Feasibility Study of an Automotive Thermoacoustic Refrigerator

Concerns regarding the environmental impact associated with the use of current vapour-compression refrigeration systems in automobiles have led to the investigation of alternative ‘green ’ technologies. Thermoacoustic refrigera-tion, an emerging ‘green ’ technology based upon the purposeful use of high-pressure sound waves to provide cooling, is the most promising replacement investigated so far. Thermoacoustic refrigerators use environmentally benign gases, are relatively simple and inexpensive to manufacture and can operate using a heat source, which leads to their appeal as a sustainable waste heat recovery device. In this paper, the feasibility of a thermoacoustic refrigerator driven by recovered heat from the waste exhaust gases of an automobile is investigated. Practical considerations and calculations incorporating typical performance characteristics indicate that an automotive waste-heat driven ther-moacoustic air-conditioner is potentially feasible and warrants further investigation. GLOSSARY OF TERMS AHX ambient heat exchanger AMR active magnetic regenerator ATAR automotive thermoacoustic refrigerator CFC chlorofluorocarbon CHX cold heat exchanger COP coefficient of performance COPr Carnot relative coefficient of performance GWP global warming potential HDTAR heat driven thermoacoustic refrigerator HHX hot heat exchanger TAR thermoacoustic refrigerator TE thermoelectric TEWI total equivalent warming potential VAR vapour absorption refrigeration VC vapour compression VMAC vehicle magnetic air conditione