VIBRATION MONITORING APPARATUS AND VIBRATION MONITORING METHOD

• US 20110154900A1
• Filed: 09/12/2008
• Published: 06/30/2011
• Est. Priority Date: 09/13/2007
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Hagiwara, Tsuyoshi, Warashina, Masahiko, Sato, Michio, Sato, Mieko, Watanabe, Masanobu, Kitajima, Yasumi
• Granted Patent: US 8,701,493 B2
• Time in Patent Office: Days
• US Class Current: 73/579
• CPC Class Codes: G01H 17/00 Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves, not provided for in the preceding groups see provisionally also G01H1/00
• CPC Class Codes: G01H 9/008 by using ultrasonic waves measuring position using ultrasonic waves G01S15/02
• CPC Class Codes: G01N 2291/045 External reflections, e.g. on reflectors
• CPC Class Codes: G01N 2291/2693 Rotor or turbine parts
• CPC Class Codes: G01N 29/11 by measuring attenuation of acoustic waves
• CPC Class Codes: G01N 29/4427 with stored values, e.g. threshold values
• CPC Class Codes: G01N 29/48 by amplitude comparison
• CPC Class Codes: G21C 15/25 using jet pumps
• CPC Class Codes: G21C 17/00 Monitoring; Testing measuring in general G01; Maintaining
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors

Abstract

The present invention provides a vibration monitoring apparatus that monitors vibration of a jet pump disposed in a reactor pressure vessel using ultrasonic wave, including: an ultrasonic sensor that is attached to an outside the reactor pressure vessel, and transmits and receives ultrasonic wave; a reflector that is mounted on a surface of a riser pipe of the jet pump, and includes a planar reflecting surface that can reflect ultrasonic wave; and a signal processing unit that performs signal processing of the ultrasonic wave transmitted by the ultrasonic sensor, reflected by the reflecting surface of the reflector, and received by the ultrasonic sensor, and measures a vibration amplitude of the riser pipe and calculates a vibration waveform.

Claims

1. A vibration monitoring apparatus that monitors vibration of an object to be monitored disposed in a vessel using ultrasonic wave, comprising:

an ultrasonic sensor that is attached to an outside the vessel, and transmits and receives the ultrasonic wave;

a reflector that is mounted on a surface of the object to be monitored, and includes a planar reflecting surface that reflects ultrasonic wave; and

a signal processing unit that performs signal processing of the ultrasonic wave transmitted by the ultrasonic sensor, reflected by the reflecting surface of the reflector, and received by the ultrasonic sensor, and measures vibration displacement of the object to be monitored.

2. The vibration monitoring apparatus according to claim 1, wherein the ultrasonic sensor is provided in each of a direction perpendicular to a longitudinal direction of the object to be monitored and a direction at a predetermined angle from the direction toward the longitudinal direction, and reflectors are mounted on the object to be monitored correspondingly to the ultrasonic sensors.

3. The vibration monitoring apparatus according to claim 1, wherein the signal processing unit detects abnormal vibration when an amplitude level as the measured vibration displacement of the object to be monitored exceeds a normal amplitude level of the object to be monitored.

4. The vibration monitoring apparatus according to claim 1, wherein the reflector is a corner reflector including planes perpendicular to each other as reflecting surfaces.

5. The vibration monitoring apparatus according to claim 1, wherein the reflector is provided in a region with a relatively large amplitude in the normal vibration mode of the object to be monitored.

6. The vibration monitoring apparatus according to claim 1, wherein a plurality of reflectors are arranged along the longitudinal direction of the object to be monitored and a plurality of ultrasonic sensors are attached to an outside the vessel correspondingly to the reflectors.

7. The vibration monitoring apparatus according to claim 1, wherein the ultrasonic sensor is attached to a region where the ultrasonic sensor is allowed to receive ultrasonic wave reflected by the reflector mounted on the object to be monitored in a vibration mode of abnormal vibration other than normal vibration of the object to be monitored.

8. The vibration monitoring apparatus according to claim 1, wherein the vessel is a reactor pressure vessel, and the object to be monitored is a component of a jet pump disposed in the reactor pressure vessel.

9. The vibration monitoring apparatus according to claim 1, wherein the vessel is a reactor pressure vessel, the object to be monitored is a wedge of the jet pump, and the ultrasonic sensor is attached to an outside of a region where, due to movement of the wedge, the ultrasonic sensor is allowed to receive ultrasonic wave reflected by the reflector mounted on the wedge.

