A vertical support rigidly mounted to a planar base positions and supports a cryocooler expander unit off axis and away from a sample to be examined. The sample support is likewise rigidly mounted to the planar base with a rigidly mounted sample housing therein. The cryocooler expander unit is suspended in the vertical support by spring dampening bearings. A pair of opposing flexible vacuum bellows connects the cryocooler expander unit to the sample housing and vertical support. This configuration isolates the sample from vibration. Flexible thermal links associated with a predictive electronic closed loop control sequence maintains sample temperature.

The present invention provides a multi-stage double-acting traveling-wave thermoacoustic system, comprising three elementary units, each elementary unit comprises a linear motor and a thermoacoustic conversion device; the linear motor comprises a piston and a cylinder, the piston can perform a straight reciprocating motion in the cylinder; each thermoacoustic conversion device comprises a main heat exchanger and a heat regenerator connected in sequence, and the heat regenerator is of a ladder structure; a set of a non-normal-temperature heat exchanger, a thermal buffer tube and an auxiliary heat exchanger is connected at each ladder of the heat regenerator; and the main heat exchanger and the auxiliary heat exchanger of each thermoacoustic conversion device are connected to cylinder cavities of different linear motors respectively forming a loop structure for flow of a gas medium. The multi-stage double-acting traveling-wave thermoacoustic system can improve the working performance of the multi-stage double-acting traveling-wave thermoacoustic system.

The present invention provides a multi-stage double-acting traveling-wave thermoacoustic system, comprising three elementary units, each elementary unit comprises a linear motor and a thermoacoustic conversion device; the linear motor comprises a piston and a cylinder, the piston can perform a straight reciprocating motion in the cylinder; each thermoacoustic conversion device comprises a main heat exchanger and a heat regenerator connected in sequence, and the heat regenerator is of a ladder structure; a set of a non-normal-temperature heat exchanger, a thermal buffer tube and an auxiliary heat exchanger is connected at each ladder of the heat regenerator; and the main heat exchanger and the auxiliary heat exchanger of each thermoacoustic conversion device are connected to cylinder cavities of different linear motors respectively forming a loop structure for flow of a gas medium. The multi-stage double-acting traveling-wave thermoacoustic system can improve the working performance of the multi-stage double-acting traveling-wave thermoacoustic system.

A method for maintaining a refrigeration unit includes a connecting step of connecting a refrigerator body to a vacuum case with a first cooling stage in thermal contact with a radiation shield, where in the connecting step, the fastening force of the fastening member is adjusted such that the temperature of the first cooling stage becomes a target temperature.

A double-inlet valve for a Gifford-McMahon (GM) type double-inlet pulse tube cryocooler system for providing cooling at cryogenic temperatures includes a fixed restrictor and a needle valve coupled to the fixed restrictor in parallel. The needle valve produces asymmetric flow. The combination of the fixed restrictor and the needle valve having an asymmetric flow provides improved alternating current (AC) flow characteristics and adjustability of direct current (DC) flow to increase the available cooling.

Provided is a supercritical fluid chromatography system, and components comprising such a system, including one or more of a supercritical fluid chiller, a supercritical fluid pressure-equalizing vessel, and a supercritical fluid cyclonic separator. The supercritical fluid chiller and the use of the chiller allow efficient and consistent pumping of liquid-phase gases employing off-the-shelf HPLC pumps in the supercritical chromatography system using liquid-phase gas mobile phase. The pressure equalizing vessel allows the use of off the shelf HPLC column cartridges in the supercritical chromatography system. The cyclonic separator efficiently and effectively allows for separation of sample molecules from a liquid phase or gas phase stream of a supercritical fluid.

Provided is a supercritical fluid chromatography system, and components comprising such a system, including one or more of a supercritical fluid chiller, a supercritical fluid pressure-equalizing vessel, and a supercritical fluid cyclonic separator. The supercritical fluid chiller and the use of the chiller allow efficient and consistent pumping of liquid-phase gases employing off-the-shelf HPLC pumps in the supercritical chromatography system using liquid-phase gas mobile phase. The pressure equalizing vessel allows the use of off the shelf HPLC column cartridges in the supercritical chromatography system. The cyclonic separator efficiently and effectively allows for separation of sample molecules from a liquid phase or gas phase stream of a supercritical fluid.

Embodiments as disclosed herein are directed to a heat pump that employs at least two different refrigerants, each of which is optimized for either a cooling operation mode or a heating operation mode. The embodiments as disclosed herein can help increase the capacity and/or efficiency of a heat pump in both the cooling operation mode and the heating operation mode. In addition, the embodiments as disclosed herein may also eliminate the need for a ground source in a relatively low ambient temperature environment.

Embodiments as disclosed herein are directed to a heat pump that employs at least two different refrigerants, each of which is optimized for either a cooling operation mode or a heating operation mode. The embodiments as disclosed herein can help increase the capacity and/or efficiency of a heat pump in both the cooling operation mode and the heating operation mode. In addition, the embodiments as disclosed herein may also eliminate the need for a ground source in a relatively low ambient temperature environment.

A thermal management system includes at least one vapor compression system (VCS) that is configured to cool portions of the vehicle. The VCS circulates a fluid therethrough to cool the portions of the vehicle through heat exchange. At least one reverse air cycle machine (RACM) couples to VCS through a first heat exchanger. The RACM is configured to receive ram air. The RACM expands the ram air. Heat from the fluid circulating through the VCS is transferred to the expanded ram air through the first heat exchanger.