Whole-course operation system and method for SCR denitration device of coal-fired power plant boiler

The invention discloses a whole-course operation system and method for an SCR denitration device of a coal-fired power plant boiler, and belongs to the field of environmental protection equipment. According to the whole-course operation system, a denitration inlet flue expansion joint, multiple flue gas heater systems arranged in parallel, a heat insulation protective plate, a flow guide baffle and an ammonia spraying pipeline are sequentially arranged on a denitration inlet flue in the flue gas flow direction. After the coal-fired power plant boiler is ignited to start up, when a DCS system shows that the flue gas temperature of a denitration inlet and the flue gas temperature before the ammonia spraying pipeline are lower than lower limit of catalyst allowed ammonia spraying temperature, the DCS system automatically controls the flue gas heater systems to start up according to a set program. When the flue gas temperature before the ammonia spraying pipeline is higher than the lower limit of catalyst allowed ammonia spraying temperature by 10 DEG C or more, the DCS system automatically turns off the corresponding flue gas heater systems. Finally, the flue gas temperature before the ammonia spraying pipeline is kept above the lower limit of catalyst allowed ammonia spraying temperature.