Low NOx Rich-Lean Combustion Concept Application

The rich/quench/lean (RQL) combustion concept has demonstrated a significant reduction in NOx formation in gas turbine applications. The success of this approach relies on the effective and rapid mixing that is required for the transportation of the rich mixture to the lean zone of the combustor. It is realized that better design tools are required to achieve further reduction of NOx to meet the goal for high speed civil transport application. In the present investigation, a 3-D analysis was performed to evaluate its capability to detect the features of the mixing process. The analysis also helped to point to regions of the combustor where NOx could form in larger quantities. A calculation approach was developed, based on chemical reaction concepts, to evaluate the NOx formation and destruction in various combustor zones. The calculated values agreed fairly well with the measurements obtained for the RQL combustor.