EP1292760A1

EP1292760A1 - Configuration of a coolable turbine blade

Info

Publication number: EP1292760A1
Application number: EP01949387A
Authority: EP
Inventors: Peter Tiemann; Michael Strassberger
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2000-06-21
Filing date: 2001-06-08
Publication date: 2003-03-19
Anticipated expiration: 2021-06-08
Also published as: CN1436275A; CN1283901C; WO2001098634A1; JP4683818B2; EP1292760B1; DE50115690D1; US20030156943A1; JP2004501311A; EP1167689A1; US6835046B2

Abstract

The invention relates to a turbine blade (1) through which cooling liquid flows and which comprises several flow channels (4, 5, 6) that are adjacently arranged in the flowing-off direction (2) of the working fluid (3). Said flow channels (4, 5, 6) extend between inflow openings (7, 8, 9), which are located on a radially inner blade foot (10), and outflow openings (11, 12, 13), which are situated opposite the blade foot in a more radially outer manner. The flow channels (4, 5, 6) extend such that the local radial flow components (15) of the resulting cooling fluid stream (14) are directed outward in a, for the most part, predominantly radial manner. A flow channel (4), which is in the front when viewing in the flowing-off direction (2), is provided whose outflow openings (11) are placed inside a touching edge (16) of the turbine blade (1). In addition, at least one rear edge channel (5, 6) is provided whose associated resulting cooling fluid stream (14) additionally comprises local cross-flow components (17) and whose outflow openings (12, 13) are placed inside a rear edge (16) of the turbine blade (1).

Description

description

CONFIGURATION OF A COOLABLE TURBINE BLADE

The invention relates to a cooling-fluid-penetrated turbine blade according to the preamble of claim 1.

Such a turbine blade through which cooling fluid flows has inner flow channels which are separated from one another by inner walls. The working fluid flows around the turbine blade. It can be a turbine blade of a gas turbine. Then the working fluid is gas. The turbine blade is inclined with respect to the incoming working fluid, so that a force component is produced in the circumferential direction of the turbine in the usual way. Therefore, the outflow direction of the working fluid is essentially the direction along the turbine blade in which the working fluid flows around it.

The type mentioned is a turbine show in the rear area of a turbine. There the working fluid is already so relaxed and cooled that only slightly cooled turbine blades are used. This means that only a lower flow of cooling fluid through the turbine is provided. Due to the low flow rate, a meandering structure of

Flow channels for the cooling fluid are not satisfactory in the case of low-cooled turbine blades. Due to the slow flow speed of the cooling fluid, it would cool too much in the initial area of a meandering flow channel and be heated up too much in the end area and consequently cool there too little. In the case of the turbine blades mentioned, the flow rate of the cooling fluid can also be too low with regard to the centrifugal forces of the turbine rotation that occur.

For this reason, the cooling fluid flows through the turbine blade simply along its radial extent. With simple Rather flow - that is to say with flow channels practically without reversal points with regard to the radial direction of the cooling fluid flow - the problems mentioned above do not occur. For this purpose, turbine blades with radial bores or with straight radial channels are known, which run from a radially inner blade root to outflow openings located further radially outward - outflow openings made in the abrading edge. The resulting cooling fluid flow then has the desired local - at any location in the flow channel - practically predominantly to exclusively radial flow components directed radially outward.

Due to the technically related minimum dimensions of both the cast core and the wall thickness, the flow and thus the cooling effect in such turbine blades is very inhomogeneous. For example, the area of a trailing edge that is to narrow in the outflow direction can generally no longer be penetrated by a radial flow channel due to the minimum dimensions mentioned, which are caused by the manufacturing process. The overhanging rear edge overheats. Furthermore, there are restrictions - in particular due to the above-mentioned minimum dimensions - in the geometry of the usually large turbine blades in the rear area of the turbine.

