436 results about "Pulse tube refrigerator" patented technology

A pulse tube refrigerator includes a regenerator including a cold end and a hot end, a cold head connected to the cold end of the regenerator, a pulse tube having a cold end and a hot end and connected at its cold end to the cold head, a pressure fluctuation source connected to the hot end of the regenerator, a buffer connected to the hot end of the pulse tube through an orifice, and an auxiliary buffer connected to the hot end of the pulse tube through a buffer side control valve. The buffer and the auxiliary buffer may be replaced by a single buffer connected to the hot end of the pulse tube through an orifice and a buffer side control valve which are arranged in parallel.

An inertance tube and a surge volume for a pulse tube refrigerator system may be integrally coupled together, such as by the inertance tube being at least in part a channel in a wall of the surge volume. The surge volume may have a helical channel in an outer wall that forms part of the inertance tube. The surge volume tank may be surrounded by a cover that closes off the channel to form the inertance tube as an integral part of the surge volume. The inertance tube may have a non-circular cross section shape, such as a square shape or non-square rectangular shape. The channel may be tapered, perhaps changing aspect ratio. Alternatively, the inertance tube may be a separate tube having a non-circular shape, which may be wrapped around at least part of the surge volume.

A double inlet passage 70 connects a compressor 40 to remote end 53 of a vortex tube 51 that serves as the heat-rejecting heat exchanger of an orifice pulse tube refrigerator. Double inlet passage 70 includes means 3 for controlling DC flow in that passage. Fluid flows between compressor and reservoir enhance heat-rejecting effectiveness of vortex tube 51.

The invention relates to a linear type double-acting refrigeration system. The linear type double-acting refrigeration system consists of N pulse tube refrigerators and N-1 linear type double-acting compressors, which are serially connected between a linear type compressor and a linear type electric generator in sequence and arranged at intervals, wherein the linear type compressor is positioned at the beginning end of the system, and the linear type electric generator is positioned at the tail end of the system; each of the linear type compressor and the linear type electric generator works in a single-piston manner; two pistons of each linear type double-acting compressor work at the same time; N is a positive integer of 2-20. According to the system, inertial tubes and air reservoirs or two-way air inlet equal phase-modulation structures in a traditional pulse tube refrigerator are omitted, so that the structure is compact; required phase can be realized by adjusting the frequency characteristics of linear motors at both ends of each pulse tube refrigerator and motion phases of compression pistons and expansion pistons; the flow-out sound power of the refrigerators is free of dissipation, and is absorbed by the expansion pistons of the linear motors, so that high efficiency and large refrigerating capacity can be obtained; the linear type double-acting refrigeration system has good application prospect in occasions requiring the refrigerators to obtain large refrigerating capacity, high efficiency and long service life.

The pulse tube 59 of a pulse tube refrigerator is equipped with a thin liner 80 of low thermal mass and in poor thermal contact with pulse tube 59. One surface of liner 80 may be furnished with indented recesses 86, making the recessed portions of the liner thinner than the remainder of the material of liner.

A cryogenic refrigerator includes a regenerative heat exchanger material in thermal contact with a working gas including a tin-antimony (Sn—Sb) alloy or a tin-gallium (Sn—Ga) alloy in at least one cooling stage. The re-generative heat exchanger material can include an Sn—Sb-M alloy, with M including at least one element selected from the group consisting of Bi, Ag, Ge, Cu, La, Mg, Mn, Nd, Ni, Pd, Pt, K, Rh, Sm, Se, S, Y, Fe, In, Al, Ce, Dy, Cd, Ti, Au, P, Pr, Yb and Zn. The cryogenic refrigerator can include a Gifford-McMahon refrigerator, a pulse tube refrigerator, or a Stirling refrigerator. A cryopump includes cryopanels adapted to condense or adsorb gases and a cryogenic refrigerator.

A densifier is provided which in one embodiment can simultaneously densify two cryogenic liquids at different temperatures. The densifier has an oscillatory power source for generating oscillatory power and a two stage pulse tube refrigerator. The oscillatory power source can be a thermoacoustic heat engine or a mechanical oscillatory power source such as a linear flexure bearing compressor. The first stage densifies a first cryogenic liquid to a first cryogenic temperature, and the second stage densifies a second cryogenic liquid to a second, lower cryogenic temperature. A densified propellant management system also is provided which has a densifier for simultaneously densifying two cryogenic liquids at different temperatures, and a cryogenic temperature probe for measuring the temperature gradient in a cryogenic liquid.

