Taking an ultra-supercritical double-reheat tower type boiler as the research object

zonal method was adopted to establish the two-dimensional discrete model for the space in furnace and the surface of the water wall. The model couples the combustion and radiative heat transfer in furnace with the hydrodynamics inside the water wall tube

then reasonably simplifies the process to adapt the engineering application. The overall heat transfer characteristics and wall tube temperature distribution of spiral water wall were simulated under typical working conditions. The results show that

a bimodal distribution of heat flux exists along the height of the furnace wall

while the peak value of heat flux approaches 400 k W/m2. At the identical height

the values of heat flux and tube temperature on middle surface of the furnace exceed that on the corner of the furnace

and the non-uniformity in main combustion zone is obviously higher than that in over fire air zone. Under the BMCR condition

the maximum heat flux is almost up to 479.5 k W/m2

while the highest tube temperature is about 530.5 ℃.