A simplified dynamic model of split-type free-displacer stirling refrigerator

摘要

A simplified dynamic model of the split-type free-displacer Stirling refrigerator (SFSR) was derived in the present study. The dynamics model consists of two transfer functions: G{sub}(dp)(s) and G{sub}(ep)(s). G{sub}(dp)(s) describes the dynamic behavior of the displacer motion induced by the piston motion; G{sub}(ep)(s) describes the dynamic behavior of the expansion space pressure induced by the piston motion. It was found that the simplified model of G{sub}(dp)(s) consists of 5 poles, two integral poles (s{sup}2), 2 zeros and with time delay; the simplified model of G{sub}(ep)(s) consists of 4 poles, 2 zeros and with time delay. It was also found that operating a SFSR at the resonance frequency of the expansion space pressure or G{sub}(ep)(s) can obtain a better refrigerator performance.