Exergoeconomic performance optimization for a steady-flow endoreversible refrigerator cycle model including five typical cycles

Abstract

The operation of a universal steady-flow endoreversible refrigeration cycle model consisting of a constant thermal-capacity heating branch, a constant thermal-capacity cooling branch and two adiabatic branches is viewed as a production process with exergy as its output. The finite-time exergoeconomic performance optimization of the refrigeration cycle is investigated by taking profit rate as the optimization objective. The relations between the profit rate and the temperature ratio of the working fluid, between the coefficient of performance (COP) and the temperature ratio of the working fluid, as well as the optimal relation between profit rate and the COP of the cycle are derived. The focus of this paper is to search the compromised optimization between economics (profit) and the utilization factor (COP) for endoreversible cycles, by searching the optimum COP at maximum profit, which is termed as the finite-time exergoeconomic performance bound. Moreover, analysis and optimization of the model are carried out in order to investigate the effect of cycle process on the performance of the cycles using numerical examples. The results obtained herein include the performance characteristics of endoreversible Carnot, Diesel, Otto, Atkinson and Brayton refrigeration cycles. Copyright The Author 2010. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org, Oxford University Press.