Accurate estimation of temperatures in a cryogenic space cooled by a Stirling cryocooler

Abstract

The experimental analysis of cryogenic chambers coupled with Stirling cryocoolers has received scant attention in the research literature. This work provides a novel contribution by developing and experimentally validating an analytical model of the coupling to predict temperatures in the system. The paper unifies the Stirling cryocooler equation previously derived by Otaka et al. and the thermal-electrical analogy for the chamber. The analytical formula predicts steady-state temperatures in the chamber as a function of the system's controllable design and operational parameters. The model was validated with experimental data from 15 tests of an alpha-type Stirling cryocooler coupled with a thermal chamber. The resulting model showed an accurate prediction of temperatures with an average coefficient of variance of 5%, mean biased error of 2%, and R² value of 0.95. The findings are relevant because of the urgent need to learn how to control cryogenic spaces using electricity-based systems. Such spaces will be of high significance in the future because advanced solutions and products in biomedicine, electronics, computing and other fields use cryogenic spaces.