Employing a new optimization strategy based on advanced exergy concept for improvement of a tri-generation system

Abstract

Two multi-objective scenarios are carried out for optimization of a tri-generation cycle based on the conventional and also, the new exergetic and exergo-economic concepts. The optimization results of both scenarios are presented and compared in details. In the first scenario which is based on the conventional concept, for multi-objective optimization the objective functions are considered to be exergy efficiency and final production cost. In the second scenario the objective functions are modified on the basis of the new definition of exergy efficiency and final production cost according to advanced exergy concept. The purposes of the optimizations are maximizing exergy efficiency and minimizing final production cost using an evolutionary algorithm. The results show that total exergy efficiency after first and second optimization scenarios are increased about 7.4 and 9.9%, and final production costs are reduced about 24 and 26%, respectively. Although the final production costs are reduced for both of the scenarios, the total investment costs increase from 156.97 ($/h) for the base case to 205.04 ($/h) and 274.8 ($/h) for the first and second scenarios, respectively. In general, the obtained results justify the capability of the proposed strategy in further improving the system compared to the conventional method.