed nearby, the frigories made available by the expansion of the fluid.

Le régénérateur 4 fixe fonctionne de la même façon qu'un régénérateur mobile. Il est réalisé dans un matériau poreux perméable au fluide. Le régénérateur 4 est relié pneumatiquement à l'oscillateur 2.The fixed regenerator 4 operates in the same way as a mobile regenerator. It is made of a porous material permeable to fluid. The regenerator 4 is pneumatically connected to the oscillator 2.

Le régénérateur a pour fonction de capter du froid au fluide lorsque ce dernier est aspiré par l'oscillateur 2 durant la phase de détente et d'évacuer de la chaleur vers ce fluide lorsqu'il est refoulé durant la phase de compression.The function of the regenerator is to capture cold from the fluid when the latter is sucked in by the oscillator 2 during the expansion phase and to evacuate heat to this fluid when it is discharged during the compression phase.

Le tube pulsé 5 est simplement constitué d'un tube sensiblement parallèle au tube 7 contenant le régénérateur 4. Il est solidaire à une extrémité froide de la pièce d'extrémité 6 et à l'autre extrémité chaude de l'embase 3.The pulsed tube 5 simply consists of a tube substantially parallel to the tube 7 containing the regenerator 4. It is integral with one cold end of the end piece 6 and the other hot end of the base 3.

Un circuit pneumatique 8 sert à relier l'oscillateur 2 de pression au régénérateur 4 et au tube pulsé 5. Un réservoir tampon 9 est aussi prévu et relié au circuit pneumatique 8. Il a un volume suffisant pour que le fluide qu'il contient reste à une pression sensiblement constante quelle que soit la phase de l'oscillateur de pression 2. Lorsque l'oscillateur aspire le fluide, le fluide du réservoir tampon 9 alimente le tube pulsé 5 et lorsque l'oscillateur 2 refoule, le fluide refoulé remplit le réservoir tampon 9.A pneumatic circuit 8 is used to connect the pressure oscillator 2 to the regenerator 4 and to the pulsed tube 5. A buffer tank 9 is also provided and connected to the pneumatic circuit 8. It has a sufficient volume so that the fluid which it contains remains at a substantially constant pressure whatever the phase of the pressure oscillator 2. When the oscillator sucks in the fluid, the fluid in the buffer tank 9 feeds the pulsed tube 5 and when the oscillator 2 discharges, the discharged fluid fills the buffer tank 9.

Le circuit pneumatique comporte un premier conduit 8 reliant le régénérateur 4 à l'oscillateur 2, un deuxième conduit 82 reliant l'extrémité chaude du tube pulsé 5 au réservoir tampon 9 et un troisième conduit 83 reliant l'extrémité chaude du tube pulsé à l'oscillateur de pression 2. Le tube pulsé est relié à la fois à l'oscillateur et au réservoir tampon.The pneumatic circuit comprises a first conduit 8 connecting the regenerator 4 to the oscillator 2, a second conduit 82 connecting the hot end of the pulsed tube 5 to the buffer tank 9 and a third conduit 83 connecting the hot end of the pulsed tube to the pressure oscillator 2. The pulsed tube is connected both to the oscillator and to the buffer tank.

Le fluide traverse un échangeur de chaleur 10 chaud entre l'extrémité chaude du tube pulsé 5 et l'oscillateur 2 et/ou le réservoir tampon 9. Cet échangeur chaud 10 peut être logé dans l'embase 3.The fluid passes through a hot heat exchanger 10 between the hot end of the pulsed tube 5 and the oscillator 2 and / or the buffer tank 9. This hot exchanger 10 can be housed in the base 3.

Sur la figure 1, le troisième conduit 83 est disposé entre le premier conduit 81 et le deuxième conduit 82 et il atteint le deuxième conduit 82 entre le réservoir tampon 9 et l'échangeur de chaleur chaud 10.In FIG. 1, the third conduit 83 is disposed between the first conduit 81 and the second conduit 82 and it reaches the second conduit 82 between the buffer tank 9 and the hot heat exchanger 10.

L'échangeur de chaleur chaud 10 assure le captage de la chaleur de compression du fluide sortant du tube pulsé et son évacuation, via l'embase 3, vers l'extérieur du refroidisseur.The hot heat exchanger 10 collects the heat of compression of the fluid leaving the pulsed tube and its evacuation, via the base 3, to the outside of the cooler.

Le mouvement du fluide dans le doigt froid est déphasé par rapport à l'onde de pression générée par l'oscillateur 2. Le déphasage et les débits aux extrémités chaudes du tube pulsé 5 et du tube 7 contenant le régénérateur 4 sont fonction de l'impédance pneumatique des conduits 81, 82 et 83 et du volume du réservoir tampon 9. Le réglage de l'impédance pneumatique des conduits peut se faire par un choix adéquat de leur section, de leur longueur. Les conduits peuvent aussi comporter de simples pincements ou des orifices 11 calibrés comme sur la figure 1 ou même des vannes.The movement of the fluid in the cold finger is out of phase with respect to the pressure wave generated by the oscillator 2. The phase shift and the flow rates at the hot ends of the pulsed tube 5 and of the tube 7 containing the regenerator 4 are a function of the pneumatic impedance of the conduits 81, 82 and 83 and of the volume of the buffer tank 9. The pneumatic impedance of the conduits can be adjusted by an appropriate choice of their section, their length. The conduits can also include simple pinches or orifices 11 calibrated as in FIG. 1 or even valves.

Le comportement du fluide dans le tube pulsé est le suivant : considérons un volume A de fluide qui transite entre l'extrémité froide du tube pulsé 5 et la pièce d'extrémité 6. Du fait du déphasage du mouvement du fluide dans le doigt froid avec les phases de détente et de compression de l'oscillateur 2, ce fluide lorsqu'il se détend transite vers la pièce d'extrémité 6 en la refroidissant et lorsqu'il se comprime, pénètre dans le tube pulsé 5 où il s'échauffe de manière quasi-adiabatique.The behavior of the fluid in the pulsed tube is as follows: let us consider a volume A of fluid which transits between the cold end of the pulsed tube 5 and the end piece 6. Due to the phase shift of the movement of the fluid in the cold finger with the expansion and compression phases of the oscillator 2, this fluid when it relaxes passes to the end piece 6 while cooling it and when it compresses, enters the pulsed tube 5 where it heats up almost adiabatic way.

