NUMERICAL INVESTIGATION OF COMBUSTION AND OXIDATION IN A STEEL REHEAT FURNACE
thesisposted on 12.12.2019, 13:45 by Bethany M Worl
The objective of this research was to develop an efficient simulation of an industrial reheating furnace with a flexible scale formation model and to apply the models to study various conditions within an industrial reheating furnace. This work focused on developing a model capable of considering many different key variables that influence scale formation. The scale formation model was incorporated into the computational fluid dynamics (CFD) software ANSYS Fluent © to solve a coupled steady-state and transient simulation. It was also generalized for a low-carbon steel product, so it may not be adequate to cover the effects of alloying metals on the oxidation process. In order to verify the accuracy of these models, baseline cases were simulated and validated against both industrial data and findings from experiments in published literature.
A parametric study with two levels of oxygen enrichment implementation in only the preheat zone was undertaken to study the effects on the heat transfer, scale formation, and fluid flow within the reheat furnace. A medium oxygen enrichment case of 46 vol% oxygen and an oxy-fuel case were used for study. Both oxygen enrichment cases showed largely increased heat transfer to the slab in the preheat zone and increased scale formation. Based on these results, 46 vol% oxygen enrichment is recommended for use in a typical industrial reheat furnace with additional firing rate drawback to reduce scaling and to reduce the chance of overheating the steel slab product.