Study Of Regional Energy System Planning Based On Graph Theory

With the aggravation of the energy crisis and increasingly prominent issue of climate change,regional energy system plan is a frontier subject in the field of the research on low-carbon city construction in the present,relating to the complex issues involving national energy policy,national economy,energy technology,etc.Regional energy system is an applicable method in the pursuit of rational,scientific and efficient utilization of energy.A regional integrated energy system has been suggested to comprehensively plan every kind of available energy in the design area.A joint energy station is established to supply demand users with cold and heat through a transmission and distribution network.However,the planning strategy used in the primary stage of regional energy system establishment is a significant step,whose rationality will greatly affect the economic and environmental benefits of the system.Regional energy system plan is the science of synthesizing multi-energy application,load forecast on the demand side,network layout optimization and cost benefit analysis.A problem in any part of this process may result in energy inefficiency or fail to conserve energy and reduce emissions.However,sound planning guidance mechanisms for the regional energy system haven't been established or completed,and the relevant criterion is lacking.Therefore,this paper has a deep discussion and analysis of the basic prophase work for regional energy system construction,hoping to provide effective guidance suggestions for the construction of the system and provide a scientific and effective research program for the national sound system construction norms.Aiming at the preliminary planning work of the regional energy system construction,a systematic plan that includes three steps: regional resource status analysis,regional load forecast,and system layout optimization economic model calculation and analysis is proposed in this paper.A regional energy system mainly consists of energy stations,transmission and distribution networks,and users.Firstly,from the perspective of evaluation standard and decision maker,the resources condition in the region was comprehensively analyzed to determine the schemes of cooling and heating source with unit area index method and software numerical simulation method.Secondly,the main impact factors and features of regional load forecasting was analyzed,and a regional load forecasting method was put forward to propose the design basis for system configuration and equipment selection.Thirdly,a graph theory-based mathematical optimal model was established with the lifetime costs of the whole system as the economic goal,and an improved Prim algorithm was put forward to solve the costs of the transmission and distribution network with the dynamic weight set of pipeline flow.The model was solved by an algorithm based on the idea of a dynamic minimum spanning tree and optimal path planning.Lastly,the model and method were applied in a China–U.S.low-carbon demonstration city to verify feasibility and validity.The simulation results could help us to comprehensively integrate regional energy and accurately plan future cities.It also showed that the method for preliminary overall planning of regional energy system played a good role in guiding the optimal allocation of system facilities and could provide a reference for regional energy system development planners.