OXYGEN COMBUSTION SYSTEM AND METHOD FOR OPERATING SAME

摘要

This system includes: a boiler (1) for burning fuel with combustion gas in which oxygen-rich gas and circulated exhaust gas are mixed; a dust collector (17) provided in a gas duct through which exhaust gas from the boiler flows; a second gas duct (29) for guiding, to the boiler, the combustion gas in which the circulated exhaust gas vented from the gas duct downstream of the dust collector and the oxygen-rich gas; a combustion gas heater (13) for heat exchange between the exhaust gas flowing through the gas duct between the boiler and the dust collector and the combustion gas flowing through the second gas duct; an exhaust gas cooler (15) provided in the gas duct between the combustion gas heater and the dust collector, the exhaust gas cooler exchanging heat between the exhaust gas circulating in the gas duct and a cooling medium to cool the exhaust gas; and a control means for controlling at least one of the flow rate and the temperature of the cooling medium in the exhaust gas cooler so that the temperature of the exhaust gas introduced in the dust collector becomes 90°C-140°C. This can minimize sulfuric acid dew point corrosion of ducts, pipes and devices, and clogging of ducts and pipes with dust.