Study on the method of improving the input power of the linear compressor in a high capacity pulse tube cryocooler

Abstract

Working characteristics of a linear compressor affected the performance of a pulse tube cryocooler significantly. However, its input power and efficiency need to be analyzed together in the optimization of a cryocooler. In this study, the electrical and mechanical characteristics of a linear compressor have been investigated to show how to achieve a high input power and a high efficiency. The electrical analyses show that a high input power requires the current and the displacement reaches the maximum simultaneously at the mechanical resonant point. The mechanical analyses show how to adjust the mechanical resonant point to meet these requirements. Changing the compression volume is adopted and verified by experiments. While it changes from 19 L to 17 L, the input power increases from 6.8 kW to 9.6 kW and the efficiency decreases a little from 59% to 57%. The study is helpful to take advantage of a linear compressor.