The invention relates to a
system and a blending
combustion method for a
coal-fired
power station boiler for large-proportion blending
combustion of semi-
coke. According to the
system and the blendingcombustion method, the problems that the low-volatile semi-
coke fuel is difficult to fire, poor in
burnout performance and high in
NOx emission during
combustion are solved; optimization of a pulverizing
system, dense-dilute regional combustion of semi-
coke fuel, in-furnace layered blending combustion of the semi-coke and
bituminous coal,
pure oxygen over fire air arrangement and cold energy comprehensive utilization are comprehensively considered; a four-corner tangential combustion mode is adopted, a boiler
hearth five-zone combustion environment is built, and a
power station boiler systemfor large-proportion blending combustion of the semi-coke is developed, so that the proportion of blending combustion of the semi-coke is larger than or equal to 45%; low
NOx emission of an outlet ofa
hearth is realized while high-efficiency combustion of the semi-coke is realized; and low-temperature O2 and low-temperature N2 which are close to 0 DEG C and are obtained by
air separation and obtained through an air-temperature type gasifier are used for realizing deep condensation of desulfurized clean
flue gas, so that water in the clean
flue gas is reduced to the maximum degree,
corrosion of a
chimney is reduced, white
smoke is also eliminated, and
visual pollution around a
power station is reduced.