Considérons maintenant un volume B de fluide qui transite entre l'extrémité chaude du tube pulsé 5 et l'échangeur chaud 10. Du fait du déphasage du mouvement du fluide dans le doigt froid avec les phases de détente et de compression de l'oscillateur 2, ce fluide lorsqu'il se comprime transite vers l'échangeur chaud en lui cèdant sa chaleur et lorsqu'il se détend pénètre dans le tube pulsé où il se refroidit de manière quasi-adiabatique.Let us now consider a volume B of fluid which passes between the hot end of the pulsed tube 5 and the exchanger hot 10. Due to the phase shift of the movement of the fluid in the cold finger with the expansion and compression phases of the oscillator 2, this fluid when it compresses transits towards the hot exchanger by giving it its heat and when it relaxes enters the pulsed tube where it cools in an almost adiabatic way.

Considérons un volume C de fluide qui reste en permanence dans le tube pulsé 5. Ce volume joue un rôle de volume tampon entre les deux volumes précédents. Il a le même effet navette que le déplaceur mobile des refroidisseurs classiques. Il subit des cycles de compression et de détente adiabatiques et réversibles. Il participe aux échanges thermiques essentiellement via la paroi du tube pulsé 5.Let us consider a volume C of fluid which remains permanently in the pulsed tube 5. This volume plays a role of buffer volume between the two preceding volumes. It has the same shuttle effect as the mobile displacer of conventional coolers. It undergoes adiabatic and reversible compression and relaxation cycles. It takes part in heat exchanges essentially via the wall of the pulsed tube 5.

La figure 2 représente schématiquement un refroidisseur selon l'invention. Ce refroidisseur est comparable à celui de la figure 1. La principale différence se situe au niveau du doigt froid 21 qui au lieu de comporter un régénérateur et un tube pulsé configurés en U comporte un régénérateur 24 tubulaire monté coaxialement autour du tube pulsé 25. Le doigt froid 21 est toujours relié à un oscillateur 2 à travers une embase 3. L'embase 3 joue le même rôle que sur la figure 1.FIG. 2 schematically represents a cooler according to the invention. This cooler is comparable to that of FIG. 1. The main difference is at the level of the cold finger 21 which, instead of comprising a regenerator and a pulsed tube configured in U, comprises a tubular regenerator 24 mounted coaxially around the pulsed tube 25. The cold finger 21 is always connected to an oscillator 2 through a base 3. The base 3 plays the same role as in FIG. 1.

L'extrémité libre du doigt froid se termine toujours par une pièce d'extrémité 26. C'est toujours la partie la plus froide du refroidisseur.The free end of the cold finger always ends with an end piece 26. It is always the coldest part of the cooler.

Le régénérateur 24 joue le même rôle que dans l'art connu. Au lieu d'avoir la forme d'un cylindre plein il a maintenant la forme d'un tube. Le régénérateur 24 est contenu entre un tube externe 27 et un tube interne 28. Le tube externe 27 cylindrique a une extrémité chaude fixée de manière étanche à l'embase 3 et une extrémité froide fixée de manière étanche à la pièce d'extrémité 26. Il forme la surface extérieure du doigt froid 21. Ce tube externe 27 a de préférence une épaisseur aussi fine que possible pour limiter les entrées thermiques le long du doigt froid. Il est réalisé, de préférence, dans un matériau ayant une conductivité thermique aussi faible que possible, par exemple de l'acier inoxydable. Ce tube externe 27 ainsi que ses fixations à l'embase 3 et à la pièce d'extrémité 26 doivent assurer l'étanchéité de l'intérieur du doigt froid vis-à-vis du milieu extérieur. Le doigt froid est généralement plongé dans un cryostat soumis au vide. Ce cryostat est représenté avec la référence 30 sur la figure 4 sous la forme d'un vase de Dewar.The regenerator 24 plays the same role as in the known art. Instead of having the shape of a full cylinder it now has the shape of a tube. The regenerator 24 is contained between an outer tube 27 and an inner tube 28. The cylindrical outer tube 27 has a hot end tightly fixed to the base 3 and a cold end tightly fixed to the end piece 26. It forms the outer surface of the cold finger 21. This outer tube 27 preferably has a thickness as thin as possible to limit thermal entry along the cold finger. It is preferably carried out in a material with as low a thermal conductivity as possible, for example stainless steel. This external tube 27 as well as its attachments to the base 3 and to the end piece 26 must seal the interior of the cold finger vis-à-vis the external environment. The cold finger is generally immersed in a cryostat subjected to vacuum. This cryostat is represented with the reference 30 in FIG. 4 in the form of a Dewar vase.

Le tube interne 28 sert à la fois de tube pulsé et de paroi intérieure au régénérateur 24 tubulaire. Il est disposé coaxialement dans le tube externe 27 et a une extrémité chaude fixée à l'embase 3. Son autre extrémité qui est froide débouche dans la pièce d'extrémité 26. Ce tube interne 28 n'est pas soumis comme le tube externe 27 à des différences de pression importantes. Il n'est pas nécessaire qu'il soit strictement étanche comme le tube externe. Il évite un passage direct du fluide du régénérateur 24 au tube pulsé 25 sans passer par la pièce d'extrémité 26. La conception de ce tube interne 28 vis-à-vis du choix du matériau le constituant, de son mode de fixation, et son épaisseur pourra être plus facilement optimisée. On peut même envisager de supprimer physiquement le tube interne 28 si la surface interne du régénérateur 24 est étanche. Dans ce cas, c'est la surface intérieure du régénérateur qui sert de tube pulsé.The inner tube 28 serves both as a pulsed tube and as an inner wall to the tubular regenerator 24. It is arranged coaxially in the external tube 27 and has a hot end fixed to the base 3. Its other end which is cold opens into the end piece 26. This internal tube 28 is not subjected like the external tube 27 to significant pressure differences. It does not have to be tightly sealed like the outer tube. It avoids direct passage of the fluid from the regenerator 24 to the pulsed tube 25 without passing through the end piece 26. The design of this internal tube 28 with respect to the choice of the constituent material, its method of fixing, and its thickness can be more easily optimized. One can even consider physically removing the inner tube 28 if the inner surface of the regenerator 24 is sealed. In this case, it is the interior surface of the regenerator which serves as a pulsed tube.

