Acoustic-Mechanical-Electrical (AcME) coupling between the linear compressor and the Stirling-type cryocoolers

Abstract Benefitting from invention of linear compressors, Stirling-type cryocoolers have been experiencing rapid development due to its’ compact structure and high reliability. However, the efficiency of cryocoolers still needs to be improved to meet the requirements of long-term space exploration. A state point named ‘sweet spot’ is proposed after analyzing the output characters of linear compressors, and the ‘sweet spot’ corresponds to a state when the highest efficiency and the maximum power output are achieved simultaneously. Acoustic-Mechanical-Electrical (AcME) coupling between linear compressors and cryocoolers is established by combining the dynamics of the piston and the displacer with the thermodynamics of regenerative cryocoolers. Two cases are provided to verify that the AcME coupling theory is a useful tool for designing and optimizing cryocoolers. Mismatching between the linear compressor and the cold finger is discussed, and some possible extra impedance matching methods are introduced based on the electrical impedance matching network.