The model of turbulence

combustion

and heat exchange process in the furnace of coal-fired boiler in one power plant has been separately established

and numerical simulation being carried out.Results of simulation show that the distribution of velocity field and temperature field in the furnace is reasonable

but slagging may occur on water-wall at right and left sides of the furnace outlet

and at the platen's bottom.Through simulation and analysis of variable operating condition

conclusion can be obtained as in the following:by closing the nozzle of primary air and the neighbouring nozzle of secondary air at the mid-level

the wall-brushing gas flow and slagging at the furnace outlet and at the side-wall can be prevented

as well as dispersing thermal load suitably in the burners' region

the flue gas temperature at furnace outlet can be reduced.