Ecological optimisation of a generalised irreversible Carnot refrigerator for a generalised heat transfer law

Abstract

SYNOPSIS The optimal ecological performance of an irreversible Carnot refrigerator with losses of heat-resistance, heat leak and internal irreversibility, in which heat transfer between the working fluid and the heat reservoirs obeys a generalised heat transfer law Q α (Δ T)n, is derived by taking into account an ecological optimisation criterion as the objective function, which consists of maximising a function representing the best compromise between the exergy output rate and exergy loss rate (entropy production rate) of the refrigerator. Some special examples are discussed. A numerical example is given to show the effects of heat transfer law, heat leakage and internal irreversibility on the optimal performance of the generalised irreversible refrigerator. The results can provide some theoretical guidance for the design of practical refrigerators.