US 7,887,234 B2Granted

Maximum blade surface temperature estimation for advanced stationary gas turbines in near-infrared (with reflection)

AssigneesSiemens Aktiengesellschaft, Siemens Energy, Inc.

InventorsVinay Jonnalagadda, Dennis H. Lemieux, Visvanathan Ramesh, Matthias Voigt

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Abstract

Methods for maximum scene surface temperature estimation for blades with reflective surface properties in advanced stationary gas turbines are disclosed. The approach utilizes high speed infrared imagery provided by an online monitor system using a focal plan array (FPA) for near-infrared monitoring during engine runtime up to base load. The one waveband method for temperature estimation is assumed as starting point. A lower surface emissivity and higher surface reflectance of thermal barrier coating (TBC) in near-infrared can cause systematic estimation errors. Methods using the one wave band method, with the purpose to reduce estimation errors for maximum temperatures are also disclosed. Theoretical results, data from numerical simulations, and real data from engine test are provided. A system for performing temperature estimation methods is also disclosed.

Claims10

Dependent claims

A method for temperature estimation of a surface of a body, comprising:

receiving an image of the body with a sensor;
providing the image to a processor to remove sensor specific non-uniformities to create a corrected image having a plurality of pixels from the image, each of the plurality of pixels having a pixel value;
transforming the pixel value for each of the plurality of pixels in the corrected image into an estimated temperature value by using a polynomial function of pixel values;
correcting the estimated temperature value for each of the plurality of pixels using a model expressed by:
E
=
∫
λ
=
λ
1
λ
=
λ
2
⁢
S
⁡
(
λ
)
⁢
ɛ
⁡
(
λ
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⁢
B
⁡
(
T
,
λ
)
⁢
ⅆ
λ
+
∫
λ
=
λ
1
λ
=
λ
2
⁢
S
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(
λ
)
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(
1
-
ɛ
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(
λ
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⁢
g
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ɛ
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λ
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1
-
g
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B
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T
0
,
λ
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,
wherein E represents a radiation, λ represents a wavelength of radiation received by a sensor element of the sensor, S represents a spectral sensitivity, B represents a Planck law spectral radiance and g is a geometry factor;
and
displaying the estimated temperature value for each of the plurality of pixels.

99 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/872,758Filed 16 Oct 2007 · us provisional application
Priority: 20 Oct 2006
Published: US 2008/0095212 A124 Apr 2008
Granted: 15 Feb 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

G01J 5/0003
Radiation pyrometry, e.g. infrared or optical thermometry: for sensing the radiant heat transfer of samples, e.g. emittance meter
G01J 5/0022
Radiation pyrometry, e.g. infrared or optical thermometry: for sensing the radiation of moving bodies
G01J 5/0088
Radiation pyrometry, e.g. infrared or optical thermometry: in turbines
G01J 5/06
Constructional details: arrangements for eliminating effects of disturbing radiation; Arrangements for compensating changes in sensitivity