A two-stage pulse tube refrigerator having a compact design, low vibration and low heat loss is provided where at least the 2^nd stage is co-axial but preferably, both stages are co-axial with the second stage pulse tube being central and the first stage pulse tube occupying the annular space between the second stage pulse tube and the first stage regenerator. Convection losses associated with different temperature profiles in the pulse tubes and regenerators are minimized by shifting the thermal patterns in the pulse tubes relative to the regenerators by one or more of spacers in the regenerators, physical differences in length with gas channel connections, adjustment of dc flow, and thermal bridges.

The invention relates to a multistage Stirling type pulse tube refrigerator. The multistage Stirling type pulse tube refrigerator comprises a compressor, n stages of cooling heads and n stages of ladder push piston systems, wherein n is an integer larger than 1, each cooling head comprises a cooler, a heat regenerator, a cooling heat exchanger and pulse tubes, the cooling heat exchanger of the n stage of cooling head serves as the n stage of cooling capacity output end, a compression cavity of the compressor is connected with coolers in the cooling heads, push piston working cavities of the n stages of ladder push piston systems are respectively connected with the pulse tubes, push piston back working cavities of the n stages of ladder push piston systems are communicated with the compression cavity of the compressor, wherein a regulating cavity is connected between the pulse tube of at least one stage of cooling head and the connected ladder push piston working cavity. Compared with the prior art, the multistage Stirling type pulse tube refrigerator enables the gas flow rate and pressure of the cold ends of the pulse tubes to work at the best phase angles through regulating the volume of the cavity, and meanwhile, the multistage Stirling type pulse tube refrigerator gives consideration to the input power distribution of each stage, and moreover, the expansion power can be recycled, and the theoretical efficiency is the same with that of a Carnot engine.

This invention discloses a bi-directional air intake pulse tube refrigerator, which contains compressor, heat exchanger at heat end of heat regenerator, cold heat, pulse tube, pulse tube heat end exchanger, small hole valve, air reservoir, corrugated pipe dc block structure in heat end of pulse tube, and capillary set between air inlet of heat regenerator and heat end of pulse tube. Said invention eliminates the influence of dc to refrigeration temperature and quantity, and operation stability.

Disclosed is a two-stage pulse tube cryopump cooling system in which the pulse tubes and valves are inline, with the hot ends of the pulse tubes at the top and the valve mechanism is at the bottom and the hot ends and buffer volume are cooled by an inline coolant line from the compressor input to the compressor output and attached in heat exchange relationship with the buffer volume.

The invention discloses a thread weld integral slit type cold head of the coxial vessle refrigerator in the refrigeration technology field, including an upper cold head, a lower cold head, a cold end baffle and a copper wire, wherein the upper cold head and the lower cold head are welded again after the threaded connection, the cold baffle is arranged at the middle of the cold head integer, and the cold baffle is filled with the copper wire, wherein the lower cold head is divided into a base seat and a boss having the uniformly distributed slots in the axial symmetry. The depth of the slot is the same with the height of the boss, and the external thread is arranged at the cirumferential of the base seat; a cylinder is arranged on the upper cold head, a round hole at the center and radial slots in the distributed uniformly arranged at the cirumferential of the round hole. The width of the slot is consistent with the slot of the lower cold head; the internal thread structure of the upper cold head is matched with the external thread of the lower cold head, with the other end in the thread match with the cold accumulator, and is left with the margin for welding after being matched. The invention has large heat exchange area, and the welding structure ensures the leak detection safety of the pressure gas the welding reliability.

A kind of integrated cold head is used to the coaxial vas freezer and the cold head is made of the high heat conductivity material and at the bottom along the outside around there is a flanged edge used to weld with the shell of storage cold equipment and in the middle of it opens a round hole and around of the round hole opens radial gap uniformly and the depth of gap is the same with the depth of round hole and there is coaxial opening a ring conduit used to the vas of freezer for inserting. The vas adapts with the inserted ring conduit tightly and the cold head adapts with the shell of storage cold equipment tightly and the flanged edge of cold head welds with the shell of storage cold equipment. So the outside of the ring conduit is the storage cold equipment's cold end gas uniform equipment and the inside of the ring conduit is the vas's cold end gas vane. And the gas in the storage equipment and the vas is conducted by the gap of the bottom of integrated cold head. The maxim merit of it is that: the heat exchange area is large and the affection of guiding flow is well and the points of welding are little and it can deliver the quantity of refrigeration of the vas freezer to the outside face of cold head effectively so it improves performance of the coaxial vas freezer largely.

