Abstract
Performance characteristics of a 1kW-class Stirling engine generator in helium working fluid were investigated to obtain the reference data for simulation and to find out the component for improvement. The experiments were carried out varying mean pressure from 2.4MPa to 3.3MPa, engine speed from 600rpm to 1400rpm and expansion space gas temperature from 723K to 873K. While expansion space work and compresion work increased in proportion to the mean pressure and with the increase of expansion space gas temperature, the output power showed no dependence on the mean pressure. The investigation on mechanical loss and internal thermal loss showed that the mechanical loss increased linearly with the mean pressure and the internal thermal loss significantly increased above the mean pressure of 2.9MPa, leading to the conclusion that the inclination of these losses caused the saturation of thermal efficiency against the increase of the mean pressure.
