REGENERATIVELY COOLED TRANSITION DUCT WITH TRANSVERSELY BUFFERED IMPINGEMENT NOZZLES

摘要

A cooling arrangement (56) having: a duct (30) configured to receive hot gases (16) from a combustor; and a flow sleeve (50) surrounding the duct and defining a cooling plenum (52) there between, wherein the flow sleeve is configured to form impingement cooling jets (70) emanating from dimples (82) in the flow sleeve effective to predominately cool the duct in an impingement cooling zone (60), and wherein the flow sleeve defines a convection cooling zone (64) effective to cool the duct solely via a cross-flow (76), the cross-flow comprising cooling fluid (72) exhausting from the impingement cooling zone. In the impingement cooling zone an undimpled portion (84) of the flow sleeve tapers away from the duct as the undimpled portion nears the convection cooling zone. The flow sleeve is configured to effect a greater velocity of the cross-flow in the convection cooling zone than in the impingement cooling zone.

主权项

1. A cooling arrangement, comprising:
a duct configured to receive hot gases from a combustor can; and a flow sleeve surrounding the duct and defining a cooling plenum there between, wherein the flow sleeve is configured to form impingement cooling jets emanating from dimples in the flow sleeve effective to cool the duct in a first zone having impingement cooling, and wherein the flow sleeve is configured to form a convection cooling zone effective to cool the duct solely via a cross-flow, the cross-flow comprising spent impingement cooling fluid from the impingement cooling jets, and the cross-flow flowing from the first zone having impingement cooling into the convection cooling zone, wherein in the first zone having impingement cooling, an undimpled portion of the flow sleeve tapers away from the duct as the undimpled portion nears the convection cooling zone, wherein a cross-sectional flow area of the cooling plenum decreases in the convection cooling zone and the decreased cross-sectional flow area is effective to accelerate the cross-flow to a greater velocity in the convection cooling zone than a velocity of a cross-flow in the first zone having impingement cooling, and wherein the convection cooling zone is disposed downstream of an outlet of the combustor can with respect to a direction of flow of the hot gases.