| In order to deal with the energy shortage and serious pollution in today’s society,improving the utilization rate of energy has become the theme of energy development in today’s society.As one of the solutions,the integrated energy system has developed rapidly,and the energy coupling of the system is becoming more complex.The complex situation of the transformation and transmission of various energy flows following different physical laws has brought great challenges to the comprehensive analysis of the system.Therefore,this thesis puts forward an effective model and method for the dynamic analysis and evaluation of the system for the comprehensive utilization rate of energy.The main contents of this thesis are as follows:(1)Establish the unified transmission theory according to the comprehensive energy system.Based on the law of conservation of energy and the law of conservation of momentum which is obeyed by energy flow,observe the overall regular pattern of power system,thermal system and gas system And analyze them based on the form of energy flow transfer equation in power system,so as to establish the unified mathematical equations for the current transfer,gas flow transfer and heat flow transfer.Based on the unified transfer equation of energy,a unified energy transfer model is established for pipeline system.The unified model and equation of muti-energy flow between the microchannels are realized by modeling and deriving of other essential components in the gas network and the thermal network except for the pipeline.(2)Based on the unified energy transfer equation analysis.In order to reduce the difficulty of network analysis,the vector method in the field of electric power is used to transform the branch transmission equation into Fourier transform,and the partial differential equation is simplified to ordinary differential equation,so that the transmission equation can be applied to the network branch and a branch model with unified energy is established.The branch node is analyzed,and the branch model is extended to the network model,so that it can be applied to the comprehensive energy system,and the dynamic analysis based on the network model is carried out.(3)According to the flow of energy,the overall structure of the integrated energy system is analyzed,and the internal energy flow model of the integrated energy system is established,which takes into account the multi energy input and multi energy output,describes the energy coupling form,and analyzes the generation,transformation,transmission and consumption of energy,and establishes the model to distinguish between "quantity " and "quality" of energy.According to the shortcomings of the existing evaluation indexes,a new comprehensive energy efficiency index ηies is proposed to judge the energy efficiency of the static system.(4)Based on the unified energy theory,the coupling link of the integrated energy system is analyzed,and the whole model of the system is completed,and the dynamic analysis of the system is made based on the model.Based on the comprehensive energy efficiency evaluation index ηies judges the dynamic state of the system,and proves that the index can make an accurate response to the variables in the complex system,and make a judgment on the renewable energy of the input system,more accurately and quickly judge the quality difference of the system output energy,and quickly respond to the energy usage efficiency of the system. |
