Performance analysis of coal-fired power plants integrated with carbon capture system under load-cycling operation conditions

Carbon capture, utilisation and storage is a key technique for achieving carbon neutrality in the power generation sector. Coal-fired power plants integrated with carbon capture systems should be able to operate flexibly to promote high penetration of renewable power. Therefore, in this study, the thermodynamic performance of coal-fired power plants integrated with carbon capture systems (CCS) are evaluated under load-cycling operation conditions, and the effects of system key parameters are studied. Results show that when the solvent flow rate is fixed, the energy consumption rate of CCS increases with the decrease of power load, which causes the efficiency of coal-fired power plants to decrease more significantly with the power load. The energy consumption rate of CCS can be decreased by optimising gas-to-liquid ratio, i.e. by adjusting the inlet mass flow rate of solvent according to the inlet mass flow rate of flue gas. Moreover, the influence of CCS capacity on system efficiency is evaluated. The two parallel CCSs have the lowest energy consumption rate and the highest energy efficiency. As a result, load-cycling performance is enhanced and the improvement is more obvious as the load decreases.