CN114739031B - Dilution refrigeration system - Google Patents
Dilution refrigeration system Download PDFInfo
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- CN114739031B CN114739031B CN202210484998.1A CN202210484998A CN114739031B CN 114739031 B CN114739031 B CN 114739031B CN 202210484998 A CN202210484998 A CN 202210484998A CN 114739031 B CN114739031 B CN 114739031B
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- cavity
- heat exchange
- heat exchanger
- cold
- damping
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- 238000010790 dilution Methods 0.000 title claims abstract description 42
- 239000012895 dilution Substances 0.000 title claims abstract description 42
- 238000005057 refrigeration Methods 0.000 title claims abstract description 30
- 238000013016 damping Methods 0.000 claims abstract description 45
- 239000003507 refrigerant Substances 0.000 claims abstract description 17
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 26
- SWQJXJOGLNCZEY-BJUDXGSMSA-N helium-3 atom Chemical group [3He] SWQJXJOGLNCZEY-BJUDXGSMSA-N 0.000 claims description 13
- 238000007789 sealing Methods 0.000 claims description 7
- SWQJXJOGLNCZEY-IGMARMGPSA-N helium-4 atom Chemical group [4He] SWQJXJOGLNCZEY-IGMARMGPSA-N 0.000 claims description 2
- 238000001816 cooling Methods 0.000 abstract description 10
- 230000000694 effects Effects 0.000 abstract description 5
- 239000007789 gas Substances 0.000 description 14
- 239000007788 liquid Substances 0.000 description 12
- 239000001307 helium Substances 0.000 description 7
- 229910052734 helium Inorganic materials 0.000 description 7
- 238000002156 mixing Methods 0.000 description 7
- 238000000605 extraction Methods 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- 238000002955 isolation Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 229910001069 Ti alloy Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000003113 dilution method Methods 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 230000005283 ground state Effects 0.000 description 1
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
Classifications
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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
- F25B9/002—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant
- F25B9/006—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant the refrigerant containing more than one component
-
- 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
- F25B41/00—Fluid-circulation arrangements
- F25B41/30—Expansion means; Dispositions thereof
-
- 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
- F25B41/00—Fluid-circulation arrangements
- F25B41/40—Fluid line 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
- F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
- F25D19/00—Arrangement or mounting of refrigeration units with respect to devices or objects to be refrigerated, e.g. infrared detectors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2500/00—Problems to be solved
- F25B2500/13—Vibrations
Abstract
The invention discloses a dilution refrigeration system, wherein a small-sized low-temperature refrigerator is arranged in a damping heat exchange cavity at the top of a cold box through a corrugated pipe; the top of the small-sized low-temperature refrigerator is suspended and fixed and is not contacted with the inner wall of the damping heat exchange cavity; in the small-sized low-temperature refrigerator, a first-stage cold end is connected with a first-stage cold end heat exchanger, and a second-stage cold end is connected with a second-stage cold end heat exchanger; the outer wall of the cold end heat exchanger is provided with a heat exchange tube, and two ends of the heat exchange tube are respectively provided with a first inlet and a first outlet; the first inlet, the first outlet, the first heat exchange coil, the first flow resistance, the dilution unit and the first exhaust pipe form a first loop; the second inlet, the second outlet, the second heat exchange coil, the second flow resistance, the 1K cavity and the second exhaust pipe form a second loop; the first loop and the second loop exchange heat in the 1K cavity. The invention can reduce the system vibration to below 1 micron, and can form a dry-wet mixed refrigeration cold source in the damping heat exchange cavity, thereby providing pre-cooling and liquefying for multi-loop refrigerant gas and ensuring refrigeration effect.
Description
Technical Field
The invention belongs to the technical field of low-temperature refrigeration, and particularly relates to a dilution refrigeration system.
