Experimental and numerical analysis of wall heat transfer in non-premixed gas combustor

Prediction of wall heat transfer in combustion chambers attracts attention of design engineers in process industry due its implications for the construction of combustors and boilers. Firstly, this paper addresses the reliability and accuracy of an experiment performed in a large-scale experimental combustion chamber equipped with staged-gas non-premixed 745 kW burner. The experiment serves as means to determine boundary conditions and validate predictions by computational fluid dynamics (CFD) software. Several accuracy issues of the used measuring gauges and instruments are discussed with focus on wall heat fluxes and stabilization of the measured data. Second part of the paper presents CFD simulations of the combustor using Reynolds-averaged Navier-Stokes (RANS) models and validates them by the measured data. Overall model configuration, boundary conditions and key sub-models for turbulence and chemistry are summarised. Deviations of the predictions from the experiment are discussed and possible explanations are offered.