The reheat steam temperature of a 600 MW unit W-flame boiler at 75% load and below is lower than the design value(541 ℃)

which seriously affects the economic efficiency of the unit operation. Through the boiler thermodynamic calculation and the CFD analysis on temperature in the furnace

the reason for low reheat steam temperature is studied. The results show that

at 300 MW

general operation adjustments cannot improve the reheat steam temperature further. The low reheat stem temperature at low load is caused by the relatively unreasonable distribution of high temperature convective heating area. Thus

it proposed to increase the heating area of low temperature heater and high temperature reheater

and reduce the heating area of high temperature superheater. Increasing the heating area of low temperature heater and high temperature reheater can increase the reheat steam temperature and make it reach the design value

but limited by the flue duct arrangement

this method can not be implemented in engineering. While reducing the heating area of the superheater by 2 792 m2 can increase the reheat steam temperature to the design value at 300 MW load

and control the desuperheaing water flow at 0 t/h. In this method

although the reduction of boiler efficiency increases the coal consumption for power generation

the overall reduction of coal consumption is obvious.