Optimal Design And Operation Characteristics Of Integrated Energy System With Organic Rankine Cycle And Energy Storage

Integrated energy system(IES)can adjust measures to local conditions,integrate the output of various renewable energy sources in the region,realize the complementary advantages of different energies,and thus improve the energy utilization efficiency of the system,which is of great significance to the environmental pollution and the increasing energy demand of th e society.However,due to the complex coupling mechanism of various energy devices in the integrated energy system,the influence of different devices on the system energy supply and system performance will be different,which brings severe challenges to the research on the operation optimization of the integrated energy system.Based on this,this paper studies the optimal design and operation characteristics of the integrated energy system with energy storage and solar energy.The main research contents are as follows:(1)Based on the operation characteristics and nonlinear efficiency characteristics of each energy equipment in the integrated energy system,the thermodynamic models of each equipment are established.Secondly,taking Beijing as the research object,the commercial building model is established by building energy consumption simulation software De ST,and the load characteristics of the commercial building in the typical year are obtained.Furthermore,K-means algorithm is used to cluster the load data of the typical year into typical day scenes,which provides theoretical basis and data support for the follow-up operation optimization research.(2)A novel IES-ORC-CAES system with advanced adiabatic compressed air energy storage system(AA-CAES),internal combustion engine,organic Rankine cycle(ORC)and other equipment deeply coupled is constructed.The compressed heat of AA-CAES is absorbed by the user’s backwater and the air on the energy releasing side is heated by flue gas,which simplifies the structure of AA-CAES,and realizes the cascade utilization of energy and diversified energy demand of users.Considering time-of-use electricity price,taking economy,environmental protection and energy efficiency as optimization objectives,a collaborative optimization method based on genetic algorithm is proposed,which can dynamically adjust the energy output of the system.The results show that compared with the system without AA-CAES,the annual operating cost,annual carbon dioxide emissions and annual primary energy consumption of IES-ORC-CAES system are reduced by 14.84%,13.06% and 11.69% respectively.The discharge capacity of AA-CAES in the peak load period of typical days in winter and summer respectively takes up 10.02% and2.73% of the electricity load of users on that day.In addition,the discharge capacity of ORC in a typical day in winter and summer is 0.18% and 0.63% of the electricity load of users on that day respectively.By adjusting ICE,AA-CAES and ORC together,the flexibility of system energy supply is realized,and the matching of electric heating ratio at source load side is improved.(3)Based on the IES-ORC-CAES system,a parabolic trough solar collector(PTC)is added.The heat generated by the parabolic trough solar collector is used to replace the heat of flue gas to heat the air on the energy release side of AA-CAES.The IES-PTC-CAES system is constructed and optimized by the collaborative optimization method proposed in this paper.The results show that compared with IES-ORC-CAES system,the annual operation cost and annual carbon dioxide emissions of IES-PTC-CAES system are reduced by 10.79% and 4.92% respectively.However,due to the low utilization efficiency of solar energy,the primary energy consumption of ies-ptc-caes system is higher than that of IES-ORC-CAES system.In addition,the parabolic trough solar collector heats the air on the energy release side of AA-CAES system,which improves the discharge capacity of the system.Compared with IES-ORC-CAES system,the electricity consumption of IES-PTC-CAES system is reduced by 29.33%,43.31% and 40.44% under the economic,environmental and energy efficiency targets,respectively.The thermodynamic analysis of IES-PTC-CAES system shows that because the discharge of AA-CAES system is not affected by the flue gas of internal combustion engine,and the heat transfer oil can provide more heat than the flue gas,the energy output of the improved system is more stable.