For practical applications of a thermoacoustic system using factory exhaust heat or solar heat, it is necessary to decrease the onset temperature ratio. In a previous study, a cascade thermoacoustic system with a number of prime movers connected in series was examined. This system can be driven at a lower onset temperature ratio than a conventional thermoacoustic system with a single prime mover. However, there are some problems with this system: it cannot be driven continuously and its thermal efficiency is low. Therefore, a parallel thermoacoustic engine was proposed. In this study, we compared the onset temperature ratios and thermal efficiencies of three systems: a normal thermoacoustic engine with a single prime mover, a cascade thermoacoustic engine, and a parallel thermoacoustic engine with two prime movers. The results indicated the parallel thermoacoustic engine to be advantageous in terms of the onset temperature ratio and thermal efficiency.
2015 by The Acoustical Society of Japan