investigation of how to choose capacity of gas engine in optimization CCHP systems with GA; Case study: water sports complex

Energy, economic, and environmental analyses of combined cooling, heating and power (CCHP) systems were performed here to select the nominal capacities of equipment system with gas engine as prime mover for a water sport complex. The analysis was performed for both different scenarios (selling (Ss) and no-selling (SNs) electricity )from (to) grid to specify design parameters such as the number and nominal power of prime movers, heating capacities of both backup boiler and the cooling capacities of electrical and absorption chillers. By defining an objective function multi criteria called the Relative Annual Benefit (RAB), Genetic Algorithm optimization method was used for finding the optimal values of design parameters. Then, how to choose nominal capacity of gas engine has been investigated by considering the economical (RAB, PB) and fuel energy saving ratio (FESR) and environmental (CO2). The optimization results indicated that two gas engines (with nominal powers of 130 and 150 kW) in selling scenario(Ss) and one gas engine (with nominal power of 120 kW) in no-selling scenario(SNs), provided the maximum value of the objective function. Furthermore the results of the how selection gas engine show, in both two scenarios sell and No-sell electricity , if two similar capacity instead optimized capacities are selected, the payback period increases and annual benefit decreases, but the ratio of fuel energy saving and reducing of emission CO2 ratio, decrease in sell scenarios and increase in No-sell scenarios.