Pulse tube refrigeration technology is a technology that uses pulsating air flow for refrigeration

Pulse tube refrigeration technology is a technology that uses pulsating air flow for refrigeration. Here's how:

Working principle

Pressure wave generation: high-frequency pressure waves are generated in the sealed gas path through the compressor and other equipment, so that the gas forms a periodic pulsating air flow in the vessel.

Gas expansion and compression: When the high-pressure gas enters the vessel, it appears laminar flow. During inflation, due to the temperature gradient formed by compression in the vessel, the temperature at the closed end is the highest, and the compression heat is taken away by the cooling water. When the high pressure gas in the vessel is evacuated, a low temperature cooling area is formed at the outlet end of the tube to achieve the cooling effect.

Main component

Compressor: Used to produce high-pressure gas, provide power to the system, so that the gas in the system circulation flow.

Reheater: usually composed of porous media, such as stainless steel wire mesh, copper wire mesh or shot, etc., the role is to store and release heat in the process of gas temperature change, improve the efficiency of refrigeration.

Cold end heat exchanger: provides cold capacity for low temperature environment, so that the heat of the cooled object or space is transferred to the refrigerant.

Vasa: An empty tube, a key component of refrigeration, in which fluctuating air currents produce temperature changes.

Hot end heat exchanger: Heat dissipation to the environment at room temperature, and heat generated by the refrigerant during the compression process is distributed to the outside world.

Small valve or phase regulating tube: used to adjust the phase of gas, control the flow and temperature distribution of gas in the vessel.

Gas storage: has a large closed volume, so that the system pressure remains relatively constant.

Technology type

Divided by drive mode

GM type: The use of GM compressor with valve to provide low-frequency pressure wave operation is the main method to obtain low temperature below 4.2K and provide large cooling capacity in this temperature zone.

Stirling type: provides high frequency pressure waves through valveless compressors, and with the development of related technologies, the electrical power conversion efficiency of compressors can usually reach more than 80%.

Thermoacoustic drive type: The pressure wave generated by thermoacoustic oscillation is mainly used to drive the vasculature, and the last moving part in the vasculature is removed, so that the device runs more reliably and has a longer life.

Divided by layout

Linear: the flow direction of the air flow from the regenerator to the vessel remains unchanged during the process, which is theoretically a more ideal arrangement, but it will increase the axial size of the refrigerator, and the pipeline layout and vacuum vessel structure are complicated.

Coaxial type: The hollow vessel is coaxial arranged in the center of the regenerator, the structure is compact, suitable for occasions with special requirements for space size, but the air flow has local bending resistance and reflux loss, and the heat exchange loss of the regenerator and the vessel through the common tube wall will also affect the performance.

U-type: between the linear and coaxial type, the axial size is about half of the linear, with good compactness, fluid flow from the regenerator through the U-type transition tube to the vessel, smooth transition, reflux loss is smaller than the coaxial type.

Application field

Cryotherapy: It can be used for cryosurgery, tissue cryopreservation, etc.

Semiconductor processing: Provides a low temperature environment for certain processes in the semiconductor manufacturing process, improving product quality and performance.

Aerospace: Used for cooling of infrared detectors, cooling of space exploration equipment, etc.

Quantum technology: provides a low-temperature environment for quantum devices such as superconducting quantum interferometers to ensure their normal operation and performance.

Liquefied natural gas: Thermoacoustic driven pulse chiller can directly use heat energy, liquefied natural gas with burning natural gas as a heat source.