Power and Thermal Efficiency Optimization of an Irreversible Steady-Flow Lenoir Cycle

Using finite time thermodynamic theory, an irreversible steady-flow Lenoir cycle model is established, and expressions of power output and thermal efficiency for the model are derived. Through numerical calculations, with the different fixed total heat conductances ([Formula: see text]) of two heat exchangers, the maximum powers ([Formula: see text]), the maximum thermal efficiencies ([Formula: see text]), and the corresponding optimal heat conductance distribution ratios ([Formula: see text]) and ([Formula: see text]) are obtained. The effects of the internal irreversibility are analyzed. The results show that, when the heat conductances of the hot- and cold-side heat exchangers are constants, the corresponding power output and thermal efficiency are constant values. When the heat source temperature ratio ([Formula: see text]) and the effectivenesses of the heat exchangers increase, the corresponding power output and thermal efficiency increase. When the heat conductance distributions are the optimal values, the characteristic relationships of [Formula: see text] and [Formula: see text] are parabolic-like ones. When [Formula: see text] is given, with the increase in [Formula: see text] , the [Formula: see text] , [Formula: see text] , [Formula: see text] , and [Formula: see text] increase. When [Formula: see text] is given, with the increase in [Formula: see text] , [Formula: see text] and [Formula: see text] increase, while [Formula: see text] and [Formula: see text] decrease.