Through testing

the main causes leading to desuperheating water quantity to go beyond the limit for 2000t/h boilers have been analysed and determined. It is considered that the main causes are as follows: （1） The boiler manufacturer has insufficient understanding of the Shenfu coal and it’s ash and slag properties; （2） the selected furnace cleanliness factor was larger; （3） the designed heating surface of furnace evaparator was smaller. All of these results in comparatively high flue gas temperature at the outlet of furnace. Through measures of combustion adjustment

adopting air distribution in steps

and burning under low oxygen etc.

it is achieved to make the desuperheating water quantity of said boilers to be lowered

Providing with basis for technical retrofit of oil-fired boilers in the future.