La pièce d'extrémité 26 ressemble aux pièces d'extrémité des doigts froids à régénérateur mobile. Le régénérateur et le tube pulsé communiquent pneumatiquement grâce à elle. Pour faciliter l'échange thermique entre le fluide et le dispositif à refroidir disposé à proximité de la pièce d'extrémité 26, l'épaisseur de la pièce d'extrémité 26 sera la plus faible possible. Elle sera réalisée dans un matériau ayant une conductivité thermique aussi élevée que possible : du cuivre par exemple. On peut envisager que la pièce d'extrémité contienne un échangeur froid 29 formé par exemple de grilles de cuivre brasées à leur périphérie. Cet échangeur froid 29 améliore l'échange thermique entre le fluide et la pièce d'extrémité 26.The end piece 26 resembles the end pieces of the cold fingers with mobile regenerator. The regenerator and the pulsed tube communicate pneumatically thanks to it. To facilitate the heat exchange between the fluid and the device to be cooled disposed near the end piece 26, the thickness of the end piece 26 will be as small as possible. It will be made of a material having as high a thermal conductivity as possible: copper for example. It is conceivable that the end piece contains a cold exchanger 29 formed for example of copper grids brazed at their periphery. This cold exchanger 29 improves the heat exchange between the fluid and the end piece 26.

Le matériau de la pièce d'extrémité 26 aura, de préférence, un coefficient de dilatation aussi faible que possible lorsque le doigt froid 21 sera employé pour refroidir un dispositif posé directement sur la pièce d'extrémité 26 (technique connue sous la dénomination anglo-saxonne d' Integrated Dewar Cooler Assembly).The material of the end piece 26 will preferably have a coefficient of expansion as low as possible when the cold finger 21 is used to cool a device placed directly on the end piece 26 (technique known by the English name Integrated Dewar Cooler Assembly).

La pièce d'extrémité 26 pourra, par exemple, être pourvue d'un dispositif tranquilliseur pour assurer un niveau de turbulences le plus faible possible dans le tube pulsé 25. Il est en effet souhaitable de maintenir un gradient thermique important entre les deux extrémités chaudes et froides du tube pulsé. Ce dispositif transquilliseur peut être réalisé par une pièce en nid d'abeille ou par l'échangeur froid 29. Les autres éléments du refroidisseur à savoir l'oscillateur 2, le circuit pneumatique 8, le réservoir tampon 9 et l'échangeur chaud 10 sont comparables à ceux de la figure 1.The end piece 26 may, for example, be provided with a tranquilizer device to ensure the lowest possible level of turbulence in the pulsed tube 25. It is indeed desirable to maintain a large thermal gradient between the two hot ends and cold from the pulsed tube. This transquilliser device can be produced by a honeycomb part or by the cold exchanger 29. The other elements of the cooler, namely the oscillator 2, the pneumatic circuit 8, the buffer tank 9 and the hot exchanger 10 are comparable to those in Figure 1.

L'échangeur chaud 10 s'il est configuré avec des grilles ou un matériau en nid d'abeille a aussi un role de tranquilliseur .The hot heat exchanger 10 if it is configured with grids or a honeycomb material also has a role of tranquilizer.

Le réglage optimal du déphasage et de l'amplitude des débits de fluide dans le régénérateur 24 et le tube pulsé 25 dépendra du volume du réservoir tampon 9 et des caractéristiques des conduits 81, 82, 83 comme précédemment.The optimal adjustment of the phase shift and the amplitude of the fluid flow rates in the regenerator 24 and the pulsed tube 25 will depend on the volume of the buffer tank 9 and on the characteristics of the conduits 81, 82, 83 as before.

Le fait d'avoir placé le tube pulsé 25 à l'extérieur du régénérateur 24 permet de réaliser un refroidisseur dont le rendement est du même ordre que celui du refroidisseur de la figure 1. Lorsqu'on a analysé le comportement du fluide dans le tube pulsé, on a vu que le fluide qui reste en permanence dans le tube pulsé participe aux échanges thermiques essentiellement via la paroi du tube pulsé. L'exemple numérique qui suit, illustré par la figure 3, montre qu'on a intérêt à limiter au maximum cet échange thermique car il a une action néfaste sur le rendement du refroidisseur.The fact of having placed the pulsed tube 25 outside of the regenerator 24 makes it possible to produce a cooler whose performance is of the same order as that of the cooler of FIG. 1. When the behavior of the fluid in the tube has been analyzed pulsed, we have seen that the fluid which remains permanently in the pulsed tube participates in heat exchanges essentially via the wall of the pulsed tube. The following numerical example, illustrated by FIG. 3, shows that it is advantageous to limit this heat exchange as much as possible since it has a harmful effect on the efficiency of the cooler.

On suppose que le tube pulsé a une longueur de 70 mm et qu'en fonctionnement ses températures extrêmes sont de 80° K à l'extrémité froide et 300° K à l'extrémité chaude. On suppose que le gradiant thermique est linéaire dans la paroi du tube pulsé, que la pression moyenne dans le tube pulsé est de 35.10⁵Pa et qu'elle varie de plus ou moins 10⁶Pa, à cause de l'onde de pression. On considère une tranche fine de fluide située au milieu du tube pulsé. Lors des cycles de compression et de détente, son déplacement entre la position a1 et la position a2 aura une amplitude de plus au moins 10 mm par rapport à sa position a0 au repos. Ces données physiques sont typiques d'un refroidisseur de détecteur infrarouge.It is assumed that the pulsed tube has a length of 70 mm and that in operation its extreme temperatures are 80 ° K at the cold end and 300 ° K at the hot end. It is assumed that the thermal gradient is linear in the wall of the pulsed tube, that the average pressure in the pulsed tube is 35.10⁵Pa and that it varies more or less 10⁶Pa, because of the pressure wave. We consider a thin slice of fluid located in the middle of the pulsed tube. During the compression and expansion cycles, its displacement between the position a1 and the position a2 will have an amplitude of at least 10 mm relative to its position a0 at rest. This physical data is typical of an infrared detector cooler.

