Such problems as serious salgging

frequent tube burst

superheater and reheater overtemperature and insufficient pulverizing system capacity occurred in the 600 MW unit once-through tower boiler in Yuanbaoshan Power Plant.Thus

the water wall of this boiler was optimized.According to the structural characteristics of the water wall and the heat load distribution features in the furnace after the transformation

the water wall was divided into the flow circuit

pressure point and flow network system comprised of connected tubes.On the basis of the mass conservation equation

momentum balance equation and energy conservation equation

the mathematic models for pressure drop and outlet steam temperature of water wall tube in subcritical boiler were established.Moreover

the total pressure drop in rising system and the outlet steam temperature of the upper and lower water wall were calculated

under conditions with different unit loads.The results show that

the temperature of the inner pipes

outer pipes

middle points and the rear fin are all reliable

which can ensure the boiler work safely.