Evaluation of cooling and thermal energy storage tanks in optimization of multi-generation system

Optimization of combined cooling, heating and power (CCHP) generation system using gas engine as prime mover is presented in this work. The main objective of this work is comparison of optimum four different configurations for storing heating and cooling loads. For this purpose, a CCHP plant with/without thermal energy storage (TES) and cooling energy storage (CES) tanks were investigated separately. Gas engine nominal capacity, nominal capacity of TES and CES tanks, electric cooling ratio and operational strategies of electrical and absorption chillers as well as the engine at each hour were considered as 52 design parameters. Then, Real Parameter Genetic Algorithm (RPGA) was used to find the optimum values of decision variables to reach the maximum total annual profit (TAP) for each case. It was investigated that the optimum TAP has been improved 9.48%, 5.19% and 2.23% by applying TES + CES tanks, compared with the None, TES and CES cases, respectively. In addition, it was obtained that a gas engine with the higher nominal capacity was selected in the case of TES + CES compared with the other studied cases. Furthermore, it was determined that the CES, TES and None cases were the best, respectively after the TES + CES case in term of TAP. Finally, verification model for energy conservation was presented with acceptable precision.