EP3438416B1 - Stator blade segment for a turbo engine - Google Patents

Description

The present invention relates to a guide vane segment for a turbomachine, in particular for a gas turbine, in particular for a turbine stage of a gas turbine, a guide vane, in particular a turbine stage, with the guide vane segment and a turbo machine, in particular a gas turbine, with the guide vane segment and a method for producing the guide vane segment .

In principle, guide vane segments for turbomachines are known from the prior art, in particular for gas turbines, which have one or more profiles for fastening the guide vane segment in a turbomachine housing. Due to the high temperatures occurring during operation of the turbomachine, uneven thermal expansion of the guide vane segment during operation can lead to undesirable stresses and / or leaks in the area of the fastening of the guide vane segments to the turbomachine housing.

From the GB 2 471 185 It is known that the contact surface of an upstream hook profile designed to rest on the turbine housing and the contact surface of a downstream hook profile of a guide vane segment for a gas turbine designed for contact with the turbine housing for an operating state below a defined operating temperature with mutually different curvatures in the circumferential direction, based on an axis of rotation of the gas turbine , and designed with a different curvature to the contact surface of the turbine housing in order to achieve a complete contact of the contact surfaces of the hook profiles of the guide vane segment in the circumferential direction on the turbine housing at the defined operating temperature.

One object of an embodiment of the present invention is to improve a guide vane segment, in particular its fastening in a turbomachine housing.

This object is achieved by a guide vane segment with the features of claim 1, by a guide grille with the features of claim 13, by a turbo machine with the features of claim 14 and by a method with the features of claim 15. Advantageous embodiments of the invention are the subject of the subclaims.

According to one embodiment of the present invention, a guide vane segment for a turbomachine, in particular for a gas turbine, in particular for a turbine stage of a gas turbine, has one or more guide vanes and one or more shrouds, in particular at least one outer shroud, with at least one profile arranged on the shroud, which In the present case also referred to as the first profile, for fastening the guide vane segment on the turbomachine housing side, the (first) profile extending in the circumferential direction at least partially over a circumferential length of the guide vane segment along the shroud of the guide vane segment and at least one extending at least partially in the axial direction and in the circumferential direction Functional surface, in particular for fastening the guide vane segment on the turbomachine housing side, at least the functional surface of at least this (first) profile in one or more radial planes perpendicular to a he axis of rotation of the turbomachine in the circumferential direction at the temperatures of at least one temperature range below a defined operating temperature of the turbomachine each has at least two mutually different curvatures.

Thus, according to one embodiment of the present invention, the functional surface of at least one profile for fastening the guide vane segment on the turbomachine housing side is curved in the circumferential direction of the guide vane segment, based on a functional installation state in a turbomachine housing, at the temperatures of at least one temperature range below a defined operating temperature with at least two mutually different curvatures and in the circumferential direction there are in particular at least one functional surface of the profile in at least one radial plane to the axis of rotation of the turbo machine at least two different circles of curvature, the two circles of curvature differing in particular in their radius of curvature and / or in their center of curvature.

By introducing at least two different curvatures into a functional surface of a profile for fastening the guide vane segment on the turbomachine housing side, with a corresponding configuration of the two different curvatures of the functional surface, a change in curvature occurring as a result of heating of the guide vane segment can be at least partially compensated for, so that in one embodiment at least the defined operating temperature on the turbomachine housing side, an at least substantially complete contact of the functional surface on an associated, turbomachine housing-side contact surface can be achieved, in particular on a contact surface on the turbomachine housing side that is curved with a constant curvature.

As a result, an improved, turbomachine housing-side support of the guide vane segment in the turbomachine housing can be achieved in one embodiment. Additionally or alternatively, a sealing effect on the turbo machine housing side can be improved in one embodiment, which has an advantageous effect on the efficiency of the turbo machine.

In the present case, the indication of direction "axial" refers to a direction parallel to a rotation or (main) machine axis of the turbo machine, the indication of direction "circumferential direction" corresponds to a direction of rotation about this rotation or (main) machine axis, the indication of direction "radial" means a direction perpendicular to the axial direction and the circumferential direction.

In the present case, the term “radial plane” refers in a manner customary in the art to a normal plane (s) to an axis of rotation, in the present case in particular to a normal plane (s) to the axis of rotation of the turbomachine, ie in particular to a plane oriented perpendicular to the (main) machine axis.

In the present case, a circle of curvature, in particular a circle of curvature belonging to a point of a curve, is understood in the customary manner as a circle which, with a point of a curve y = f (x), the tangent at this point, ie the first derivative y '= f' (x), and the second derivative y "= f" (x) has in common.

In one embodiment of the present invention, the at least one profile of the guide vane segment extends in the circumferential direction, in particular completely over the circumferential length of the shroud of the guide vane segment.

In one embodiment of the present invention, the functional surface of the profile extends in the circumferential direction, in particular completely over the entire circumferential length of the profile.

In one embodiment of the present invention, the at least one profile arranged on the shroud is designed for fastening the guide vane segment on the turbomachine housing side, in particular for supporting and / or sealing on the turbomachine housing side. In particular, at least one functional surface, in particular at least partially, is designed as a support surface, via which forces acting on the guide vane segment, in particular during operation of the turbomachine, can be supported on the turbine housing side, and / or at least partially designed as a sealing surface for sealing on the turbomachine housing side, in particular corresponding to a contact surface on the turbomachine housing side.

