Practice of Deep Desulphurization in a 300MW CFB Boiler

Design of the first “300MW Circulating Fluidized Bed (CFB) boiler+limestone/gypsum wet Flue Gas Desulphurization (FGD) system” in the world is introduced, operating parameters of the boiler and FGD system are analyzed. The operating bed temperature is higher than 940°C, efficiency of the boiler is more than 93.5%. In the mean time, SO₂ remove efficiency is higher than 95%, and 65% dust remove efficiency is gotten in the FGD system. Practice showed that deep desulphurization and deNO_x of CFB boiler has higher SO₂ remove efficiency at lower Ca/S ratio compared with traditional inner desulphurization mode, it can meet more and more rigid environmental protection emission standard, and is suitable to more fuels. Deep desulphurization and deNO_x of CFB boiler can also realize high temperature CFB boiler which doesn’t aim to inner desulphurization and low NO_x emission, and benefits to low-grade, high sulfur content fuels. Research of deep desulphurization and deNO_x should be a developing direction for large capacity CFB boiler.