It had been stipulated in operation code that the corresponding burners have unconditionally to inject ignition oil for supporting combustion in the course of ordinarily starting up or shutting down coal pulverizers.Through researching the ignition process of pulverized coal and air flow in the course of starting up or shutting down coal pulverizers for a direct and wall firing boiler

the heat absorbing process before ignition of pulverized coal and air flow for corresponding burners of starting up or shutting down coal pulverizer and for burners maintaining in operation has been analysed and compared

and a mode without injecting fuel oil or injecting little fuel oil during the time of starting up or shutting down coal pulverizers being put forward.This mode can be adopted for direct and wall firing boilers at time of unit's load being higher than a cetain load point.