In one embodiment of the present invention, the at least one functional surface of the at least one profile runs in at least a partial axial direction, ie at least with one directional component in a direction parallel to the axis of rotation of the turbo machine, in one embodiment without curvature, ie it extends in this direction in particular linearly , or points across its width in at least partial axial direction has a constant curvature or also has at least two different curvatures, ie or follows a curve profile with a changing radius of curvature in at least partial axial direction.

The term “constant” means “constant” in the customary manner within the meaning of the invention, but includes deviations of up to ± 10%, in particular deviations within the usual tolerance ranges.

In one embodiment of the present invention, a guide vane segment in particular additionally has an inner shroud for fastening the guide vane segment on the rotation axis side, in particular for fastening on a turbo machine housing on the rotation axis side.

In one embodiment of the present invention, the guide vane segment has at least one or the first, in particular upstream, in particular most upstream, profile and a second, in particular downstream, in particular most downstream, profile, the functional surface of the first Profile and the functional surface of the second profile in particular each have at least two different curvatures in at least one radial plane to the axis of rotation of the turbomachine in the circumferential direction at the temperatures of at least one temperature range below a defined operating temperature.

In this way, a particularly stable fastening of the guide vane segment on the turbomachine side can be achieved.

In one embodiment of the present invention, the two profiles are arranged at axially opposite end regions and / or ends of a shroud, in particular a common shroud, in particular the outer shroud, and extend in particular in the circumferential direction at least partially over a circumferential length of the guide vane segment, in particular along of the associated shroud of the guide vane segment, and in particular each have at least one functional surface extending at least in the axial direction and at least partially, preferably completely, over the circumferential length of the guide vane segment, in the circumferential direction.

In this way, an improved fastening of the guide vane segment on the turbomachine side can be achieved.

In one embodiment of the present invention, at least one profile arranged on the shroud is designed at least partially over its length in the circumferential direction as a hook profile, preferably completely over the entire circumferential length of the guide vane segment.

In this way, a particularly stable, turbomachine-side fastening of the guide vane segment can be achieved in a simple manner.

In one embodiment of the present invention, the first profile and / or the second profile has at least one projection extending at least partially in the axial direction and in the circumferential direction with (each) an inner surface oriented inward in the radial direction and one in the radial direction outwardly oriented outer surface, with the first, upstream profile in particular the inner surface of the projection and in the second, downstream profile in particular the outer surface of the projection (each) at least partially forming the functional surface.

In this way, improved support can be achieved, in particular also in the case of a tilting moment about an axis perpendicular to the axis of rotation that occurs as a result of the flow forces, in particular a complete contact of the functional surfaces on the turbo machine housing side. In particular, this can prevent at least one functional surface from lifting off from an associated, turbomachine-side contact surface due to the tilting moment. Rather, the tilting moment can in particular increase a contact pressure of the guide vane segment an associated contact surface on the turbomachine side, in particular in the region of at least one functional surface of the guide vane segment.

In one embodiment of the present invention, the first profile and / or the second profile, in particular in each case, have a profile cross-section with a first projection lying inward in the radial direction and extending at least partially in the axial direction and in the circumferential direction and with a second projection in further out in the radial direction and also at least partially in the axial direction and in the circumferential direction and with a web connecting the two projections, at least partially in the radial direction in between, in particular (each) an at least partially U-shaped profile cross-section, where, in particular (in each case) in the first profile, the inner surface of the second, radially further outward projection at least partially forms the functional surface and / or in the second profile in particular (in each case) the outer surface of the second, further outward projection.

In this way, a particularly simple fastening of the guide vane segment on the turbomachine housing side can be achieved.

In one embodiment of the present invention, at least one functional surface of at least one profile has a first functional surface section and at least one further functional surface section, in particular at least two further functional surface sections, the first functional surface section in at least one radial plane perpendicular to the axis of rotation of the turbomachine in the circumferential direction in at least one temperature range below the defined operating temperature of the turbo machine is curved with a first, in particular constant, curvature and at least one further functional surface section, in particular at least two further functional surface sections, in at least one radial plane to the axis of rotation of the turbo machine in the circumferential direction in at least one temperature range below the defined operating temperature of the turbo machine with another, is curved different from the first curvature and in particular constant curvature.

This can simplify the manufacture of a guide vane segment according to the present invention. In particular, the two different curvatures of a functional surface in the circumferential direction can be introduced in a simple manner and one after the other.

In particular, the curvature of the functional surface, in particular in the first functional surface section, is defined in the circumferential direction by a first circle of curvature and / or a first cylinder of curvature extending in the axial direction, i.e. parallel to the axis of rotation of the turbo machine, and in particular in the second functional surface section by a further circle of curvature or cylinder of curvature.

Thus, in one embodiment of the present invention, at least one functional surface of at least one profile runs in the first functional surface section in the circumferential direction, in particular along a circular path segment defined by a first circle of curvature or by a first cylinder of curvature, and in the second functional surface section in the circumferential direction, in particular along one defined by a second circle of curvature or a second cylinder of curvature Circular segment.

