Heat transfer model and cooling performance of converter oxygen lance affected by slag sticking

Abstract

The heat transfer mechanism and water-cooling effect during oxygen lance blowing changes by slag sticking at the nozzle. In order to effectively overcome this problem, in this study, the equivalent heat transfer method was applied to modify the heat transfer coefficient of the oxygen lance nozzle under different slag thicknesses and steel slag thermal conductivities. In addition, the gas–liquid two-phase heat transfer model was established by computational fluid dynamics numerical simulation, and the cooling effects for different types of oxygen lance nozzles were calculated by the improved model. The results show that the error rate between the calculated value of the modified model and the field measured value was reduced to 3.3%–4.6%. The nozzle with double angle and double flow design was found to be conducive to the improvement of the cooling system. In this study, the best cooling effect was obtained when the flow ratio of large nozzles and small nozzles is 60%/40% and the angle is 12°/17°.