Experimental investigation of piston-free expander accompanied by cold linear compressor

Abstract

This research focuses on the study of Stirling-type pulse tube refrigerator (PTR) in conjunction with a linear compressor that produces a mechanical power (PV power) at a ‘cold environment’ (‘cold’ means colder than ambient condition including cryogenic state.). The generated PV power is directly generated at cryogenic temperature and transmitted to the cold expansion volume without undergoing a precooling process. Implementing a cold reservoir as a heat rejecter and regulating the entire operating temperature range of the PTR under sub-atmospheric temperature will enable a PTR to operate efficiently under cold environment like space. The experimental investigation is conducted with the cold linear compressor operating at 80 K as a proof of concept; no-load temperature of 18.7 K is achieved. This PTR including the cold linear compressor is expected to be further optimized for the whole system operating between 80 K and 20 K at the resonant state. This paper describes both of the preliminary test results and further discussions for an ‘optimized’ PTR system.