Background
Dilution refrigeration is the only method at this stage that can continue to provide a temperature-limited environment (< 20 mK) by diluting helium-3 into helium-4 in a mixing chamber to form dilute phase mixed liquid helium, producing a dilution refrigeration effect that absorbs heat from the environment. If helium-3/helium-4 is mixed in a ratio of 6.6%, the dilution refrigeration system can achieve temperatures infinitely close to absolute zero (-273.15 ℃) with sufficiently low ambient temperatures. When the temperature of dilute phase mixed liquid helium is raised to 0.6K (-272.55 ℃), helium-4 in the dilute phase mixed liquid helium is still in a ground state, the saturated vapor pressure of the dilute phase mixed liquid helium is basically zero (similar to vacuum), and the saturated vapor pressure of liquid helium-3 at the temperature is thousands times higher than that of liquid helium-4, so that helium-3 can circulate to a system inlet through a pump group outside the system, and enters a mixing chamber through precooling and heat exchange again to form a continuous operation dilution refrigeration process.
The mixing chamber is used as the lowest temperature part of the dilution refrigeration system, and the main factors influencing the temperature of the mixing chamber are various heat which is continuously input into the system, including heat generated by vibration. In order to achieve extremely low temperature experimental conditions, the heat input to the helium-3/helium-4 dilution process by the external environment needs to be limited, so that on one hand, the liquid helium-3 input into the mixing chamber needs to be fully pre-cooled to a sufficiently low temperature, and on the other hand, the vibration of the system needs to be reduced to the greatest extent.
The dilution refrigerator which is used as a cold source of a dilution refrigeration system in the market is divided into a wet type dilution refrigerator and a dry type dilution refrigerator, wherein the wet type dilution refrigerator adopts liquid helium-4 stored in a low-temperature Dewar as the cold source, and limited cold energy is provided for the dilution refrigeration cycle through vaporizing the liquid helium-4; in addition, the system size is limited by the Du Wachang port size, and the requirement of complex experiments cannot be met.
In recent decades, with the rapid development of small cryocoolers, dilution refrigeration systems employing dry dilution refrigerators have become increasingly popular. Gift-Maxwell (GM) and Pulse-tube (Pulse-tube) refrigerators are two types of small cryocoolers that can achieve 4K temperatures while providing watt-level refrigeration. GM refrigerators generate vibration levels of tens of microns due to the reciprocating motion of the internal piston, while pulse tubes, although without moving parts, have distributing valves and the resulting moving air streams that generate micron-scale vibrations. Therefore, the dry dilution refrigerator widely applied at the present stage mainly uses a pulse tube refrigerator, and meanwhile, the vibration level of submicron level is realized through an isolation distributing valve.
Disclosure of Invention
The invention aims to: the invention aims to provide a dilution refrigeration system with smaller vibration.
The technical scheme is as follows: the dilution refrigeration system comprises a cold box, wherein a damping heat exchange cavity is arranged at the top of the cold box; a small-sized low-temperature refrigerator is arranged in the damping heat exchange cavity in a vacuum sealing way through a corrugated pipe and is used as a system cold source; the top of the small-sized low-temperature refrigerator is suspended and fixed, and the small-sized low-temperature refrigerator is in non-contact with the inner wall of the damping heat exchange cavity.
In the invention, the small-sized low-temperature refrigerator is suspended, the small-sized low-temperature refrigerator is not contacted with the inner wall of the damping heat exchange cavity, and the corrugated pipe also has the function of isolating vibration, so that the vibration transmitted to the cold box by the small-sized low-temperature refrigerator can be reduced to the maximum extent, and the rise of the lowest temperature of the system caused by heat input caused by vibration is avoided. The invention can lead the system to achieve the excellent performance of vibration far lower than 1 micrometer.