La tranche de fluide aura une température moyenne de 190°K mais au cours des cycles de détente et de compression, elle verra sa température osciller entre 166°K et 210°K (courbe C1). Cette tranche de fluide sera en vis-à-vis avec un tronçon de tube pulsé dont les températures seront comprises entre 158°K et 221°K (courbe C2) à cause du gradient thermique linéaire .The slice of fluid will have an average temperature of 190 ° K but during the expansion and compression cycles, it will see its temperature oscillate between 166 ° K and 210 ° K (curve C1). This slice of fluid will be vis-à-vis with a section of pulsed tube whose temperatures will be between 158 ° K and 221 ° K (curve C2) because of the linear thermal gradient.

En phase de détente, le fluide sera en contact avec une portion de tube pulsé plus froide que lui et aura tendance à lui céder de la chaleur. De manière symétrique, en phase de compression, le fluide sera en contact avec une portion de tube pulsé plus chaude que lui et aura tendance à en extraire de la chaleur. Cet effet de pompage de chaleur de l'extrémité chaude du tube pulsé vers l'extrémité froide est néfaste pour le rendement du refroidisseur. Ces échanges thermiques avec les parois ne concernent qu'une partie du fluide : la couche limite thermique qui est suffisamment proche de la paroi pour avoir le temps d'échanger, principalement par conduction gazeuse, de la chaleur durant un cycle de compression-détente. Un refroidisseur selon l'invention permet de réduire les échanges entre le fluide et la paroi du tube pulsé en plaçant le tube pulsé à l'intérieur du régénérateur et non autour.In the expansion phase, the fluid will be in contact with a portion of the pulsed tube cooler than it and will tend to give it heat. Symmetrically, in the compression phase, the fluid will be in contact with a portion of the pulsed tube hotter than it and will tend to extract heat from it. This heat pumping effect from the hot end of the pulsed tube to the cold end is detrimental to the performance of the cooler. These heat exchanges with the walls concern only part of the fluid: the thermal boundary layer which is close enough to the wall to have time to exchange, mainly by gas conduction, heat during a compression-expansion cycle. A cooler according to the invention makes it possible to reduce the exchanges between the fluid and the wall of the pulsed tube by placing the pulsed tube inside the regenerator and not around it.

Si le doigt froid est formé de deux tubes (d'épaisseur nulle pour simplifier) coaxiaux de diamètres 5mm et 3,5mm, dans le cas d'une épaisseur de couche limite thermique de 0,2 mm, on peut estimer que seulement 20 % de fluide participe à l'échange thermique avec la paroi du tube pulsé, si le tube pulsé est placé à l'intérieur du régénérateur, alors que plus de 50 % de fluide participe à l'échange thermique avec les parois externes et internes du tube pulsé, si le régénérateur est placé à l'intérieur du tube pulsé.If the cold finger is formed of two coaxial tubes (of zero thickness for simplicity) of diameters 5mm and 3.5mm, in the case of a thickness of thermal boundary layer of 0.2 mm, it can be estimated that only 20% of fluid participates in the heat exchange with the wall of the pulsed tube, if the pulsed tube is placed inside the regenerator, while more than 50% of fluid participates in the heat exchange with the external and internal walls of the tube pulsed, if the regenerator is placed inside the pulsed tube.

Les figures 4 à 7 représentent diverses variantes d'un refroidisseur selon l'invention. On se réfère à la figure 4.Figures 4 to 7 show various variants of a cooler according to the invention. We refer to figure 4.

Le doigt froid est plongé dans un cryostat tel qu'un vase de Dewar 30 comportant deux enceintes 31, 32 insérées l'une dans l'autre et séparées par du vide. L'enceinte interne 32 a la forme d'un puits. Le dispositif à refroidir référencé 33 est disposé entre l'enceinte externe 31 et l'enceinte interne 32. Il est fixé au au fond du puits. Un coupleur thermique 34 est inséré entre l'extrémité libre du doigt froid 21 et le fond du puits pour optimiser le refroidissement du dispositif à refroidir 33.The cold finger is immersed in a cryostat such as a Dewar vessel 30 comprising two chambers 31, 32 inserted one inside the other and separated by a vacuum. The internal enclosure 32 has the shape of a well. The cooling device referenced 33 is disposed between the external enclosure 31 and the internal enclosure 32. It is fixed to the bottom of the well. A thermal coupler 34 is inserted between the free end of the cold finger 21 and the bottom of the well to optimize the cooling of the device to be cooled 33.

L'oscillateur 2 de pression est rotatif. Le réservoir tampon est constitué par le carter 35 de l'oscillateur ce qui permet de gagner de la place.The pressure oscillator 2 is rotary. The buffer tank is constituted by the casing 35 of the oscillator, which saves space.

Le deuxième conduit 82 et le troisième conduit 83 comportent chacun une vanne 36 au lieu d'un orifice calibré et, de plus, le deuxième conduit 82 est muni d'un pincement 37 entre la vanne et l'échangeur chaud 10.The second conduit 82 and the third conduit 83 each comprise a valve 36 instead of a calibrated orifice and, moreover, the second conduit 82 is provided with a pinch 37 between the valve and the hot exchanger 10.

