Experimental Study of a Miniature High Specific Power Thermoacoustic Stirling Generator

A highly efficient, portable power supply capable of delivering several hundred watts is in high demand for applications such as outdoor sports and emergency relief efforts. The external combustion thermoacoustic Stirling generator is a key technology for developing such power systems due to its fuel flexibility, high efficiency, compactness, reliability, and quiet operation. This paper presents a novel approach using a spiral tube hot-end heat exchanger to enhance combustion-alternating flow heat transfer performance and specific power. A 300-watt-class thermoacoustic Stirling power generation system is designed and constructed, leveraging impedance matching and combustion-heat transfer coupling. The system’s output characteristics are experimentally examined under varying operating conditions, and a comprehensive loss analysis is conducted. Preliminary experimental results show that the power generation system achieves a maximum output electrical power of 415 W at a flue gas temperature of 765◦C, with a corresponding thermoelectric efficiency of 13.9% based on the diesel calorific value. With an ultra-high operating frequency of 135 Hz and lightweight design, the generator body achieves a specific power of 112 W/kg, demonstrating significant application potential. © 2024 Science Press. All rights reserved.