PHASED ARRAY ULTRASONIC INSPECTION SYSTEM FOR TURBINE AND GENERATOR ROTOR BORE

• US 20120055255A1
• Filed: 09/02/2010
• Published: 03/08/2012
• Est. Priority Date: 09/02/2010
• Status: Active Grant

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Energy Incorporated (Siemens AG)
• Inventors: Metala, Michael J., Abbasi, Waheed A.
• Granted Patent: US 8,438,929 B2
• Time in Patent Office: Days
• US Class Current: 73/660
• CPC Class Codes: G01M 13/00 Testing of machine parts
• CPC Class Codes: G01N 2291/0289 Internal structure, e.g. defects, grain size, texture
• CPC Class Codes: G01N 2291/106 one or more transducer arrays
• CPC Class Codes: G01N 2291/2636 cylindrical from inside
• CPC Class Codes: G01N 2291/2693 Rotor or turbine parts
• CPC Class Codes: G01N 29/07 by measuring propagation velocity or propagation time of acoustic waves
• CPC Class Codes: G01N 29/223 Supports, positioning or alignment in fixed situation mounting transducers per se G10K11/004
• CPC Class Codes: G01N 29/2456 Focusing probes focusing arrangements G01N29/221
• CPC Class Codes: G01N 29/262 by electronic orientation or focusing, e.g. with phased arrays phased arrays per se G10K11/34

Abstract

A phased array ultrasonic testing system for examining discontinuities in turbine or generator rotor bores formed within turbine or generator rotors of a turbine or generator rotor assembly. The system includes a phased array ultrasonic transducer structured to be coupled to a surface of the rotor bore at a first location in order to emit an ultrasonic beam toward a second location of the rotor bore which is to be examined. The system further includes a control system with a computer and a controller for programming, emitting, and steering the ultrasonic beam via at least one, two-dimensional phased array transducer, thereby precisely and accurately inspecting the area of interest. Computer control of the beam permits the number of inspection locations and the number of different transducer wedges to be reduced providing for an efficient, timely inspection.

Claims

1. A phased array ultrasonic testing system for examining a rotor bore formed within a rotor of a turbine or generator rotor assembly, the rotor having an interior surface and an exterior surface, the interior surface serves as a surface of the rotor bore, the phased array ultrasonic testing system comprising:

a phased array ultrasonic transducer structured to be coupled to the surface of the rotor bore at a first location, the phased array ultrasonic transducer emits an ultrasonic beam from the first location toward a second location of the surface of the rotor bore; and

a control system adapted to define a plurality of focal laws of the ultrasonic beam, controls the emission of the ultrasonic beam from the phased array ultrasonic transducer and steers and focuses the ultrasonic beam to conduct a non-destructive examination of the rotor bore.

2. The phased array ultrasonic testing system of claim 1 wherein the control system comprises a computer and a controller;

and wherein the computer is structured to program the controller which is adapted to manipulate the phased array ultrasonic transducer in order to perform the non-destructive examination.

3. The phased array ultrasonic testing system of claim 1 wherein the phased array ultrasonic transducer comprises a two-dimensional phased array transducer having a plurality of elements;

wherein the two-dimensional phased array transducer is mounted in a stationary position on the surface of the rotor bore; and

wherein the control system is adapted to actuate the elements in order to steer the beam in a first direction and in a second direction.

4. The phased array ultrasonic testing system of claim 1 wherein the surface of the rotor bore is a curved surface.

5. The phased array ultrasonic testing system of claim 1 including a wedge disposed between the surface of the rotor bore and the phased array ultrasonic transducer, the wedge structured to couple the phased array ultrasonic transducer to the surface of the rotor bore and to focus the ultrasonic beam on a portion of the rotor bore being examined.

6. The phased array ultrasonic testing system of claim 1 wherein a plurality of phased array ultrasonic transducers are coupled to the surface of the rotor bore.

7. The phased array ultrasonic testing system of claim 1 wherein the phased array ultrasonic transducer comprises a plurality of elements.

8. A method of ultrasonically examining a rotor bore formed in a rotor of a turbine or generator rotor assembly, the method comprising:

coupling a phased array ultrasonic transducer at a first location on a surface of the rotor bore, emitting an ultrasonic beam from the phased array ultrasonic transducer at the first location toward a second location of the rotor bore which is to be examined, calculating a plurality of focal laws for the ultrasonic beam;

programming a control system in accordance with the focal laws to control the emission of the ultrasonic beam from the phased array ultrasonic transducer; and

steering and focusing the ultrasonic beam to a portion of the rotor bore to be examined.

9. The method of claim 8 further comprising collecting ultrasonic data from the rotor bore and analyzing the data to detect one or more discontinuities therein.

10. The method of claim 8 further comprising performing the ultrasonic examination of the rotor bore using an ultrasonic testing technique selected from the group consisting of pulse echo, pitch catch, electronic scanning, dynamic depth focusing, sectorial scanning, and a combination of thereof.

11. The method of claim 8 further comprising programming a controller of the control system using a computer, wherein the programming includes defining the focal laws for the ultrasonic beam.

12. The method of claim 8 further comprising the focal laws selected from the group consisting of beam angle, focal distance, beam width, focal point and combinations thereof.

13. The method of claim 8 further comprising the phased array ultrasonic transducer comprising a two-dimensional (2D) phased array transducer having a plurality of elements.

14. The method of claim 8 wherein the surface of the rotor bore is a curved surface.

15. The method of claim 8 wherein said method is employed to determine geometry of the rotor.

16. The method of claim 8 wherein non-phased array transducers are used to determine geometry of the rotor.