Construction, testing and performance analysis of a multi-stage traveling-wave thermo-acoustic generator

This research describes the construction and testing of a multi-stage thermo-acoustic generator that demonstrates the potential of conversion of waste heat into useful electricity. The total length of the traveling-wave loop was 3 560 mm. The thermo-acoustic engine stages were positioned 640 mm apart. An experimental investigation into the effects of the heat source on the potential of the device for electricity generation has been conducted. The magnitude of the sound pressure level generated by the engines, the onset time and the magnitude of electricity generated by the electroacoustic converter have been considered as performance indicators for the device developed. This paper provides details of the experimental investigation by measures of these indicators. A single-stage thermo-acoustic system, tested separately, generated an average output voltage of approximatively 834 mV. A second stage was added into the traveling-wave loop. The two-stage system generated an output voltage of approximately 1.55 V. A third stage was added into the loop. The three-stage system generated an output voltage of 2.362 V. The subsequently added four-stage thermo-acoustic system generated an average maximum output voltage of 4.218 V.