It is an object of the present invention to provide a turbine blade which, despite a low cooling fluid flow, is adapted to the technical requirements for slightly cooled turbine blades with regard to their geometry and which nevertheless permits largely homogeneous cooling, in particular in the peripheral zones.

This object is achieved by the features of claim 1.

The invention offers the advantage that it permits homogeneous cooling of the turbine blade, in particular in the area of the edges. The area is particularly problematic here of the trailing edge duct, in which the flow requirements, for example, require a narrowing of the turbine blade.

The advantage mentioned is achieved in that one or more trailing edge ducts are provided, the cooling fluid flow of which have local crossflow components at predetermined locations and in which outflow openings are introduced into a trailing edge of the turbine blade. The use of the trailing edge as the area for the outflow of cooling fluid opens up a large variety of design options for low-cooled turbine blades that were previously not accessible.

In this way, the trailing edge channels can - at least partially - discharge their cooling fluid via the outflow openings which are introduced into the trailing edge. This also creates more free space for the channels located in the outflow direction in front of the trailing edge channels. Outflow openings - in particular at the abrading edge - which were previously acted upon by the trailing edge ducts can now be used to discharge cooling fluid from flow ducts located in front of the trailing edge ducts.

A threefold efficiency is achieved: this makes it possible for the first time to cool the trailing edge of a turbine blade according to the invention effectively and homogeneously and at the same time to have a thin trailing edge (in the sense of improved aerodynamics). Furthermore, a natural outflow of the cooling fluid is achieved for the trailing edge ducts, which allows the front flow ducts located in front of the trailing edge ducts to be adapted to the technical requirements in their geometry and in particular in their outflow behavior.

This means that, for example, front flow channels act on more outflow length along the contact edge can than was previously the case. Since the trailing edge channels are on the one hand further shifted in the outflow direction to the trailing edge and, on the other hand, dodge due to their curved shape, the front flow channels located in front can fill the free space created. Due to the local cross-flow components of the trailing edge channels, the front flow channels can also be bent such that they also have local cross-flow components. This results in a different use of space within the cooling volume of the turbine blade with better use of the cooling air.

For the first time, turbine blades in the rear area of the turbine - that is, low-cooled turbine blades - can also be designed with the least to vanishing geometry restrictions. For example, it is a well-known requirement (for reasons of strength and reasons of casting) that the turbine blade narrows in the radial direction away from the blade root. Since the outflow openings of the trailing edge are used, the remaining, in particular front and middle, flow channels can expand in this direction with respect to their extension parallel to the outflow direction and thus the thickness decrease in the radial direction by widening parallel to the outflow direction and use of several outflow openings of the abrading edge compensate for a flow channel. As a result, with the best possible efficiency of the turbine, a practically constant internal cross section of the flow channels can be achieved combined with a slim profile. This is only possible with the invention, since the additional space is only made possible by the now opened outflow openings on the contact edge and the curved course of the flow channels. In addition, a curved profile shape for optimizing the aerodynamics (edge zone effects) is possible - in contrast to the drilled blade - with the possibility of cooling the rear edge, in contrast to previous geometries. Preferred embodiments of the present invention are described in the subclaims.

The flow channels can be shaped in such a way that cross-flow components are present in the outflow direction and in the opposite direction. Preferably, however, only or predominantly cross-flow components are provided in the outflow direction. The cross flow components cause a flow through the trailing edge that was not previously available. By using the cross-flow components mentioned, this becomes

Cooling fluid also automatically led to the outflow openings in the rear edge.

It is preferred that a trailing edge duct and / or a front flow duct bend / bend at least in sections, in particular with its outer radial sections, from the radial direction in the outflow direction.

In order to avoid dead zones and to reduce the overall flow resistance so that the entire available cooling volume is used effectively, it is provided that the turning sections are rounded. The bending sections then run without edges with curvature.

