The causes leading to somewhat low indicating value of the flame detector for very few burners in coalfired utility boiler or misjudgement of the value have been analysed

and resolving measures

such as adjusting the detection distance of the flame detector

eliminating shield of vision for the flame detector

revising the critical value and background evaluation etc.

being put forward. Practice of application on two boilers in Rizhao Power plant shows that the adjustment of detection distance not only can solve the problem of somewhat low indicating value for very few flame detectors

but also can save large amount of fuel oil used for stabilizing combustion

having remarkable economic benefit under condition of stable ignition and combustion for pulverized coal and air flow.