Optimisation of Low Temperature Difference Solar Stirling Engines using Genetic Algorithm

Abstract

This paper presents results of theoretical investigations on the determination of optimal design parameters of a Low Temperature Difference (LTD) Solar Stirling Engine using optimisation method based on Genetic algorithms. The developed thermodynamic mathematical model of the engine takes into account hydraulic and mechanical losses in the engine’s working process and this model was coupled to the optimisation algorithm. A set of such design parameters as the stroke of the displacer and diameter and stroke of the power piston and the thickness of the regenerator placed in the displacer have been considered as variables. The engine’s performance parameter such as the brake power is used as the objective function of the optimisation algorithm. The GA code is implemented in MATLAB. The accuracy of the optimal design engine’s performance is examined using 3D CFD modelling of the working process of the engine. The set of design parameters obtained from the optimisation procedure provides the noticeable improvement of the engine’s performance compared with the performance of the original LTD Solar Stilring engine with the same operating condition.