An ejector-based cryogenic refrigeration system for cold energy recovery includes a first cryogenic refrigeration loop connected by a helium compressor and a cryogenic refrigerator and a second cryogenic refrigeration loop connected by the helium compressor, a regenerator, an ejector, a cold head of the cryogenic refrigerator, an end to be cooled and a pressure regulating valve. The cryogenic refrigerator is separated from the end to be cooled. The cryogenic refrigerator and the cryogenic helium cooling loop share a helium compressor, which improves the utilization efficiency of the device and reduces the cost. The ejector allows a part of fluids to circulate in the cryogenic loop, so as to maintain a required cryogenic condition, recover the pressure of the fluids, reduce the gas flowing though the compressor loop, and thus reduce the power consumption of the compressor.

A pulse tube cryocooler includes a pulse tube that includes a tube inner space, and an integral flow straightener that includes a flow straightening layer disposed to face the tube inner space so as to straighten a refrigerant gas flow from the tube inner space or into the tube inner space and a heat exchange layer formed integrally with the flow straightening layer outside the flow straightening layer with respect to the tube inner space so as to exchange heat with the refrigerant gas flow by contact with the refrigerant gas flow and is disposed at a low-temperature end and/or a high-temperature end of the pulse tube. The flow straightening layer includes a plurality of protrusions that protrude from the heat exchange layer toward the tube inner space.

The reversed single-working-medium vapor combined cycle of the present invitation belongs to the field of thermodynamics, refrigeration and heat pump, which are consists of ten processes: a heat-absorption and vaporization process 1-2 of the M.sub.1 kg of working medium, a pressurization process 2-3 of the M.sub.1 kg of working medium, a heat-absorption process 3-4 of the (M.sub.1+M.sub.2) kg of working medium, a pressurization process 4-5 of the (M.sub.1+M.sub.2) kg of working medium, a heat-releasing process 5-6 of the (M.sub.1+M.sub.2) kg of working medium, a depressurization process 6-3 of the M.sub.2 kg of working medium, a heat-releasing process 6-7 of the M.sub.1 kg of working medium, a pressurization process 7-8 of the M.sub.1 kg of working medium, a heat-releasing and condensation process 8-9 of the M.sub.1 kg of working medium, a depressurization process 9-1 of the M.sub.1 kg of working medium.

The disclosure relates to a cryogen-free cooling apparatus for cooling a sample, comprising a vacuum chamber, a first cooling device which is configured to generate a first temperature in the vacuum chamber to provide a main thermal bath, a second cooling device, which is in connection with a sample stage on which a sample is to be arranged, wherein the second cooling device is a solid state cooler which is configured to provide a second temperature to the sample stage, and wherein the second temperature is different from the first temperature, and a sample loading device which is configured to change the sample while operating the first cooling device and the second cooling device, wherein the sample stage is held in the vacuum chamber by a plurality of first fibers of low thermal conductivity such that the sample stage is thermally decoupled from the main thermal bath.

Techniques are disclosed for systems and methods to reduce the overall physical size of and mechanical vibrations within a cryocooler/refrigeration system configured to provide cryogenic and/or general cooling of a device or sensor system. A refrigeration system includes an annular linear compressor configured to generate a compression wave of working gas for the system. The annular linear compressor includes an annular cylinder head with a pressure plate and a neck protruding from one side of the annular cylinder head, a compressor housing configured to mate with the pressure plate and the neck of the annular cylinder head and form a sealed cavity therebetween, and an annular cylinder assembly disposed within the sealed cavity and about the neck of the annular cylinder head. The annular cylinder assembly includes an annular piston assembly disposed within an annular cylinder of the annular cylinder assembly.

A compact, low power cryo-cooler for cryogenic systems capable of cooling gas to at least as low as 2.5 K. The cryo-cooler has a room temperature compressor followed by filtration. Within the cryostat, four counterflow heat exchangers precool the incoming high-pressure gas using the outflowing low-pressure gas. The three warmest heat exchangers are successively heat sunk to three stages of a pulse tube to absorb residual heat from the slight ineffectiveness of the heat exchangers. The pulse tube cold head also absorbs loads from instrumentation leads and radiation loads. The pulse tube stages operate at around 80 K, 25 K, and 10 K. The entire system—cryo-cooler, drive and control electronics, and detector instrumentation, fits in a standard electronics rack mount enclosure, and requires around 300 W or less of power.

A pulse tube cryocooler includes a pulse tube; a bidirectional flow path that is connected to the pulse tube, and through which a pulse tube inflow and a pulse tube outflow alternately flow; a DC flow generator that is disposed in the bidirectional flow path, causes a first pressure drop in the pulse tube inflow, and causes a second pressure drop different from the first pressure drop in the pulse tube outflow; and a flow rate regulator that is disposed in the bidirectional flow path in series with the DC flow generator, and adjusts flow rates of the pulse tube inflow and the pulse tube outflow.

A Stirling cooler structure having multiple cooling modules includes at least one power unit, a pipeline, a plurality of Stirling cooling modules, and at least one piezoresistive unit. The power unit includes a cylinder and a piston. The pipeline is connected to the cylinder. The Stirling cooling modules each include a pipe and a passive displacer. The passive displacer is reciprocally, movably disposed in the pipe to partition the pipe into a cold end and a hot end. The hot end is connected to the pipeline. The piston is driven by an electric motor for a compressed air to flow through the pipeline to the hot end and then flow to the cold end through the passive displacer, such that the cold end absorbs ambient heat. The piezoresistive unit is selectively disposed between the Stirling cooling modules and the cylinder.

A Stirling cooler structure having multiple cooling modules includes at least one power unit, a pipeline, a plurality of Stirling cooling modules, and at least one piezoresistive unit. The power unit includes a cylinder and a piston. The pipeline is connected to the cylinder. The Stirling cooling modules each include a pipe and a passive displacer. The passive displacer is reciprocally, movably disposed in the pipe to partition the pipe into a cold end and a hot end. The hot end is connected to the pipeline. The piston is driven by an electric motor for a compressed air to flow through the pipeline to the hot end and then flow to the cold end through the passive displacer, such that the cold end absorbs ambient heat. The piezoresistive unit is selectively disposed between the Stirling cooling modules and the cylinder.

The disclosure relates to a cryogen-free cooling apparatus for cooling a sample, comprising a vacuum chamber, a first cooling device which is configured to generate a first temperature in the vacuum chamber to provide a main thermal bath, a second cooling device, which is in connection with a sample stage on which a sample is to be arranged, wherein the second cooling device is a solid state cooler which is configured to provide a second temperature to the sample stage, and wherein the second temperature is different from the first temperature, and a sample loading device which is configured to change the sample while operating the first cooling device and the second cooling device, wherein the sample stage is held in the vacuum chamber by a plurality of first fibers of low thermal conductivity such that the sample stage is thermally decoupled from the main thermal bath.