Thermodynamic and heat transfer studies on solar Stirling engine

A solar Stirling engine has been considered for thermodynamic and heat transfer studies and analyzed its performance under the solar radiation conditions at the VIT University, Vellore. The performance of plant has been compared with five working gases to select a suitable working fluid for the Stirling engine. As per the results, helium has been selected as working gas to develop the performance characteristics. The influence of design conditions i.e. receiver gas temperature, engine maximum pressure and concentration ratio on performance of the plant has been developed. The receiver´s conduction, convection and radiation losses are predicted to find the solar concentrator receiver´s efficiency. The results show that the optimum receiver gas temperature is function of type working fluid, engine maximum pressure and concentration ratio. The plant efficiency and specific power output are 10% and 2.7 kW/liter of helium at 540 W/m² of solar direct normal irradiation (DNI).