Dynamic performance analysis and optimization of dish solar Stirling engine based on a modified theoretical model

摘要

A modified theoretical model of dish solar Stirling engine was developed based on a Stirling cycle operating with finite shaft rotating speed and the energy balance equations at hot and cold ends. The convergence of solar receiver temperature and charged gas heat releasing temperature represent the stabilization of solar receiver and Stirling engine respectively, thus, to guarantee a steady operation of the overall system. Impacts of meteorological condition, operational parameter of Stirling engine on system performance were investigated and analyzed systematically. Results indicate that higher solar flux intensity improves system performance while wind deteriorates the system performance. With the input solar energy specified, optimal charged gas mass in Stirling engine exists corresponding to the maximal power output. More effective heater, regenerator and cooler contribute to better optimal system performance. Meanwhile, the charged gas mass optimized under the daily average solar flux intensity achieves the maximal mechanical work in a day with less computation. The maximal theoretical peak power output of 25 kW and overall efficiency of 44% are obtained as high performance heat exchangers are adopted and charged gas mass is optimized. (C) 2019 Elsevier Ltd. All rights reserved.