In one embodiment of the present invention, the first functional surface section in the circumferential direction in particular directly adjoins at least one of the further functional surface sections, the first functional surface section merging in at least one radial plane to the axis of rotation of the turbo machine in the circumferential direction, in particular tangentially, into the further functional surface section adjoining the first functional surface section.

As a result, discontinuities in the course of the functional surface, in particular in the circumferential direction, which, among other things, have a disadvantageous effect on the strength of the guide vane segment due to the stress peaks that occur, and beyond that, can result are disadvantageous with regard to the sealing on the turbo engine housing side, can be avoided.

In one embodiment of the present invention, in particular at least one functional surface section of at least one functional surface of at least one profile has a constant curvature in the circumferential direction at least over part of its circumferential length, in particular over its entire circumferential length.

In one embodiment of the present invention, at least one functional surface of at least one profile has three functional surface sections, in particular a first functional surface section, a first further functional surface section and a second further functional surface section, the first functional surface section being arranged in the circumferential direction in particular between the two further functional surface sections.

If the functional surface of at least one profile has only a first functional surface section and only one further functional surface section, i.e. only two functional surface sections, at least one of the functional surface sections extends in particular over half of the functional surface in the circumferential direction, with both functional surface sections in particular each over half of the functional surface in the circumferential direction extend.

In one embodiment of the present invention, in particular in the case of a functional surface with two or three functional surface sections in the circumferential direction, at least one of the functional surface sections extends over a proportion of the circumferential length of the associated functional surface of at least 20%, at least 30%, at least 40% or at least 50% up to a maximum of 50%, 60%, 70% or 80%.

In one embodiment of the present invention, in particular in the case of a functional surface with three functional surface sections in the circumferential direction, in particular at least one of the functional surface sections extends over a portion of the Circumferential length of the associated functional surface of approximately 33%, in particular 33% of the circumferential length of the functional surface.

In one embodiment of the invention, the curvature of the functional surface of the first functional surface section is defined over at least part of the circumferential length, in particular over the entire circumferential length of the first functional surface section, in the circumferential direction by a first circle of curvature with a first radius of curvature, which lies in a radial plane to the axis of rotation of the turbo machine the center of the first circle of curvature lies in particular on the axis of rotation of the turbomachine.

Thus, in one embodiment of the present invention, the center of curvature of the first circle of curvature defining the curvature of the first functional surface section coincides in particular with the axis of rotation of the turbomachine, i.e. with the (main) machine axis. In particular, the curvature of the functional surface in the first functional surface section is constant over the circumferential length of the first functional surface section, i.e. defined by the same circle of curvature, the course of the functional surface of the first functional surface section being defined in particular by a segment of the first circle of curvature in the associated radial plane.

In one embodiment of the present invention, the curvature of the functional surface of at least one further functional surface section is defined over at least part of the circumferential length, in particular over the entire circumferential length of the further functional surface section, in the circumferential direction by a further circle of curvature with a further radius of curvature lying in a radial plane to the axis of rotation of the turbo machine , wherein the center of the further circle of curvature is in particular offset from the axis of rotation of the turbo machine.

In one embodiment of the present invention, the center of the further circle of curvature lies in a common radial plane, in particular with the center of the first circle of curvature, which defines the curvature of the first functional surface section.

The radius of the second circle of curvature can be different from the radius of the first circle of curvature, or if the center of the second circle of curvature does not coincide with the center of the first circle of curvature, it can be equal to the radius of the first circle of curvature.

In one embodiment of the present invention, the second circle of curvature, which defines the curvature of the second functional surface section, in particular over the entire circumferential length of the second functional surface section, is the same, in particular the course of the functional surface in the second functional surface section through a circle segment of the second circle of curvature in the radial plane in the associated Radial plane is defined.

In an alternative embodiment of the present invention, the center point of the first circle of curvature is arranged offset to the axis of rotation, in particular the center point of at least one further circle of curvature coinciding with the axis of rotation.

In a further, alternative embodiment of the present invention, all center points of the first circle of curvature and the further circles of curvature which define the curvature of at least one functional surface are offset from the axis of rotation, and in particular at least two center points of the circle of curvature are offset from one another and / or at least two circles of curvature point two from one another different radii of curvature.

In one embodiment of the present invention, at least one further radius of curvature of at least one further circle of curvature is smaller than the first radius of curvature of the first circle of curvature, in particular by at least 2%, 3%, or 5% and a maximum of 5%, 7.5% or 10%. That is to say, in particular, the radius of at least one further circle of curvature is at most 98%, 97% or 95% and at least 95%, 92.5% or 90% of the radius of the first circle of curvature.

In this way, assuming a corresponding selection of the associated radii of curvature and the position of the centers of curvature, it can be achieved in a relatively simple manner that the associated functional surface is deformed as a result of heating of the guide vane segment during operation of the turbomachine in such a way that at least at the defined operating temperature a sets constant curvature of the functional surface in the circumferential direction, in particular over the entire circumferential length of the functional surface.

In particular, an "expansion", i.e. a reduction in the curvature of the functional surface in the circumferential direction, in particular of the outer functional surface sections, can be compensated for, in particular in a targeted manner.

