Thermo-economic analysis and multi-objective optimization of a solar dish Stirling engine

Abstract

ABSTRACT Stirling engines operate in a variety of temperatures and the electric power production via dish Stirling systems could be considered as an appropriate alternative for high-temperature solar concentrator energy harvesting systems. To this end, by performing various studies and analyses on the engine, Stirling cycle, and heat exchangers while utilizing the solar energy as the input thermal energy of the Stirling engine, parameters with the highest effect on the output power and engine stability are detected and considered as optimization variables. In this case, output power, thermal efficiency, and economic evaluation are taken to be the three suitable objective functions for multi-objective optimization. Moreover, two optimization algorithms of MOPSO and SPEA/2 are introduced and applied for the first time for analyzing a dish Stirling engine. Finally, the optimization variable values before and after optimization, as well as the yielded improvement in the output power and thermal efficiency are presented, using LINAMP and TOPSIS techniques for optimum point selection. The optimization results show that the optimum conditions for three objective functions in case of three-objective optimization acquired by LINAMP and TOPSIS methods are 38.96, 0.2391, 0.3127 and 38.71, 0.2433, 0.3152 of P-η-F, respectively, acquired from optimization by SPEA/2 algorithm. However, single-objective optimization of each of the three objective functions optimized separately yields the values of (42.27, 27.51, and 0.3379) and (42.12, 27.62, and 0.3361) for MOPSO and SPEA/2 algorithms, respectively.