A wall-arranged giant ring-shaped direct-current pulverized coal burner includes burner nozzles arranged on four side furnace walls of a boiler. The burner nozzles on the four side furnace walls form a wall-tangential combustion mode in the furnace, and the burner nozzles on each side furnace wall are arranged in a ring by a plurality of small nozzles to form a giant ring-shaped combined nozzle. There is a plurality of small nozzles arranged in a ring on each side furnace wall to form a giant ring-shaped combined nozzle. The giant ring-shaped combined nozzles on the four side furnace walls may form a wall- tangential combustion mode in the furnace. Through the mutual entrainments of the multiple airflows in the giant ring-shaped combined nozzle and the mutual support of the fireside and back-fire-side airflows, the stiffness of each airflow may be effectively enhanced.

A gas turbine engine and combustor assembly including a combustor liner defining therein a combustion chamber for the downstream flow of a main fluid. At least two axially spaced apart annular trapped vortex cavities are located on the combustor liner and staged axially and radially spaced apart. A cavity opening is located at a radially inner end of each of the at least two annular trapped vortex cavities. A plurality of injectors are configured tangentially relative to circular radially outer wall extending between an aft wall and a forward wall of each cavity to provide for an injection of air and fuel to form an annular rotating trapped vortex of a fuel and air mixture within a respective annular trapped vortex cavity. The annular rotating trapped vortex of the fuel and air mixture at the cavity openings is substantially perpendicular to the downstream flow of the main fluid.

A gas turbine engine and combustor assembly including a combustor liner defining therein a combustion chamber for the downstream flow of a main fluid. At least two axially spaced apart annular trapped vortex cavities are located on the combustor liner and staged axially and radially spaced apart. A cavity opening is located at a radially inner end of each of the at least two annular trapped vortex cavities. A plurality of injectors are configured tangentially relative to circular radially outer wall extending between an aft wall and a forward wall of each cavity to provide for an injection of air and fuel to form an annular rotating trapped vortex of a fuel and air mixture within a respective annular trapped vortex cavity. The annular rotating trapped vortex of the fuel and air mixture at the cavity openings is substantially perpendicular to the downstream flow of the main fluid.

A burner outlet set for a downshot firing burner is described comprising a first outlet array having at least one primary outlet, and at least one vent air outlet disposed either side of the primary outlet in an array direction of the first outlet array; second and third outlet arrays each comprising an array of secondary air outlets, respectively disposed either side of the a first outlet array. A burner system with a plurality of such burner outlet sets, a burner arch configured for downshot firing and having one or more such burner sets, and a combustion furnace with one or more such arches are also described.

A combustor assembly including a combustor liner defining therein a combustion chamber for the downstream flow of a main fluid. At least two annular trapped vortex cavities are located on the combustor liner and staged axially spaced apart. A cavity opening is located at a radially inner end of each of the at least two annular trapped vortex cavities spaced apart from a radially outer wall and extending between an aft wall and a forward wall of each cavity. A plurality of injectors are configured tangentially relative to the circular radially outer wall to provide for an injection of air and fuel to form an annular rotating trapped vortex of a fuel and air mixture within a respective annular trapped vortex cavity. The annular rotating trapped vortex of the fuel and air mixture at the cavity openings is substantially perpendicular to the downstream flow of the main fluid. A gas turbine engine including the combustor assembly is disclosed.