10. A vibration monitoring apparatus that monitors a position change based on wear and degradation due to vibration of an object to be monitored disposed in a vessel using ultrasonic wave, comprising:

a plurality of ultrasonic sensors that are attached to an outside the vessel along a longitudinal direction of the object to be monitored, and transmit and receive ultrasonic wave;

a signal processing unit that performs signal processing of the ultrasonic wave transmitted by the ultrasonic sensors, reflected by the object to be monitored, and received by the ultrasonic sensors, and measures a position of the object to be monitored; and

a calculation unit that accumulates a time series change of the position of the object to be monitored, compares the accumulated time series change of the position and position change data with development of wear of the object to be monitored, and predicts timing when the object to be monitored reaches an acceptable limit value of wear amount.

11. The vibration monitoring apparatus according to claim 10, wherein the vessel is a reactor pressure vessel, and the object to be monitored is a wedge of a jet pump disposed in the reactor pressure vessel.

12. A vibration monitoring apparatus that monitors vibration of an object to be monitored disposed in a vessel using ultrasonic wave, comprising:

a plurality of ultrasonic sensors that are attached to an outside the vessel along a longitudinal direction the object to be monitored, and transmit and receive ultrasonic wave;

a signal processing unit that performs signal processing of the ultrasonic wave transmitted by the ultrasonic sensors, reflected by the object to be monitored, and received by the ultrasonic sensor, and measures a vibration amplitude of the object to be monitored;

a calculation unit that accumulates a time series change of the vibration amplitude of the object to be monitored; and

a frequency analyzer that calculates a vibration frequency at which the vibration amplitude of the object to be monitored is maximum and the maximum amplitude from the time series change of the vibration amplitude of the object to be monitored,

wherein the calculation unit or the frequency analyzer accumulates the time series change of the vibration frequency at which the vibration amplitude of the object to be monitored is at the maximum, and

the calculation unit outputs a warning signal to a warning unit when the accumulated time series change of the vibration frequency reaches an acceptable limit value of a preliminarily calculated frequency change.

13. The vibration monitoring apparatus according to claim 12, wherein the vessel is a reactor pressure vessel, and the object to be monitored is a wedge of a jet pump disposed in the reactor pressure vessel.

14. The vibration monitoring apparatus according to claim 12, wherein the calculation unit samples the time series change of the vibration frequency at which the vibration amplitude is maximum accumulated in the calculation unit or the frequency analyzer at regular time intervals, calculates a predicted frequency curve from time-series data of similar vibration frequencies sampled before, predicts a value of the vibration frequency at which the vibration amplitude is maximum at the next time interval from the sampled time series change of the vibration frequency and the predicted frequency curve, and outputs a warning signal to a warning unit when the predicted value reaches an acceptable value of a preliminarily calculated frequency change.

16. The vibration monitoring apparatus according to claim 12, wherein the vessel is a reactor pressure vessel, and the object to be monitored is a wedge of a jet pump disposed in the reactor pressure vessel.

15. A vibration monitoring apparatus that monitors vibration of an object to be monitored disposed in a vessel using ultrasonic wave, comprising:

a plurality of ultrasonic sensors that are attached to an outside the vessel along a longitudinal direction the object to be monitored, and transmit and receive ultrasonic wave;

a signal processing unit that performs signal processing of the ultrasonic wave transmitted by the ultrasonic sensors, reflected by the object to be monitored, and received by the ultrasonic sensor, and measures a vibration amplitude of the object to be monitored;

a calculation unit that accumulates a time series change of the vibration amplitude of the object to be monitored; and

a frequency analyzer that calculates a vibration frequency at which the vibration amplitude of the object to be monitored is maximum and the maximum amplitude from the time series change of the vibration amplitude of the object to be monitored,

wherein the calculation unit or the frequency analyzer accumulates the time series change of the maximum value of the vibration amplitude of the object to be monitored, and

the calculation unit outputs a warning signal to a warning unit when the accumulated time series change of the maximum value of the vibration amplitude reaches an upper limit value of an acceptable range of a preliminarily calculated maximum value of the vibration amplitude.

