Performance Analysis And Optimization Of An Integrated Energy System Considering Carbon Dioxide Capture

With the rapid development of distributed energy technology and the increasing demand of integrated energy services,the integrated energy system has become an inevitable way of energy cascade utilization due to its high energy efficiency,low cost,environmental friendliness,flexibility and reliability.Various traditional and renewable energy technologies are included in the system for energy synergistic transformation among electricity,heating and cooling,etc.,to maximally meet the energy demand of end users.Due to the high volatility of the renewable energy on supply side and the load demand on demand side,the system presents a complex dynamic stochastic characteristic and uncertainty,which adds to a series of challenges in the design,operation,and optimization of the system.In addition,it is necessary to comprehensively consider the impact of carbon capture technology and the penetration of renewable energy on the improvement of system planning,operation and emission characteristics,as well as to analyze the low-carbon development mode of the integrated energy system,and to explore its new aspects such as system planning,operation,and market transactions.The economic,low-carbon and efficient operation of integrated energy system depends on the system-level optimal design and operation management.Moreover,it is of great significance to investigate the carbon emission transfer in the processes of system coupling and energy conversion,as well as to determine the optimal operation potential of integrated energy system from the perspective of low carbon development.Therefore,this thesis aims to analyze and optimize the comprehensive performance of integrated energy system with particular focus on the impact of CO2 capture technology on the overall economic,environmental and energy efficiency performance of the system.At the same time,considering the complementary time-sequence characteristics of load,distributed capacity and energy storage devices,based on the analysis of carbon capture technology and related carbon policy sensitivity,the optimal technology combination,installed capacity and operation strategy of the system under different scenarios will be determined,which will provide theoretical guidance and decisionmaking support for the optimal design and low-carbon operation of the integrated energy system.The main contents are organized as follows:The first chapter will introduce current status of China’s carbon emissions reduction policies and technologies,and will review on the integrated energy systems and carbon capture technologies which can improve energy efficiency and reduce carbon emissions.Based on mathematical programming and optimization modeling methods,the second chapter will establish an optimization model of integrated energy system considering carbon dioxide capture technology.Key parameters and constraints such as energy balance,investment and operation cost,and carbon emission characteristics of related equipments will be analyzed,aiming to minimize the total investment and operation cost and to define the relevant evaluation indicators of the system.The third chapter will analyze the integrated energy system with coal or gas fueled of prime movers through sensitivity analysis of the carbon emission reduction policy.Two types of carbon capture technologies,i.e.,post-combustion capture technology and oxy-fuel combustion technology will be evaluated.The optimal technology combination,installed capacity and operation strategy of the integrated energy system will be obtained via solving the optimization model.The fourth chapter will be focused on the analysis of Allam cycle,which is one of the improved oxy-fuel combustion technologies.Based on process simulation,the Allam cycle will be modeled,and the integrated energy system with Allam cycle will be optimized and analyzed through detailed performance simulation.The sensitivity analysis of key parameters under the constraint of carbon tax will be performed as well.The last chapter will summarize the major conclusions of the thesis,and to describe the next step research plan.