Flow Characteristic of a New Type of Double-Channel Air Burner in Direct Flow Pulverized Coal Boiler

Tangentially-fired burner is widely used in pulverized coal boiler, but its air burner has some shortcomings, including the velocity of exit airflow weaken with the decrease of the opening degree of the air damper, leading to insufficient mixing between air and coal-powder. In view of the existing problems, a new type of double-channel air burner had been designed. Its flow field and adjustment characteristic were studied by using numerical simulation method. The results showed the double-channel air burner had effective flow adjustment characteristic which closely linearity. One of the channels could keep higher exit velocity when the air volume decrease and it could fulfill the demand of air adjustment better while in low NOx combustion or load variation.