Abstract: For the past few years, along with domestic energy source demands increasing, the supplydemand equivalence of coal for power generation was broken, and the coal supply of power generation enterprises became diversified. The coal quality became lower, the coal rank became complex, the control difficulty of asfired coal quality was increased, and the equipment defects caused by the poor coal quality obviously increased. Combining with the practical conditions of #3 and #4 units in Pingdingshan Yaomeng Power Generation Corporation Limited, the influences of firing poorgrade coal on safety and economical effici

Key words: poor-grade coal, fire extinguishing, safety, economical efficiency