Premix combustor with concentric annular passages.

摘要

A gas turbine combustor (6) having a pre-mixing (10) zone and a combustion zone (12) separated by a barrier plate (57). A plurality of concentrically arranged annular passages, into which lean mixtures of fuel and air are introduced, are disposed in the pre-mixing zone (10). Each of the annular passages (23-26) has a discharge end (35) in which a plurality of swirlers (59) are circumferentially arranged that allow fuel/air mixtures flowing through the annular passages (23-26) to enter the combustion zone (12), the swirlers (59) acting as flame holders. A toroidal fuel manifold (70-73) upstream of each of the annular passages (23-26) allows the fuel/air ratio in each annular passage (23-26) to be individually controlled. The firing temperature of the combustor (6) is increased by sequentially supplying fuel to each annular passage (23-26) in turn, with the innermost passages (23) being supplied with fuel first. A pilot fuel assembly is centrally disposed with respect to the annular passages and has swirler vanes and an ignitor.