Optimized Configuration of Cooling Source in Districted CCHP System: A Case Study in Guangxi

摘要

This study has the objective to study the optimized configuration of cooling source of a districted natural gas Combined Cooling Heating and Power (CCHP) system, and as a result, models of cooling source, distribution and system energy efficiency were established. Through a C# program, hourly simulation of operation quantity, power consumption, and equivalent thermal coefficient (ETC) of the cooling system during May to October was conducted under three configuration strategy schemes. The results revealed that when the waste heat of CCHP system was properly utilized, increasing the number of electric chiller could increase primary energy utilization rate. Scheme One with the most electric chiller units (15 units) consumed the most power, but had the highest ETC of 1.031 (mean),which was, respectively, 0.268 and 0.346 higher than that of Scheme Two with 11 electric chiller units and Scheme Three with most steam BrLi absorption chiller units (nine units). Scheme Three needed the most steam which led to the least electricity generated. Although in this scheme, the electric chillers consumed the least power, the average remaining electricity of the CCHP system was the lowest (64,992.4 kWh), which was 21,441.9 and 6,233.8 kWh less than that of Scheme One and Scheme Two. ETC of the three schemes (1.031, 0.763, and 0.685, respectively) were much less than that of electric chiller (2.630), which meant that the main reason for the decrease of primary energy utilization rate of the cooling system was due to low primary energy utilization rate of the distribution system.