There can be several trailing edge channels. In particular, the last trailing edge channel seen in the outflow direction is provided practically exclusively with outflow openings made in the trailing edge. On the basis of the inventive idea of using crossflow components and providing outflow openings in the rear edge, this is the most effective solution and as few - preferably no - outflow openings other than those of the rear edge are acted upon and thus occupied.

The last trailing edge channel can therefore also end at a radial distance radially on the inside in front of the brushing edge. According to the invention, this channel does not need any outflow at all. > 00 MMH ¹ I- ¹ π o Cn o Cπ o Cπ

ιQ N ιQ 3 σ co H = s CΛ O? r N φ er ^• H co ≤ o *? T iE Φ CL <! tc>><INI t CL O:

03 d 03 H- Ω φ H- H- 3- DJ t. Φ H- Φ d DJ rt Φ DJ Φ DJ H- μ- μ- O μ- dd O d μ- Φ Hi lf ιQ Φ - ^■ CΛ 3 H- Φ 3 Φ 3 H- 3 3 3 co H H- 3 H 3 3 3 KQ ii 3 CΛ o H co 3 li H

CΛ H- CΛ 3 Ω 3 3 DJ. CΛ φ ΪV - o H- O: rt 3 3 rt ^ Q rt CΛ co tr DJ: ω co 3

DJ s: O DJ H- tT t Φ • - ^■ Ω er D ⁾ rt DJ 3 Φ Φ Φ Φ μ- Φ Φ et rt DJ rt μ- d

Φ "Η d rt rt Φ φ 3 ^* Φ O: 3 H - ¹ O: li? 3 H tr Ω HHH 3 N Ω φ 3

CΛ H- H Hl rr H C σ Φ H- Hl SU O: Hl DJ DJ? V H tr Φ? O- O: CL tr Hl u3

CΛ ιQ DJ Φ Φ H- r + 3 α Hi - ^■ 3 5 Hi H- 3 CΛ DJ DJ 3 DJ 3 3 Φ μ- rt Hi Φ

N Φ H? T tr Ό H- H Φ H Φ 3 O: Φ 3 3 3 3 Ω> 3 O: O: 3 Ω h- ¹ Φ 3 φ O r + Φ HJ rt Φ QL 3 dd Hl H- d 3 N rt tr d cn rt Hl Hi tr μ-? T

, -r S. tP H- N DJ P Cfl ^ 3 Φ 3 3 Hi rt 3 Φ σ d Φ r co rt Φ Hi Hl co Ω rt μ-

3 Φ o d:? Φ d 3 3 CΛ ιQ α 3 Φ u3 3 Φ H 3 ω H 3 3 3 Φ? V tr μ- 3

3 H- Ω uq rr 0 H l-i rt rt d H Φ H-; r O rt 0:? r d d μ- DJ <

<v H- CΛ "H H- Φ tr 3 Ω Φ H α 3 3 (- 'CΛ <DJ μ- h 3 DJ 3 3 3 3 a Φ CL

H ιQ rr H- CΛ H Φ H t H- O: Φ uQ DJ H- O φ 3 3 O: d 3 ιQ ιQ 3 Φ Φ o Φ • <. Ω Ω 3 DJ iQ H- 3 3 J 3 Φ d d Φ H- H DJ C 3 3 DJ Φ Φ co ^ H

NH Φ 3- t (- ¹ iQ Φ co N d ω 3 E 3 tQ Φ Hl O: u3 H- 3 3 φ o φ DHO D> Φ - r + Φ 3 h Φ C Φ Hl co Φ μ- ≤ h

3 DJ μ- 3 d: π d φ H Q H- DJ 0! 3 3 CO lQ s: σ Hi? R tr DJ DJ H 3 μ- 3 3 rt Φ αi Φ tr DJ o N 3 3 CΛ o d CL s: d μ- d 3 DJ μ- d ^ H ιQ co

