Applicability of Thermo-Acoustic Generators (TAGs) for Low Grade Heat Recovery and Power Generation

Abstract

This paper explains the heat recovery and power generation from thermo-acoustic effect, design and fabrication work of a thermo-acoustic generator (TAG) and, identifying the most crucial design parameters such as critical temperature difference, pressure wave amplitude, sound level and fluid velocity, to develop an efficient TAG. During this study, a TAG was fabricated with a quarter wavelength acoustic resonator, a ceramic core as the stack/porous media, a nickel chromium heating coil as the heat source, chilled water heat exchanger as the heat sink and a diaphragm as the linear alternator. Air was used as the working fluid of the TAG. By creating a temperature gradient across the stack, thermal energy can be converted into acoustic power and then in the linear alternator, acoustic power converts into electrical energy. During the experiments, it was found that the fabricated TAG was able to generate 19.22 W for 212.3 °C temperature difference across the stack while the intensity of sound is 116 dB.