On se réfère maintenant à la figure 5. Le doigt froid et l'embase sont représentés par un seul bloc 50 pour simplifier. Maintenant l'oscillateur de pression 51 est un oscillateur linéaire résonnant. Le réservoir tampon 52 est pourvu d'un dispositif de chauffage 54. La température du fluide dans le réservoir tampon 52 est réglable de manière à pouvoir ajuster la pression moyenne dans le refroidisseur et à pouvoir ajuster la fréquence de résonance du refroidisseur. Ceci est particulièrement intéressant dans le cas où le refroidisseur est utilisé dans un satellite où l'on recherche une fréquence réglable pour éviter d'exciter la plateforme ou des instruments à proximité du refroidisseur. Dans cette configuration, l'échangeur chaud est constitué par un dispositif à ailettes 55 ou équivalent. Ce dispositif 55 est disposé sur le deuxième conduit 82 reliant le tube pulsé au réservoir tampon 52. Les autres conduits 81, 83 et le réservoir 52 pourraient aussi participer à l'évacuation de la chaleur de compression du fluide. A cet effet, on les équiperait de dispositifs, à ailettes par exemple, améliorant la dissipation de cette chaleur vers l'extérieur.Reference is now made to FIG. 5. The cold finger and the base are represented by a single block 50 for simplicity. Now the pressure oscillator 51 is a resonant linear oscillator. The buffer tank 52 is provided with a heating device 54. The temperature of the fluid in the buffer tank 52 is adjustable so as to be able to adjust the average pressure in the cooler and to be able to adjust the resonant frequency of the cooler. this is particularly advantageous in the case where the cooler is used in a satellite where an adjustable frequency is sought in order to avoid exciting the platform or instruments near the cooler. In this configuration, the hot exchanger is constituted by a fin device 55 or equivalent. This device 55 is arranged on the second conduit 82 connecting the pulsed tube to the buffer tank 52. The other conduits 81, 83 and the reservoir 52 could also participate in the evacuation of the heat of compression of the fluid. To this end, they would be fitted with devices, with fins for example, improving the dissipation of this heat to the outside.

Le réservoir tampon 52 est pourvu d'un dispositif tranquilliseur 56 pour assurer un niveau de turbulences aussi bas que possible dans le tube pulsé. Ce dispositif tranquilliseur 56 peut être de même nature que celui décrit dans la pièce d'extrémité 26 de la figure 2.The buffer tank 52 is provided with a tranquilizer device 56 to ensure a level of turbulence as low as possible in the pulsed tube. This tranquilizer device 56 can be of the same nature as that described in the end piece 26 of FIG. 2.

On se réfère à la figure 6. Le doigt froid 60, plongé dans un cryostat 61, et l'oscillateur de pression 68 rotatif forment un refroidisseur monobloc. Le carter 69 du compresseur constitue le réservoir tampon. Le doigt froid 60 comporte un tube externe 62, un régénérateur tubulaire 63 et un tube pulsé 66. Dans cet exemple, le tube externe 62 sert de paroi intérieure au cryostat. La surface intérieure du régénérateur tubulaire sert de tube pulsé 66. La suppression de la paroi intérieure du cryostat peut bien sur être utilisée dans d'autres configurations .Reference is made to FIG. 6. The cold finger 60, immersed in a cryostat 61, and the rotary pressure oscillator 68 form a monobloc cooler. The compressor casing 69 constitutes the buffer tank. The cold finger 60 comprises an external tube 62, a tubular regenerator 63 and a pulsed tube 66. In this example, the external tube 62 serves as an interior wall for the cryostat. The inner surface of the tubular regenerator serves as a pulsed tube 66. The removal of the inner wall of the cryostat can of course be used in other configurations.

Le dispositif à refroidir 65 est directement fixé sur la pièce d'extrémité 64 qui relie le tube pulsé et le régénérateur. Le refroidissement est amélioré par rapport à la configuration où le tube externe et la paroi intérieure du cryostat sont distincts. Sur cette figure, on a placé un dispositif de refroidissement 67 à circulation de fluide autour de l'échangeur chaud 10. Ce dispositif de refroidissement est de préférence utilisé lorsque le tube pulsé est soumis à des puissances importantes, par exemple supérieures à quelques watts. Au lieu d'utiliser un dispositif de refroidissement à circulation de fluide on aurait pu utiliser un dispositif de refroidissement à convection naturelle ou forcée avec de l'air par exemple. La configuration représentée est particulièrement compacte, elle limite au maximum les pertes de charge entre l'oscillateur 68 et le doigt froid 60.The cooling device 65 is directly fixed to the end piece 64 which connects the pulsed tube and the regenerator. Cooling is improved compared to the configuration where the outer tube and the inner wall of the cryostat are separate. In this figure, a cooling device 67 with fluid circulation has been placed around the hot exchanger 10. This cooling device is preferably used when the pulsed tube is subjected to significant powers, for example greater than a few watts. Instead of using a fluid circulation cooling device, one could have used a cooling device with natural or forced convection with air for example. The configuration shown is particularly compact, it minimizes the pressure drops between the oscillator 68 and the cold finger 60.

On se réfère à la figure 7. Le refroidisseur comporte maintenant plusieurs oscillateurs de pression 70, 71, 72 montés en parallèle. Un commutateur 73 ayant plusieurs voies d'entrée et une voie de sortie permet de relier le doigt froid à l'un des oscillateurs de pression 71. Avec un doigt froid sans pièce mobile, le seul élément présentant un risque de panne relativement élevé est l'oscillateur de pression qui lui a des pièces mobiles. La commutation d'un oscillateur de pression à un autre peut être commandée par l'utilisateur ou automatiquement lorsque le fonctionnement de l'oscillateur en service n'est plus normal. Cette commutation ne nécessite ni intervention, ni démontage sur le doigt froid et le cryostat, elle peut se réaliser de manière instantanée et à distance.Reference is made to FIG. 7. The cooler now comprises several pressure oscillators 70, 71, 72 mounted in parallel. A switch 73 having several input channels and an output channel makes it possible to connect the cold finger to one of the pressure oscillators 71. With a cold finger without moving part, the only element presenting a relatively high risk of failure is the pressure oscillator which has moving parts. The switching from one pressure oscillator to another can be controlled by the user or automatically when the operation of the oscillator in service is no longer normal. This switching does not require any intervention or disassembly on the cold finger and the cryostat, it can be carried out instantly and remotely.

Le refroidisseur selon l'invention peut refroidir tout dispositif notamment des capteurs ou détecteurs, des composants électroniques, des échantillons, etc ....The cooler according to the invention can cool any device, in particular sensors or detectors, electronic components, samples, etc.

