Dynamic modeling and comprehensive analysis of direct air-cooling coal-fired power plant integrated with carbon capture for reliable, economic and flexible operation.

Coal-fired power plants with direct air-cooling condensers (DACC-CFPP) are water-saving, eco-friendly and thus widely installed in regions rich in coal but short of water. As such regions have better geological conditions for CO 2 storage, retrofitting these plants with carbon capture techniques provides a cost-efficient way to reduce carbon emissions and retain dispatchable power. However, the integration of carbon capture poses significant challenges for CFPP and DACC. Therefore, this paper develops a plant-wide model of the 660MWe DACC-CFPP integrated with post-combustion carbon capture (PCC). A connection system, including a steam extraction valve, water spray and condensate returning, is designed, added to the Steam turbine-Feedwater heaters-Condenser system and modeled to reflect dynamic interactions between the DACC-CFPP and PCC. This model is then used to evaluate the reliability, economics and flexibility of the DACC-CFPP-PCC over wide operating conditions. Results show that the integration of PCC causes changes in steam flowrate, pressure and temperature within the turbine, creating reliability risks; brings 5%–10% extra exergy loss to the DACC-CFPP, but not necessarily economic losses; reduces the minimum power load by 44MWe and improve the ramping speed by 3.75MWe/min. This paper provides in-depth insights for decision-makers, designers, and operators to manage the DACC-CFPP-PCC plant. • A plant-wide dynamic model of integrated DACC-CFPP-PCC system is developed. • Reliability, economy and flexibility of the DACC-CFPP-PCC are evaluated. • PCC itself brings 5%–10% additional exergy loss, but not necessarily economic losses. • Power ramping ability of CFPP can be improved if PCC is allowed to operate flexibly. • Turning off fan columns is needed to ensure safe operation in cold weather. [ABSTRACT FROM AUTHOR]