Optimum endoreversible power cycle with a specified operating temperature range

Abstract

An endoreversible power cycle can be seen as one in which two heat transfer processes and one work production process in series are sharing (and competing for) the same overall temperature potential. An optimal allocation of the temperature difference available from a heat source and a heat sink between these processes therefore results in a two dimensional search. It is found that, for the Curzon–Ahlborn (C-A) endoreversible power cycle, the maximum power occurs when the available overall temperature difference is shared equally between heat transfer and work production processes, and the specified overall heat conductance equally distributed between the boiler and the condenser heat exchangers. A more flexible optimization approach consists in analyzing the C-A power cycle within a larger family of endoreversible maximum power cycles defined with a specified operating temperature range for the working fluid as a parameter. This general optimization problem is solved as a one degree of freedom search and used to fit observed efficiency and temperatures of actual cycles to separate internal from external irreversibilities.