Under thirty operating conditions of one HG 670/13.7-LPM19 type CFB boiler

the measurement has been carried out.By using optimal regression analysis method

some factors affecting the flue gas temperature variation at furnace outlet

such as boiler load

ash in fuel coal on received basis(RB)

volatile matters on RB

net calorific value on RB

particle size of feed coal

bed pressure

primary air flow rate

upper secondary air flow rate

lower secondary air flow rate

oxygen quantity at the furnace outlet etc.

have been analysed.The magnitude of influence resulted from the said parameters' variation

from big to small

is listed as in the following:air distribution mode

bed pressure

oxygen quantity

particle size of feed coal.The change of bed pressure and particle size of feed coal requires longer time

being not used to regulate the flue gas temperature at furnace outlet under general conditions.In order to prevent over-temperature of flue gas at furnace outlet

under prerequisity of keeping other parameters to be stable

the most convenient

rapid

and effective meams is changing the air distribution mode or enhancing the oxygen quantity.The influence of related parameters is different in tendency and magnitude.