The invention discloses a vibration reduction type cold head container for a superconducting magnet. The container is characterized by comprising a cold head container upper flange (21), a cold head container lower flange (22), a corrugated pipe (13), a primary stainless steel thin-wall pipe (14), a cold head container primary heat-conducting flange (15), a secondary stainless steel thin-wall pipe (18), a magnetic shielding cylinder (16), a bottom connecting corrugated pipe (20) and the like, wherein the vibration reduction corrugated pipe (13) is arranged between the cold head container upper flange (21) and the cold head container lower flange (22); the upper part of the primary stainless steel thin-wall pipe (14) is connected with the cold head container upper flange (21) in an argon arc welding manner, and the lower part of the primary stainless steel thin-wall pipe (14) is connected with the cold head container primary heat-conducting flange (15) in a vacuum brazing manner; the lower part of the cold head container primary heat-conducting flange (15) is connected with the secondary stainless steel thin-wall pipe (18); the bottom of the secondary stainless steel thin-wall pipe (18) is provided with the corrugated pipe (20); the magnetic shielding cylinder (16) is sleeved outside the secondary stainless steel thin-wall pipe (18); and a GM (Gifford-Mcmahon) refrigerator (6) or a pulse tube refrigerator (7) is arranged in the cold head container (1).

A densifier (10) for simultaneously densifying two cryogenic liquids at different temperatures is provided. The densifier (10) has a thermoacoustic heat engine (20), a resonance tube (18) and a two stage pulse tube refrigerator (40). The thermoacoustic heat engine (20) generates oscillatory acoustical power required to generate net refrigeration power in the two-stage pulse tube refrigerator (40). The first stage (100) densifies a first cryogenic liquid to a first cryogenic temperature, and the second stage (200) densifies a second cryogenic liquid to a second, lower cryogenic temperature. The thermoacoustic heat engine (20) converts thermal energy to the oscillatory acoustical power required to generate net refrigeration in the first (100) and second (200) stages of the pulse tube refrigerator (40). No mechanical energy input is required, and therefore the invented densifier (10) has no moving parts.

The invention relates to a low temperature scanning probe microscope system based on pulse tube refrigeration technology. Aimed at vibration source and characteristics, a multistage active/ passive damping device, including a sylphon bellowss, a piezoelectric ceramic tube and a spring are adopted. The sylphon bellowss is used for connecting a main system cavity and a refrigeration head of the pulse tube to realize vibration isolation of the whole system. As for low frequency vibration unique to a pulse tube refrigerator, an active damping device with a piezoelectric ceramic tube and a digital signal processor as the core is adopted. A beryllium copper spring and a damping magnet form a first stage passive damping device to isolate vibration. The system eliminates the vibration from the pulse tube refrigerator and the refrigeration head to the scanning probe, applies to other vibration sensitive occasions that require low temperature, saves a large amount of liquid helium refrigerant, simplifies equipment operation and maintenance, and significantly prolongs the retention time at low temperature.

The invention discloses a pulse tube refrigerator with a precooling pulse tube. A compressor, a hot end connecting tube, a heat regenerator hot end heat exchanger, a first heat regenerator, a first cold end heat exchanger, a first pulse tube, a first pulse tube hot end heat exchanger and a first phase modulating device are connected in sequence; a second heat regenerator, a second cold end heat exchanger, a cold end connecting tube, a second pulse tube, a pulse tube precooling heat exchanger, a second pulse tube hot end heat exchanger and a second phase modulating device are connected in sequence; and the pulse tube precooling heat exchanger is connected with the first cold end heat exchanger. In the invention, the pulse tube is provided with the precooling heat exchanger, so that the temperature gradient of the near cold end of the pulse tube is reduced, and heat loss of the pulse tube is reduced; and meanwhile, the precooling heat exchanger can assist the pulse tube to carry away the heat of gas in the tube, so that the refrigerating performance of a cold head is enhanced. For a multi-stage pulse tube refrigerator, the precooling amount of a next stage pulse tube is supplied by a previous stage cold head or heat regenerator, so that the performance of the cold head in a low-temperature region can be enhanced greatly only by using a cold quantity precooling pulse tube with a smaller high-temperature region. The pulse tube refrigerator is easy to operate and implement.

The invention discloses a conical slit-type hot end heat exchanger of a coaxial pulse tube refrigerator and a manufacturing method. The heat exchanger structurally consists of a hot end flange, a conical slit and a hot end plug, wherein the conical slit is inserted into the hot end flange in a tight fit way, the radius of a circle of contact on the top of a cone frustum is equal to the radius of a cold accumulator and the radius of the bottom of the cone frustum is equal to the radius of the hot end plug. The hot end plug and the hot end flange not only can be connected through bolts to form a detachable split-type hot end heat exchanger, but also can be hermetically welded to form an integrated hot end radiator. The conical slit-type hot end heat exchanger has the advantages that the structure is simple, compact and high-efficiency, the hot end radiating capacity of the refrigerator can be exerted to the utmost extent and the hot end pressure ratio of the pulse tube refrigerator is increased at the same time. The structure can intensively realize the major functions of a high-efficiency hot end heat exchanger, a hot end gas flow guide device of the pulse tube refrigerator and a hot end gas even distributor of the cold accumulator, and can improve the performance of the entire pulse tube refrigerator to a great extent.

