Comparison of combined cooling, heating and power (CCHP) systems with different cooling modes based on energetic, environmental and economic criteria

Combined cooling, heating and power (CCHP) system is drawing great attention due to its energy-saving, environmentally friendly and cost-saving characteristics. Conventionally, CCHP system uses the water-LiBr absorption chiller to meet the cooling demand. In this paper, comparison of exhaust-gas-and-hot-water-driven absorption chiller (AC) and another three cooling modes, including AC combined with electric chiller (EC), AC combined with gas-fired absorption chiller (GFC), and AC combined with ground source heat pump (GSHP), is made. Optimization models for the four CCHP systems following the electric load (FEL) and following the thermal load (FTL) are proposed. The evaluation criteria include primary fossil energy saving rate (PFESR), carbon dioxide emission reduction rate (CDERR) and annual total cost saving rate (ATCSR) compared with the separation production (SP) system. Genetic algorithm (GA) is used to achieve the optimal solutions. A case analysis of a hypothetical commercial building in Shanghai is performed. Results show that the CCHP system with GSHP under FEL strategy has the best comprehensive performance, with PFESR of 0.2990, CDERR of 0.5278 and ATCSR of 0.1582. Finally, sensitivity analysis of climate, natural gas price and pool purchase price are performed.