Computational fluid dynamics (CFD) was used to analyze the effective cooling of a water jacket of an injection nozzle within a coal gasifier. Prior to this analysis, the nozzle melted within 30-min. The CFD was performed and it was observed that a large low-flow eddy was forming at the tip of a nozzle. The low convection coefficient in this vicinity caused a cascading overheating from vapor formation, leading ultimately to the nozzle melting in service. With the CFD, this water jacket was revised to produce an effective consistent flow path, which allowed for the intended cooling to the metal nozzle.
Post this analysis, numerous other nozzles, some with water jacket cooling and others refractory-lined were analyzed using CFD and then mechanically evaluated using finite element analysis (FEA) modeling.
Temperatures from the CFD were mapped to the FEA model, where operating/design/thermal conditions were evaluated using ASME Codes (ASME Section VIII Div. 2 and ASME Section III.5) for static, low cycle fatigue and cyclic-fatigue assessments.