In one embodiment of the present invention, the functional surface is curved symmetrically in the circumferential direction in at least one radial plane to the axis of rotation of the turbomachine, based on the circumferential length of the functional surface of the guide vane segment, in particular symmetrically with a deviation of up to ± 10% with regard to the position of the axis of symmetry to a center of the functional surface in the circumferential direction and / or with regard to the course of the functional surface with a deviation of up to ± 10% from the associated radius of curvature.

In one embodiment of the present invention, the at least two mutually different curvatures of at least one functional surface of at least one profile of the guide vane segment are selected in such a way that the functional surfaces have a constant curvature in the circumferential direction when the guide vane segment is properly installed in a turbomachine when the turbomachine is in operation, at least at the defined operating temperature has, which in particular by a circle of curvature lying in a radial plane to the axis of rotation of the turbomachine is defined with a radius of curvature, the center of which lies on the axis of rotation of the turbomachine.

In this way, at least at the defined operating temperature, complete contact of the functional surface of the guide vane segment in the circumferential direction on the turbomachine housing side can be ensured.

In one embodiment of the present invention, a guide vane for one, in particular one, turbo machine, in particular for one, in particular one, gas turbine, in particular for one, in particular one, turbine stage of a gas turbine, has one or more guide vane segments according to one of the embodiments described here.

In one embodiment of the present invention, a turbomachine, in particular a gas turbine, in particular at least one turbine stage of the gas turbine, has at least one guide vane segment according to one of the embodiments described here.

To produce a guide vane segment according to one of the embodiments described here, in one embodiment the guide vane segment is first produced by primary molding, in particular by casting or a generative process, and then machined, with at least one functional surface of at least one profile, in particular at least by machining with a geometrically undefined cutting edge is machined, in particular by grinding, to introduce the at least two mutually different curvatures of the functional surface in the circumferential direction. In particular, in a first step, the first curvature is introduced into the functional surface over its entire length in the circumferential direction and, in particular, in at least one further step, the associated further curvature in at least one further functional surface section. Correspondingly, in one embodiment, at least one of the functional surfaces is machined with a geometrically undefined cutting edge, in particular by grinding, in particular its mutually different curvatures are produced.

When the first curvature is introduced into at least one functional surface, in one embodiment the center point of a rotationally symmetrical machining tool, in particular the center point of a rotationally symmetrical grinding tool, coincides with the center point of the first circle of curvature and in particular defines a first grinding center point.

When a further curvature is introduced into the functional surface, in one embodiment the center of a rotationally symmetrical machining tool, in particular the center of a rotationally symmetrical grinding tool, coincides with the center of the associated, further circle of curvature and defines a further grinding center point, the further grinding center point being offset in particular to the center of the first grinding center point lies.

In this way, the two different curvatures can be introduced into the functional surface in a simple manner.

In one embodiment of the present invention, the guide vane segment is made from a nickel-based alloy, in particular a nickel-based superalloy or a cobalt-based superalloy, or has a nickel-based alloy, nickel-based superalloy or cobalt-base -Super alloy on.

Fig. 1

einen Ausschnitt eines Leitschaufelsegments nach einer ersten Ausführung der vorliegenden Erfindung in perspektivischer Darstellung bei einer Betriebstemperatur unterhalb einer definierten Betriebstemperatur;

Fig. 2a

einen Ausschnitt eines Leitschaufelsegment nach einer weiteren Ausführung der vorliegenden Erfindung, ebenfalls in perspektivischer Darstellung bei einer Betriebstemperatur unterhalb einer definierten Betriebstemperatur;

Fig. 2b

den Ausschnitt des Leitschaufelsegments aus Fig. 2a;

Fig. 3

einen Ausschnitt des Leitschaufelsegments aus Fig. 2a und 2b in einem turbomaschinengehäuseseitig befestigten Zustand in einer schematischen Schnittdarstellung;

Fig. 4

das äußere Deckband des Leitschaufelsegments aus Fig. 2a und 2b und 3 in einer ersten perspektivischen Darstellung;

Fig. 5

das äußere Deckband des Leitschaufelsegments aus den Fig. 2a bis 4 in einer zweiten perspektivischen Darstellung;

Fig. 6

das äußere Deckband aus den Fig. 2a bis 5 in einer dritten perspektivischen Darstellung; und

Fig. 7

den Ausschnitt des Leitschaufelsegments aus Fig. 2a und 2b bei der definierten Betriebstemperatur.

Further advantageous developments of the present invention emerge from the subclaims and the following description of preferred embodiments as well as the associated figures. Parts and / or sections with the same function are provided with the same reference symbols. This shows, partly schematically:

Fig. 1

a section of a guide vane segment according to a first embodiment of the present invention in a perspective view at an operating temperature below a defined operating temperature;

Fig. 2a

a section of a guide vane segment according to a further embodiment of the present invention, also in a perspective view at an operating temperature below a defined operating temperature;

Figure 2b

the section of the guide vane segment Fig. 2a ;

Fig. 3

a section of the guide vane segment Fig. 2a and 2 B in a state fastened on the turbomachine housing side in a schematic sectional view;

Fig. 4

the outer shroud of the guide vane segment Fig. 2a and 2 B and 3 in a first perspective view;

Fig. 5

the outer shroud of the guide vane segment from the Figures 2a to 4 in a second perspective illustration;

Fig. 6

the outer shroud from the Figures 2a to 5 in a third perspective illustration; and

Fig. 7

the section of the guide vane segment Fig. 2a and 2 B at the defined operating temperature.

