Development of a 187 K free-piston Stirling cryocooler with wound wire mesh regenerator

Abstract

Stirling cryocoolers are widely used in low-temperature storage because the advantages such as high reliability and efficiency. To meet the demands of commercialization, the production process of Stirling cryocoolers needs to reduce costs. Compared to stacked wire mesh regenerator, wound wire mesh regenerator has emerged as a new option to reduce the cost of regenerators, as it eliminates the need for manual filling of regenerator matrix and consumes less metal. In this manuscript, an investigation is conducted focusing on the characteristics of this wound wire mesh regenerator. To cool the −86℃ ultra-low temperature refrigerators, a free-piston Stirling cryocooler with a wound wire mesh regenerator was developed, and one-dimensional simulation and experiments were conducted on the cryocooler. To better optimize cryocooler design, theoretical research was conducted on refrigeration losses of cryocooler. Analysis and simulation of the theoretical and actual energy flow distribution in the cryocooler were conducted. The proportion of internal losses for different components was analyzed. Simulations were performed to investigate the impact of on internal losses within the regenerator and the refrigeration efficiency of the cryocooler, working parameters and cold end temperature. The simulation results were experimentally validated, and the performance of the cryocooler was tested in terms of cooling characteristics and operational stability. The prototype of the optimized cryocooler design achieved a cooling capacity of 120 W@187 K, with a minimum attainable cold end temperature of 121.1 K.