Numerical analysis of free-piston stirling cooler systems for improving cooling performance

Abstract

Free-piston Stirling coolers (FPSCs), where the spring is connected to a piston instead of a crankshaft to eliminate the complicated mechanism, have a simple structure, and exhibit high thermal efficiency and reliability. The present study conducted a numerical analysis of the cooling performance of the FPSC system for various design factors such as the wire mesh number and porosity of the regenerator and displacer clearance. The system analysis model using the commercial SAGE software was established for heat exchangers with wire meshes. Also, this study investigated the effect of the cooling temperature at the acceptor wall on the cooling performance under the optimal condition. It was found that as the wire mesh number and porosity of the regenerator increased, the cooling capacity of the FPSC decreased. The friction loss decreased, but the leakage loss increased with the increase in displacer clearance thickness.

Keywords

• Free-piston stirling cooler (FPSC)
• Cooling performance
• Regenerator
• Displacer clearance
• Cooling temperature