The invention discloses a Stirling pulse tube refrigerator connected with a displacer. A cold end of a first-stage pulse tube refrigerator is connected with one end of the displacer; the other end of the displacer is connected with a room temperature end of a second-stage pulse tube refrigerator; one or more second-stage pulse tube refrigerators are connected in parallel, or one or more second-stage pulse tube refrigerators are connected in series; the displacer comprises a free single-piston type displacer, a single-piston supporting type displacer and a double-piston supporting type displacer; the free single-piston type displacer is provided with a piston only; a piston of the single-piston supporting type displacer is arranged on one side of an elastic part, and a connecting rod is arranged on the piston and is connected with the elastic part; and pistons of the double-piston supporting type displacer are arranged on two sides of the elastic part, and a connecting rod is arranged between the two pistons and is connected with the elastic part. Compared with the conventional multi-stage pulse tube refrigerator, the Stirling pulse tube refrigerator is connected with the displacer, so that the system is more compact, phase modulation is flexible and accurate, the loss of acoustical power transmitted among stages is reduced, more acoustical power is transmitted to the next stage, large cold quantity is obtained, and the whole system operates more efficiently.

The invention relates to a non-magnetic low vibration coaxial pulse tube refrigerating machine wherein the pulse tube and the cold accumulation device are in coaxial arrangement, between which cold accumulation stuffing is filled, an arched flow diverter is arranged on an extending section and the end portion, closely spaced vertical through-holes are arranged on the arched portion, vertical grooves are arranged evenly circular ring external wall, the cover type cold end heat exchanger covers the groove and packs by bonding, the horizontal split cold platform supported by the support rod and fixed on the hot end flange vertically are arranged on the cold end heat exchanger, the cold platform and cold end heat exchanger are connected by flexible heat guide band, the coupling channel under the throttle holes are connected to phase modulation capillary.

The present invention relates to valved cryogenic refrigerators, in particular, Gifford McMahon (GM) refrigerators, and GM type pulse tube refrigerators where gas is cycled between high and low pressures by a valve mechanism that connects to an expander. Input power is reduced by use of a buffer volume which stores gas that flows to and from the warm end of the regenerator through a valve that opens and closes during the periods when the main supply and return valves are closed and is closed when the main supply and return valves are open.

The invention discloses a deep hypothermic heat regenerator adopting helium as a heat regeneration medium. The heat regenerator comprises a tube shell and heat regeneration padding arranged in the tube shell. The heat regeneration padding is of a sealed heat exchange structure filled with the helium. The invention further discloses a pulse tube refrigerator adopting the deep hypothermic heat regenerator. According to the pulse tube refrigerator, the characteristic that the helium is high in volumetric specific heat capacity at low temperature is utilized, and the helium is closed in a certain space and used as the heat regeneration medium to exchange heat with helium used as a refrigerating working medium; the helium with the suitable pressure can be selected and charged into the enclosed space according to the work pressure of the pulse tube refrigerator so that the volumetric specific heat capacity of the helium serving as the heat regeneration medium in the deep hypothermic area can be higher than that of the helium serving as the refrigerating working medium, efficient heat regeneration can be achieved, and finally the performance of the pulse tube refrigerator in the liquid helium temperature area can be improved; meanwhile, compared with a magnetic heat regeneration material, the deep hypothermic heat regenerator adopting the helium as the heat regeneration medium has the advantages of being low in price, easy to obtain, free from influence of a magnetic field and the like.

A pulse tube refrigerator that is small in size and free from vibration and electric noise. A pulse tube refrigerator (1) has a pulse tube, a cool storage unit connected to the low-temperature side of the pulse tube, a vibration generator connected to the high-temperature side of the cool storage unit, and a reservoir with an orifice, connected to the high-temperature side of the pulse tube. The vibration generator is a thermally driven pressure wave generator having thermal drive tubes (heat exchangers (4-4a) for heat radiation), a phase shifter (7), and a return path (6). Sufficiently heating a heat exchanger (3) for heating causes self-exciting vibration to be generated in a work transmission tube (5), and work is returned to the thermal drive tubes through the phase shifter (7) and the return path (6) arranged on the work output side of the work transmission tube (5). The work is amplified by the thermal drive tubes, and is then outputted from the work transmission tube (5) and fed to the pulse tube refrigerator (1). A vibration generator for a pulse tube refrigerator that is small in size and free from vibration and noise can be realized.