U.S. patent application number 10/418158 was filed with the patent office on 2004-01-01 for air and steam cooled platform of a turbine blade or vane.
Invention is credited to Tiemann, Peter.
Application Number | 20040001753 10/418158 |
Document ID | / |
Family ID | 28458916 |
Filed Date | 2004-01-01 |
United States Patent
Application |
20040001753 |
Kind Code |
A1 |
Tiemann, Peter |
January 1, 2004 |
Air and steam cooled platform of a turbine blade or vane
Abstract
A turbine blade or vane includes a platform that is cooled by
way of air and steam. The air cooling may form an open circuit,
where the steam cooling may form a closed circuit.
Inventors: |
Tiemann, Peter; (Witten,
DE) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O.BOX 8910
RESTON
VA
20195
US
|
Family ID: |
28458916 |
Appl. No.: |
10/418158 |
Filed: |
April 18, 2003 |
Current U.S.
Class: |
416/97R |
Current CPC
Class: |
F05D 2260/201 20130101;
F05D 2240/81 20130101; F01D 5/187 20130101; F02C 7/16 20130101;
F05D 2260/2322 20130101; F05D 2260/205 20130101 |
Class at
Publication: |
416/97.00R |
International
Class: |
F01D 005/08 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 18, 2002 |
DE |
10217388.5 |
Claims
What is claimed is:
1. A turbine blade or vane, comprising: a platform being both air
and steam cooled.
2. The turbine blade or vane as claimed in claim 1, wherein the air
cooling forms an open circuit.
3. The turbine blade or vane as claimed in claim 1, wherein the
steam cooling forms a closed circuit.
4. The turbine blade or vane as claimed in claim 1, wherein the
platform is air cooled in an outer region.
5. The turbine blade or vane as claimed in claim 1, wherein an
inner region of the platform is steam cooled.
6. The turbine blade or vane as claimed in claim 4, wherein the
cooling in the outer region is affected by impingement cooling.
7. The turbine blade or vane as claimed in claim 5, wherein the
cooling in the inner region is affected by impingement cooling.
8. The turbine blade or vane as claimed in claim 6, wherein the
platform includes at least one impingement cooling insert.
9. The turbine blade or vane as claimed in claim 6, wherein the
outer region has at least one impingement cooling insert.
10. The turbine blade or vane as claimed in claim 7, wherein the
inner region has at least one impingement cooling insert.
11. The turbine blade or vane as claimed in claim 1, wherein film
cooling of the platform is affected by the air cooling by way of at
least one film cooling bore.
12. The turbine blade or vane as claimed in claim 9, wherein the
impingement-cooling insert of the inner region and the
impingement-cooling insert of the outer region are formed
integrally.
13. The turbine blade or vane as claimed in claim 2, wherein the
platform is air cooled in an outer region.
14. The turbine blade or vane as claimed in claim 2, wherein an
inner region of the platform is steam cooled.
15. The turbine blade or vane as claimed in claim 3, wherein an
inner region of the platform is steam cooled.
16. The turbine blade or vane as claimed in claim 7, wherein the
platform includes at least one impingement cooling insert.
17. The turbine blade or vane as claimed in claim 10, wherein the
impingement-cooling insert of the inner region and the
impingement-cooling insert of the outer region are formed
integrally.
18. The turbine blade or vane as claimed in claim 2, wherein the
steam cooling forms a closed circuit.
19. The turbine blade or vane as claimed in claim 4, wherein an
inner region of the platform is steam cooled.
20. The turbine blade or vane as claimed in claim 18, wherein the
platform is air cooled in an outer region and wherein an inner
region of the platform is steam cooled.
Description
[0001] The present application hereby claims priority under 35
U.S.C. .sctn.119 on German patent application number 10217388.5,
filed Apr. 18, 2002, the entire contents of which are hereby
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to a cooled platform
of a turbine blade or vane.
BACKGROUND OF THE INVENTION
[0003] EP 1 126 134 A1 discloses an air and steam cooled main blade
or vane part of a turbine blade or vane.
[0004] U.S. Pat. No. 5,829,245 discloses a platform of a turbine
blade or vane which is either steam or air cooled.
[0005] The complete cooling or a turbine blade or vane including
main blade or vane region and platform and/or the root region by
means of steam cooling requires a high design outlay, entailing
cost problems. Although complete air cooling is possible, it leads
to a higher loss of compressed air as a result of the compressed
air which is removed in order to provide the cooling air.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a
platform for a turbine blade or vane which is cooled and can be
produced at low cost.
[0007] The present invention is based on the discovery that the
steam cooling can be used for regions which are simple to cool,
whereas the air cooling can be used for regions which are more
difficult to cool and, furthermore, can lead to convective cooling
of the bores and to film cooling.
[0008] In this context, it is advantageous if the steam cooling has
a closed circuit.
[0009] Since the more critical region to be cooled is in the outer
region of the platform, the outer region is advantageously air
cooled, whereas the inner region is steam cooled. Therefore, the
platform according to the invention is simultaneously air cooled
and steam cooled. The steam cooling saves on compressed air for
cooling.