Fig. 1 shows a section of a guide vane segment according to a first embodiment of the present invention in a perspective illustration at an operating temperature below a defined operating temperature.

This guide vane segment 10 has six guide vanes 11, which are each connected to one another by an outer shroud 12 that is further outward in the radial direction, based on an axis of rotation A of an associated turbomachine, and by an inner shroud 12 that is further radially inward and not shown here.

Arranged on the outer shroud 12 are two profiles 16, 17 each extending in the circumferential direction U over the entire circumferential length L of the guide vane segment 10 for fastening the guide vane segment 10 on the turbine housing side, the guide vane segment 10 having a first upstream profile 16 and a second, downstream profile 17 , with respect to a flow direction S, in which the guide vane segment 10 is flown through during the operation of an associated turbo machine.

The two profiles 16 and 17 are each designed as continuous hook profiles 16, 17 with an essentially U-shaped cross section.

Both hook profiles 16 and 17 each have two projections 16I and 16A or 17I and 17A, one further inward in the radial direction 16I or 17I and one further outward in the radial direction 16A and 17A, the projections 16I and 16A or 17I and 17A of the two hook profiles 16, 17 each extend essentially in the axial direction, ie essentially parallel to the axis of rotation A.

An outer surface 18 of the outer projection 17A of the second, downstream profile 17, which is oriented outward in the radial direction, and an inner surface 19 of the outer projection 16A of the first, upstream profile 16, which is oriented inward in the radial direction, are each designed as a functional surface 18 and 19, respectively. The functional surfaces 18 and 19 each extend in a radial plane perpendicular to the axis of rotation A of the turbomachine in the circumferential direction U, ie along the outer projections 17A and 16A in the circumferential direction U, and in the axial direction, in particular parallel to the axis of rotation A.

In the state shown, ie at an operating temperature below the defined operating temperature, the functional surface 18 points in a radial plane perpendicular to the axis of rotation A, in particular over its entire width in the axial direction two mutually different curvatures, the functional surface 18 being defined in at least two points by two mutually different circles of curvature, symbolized by the two mutually different radii of curvature R1 and R2.

In this embodiment of a guide vane segment 10 according to the present invention, the two circles of curvature that define the curvature of the functional surface 18 differ both in the position of their centers M1 and M2 and in their radius R1 and R2, the center M1 of the first circle of curvature with the radius R1 coincides with the axis of rotation A.

The Fig. 2a and 2 B each show a section of a guide vane segment 20 according to a second embodiment of the present invention, for the sake of clarity in FIGS Fig. 2a and 2 B only a part of the reference numerals is shown in each case. The guide vane segment 20 differs from that in FIG Fig. 1 guide vane segment 10 shown according to a first embodiment of the present invention that both the functional surface 18 and the functional surface 19 have three adjoining and tangentially merging functional surface sections, wherein in Fig. 2a the functional surface sections 18A, 18B and 18C of the functional surface 18 are shown recognizable and in FIG Figure 2b the functional surface sections 19A, 19B and 19C of the functional surface 19, which each have different curvatures from one another.

The two outer, in relation to the illustration left and right, functional surface sections 18B or 19B and 18C or 19C each extend over a portion of 33% of the circumferential length L of the associated profile 17, while the middle, first functional surface section 18A and 19A extends over a portion of the circumferential length L of the associated profile 17 or 16 of 40% in the circumferential direction U.

In this embodiment of a guide vane segment 20 according to the present invention, the curvature of the individual functional surface sections 18A, 18B and 18C or 19A, 19B and 19C in the circumferential direction U is constant.

Thus, in the guide vane segment 20, the functional surfaces 18 and 19 in the first functional surface section 18A and 19A run along a circular path segment of a first circle of curvature, which is defined by a circle center M1 and a first radius of curvature R1 or R4, while the functional surfaces in the second functional surface section 18B and 19B extend in the circumferential direction U along a circular path segment of a second circle of curvature which is defined by a second center of the circle of curvature M2 and a second radius of curvature R2 or R5. In the third functional surface section 18C and 19C, the functional surfaces 18 and 19 run in the circumferential direction U along a circular path segment which is defined by a third circle of curvature with a third center of the circle of curvature M3 and a third radius of curvature R3 and R6.

The center of the circle of curvature M1 of the first circle of curvature is selected in such a way that it coincides with the axis of rotation A of the turbomachine, while the two centers of the circle of curvature M2 and M3 of the two further circles of curvature are offset from the axis of rotation A and in this case, in particular, are also offset from one another.

However, in this embodiment of the present invention, the centers of curvature M1, M2 and M3 of the circles of curvature defining the curvature of the functional surface all lie in a common radial plane to the axis of rotation A.

The centers of the circle of curvature of a profile 16 or 17 can lie with the centers of the circle of curvature of the other profile 17 or 16 in a common radial plane or in a radial plane different therefrom.

The two radii of curvature R2 or R5 and R3 or R6 of the two outer functional surface sections 18B and 18C or 19B and 19C are each selected to be smaller in this embodiment than the radius of curvature R1 or R4 of the first circle of curvature, which is the curvature of the central functional surface section 18A or .19A defined.

