Research On Energy Conversion And Configuration Of Integrated Energy System

With the shortage of energy resources and increasing environmental pollution caused by the development of economy,it is very urgent to break the traditional energy system supply mode and improve the coupling degree among energy sources such as electric energy,heat energy and so on.Enhancing the comprehensive utilization efficiency of energy and achieving sustainable development between energy and environment become even more significant.Based on the concept of smart grid,the integrated energy system(IES)has received considerable attentions from various countries in recent years.The IES could improve the system energy utilization efficiency by coupling and collaborating different type of energies.It can also make up for problem of the energy fluctuation causing by the usage of renewable energy and promoting the development of renewable energy through the energy complementation and the energy storage devices.In addition,the reliability of the energy supply can be improved since the same form of energy demands can be supplied by multiple paths and converted among each other.To satisfy these advantages,it is necessary to study further on selecting the equipment in the integrated energy system and scheduling the energy during operation so that the cost problem can be reduced caused by the equipment redundancy and the energy utilization reduction and energy reliability issues produced by unreasonable energy flow distribution.Therefore,the researches about the energy conversion and configuration of integrated energy systems become significant to the development of IES.The paper mainly carried out the following aspects:First of all,this paper sorted out the structure of the system according to the concepts and definitions of the integrated energy system.The development status of the integrated energy system and the research status of energy conversion and configuration in the system has been summarized.Secondly,the necessity of energy conversion model in the planning of integrated energy system has been introduced and the energy conversion relationship of the commonly used energy conversion equipment has been summarized.After modeling and analyzing the energy conversion equipment in the system such as gas turbine,internal combustion engine,absorption chiller and waste heat boiler,the operating characteristics of the equipment were obtained.The energy supply and demand relationship of the IES is derived and the energy conversion equipment in the system has been classified and redefined.From simple to difficult,an energy coupling model has been established to make the relationship between the equipment and energy flow direction in the system become clearer.Thirdly,the economic indicators including equipment installation cost,operation and maintenance cost,and equivalent annual cost,as well as energy-saving indicator including energy utilization efficiency were given.Therefore,a systematic evaluation system was constructed.According to the system requirements,energy characteristics and the working characteristics of the equipment,the principles of energy conversion and configuration were proposed,classified and summarized so that the relationship between the principles was obtained.Finally,the energy coupling model proposed in this paper is applied to a park in northern China,and a typical integrated energy system model is carried out.The economic and energy utilization efficiency are taken as the goal,and the optimal planning principle proposed in this paper is used as the constraint.The particle swarm optimization algorithm is used to solve the equipment and the daily energy scheduling of the system.The examples verify the effectiveness of the model and method.