The invention discloses a method for preventing blockage of a heat storage element of a rotary
air preheater of a
coal-fired power
plant boiler. When the resistance of the
air preheater is increased by 15%-20% than a design value, the rotational speed of the
air preheater is adjusted according to the
unit load and the
exhaust gas temperature of an outlet of the air preheater to increase the temperature of the cold end of the air preheater; the air preheater runs continuously at a
low speed, and when the resistance decreases to the required level, the normal operation of the air preheater is resumed; by reducing the rotational speed of the air preheater, the
exhaust gas temperature is increased; and when the rotational speed of the air preheater is reduced, the heat storage capacity of theheat storage element is increased, the
exhaust gas temperature can be greatly increased, the cold end integrated temperature of the air preheater is increased, and the
flue gas temperature in the middle portion of the heat storage element reaches 250 DEG C, so that
ammonium hydrogen sulfate is sublimated. The method has the advantages that the purposes of removing
ammonium hydrogen sulfate originally attached to the surface of the heat storage element and reducing the resistance of the air preheater are achieved, the
boiler efficiency is improved, the
power consumption rate of a
plant is lowered, and hidden dangers of lowering output or even halt of a
power station are eliminated.