To master the hydrodynamic characteristics and wall temperature distribution law of 700 ℃ ultra supercritical unit boiler's hydrodynamic characteristics

this paper takes a 600 MW

35 MPa/700 ℃/720 ℃ ultra supercritical unit with single reheat П type boiler as an example to carry out numerical calculation by universal hydrodynamic calculation method. The results show that

along the wall height direction

the working fluid temperature increases linearly

the wall temperature increases correspondingly

while the heat transfer temperature has little change. The good heat transfer performance of the fluid in the large specific heat region effectively inhibits the peak value of the wall temperature in the high heat load region. Using coiled water wall can control the wall temperature deviation effectively. However

due to the increase of working parameters of the 700 ℃ ultrasupercritical boiler

the outlet wall temperature of the water wall is still as high as 520 ℃

which puts forward higher requirements for boiler water wall materials and the actual operation of boiler.