Further, the small-sized low-temperature refrigerator is provided with at least two stages of cold ends, and comprises a primary cold end and a secondary cold end, wherein the primary cold end is connected with a primary cold end heat exchanger, and the secondary cold end is connected with a secondary cold end heat exchanger; a cavity primary heat exchanger and a cavity secondary heat exchanger are arranged on a cavity wall plate of the damping heat exchange cavity, the cavity primary heat exchanger is not contacted with the cold end primary heat exchanger, and the cavity secondary heat exchanger is not contacted with the cold end secondary heat exchanger;
the cold box is also provided with a second flow resistance, a 1K cavity and a first flow resistance, the outer walls of the cavity primary heat exchanger and the cavity secondary heat exchanger are provided with heat exchange tubes, one end of each heat exchange tube extending out of the cold box is a first inlet, and the other end of each heat exchange tube is a first outlet; the upper part of the damping heat exchange cavity is provided with a second inlet communicated with the inner cavity of the damping heat exchange cavity, and the bottom of the damping heat exchange cavity is provided with a second outlet; the 1K cavity is connected with a second exhaust pipe, and a dilution unit in the cold box is connected with a first exhaust pipe; the second extraction pipe is internally provided with a second heat exchange coil, and the first extraction pipe is internally provided with a first heat exchange coil;
the first inlet, the first outlet, the first heat exchange coil, the first flow resistance, the dilution unit and the first exhaust pipe form a first loop; the second inlet, the second outlet, the second heat exchange coil, the second flow resistance, the 1K cavity and the second exhaust pipe form a second loop; the first loop and the second loop exchange heat in a 1K cavity; the first loop refrigerant is helium-3 and helium-4 mixed gas; the second loop refrigerant is helium-4 gas.
In the technical scheme, the multichannel coil pipes are arranged outside the damping heat exchange cavity, the precooling and liquefying of multichannel refrigerant gas can be realized, the refrigerant gas exchanges heat on the primary heat exchanger and the secondary heat exchanger of the outer cavity of the damping heat exchange cavity through the first loop, the heat exchange is performed inside the damping heat exchange cavity through the second loop, the precooling can be provided for the system both outside and inside the damping heat exchange cavity, and the heat exchange structure is compact. In the cavity, the temperature of helium-4 at the second outlet can be reduced to below 5K, and a small amount of liquid ammonia is formed in the damping heat exchange cavity, so that a dry-wet concurrent mixed refrigeration cold source is formed, stable circulation of the system in a certain time can be ensured under the condition of power failure, and external liquid helium is not required to be added. The temperature of helium-4 is lower than 2K after the second flow resistance throttling, and the pre-cooling can be continuously provided for the mixed gas of helium-3 and helium-4 in the 1K cavity, so that the refrigerating effect is good. The loop is formed by air suction, and the refrigerant is not easy to leak under the negative pressure operation. In addition, the damping heat exchange cavity is completely isolated from the vacuum environment in the cold box, so that refrigerant gas in the damping heat exchange cavity can be prevented from leaking and entering the vacuum environment of the cold box, and the effect of non-destructive closed circulation of the refrigerant gas is achieved.
Optionally, the small cryorefrigerator at least has two stages of cold ends, including a first stage cold end and a second stage cold end, the first stage cold end is connected with a first stage cold end heat exchanger, and the second stage cold end is connected with a second stage cold end heat exchanger; a cavity primary heat exchanger and a cavity secondary heat exchanger are arranged on a cavity wall plate of the damping heat exchange cavity, the cavity primary heat exchanger is not contacted with the cold end primary heat exchanger, and the cavity secondary heat exchanger is not contacted with the cold end secondary heat exchanger; the cooling box is also provided with a first flow resistance, the upper part of the damping heat exchange cavity is provided with a second inlet communicated with the inner cavity of the damping heat exchange cavity, and the bottom of the damping heat exchange cavity is provided with a second outlet; the dilution unit in the cold box is connected with a first exhaust pipe, and a first heat exchange coil is arranged in the first exhaust pipe; the second inlet, the second outlet, the first heat exchange coil, the first flow resistance, the dilution unit and the first exhaust pipe form a loop; the loop refrigerant is helium-3 and helium-4 mixed gas.
In the technical scheme, no separate helium-4 loop is arranged, the refrigerating capacity of the small-sized low-temperature refrigerator can be efficiently utilized, the flow of the system is greatly increased, and the dilution refrigerating capacity is improved.
In the technical scheme, the corrugated pipe adopts a metal corrugated pipe or a rubber corrugated pipe. The cavity wall plate adopts low heat conductivity materials such as stainless steel, titanium alloy and the like, and the structural form is a straight pipe or a corrugated pipe. The cavity wall plate is connected with the cavity primary heat exchanger and the cavity secondary heat exchanger by adopting welding, soldering or indium wire sealing and other modes to form a vacuum sealing cavity.
