Prospective optimization of CCHP system under multi-scenarios

Combined cooling, heating, and power systems are widely studied and designed to enhance their techno-economic performance for reducing the cost and emission. However, the optimization often neglects the prospective variations in the natural gas price and the emission factor of the grid electricity in the future. The present study focuses on the comparisons among the optimization results under multi-scenarios, which are business-as-usual, sustainable development, projected, optimistic-natural-gas-price, and optimistic-grid-electricity-emission-factor scenarios. The multi-objective optimization is conducted based on the NSGA II method along with the technique for order preference by similarity to an ideal solution method. The simulation results show the opposite effects of the natural gas price and the emission factor of the grid electricity on the sizing results of the combined cooling, heating, and power system. Recognizing that the natural gas price and the emission factor of the grid electricity decline simultaneously under the investigated business-as-usual, the sustainable development, and the projected scenarios, the optimized capacities of the key devices do not show significant variations. Nevertheless, the resulting annualized total costs and equivalent CO2 emissions are significantly reduced under the these scenarios.