Numerical Modelling and Performance Optimization of a Wire Mesh Regenerator for Stirling Engine Based on Solar Energy

Abstract

The greenhouse gases and the decrease of fossil fuels stocks are the main elements to search alternative solutions. Stirling engine presents an outstanding solution to reduce the use of fossil resources since it has the ability to operate with a multitude of renewable energies thanks to its external combustion. In the present study, a thermodynamic modelling is carried out to study the influence of several parameters of wire mesh regenerator on the performances of Gamma Stirling engine powered by solar energy. The non-ideal adiabatic model is used in this paper and validated against experimental findings and numerical previous models. The study analyses Clapeyron diagram to calculate the work produced by the engine. In addition, a heat flow analysis is conducted in Stirling engine heat exchangers including the heater, cooler and regenerator. The results demonstrate the importance of using a regenerator in Stirling engine operation to reduce the heat input requirement. Furthermore, it is shown that the porosity greatly affects the performances of Stirling engine; its increase can improve the thermal efficiency up to 22.5 %. Hence, a porosity of 80% is adopted in the current study as optimum study. The regenerator length increase results in power and heat input diminution; consequently, an optimal length of 0.01 m provides 1294.97 W output power with a required heat input of 255.01 J. The variation of matrix wire diameter of Stirling engine regenerator is analyzed and the results indicate that the optimum diameter is 60 μm which allows the engine to provide an output work of 49.84 J.