Claims (14)

1- Refroidisseur basé sur le cycle de Stirling comportant des moyens (2, 8, 9) pour générer une onde de pression dans un fluide et la transmettre à un doigt froid (21) du type tube pulsé (25) comprenant un régénérateur (24) relié pneumatiquement au tube pulsé (25), caractérisé en ce que le régénérateur (24) est tubulaire et est monté coaxialement autour du tube pulsé (25). 1- Chiller based on the Stirling cycle comprising means (2, 8, 9) for generating a pressure wave in a fluid and transmitting it to a cold finger (21) of the pulsed tube type (25) comprising a regenerator (24 ) pneumatically connected to the pulsed tube (25), characterized in that the regenerator (24) is tubular and is mounted coaxially around the pulsed tube (25). 2- Refroidisseur selon la revendication 1, caractérisé en ce que le régénérateur (24) tubulaire est contenu entre un tube externe (27) et un tube interne (28), le tube interne (28) servant de tube pulsé. 2- Cooler according to claim 1, characterized in that the tubular regenerator (24) is contained between an external tube (27) and an internal tube (28), the internal tube (28) serving as a pulsed tube. 3- Refroidisseur selon la revendication 1, caractérisé en ce que le régénérateur (63) tubulaire est disposé dans un tube externe (62), la surface intérieure du régénérateur servant de tube pulsé. 3- cooler according to claim 1, characterized in that the tubular regenerator (63) is arranged in an external tube (62), the inner surface of the regenerator serving as a pulsed tube. 4- Refroidisseur selon l'une des revendications 2 ou 3, caractérisé en ce que le doigt froid est plongé dans un cryostat, le tube externe formant la paroi intérieure du cryostat. 4- cooler according to one of claims 2 or 3, characterized in that the cold finger is immersed in a cryostat, the outer tube forming the inner wall of the cryostat. 5- Refroidisseur selon l'une des revendications 1 à 4, caractérisé en ce que les moyens pour générer l'onde de pression et la transmettre au doigt froid comprennent un oscillateur (2) de pression, un réservoir tampon (9) et un circuit pneumatique (8) reliant l'oscillateur de pression (2) et le réservoir tampon (9) à la base du doigt froid (21). 5- Cooler according to one of claims 1 to 4, characterized in that the means for generating the pressure wave and transmitting it to the cold finger comprise a pressure oscillator (2), a buffer tank (9) and a circuit pneumatic (8) connecting the pressure oscillator (2) and the buffer tank (9) at the base of the cold finger (21). 6- Refroidisseur selon la revendication 5, caractérisé en ce que le circuit pneumatique (8) comporte un premier conduit (81) entre l'oscillateur (2) de pression et le régénérateur (24), un deuxième conduit (82) entre le réservoir tampon (9) et le tube pulsé (25) et un troisième conduit entre l'oscillateur (2) de pression et le tube pulsé (25). 6- Cooler according to claim 5, characterized in that the pneumatic circuit (8) comprises a first conduit (81) between the pressure oscillator (2) and the regenerator (24), a second conduit (82) between the tank buffer (9) and the pulsed tube (25) and a third conduit between the pressure oscillator (2) and the pulsed tube (25). 7- Refroidisseur selon l'une des revendications 5 ou 6, caratérisé en ce que l'oscillateur (2) de pression a un carter qui sert de réservoir tampon. 7- Cooler according to one of claims 5 or 6, characterized in that the pressure oscillator (2) has a housing which serves as a buffer tank. 8- Refroidisseur selon l'une des revendications 5 à 7, caractérisé en ce que le fluide traverse un échangeur chaud (10) entre l'oscillateur (2) de pression et/ou le réservoir tampon (9) et le tube pulsé (25). 8- Cooler according to one of claims 5 to 7, characterized in that the fluid passes through a hot exchanger (10) between the pressure oscillator (2) and / or the buffer tank (9) and the pulsed tube (25 ). 9- Refroidisseur selon l'une des revendications 1 à 8, caractérisé en ce que le fluide traverse un échangeur froid (29) entre le régénérateur (24) et le tube pulsé (25) au niveau de l'extrémité libre du doigt froid (21). 9- Cooler according to one of claims 1 to 8, characterized in that the fluid passes through a cold exchanger (29) between the regenerator (24) and the pulsed tube (25) at the free end of the cold finger ( 21). 10- Refroidisseur selon l'une des revendications 5 à 9, dans lequel l'oscillateur (51) de pression est un oscillateur linéaire résonant, caractérisé en ce qu'un dispositif (54) permet de modifier la température du fluide dans le réservoir tampon (52) et donc sa pression de manière à ce que le refroidisseur ait une fréquence de résonance ajustable. 10- Cooler according to one of claims 5 to 9, wherein the pressure oscillator (51) is a resonant linear oscillator, characterized in that a device (54) allows to modify the temperature of the fluid in the buffer tank (52) and therefore its pressure so that the cooler has an adjustable resonant frequency. 11- Refroidisseur selon l'une des revendications 5 à 10, dans lequel existe un déphasage de l'onde de pression entre l'oscillateur (2) de pression et le doigt froid (21), caractérisé en ce que le circuit pneumatique comporte des moyens pour régler le dit déphasage. 11- Cooler according to one of claims 5 to 10, in which there is a phase shift of the pressure wave between the pressure oscillator (2) and the cold finger (21), characterized in that the pneumatic circuit comprises means for adjusting said phase shift. 12- Refroidisseur selon la revendication 11, caratérisé en ce que les moyens pour régler le déphasage consistent à ajuster la longueur et/ou la section des conduits (81,82,83). 12- Chiller according to claim 11, characterized in that the means for adjusting the phase shift consist in adjusting the length and / or the section of the conduits (81,82,83). 13- Refroidisseur selon l'une des revendications 11 ou 12, caratérisé en ce qu'au moins un des conduits (81,82,83) comporte au moins un élément tel qu'un pincement de sa paroi, un orifice calibré, une vanne de manière à ajuster le déphasage de l'onde de pression. 13- Chiller according to one of claims 11 or 12, characterized in that at least one of the conduits (81,82,83) comprises at least one element such as a pinching of its wall, a calibrated orifice, a valve so as to adjust the phase shift of the pressure wave. 14- Refroidisseur selon l'une des revendications 5 à 13, caractérisé en ce qu'il comporte une pluralité d'oscillateurs (70, 71, 72) de pression montés en parallèle, un commutateur (73) permettant de relier le doigt froid à l'un des oscillateurs (71) de pression. 14- Chiller according to one of claims 5 to 13, characterized in that it comprises a plurality of oscillators (70, 71, 72) of pressure mounted in parallel, a switch (73) for connecting the cold finger to one of the pressure oscillators (71).
EP19940400432 1993-03-02 1994-03-01 Cooler with a cold finger of pulse tube type Expired - Lifetime EP0614059B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9302376 1993-03-02
FR9302376A FR2702269B1 (en) 1993-03-02 1993-03-02 Chiller fitted with a cold finger of the pulsed tube type.

