Multi-objective optimization and thermoeconomic analysis of a novel CCHP with TES and hybrid cooling for residential complex

Abstract

This paper proposes a novel combined cooling, heating, and power (CCHP) system integrated with thermal energy storage (TES) and a hybrid cooling system for a residential complex in Tehran for summer and winter. The use of thermal energy storage adapts the thermal load and the heat generated in the system. The strategy used is that when the thermal energy storage is fully loaded, the engine will be switched off and uses only the stored energy. Due to the inability to change the load on the absorption chiller, an electric chiller is used when the cooling load is greater than the absorption chiller capacity. The evaluation of the system from exergy and thermoeconomic viewpoint is done for the coldest and warmest days of the year concerning thermal and cooling loads of the residential complex. Then, multi-objective optimization of the system with exergy efficiency and total product cost rate is performed by NSGA II. The results of exergy analysis show that the highest exergy destruction ratio belongs to the boiler. This values in summer and winter were 66.4% and 48.2%, respectively also the maximum rate of destruction cost in both modes are absorption chiller and boiler with 1230 $/h and 159 $/h and the exergy efficiency in summer and winter are estimated about 14.3% and 33.9%, respectively. Optimization of the system is done for the warmest and coldest months of the year. The results show that the best trade-off system performance is on June 20 and January 11, moreover, exergy efficiencies for the two modes were 15.58%, 42.04%, and product cost rates were 265.74 $/h and 53.03 $/h, respectively.