Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
  • F01D5/12—Blades
  • F01D5/14—Form or construction
  • F01D5/141—Shape, i.e. outer, aerodynamic form
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D9/00—Stators
  • F01D9/02—Nozzles; Nozzle boxes; Stator blades; Guide conduits, e.g. individual nozzles
  • F01D9/04—Nozzles; Nozzle boxes; Stator blades; Guide conduits, e.g. individual nozzles forming ring or sector
  • F01D9/041—Nozzles; Nozzle boxes; Stator blades; Guide conduits, e.g. individual nozzles forming ring or sector using blades
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2220/00—Application
  • F05D2220/70—Application in combination with
  • F05D2220/72—Application in combination with a steam turbine
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2240/00—Components
  • F05D2240/20—Rotors
  • F05D2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
  • F05D2240/301—Cross-sectional characteristics
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2250/00—Geometry
  • F05D2250/20—Three-dimensional
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2250/00—Geometry
  • F05D2250/70—Shape
  • F05D2250/71—Shape curved

Definitions

• the present invention relates to a guide vane for a turbomachine, in particular for a steam turbine with at least one row of guide vanes.
• curved blades are used as an embodiment of turbine blades, in particular when strong three-dimensional flows occur, which show pronounced radial differences in the static pressure curve between the rotor side and the stator side, and which arise due to the deflection in the guide vanes.
• the flow of a flow medium in a last stage of a low-pressure turbine with a large inflow cross-section leads, in particular with a large ratio between blade length and hub, to a radial reaction distribution having a negative effect on the efficiency of the steam turbine.
• the reaction distribution here is different in the radial direction, being low at the hub and high at a housing of the turbine, which is generally considered disadvantageous.
• a high response in the hub area reduces the gap losses in the vane ring and thus leads to improved efficiency.
• curved guide vanes are used.
• Turbines with curved in the axial direction and in the circumferential direction vanes are known for example from DE 42 28 879 A1.
• the blades Upstream of a playpen a fixed guide grid is arranged, the blades are optimized in terms of number and in terms of their ratio chord to pitch fluidically for full load. They give the flow required for the entry into the playpen swirl.
• the curvature of the blades is perpendicular to the chord, which is achieved by a displacement of the profile cross sections both in the circumferential direction and in the axial direction. The curvature of the vanes is against the
• a turbine blade is known, which is negatively swept in the flow direction at its rotor-side end and at its stator end and inclined in a radial direction with respect to the flow direction at its rotor-side end and at its stator end against the pressure side , This is thus a turbine with both in the circumferential direction and in the axial direction curved turbine blades.
• EP 0 916 812 B1 discloses an output stage of an axially flow-through turbine with a large channel divergence and with a series of curved guide vanes and a row of tapered and twisted blades, wherein the guide vanes are positively swept in the axial direction at their rotor-side end and their stator end negative are, in each case with respect to the course of the rotor-side channel boundary.
• the positive sweep of the vane extends over two-thirds of the blade height and then passes into the negative sweep, wherein in the positive sweep the vane trailing edge is parallel to the vane leading edge and in the negative sweep between the guide and blade against the wall continuously spreading axial diffuser forms with increasing delay of the axial component of the fluid.
• the invention is based on the general idea, in a turbomachine, of at least the guide vanes of a vane row having a lean curve, a sweep curve, a torsion, a chord length that varies over the radial extent of the guide vane, and a cross-sectional profile that varies over the radial extension of the guide vane Mistake.
• the guide vane row has a hub-side circumferential step, which falls back in the flow direction radially to the axis of rotation of the turbomachine inward. This can combine several advantages. On the one hand, a radial distribution of a through the
• Turbine flowing mass flow and a radial pressure gradient is reduced, while on the other hand, a larger mass flow, that is mass flow, is excited in the region of the hub.
• the impact energy of water droplets is reduced, whereby the erosion behavior is favorably influenced.
• the reduced impact energy can be used to reduce the degree of reaction at the blade tip, whereby lower absolute speeds can be realized at a Leitschaufelabströmkante, so that lower leakage losses will occur.
• FIG. 1 shows a cross section through a turbomachine according to the invention in the region of a guide blade
• FIG. 3 is a plan view in the radial direction of a vane
• Fig. 5 is a highly schematic representation for explaining a
• Fig. 6 is a representation as in Fig. 5, but for explanation of a
• a sectional guide blade 4 is shown by way of example in a flow space 1, which is arranged between a rotor hub 2 and a radial outer wall 3, the housing.
• a vane 4 is not to be construed restrictively, so that the invention also includes other blades arranged in turbomachines, such as e.g. Blades that should be included.
• the vane 4 has a so-called lean curve, which is directed in the circumferential direction and wherein a bending angle ⁇ varies along the radial blade length, ie from the hub 2 to the radial outer wall 3.
• the lean curve of the vane 4 decreases along the radial
• the lean curvature of the vane 4 is a positive lean curvature, i. the curvature extends in the direction of rotation 5 of the guide blade 4.
• the shape of the curved guide blade 4 preferably represents a generally continuous arc, which forms an acute angle ⁇ with the hub 2 or the outer wall 3.