Further, the damping heat exchange cavity is connected with a cold box room temperature flange at the top of the cold box through a cavity room temperature flange at the top of the damping heat exchange cavity; the cold box is internally provided with a multi-stage cold disc and a multi-stage cold screen to form a multi-layer low-temperature cavity; the cavity primary heat exchanger is connected with the primary cold plate at the uppermost layer, the cavity secondary heat exchanger is connected with the secondary cold plate at the next upper layer, and a high vacuum sealing environment is formed in the cold box. The cavity primary heat exchanger provides cooling for the primary cold plate, and the cavity secondary heat exchanger provides cooling for the secondary cold plate. The damping heat exchange cavity is connected with the cold box flange, so that the damping heat exchange cavity can be easily taken out when the small-sized cryocooler needs maintenance or replacement.
Preferably, the cavity heat exchanger is fixedly connected with the corresponding cold disc by hard connection or connected by a heat conduction soft chain.
Furthermore, a staggered fin, interdigital or lantern ring heat exchange structure is adopted between the cavity primary heat exchanger and the cold end primary heat exchanger and between the cavity secondary heat exchanger and the cold end secondary heat exchanger. The cold end primary heat exchanger, the cold end secondary heat exchanger, the cavity primary heat exchanger and the cavity secondary heat exchanger are made of high-purity high-heat-conductivity materials such as copper, aluminum, silver, gold and the like.
Further, the distance between the cavity heat exchanger and the cold end heat exchanger is 0.01-5 mm.
Further, the flow resistance adopts a capillary tube or a low-temperature valve, the capillary tube is a fixed flow resistance, and the flow resistance of the low-temperature valve is adjustable. The temperature of the liquid helium entering the dilution unit (evaporation chamber) can be controlled by the first flow resistance. The 1K cavity operating temperature can be controlled by the second flow resistance.
Further, a support rod is fixed at the top of the small cryocooler and is fixed on a support fixed on a reinforced ground or a low-vibration platform. The support rod and the bracket are made of aluminum alloy or stainless steel.
Further, a small cryocooler is used as a gifford-mcmahon (GM) refrigerator or a Pulse-tube (Pulse-tube) refrigerator.
The beneficial effects are that: compared with the prior art, the invention has the following remarkable advantages: the invention separates the small-sized low-temperature refrigerator from the cold box based on the damping heat exchange cavity structure, and can reduce the system vibration to be far lower than 1 micron.
Drawings
FIG. 1 is a schematic view of a shock absorbing heat exchange cavity;
fig. 2 is a schematic view of the structure of the dilution refrigeration system in the first embodiment;
fig. 3 is a schematic diagram of a dilution refrigeration system according to the second embodiment.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings.
Example 1
As shown in fig. 1 and 2, a dilution refrigeration system includes a cold box 14, wherein a primary cold plate 15, a secondary cold plate 17, a tertiary cold plate 19, a quaternary cold plate 21, a quintupled cold plate 22 and a hexahydric cold plate 23, and a primary cold plate 16, a secondary cold plate 18, a tertiary cold plate 20 and a quaternary cold plate 24 are arranged inside the cold box 14. The top of the cold box 14 is provided with a cold box room temperature flange 13. The top of the cold box 14 is provided with a damping heat exchange cavity 31, the damping heat exchange cavity 31 is formed by assembling and welding a cavity primary heat exchanger 4, a cavity secondary heat exchanger 5 and a cavity wall plate 35, and the top of the damping heat exchange cavity 31 is provided with a cavity room temperature flange 36. The damping heat exchange cavity 31 is inserted from top to bottom from the top of the cold box 14, is connected with the cold box room temperature flange 13 through a cavity room temperature flange 36, is connected with the first-stage cold plate 15 by the cavity first-stage heat exchanger 4, is connected with the second-stage cold plate 17 by the cavity second-stage heat exchanger 5, and forms a vacuum sealing cavity in the cold box 14.
