Method of predicting wear on tubes of steam generator

Patent metadata

Field	Value
Publication number	US-9845950-B2
Application number	US-201615215002-A
Country	US
Kind code	B2
Filing date	Jul 20, 2016
Priority date	Jul 20, 2015
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

A method predicts an amount of wear that is expected to occur on the tubes of a steam generator as a result of vibration against another structure within the steam generator. The method includes determining a volumetric amount of material that has been worn from a location on a tube over a duration of time and employing that volume as a function of time to determine the volume of material of the tube wall that is predicted to be worn from the tube or another tube at a future time. The volumetric-based analysis enables more accurately prediction of the wear depth at a future time. This enables the plugging of only those tubes that are determined from a volumetric analysis to be in risk of breach at the future time, thus slowing the rate at which tubes of a steam generator will be plugged.

First claim

What is claimed is:

1. A method of predicting an amount of wear that is expected to occur on one or more tubes from among a plurality of tubes of a steam generator as a result of vibration against another structure of the steam generator, the method comprising:
determining a durational volumetric amount of material that has been worn from a given location on at least one tube from among the plurality of tubes over a duration of time;
determining a current wear state of a particular tube from among the plurality of tubes, the current wear state including a current volumetric amount of material that has been worn from a particular location on the particular tube compared with a new condition;
determining a predicted wear state at the particular location, the predicted wear state including a future volumetric amount of material that is predicted to be worn from the particular location at a future time, the future volumetric amount being based at least in part upon the current volumetric amount and the durational volumetric amount;
determining based at least in part upon the predicted wear state a predicted wear depth that is predicted to exist at the particular location at the future time; and
plugging the particular tube responsive to the predicted wear depth meeting a predetermined threshold.

2. The method of claim 1 , further comprising:
performing the determining of the current wear state at a current time prior to the future time; and
performing the plugging at a time subsequent to the current time but prior to the future time.

3. The method of claim 1 , further comprising employing the particular tube as the at least one tube.

4. The method of claim 1 , further comprising:
performing the determining of the current wear state at a current time, the future time being a period of time subsequent to the current time; and
calculating the future volumetric amount by adding together the current volumetric amount and a proportional portion of the durational volumetric amount that corresponds with the ratio of the period of time to the duration of time.

5. The method of claim 1 , further comprising:
performing on the steam generator an inspection operation on fewer than all of the tubes of the plurality of tubes wherein a given tube other than the particular tube and the at least one tube is uninspected during the inspection operation;
predicting a predicted wear condition on the given tube that includes a predicted volumetric amount of material that is predicted to be worn from a given location on the given tube at the future time, the predicted volumetric amount being based at least in part upon the current volumetric amount and the durational volumetric amount;
determining based at least in part upon the predicted wear condition a calculated wear depth that is predicted to exist at the given location at the future time; and
operating the steam generator without plugging the given tube responsive to the calculated wear depth not meeting a predetermined threshold.

6. The method of claim 1 , further comprising:
performing the determining of the current wear state at a current time, the future time being a period of time subsequent to the current time; and
calculating the predicted volumetric amount by adding together the current volumetric amount and a proportional portion of the durational volumetric amount that corresponds with the ratio of the period of time to the duration of time.

Assignees

• Westinghouse Electric Co Llc

Inventors

• