STIRLING-TYPE PULSE TUBE REFRIGERATOR (PTR) DRIVEN BY COLD LINEAR COMPRESSOR

摘要

This research paper focuses on the study of the Stirling-type pulse tube refrigerator (PTR) system inrnconjunction with introducing cold compression concept. When the working fluid (helium) is compressed atrncryogenic temperature, the mechanical power (PV power) can be directly transmitted through the regeneratorrnto the pulsating tube without under-going unnecessary precooling process. The required PV power generatedrnby a linear compressor, furthermore, can be significantly diminished due to the relatively small specific volumernof the working fluid at low temperature. The PTR can reach lower temperature efficiently with higher heat liftrnat the corresponding temperature than other typical single-stage Stirling-type PTRs. Utilizing a cryogenicrnreservoir as a warm end and regulating the entire operating temperature range of the PTR will enable a PTRrnto operate efficiently under space environment. This research paper proposes the design methodology withrnnumerical computation (1D, axisymmetric) which considers the dynamic characteristics of the cold linearrncompressor with thermo-hydraulic governing equations for each sub component of the PTR. All the mass flowrnrates and pressures, as output parameters, are assumed to be sinusoidal, and then the thermal performance ofrnthe PTR is estimated in cooperation with the REGEN code. The experimental validation as a proof of conceptrnis carried out to demonstrate the capability of PTR operating between 80 K and 20 K. The linear compressorrnis submerged in a liquid nitrogen (LN_2) bath. No-load temperature of 23.2 K is recorded at the cold expansionrnvolume.