Exergetic, ecological and thermo-economic (3E) optimization of an absorption heat pump with heat resistance, heat leakage and two internal irreversibilities: Comparison

Abstract

The multi-objective optimization of a three-heat-reservoir absorption heat pump (THR AHP) is used mainly considering three objective functions: exergetic performance criterion (EPC), exergy-based ecological criterion (E) and thermo-economic criterion (F). Indeed, the exergy, ecological and thermo-economic criteria are highlighted analytically. This is done by using the law of convective heat exchanges between the working fluid and the different components and finite time thermodynamics analysis. This is to determine the optimum operating points of the system by minimizing exergy destruction rate, the environmental impact and the costs of capital and energy consumed. Also, the parameters taken into account influencing the performance of the absorption heat pump are the heat resistances, the heat leakages, the thermo-economic parameter and the two internal irreversibility factors in particular that between the evaporator-condenser assembly. However, the Flowchart optimization methodology made it possible to deduce that the system presents a significant advantage at the maxima of the F and the EPC criteria in terms of coefficient of performance. Nevertheless, the THR AHP presents a significant advantage at the maximum of the EPC in terms of exergy destruction rate and at the maximum of the E in terms of specific heating load and exergy output rate.