Parametric study of miniature Stirling cryocooler for high temperature infrared detector with design refinement for SWaP configuration

Abstract

The ability to precisely control cooling temperature while meeting strict SWaP (Size, Weight, and Power) requirements makes miniature Stirling cryocoolers essential for contemporary high-operating temperature infrared detector systems. This study conducts a thorough parametric analysis of a miniature rotary Stirling cryocooler based on a one-factor-at-a-time approach, employing a semi-adiabatic thermodynamics model. The results show that fluid flow pressure loss accounts for the biggest power loss, while the regenerator conduction loss is the largest heat loss. Additionally, each micrometer of piston stroke and regenerator length has an impact on the cryocooler’s overall performance and compactness. Therefore, a feasible stroke of 1.8 mm and a regenerator length of 24.5 mm is determined for the cryocooler design. As operating speed increases, the cryocooler’s net refrigeration capacity rises linearly, potentially allowing smaller components for SWaP cryocooler design. However, fluid flow pressure and mechanical friction losses rise sharply. Furthermore, based on the ideal analytical results, a miniature rotary Stirling cryocooler with enhanced SWaP characteristics is designed, generating 0.68 W of net refrigeration with an actual input power of 4.28 W. The predicted coefficient of performance for the cryocooler is 15.85 % at a cooling temperature of 150 K, with a designed weight of 177 g. The cryocooler’s specific power of 6.3 and mass-specific cooling power of 0.004 are achieved, respectively, indicating relatively higher efficiency, as well as compactness and lightweight. The designed cryocooler is compared with other Stirling cryocoolers from the literature and exhibits good agreement.