CΛ Ω CΛ φ ιQ d DJ Φ? r + H- Hi φ Φ Φ 3 H h d 3 Hl CO col-J -V Φ rt

3 ^" H Φ Φ Φ 3 3 DJ DJ s; H- H H- -a L Ω 3 DJ α o DJ d tr H

Φ N d CΛ H φ 3 3 Φ Φ Φ O tr ιQ Φ Φ DJ s: CL 3 d Φ ω s: Φ JU: er d: H <CΛ: H- H- U3 h H- Φ CΛ Φ Φ rt μ - do μ- υ--! 3 μ-

DJ H CO H- H ^" 3 Φ DJ rt- l- ¹ 3 co Φ DJ 3 rt μ- Φ 3 d ω Ω tr J co U3 Hj ιQ 3 co CΛ o-- φ Φ HO: H 3 H Φ d Φ 3 α α Φ 3 μ- 3 Λ rt tr ιQ? Φ N Ω μ- 3 CO f + ιQ σ O: 3 σ H 3 H- 0- Φ 3 ^* 3 DJ CL d H CL DJ

.3 H- tr ιQ d ιQ d l- ¹ H- 3 d Ω Φ DJ H- H Φ s: Φ d DJ μ- μ- CL DJ Φ 3

0 ⁾ lQ 3 tr 3 DJ - • H- 3 Φ d H - ^ <Φ 3 Φ 3 Hi Φ o M 3 3 d CL H rt

3 H- SU ιQ 3 rt- s Ω α H 3 <! Ω ιQ INI H CL μ- SS μ- μ- μ- h Φ Φ σ.

3 na rt- li co N H- H- 3 ^ c QO 3- Φ s: H- α W φ Φ Ω co Φ 3 3 α Ω co m. rt- H r + Φ ≤ Φ φ h Φ 3 CΛ CΛ H σ 3 ^{^} H- 3 d H- rt tr o μ- φ CL μ- μ- tr d

Φ o CΛ H- ls 3 ιQ r + ^ iQ li Φ CO H 3 N φ μ- ¹ o 3 Φ o Φ Φ iQ CL H ö

3 N DJ lO α iT <φ • Φ DJ Φ d 3 Ω fi Ω rt rt: H Ω rt 3 o Φ Φ tr DJ

Φ tr d Φ DJ: 3 CL α 3 CΛ Ω t H- 3 "Φ Φ - = tr d H- ¹ w - tr H μ- 3

H 3 s Φ H 3 α d H- DJ: Φ 3 "Φ φ Φ ιQ i-i G Φ μ- G o μ- 3 Φ 3 μ-

3 rt Φ n CΛ ιQ Φ h Φ Φ 3 ^J 3 3 Φ ^ ffi <! r 3 CL 3 tr tr 3 CΛ 3 H Φ ht

3 H- co rt Φ Ω 3 Φ Φ H- W 3 ^* DJ H- O Φ μ- rt Φ Φ rt rt d 3

Φ d π Ω DJ "(i- α 3 3 3 ffi H- Φ 3 3 H Φ φ H Φ H Φ H cn ≤:

3 3 3 ' ^* 3 Φ Φ Φ H- φ 3 3 rt rt C- ιQ li QH Φ H tr Ω μ-

Λ α d 3 H- Hi α H CΛ H 3 3 rt Φ Φ 3 DJ DJ μ- ^ DJ? μ- μ- tr l-i

3 H- φ 3 Hl H- DJ φ 3 f + Φ (0 M φ 3 CL 3 DJ 3 H D Hi tc 3 DJ α

H- ιQ rt CΛ Φ Φ Φ N O: H- H- 3 φ H Φ? V 3 ιQ μ- 3 ιQ DJ 3 Λ- μ- Φ d

H 3 φ r + CΛ Hl φ 3 Φ H Φ ΪV tr, H- DJ DJ. rt CL et DJ 3 Hi Φ ω co 3 co α rt M Hi • 3? rt DJ H- 3 3 φ Φ h- ¹ μ- Φ N μ- Φ 3 rt 1 Φ ι-i

