Design and optimization of piezo-thermoelectric hybrid power generation in a small-scale thermoacoustic engine prototype

Abstract

[EN]This study aims to design, build, and optimize the performance of a small-scale thermoacoustic engine (TAE) prototype hybrid (piezoelectric/thermoelectric) power generation. Independent variables are predicted using the quadratic model, which are selected based on ANOVA analysis for best fit of experimental data. A Box-Behnken Design (BBD) is applied with 20 treatments. The independent variables considered for evaluation included run time (5–15 min), hot-side heat exchanger (HX) temperature (400–600 °C), resonator length (0.402–0.604 m), cold-side HX temperature (0–27 °C) and working gas (air, N2, CO₂). The results show that the hot-side HX temperature had a significant impact on the total output power (P total), whereas the cold-side HX temperature and resonator length had a relatively mild effect on P total. The working gas type and run time also do not have a significant impact on P total. The optimal conditions for a maximum P total of 65 mW were achieved using nitrogen (N2) as the working gas, under a hot-side HX temperature of 585 °C, resonator length of 0.518 m, and cold-side HX temperature of 2.025 °C. The good fit between experimental and predicted values under optimal conditions confirms the accuracy of the model. Results demonstrate this TAE potential for industrial waste heat recovery application, despite long-term material stability at high temperatures need to be further investigated.