Numerical model incorporating different oxidizer in a reheating furnace fired with natural gas

Abstract

The call for an increase in efficiency and performance leads to constant developments of furnaces and burners. For this purpose, a propagated application of different burner types, often operating with pure oxygen or oxygen enrichment, can be determined. As a consequence numerical models have to be adapted incorporating industrial needs. This work has developed an approach based on the spatial separation of the whole domain into parts, capable of various oxidizer and fuels to be considered. Each of these parts operates with a single oxidizer and fuel each. The advantages are possible improvements on each small part separately, decreasing computational effort needed. Furthermore, different numerical models, for e.g. combustion and turbulence, can be applied. Moreover, the steady flamelet model (SFM), limited to the usage of a single oxidizer and fuel, can be applied. The results, using the SFM have been compared to the eddy dissipation (EDM) and eddy-dissipation concept model (EDC). Clear differences in the highly reactive areas become obvious using the different combustion models. Though the influence on the remaining combustion chamber is low. Consequently, the heating characteristic of the tubes revealed negligible differences. The calculated temperatures inside the combustion chamber and the transient tube temperature have been compared to measurements at the real size furnace disclosing a high consistency. Thus, the presented approach presents a good alternative for researchers and operators to investigate real-size furnaces.