Numerical Investigation of Working Fluid Effect on Stirling Engine Performance

The Stirling engine is achieving great concern in the actual energy area since it has many advantages such as its cleanness and quietness. It is also considered a flexible prime mover for useful for several applications such as micro- cogeneration, solar thermal generation and other micro-distributed generation conditions. Theoretically, the Stirling cycle engine can efficiently convert heat into the mechanical work at the Carnot efficiency. The importance of the choice of working fluid is also demonstrated in the literature. In fact, the Stirling engine power can be increased ten times by changing the working fluid from air to hydrogen for example. This paper represents an evaluation of the on working fluid of a solar-dish Stirling heat engine. Thermal efficiency, exergetic efficiency and the rate of entropy generation corresponding to the optimum value of the output power are also evaluated. Numerical results demonstrate that the swept volume ratio is independent of the choice of working fluid.