INVESTIGATION ON DYNAMIC BEHAVIOR OF LINEAR COMPRESSOR IN STIRLING-TYPE PULSE TUBE REFRIGERATOR

Abstract

This paper describes the experimental study of the dynamic behavior of a linear compressor in a Stirling-type pulse tube refrigerator (PTR). The dynamic behavior of the piston is closely coupled with the hydraulic force of gas and, therefore, directly influenced by the specific load condition of the pulse tube refrigerator. In the experiment, the frequency response of the pressure at each component, the cooling performance and the piston displacement are measured while an alternate current with fixed magnitude is supplied to the linear motor. The linear compressor in this study was originally designed for a Stirling cryocooler and its maximum input power is approximately 200 W. The pulse tube refrigerator is configured as an in-line type and an inertance tube is incorporated as the phase control device in the pulse tube refrigerator. The pressure difference between both ends of the piston imposes additional stiffness and the PV power in the compression space can be considered a damping effect in the vibration system of the piston. From the experimental results, the effect of the gas force on the dynamic behavior of the piston is discussed. The dynamic relation among the input current, the displacement of the piston, the pulsating pressure and the cooling performance is also studied.