Dynamic and thermodynamic characteristics of the moving-coil linear compressor for the pulse tube cryocooler. Part A: Theoretical analyses and modeling

•Dynamic and thermodynamic characteristics of the linear compressor are analyzed.•An improved ECA model is built to study the cold finger and its influence on φ, ΔP.•Variations of φ, ΔP, I and θ with frequency at typical temperatures are simulated.•Compressor performance and cooler cooling performance are simulated and discussed.•Effects of compressor geometrical parameters on ηmotor are simulated and discussed.

Theoretical analyses and modeling are conducted on dynamic and thermodynamic characteristics of the moving-coil linear compressor in the Stirling-type pulse tube cryocooler. Governing equations are deduced, and φ and ΔP are found to be the two key parameters connecting compressor to pulse tube cold finger. An improved ECA model is developed to investigate the cold finger characteristics and their influences on φ, ΔP. Systematic simulations based on a specific case are performed to provide elaborate explanations about the theoretical analyses with the frequency varying from 30 Hz to 100 Hz at 60 K, 80 K and 100 K, respectively. The variations of four important parameters of φ, ΔP, I and θ, and the compressor thermodynamic performances and the cryocooler cooling performances, with the frequency at above temperatures are simulated and analyzed, respectively. The effects of compressor geometrical parameters on ηmotor are also simulated. The experimental verifications will be presented in Part B.