[0010] The cooling action can be intensified in both the outer
region and the inner region and with air and steam cooling by
carrying out impingement cooling, in particular using
impingement-cooling inserts.
[0011] If a single piece impingement-cooling insert is used, the
number of parts which have to be fitted is reduced.
[0012] Further scope of applicability of the present invention will
become apparent from the detailed description given hereinafter.
However, it should be understood that the detailed description and
specific examples, while indicating exemplary embodiments of the
present invention, are given by way of illustration only, since
various changes and modifications within the spirit and scope of
the invention will become apparent to those skilled in the art from
this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will become more fully understood from
the detailed description given hereinbelow and the accompanying
drawings which are given by way of illustration only, and thus are
not limitative of the present invention, and wherein:
[0014] FIG. 1 diagrammatically depicts a longitudinal section
through a platform of a turbine blade or vane; and
[0015] FIG. 2 illustrates a planned view of a platform of the
turbine blade or vane.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0016] FIG. 1 shows part of a turbine blade or vane 1, in
particular a gas turbine blade or vane 1, with, for example, a
rectangular platform 4 (FIG. 2) in longitudinal section (section
perpendicular to the plane of the drawing in FIG. 2).
[0017] The turbine blade or vane 1 has a main blade or vane region
7 with a main blade or vane cavity 10 in which, by way of example,
air cooling and steam cooling of the main blade or vane region 7
takes place.
[0018] A plurality of turbine blades or vanes 1 are arranged in a
turbine and are connected to one another, for example, by a
connecting/sealing element 22 in the region of platform 4.
[0019] The platform 4 has an outer region 28 (FIG. 2, indicated by
dashed lines), which is formed along an outer periphery 29 of the
platform 4. The outer region 28 of the platform 4 surrounds an
inner region 25 of the platform 4. The outer region 28 is, for
example, air cooled. The air is taken, for example, from the
turbine compressed air.
[0020] In the outer region 28 there is, for example, at least one
impingement-cooling insert 13a in order to intensify the cooling
action. The impingement-cooling insert 13a engages, for example, in
a recess in the platform 4, i.e. in an air cooling cavity 16, the
air cooling cavity 16 being arranged on that side of the platform 4
which is remote from the main blade or vane region 7, i.e. the
underside 5.
[0021] In the impingement-cooling insert 13a there is at least one
impingement air passage 31, through which air flows into the air
cooling cavity 16. The direction of flow is indicated by arrows 37,
the cooling air flowing from the underside 5 of the platform 4
toward an outer side 6 which is located in an outer region 40.
[0022] The impingement-cooling insert 13a produces impingement
cooling of the platform 4 in the outer region 28 in a region of the
outer side 6 which is subject to thermal loads.
[0023] Starting from the air cooling cavity 16 there is, for
example, at least one air passage 34, in particular a film cooling
opening 34, in the platform 4, through which the cooling air flows
out of the air cooling cavity 16 into the outer region 40
surrounding the blade or vane 1. In this case, by way of example,
the air passage 34 is designed as a film cooling bore, resulting in
film cooling of the platform 4. The air cooling therefore forms,
for example, an open system, since the air is not returned to the
compressed air.
[0024] The outer region 28 is separated from the inner region 25 by
a separating rib 57 which, by way of example, runs all the way
around the underside 5 in the platform 4.
[0025] The steam cooling takes place in the inner region 25 of the
platform 4 below the main blade or vane cavity 10 of the turbine
blade or vane 1. In the inner region 25 there is, for example, an
impingement-cooling insert 13d which engages in a corresponding
recess 19, a steam cooling cavity 19, in the platform 4. Steam
flows out of a steam circuit of the turbine into a steam reservoir
43 through a steam inlet opening 46, in order to flow into the
steam cooling cavity 19 through at least one impingement steam
passage 49 which is present. This produces impingement cooling of
the platform 4 in the inner region 25.
[0026] The steam flows out of the steam cooling cavity 19 through a
steam passage 52 in the platform 4, for example into the main blade
or vane cavity 10 before flowing back into the steam circuit
through a steam return passage 55, so that the steam cooling forms
a closed circuit.
[0027] Other connections between steam cooling cavity 19 and steam
return passage 55 without connection to the main blade or vane
cavity 10 are also conceivable.
[0028] A cover 59 forms the steam reservoir 43, for example
together with the impingement-cooling insert 13d.
[0029] The impingement-cooling insert 13d of the inner region 25
and the impingement-cooling insert 13a of the outer region 28 may
also be formed integrally.
[0030] The impingement-cooling inserts 13a, 13d, by way of example,
rest on the separating rib 57 and are secured to it, for example by
welding.
[0031] Exemplary embodiments being thus described, it will be
obvious that the same may be varied in many ways. Such variations
are not to be regarded as a departure from the spirit and scope of
the present invention, and all such modifications as would be
obvious to one skilled in the art are intended to be included
within the scope of the following claims.
* * * * *