English title

Utilization of combined heat and power (CHP) systems that simultaneously fulfill the electrical and heating energy
needs is considered as an effective strategy for management of energy demand and consumption. Overall
operational efficiency in excess of 70% is made possible, when these systems are utilized, and it is expected that
needs for both the demand and supply sides are met even under the condition of unsubsidized energy resources. In Iran, where there are energy subsidies for fossil fuel and electricity, utilization of CHP systems requires proper modeling and selection of system components. Due to the large fluctuations in the electrical and heating load during various heating and cooling seasons, it is necessary to investigate the performance of a CHP system so that the optimal operating point is determined. The review of literature shows that the majority of these systems are studies without the means for thermal energy storage. In this study, the objective is the determination of optimal operational point for a CHP System with thermal energy storage tank utilizing evolutionary programming methodology. The findings are compared with the case of a conventional alternative, where the electrical energy is purchased from local utility company and a heating energy is furnished by a conventional boiler. Based on the current utility costs, the results show that the operating cost of a CHP system is nearly 50% lower than that of the conventional alternative. Also, it is shown that the use of absorption chiller reduces dependency on purchased electricity and increases the efficiency of the CHP system.