A New 1D/3D Model of Conjugate Heat Transfer in Waterwall Tubes of Power Boiler Combustion Chamber

The paper presents the mathematical model for simulating heat transfer processes in waterwalls of supercritical steam boilers combustion chambers. The model is based on the distributed parameters. The proposed model enabling on-line simulation of transient heat and flow phenomena. The one dimensional model (1D) is solved for the fluid domain. A three-dimensional (3D) model is proposed for waterwall tubes with fins. In each analyzed cross-section of a waterwall tube with fins, there were specified 20 control volumes for which the energy balance equations were formulated in a 3D space. To verify the results obtained there were carried out computations for waterwalls of the combustion chamber of supercritical boiler operating in one of the Polish power plants. The proposed 1D-3D model allows obtaining fully satisfying results and may be applied to working in the on-line mode.