As a result, assuming a corresponding selection of the associated radii of curvature R1, R2 and R3 or R4, R5 and R6 and the position of the centers of curvature M1, M2 and M3 in relation thereto, the associated functional surface can be achieved in a relatively simple manner 18 or 19 are deformed as a result of the guide vane segment 20 heating up during operation of the turbomachine in such a way that at least at the defined operating temperature, a constant curvature of the functional surface 18 or 19 is established in the circumferential direction U, in particular over the entire circumferential length L of the functional surface 18 or 19 In particular, an "expansion", ie a reduction in the curvature of the functional surface 18 or 19 in the circumferential direction, in particular of the outer functional surface sections 18B and 18C or 19B and 19C, can be compensated for, in particular in a targeted manner.

The functional surfaces 18, 19 have no curvature in the axial direction. That is, the functional surfaces 18, 19 extend in the axial direction along a straight line.

The individual, respectively adjacent functional surface sections 18A, 18B and 18C or 19A, 19B and 19C each directly adjoin one another and each merge tangentially into one another.

Fig. 3 shows a section of the guide vane segment from Fig. 2a and 2 B in a state fastened on the turbomachine housing side in a schematic sectional view, with the aid of this illustration particularly clearly showing how the guide vane segment 20 is supported on the turbomachine housing side via the two profiles 17 and 16 on the turbomachine housing 30, in each case via the outer projections 16A and 17A of the two profiles 16 and 17.

In order to avoid that during operation, in particular as a result of a tilting moment occurring when fluid flows through the guide vane segment 20 in the flow direction S, about an axis perpendicular to the axis of rotation A, in this case an axis oriented perpendicular to the plane of the drawing, the guide vane segment 20, in particular its Functional surfaces 18 and 19, raised from the associated contact surface or contact surface on the turbomachine housing side, the guide vane segment 20 is supported on the turbomachine housing 30 via the radially outwardly oriented functional surface 18 of the second, downstream hook and the radially inwardly oriented functional surface 19.

With such a configuration, tilting moments occurring as a result of a flow lead to increased support instead of lifting of the functional surfaces 18, 19 from the associated contact surfaces of the housing 30.

In this way, on the one hand, it can be prevented that the forces are distributed over a smaller support surface, especially in the case of high forces occurring as a result of the additional tilting moment. This is advantageous for reasons of strength. Furthermore, leaks caused by lifting the functional surface (s) 18, 19 from the associated contact or abutment surface can be avoided. This is particularly advantageous with regard to the efficiency of the turbomachine.

Fig. 4 shows the shroud 22 of the guide vane segment 20 from Fig. 3 in a first perspective illustration, in which it is particularly easy to see in this perspective illustration how the functional surface 18 of the second, downstream profile 17 extends both in the circumferential direction U along the profile 17 and in the axial direction, in particular linearly without a curvature.

The same applies to the functional surface 19 of the front, upstream profile 16, the functional surface 19 also extending in the axial direction as well as in the circumferential direction U over the length of the profile 16 and also not having any curvature in the axial direction.

Based on Fig. 5 the individual functional surface sections 18A, 18B and 18C of the functional surface 18 of the second, downstream profile 17 and their extension in the circumferential direction U over the entire circumferential length L of the profile 17 and their extension also in the axial direction can be clearly seen.

As with Fig. 6 As can be seen, the radially inwardly oriented functional surface 19, which is formed by the inner surface of the outer projection 16A of the front, upstream profile 16, also has three functional surface sections 19A, 19B and 19C, which are also arranged directly adjacent to one another and also merge tangentially into one another and are each defined by an associated circle of curvature and each have a constant curvature in the circumferential direction U.

The first functional surface section 19A of the functional surface 19 is defined by a first circle of curvature with a first radius of curvature R4, the center of curvature of the associated circle of curvature in particular also coinciding with the axis of rotation A.

The second functional surface section 19B also has a constant curvature in the circumferential direction U over the length of the functional section 19B, the curvature of the second functional surface section 19B being defined by a second circle of curvature with a second radius of curvature R5, the center of which is offset from the axis of rotation A, but in particular in a common radial plane with the center of the first circle of curvature.

The third functional surface section 19C also has a constant curvature in the circumferential direction U over the length of the functional surface section 19C, the curvature of the third functional surface section 19C being defined by a third circle of curvature with a third center of the circle of curvature and a third radius of curvature R6, the third center of the circle of curvature also being offset is arranged to the axis of rotation A, but in particular also lies in a common radial plane with the first center of the circle of curvature and the second center of curvature.

The radius R5 of the second circle of curvature and the radius R6 of the third circle of curvature are in particular, as in the case of the functional surface 18, each smaller than the radius R4 of the first circle of curvature. The radius of the second circle of curvature R5 and the radius of the third circle of curvature R6 are also different from each other.

Fig. 7 FIG. 10 shows the guide vane segment 20 from FIG Fig. 2a and 2 B at the defined operating temperature, only the individual functional surface sections 19A, 19B and 19C of the functional surface 19 being designated for the sake of clarity. This in Fig. 7 The guide vane segment 20 shown has deformed, in particular "widened", as a result of the heating during operation of the turbomachine, compared to that in FIG Fig. 2a and 2 B shown condition below the defined operating temperature. In particular, the curvature of the functional surfaces 18 and 19 has decreased, in particular in the two outer functional surface sections 19B and 19C or 18B and 18C.