The small-sized cryocooler 1 is inserted into the shock-absorbing heat-exchanging cavity 31 and is connected with the shock-absorbing heat-exchanging cavity 31 in the circumferential direction through the corrugated pipe 2, and a vacuum sealing environment is formed in the shock-absorbing heat-exchanging cavity 31 in the same way. The small cryorefrigerator 1 is provided with two stages of cold ends, comprising a primary cold end 33 and a secondary cold end 34, wherein the primary cold end 33 is connected with a primary cold end heat exchanger 37, and the secondary cold end 34 is connected with a secondary cold end heat exchanger 38; the top of the small-sized low-temperature refrigerator 1 is fixed through a bracket system formed by a supporting rod 28 and a bracket 29, so that the cavity primary heat exchanger 4 is not contacted with the cold end primary heat exchanger 37, the cavity secondary heat exchanger 5 is not contacted with the cold end secondary heat exchanger 38, and vibration isolation between the small-sized low-temperature refrigerator 1 and the cold box 14 is realized; the cold box 14 is also provided with a second flow resistance 6, a 1K cavity 7 and a first flow resistance 8, the outer walls of the cavity primary heat exchanger 4 and the cavity secondary heat exchanger 5 are provided with heat exchange pipes, one end of each heat exchange pipe extending out of the cold box 14 is provided with a first inlet 3, and the other end of each heat exchange pipe is provided with a first outlet 41; the upper part of the damping heat exchange cavity 31 is provided with a second inlet 25 communicated with the inner cavity of the damping heat exchange cavity, and the bottom of the damping heat exchange cavity 31 is provided with a second outlet 40; the 1K cavity 7 is connected with a second exhaust pipe 26, and a dilution unit in the cold box 14 is connected with a first exhaust pipe 27; the second extraction pipe 26 is provided with a second heat exchange coil 39, and the first extraction pipe 27 is provided with a first heat exchange coil 32.
In the first loop, the refrigerant adopts helium-3 and helium-4 mixed gas, enters the cold box 14 from the first inlet 3, exchanges heat through the outer walls of the cavity primary heat exchanger 4 and the cavity secondary heat exchanger 5 by the heat exchange tubes, exchanges heat in the 1K cavity 7 by the first heat exchange coil 32 in the first exhaust tube 27 after being partially liquefied, then flows into the dilution unit (comprising the evaporation chamber 9, the double-pipe heat exchanger 10, the stepped heat exchanger 11 and the mixing chamber 12) through the first flow resistor 8, and is pumped back to the first inlet 3 by the first exhaust tube 27 through the circulating pump. And the second loop adopts refrigerant gas helium-4, enters the cold box 14 from the second inlet 25, passes through the primary cold end 33, the secondary cold end 34, the cavity primary heat exchanger 4 and the cavity secondary heat exchanger 5 for precooling, reduces the temperature of the refrigerant gas to below 5K, and forms a small amount of liquid helium in the cavity. Then, the mixture flows into a 1K cavity 7 through the throttling of a second flow resistor 6 to form a low-temperature cold source lower than 2K, and precooling is continuously provided for helium-3 and helium-4 mixed gas. The refrigerant gas evaporated in the 1K cavity 7 is pumped out by the second pumping pipe 26 through the circulating pump and returns to the second inlet 25. In this embodiment, the temperature of the primary cooling plate 15 is between 30 and 70K, and the temperature of the secondary cooling plate 17 is between 2 and 5K.
Example two
Unlike the first embodiment, the tertiary cooling pan 19, the tertiary cooling screen 20 and the heat exchange tubes arranged on the outer walls of the cavity heat exchangers 4, 5 are eliminated, and a separate helium-4 circuit is not provided. The refrigerant helium-3 and helium-4 mixture directly enters the damping heat exchange cavity 31 from the second inlet 25, enters the first heat exchange coil 32 in the first exhaust tube 27 after passing through the first-stage cold end 33, the second-stage cold end 34, the cavity first-stage heat exchanger 4 and the cavity second-stage heat exchanger 5 for heat exchange, flows into the dilution unit (comprising the evaporation chamber 9, the double-pipe heat exchanger 10, the stepped heat exchanger 11 and the mixing chamber 12) after being throttled by the first flow resistance 8, and finally is pumped back to the first inlet 3 by the first exhaust tube 27 through the circulating pump.
