Guide vane

Abstract

The present invention relates to a guide vane, in particular an outlet guide vane and/or a guide vane for a compressor stage of a gas turbine, wherein the vane has a vane blade with a first vane blade portion and a second vane blade portion, and the first vane blade portion can be reversibly rotated in relation to the second vane blade portion about an axis of rotation from a first position to a second position, wherein, in at least one profile portion of the vane blade, the axis of rotation is arranged outside of a profile of the first vane blade portion, and/or a profile of the first vane blade portion has a suction side with a first contour portion and a second contour portion, which, in particular, is adjoined thereto, and a profile of the second vane blade portion has a pressure-side contour portion.

Claims

1. A guide vane for a compressor stage of a gas turbine, wherein the guide vane has a vane blade with a first vane blade portion and a second vane blade portion and the first vane blade portion is configured and arranged to be rotated reversibly in relation to the second vane blade portion about an axis of rotation from a first position to a second position, wherein, in at least one profile portion of the vane blade, the axis of rotation is arranged outside of a profile of the first vane blade portion and/or a profile of the first vane blade portion has an suction side with a first contour portion and a second contour portion, which is adjoined thereto, and a profile of the second vane blade portion has a pressure-side contour portion, which, in the first position, is overlapped by the first contour portion and, in the second position, is instead overlapped by the second contour portion in the circumferential or peripheral direction; the first contour portion and the second contour portion are circular segments of a same circle wherein a distance from the axis of rotation to the first contour portion and a distance from the axis of rotation to the second contour portion are the same; and wherein the first vane blade portion is separated from the second vane blade portion by a gap and is arranged on at least one platform that is configured and arranged to rotate about the axis of rotation.

2. The guide vane according to claim 1, wherein the second vane blade portion lies, as viewed in a through-flow direction, downstream of the first vane blade portion.

3. The guide vane according to claim 1, wherein the second vane blade portion lies, as viewed in a through-flow direction, upstream of the first vane blade portion.

4. The guide vane according to claim 2, wherein the profile of the second vane blade portion has a suction-side tangent in at least one point in a furthest upstream tenth part of its suction side, and the profile of the first vane blade portion has a tangent in point in the first or second position lying nearest to the at least one point in a furthest upstream tenth part of its suction side, these tangents forming an angle of at least 20° with each other.

5. The guide vane according to claim 1, wherein a distance to the axis of rotation varies along the first contour portion by at most 10%, a distance to the axis of rotation varies along the second contour portion by at most 10%, and/or a distance to the axis of rotation varies along the pressure-side contour portion by at most 10% and the first vane blade portion has a cone-shaped or cylinder-shaped region, which has the first and second contour portions, and/or the second vane blade portion has a cone-like or cylinder-like congruent region, which comprises the pressure-side contour portion.

6. The guide vane according to claim 1, further comprising a seal, which is an elastic seal and/or a contacting seal, for reducing a gap width between opposite-lying regions of the first and second vane blade portions in the first position and/or second position.

7. The guide vane according to claim 1, wherein the axis of rotation is arranged on the side of the pressure side and/or in the at least one profile portion of the vane blade downstream towards or upstream in front of a leading edge and/or upstream in front of a trailing edge and/or outside of the profile of the second vane blade portion.

8. The guide vane according to claim 1, further comprising an outer shroud and/or an inner shroud, at which the first vane blade portion is rotatably arranged via the at least one platform, around the axis of rotation, and/or the second vane blade portion is arranged in a fixed position.

9. The guide vane according to claim 1, wherein the guide vane is an outlet guide vane that is configured and arranged in a compressor stage for a gas turbine.

10. The guide vane according to claim 1, wherein the at least one guide vane is configured and arranged in a compressor stage of a gas turbine.

11. The guide vane according to claim 1, wherein the first vane blade portions of a plurality of the vane blades are adjustable from the first to the second position.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

(1) Additional advantageous further developments of the present invention ensue from the dependent claims and the following description of preferred embodiments. Shown for this purpose, in a partly schematic manner, are:

(2) FIG. 1 shows a guide vane in accordance with an embodiment of the present invention in a first position;

(3) FIG. 2 shows the guide vane in a second position; and

(4) FIG. 3 shows the guide vane in the first position with inscribed tangents.

DESCRIPTION OF THE INVENTION

(5) FIG. 1 shows a profile portion of a vane blade of a guide vane in accordance with an embodiment of the present invention in a first position.