O σ DJ Φ CΛ H- H 3 DJ tr DJ N 3 3 ιQ rt Hl Φ 3 s: DJ rt Φ cn tT Φ σ tr CΛ et <1 Hi od H α φ 3 rt rt- rt Φ Φ Hl CL K μ - H Φ Φ φ rt

3 cn Φ S. H φ H- μ. 3 - ¹ H- H rt Φ Φ Φ tr 3 Φ φ d ffi DJ CΛ μ-? H 1

H- o rt Φ CΛ 0: 3 Φ LQ Φ ω φ Φ 3 ι-i H? V μ- li μ- 3 Ω 3 Φ DJ 3 Φ rt 3 left H- ^■ 3 EP H- 3 Φ? DJ DJ rt Ω Ω 3 DJ td LQ μ- 3 O: μ- μ- rt DJ Ω hd 3 σ d ω s; Ω WK H- DJ Ω 3 H- tr tr rt Φ li Φ 3 rt ιQ 3 3

01 φ uα - O: 3 3 3 DJ 3 rt- DJ t DJ H- 3 3 p- DJ <! t ιQ φ 3 o tr tQ Φ cn Φ

• H Φ d 3 ι Φ iQ H rt H 3 3 3 ^ rt rt • φ H tr H Φ 3 μ- tr φ 3 3 d co 3? Φ O: N DJ rt Φ Φ Φ ιQ tr? CL Φ ιQ DJ σ f Ω φ tr

-Q 3? R Λ φ φ H 3 s: H ¹ Φ tr 3 H Φ σ Φ DJ Φ μ- Φ Ω ι-i DJ tr co Φ s: <Φ iQ DJ dl P- er d 3 H- H li ? DJ 3 DJ 3 3 3 tr tr DJ 3 rt o cn

Φ O 3 CΛ 3 φ 1 rt- H 3 ιQ CΛ? V? PJ DJ d α d α CL rt Φ Φ rt Ω DJ • 3 O

3 H? SD H O ιQ Ω SD DJ Ω 3 co H- rt d Φ Φ M 3 3 Φ tr H CL 3

H- 1 DJ 1 H- 1 3 ^{^} 3 3 DJ 1 N Φ CL rt Φ I 1 1 o 3 1 Φ 3 I er H- ¹ rt Ω 1 φ Φ H 3 Φ tr H Φ

The resulting effective total cross-sectional area of the inflow openings is preferably equal to the total cross-sectional area of the outflow openings of a flow channel, the respective total cross-sectional area corresponding to the inner cross section of the associated flow channel.

A turbine blade according to the invention is slightly cooled, i.e. executed without meandering structure of the flow channels. It is used for the rear area of a turbine and / or for low-cooled turbines / turbine blades.

The invention is explained in more detail with reference to exemplary embodiments shown in the figures. Show it:

1 shows a perspective top view of a turbine blade according to the invention with a blade root, the internal flow channels being shown hidden, FIG. 2 shows a longitudinal section through the turbine blade according to FIG. 1.

The reference numerals in the figures denote the same design features. The invention is described below with simultaneous reference to FIGS. 1 and 2.

The turbine blade 1 is surrounded by the working fluid 3 - which is only partially shown as an example in FIG. 1 - in the outflow direction 2, as a result of which the work is generated or the turbine is driven. The cooling fluid 31 - which is also shown by way of example and in detail in FIG. 2 - flows through the turbine blade 1 along the flow channels 4, 5, 6. As a result, the turbine blade 1 is cooled. The cooling fluid 31 can be (cooled) air, for example. Such a turbine blade 1 has a blade root 10 which is inserted into a corresponding groove in the turbine disk (not shown here) and fastened there. The inflow openings 7, 8, 9 shown are aligned with corresponding openings in the turbine disk. Through this, the cooling fluid 31 is supplied to the flow channels 4, 5, 6.

