Optical based system and method for monitoring turbine engine blade deflection

Patent metadata

Field	Value
Publication number	US-2016010496-A1
Application number	US-201414326494-A
Country	US
Kind code	A1
Filing date	Jul 9, 2014
Priority date	Jul 9, 2014
Publication date	Jan 14, 2016
Grant date	—

Abstract

An optical based system and method for monitoring turbine engine blade deflection during engine operation. An optical camera is coupled the exterior of an engine inspection port, so that its field of view captures images of a rotating turbine blade, such as the blade tip. The camera's image capture or sampling rate matches blade rotation speed at the same rotational position, so that successive temporal images of one or more blades show relative movement of the blade tip within the image field of view. The captured successive images are directed to a blade deflection monitoring system (BDMS) controller. The controller correlates change in a blade's captured image position within the camera field of view between successive temporal images with blade deflection. The BDMS alarms or trips engine operation if the monitored blade deflection falls outside permissible operation parameters.

First claim

What is claimed is:

1 . A method for monitoring turbine blade deflection during turbine engine operation, comprising:
establishing an optical camera field of view within an operating turbine engine that captures optical images of at least a portion of a turbine blade at a rotational position; capturing a first image of the turbine blade portion in the field of view at the rotational position; capturing a second image of the turbine blade portion in the field of view at the same rotational position at a later time; determining change in relative position of the turbine blade portion within the field of view between the first and second images; and correlating the determined change in the turbine blade portion relative position with the turbine blade deflection.

2 . The method of claim 1 , further comprising defining a permissible range of turbine blade portion relative positions in the field of view and alarming if the blade portion relative position is outside the permissible range.

3 . The method of claim 1 , further comprising capturing successive images of the turbine blade portion in the field of view at the same rotational position at a sampling rate.

4 . The method of claim 3 , further comprising correlating rate of change of relative position of the turbine blade portion within the field of view between the first and plural successive temporal images with rate of change of blade deflection and alarming if said rate of change exceeds an established permissible range.

5 . The method of claim 3 , the blade rotational position determined with a turbine shaft position/speed sensor.

6 . The method of claim 1 , the blade rotational position determined with a turbine shaft position/speed sensor.

7 . The method of claim 1 , further comprising:
capturing first and second images of plural individual blade portions; for each respective individual blade portion, determining its change in relative position within the field of view between its respective first and second images; and for each respective individual blade portion, correlating the determined change in the turbine blade portion relative position with the turbine blade deflection.

8 . An operating turbine engine blade deflection monitoring system, comprising:
an optical camera having a field of view, the camera adapted for coupling to an operating turbine engine, so that its field of view captures optical images of at least a portion of a turbine blade at a rotational position within the turbine engine; the camera capable of capturing a first image of the turbine blade portion in the field of view at the rotational position; the capable of capturing a second image of the turbine blade portion in the field of view at the same rotational position at a later time; a blade deflection monitoring system controller, coupled to the camera, for receiving the first and second images and determining change in relative position of the turbine blade portion within the field of view between the first and second images; and the controller correlating the determined change in the turbine blade portion relative position with the turbine blade deflection.

9 . The system of claim 8 , the camera comprising an optical tube adapted for insertion into and coupling to an inspection port of a turbine engine, so that the field of view through the optical tube generates images of at least a portion of a turbine blade at a rotational position within the turbine engine, with image capture components of the camera remaining outside the engine.

10 . The system of claim 9 , the optical tube capable of continuous image generation during turbine engine operation.

11 . The system of claim 8 , the controller defining a permissible range of turbine blade portion relative positions in the field of view and alarming if the blade portion relative position is outside the permissible range.

12 . The system of claim 8 , the controller capturing successive images of the turbine blade portion in the field of view at the same rotational position at a sampling rate.

13 . The system of claim 12 , the controller correlating rate of change of relative position of the turbine blade portion within the field of view between the first and plural successive temporal images with rate of change of blade deflection and alarming if said rate of change exceeds an established permissible range.

14 . The system of claim 12 , further comprising a turbine shaft position/speed sensor coupled to the controller, for determining blade rotational position.

15 . The system of claim 8 , further comprising:
the camera capturing first and second images of plural individual blade portions; the controller determining, for each respective individual blade portion, blade portion change in relative position within the field of view between its respective first and second images; and the controller correlating, for each respective individual blade portion, determined change in relative position with the turbine blade deflection.

16 . The system of claim 8 , the blade portion comprising a blade tip.

17 . The system of claim 8 , the camera capturing optical images in the infra-red or visible light spectral range.

18 . The system of claim 17 , the camera capable of capturing images at a sample rate equal to or multiples of blade rotational speed.

19 . A turbine engine, comprising:
a housing defining an inspection port; a rotating shaft in the housing, having an array of turbine blades; and a turbine engine blade deflection monitoring system, including:
an optical camera having a an optical tube, coupled to the inspection port, so that a field of view through the optical tube generates images of at least a portion of a turbine blade at a rotational position within the turbine engine housing, with image capture components of the camera remaining outside the engine;
the camera capable of capturing a first image of the turbine blade portion in the field of view at the rotational position;
the capable of capturing a second image of the turbine blade portion in the field of view at the same rotational position at a later time;
a blade deflection monitoring system controller, coupled to the camera, for receiving the first and second images and determining change in relative position of the turbine blade portion within the field of view between the first and second images; and
the controller correlating the determined change in the turbine blade portion relative position with the turbine blade deflection.

20 . The engine of claim 19 , further comprising:
the camera capturing first and second images of plural individual blade portions; the controller determining, for each respective individual blade portion, blade portion change in relative position within the field of view between its respective first and second images; and the controller correlating, for each respective individual blade portion, determined change in relative position with the turbine blade deflection.

Assignees

• Siemens Energy Inc

Inventors

• Hatcher Jr Clifford
• Nordlund Raymond S

Classifications

• F05D2240/304

  related to the trailing edge of a rotor blade · CPC title

• F01D21/003

  Arrangements for testing or measuring (for measuring vibrations G01H) · CPC title

• F01D21/06 Primary

  Shutting-down · CPC title

• F05D2270/8041

  Cameras · CPC title