Evaluation and optimization of a multi-effect evaporation–absorption heat pump desalination based conventional and advanced exergy and exergoeconomic analyses

Abstract

In order to increase knowledge regarding the improvement potentials and optimization of desalination process, this study evaluates conventional and advanced exergy and exergoeconomic analyses for a multi-effect evaporation–absorption heat pump (MEE–ABHP) desalination system. Advanced exergy and exergoeconomic analyses were each conducted to identify the components with the greatest influences and evaluate the realistic economic improvement potential of the system. Two new objective functions including, overall avoidable exergy destruction (OAD), and overall avoidable cost rates (OAC) of the system which are obtained by advanced exergy and exergoeconomic analyses, respectively, were considered for optimization of the system. Parameter optimizations were achieved using genetic algorithm (GA) for each objective functions to find the optimal operation conditions with minimization of the overall avoidable exergy destruction and cost rates of the system, separately. Further the unavoidable conditions were split into unavoidable technical and unavoidable economical conditions to find the influence of technical and economical limitations on the system performance. Overall, it was found that the best optimal operation conditions can be achieved by minimization of OAC, since the corresponding optimal system can decrease the total product cost rates by 33.33% and increase the exergy efficiency by 4.75% compared to the base system.