Finite time and finite speed thermodynamic optimization for an irreversible Atkinson cycle

Combining the finite piston speed thermodynamics and finite time thermodynamics and considering the irreversible losses caused by heat transfer, friction, finite piston speed and internal irreversibility, a more practical irreversible Atkinson cycle model is founded in the paper. When the finite piston speeds in cycle processes are not equal, choosing the ecological coefficient of performance, thermal efficiency, power output and ecological function as performance parameters, and choosing the piston speed ratio and finite piston speed as the design parameters, the relationships among the performance parameters and design parameters are obtained, and the influences of the finite piston speed and piston speed ratio on the performance parameters are presented. The research results show that it is necessary to consider the different piston speeds in each process. The designer can choose the corresponding ranges of design parameters to make the corresponding performance parameter reach the maximum value in practice. This work has a certain theoretical significance and can guide the practical design.