U.S. patent application number 11/632018 was filed with the patent office on 2007-09-13 for method and device for monitoring the cooling air system of a turbine.
Invention is credited to Andreas Luttenberg.
Application Number | 20070212212 11/632018 |
Document ID | / |
Family ID | 34925695 |
Filed Date | 2007-09-13 |
United States Patent
Application |
20070212212 |
Kind Code |
A1 |
Luttenberg; Andreas |
September 13, 2007 |
Method And Device For Monitoring The Cooling Air System Of A
Turbine
Abstract
Disclosed are a method and a device for monitoring the cooling
air system of a turbine, cooling air being fed to at least one
series of blades of the turbine. According to the method and the
device, an air pressure is determined in at least one cooling air
reservoir from which the cooling air is discharged and is fed to
the series of blades. Preferably, the air pressure that is detected
by means of a pressure sensor is transmitted in a wireless manner
to an evaluation unit.
Inventors: |
Luttenberg; Andreas; (Essen,
DE) |
Correspondence
Address: |
SIEMENS CORPORATION;INTELLECTUAL PROPERTY DEPARTMENT
170 WOOD AVENUE SOUTH
ISELIN
NJ
08830
US
|
Family ID: |
34925695 |
Appl. No.: |
11/632018 |
Filed: |
July 7, 2005 |
PCT Filed: |
July 7, 2005 |
PCT NO: |
PCT/EP05/53240 |
371 Date: |
January 9, 2007 |
Current U.S.
Class: |
415/116 |
Current CPC
Class: |
F01D 5/085 20130101;
F02C 7/08 20130101; F01D 25/12 20130101; F01D 21/003 20130101; F05D
2270/3011 20130101; F05D 2260/607 20130101; F05D 2260/80 20130101;
F05D 2270/301 20130101 |
Class at
Publication: |
415/116 |
International
Class: |
F04D 31/00 20060101
F04D031/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 9, 2004 |
EP |
04016249.7 |
Claims
1.-8. (canceled)
9. A method for monitoring a cooling air system of a turbine having
a series of rotor blades, comprising: providing a cooling air
reservoir located in the interior of a rotating rotor blade shaft
of the turbine; determining an air pressure in the cooling air
reservoir; extracting cooling air from the reservoir; feeding
cooling air to the series of rotor blades; and wirelessly
transmitting a current value of the air pressure to an evaluation
unit.
10. The method as claimed in claim 9, wherein the cooling air
reservoir is arranged as a ring about a turbine axis.
11. The method as claimed in claim 9, wherein the cooling air
reservoir is supplied with compressed air from a compressor and
communicates directly with the series of rotor blades via a cooling
air duct.
12. The method as claimed in claim 9, wherein the air pressure is
determined by at least one pressure sensor.
13. The method as claimed in claim 9, wherein a blockage of a
cooling air inlet opening enveloped by at least one turbine blade
is detected based upon an increasing air pressure in the
reservoir.
14. The method as claimed in claim 9, wherein a blockage of a
cooling air outlet opening enveloped by at least one turbine blade
is detected based upon an increasing air pressure in the
reservoir.
15. The method as claimed in claim 9, wherein a blockage of a
turbine blade cooling air duct is detected based upon an increasing
air pressure in the reservoir.
16. The method as claimed in claim 9, wherein a blockage of a
cooling air duct physically connected to the reservoir is detected
based upon an increasing air pressure in the reservoir.
17. A device for monitoring a cooling air system of a turbine,
comprising: a turbine having a series of rotor blades fed with
cooling air; a cooling air reservoir located in a rotor blade
shaft, the cooling air extracted and fed from the shaft to the
series of rotor blades; a pressure sensor arranged in the cooling
air reservoir that determines a current air pressure of the cooling
air pressure; and a wireless transmitter that transmits the current
air pressure to an evaluation unit via the pressure sensor.
18. The device as claimed in claim 17, wherein the cooling air
reservoir is arranged in the form of a ring about a turbine
axis.
19. The device as claimed in claim 17, wherein a compressor
supplies the cooling air reservoir with compressed air.
