Finite-time exergoeconomic performance analysis and optimisation for generalised irreversible combined heat pump cycles

Abstract

Finite-time exergoeconomic performance of a Newtonian heat transfer law system generalised irreversible combined heat pump cycle model with irreversibility of finite-rate heat transfer, heat leakage and internal irreversibility is studied in this article. The operation of the generalised irreversible combined heat pump cycle is viewed as a production process with exergy as its output. The performance optimisation of the cycle is performed by taking profit as the objective. The optimal profit rate, optimal coefficient of performance (COP), as well as the relation between the optimal profit rate and COP of the cycle are derived. The focus of this article is to obtain the compromise optimisation between economics (profit rate) and the energy utilisation factor (COP) for the cycle, by searching the optimum COP at maximum profit rate, which is termed as the finite-time exergoeconomic performance bound. Moreover, the effects of various factors, including heat leakage, internal irreversibility and the price ratio, on the profit rate performance of the cycle are analysed by detailed numerical examples.