The invention is based on the special damping heat exchange cavity, on one hand, multi-stage efficient heat conduction can be constructed, and the pre-cooling is carried out for refrigerant gas; on the other hand, the small-sized low-temperature refrigerator and the cold box can realize non-contact vibration isolation, and the refrigeration effect is ensured.
Claims (7)
1. A dilution refrigeration system comprising a cold box (14), characterized in that: the top of the cold box (14) is provided with a damping heat exchange cavity (31); a small-sized low-temperature refrigerator (1) is arranged in the damping heat exchange cavity (31) in a vacuum sealing way through a corrugated pipe (2) and is used as a system cold source; the top of the small-sized low-temperature refrigerator (1) is suspended and fixed, and the small-sized low-temperature refrigerator (1) is in non-contact with the inner wall of the damping heat exchange cavity (31);
the small-sized low-temperature refrigerator (1) is provided with at least two stages of cold ends, and comprises a primary cold end (33) and a secondary cold end (34), wherein the primary cold end (33) is connected with a primary cold end heat exchanger (37), and the secondary cold end (34) is connected with a secondary cold end heat exchanger (38); a cavity primary heat exchanger (4) and a cavity secondary heat exchanger (5) are arranged on a cavity wall plate (35) of the damping heat exchange cavity (31), the cavity primary heat exchanger (4) is not contacted with a cold end primary heat exchanger (37), and the cavity secondary heat exchanger (5) is not contacted with a cold end secondary heat exchanger (38);
the cold box (14) is also provided with a second flow resistor (6), a 1K cavity (7) and a first flow resistor (8), the outer walls of the cavity primary heat exchanger (4) and the cavity secondary heat exchanger (5) are provided with heat exchange pipes, one end of each heat exchange pipe extending out of the cold box (14) is provided with a first inlet (3), and the other end of each heat exchange pipe is provided with a first outlet (41); the upper part of the damping heat exchange cavity (31) is provided with a second inlet (25) communicated with the inner cavity of the damping heat exchange cavity, and the bottom of the damping heat exchange cavity (31) is provided with a second outlet (40); the 1K cavity (7) is connected with a second exhaust pipe (26), and a dilution unit in the cold box (14) is connected with a first exhaust pipe (27); a second heat exchange coil (39) is arranged in the second exhaust pipe (26), and a first heat exchange coil (32) is arranged in the first exhaust pipe (27);
the first inlet (3), the first outlet (41), the first heat exchange coil (32), the first flow resistor (8), the dilution unit and the first exhaust pipe (27) form a first loop; the second inlet (25), the second outlet (40), the second heat exchange coil (39), the second flow resistor (6), the 1K cavity (7) and the second exhaust pipe (26) form a second loop; the first loop and the second loop exchange heat in a 1K cavity (7); the first loop refrigerant is helium-3 and helium-4 mixed gas; the second loop refrigerant is helium-4 gas.
2. The dilution refrigeration system of claim 1, wherein: the damping heat exchange cavity (31) is connected with a cold box room temperature flange (13) at the top of the cold box (14) through a cavity room temperature flange (36) at the top of the damping heat exchange cavity; a multi-stage cold tray and a multi-stage cold screen are arranged in the cold box (14) to form a multi-layer low-temperature cavity; the cavity primary heat exchanger (4) is connected with the primary cold plate (15) at the uppermost layer, and the cavity secondary heat exchanger (5) is connected with the secondary cold plate (17) at the next upper layer.
3. The dilution refrigeration system of claim 1, wherein: the cavity primary heat exchanger (4) and the cold end primary heat exchanger (37), and the cavity secondary heat exchanger (5) and the cold end secondary heat exchanger (38) adopt staggered fin, interdigital or lantern ring heat exchange structures.
