CONTOURED SURFACE ANNULAR SECTION OF A GAS TURBINE

Abstract

The invention relates to a blade or vane ring for a gas turbine having a plurality of blades or vanes that are arranged next to one another in the peripheral direction (UR), wherein blades or vanes have a flow segment extending essentially in the radial direction, these blades or vanes having a convex suction side, a concave pressure side, a leading edge and a trailing edge, wherein the suction side and the pressure side are joined together by the leading edge and the trailing edge, wherein the blades or vanes transition into an annular segment of the blade or vane ring radially inside and/or radially outside, wherein annular segment connects a first blade or vane (12) and a second blade or vane, which are adjacent to one another, between the suction side of the first blade or vane and the pressure side of the second blade or vane.

Claims

1. A blade or vane ring (10) for a gas turbine having a plurality of blades or vanes (12) that are arranged next to one another in the peripheral direction (UR), wherein blades or vanes (12) have a flow segment extending substantially in the radial direction, these blades or vanes having a convex suction side (16), a concave pressure side (14), a leading edge (18) and a trailing edge (20), wherein the suction side (16) and the pressure side (14) are joined together by the leading edge (18) and the trailing edge (20), wherein the blades or vanes (12) transition into an annular segment (22) of the blade or vane ring (10) radially inside and/or radially outside, wherein the annular segment (22) connects a first blade or vane (12) and a second blade or vane (12), which are adjacent to one another, between the suction side (16) of the first blade or vane (12) and the pressure side (14) of the second blade or vane (12), wherein the annular segment (22) is a contoured surface area (24) having different heights in the radial direction, wherein the annular segment (22) has a highest surface area section (26) and a deepest surface area section (30), wherein the highest surface area section (26) is formed directly bounding the pressure side (14) of the second blade or vane (12).

2. The blade or vane ring (10) according to claim 1, wherein the highest surface area section (26) lies between the pressure side (14) and an imaginary connection line (VL) that joins the leading edge (18) and the trailing edge (20) of the second blade or vane (12).

3. The blade or vane ring (10) according to claim 1, wherein the deepest surface area section (30) is arranged adjacent to the suction side (16) of the first blade or vane (12), wherein the annular segment (22) has an increasing profile from the deepest surface area section (30) to the suction side (16).

4. The blade or vane ring (10) according to claim 1, wherein the highest surface area section (26), at least in parts thereof and preferably completely, lies in an axial region that extends from a maximum 15% of the axial extent of the blade or vane (12) upstream to a maximum 15% of the axial extent of the blade or vane (12) downstream referred to an imaginary connection line (SL), which joins the center points of a cross-sectional surface area of the blades or vanes (12) in the peripheral direction (UR).

5. The blade or vane ring (10) according to claim 4, wherein the deepest surface area sections (30) lie in front of the connection line (SL) in the axial direction (AR).

6. The blade or vane ring (10) according to claim 1, wherein the contour of annular segment (22) decreases from the highest surface area section (26) from along pressure side (14) of the second blade or vane (12) to the leading edge (18) and to the trailing edge (20) of the second blade or vane (12) and to the suction side (16) of the first blade or vane (12).

7. The blade or vane ring (10) according to claim 1, wherein, referred to a zero line (NL), the highest surface area section (26) has a greater height (+10) than the depth or negative height (5) of the deepest surface area section (30); the absolute value of the height of the highest surface area section (26) is approximately double the absolute value of the depth or negative height of the deepest surface area section.

8. The blade or vane ring (10) according to claim 1, wherein the blade or vane ring (10) is configured and arranged as a rotating blade ring of a turbine stage of a gas turbine.

9. The blade or vane ring (10) according to claim 1, wherein the blade or vane ring (10) is configured and arranged as a guide vane ring of a turbine stage of a gas turbine.

10. The blade or vane ring (10) according to claim 1, wherein the blade or vane ring (10) is configured and arranged as a rotating blade ring or a guide vane ring of a gas turbine.

Description

[0018] The invention will be described below with reference to the attached figures by way of example and not in any limiting manner.

[0019] FIG. 1 shows a simplified schematic perspective illustration of an excerpt of a blade or vane ring with contour lines that represent the contour of an annular segment.

[0020] FIG. 2 shows a simplified qualitative lengthwise profile of an annular segment between two blades or vanes along a line SL of FIG. 1.

[0021] A blade or vane ring 10 shown partially in FIG. 1 comprises a plurality of blades or vanes 12 arranged next to one another in the peripheral direction UR. The blades or vanes 12 have a respective pressure side 14, a suction side 16, as well as a leading edge 18 and a trailing edge 20. Between two adjacent blades or vanes 12 lies an annular segment 22 of blade or vane ring 10, between suction side 16 of a first blade or vane (bottom blade or vane in FIG. 1) and pressure side 14 of a second blade or vane 12 (top blade or vane in FIG. 1). The annular segment 10 is a surface area that joins together two adjacent blades or vanes 12 and extends in the peripheral direction UR and in the ring axial direction AR. The blades or vanes 12 and the annular segments 22 lying between them are preferably formed in one piece with one another; in particular, the blade or vane ring 10 can be manufactured from one casting or from a plurality of castings.

