Ultra low emissions gas turbine combustor

摘要

The gaseous fuel-fired can combustor for a gas turbine include a generally cylindrical housing, and a generally cylindrical liner disposed coaxially within the housing to define with the housing a radial outer flow passage for combustion air, the-liner also defining inner combustion and a dilution zone, the dilution zone being axially distant a closed housing end relative to the combustion zone. A fuel/air mixing apparatus disposed at the closed housing end includes a plurality of swirl vanes defining passages each having constant cross-section flow areas along the vanes, and an increasing aspect ratio from the passage inlet to the outlet. An impingement cooling sleeve coaxially disposed in the combustion air passage between the housing and the liner cools the portion of the liner defining the combustion zone. Channeling apparatus is disposed between a downstream end region of the sleeve and the mixing apparatus and includes a diffuser section with a ratio of the outlet flow area to the inlet flow area in a range of 1.3-1.5.

主权项

1. A gaseous fuel-fired can combustor for a gas turbine engine, the can combustor comprising:
a generally cylindrical housing having a housing interior, a housing axis, and a closed housing end; a generally cylindrical combustor liner disposed coaxially within the housing interior and configured to define with the generally cylindrical housing a radial outer flow combustion air passage, the generally cylindrical combustor liner also defining respective radially inner volumes for a combustion zone and a dilution zone, the dilution zone being axially distant to the closed housing end relative to the combustion zone, and the combustion zone being axially adjacent the closed housing end; a mixing apparatus disposed at the closed housing end and in flow communications with the combustion air passage, the mixing apparatus including a plurality of vanes for mixing gaseous fuel to be combusted with at least a part of combustion air and a mixing apparatus outlet for admitting a resulting fuel/air mixture to the combustion zone; an impingement cooling sleeve coaxially disposed in the combustion air passage between the generally cylindrical housing and the generally cylindrical combustor liner, the impingement cooling sleeve having a first plurality of apertures sized and distributed to direct combustion air against a radially outer surface of a combustion liner portion of the generally cylindrical combustor liner defining the combustion zone for impingement cooling the combustion liner portion; and a channeling apparatus disposed in the combustion air passage for channeling combustion air from an impingement cooling sleeve exit region to an inlet of the mixing apparatus, wherein the channeling apparatus is configured to prevent flow separation and includes a diffuser section with a diffuser section inlet flow area and a diffuser section outlet flow area, and wherein a ratio of the diffuser section outlet flow area to the diffuser section inlet flow area is between 1.3-1.5, wherein a flanged connection is provided between the impingement cooling sleeve and the generally cylindrical housing proximate the diffuser section inlet flow area, and wherein a second plurality of apertures are provided for injecting air into the diffuser section immediately downstream in the combustion air passage of the flanged connection to prevent flow separation in the diffuser section using combustion air from the combustion air passage that has not passed through the impingement cooling sleeve.