Optimal ratios of the piston speeds for a finite speed endoreversible Carnot heat engine cycle

Abstract

The performance of an endoreversible Carnot heat engine cycle is analyzed and optimized using the theory of finite time thermodynamics based on Agrawal and Menon's$^{i}$ model of finite speed of the piston on the four branches and Curzon and Ahlborn's$^{ii}$ model of finite rate of heat transfer. The finite speeds of the piston on the four branches are further assumed to be different, which is unlike the model of constant-speed of the piston on the four branches. The analytical formula between power and efficiency of the cycle is derived for a fixed cycle period. There exist optimal ratios of the finite piston speeds on the four branches. The effects of the temperature ratio of the heat reservoirs on the dimensionless power versus efficiency of the cycle and isothermal expansion ratio are obtained by numerical examples.