[0022] The surface-area annular segment 22 has a contoured surface 24 facing an annular space through which gas flows and into which the blades or vanes 12 project in the radial direction. Contour lines are plotted in FIG. 1 for illustration, wherein a zero line NL is represented by a dot-dash line. Starting from the zero line NL, the annular segment 22 or its surface 24 rises outwardly in the radial direction, which is illustrated by the dotted contour lines +2 to +10. In this exemplary embodiment, in which an inner shroud is shown, the annular segment 22 or its surface deepens inwardly, starting from the zero line in the radial direction, which is illustrated by the dashed contour lines 1 to 5. The numbers used for the contour lines are merely a qualitative illustration and do not reproduce any real quantitative values. A notation of +2 thus does not mean that it involves 2 units of a specific measurement system such as e.g., millimeters or tenths of millimeters.

[0023] The annular segment 22 has a highest surface area section 26 indicated by the contour line +10. This highest surface area section 26 is applied directly to the pressure side 14 of the blade or vane 12. If one takes an imaginary connection line VL, which joins the leading edge 18 and the trailing edge 20 of the blade or vane 12, the highest surface area section 26 in the peripheral direction UR lies between this connection line VL and the pressure side 14; preferably, the highest surface area section 26 lies completely, thus with its entire surface area (corresponding to approximately the boundary of the contour line +10) within a contour that is formed by pressure side 14 and connection line VL. If one assumes for adjacent blades or vanes 12 a respective center point 28 of a cross-sectional surface area of the blade or vane profile and connects these center points 28 in the peripheral direction UR, this center-point connection line SL will intersect the highest surface area section 26.

[0024] The annular segment 22 or its surface 24 further has a deepest surface area section 30 that is indicated by the contour line 5. This deepest surface area section 30 lies adjacent to suction side 16 of blade or vane 12. Of course, the deepest surface area section 30 is not applied directly to the suction side 16, but is separated from the suction side 16 in the peripheral direction UR. The deepest surface area section 30 preferably also lies in front of the center-point connection line SL in the axial direction AR, whereby the reference in front of refers to the direction of primary flow of gas through the blade or vane ring 10, which is illustrated in FIG. 1 by the double arrow SR.

[0025] Starting from the highest surface area section 26, the annular segment 22 or the surface 24 thereof decreases along the pressure side 14 to the leading edge 18 and to the trailing edge 20. Further, annular segment 22 also decreases in the peripheral direction toward suction side 16 of the adjacent blade or vane 12, in particular down to the level of the deepest surface area section 30, from where the annular segment increases again slightly to suction side 16.

[0026] If one proceeds from the circumstance that the same distance is present between two contour lines in the radial direction both in the plus direction as well as in the minus direction, the highest surface area section 26 has a greater height than the depth or negative height of the deepest surface area section 30; in particular, the height of the highest surface area section 26 is approximately double the depth or negative height of the deepest surface area section 30. In this case, the height or the depth will be compared to one another as absolute values (quantities), without paying attention to the corresponding sign relative to the zero line.

[0027] FIG. 2 shows a simplified lengthwise profile in the peripheral direction UR along the center-point connection line SL of FIG. 1 between pressure side 14 of the second (top in FIG. 1) blade or vane 12 and suction side 16 of the first (bottom in FIG. 1) blade or vane 12. It can be seen from this profile of the surface 24 of annular segment 22 that the highest surface area section 26 connects directly to pressure side 14 of the second blade or vane 12. In this example of embodiment, the highest surface area section 26 forms a type of plateau at the illustrated level +10 referred to the zero line NL.

[0028] Of course, this highest surface area section 26 need not necessarily be formed as planar, but can also have a curvature. In this case, the curvature is so slight, however, that no place in the highest surface area section 26 reaches the level +12 or in fact exceeds it. If the highest surface area section has a singular high point, then it is applied preferably directly at pressure side 14 of blade or vane 12.

[0029] The profile of surface 24 then decreases from the highest surface area section 26 in the direction of suction side 16 of the first blade or vane 12 with partially different slopes, passes the zero level at NL and again decreases down to the level 5. Starting from this level of 5, the profile of surface 24 then slightly increases in the direction of suction side 16 before annular segment 22 transitions into suction side 16 of the first blade or vane 12.

[0030] In the schematic sectional view of FIG. 2, pressure side 14 and suction side 16 of the two blades or vanes 12 are represented as linear. However, this need not be the case. Thus, for structural-mechanical reasons, it may be advantageous, for example, to allow pressure side 14 and/or suction side 16 to transition into annular segment 22 by a so-named fillet, which has a rounding radius similar to a flute groove. Such fillets, however, shall be a component of the blade or vane 12 and not of annular segment 22 according to the present invention.

[0031] Due to the proposed contouring of annular segment 22 between two adjacent blades or vanes 12 of a blade or vane ring, by the arrangement of the highest surface area section 26 directly connecting to pressure side 14, improved aerodynamic flow ratios can be achieved in particular, which lead to an improved efficiency and an improved capacity of the gas turbine.

LIST OF REFERENCE NUMBERS

[0032] 10 Blade or vane ring [0033] 12 Blade or vane [0034] 14 Pressure side [0035] 16 Suction side [0036] 18 Leading edge [0037] 20 Trailing edge [0038] 22 Annular segment [0039] 24 Surface [0040] 26 Highest surface area section [0041] 28 Center point [0042] 30 Deepest surface area section [0043] AR Axial direction [0044] NL Zero level or zero line [0045] UR Peripheral direction [0046] VL Connection line [0047] SL Center-point connection line [0048] SR Primary flow line