System and method for reducing combustion dynamics and NOx in a combustor

摘要

A system for reducing combustion dynamics and NO x in a combustor includes a tube bundle (36) that extends radially across at least a portion of the combustor, wherein the tube bundle (36) comprises an upstream surface (28) axially separated from a downstream surface (30). A shroud (38) circumferentially surrounds the upstream and downstream surfaces (28,30). A plurality of tubes (34) extends through the tube bundle (36) from the upstream surface (28) through the downstream surface (30), wherein the downstream surface (30) is stepped to produce tubes (34) having different lengths through the tube bundle (36). A method for reducing combustion dynamics and NO x in a combustor (10) includes flowing a working fluid through a plurality of tubes (34) radially arranged between an upstream surface (28) and a downstream surface (30) of an end cap that extends radially across at least a portion of the combustor, wherein the downstream surface (30) is stepped.