Development of the dynamic plant simulation in CO{sub}2-recovery type pulverized coal fired power plant applied oxygen/recycled flue gas combustion

摘要

Based on the basic designing of 1,000 MW power plant, the dynamic plant simulation was conducted in order to confirm the realization of the oxygen/recycled flue gas (O{sub}2/RFG) combustion system to recover CO{sub}2 from pulverized-coal fired power plants. First of all, the basic designing of 1,000 MWe pulverizedcoal fired power plant applied O{sub}2/RFG combustion was performed. In the system, the greater part of the flue gas from the boiler was recycled and used as combustion gas after mixing with oxygen and transported gas for pulverized-coal. Five air separation units (ASUs) were installed and they supplied the product oxygen controlled in oxygen flow rate and oxygen concentration to the boiler. During load change, start up and shut down of the plant, therefore it was supposed to be difficult to control the flue gas oxygen concentration, the wind box oxygen concentration, the steam condition and so on in the system. So as to make clear the operationability of the plant, the dynamic simulation was conducted based on the results of the basic designing on engineering work stations (EWS) for plant load change and start up. The program of the dynamic characteristics analysis simulator was developed as a functional expansion of advanced power plant simulation system (APSS) which had been developed by IHI for energy power plants. As the results, it was found that the steam condition at the outlet of the boiler and the draft and the gas concentration at each points could be successfully controlled, though it took a long time to change the combustion mode from air combustion to O{sub}2/RFG combustion. Finally, it was confirmed that pulverized-coal fired power plant applied O{sub}2/RFG combustion was a practical system for CO{sub}2 recovery.