U.S. patent application number 10/002141 was filed with the patent office on 2002-07-11 for component of a flow machine, with inspection aperture.
Invention is credited to Beeck, Alexander, Wettstein, Hans.
Application Number | 20020090298 10/002141 |
Document ID | / |
Family ID | 7668442 |
Filed Date | 2002-07-11 |
United States Patent
Application |
20020090298 |
Kind Code |
A1 |
Beeck, Alexander ; et
al. |
July 11, 2002 |
Component of a flow machine, with inspection aperture
Abstract
The present invention relates to a component of a flow machine,
in particular a gas turbine, which has cooling channels (4) for a
cooling medium and also at least one inspection aperture (5)
through which an inspection of the interior of the component is
made possible. The component is distinguished in that the
inspection aperture (5) is arranged and dimensioned such that it
simultaneously fulfills the function of a dust discharge aperture
for dust or dirt particles contained in the cooling medium. By the
combination of a dust discharge aperture with an inspection
aperture, a simple inspection function is offered, without having
to provide in the component additional apertures affecting
efficiency.
Inventors: |
Beeck, Alexander; (Orlando,
FL) ; Wettstein, Hans; (Fislisbach, CH) |
Correspondence
Address: |
Robert S. Swecker
BURNS, DOANE, SWECKER & MATHIS, L.L.P.
P.O. Box 1404
Alexandria
VA
22313-1404
US
|
Family ID: |
7668442 |
Appl. No.: |
10/002141 |
Filed: |
December 5, 2001 |
Current U.S.
Class: |
416/97R |
Current CPC
Class: |
F05D 2260/607 20130101;
F01D 25/32 20130101; F05D 2260/201 20130101; F01D 21/10 20130101;
F01D 5/187 20130101; F01D 25/002 20130101 |
Class at
Publication: |
416/97.00R |
International
Class: |
F01D 005/08 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 2000 |
DE |
100 64 269.1 |
Claims
1. Component of a flow machine, in particular a gas turbine, which
has cooling channels (4) for a cooling medium and also at least one
inspection aperture (5) through which an inspection of the interior
of the component is made possible, wherein the inspection aperture
(5) is arranged and dimensioned such that it forms a dust discharge
aperture for dust or dirt particles contained in the cooling
medium.
2. Component according to claim 1, wherein the inspection aperture
(5) is dimensioned such that it makes possible the introduction of
a borescope.
3. Component according to claim 1 or 2, wherein it is constituted
as a rotating blade for a turbine, the inspection aperture (5)
being arranged in the neighborhood of the blade tip.
4. Component according to claim 3, wherein the inspection aperture
(5) runs approximately parallel to the machine axis.
5. Component according to claim 3, wherein the inspection aperture
(5) is arranged at the blade tip and runs in a radial
direction.
6. Process for the inspection and/or cleaning of the interior of a
component, embodied according to patent claim 1, of a flow machine,
in particular a gas turbine, wherein an inspection and/or cleaning
tool is introduced through the inspection or dust discharge
aperture, and an inspection and/or cleaning of the interior of the
component is carried out with the inspection and/or cleaning
tool.
7. Process according to claim 6, wherein a borescope is used as the
inspection tool.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a component of a flow
machine, particularly of a gas turbine, which has cooling channels
for a cooling medium and also at least one inspection aperture
through which an inspection of the interior of the component is
made possible, and also a process for the inspection and/or
cleaning of the interior of such a component.
[0002] For the attainment of a high efficiency factor, modern high
temperature gas turbines require a carefully devised cooling
system, particularly for the cooling of the highly loaded turbine
blades. The turbine blades have for this purpose one or more
chambers and/or channels constructed as cavities, via which a
cooling medium can be supplied to the blades from the rotor side.
As a rule, numerous cooling air bores are provided at the leading
region of the turbine blades at their forward edge, and the cooling
medium can emerge through them from the interior of the blade. A
cooling air film forms on the surface in this region and protects
the turbine blade from excessive heating. In the same way,
corresponding cooling air bores are also present at the rear edge
of the turbine blade.
[0003] A problem with such hollow components, such as turbine
blades or combustion chamber elements, which are frequently cast in
one piece, is represented by the poor accessibility of the interior
of these components. Their inspection, for example for internal
damage such as cracks, or for dirt deposits, is therefore as a rule
difficult.
DESCRIPTION OF PRIOR ART
[0004] To avoid this problem, it is known, for example from DE 198
01 804 A1, to install, in addition to the cooling air bores which
are necessary in each case, one or more inspection access apertures
in the outer wall of the turbine blade, through which bores the
blade interior can be investigated with a corresponding inspection
tool. Such an inspection aperture or inspection access aperture
also makes possible the inspection of an already built-in turbine
blade, and also the cleaning from the interior of the turbine blade
of dirt deposits which could lead to blockage of the very narrow
cooling air bores. The said document provides for the introduction
of a special cleaning tool through the inspection access aperture
for this purpose.
[0005] The present invention has as its object to develop a hollow
component of a flow machine in such a manner that both the
inspection and also a reduction of the danger of a blockage of the
cooling air bores can be implemented in a simple manner.
SUMMARY OF THE INVENTION
[0006] The object is attained with the component according to
patent claim 1. Advantageous embodiments of the component are the
subject of the dependent claims. Patent claim 6 furthermore gives a
process for the inspection and/or cleaning of the interior of a
component configured according to patent claim 1.
