With the quick increase of renewable energy power generation and extensive application of low NOx combustion technologies

the overheating and high temperature corrosion of water wall of coal-fired boilers dramatically aggravated

leading to frequent tube leak accidents. In order to prevent these accidents

it is critical to master the tube wall temperature distribution characteristics of the boiler with different operating parameters. For this reason

a coupled heat transfer model that integrates the three-dimensional CFD model of the gas side of boiler with the one-dimensional hydrodynamic model of the steam side was proposed. The coupled heat transfer calculation between the gas and steam sides of boiler was realized through the data exchange of wall heat flux and steam temperature between the two models. In this way

the crucial effects of gas side heat transfer and steam temperature on the tube temperature were both considered in the calculation

and thereby

realizing the accurate prediction of temperature distribution of water wall tubes. This coupled model was used to simulate the distributions of the steam and wall tube temperature of the spiral water wall of a 350 MW supercritical boiler. The predicted results of the tube temperatures at the outlet of the spiral wall were in good agreement with the measured values verifying the accuracy of the model

indicating the accuracy of the model.