• the angle of curvature ⁇ lies between a tangent 7 resting against a trailing edge 12 or leading edge 16 of the vane 4 on a blade surface 6 and a jet 9 orthogonal to the axis of rotation 8 of the turbomachine and preferably in a range of 0 ° ⁇ ⁇ 15 °.
• a so-called sweep curvature of the vanes 4 is shown, including a curvature in the axial direction, ie parallel to the chord 10 of the Guide vanes 4 is understood.
• the sweep curvature is described here by a curvature angle ⁇ , which varies along the radial blade length and has a positive value at the hub 2 and a negative value at the housing 3.
• a positive value is defined according to FIG. 2 in that the chord 10 extends above an intersection point 11 with the jet 9 extending orthogonally to the axis of rotation 8 of the turbomachine to the right of the jet 9, while at a negative angle of curvature ⁇ above the intersection point 11 to the left of Beam 9 runs.
• the angle of curvature ⁇ is thus located between a meridional tangent 7 resting against a leading edge 16 or at an outflow edge 12 on the blade surface 6 and the jet 9 extending orthogonally to the axis of rotation 8 of the turbomachine and usually has a value of 15 ° ⁇ ⁇ -20 ° on.
• the guide vane 4 also has a torsion in the radial direction
• the torsion or the rotation is defined by a metal angle CC 2 , which on the one hand between a circumferentially of the turbomachine the respective trailing edges 12 of the respective vanes 4 connecting circumferential line 21 and on the other hand, the tangent of the curvature centerline 13 at the leading edge 16 and the trailing edge 12 respectively is.
• the metal angle CC2 Similar to the sweep curve or the lean curve, the metal angle CC2 also varies along the radial blade length, wherein it is greater in the region of the hub 2 than on the housing 3.
• a region of the metal angle CC2 that is favorable for the aerodynamic conditions of the turbomachine is usually located here at 25 ° ⁇ 2 ⁇ 10 °.
• FIG. 4 shows a longitudinal section in the region of the guide blade 4 through the turbomachine, with a hub-side circumferential step 14 too is recognizable, which falls back in the flow direction 15 radially to the axis of rotation 8 of the turbomachine inward.
• the circumferential step 14 has an S-shaped profile between the leading edge 16 and the trailing edge 12. However, this is not mandatory, it may alternatively have a linear course between the leading edge 16 and the trailing edge 12. Due to the peripheral stage 14, a hub diameter at the leading edge 16 is greater than at the trailing edge 12, which also positively affects the aerodynamic properties.
• a height of the peripheral stage 14 is determined by the angle ßi and ß2, which are each determined between a tangent 7 on the peripheral level 14 on the one hand and the axis of rotation 8 of the turbomachine or a parallel thereto on the other hand and usually in a range of - 20 ° ⁇ ßi, 2 ⁇ 20 ° lie.
• the tangent 7 to the peripheral stage 14 at an intersection 17, in which the said tangent 7, a center of gravity line 18 and the peripheral step 14 intersect their largest slope.
• the inflection point is usually also located.
• chord length s and the blade spacing t are recorded as linear variables and can be determined by the radial extent of the
• Guide vane 4 vary, wherein usually the pitch ratio t / s at the blade root 2 is smaller than at the blade tip 3.
• Fig. 6 are two other features of the guide vanes 4 according to the invention, namely shown on the one hand over the radial blade length of the guide vane 4 varying angle of incidence cci and a wedge angle WE, which between a surface tangent 7a a pressure side 19 and a surface tangent 7b a suction side 20 varies at the trailing edge 12 of the vane 4 over the radial blade length.
• the inflow-side incident angle cci of the curvature center line 13 on the blade root 2 is smaller than the blade tip 3 and is, for example, in a range of 55 ° ⁇ cci ⁇ 110 °.
• the angle of incidence cci thus increases from the blade root 2 to the blade tip 3.
• the wedge angle WE at the blade root 2 is greater than at the blade tip 3 and preferably decreases continuously from the blade root 2 in the direction of the blade tip 3.
• the wedge angle WE is usually in a range of 15 ° ⁇ WE ⁇ 0 °.
• the guide vanes 4 are formed such that at least the curvature angle ⁇ of the lean curve and / or the curvature angle ⁇ of the sweep curve do not change along the radial blade length, provided they are with respect to the curvature centerline 13 or with respect to the leading edge 16 be measured.
• a narrowest flow cross-section q is defined between two adjacent guide vanes 4, which shifts between hub 2 and housing 3 counter to the flow direction 15.
• An angle ⁇ is bounded on the one hand by the tangent T and on the other hand by the tangent 7 "on the tangent T.
• the tangent T lies on the suction side 20 of the trailing edge 12, while the tangent 7" bears against the suction side 20 of the guide vane 4 and simultaneously orthogonal to the flow bottleneck q is aligned.
• the angle ⁇ decreases from the hub 2 to the housing 3 and is variable along the radial blade length.
• a typical range for the angle ⁇ is between - 5 ° ⁇ ⁇ 15 °.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Turbine Rotor Nozzle Sealing (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

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ID=38055104

Family Applications (1)

Country Status (5)

Cited By (4)

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Citations (8)

Family Cites Families (24)

• 2007
  • 2007-03-23 WO PCT/EP2007/052828 patent/WO2007113149A1/de not_active Ceased
  • 2007-03-23 DE DE112007000717T patent/DE112007000717A5/de not_active Ceased
  • 2007-03-23 JP JP2009502049A patent/JP2009531593A/ja active Pending
  • 2007-03-23 CN CN200780020163.4A patent/CN101460706B/zh not_active Expired - Fee Related
• 2008
  • 2008-09-30 US US12/241,825 patent/US20090257866A1/en not_active Abandoned
• 2010
  • 2010-12-23 US US12/929,047 patent/US20110164970A1/en not_active Abandoned
• 2012
  • 2012-01-23 JP JP2012000297U patent/JP3174736U/ja not_active Expired - Lifetime

Patent Citations (8)

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