The Effect of Temperature Distribution on Tube Rupture

This paper reports the effect of temperature distribution on tube rupture at the pulverized coal fired thermal power plant. A computational model was applied to a 150 MWe boiler burning high-ash, medium-volatile coal. The radial and axial flame temperature distribution in the boiler was simulated using CFD code FLUENT. Flame temperatures were measured at points close to wall in some boiler levels and compared with computational fluid dynamics (CFD) solutions. CFD analysis showed that the flame shaped in the centre of the boiler and the temperature decreased gradually towards the boiler walls. The coal and ash composition was analyzed, and tube thickness was measured. Analysis showed that the ash and chlorine content of the coal, and SiO2 content of the ash were very high. Deposits on tubes can occur overheating, fouling and slagging which lead to tube ruptures. The abrasive effect of the ash accelerated thinning of the tubes and caused them to rupture.