| Abstract |
Multi-point ground flares are often the solution of choice to smokelessly flare large quantities of gas. These flare systems are staged so that smokeless operation is possible over a very wide range of gas flows. In most cases, a fence is required around the perimeter of the flare array so that the flare flames are concealed. Because of the requirement to conceal the flames, visible flame height is a key performance metric in the application of multi-point ground flares. Visible flame height is known to vary with burner design, relief gas flow rate, relief gas composition, and relief gas supply pressure. The spacing between adjacent burners is also known to impact flame height. Computational Fluid Dynamics (CFD) modeling is a simulation methodology that can provide a prediction of flow, mixing, and combustion in these flare flames. However, developing a CFD methodology that can accurately predict the visible flame height can be challenging. In this paper we will discuss the impact of mesh fidelity and turbulence-chemistry interaction on CFD predictions of flame height. We will show that certain commonly used modeling methods fail to capture the important combustion physics in multi-point ground flares. We will further illustrate the impact of mesh fidelity or resolution on capturing the flame shape. |
