Finite Time Thermodynamic Optimization for Air Standard Thermal Power Cycles

Abstract

Considering the different specific heat models of working fluid, the performances of endoreversible and irreversible air-standard thermal power cycles, including Otto, Diesel, Atkinson, Brayton, Dual, Miller, Dual-Miller, Meletis-Georgiou and six-branch universal cycles, are optimized by using new branch of modern thermodynamics, i.e. finite time thermodynamics. The optimization objectives include the power (work) output, thermal efficiency, ecological function (the compromise between exergy output rate and exergy loss rate) and ecological coefficient of performance of the air standard cycle. The specific heat models include constant specific heat, specific heat varies linearly and nonlinearly with temperature of working fluid, and specific heat ratio varies linearly and nonlinearly with temperature of working fluid. The effects of specific heat models, design parameters and loss items on the optimal performances of thermal power cycles are analyzed. The results obtained in this book can provide theoretical guidelines for optimal designs of practical air standard thermal power cycles.