20. The device as claimed in claim 17, wherein the cooling air
reservoir communicates via a cooling air duct directly with the
series of rotor blades.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International
Application No. PCT/EP2005/053240, filed Jul. 7, 2005 and claims
the benefit thereof. The International Application claims the
benefits of European application No. 04016249.7 EP filed Jul. 9,
2004, both of the applications are incorporated by reference herein
in their entirety.
FIELD OF INVENTION
[0002] The invention relates to a method and a device for
monitoring the cooling system of a turbine, cooling air being fed
to at least one series of blades of the turbine.
BACKGROUND OF INVENTION
[0003] In gas turbines, a very hot drive gas which is generated in
a combustion chamber is applied to the turbine blades.
[0004] In order to avoid damage to the turbine blades, a cooling
air system is usually provided by means of which cooling air for
cooling the turbine blades is introduced into the interior of the
turbine blades.
[0005] The turbine blades are therefore usually fashioned as a
hollow body which has a number of cooling air ducts in order to
convey the cooling air in the interior of the turbine blade in a
targeted manner.
[0006] In this process a cooling air flow is, for example, diverted
several times inside the turbine blade and exits the turbine blade
at cooling air outlet openings.
[0007] The cooling air ducts and/or the cooling air inlet and/or
outlet openings of the turbine blades usually have small diameters
so that they tend to become blocked as a result of impurities in
the cooling air.
[0008] Blocked cooling air openings and/or cooling air ducts of the
turbine blades are in many cases the cause of overheating of the
turbine blades, particularly in the area around the cooling air
outlet openings.
[0009] The turbine blades, more particularly their heat-resistant
ceramic coating, can be destroyed by such overheating.
[0010] In order to avoid such damage it is known to make provision
in a turbine for maintenance cycles in which as a rule at least
partial dismantling is required in order to be able to ascertain
through visual inspection any looming damage or damage which has
already occurred to turbine blades.
[0011] Such known methods are very costly since the turbine has to
be taken out of service for this purpose, which results in
production outages. In addition to this, the maintenance measures
themselves are very time-consuming and costly, in particular
because of the at least partial dismantling of the turbine that is
usually required.
[0012] Furthermore, maintenance measures of this kind may reveal
that no damage is present at all and the measure was not therefore
necessary or that far advanced damage is already present, the scale
of which could have been prevented if the damage had been detected
earlier.
SUMMARY OF INVENTION
[0013] An object of the invention is therefore to indicate an
improved method and a device for monitoring the cooling air system
of a turbine, wherein cooling air is fed to at least one series of
blades of the turbine.
[0014] The object is achieved according to the invention by means
of a generic method, an air pressure being determined in at least
one cooling air reservoir from which the cooling air is extracted
and fed to the series of blades.
[0015] It is possible by this means to detect blockages of cooling
air inlet openings and/or cooling air outlet openings and/or
cooling air ducts at an early stage, which helps to avoid damage to
the turbine blades.
[0016] The air pressure in the cooling air reservoir is a measure
of the extent to which the flow of cooling air through the turbine
blades may already be impaired.
[0017] In one embodiment, the cooling air reservoir is arranged in
a turbine housing of the turbine. It is particularly preferable if
this cooling air reservoir is arranged in the form of a ring about
a turbine axis.
[0018] Such a rotationally symmetrical design of the cooling air
reservoir enables uniform cooling of the turbine blades which are
likewise arranged in a rotationally symmetrical manner.
[0019] In a particularly preferred embodiment, the cooling air
reservoir is supplied with compressed air from a compressor and it
communicates directly with the series of turbine blades via a
cooling air duct.
[0020] In this embodiment, the cooling air reservoir is arranged in
very close proximity to the series of blades to be cooled, which
leads to efficient cooling with little loss of pressure in the
cooling air flow.
[0021] The air pressure is preferably determined by means of at
least one pressure sensor which is arranged in the cooling air
reservoir.
[0022] It is particularly preferred if a current value of the air
pressure is transmitted wirelessly to an evaluation unit.
[0023] In a further preferred embodiment, it is concluded, due to
an increasing air pressure in the cooling air reservoir, that there
is a blockage of at least one cooling air inlet or/and outlet
opening enveloped by at least one turbine blade or/and of a turbine
blade cooling air duct or/and of the cooling air duct thereof.
[0024] A blockage of one of the specified means leads, through
back-pressure from the cooling air which has been fed, to a rise in
the air pressure; this is a clear indication of the presence of a
blockage.