In the state shown at the defined operating temperature, the two functional surfaces 18 and 19 of the guide vane segment 20 each have a constant curvature in the circumferential direction U over the entire circumferential length L of the profiles 16 and 17, instead of two different curvatures as below the defined operating temperature according to the Fig. 2a and 2 B what in Fig. 7 is symbolized in each case by arrows labeled "R", which represent the respective radii R of the associated circles of curvature at the operating temperature.

In a particularly advantageous embodiment of the present invention, in particular with a suitable choice of the individual radii of curvature R1, R2 and R3 or R4, R5 and R6 as well as a suitable choice of the position of the center points M1, M2 and M3 of the associated circles of curvature, at least depending on the operating conditions, Due to the geometrical design of the guide vane segment 20 and the material of the guide vane segment 20, the functional surfaces 18 and 19 are curved concentrically around the axis of rotation A at least at the defined operating temperature, as in the present case.

Due to the generally greater wall thicknesses of the turbomachine housing, the bearing or contact surfaces on the turbomachine housing side generally deform significantly less during operation, so that their curvature hardly changes when heated. The contact surfaces or contact surfaces on the turbo machine housing side are therefore preferably produced with a constant, in particular concentric curvature with respect to the matter of rotation.

With a guide vane segment according to the present invention, at least at the defined operating temperature, complete contact of the functional surfaces 18 and 19 on an associated contact surface on the turbomachine housing side, in particular on a contact surface on the turbomachine housing side that is curved with a constant curvature, can be achieved or ensured.

Although exemplary embodiments have been explained in the preceding description, it should be pointed out that a large number of modifications are possible. It should also be pointed out that the exemplary designs are only examples that are not intended to restrict the scope of protection, the applications and the structure in any way. Rather, the preceding description provides a person skilled in the art with guidelines for the implementation of at least one exemplary embodiment, with various changes, in particular with regard to the function and arrangement of the described components, being able to be made without departing from the scope of protection as it emerges from the claims and these equivalent combinations of features.

List of reference symbols

10, 20

Guide vane segment according to a present invention

11

vane

12th

outer shroud

14th

leading, upstream edge of the guide vane (leading edge)

15th

rear, downstream edge of the guide vane

16

first, upstream profile

16A

radially outer projection of the first profile

16I

radially inner projection of the first profile

17th

second, downstream profile

17A

radially outer projection of the second profile

17I

radially inner projection of the second profile

18th

Functional surface of the second, downstream profile

18A

first functional surface section

18B

second functional surface section

18C

third functional surface section

19th

Functional area of the first, upstream profile

19A

first functional surface section

19B

second functional surface section

19C

third functional surface section

30th

Turbo machine housing

A.

Axis of rotation of the turbo machine, (main) machine axis

L.

Circumferential length

M1

Center of the first circle of curvature

M2

Center of the second circle of curvature

M3

Center of the third circle of curvature

R.

Radius of the circle of curvature at the defined operating temperature

R1, R4

Radius of the first circle of curvature

R2, R5

Radius of the second circle of curvature

R3, R6

Radius of the third circle of curvature

S.

Direction of flow

U

Circumferential direction

Claims (15)

