REDUCING METHOD FOR N2O OF FLUIDIZED BED BOILER

摘要

PURPOSE:To reduce N2O of a fluidized bed boiler by providing O2 separation equipment on the way of the extension of an air duct and separating O2 from the air sent into a firing furnace and removing N2 from said air to send O2 into the firing furnace. CONSTITUTION:O2 separation equipment 14 separating O2, in air to send the same into a firing furnace 1 and removing N2 from said air is provided on the way of the extension of an air duct 4. A rear heat transfer part 5 is divided into two parts by providing the partition wall 15 expanding in the laterial direction of the rear heat transfer part 5 and extending in an exhaust gas flowing direction and a heat exchange part 8a is provided to the inside rear heat transfer part 5a and an exhaust gas recirculating route 11 is provided to the lower part of said heat transfer part 5a and the gas circulating duct 12 of the exhaust gas recirculating route 11 is connected to the air duct 4 between the O2 separation equipment 14 and the firing furnace 1. A fuel burner 16 for reheating exhaust gas is provided on the upstream side of the heat exchange part 8b of the outside rear heat transfer part 5b and the flue 10 communicating with a chimney 9 is provided to the lower part of the heat exchange part 8b. By this constitution, since the generation of thermal NOx is suppressed and the amount of exhaust gas can be reduced, the fuel consumed by a burner 16 for reheating the exhaust gas is reduced.