Design of a single orifice pulse tube refrigerator through the development of a first-order model

Abstract

A first order model for the behavior of a linear orifice pulse tube refrigerator (OPTR) was developed as a design tool for construction of actual OPTRs. The model predicts cooling power as well as the pressure/volume relationships for various segments of the refrigerator with minimal computational requirements. The first portion of this document describes the development of this model and its simplifications relative to higher-order numerical models. The second portion of this document details a physical implementation of the pulse tube and compares its performance to the predicted performance of the model. It was found that the model accurately predicted qualitative behavior and trends of the orifice pulse tube refrigerator, but that the predicted temperature difference was approximately five times higher than the measured temperature difference. It is believed that the model can be improved with provisions for flow choking as well as warnings for behavior outside of the accepted operating conditions.