[0007] The component with cooling channels for a cooling medium and
also at least one inspection aperture through which inspection of
the interior of the component is made possible is characterized in
that the inspection aperture is arranged on the component, and is
dimensioned, in such a manner that it simultaneously forms a dust
discharge aperture for dust or dirt particles contained in the
cooling medium.
[0008] By a "dust discharge aperture" there is to be understood
here an aperture in the wall of the component by means of which
particles entrained in the cooling medium emerge from the interior
of the component due to their inertia. A dust discharge aperture
must therefore inevitably be arranged at a deflection of the
channel conducting the cooling medium or at the end of a dust
channel branching from this channel at a corresponding deflection.
Such dust discharge apertures are already used in components of
flow machines in order to prevent a blockage of the cooling channel
bores. An example of an embodiment of a turbine blade with such a
dust discharge aperture can be gathered from U.S. Pat. No.
4,820,122, for example. The interior of the turbine blade here has
cooling air channels which run in a serpentine manner. The
branching into the individual serpentine channels takes place
already in the region of the entry of the cooling air into the
turbine blade at the rotor. A straight channel extends radially as
a direct extension of the inlet channel and leads directly to a
dust discharge aperture at the blade tip. Particles entering with
the cooling air are conveyed, due to the cooling force [sic],
directly in a straight line radially to this dust discharge
aperture, while nearly dirt-free air can enter the other serpentine
channels without problems. The dust particles are thus conducted
out of the cooling channels into the open air [sic] through this
dust discharge aperture or this dust hole, so that the cooling air
bores proper cannot be blocked by the dust particles.
[0009] The inventor of the present invention has now discovered
that inspection access apertures, by skillful arrangement, can
fulfill the function of dust discharge apertures, or that dust
discharge apertures, by suitable dimensioning, particularly
enlargement, can serve as inspection access apertures. The dust
discharge apertures are here designed in size and position both so
that dust is favorably discharged and also an aperture with
sufficient diameter is formed in order to be able to introduce a
borescope through this aperture.
[0010] The inspection aperture or inspection bore, which at the
same time represents a dust discharge aperture, is preferably
already considered when the component is cast and not, as is the
case with the cooling air apertures, introduced by subsequent
drilling. In rotating blades, this inspection and dust discharge
aperture is preferably located in the neighborhood of the blade
tip. In order to be able to inspect these blades even in the
built-in state of the machine, these inspection and dust discharge
apertures are to be arranged approximately parallel to the machine
axis, if the inspection tool is to be introduced in the hot gas
path of the gas turbine. If the inspection tool is to be introduced
radially into the machine, a position at the blade tip is more
favorable in which the inspection and dust discharge aperture runs
radially of the machine axis. By the combination according to the
invention of the dust discharge and the inspection function in one
and the same aperture, unnecessary apertures are avoided which can
lead to an undesired loss of cooling medium and thus bring about a
loss of efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention is briefly described hereinafter using
embodiment examples in connection with the accompanying drawing,
without limitation of the general concept of the invention in any
way.
[0012] FIG. 1 is a diagram schematically showing a section through
a turbine blade which is embodied according to the present
invention; and
[0013] FIG. 2 is a further example, in cross section, of the
embodiment of a turbine blade which is embodied according to the
present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0014] FIG. 1 schematically shows in cross section a turbine blade
with a blade foot 1, platform 2, and also blade 3. Cooling air is
supplied to the turbine blade from the blade foot 1 by means of the
cavity 4 visible in the cross section. A dust discharge aperture 5
is shown at the blade tip in the forward region, i.e., in the
leading region of the turbine blade, and dirt particles entrained
with the cooling medium are discharged, due to their inertia, from
the hollow channel 4 through the said dust discharge aperture 5.
Due to the high flow speed of the cooling medium at the deflection
of the cooling channel 4 present at the dust discharge aperture 5,
the particles, due to their large mass, take the path through the
dust discharge aperture 5 and do not pass via the deflection into
the further course of the cooling channel, in which relatively
dust-free air thus flows. This cooling air flows past the pins 6
and leaves the blade by means of apertures at the rear edge, for
example, by means of a slit. The dust discharge aperture 5 is,
according to the invention, constituted with a large enough
diameter for the introduction of a borescope to be possible through
this aperture 5 into the interior of the turbine blade. In this
manner, the interior of this component can be inspected at any
time, even in the built-in state.
[0015] Finally, FIG. 2 shows a further example, in which the dust
discharge aperture 5 however runs, not radially, but in the axial
direction. In this example also, the blade foot 1, platform 2, and
turbine blade 3 can again be seen in cross section. The cooling
channel 4 runs in the same way as in FIG. 1. The dust hole 5, which
in this example runs parallel to the machine axis, makes inspection
possible with an inspection tool introduced in the hot gas path.
The mechanism of dust extraction is the same as that in FIG. 1. In
this example, the dirt particles, due to their inertia and the high
flow speed of the deflected cooling medium, take the path via the
channel 7 leading to the dust hole 5, while the cooling medium is
deflected at the branch without problems in the direction toward
the machine axis and is therefore conducted, relatively dust-free,
past the pins 6 to the cooling air apertures at the rear edge of
the blade. The dust hole 5 or the channel 7 leading to this are
hence again constituted with a large enough diameter for the
introduction of an inspection tool, particularly a borescope, to be
possible into the interior of the turbine blade.
List of Reference Numerals
[0016] 1 blade foot
[0017] 2 platform
[0018] 3 blade
[0019] 4 cooling channel
[0020] 5 dust discharge aperture or inspection aperture
[0021] 6 pins
[0022] 7 dust discharge channel
* * * * *