The flow channels 4, 5, 6 run between the inflow openings 7, 8, 9 on the radially inner blade root 10 and, on the other hand, outflow openings lying further radially outward

11,12,13. They run without reversal points with respect to the radial direction 20, i.e. practically reversible. The cooling fluid 31 therefore only flows through the radial extent of the turbine blade 1 in each flow channel 4, 5, 6 simply. The resultant points at each point of a flow channel

Cooling fluid flow 14 locally practically exclusively radially outward — and not approximately inward — radial flow components 15 (see FIG. 2). All radial flow components 15 thus point away from the center of the turbine rotation. A turbine blade 1 is also slightly cooled and is therefore suitable for realizing the invention if its flow channels practically predominantly have radial flow components 15 directed radially outwards.

The flow channels 4, 5, 6 separated by the inner walls 30 are curved in the exemplary embodiment shown in such a way that the resulting cooling fluid flow 14 has, in addition to the radial flow components 15 mentioned, local cross-flow components 17.

For clarification, the resulting cooling fluid flow 14 in the flow channels 4, 5 is schematically broken down into a radial flow component 15 and a cross flow component 17 in FIG. 2. The radial flow components 15 all point radially outward. As a result, the cooling fluid flow 14 is practically reversible with respect to the radial direction 20. In the exemplary embodiment, this applies to all flow channels 4, 5, 6.

There is a last trailing edge channel 6 seen in the outflow direction. This (as well as the flow channels 4, 5) bends with rounded bending sections 21 from the radial direction 20 in the outflow direction 2. The course of the flow channel 6 is thereby curved in the direction of the rear edge 18.

Due to the curvature, the cross-flow components 17 are directed locally in the outflow direction 2 at each point. As a result, the cooling fluid 31 of the last trailing edge channel 6 is supplied to the outflow openings 13 in the trailing edge 18, which are located further radially on the inside.

Two trailing edge channels 5, 6 are shown in the figures. Both trailing edge channels 5, 6 open into the outflow openings 13, 23 in the trailing edge 18. The radially continuous trailing edge channel 5 opens into the outflow openings 23, which are more radially outward and are introduced into the trailing edge 18 and at the same time into an outflow opening 12 which is introduced into the abrading edge 16 In order that the outflow openings 23, which are further radially outward, can be acted upon by the cooling fluid 31 in the radially continuous trailing edge duct 5, the last trailing edge duct 6 seen in the outflow direction 2 ends at a radial distance 22 radially inward in front of the abutting edge 16. As a result, the outflow openings 23 remain through the last trailing edge channel 6 unused.

The trailing edge channels 5, 6 communicate via an opening 24 which is arranged in the middle (with respect to the radial direction 20) of the radially continuous trailing edge channel 5 and at the radially outer end of the last trailing edge channel 6.

The flow channel 4 seen in the outflow direction 2 widens outward in the radial direction 20 its extension in the outflow direction 2 (ie the width). The front flow channel 4 is also curved such that local, resulting cross-flow components 17 are present. The inner walls 30, which separate the flow channels 4, 5, 6 from one another, are of practically the same thickness over the entire radial extent of the turbine blade 1. The front flow duct 4 therefore follows the trailing edge ducts 5, 6 and nestles against them, so that the interior of the turbine blade 1 is practically completely penetrated by the flow ducts 4, 5, 6.

Another new feature of the invention is that the trailing edge channels 5, 6 practically penetrate the area of the trailing edge 18 of the turbine blade 1 except for a remaining outer wall thickness. This wall thickness - as well as the size of the cast core of a cast turbine blade, i.e. the size of the cavities - are limited downwards by the technical parameters of the manufacturing process. The enforcement of the trailing edge 18 also results in a homogeneous cooling of the turbine blade 1 that encloses the trailing edge 18.