17. A vibration monitoring apparatus that monitors vibration of an object to be monitored disposed in a vessel using ultrasonic wave, comprising:

a plurality of ultrasonic sensors that are attached to an outside the vessel along a longitudinal direction the object to be monitored, and transmit and receive ultrasonic wave;

a signal processing unit that performs signal processing of the ultrasonic wave transmitted by the ultrasonic sensors, reflected by the object to be monitored, and received by the ultrasonic sensor, and measures a vibration amplitude of the object to be monitored;

a calculation unit that accumulates a time series change of the vibration amplitude of the object to be monitored; and

a frequency analyzer that calculates a vibration frequency at which the vibration amplitude of the object to be monitored is maximum and the maximum amplitude from the time series change of the vibration amplitude of the object to be monitored,

wherein the calculation unit or the frequency analyzer accumulates the time series change of the maximum value of the vibration amplitude of the object to be monitored, and

the calculation unit outputs a warning signal to a warning unit when the accumulated time series change of the maximum value of the vibration amplitude reaches an upper limit value of an acceptable range of a preliminarily calculated maximum value of the vibration amplitude.

18. The vibration monitoring apparatus according to claim 17, wherein the calculation unit samples the time series change of the maximum value of the vibration amplitude accumulated in the calculation unit or the frequency analyzer at regular time intervals, calculates a predicted amplitude curve from time-series data of similar maximum values of the vibration amplitude sampled before, predicts a maximum value of the vibration amplitude at the next time interval from the sampled time series change of the maximum value of the vibration amplitude and the predicted amplitude curve, and outputs a warning signal to a warning unit when the predicted value reaches an upper limit value of an acceptable range of a preliminarily calculated maximum vibration amplitude.

19. The vibration monitoring apparatus according to claim 17, wherein the vessel is a reactor pressure vessel, and the object to be monitored is a wedge of a jet pump disposed in the reactor pressure vessel.

20. A vibration monitoring method for monitoring vibration of an object to be monitored disposed in a vessel using ultrasonic wave, comprising the steps of:

reflecting ultrasonic wave from a ultrasonic sensor attached to an outside the vessel by a planar reflecting surface of a reflector mounted on a surface of the object to be monitored, and then receiving the ultrasonic wave by the ultrasonic sensor; and

performing signal processing of the ultrasonic wave received by the ultrasonic sensor and measuring vibration displacement of the object to be monitored.

21. A vibration monitoring method for monitoring a position change based on wear and degradation due to vibration of an object to be monitored disposed in a vessel using ultrasonic wave, comprising the steps of:

reflecting ultrasonic wave from a plurality of ultrasonic sensors attached to an outside the vessel along a longitudinal direction of the object to be monitored by the object to be monitored, and then receiving the ultrasonic wave by the ultrasonic sensors;

performing signal processing of the ultrasonic wave received by the ultrasonic sensors and measuring a position of the object to be monitored; and

comparing a time series change of the position of the object to be monitored and position change data with development of wear of the object to be monitored, and predicting timing when the object to be monitored reaches an acceptable wear amount.

22. A vibration monitoring method for monitoring vibration of an object to be monitored disposed in a vessel using ultrasonic wave, comprising the steps of:

reflecting ultrasonic wave from a plurality of ultrasonic sensors attached to an outside the vessel along a longitudinal direction of the object to be monitored by the object to be monitored, and then receiving the ultrasonic wave by the a ultrasonic sensors;

performing signal processing of the ultrasonic wave received by the ultrasonic sensors and measuring a vibration amplitude of the object to be monitored;

calculating a vibration frequency at which the vibration amplitude of the object to be monitored is maximum and the maximum amplitude from the time series change of the vibration amplitude of the object to be monitored; and

issuing a warning when the time series change of the vibration frequency at which the vibration amplitude of the object to be monitored is maximum reaches acceptable limit value of a preliminarily calculated frequency change.

23. A vibration monitoring method for monitoring vibration of an object to be monitored disposed in a vessel using ultrasonic wave, comprising the steps of:

reflecting ultrasonic wave from a plurality of ultrasonic sensors attached to an outside the vessel along a longitudinal direction of the object to be monitored by the object to be monitored, and then receiving the ultrasonic wave by the a ultrasonic sensors;

performing signal processing of the ultrasonic wave received by the ultrasonic sensors and measuring a vibration amplitude of the object to be monitored;

calculating a vibration frequency at which the vibration amplitude of the object to be monitored is maximum and the maximum amplitude from the time series change of the vibration amplitude of the object to be monitored; and

issuing a warning when the time series change of a maximum value of the vibration amplitude of the object to be monitored reaches an upper limit value of an acceptable range of a preliminarily calculated maximum value of the vibration amplitude.