Simulation and optimization of distributed energy system based on differential evolution algorithm

Many parameters can influence performance of a distributed energy system as it involves various kinds of equipment. Proper sizing of various equipment is of great significance for its efficient operation of such systems. This paper took a business district as the research object, predicted and analyzed the hourly cooling/heating load of the system during typical days of different seasons. Based on comprehensive consideration of the user’s usage pattern, load, equipment characteristics and other issues, gas engine was selected as the system’s prime mover, and the system structure was designed accordingly. Mathematical model was developed including gas engine, gas boiler, absorption chiller and other equipment. The differential evolution (DE) algorithm was applied to optimize the equipment capacity of the energy system, with the multi-objective of lower annual total cost and less annual emission. The annual pollutant emission of the plan C is the lowest in the results, which is more suitable for the business district. Compared with the traditional energy system, the annual total cost and pollutant emission of the optimized system were about 22% and 27% lower, respectively. The distributed energy system shows significant advantages.