The Performance Analysis And Optimization Of Compressed Air Energy Storage And Organic Rankine Cycle Integrated System

In the face of the rapid development of renewable energy power generation and the increasingly prominent problem of peak load regulation of power grid,compressed air energy storage,as one of the effective technical approaches,has become the focus of energy research at home and abroad.In this paper,aiming at the problem of low operating efficiency caused by energy waste in the system itself,a combined operation system（CAES-ORC system）of compressed air energy storage and organic Rankine cycle,which makes full use of waste heat of gas turbine exhaust to improve system efficiency,was proposed.According to the first and second laws of thermodynamics,the thermodynamic model of the system was established,and the simulation optimization was carried out by using ASPEN PLUS and Matlab software.The effects of equipment performance and state point parameters such as compressor,combustion chamber,gas turbine and evaporator on the thermal performance of the system were studied,and the system working fluid was selected according to various evaluation indexes.Finally,the process optimization of the different objective functions of the system and the performance optimization based on genetic algorithm were carried out.The results show that the evaluation indicators of CAES-ORC system are better than CAES system.The total system efficiency is higher when the compressor 1 intake air temperature and gas turbine exhaust pressure are lower,the combustion chamber exhaust temperature and pressure are higher,the evaporation pressure and the No.2 gas exhaust flow rate are larger.Different pressure ratios and distribution methods of compressors and gas turbines have different effects on the total efficiency of the system.When using R600 as the CAES-ORC system cycle working fluid,the system performance indicators are optimized.When the system corresponding pressure ratios Y_c1、Y_c2、Y_g11 and Y_g22 are 8,2,0.3,and 0.13,the process optimization makes the total system efficiencyη_ee reach a maximum of70.06%.The comprehensive performance of multi-objective optimization based on genetic algorithm is better than that of single-objective optimization.Under certain operating conditions,the CAES-ORC system realizes the cascade utilization of energy and provides theoretical support and engineering guidance for compressed air energy storage technology.The paper has 44 pictures,16 tables,and 57 references.