| 摘要 |
A low emissions combustor system for a gas turbine includes a combustion chamber liner defining a combustion space for combusting a homogeneous fuel and compressed air mixture received through an inlet to produce combustion gases for delivery to the turbine through a liner exit. The liner has both principal dilution ports and secondary dilution ports adjacent and upstream of the liner exit, and a premixer assembly operatively connected to the liner for providing the fuel/air mixture. The premixer assembly includes an air valve for controlling the fuel/air ratio of the mixture. The combustor system also includes a compressed air supply plenum upstream of, and in flow communication with, the air valve. A shroud partly surrounds the liner and provides a cooling channel between the plenum and the principal dilution ports. The combustor system still further includes a bypass channel between the plenum and the secondary dilution ports, and a bypass valve operatively positioned to control flow from the plenum through the bypass channel. Alternatively, a single valve may be employed for regulating the flow of compressed air into the compressed air supply chamber and the bypass channel in lieu of an air valve and bypass valve, which combines their functions. Also, the liner can include an annular ridge extending into the combustion space for increasing residence time of the fuel/air mixture and combustion gases in the combustion space.
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