METHOD FOR DISTRIBUTING GAS FOR OXY-FUEL COMBUSTION IN CIRCULATING FLUIDIZED BED

摘要

A method for distributing air for oxygen-enriched combustion on a circulating fluidized bed. In the method, the hearth (1) of the circulating fluidized bed carries out three-stage air distribution, the method comprising: blowing in first-stage air (A) from the bottom of the hearth (1), the component of the first-stage air (A) being oxygen and recycled flue gas; blowing in second-stage air (B) from the transition zone between the dense-phase zone and dilute-phase zone of the hearth (1), the component of the second-stage air (B) being the recycled flue gas; and blowing in third-stage air (C) from the side wall of the hearth (1), the component of the third-stage air (C) being oxygen. The present invention realizes stable combustion in high oxygen concentration inside the hearth (1) of a circulating fluidized bed, thus avoiding the problem of localized high temperature caused by the high oxygen concentration, and solving the safety problem of transporting a mixture of oxygen and recycled flue gas having high oxygen concentration.