Abstract:
The present invention relates to an axial swirler, in particular for premixing of oxidizer and fuel in gas turbines. The axial swirler for a gas turbine burner includes a plurality of swirl vanes with a streamline cross-section being arranged around a swirler axis and extending in radial direction between an inner radius Rmin and an outer radius Rmax. Each swirl vane has a leading edge, a trailing edge, and a suction side and a pressure side extending each between the leading and trailing edges. A discharge flow angle a between a tangent to the swirl vane camber line at its trailing edge and the swirler axis is first function of radial distance R from the swirler axis. A position of maximum camber of the swirl vane is second function of radial distance R from the swirler axis. At least one swirl vane of the first and second functions include each a respective local maximum and local minimum values along said radial distance from Rmin to Rmax. The invention also relates to a burner with such a swirler.
Abstract:
A method for premixing air with a gaseous fuel for being burned in a combustion chamber includes: guiding the air in an air stream along a burner axis through a coaxial air tube into a combustion chamber arranged at an end of said air tube; and impressing a swirl on the air stream by passing it through a first swirl device concentrically arranged within the air tube and comprising a plurality of radially oriented first blades. The method further includes: injecting gaseous fuel into the air stream at the first swirl device; and mixing said air in said air stream with the injected gaseous fuel in a first mixing zone arranged just after said first swirl device
Abstract:
An axial swirler, in particular for premixing of oxidizer and fuel in gas turbines, includes a series of swirl vanes with a streamline cross-section. Each swirl vane has a leading edge, a trailing edge, and a suction side and a pressure side extending each between the leading and trailing edges. The swirl vanes are arranged around a swirler axis, wherein the leading edges extend essentially in radial direction. Flow slots are formed between the suction side of each swirl vane and the pressure side of its nearest neighboring swirl vane. Furthermore, at least one swirl vane has a discharge flow angle between a tangent to its camber line at its trailing edge and the swirler axis that is monotonically increasing with increasing radial distance from the swirler axis. The invention also relates to a burner with such a swirler and a method of operating the burner.
Abstract:
An axial swirler for a gas turbine burner includes a vane ring with a plurality of swirler vanes circumferentially distributed around a swirler axis. Each of the swirler vanes includes a trailing edge. In order to achieve a controlled distribution of the exit flow velocity profile and/or the fuel equivalence ratio in the radial direction. The trailing edge is discontinuous with the trailing edge having a discontinuity at a predetermined radius.