[0025] With regard to the device, the object is achieved according
to the invention by means of a device for monitoring the cooling
air system of a turbine, wherein cooling air can be fed to at least
one series of blades of the turbine, said device comprising at
least one pressure sensor arranged in a cooling air reservoir, it
being possible for the cooling air to be extracted from the cooling
air reservoir and fed to the series of blades.
[0026] Preferably, the cooling air reservoir is arranged in a
turbine housing of the turbine.
[0027] In one embodiment, the cooling air reservoir is arranged in
the form of a ring about a turbine axis.
[0028] It is particularly preferable if the device comprises
furthermore a compressor for supplying the cooling air reservoir
with compressed air, the cooling air reservoir communicating
directly with the series of turbine blades via a cooling air
duct.
[0029] Particularly advantageously, the pressure sensor is enhanced
for wirelessly transmitting a current air pressure to an evaluation
unit.
BRIEF DESCRIPTION OF THE DRAWING
[0030] An exemplary embodiment of the invention will be described
in more detail below with reference to the FIGURE, in which:
[0031] FIG shows a device according to the invention for monitoring
the cooling system of a turbine.
DETAILED DESCRIPTION OF INVENTION
[0032] The FIGURE shows an inventive device 1 by means of which a
cooling system 3 of a turbine 5 can be monitored.
[0033] The turbine 5 comprises in the present exemplary embodiment
four series of turbine blades 7 which are embodied as rotor blades.
The series of stator blades which is usually arranged, in the
direction of flow of the heating gas, upstream of each series of
rotor blades is not shown in the exemplary embodiment.
[0034] In connection with the present invention, the cooling air
system 3 can also be provided in addition for cooling the series of
stator blades.
[0035] The most severely temperature-stressed series of blades 7
are the series of blades lying, in the direction of the heating
gas, closest to the hot drive gas.
[0036] The cooling air system 3 in the present exemplary embodiment
is therefore configured for cooling the first two series of blades
7. It is, however, also conceivable for the cooling system 3 to be
configured only for one of the series of blades 7, in particular
for the first series, or else for several or all series of blades
7.
[0037] The turbine blades of the series of blades 7 are fashioned
as hollow bodies into which cooling air 9 is introduced.
[0038] For this purpose, the turbine blades usually have internally
a number of turbine blade cooling air ducts in which the cooling
air 9 is conveyed. Furthermore, the turbine blades comprise cooling
air inlet and cooling air outlet openings.
[0039] The details specified with regard to the conveying of
cooling air in the turbine blades are not shown in detail in the
FIGURE.
[0040] The cooling air 9 is provided by a compressor 19 which
supplies cooling air reservoirs 11 with compressed air as cooling
air 9.
[0041] The cooling air reservoirs 11 are arranged in a rotationally
symmetrical manner and in the form of a ring about a turbine axis
17 and inside a turbine housing 15.
[0042] To determine the air pressure in the cooling air reservoirs
11, at least one pressure sensor 13 is provided in each case, said
pressure sensor being connected, preferably wirelessly, to an
evaluation unit 23.
[0043] The cooling air 9 provided in the cooling air reservoirs 11
for the series of blades 7 is conveyed via cooling air ducts 21
into the series of turbine blades 7.
[0044] A blockage of the cooling air ducts 21 or/and of cooling air
inlet openings of the turbine blades or/and of cooling air outlet
openings of the turbine blades or/and of turbine blade cooling air
ducts is detected by means of the pressure sensor 13, since such a
blockage leads to back-pressure in cooling air 9 in at least one
cooling air reservoir 11, which in turn translates into rising air
pressure in the respective cooling air reservoir 11.
[0045] The evaluation unit 23 is enhanced to detect such a rise in
the air pressure and, for example, to generate a corresponding
alarm or fault message for the personnel operating the turbine
5.
[0046] In connection with the invention, the absolute air pressure
of the cooling air 9 or a change therein is preferably determined
in at least one cooling air reservoir 11. With regard to the first
series of rotor blades, the air pressure is measured between the
central hollow shaft and the first turbine wheel disk;
correspondingly, the air pressure in respect of the second series
of rotor blades is measured between the first and the second
turbine wheel disk.
* * * * *