1 that the turbine blade 1 narrows outward in the radial direction 20 and at the same time in the outflow direction 2. The inner cross section 25 of the flow channels 4, 5, 6 should remain approximately the same, however, practically over the entire length 26 of a flow channel 4, 5, 6. This is achieved by the invention for the first time for turbine blades 1 in the rear area. As a result, the local, resulting, effective inner cross section 25 is practically the same over the entire length 26 of a flow channel 4, 5, 6, except for cross-sectional deviations which are negligible with respect to the flow resistance of the flow channel 4, 5, 6. This is shown in FIG. 1 using the example of the flow channel 4. to IO ¹ t- ¹ o cπ o Cπ o cπ

Claims

claims

1. Turbine blade (1) through which cooling fluid flows, with a plurality of flow channels (4, 5, 6) which are arranged adjacent in the outflow direction (2) of the working fluid (3) and which are located between inflow openings (7, 8, 9) on a radially inner blade root (10) and, on the other hand, outflow openings (11, 12, 13) lying further radially on the outside, with a cooling fluid flow (14) that is practically reversible with respect to the radial direction (20), and with a front flow channel (4), seen in the outflow direction (2), whose outflow openings (11) are introduced into a scraping edge (16) of the turbine blade (1), characterized in that at least one trailing edge duct (5, 6) is present, the cooling fluid flow (14) of which has local cross-flow components (17) at predetermined points and at the outflow openings (12, 13) are introduced into a rear edge (16) of the turbine blade (1).

2. Turbine blade according to claim 1, so that cross flow components (17) are present in the outflow direction (2).

3. Turbine blade according to one of claims 1 or 2, characterized in that a trailing edge channel (5,6) and / or a front flow channel (4) at least in sections, in particular with its / its outer radial sections (19), from the radial direction ( 20) turn in the outflow direction (2).

4. Turbine blade according to claim 3, characterized in that rounded bending sections (21) are present.

5. Turbine blade according to one of claims 1 to 4, d a d u r c h g e k e n n z e i c h n e t that several trailing edge channels (5,6) are available.

6. turbine blade according to one of claims 1 to 5, d a d u r c h g e k e n n z e i c h n e t that seen in the outflow direction (2) last trailing edge channel (6) exclusively in the trailing edge (18) introduced outflow openings (13).

7. Turbine blade according to claim 6, so that the last trailing edge duct (6) ends at a radial distance (22) radially inward in front of the contact edge (16).

8. Turbine blade according to one of claims 1 to 7, characterized in that a radially continuous trailing edge channel (5) is present, both in the abrading edge (16) introduced outflow openings (12) and in the trailing edge (18) introduced outflow openings ( 23).

9. Turbine blade according to claims 6, 7 and 8, characterized in that the last trailing edge duct (6) radially inside, in the trailing edge (18) introduced outflow openings (13) and that the radially continuous trailing edge duct (5) lying radially further outside, has outflow openings (23) made in the rear edge (18).

10. Turbine blade according to claim 9, characterized in that the last trailing edge duct (6) communicates via an opening (24) with the radially continuous trailing edge duct (5).

11. Turbine blade according to one of claims 1 to 10, d a d u r c h g e k e n n z e i c h n e t that the local, effective internal cross-section (25) practically over the entire length (26) of a flow channel (4,5,6) except for the flow resistance of the

Flow channel (4.5 6) negligible cross-sectional deviations (27) is the same size.

12. Turbine blade according to claim 11, d a d u r c h g e k e n n z e i c h n e t that the

Cross-sectional deviations (27) less than 20 percent, in particular less than 10 percent of the inner cross-section (25).

13. Turbine blade according to claim 11 and 12, characterized in that the resulting effective total cross-sectional area (28) of the inflow openings (7,8,9) is equal to the total cross-sectional area (29) of the outflow openings (11,12,13,23) of a flow channel (4th , 5, 6), and that the respective total cross-sectional area (28, 29) corresponds to the inner cross-section (25).

14. Use of a turbine blade according to one of claims 1 to 13 for the rear region of a turbine and / or for a slightly cooled turbine.