Axial swirler

摘要

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.

主权项

1. An axial swirler for premixing of oxidizer and fuel in gas turbines, the axial swirler comprising:
a series of swirl vanes with a streamline cross-section, each swirl vane having a leading edge, a trailing edge, and a suction side and a pressure side extending each between said leading and trailing edges, the swirl vanes being arranged around a swirler axis, wherein said leading edges extend radially outwardly from said axis, wherein flow slots are formed between the suction side of each swirl vane and the pressure side of its circumferentially adjacent swirl vane, wherein at least one swirl vane has a discharge flow angle (α) between a tangent to its camber line at its trailing edge and the swirler axis that is monotonically increasing with increasing radial distance (R) from the swirler axis, and wherein the trailing edge of each of the swirl vanes is rotated with respect to the leading edge; and wherein a discharge flow angle (α) on said radial distance (R) is given by a function:
tan [α(R)]=K·Rβ+H, wherein β is ranging from 1 to 10, and K and H are constants chosen such that the discharge flow angle (α(Rmin)) at a minimum radial distance (Rmin) is from 0 degrees to 20 degrees and the discharge flow angle (α(Rmax)) at a maximum radial distance (Rmax) is from 30 degrees to 50 degrees.