NOx model for lean combustion concept

In an effort to reduce the emissions produced by gas turbine combustors to meet the expected trends of more stringent regulations, a model to calculate NOx produced by lean combustion concepts is proposed. The model simulates the combustor by a number of reactors representing the main combustion as well as pilot zones. A detailed reaction rate scheme was used to provide a fundamental basis for the derivation of reaction temperature and NOx formation expressions. The model validation involved the utilization of the data obtained for a combustor that comprised a prechamber in which fuel was vaporized and mixed with air, and a variable geometry feature to control air split between various zones. In addition to the satisfactory agreement with the measurements obtained under a wide range of operations, the model provided insight into the roles of the primary zone and pilot in forming NOx. The present investigation also shows that multidimensional calculations can provide important assistance for emissions model development. Methods of NOx reduction may be implemented in light of such information.