Patent ID: 6532881
Filing Date: 2003-03-18
Classification: F23C,F23D,F23L,Y02E

Abstract:
A method of operating a steam-generating boiler including a radiation zone and a convection zone comprising:introducing fuel into a combustion space within the boiler; introducing oxygen-enriched air into the combustion space, wherein introducing oxygen-enriched air comprises injecting oxygen-enriched air into one of the radiation zone and the convection zone and wherein recirculating the flue gas comprises introducing the recirculated flue gas into one of the radiation zone and the convection zone; wherein the oxygen-enriched air contains about 21% to about 100% by volume oxygen; combusting the fuel and oxygen-enriched air to generate thermal energy in the combustion space; and collecting at least a portion of flue gases and recirculating at least a portion of the flue gases through the boiler, such that the relationship RC=1-FS&it;Î˜oÎ˜bcis maintained, where RC is a flow rate ratio of oxygen-enriched air to recirculated flue gas, FS is the ratio of fuel consumption between oxygen-enriched air combustion and air combustion, and &THgr;bc represents the flow rate ratio between fuel and air, and fuel, for air combustion and &THgr;o represents the flow rate ratio between fuel and oxygen-enriched air and fuel for oxygen-enriched combustion.