Abstract: A combustor includes inner and outer arrays of generally Vee-shaped, radially extending, circumferentially spaced gutters canted in a circumferential direction relative to one another to produce isolated concentric counter-rotating circumferentially directed flows downstream of the gutters. A lean premixed combustion mode is used at baseload operations. At non-baseload operations, particularly low-load operating conditions, a diffusion combustion mode is employed by direct fuel injection into air supplied to one of the isolated flow fields, preferably the radially inner flow field, to produce a stabilized, locally hotter flame, resulting in higher combustion efficiency and lower emissions than otherwise using a lean premixed combustion mode at the non-baseload operating conditions.

Abstract: A centerbody cup construction for use in a dry low NOx gas turbine combustor includes a pair of inner and outer generally cylindrical members, the inner member having a diverging cup portion attached to its forward end extending toward the outer cylindrical member, and a coolant manifold arranged between the inner and outer cylindrical members radially adjacent the centerbody cup portion.