| In recent years,with the continuous promotion of China’s energy structure transformation,renewable energy represented by wind power and photovoltaic has achieved rapid development,while also posing significant challenges to the stablility of the power grid operation.Electric energy storage technology is believed to be an effective means to achieve the safe and stable operation of the power grid and a large amount of renewable energy consumption,thus receiving extensive attention.With the advantages of large energy storage capacity,cleanliness and pollution-free,and good safety,compressed air energy storage(CAES)technology is regarded as an essential development direction in the future of the energy storage industry.An existing limitation to the rapid advancement of CAES technology is the disadvantagement of the low system efficiency,with the system efficiency lower than that of the conventional battery energy storage technology and the pumped storage technology.In order to improve the CAES system performance,this paper presents the coupling of advanced adiabatic compressed air energy storage system(AA-CAES)with the heterogeneous energy system,and explores the system integration mechanism.The paper first developed a thermodynamic model of the AA-CAES system and analyzed the overall performance of the system through the thermodynamic evaluation indexes based on the thermodynamic analysis method,thus revealing the energy consumption characteristics of the system.Based on the principle of physical energy cascade utilization,the paper proposes a coupling integration mechanism for AA-CAES systems based on heterogeneous energy complementarity and spatiotemporal coupling,providing theoretical support for the subsequent coupling of the AA-CAES system with the heterogeneous energy system.To effectively utilize the waste heat of the AA-CAES system,the integration of the heat regenerative system in the coal-fired power plant and the AA-CAES system is proposed.Condensate and feedwater from the heat regenerative system are used to recover and release the compression heat from the AA-CAES subsystem in a cascade,and condensate is used to recover the waste heat from the exhaust air of the AA-CAES subsystem.Through the system integration,it not only realizes the energy cascade utilization and improves the efficiency of the AA-CAES subsystem;but also reduces the heat and cold storage equipment,thus reducing the equipment investment cost.The performance of the coupled system is analyzed,and the results show that the round-trip efficiency of the AA-CAES subsystem is increased from 63.81%to 64.82%,and the exergy efficiency is increased from 63.76%to 68.02%.In addition,the dynamic payback period of the AA-CAES subsystem is 6.14 years,and the net present value is 47.03 million yuan,indicating a significant improvement in system performance.In view of the fact that high-temperature and high-pressure air can be used in the biomass gasification power generation system,this paper presents the integrated coupling of the AA-CAES system and the biomass gasification power generation system.During the charging process,the compression heat of the compressed air is recovered by the low-temperature water from the biomass gasification power generation system.During the discharging process,the compressed air is heated by the heat of the flue gas from the biomass gasification power generation system,and then the compressed air does work in the expander.The compressed air from the expander outlet is heated again by the flue gas and then enters the combustion chamber of the biomass gasification power generation system directly,reducing the power consumption of the compressor in the system and improving the coupling system’s electricity output.The analysis results show that the round-trip efficiency of the AACAES subsystem increases from 63.81%to 84.90%,and the exergy efficiency increases from 63.76%to 80.46%.The dynamic payback period of the AA-CAES subsystem is 4.20 years,with a net present value of 2.21 million yuan.To make a cascade utilization of the compression heat in the AA-CAES system and utilize the compressed air in the system effectively,this paper proposes a coupling system that integrates the AA-CAES system with the waste-to-energy system and the biogas power generation system.During the charging process,the compression heat of the compressed air is recovered in a cascade through the different temperature feed water and condensate from the waste-to-energy system.During the discharging process,the flue gas from the waste-to-energy subsystem is used to heat the compressed air,and the compressed air after doing work in the turbine is used for the biogas power generation,thus increasing the electrical output of the whole coupled system.Additionally,the flue gas from the gas turbine in the biogas power generation system is discharged into the boiler flue of the waste-to-energy system,saving some equipment in the biogas power generation system.The analysis results show that the round-trip efficiency of the AA-CAES system is increased from 63.81%to 75.32%,and the exergy efficiency is increased from 63.76%to 74.31%.Furthermore,the dynamic payback period of the AA-CAES subsystem is 4.47 years,with a net present value of 4.08 million yuan.In view of the important role of the hydrogen energy in the future energy structure,this paper proposes the integration and coupling of the compressed air energy storage system with the electrolytic water hydrogen production system and the hydrogen solid oxide fuel cell combined cycle power generation system.During the charging process,the AA-CAES subsystem and electrolytic water to hydrogen subsystem are used to store electrical energy and store the generated high-pressure air,compressed heat,hydrogen and oxygen separately.During the diacharging process,the low-temperature water in the hydrogen solid oxide fuel cell combined cycle power generation subsystem is used to cool the compressed air and recover the excess heat stored in the cold tank of the AA-CAES system.The compressed air discharged from the AA-CAES subsystem is used to maintain the combustion of the unreacted hydrogen gas in the hydrogen solid oxide fuel cell.By integrating the system,not only can the overall electrical energy output of the system be improved,but the carbon-zero emissions of the system can also be achieved.The analysis results show that the round-trip efficiency of the AA-CAES system has increased from 63.81%to 72.76%,and the exergy efficiency has increased from 63.76%to 70.11%.The dynamic payback period of the AA-CAES subsystem is 3.19 years,and the net present value can reach 61.60 million yuan.In general,this paper researches the complementary integration of the AA-CAES system and the heterogeneous energy system,explores the performance optimization direction of the AA-CAES system,and derives the integration mechanism of the AACAES system based on the complementary heterogeneous energy and the space-time coupling,which provides reliable theoretical support and feasible technological options for the development of compressed air energy storage systems. |
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