Taking a 1000MW ultra-supercritical tower type boiler as research object, two-dimensional discrete model is established to predict the heat transfer and wall tube temperature in the furnace, while the convective heat transfer is considered. By comparison to the measured data, the predictive data have a fine accordance, and the maximal deviation is 5.26% approximately, which verify the reliability of this model. Based on the model, the proportion of convective heat flux in the furnace and the effect on wall temperature are investigated. The calculated value of wall temperature increase by 16.7℃ at most under consideration of convective heat transfer, which can improve the accuracy of predictive calculation. Further, under the given load conditions, the distribution of water wall temperature in the primary combustion zone were obtained. The maximal calculated wall temperature is close to 524℃, that is lower than the allowable temperature of material, with a safety margin of 4.8%.
