Deployment of carbon capture system to coal-fired power plant consumes large amount steam for solvent regeneration andcyclic utilization. Steam consumption reduces the power generation efficiency and output of the plant. The trans-system utilization ofenergy between power system and carbon capture system is vital to decrease the efficiency penalty. By analyzing the flowsheet model offull-scale flue gas carbon capture and the heat balance diagram of steam turbine units,the effect of carbon capture system parameterselection and waste heat utilization on turbine efficiency of a 630 MW plant were studied by equivalent enthalpy theory. 569.18 t/h steamwas consumed in full-scale carbon capture system for solvent regeneration,resulting in the decrease of turbine efficiency from 43.84% to35.74%. Utilization of re-boiler condensate waste heat on heating rich solvent,reducing 0.2 GJ/t regeneration duty and saving 43.05 t/hsteam consumption,exhibits the same outcomes as on regenerative feedwater heating system,while the former choice can be reached witha simpler system. The waste heat from CO2 compressor and regenerated gas,which is related to the rich split ratio of carbon captureprocess,can be recycled by condensate water from turbine to reduce the steam extraction from low pressure turbine to enhance efficiency.The best performance of turbine is reached at mass ratio of 0.2∶0.75∶0.05 (cold rich solvent∶rich solvent mainstream∶rich solventheated by re-boiler condensate). Cutting stages of CO2 compressor increases the recyclable heat at the expense of higher electricityconsumption. After optimization, the power generation of a 630 MW plant with full-scale flue gas carbon capture increases from510.09 MW to 528.96 MW.

王润宇(1991—),陕西西安人,博士。E-Mail:wangrunyu@nwepdi.com

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WANG Runyu, MA Xinqiang. Energy cascaded utilization and turbine efficiency of coal fired power plant with CO2capture[J].Clean Coal Technology,2024,30(10):41−49.