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EP0614059A1 true EP0614059A1 (en) 1994-09-07
EP0614059B1 EP0614059B1 (en) 1998-12-16

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Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0717245A2 (en) * 1994-12-12 1996-06-19 Hughes Aircraft Company Concentric pulse tube expander
FR2736710A1 (en) * 1995-07-12 1997-01-17 Commissariat Energie Atomique REFRIGERATOR OR HEAT PUMP WITH PULSATION TUBE SUPPLIED BY A PRESSURE GENERATOR
FR2743871A1 (en) * 1996-01-24 1997-07-25 Hughes Aircraft Co DETERGENT FOR A PULSED TUBE CONCENTRIC COOLER, THIS COOLER AND COOLING SYSTEM USING THE SAME
EP0803687A1 (en) * 1996-04-23 1997-10-29 Cryotechnologies Cryostat for cryogenic refrigerator and refrigerators comprising such a cryostat
FR2760076A1 (en) * 1997-02-21 1998-08-28 Cryotechnologies Double effect pressure oscillator for electronic component cooling
WO1999020957A1 (en) * 1997-10-20 1999-04-29 Cornelis Maria De Blok Thermo-acoustic system
US5968637A (en) * 1996-05-07 1999-10-19 Thomson-Csf Use of nitride barrier to prevent the diffusion of silver in glass
EP1158256A3 (en) * 2000-05-25 2002-01-02 Cryomech, Inc. Pulse-tube cryorefrigeration apparatus using an integrated buffer volume
WO2002004875A1 (en) * 2000-07-05 2002-01-17 Raytheon Company Apparatus and method for achieving temperature stability in a two-stage cryocooler
FR2821150A1 (en) * 2001-02-17 2002-08-23 Lg Electronics Inc Pulse tube refrigerator has cover partially inserted into hollow cylinder with central cylinder combined with pulse tube and regenerator
US6725670B2 (en) 2002-04-10 2004-04-27 The Penn State Research Foundation Thermoacoustic device
US6755027B2 (en) 2002-04-10 2004-06-29 The Penn State Research Foundation Cylindrical spring with integral dynamic gas seal
US6792764B2 (en) 2002-04-10 2004-09-21 The Penn State Research Foundation Compliant enclosure for thermoacoustic device
WO2006078437A1 (en) * 2005-01-19 2006-07-27 Raytheon Company Multi-stage cryocooler with concentric second stage
EP1952076A2 (en) * 2005-10-31 2008-08-06 Clever Fellows Innovation Consortium, Inc. Acoustic cooling device with coldhead and resonant driver separated
CN100424443C (en) * 2007-06-04 2008-10-08 中国科学院上海技术物理研究所 Integrated cold head used for co-axial pulse tube refrigerator
WO2009075911A1 (en) * 2007-12-12 2009-06-18 Carleton Life Support Systems Inc. Field integrated pulse tube cryocooler with sada ii compatibility
CN101298947B (en) * 2008-06-26 2010-06-09 上海交通大学 Screw thread welding integral narrow slit type coaxial pulse-tube refrigerator
CN103884126A (en) * 2012-12-19 2014-06-25 中国科学院理化技术研究所 Coaxial type pulse tube refrigerator
CN109140813A (en) * 2016-11-16 2019-01-04 浙江大学 Compressor is coupled with cryocooler cold head with L-type acoustical match component and refrigeration machine

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU170671U1 (en) * 2016-12-02 2017-05-03 Акционерное общество "Конструкторское бюро точного машиностроения имени А.Э. Нудельмана" Combined deep-cooling system for photodetectors

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2824430A (en) * 1954-02-18 1958-02-25 Philips Corp Cold-gas refrigerator control system
US3188818A (en) * 1963-11-12 1965-06-15 Little Inc A Refrigeration method and apparatus embodying fluid expansion
GB1202203A (en) * 1966-08-02 1970-08-12 Hymatic Eng Co Ltd Improvements relating to refrigerating apparatus
US3877239A (en) * 1974-03-18 1975-04-15 Hughes Aircraft Co Free piston cryogenic refrigerator with phase angle control
US3906739A (en) * 1974-08-26 1975-09-23 Us Army Variable pneumatic volume for cryogenic coolers
US4412423A (en) * 1982-06-16 1983-11-01 The United States Of America As Represented By The Secretary Of The Army Split-cycle cooler with improved pneumatically-driven cooling head
US4713939A (en) * 1986-05-23 1987-12-22 Texas Instruments Incorporated Linear drive motor with symmetric magnetic fields for a cooling system
US5113662A (en) * 1991-02-28 1992-05-19 Mitsubishi Denki Kabushiki Kaisha Cryogenic refrigerator
DE4234678A1 (en) * 1991-10-15 1993-04-22 Aisin Seiki Oscillation pipe refrigeration machine - has radiator, regenerator, heat absorber and oscillation pipe between compression and expansion spaces

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2824430A (en) * 1954-02-18 1958-02-25 Philips Corp Cold-gas refrigerator control system
US3188818A (en) * 1963-11-12 1965-06-15 Little Inc A Refrigeration method and apparatus embodying fluid expansion
GB1202203A (en) * 1966-08-02 1970-08-12 Hymatic Eng Co Ltd Improvements relating to refrigerating apparatus
US3877239A (en) * 1974-03-18 1975-04-15 Hughes Aircraft Co Free piston cryogenic refrigerator with phase angle control
US3906739A (en) * 1974-08-26 1975-09-23 Us Army Variable pneumatic volume for cryogenic coolers
US4412423A (en) * 1982-06-16 1983-11-01 The United States Of America As Represented By The Secretary Of The Army Split-cycle cooler with improved pneumatically-driven cooling head
US4713939A (en) * 1986-05-23 1987-12-22 Texas Instruments Incorporated Linear drive motor with symmetric magnetic fields for a cooling system
US5113662A (en) * 1991-02-28 1992-05-19 Mitsubishi Denki Kabushiki Kaisha Cryogenic refrigerator
DE4234678A1 (en) * 1991-10-15 1993-04-22 Aisin Seiki Oscillation pipe refrigeration machine - has radiator, regenerator, heat absorber and oscillation pipe between compression and expansion spaces

