| The intermittent and fluctuating nature of renewable energy generation affects the stable operation of the grid,and in addition,the increasing peak-to-valley difference of the grid increases the difficulty of grid peaking.In order to promote the efficient use of renewable energy and relieve the overload of the grid,energy storage technology has received the attention of many scholars.Among various energy storage methods,compressed air energy storage(CAES)technology has the advantages of huge capacity and long operating life and has gradually become one of the most promising large-scale energy storage technologies.In recent years,advanced adiabatic compressed air energy storage(AA-CAES)technology has been well developed,and there are still many shortcomings in its thermodynamic analysis and economic evaluation,and the related research conducted can help promote the commercialization of CAES power plants.Therefore,this paper is based on a large-scale AA-CAES system,and the following parts of work are carried out:Based on the thermodynamic theory of AA-CAES system,a thermodynamic model of AA-CAES system close to the actual working condition is constructed.Based on the general model of AA-CAES system components,the thermodynamic model of energy storage system is established,and the thermodynamic parameters of TICC-500 project are selected for model validation and error analysis work.Based on the design of the power plant,a construction idea of AA-CAES power plant with salt caverns as gas storage equipment is provided,and a 300 MW AA-CAES system considering the actual gas physical properties,energy conversion equipment losses and flow resistance is constructed.The design scheme of the energy storage power plant system can provide design ideas in project planning and can assist in actual engineering design.Based on the 300 MW AA-CAES system,three types of thermodynamic cycle models,real,unavoidable and mixed cycles,were established.Conventional and advanced exergy analyses of the main components have been conducted,and the analysis of the influencing factors of the key system parameters,such as the working pressure of the gas storage salt cavity and the energy storage density,has been completed.The results of the advanced exergy analysis show that the first stage heat exchanger on the turbine(HEX3)has the greatest potential for improvement,and its avoidable exergy destruction accounts for 13.15%of the total exergy destruction of the system.In the influence factor analysis,the increase of compression ratio of the compressor and expansion ratio of the expander are both beneficial to improve the system heat recovery.In addition,increasing the compressor isentropic efficiency and heat exchanger efficiency are both effective in improving the system charging and discharging efficiency.The economic calculation model of AA-C AES system was established,the analysis of the impact of investment and operation cost on the system economy was carried out,and the system economy evaluation scheme was obtained.The whole life cycle assessment method and modular costing technique were used to calculate the system cost module,and the system revenue calculation was completed based on the electricity spot market policy.After proving the economic feasibility of the power plant,the sensitivity and feasibility threshold analyses were conducted separately.Finally,the economic feasibility of the power station at different powers was discussed.The results show that the power station investment and internal rate of return are greater than 8%of the engineering feasibility standard,proving that the power station has economic feasibility.And the selling price of electricity has the greatest influence on the economic index of the power station,and its ability to resist undesirable factors is the weakest.In the change of unit power,with the increase of unit power,the economic index of power station is greatly improved,which proves that the construction of high power unit can obtain better economy. |
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