Directing against the existence of big flue gas temperature deviation （up to 130℃） at the furnace exit of 2000t/h boiler in a power plant

cold state test and numerical simulation under four different opposing tangential angles for the air dynamic behaviour in the furnace

the reaidual gas flow swirl at the furnace exit

and the gas flow velocity distribution in the horizontal flue gas duct have been carried out

and the influencing factors upon the flue gas temperature deviation

such as fictitious diameter of the tangential circle

height of the furnace

as well as structure and swing angle of the burner etc.

being analysed. The results show

a reasonable opposing tengential angle can effectively suppress and weaken the gas velocity and gas temperature deviation at the exit of furnace. And it is very helpful to decrease the said deviation by swinging upward the burner for a certain angle.