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
R. N. RICHARDSON: "DEVELOPMENT OF A PRACTICAL PULSE TUBE REFRIGERATOR: CO-AXIAL DESIGNS AND THE INFLUENCE OF VISCOSITY", CRYOGENICS, vol. 28, no. 8, August 1988 (1988-08-01), pages 516 - 520, XP022790354, DOI: doi:10.1016/0011-2275(88)90163-4 *

Cited By (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0717245A2 (en) * 1994-12-12 1996-06-19 Hughes Aircraft Company Concentric pulse tube expander
EP0717245A3 (en) * 1994-12-12 1996-07-10 Hughes Aircraft Co
US5613365A (en) * 1994-12-12 1997-03-25 Hughes Electronics Concentric pulse tube expander
FR2736710A1 (en) * 1995-07-12 1997-01-17 Commissariat Energie Atomique REFRIGERATOR OR HEAT PUMP WITH PULSATION TUBE SUPPLIED BY A PRESSURE GENERATOR
WO1997003327A1 (en) * 1995-07-12 1997-01-30 Commissariat A L'energie Atomique Refrigerator or heat pump with a pulse tube operated by a pressure generator
FR2743871A1 (en) * 1996-01-24 1997-07-25 Hughes Aircraft Co DETERGENT FOR A PULSED TUBE CONCENTRIC COOLER, THIS COOLER AND COOLING SYSTEM USING THE SAME
EP0803687A1 (en) * 1996-04-23 1997-10-29 Cryotechnologies Cryostat for cryogenic refrigerator and refrigerators comprising such a cryostat
US5968637A (en) * 1996-05-07 1999-10-19 Thomson-Csf Use of nitride barrier to prevent the diffusion of silver in glass
FR2760076A1 (en) * 1997-02-21 1998-08-28 Cryotechnologies Double effect pressure oscillator for electronic component cooling
WO1999020957A1 (en) * 1997-10-20 1999-04-29 Cornelis Maria De Blok Thermo-acoustic system
US6314740B1 (en) 1997-10-20 2001-11-13 Cornelis Maria De Blok Thermo-acoustic system
EP1158256A3 (en) * 2000-05-25 2002-01-02 Cryomech, Inc. Pulse-tube cryorefrigeration apparatus using an integrated buffer volume
US6378312B1 (en) 2000-05-25 2002-04-30 Cryomech Inc. Pulse-tube cryorefrigeration apparatus using an integrated buffer volume
WO2002004875A1 (en) * 2000-07-05 2002-01-17 Raytheon Company Apparatus and method for achieving temperature stability in a two-stage cryocooler
FR2821150A1 (en) * 2001-02-17 2002-08-23 Lg Electronics Inc Pulse tube refrigerator has cover partially inserted into hollow cylinder with central cylinder combined with pulse tube and regenerator
US6755027B2 (en) 2002-04-10 2004-06-29 The Penn State Research Foundation Cylindrical spring with integral dynamic gas seal
US6792764B2 (en) 2002-04-10 2004-09-21 The Penn State Research Foundation Compliant enclosure for thermoacoustic device
US7055332B2 (en) 2002-04-10 2006-06-06 The Penn State Research Foundation Compliant enclosure for thermoacoustic device
US7143586B2 (en) 2002-04-10 2006-12-05 The Penn State Research Foundation Thermoacoustic device
US6725670B2 (en) 2002-04-10 2004-04-27 The Penn State Research Foundation Thermoacoustic device
WO2006078437A1 (en) * 2005-01-19 2006-07-27 Raytheon Company Multi-stage cryocooler with concentric second stage
US7296418B2 (en) 2005-01-19 2007-11-20 Raytheon Company Multi-stage cryocooler with concentric second stage
EP1952076A4 (en) * 2005-10-31 2010-10-13 Clever Fellows Innovation Cons Acoustic cooling device with coldhead and resonant driver separated
EP1952076A2 (en) * 2005-10-31 2008-08-06 Clever Fellows Innovation Consortium, Inc. Acoustic cooling device with coldhead and resonant driver separated
CN100424443C (en) * 2007-06-04 2008-10-08 中国科学院上海技术物理研究所 Integrated cold head used for co-axial pulse tube refrigerator
WO2009075911A1 (en) * 2007-12-12 2009-06-18 Carleton Life Support Systems Inc. Field integrated pulse tube cryocooler with sada ii compatibility
US8079224B2 (en) 2007-12-12 2011-12-20 Carleton Life Support Systems, Inc. Field integrated pulse tube cryocooler with SADA II compatibility
CN101298947B (en) * 2008-06-26 2010-06-09 上海交通大学 Screw thread welding integral narrow slit type coaxial pulse-tube refrigerator
CN103884126A (en) * 2012-12-19 2014-06-25 中国科学院理化技术研究所 Coaxial type pulse tube refrigerator
CN103884126B (en) * 2012-12-19 2016-02-10 中国科学院理化技术研究所 Coaxial type pulse pipe refrigerator
CN109140813A (en) * 2016-11-16 2019-01-04 浙江大学 Compressor is coupled with cryocooler cold head with L-type acoustical match component and refrigeration machine
CN109140813B (en) * 2016-11-16 2019-10-25 浙江大学 Compressor is coupled with cryocooler cold head with L-type acoustical match component and refrigeration machine

Also Published As

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FR2702269A1 (en) 1994-09-09
EP0614059B1 (en) 1998-12-16
DE69415187T2 (en) 1999-05-20
DE69415187D1 (en) 1999-01-28
FR2702269B1 (en) 1995-04-07

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