4. A dilution refrigeration system according to claim 3, wherein: the distance between the cavity heat exchanger and the cold end heat exchanger is 0.01-5 mm.
5. The dilution refrigeration system of claim 1, wherein: the flow resistance is a capillary or a cryogenic valve.
6. The dilution refrigeration system of claim 1, wherein: a supporting rod (28) is fixed at the top of the small-sized cryocooler (1), the supporting rod (28) is fixed on a support (29), and the support (29) is fixed on a reinforced ground or a low-vibration platform.
7. The dilution refrigeration system of claim 1, wherein: the small cryorefrigerator (1) adopts a Gifford-Maxwell refrigerator or a pulse tube refrigerator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210484998.1A CN114739031B (en) | 2022-05-06 | 2022-05-06 | Dilution refrigeration system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210484998.1A CN114739031B (en) | 2022-05-06 | 2022-05-06 | Dilution refrigeration system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114739031A CN114739031A (en) | 2022-07-12 |
| CN114739031B true CN114739031B (en) | 2023-09-15 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210484998.1A Active CN114739031B (en) | 2022-05-06 | 2022-05-06 | Dilution refrigeration system |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117553445B (en) * | 2024-01-09 | 2024-03-22 | 浙江拓感科技有限公司 | Infrared detector quick start integrated refrigerator subassembly |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3195322A (en) * | 1961-09-22 | 1965-07-20 | Atomic Energy Authority Uk | Refrigerator employing helium |
| JP2004293996A (en) * | 2003-03-28 | 2004-10-21 | Taiyo Toyo Sanso Co Ltd | Dillution refrigerator |
| JP2005090928A (en) * | 2003-09-22 | 2005-04-07 | Sumitomo Heavy Ind Ltd | Dilution refrigerating machine |
| JP2017187261A (en) * | 2016-03-31 | 2017-10-12 | 大陽日酸株式会社 | Dilution refrigeration machine |
| CN107655236A (en) * | 2017-09-25 | 2018-02-02 | 清华大学 | Ultralow vibration cryostat |
| CN110440912A (en) * | 2019-08-19 | 2019-11-12 | 中国电子科技集团公司第四十一研究所 | A kind of use for laboratory low temperature radiometer |
| CN111089436A (en) * | 2019-12-24 | 2020-05-01 | 中船重工鹏力（南京）超低温技术有限公司 | Low-vibration low-temperature magnetic field measuring device based on cooling of GM refrigerator |
| CN111854214A (en) * | 2020-08-10 | 2020-10-30 | 中船重工鹏力（南京）超低温技术有限公司 | Low temperature system for realizing ultralow vibration under 2K based on GM refrigerator |
-
2022
- 2022-05-06 CN CN202210484998.1A patent/CN114739031B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3195322A (en) * | 1961-09-22 | 1965-07-20 | Atomic Energy Authority Uk | Refrigerator employing helium |
| JP2004293996A (en) * | 2003-03-28 | 2004-10-21 | Taiyo Toyo Sanso Co Ltd | Dillution refrigerator |
| JP2005090928A (en) * | 2003-09-22 | 2005-04-07 | Sumitomo Heavy Ind Ltd | Dilution refrigerating machine |
| JP2017187261A (en) * | 2016-03-31 | 2017-10-12 | 大陽日酸株式会社 | Dilution refrigeration machine |
| CN107655236A (en) * | 2017-09-25 | 2018-02-02 | 清华大学 | Ultralow vibration cryostat |
| CN110440912A (en) * | 2019-08-19 | 2019-11-12 | 中国电子科技集团公司第四十一研究所 | A kind of use for laboratory low temperature radiometer |
| CN111089436A (en) * | 2019-12-24 | 2020-05-01 | 中船重工鹏力（南京）超低温技术有限公司 | Low-vibration low-temperature magnetic field measuring device based on cooling of GM refrigerator |
| CN111854214A (en) * | 2020-08-10 | 2020-10-30 | 中船重工鹏力（南京）超低温技术有限公司 | Low temperature system for realizing ultralow vibration under 2K based on GM refrigerator |
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| CN114739031A (en) | 2022-07-12 |
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