Thermal stress and strain distributions of a laboratory scale wall fired furnace: A numerical study and experimental verification

Abstract

A numerical framework that couples fluid and solid mechanics is established to obtain the temperature profile in the furnace and the thermal stress and strain fields on the furnace wall, and to predict the critical regions of mechanical reliability. Demonstrated through the model system of a laboratory scale, gas fuel front wall fired furnace, the combustion process is first simulated and the effect of working condition on wall temperature distribution is deduced. The temperature data underpins the stress/strain analysis of the tube wall using finite element analyses. For the front wall fired swirl burner furnace, the back wall (and its edges) exhibits extremely high temperature, thermal expansion, and stress concentration, which may cause thermal fatigue or cracking. If the burners are concentrated in the middle, the structural safety is further threatened. The numerical results are qualitatively consistent with parallel experiment. Simulations also suggest that the combustion rate and diffusion rate in the burner region should be improved in order to prevent the high temperature near the back wall. The present study gives useful insights for combustion adjustment and furnace design.