Optimization For The Operation Strategy Of Distributed Energy System

With the rapid development of economy, China’s energy consumption increases continuously, which causes serious energy shortage problem and makes energy conservation and emission reduction situation more and more severe. In order to achieve economic development and accomplish the target of energy conservation and emission reduction at the same time, China has to explore new model of energy utilization, promote low-carbon economy by improving energy utilization efficiency and optimizing energy structure. Natural gas is the known clean energy of high quality, increasing its proportion in primary energy structure helps to relieve the pressure of energy conservation and emissions reduction. As a new energy-saving technology to use natural gas, DES(Distributed Energy System) has captured wide attention because of high energy efficiency and remarkable effect on energy conservation and emissions reduction. However, some technical problems have arisen along with the development of DES, of which the installed capacity and operation strategy of system are the most important problems. The rationality and reliability of both installed capacity and operation strategy can greatly influence the efficiency, the economic and environmental performance of DES.To make the best of DES, the idea to establish optimization model for operation strategy of DES is proposed in the paper based on the existing theory. The optimization principle for operation strategy can ensure that every hour the energy supply can match the energy demand perfectly. Based on this principle, choosing the hourly load demand of end users at typical day and the unit type of different systems as input parameters; using comprehensive evaluation index PFI(Performance Factor Index) as objective function, which takes into account the annual cost, primary energy utilization efficiency and carbon dioxide emissions; taking hourly energy balance between supply and demand of end users, supply ability of all equipment in the system as constraints conditions, the paper establishes the optimization model for operation strategy and programs the detailed algorithm of the model with MATLAB.According to the detailed algorithm of the model, the best energy supply scheme of DES which can meet the cold, heat and power demand of end users in the CBD of Zhengzhou is calculated. The results reveals when the installation proportion is 70% of the peak cold load, the DES system has the best installed capacity and the most reasonable operation strategy. Compared with traditional energy system, DES at the best operation strategy can reduce the annual energy consumption by 23.4%, reduce the carbon dioxide emissions by 43.0% and raise the energy efficiency from 0.62 to 0.81. It is obvious that the efficiency, the economic and environmental performance of energy system has been improved greatly, which further proves the practicability of the optimization model.