Finite-time exergoeconomic performance optimization for a universal steady flow irreversible heat pump model

Abstract

The finite-time exergoeconomic performance of a universal steady flow irreversible heat pump cycle model, which consists of two heat-absorbing branches, two heat-releasing branches and two adiabatic branches with the losses of heat transfer, heat leakage and internal irreversibility, is analysed and optimized by using the theory of finite-time thermodynamics. The analytical formulae for the heating load, coefficient of performance (COP) and profit rate function of the irreversible heat pump cycle model are derived. The optimal heating load, COP and profit rate characteristics are obtained by searching the optimal heat conductance distributions of the hot- and cold-side heat exchangers for a fixed total heat exchanger inventory. Moreover, analysis and optimization of the cycle performance are carried out in order to investigate the effects of heat leakage, internal irreversibility and price ratio on the performance of the cycle by using numerical examples. It is shown that the heat leakage changes the profit rate characteristics qualitatively, and internal irreversibility decreases the profit rate of the cycle quantitatively. The performance characteristics of the steady flow irreversible Diesel, Atkinson, Otto, Brayton, Dual, Miller and Carnot heat pump cycles are included in the universal results obtained herein.