(6) The vane blade has an upstream first vane blade portion 10, which, in the profile section of FIG. 1, has a profile (profile section) 11 with a suction side 12, and, in a through-flow direction (from left to right in FIG. 1), a second vane blade portion 20, which, in the profile section of FIG. 1, has a profile (profile section) 21.

(7) The second vane blade portion 20 is arranged at an outer shroud 30 in a fixed manner.

(8) The first vane blade portion 10 is separated from the second vane blade portion by a gap S, in which a seal 22, which reduces, at least essentially, the gap width to zero, is arranged at the second vane blade portion 20. The first and second vane blade portions can contact each other or, equally, a free gap can be created between them.

(9) The first vane blade portion 10 is arranged at a platform 40 that can rotate around an axis of rotation D and, via this platform 40, is mounted rotatably around the axis of rotation D at the outer shroud 30. At the radially (perpendicular to the plane of the drawing in FIG. 1) opposite-lying ends of the guide vane, which are therefore not visible in FIG. 1, it is possible in an analogous way to arrange the guide vane at an inner shroud, or a design without an inner shroud is also possible.

(10) The axis of rotation D is arranged on the side of the pressure side (bottom in FIG. 1) and, in the profile section of FIG. 1, outside of the profile 11 of the first vane blade portion 10, downstream towards a leading edge 23, upstream in front of a trailing edge 24, and outside of the profile 21 of the second vane blade portion 20.

(11) The suction side 12 of the profile 11 of the first vane blade portion 10 has a first contour portion 12A and, adjoining it upstream, a second contour portion 12B; the profile 21 of the second vane blade portion 20 has a pressure-side contour portion 21A.

(12) In the first position shown in FIG. 1, the first contour portion 12A overlaps the pressure-side contour portion 21A in the circumferential or peripheral direction (vertical in FIG. 1).

(13) When an angle of inflow of the guide vane is adjusted towards the suction side (towards the top in FIG. 1) or becomes more suction-side, the first vane blade portion 10 is adjusted or rotated (twisted) around the axis of rotation D to the second position shown in FIG. 2.

(14) In this second position, instead of the first contour portion 12A, now the second contour portion 12B overlaps the pressure-side contour portion 21A in the circumferential direction (the first contour portion 12A hereby overlaps another (pressure-side) contour portion of the profile (profile section) 21 of the second vane blade portion 20). In other words, the rotation from the first position to the second position brings the second contour portion 12B, in relation to the second vane blade portion 20, to the position of the first contour portion 12A.

(15) When the angle of inflow is adjusted towards the pressure side (towards the bottom in FIG. 1) or becomes more pressure-side, the first vane blade portion 10 is adjusted or rotated (twisted) around the axis of rotation D back to the first position shown in FIG. 1.

(16) Clearly, besides the first and second positions, yet further intermediate positions and/or positions or angular positions going beyond the first or second position are possible.

(17) In the exemplary embodiment, the first and second contour portions 12A, 12B are, at least essentially, circular segments of the same circle and the pressure-side contour portion 21A is, at least essentially, a circular segment of a circle concentric to the former circle, so that the distances r, R to the axis of rotation D along these contour portions are, at least essentially, constant.

(18) FIG. 3 shows the profile section of FIG. 1, with a point P2 being inscribed that lies in a furthest upstream twentieth part of the suction side (top in FIG. 3) of the second vane blade portion 20 or profile (profile section) 21, that is, a suction-side point in the region or in the vicinity of the leading edge 23.

(19) Additionally inscribed is the point P1, nearest-lying to this point P2, of the suction side of the first vane blade portion 10 or profile (profile section) 11.

(20) Moreover, the suction-side tangent T2 in the point P2 (at the suction side of the second vane blade portion 20 or profile (profile section) 21) and the suction-side tangent T1 in the point P1 (at the suction side of the first vane blade portion 10 or profile (profile section) 11) as well as the angle α between these two tangents T1, T2, which is greater than 20°, are drawn in.

(21) As a result of this, the danger of a separation of a leakage (back)flow, which flows between the two vane blade portions 10, 20 through the gap towards the leading edge 23 of the second vane blade portion 20, from the suction side of the second vane blade portion 20 or profile (profile section) 21 is diminished.

(22) Even though exemplary embodiments were explained in the preceding description, it is noted that a large number of modifications are possible. Moreover, it is noted that the exemplary embodiments are merely examples, which are not intended to limit the scope of protection, the applications, and the design in any way. Instead, the preceding description affords the person skilled in the art a guideline for implementing at least one exemplary embodiment, with it being possible to make diverse changes, particularly in regard to the function and arrangement of the described component parts, without departing from the protective scope as it ensues from the claims and the combinations of features equivalent thereto.