Abstract
We built and tested a double-loop thermoacoustic Stirling cooler. The cooler consists of a prime-mover loop, a branch resonator and a cooler loop. Work flow measurements were conducted to evaluate the efficiency of the cooler. It was found that efficiency corresponding to 6.6% of the Carnot efficiency was expected for the prime-mover loop, whereas a Carnot efficiency of 11.5% was expected for the cooler loop. Measurement of heat rejected by cooling water showed that unwanted heat loss significantly lowered the efficiency in the prime-mover loop. When the effective input heat to the regenerator was used to estimate the efficiency, the efficiency was found to be 20.4% of the Carnot efficiency, comparable to that of mechanical Stirling engines.