1. Guide vane segment (10, 20)for a turbomachine, the guide vane segment (10,20) having at least one guide vane (11) and at least one shroud (12) comprising at least one first profile (16, 17) arranged on the shroud (12) for attachment of the guide vane segment (10, 20) on the turbomachine housing, the profile (16, 17) extending in the circumferential direction (U) at least partially over a circumferential length (L) of the gui de vane segment (10, 20) along the shroud (12) of the guide vane segment (10, 20) and having at least one functional surface (18, 19) extending at least partially in the axial direction and in the circumferential direction (U), characterized in that the functional surface (18, 19) of the profile (16, 17) has in each case two different curvatures in at least one radial plane perpendicularto an axis of rotation (A) of the turbomachine in the circumferential direction (U), at all temperatures of at least one temperature range below a defined operating temperature of the turbomachine.
2. Guide vane segment (10, 20) according to claim 1, characterized in that the guide vane segment (10, 20) has at least a first, upstream profile (16) and a second, downstream profile (17), the functional surface (19) of the first profile (16) and the functional surface (18) of the second profile (17) each having at least two different curvatures in at least one radial plane with respect to the axis of rotation (A) of the turbomachine in the circumferential direction (U), in at least one temperature range below a defined operating temperature.
3. Guide vane segment (10, 20) according to either of the preceding claims, characterized in that the first profile (16) and/orthe second profile (17) has at least one projection (16I, 16A; 17I, 17A) which extends at least partially in the axial direction and in the circumferential direction (U) and comprises an inner surface oriented inward in the radial direction and an outer surface oriented outward in the radial direction, the inner surface of the projection (16A) at least partially forming the functional surface (19) in the first profile (16) and/or the outer surface of the projection (17A) in the second, downstream profile (17).
4. Guide vane segment (10, 20) according to any of the preceding claims, characterized in that the first profile (16) and/orthe second profile (17) has a profile cross section having an inner first projection (16I, 17I) in the radial direction that extends at least partially in the axial direction and in the circumferential direction (U) and a second projection (16A, 17A) which is further outward in the radial direction and also extends at least partially in the axial direction and in the circumferential direction (U) and a web therebetween which connects the two projections (16I, 16A; 17I, 17A) and extends at least partially in the radial direction, the inner surface of the second, radially further outward projection (16A) at least partially forming the functional surface (19) in the first profile (16) and/or the outer surface (18) of the second, further outward projection (17A) in the second profile (17).
5. Guide vane segment (10, 20) according to any of the preceding claims, characterized in that at least one functional surface (18, 19) of at least one profile (16, 17) has a first functional surface portion (18A, 19A) and at least one further functional surface portion (18B, 18C; 19B, 19C), the first functional surface portion (18A, 19A) being curved with a first curvature in at least one radial plane perpendicular to the axis of rotation (A) of the turbomachine in the circumferential direction (U), in at least one temperature range below the defined operating temperature of the turbomachine, and at least one further functional surface portion (18B, 18C; 19B, 19C) being curved with a further curvature different from the first curvature in at least one radial plane with respect to the axis of rotation (A) of the turbomachine in the circumferential direction (U), in at least one temperature range below the defined operating temperature of the turbomachine.
6. Guide vane segment (10, 20) according to claim 5, characterized in that the first functional surface portion (18A, 19A) directly adjoins at least one of the further functional surface portions (18B, 18C; 19B, 19C) in the circumferential direction (U), the first functional surface portion (18A, 19A) merging, in at least one radial plane with respect to the axis of rotation (A) of the turbomachine in the circumferential direction (U), into the further functional surface portion (18B, 18C; 19B, 19C) adjoining the first functional surface portion (18A, 19A).
7. Guide vane segment (10, 20) according to any of the preceding claims, in particular according to either claim 5 or claim 6, characterized in that at least one functional surface (18, 19) of at least one profile (16, 17) has three functional surface portions (18A, 18B, 18C; 19A, 19B, 19C), specifically a first functional surface portion (18A, 19A), a first further functional surface portion (18B, 19B) and a second further functional surface portion (18C, 19C), the first functional surface portion (18A, 19A) being arranged between the two further functional surface portions (18B, 18C; 19B, 19C) in the circumferential direction (U).
8. Guide vane segment (10, 20) according to any of claims 5 to 7, characterized in that the curvature of the functional surface (18, 19) of the first functional surface portion (18A, 19A) is defined at least over part of the circumferential length (L) in the circumferential direction (U) by a first circle of curvature having a first radius of curvature (R1, R2) and lying in a radial plane with respect to the axis of rotation (A) of the turbomachine, the center point (M1) of the first circle of curvature lying on the axis of rotation (A) of the turbomachine.
9. Guide vane segment (10, 20) according to any of claims 5 to 8, characterized in that the curvature of the functional surface (18, 19) of at least one further functional surface portion (18B, 18C; 19B, 19C) is defined at least over part of the circumferential length (L) in the circumferential direction (U) by a further circle of curvature having a further radius of curvature (R2, R3; R5, R6) and lying in a radial plane with respect to the axis of rotation (A) of the turbomachine, the centerpoint (M2, M3) of the further circle of curvature being offset with respect to the axis of rotation (A) of the turbomachine.
10. Guide vane segment (10, 20) according to claim 8 and claim 9, characterized in that at least one further radius of curvature (R2, R3; R5, R6) of at least one further circle of curvature is smaller than the first radius of curvature (R1, R4) of the first circle of curvature.
11. Guide vane segment (10, 20) according to any of the preceding claims, characterized in that the functional surface (18, 19) is curved symmetrically in the circumferential direction (U) in at least one radial plane with respect to the axis of rotation (A) of the turbomachine, based on the circumferential length (L) of the functional surface (18, 19) of the guide vane segment (10, 20).
12. Guide vane segment (10, 20) according to any of the preceding claims, characterized in that the at least two different curvatures of at least one functional surface (18, 19) of at least one profile (16, 17) of the guide vane segment (10, 20) are selected such that the functional surface (18, 19) has a constant curvature in the circumferential direction (U) when the guide vane segment (10, 20) is functionally installed in a turbomachinewhen the turbomachine is in operation, at least at the defined operating temperature, which curvature is in particular defined by a circle of curvature which lies in a radial plane with respect to the axis of rotation (A) of the turbomachine and has a radius of curvature (R) of which the center point (M) lies on the axis of rotation (A) of the turbomachine.
13. Guide baffle for a turbomachine comprising at least one guide vane segment (10, 20) according to any of the preceding claims.
14. Turbomachine comprising at least one guide vane segment (10, 20) according to any of the preceding claims.
15. Method for producing a guide vane segment (10, 20) according to any of the preceding claims, characterized by the following steps:

    - producing the guide vane segment (10, 20) by means of primary molding;

    - machining at least one functional surface (18, 19)of at least one profile (16, 17) in order to introduce the at least two different curvatures of the functional surface (18, 19) in the circumferential direction (U), the first curvature being introduced into the functional surface (18, 19) over the entire length thereof in the circumferential direction (U) in a first step, and the associated further curvature being introduced into at least one further functional surface portion (18B, 18C; 19B, 19C) in at least one further step.

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