DUAL FUEL ULTRA-LOW NOX COMBUSTOR

摘要

An ultra-low NOx gas turbine combustor having a dual fuel capability. The combustor has a pre-mixing zone and a downstream combustion zone. The pre-mixing zone has three concentric annular passages that surround a central diffusiontype dual fuel nozzle. A gas fuel manifold distributes gas fuel around the inner and outer passages. A plurality of dual fuel nozzles are disposed in the middle passage to distribute either gas or oil fuel around the middle passage. The distribution of fuel around the passages allows the formation of lean fuel/air ratios, thereby lowering NOx formation. In addition, swirl vanes are arrayed around the inner and outer passages and around each of the fuel nozzles. A step increase in the flow area in going from the pre-mixing zone to the combustion zone creates vortices that tend to anchor the flame.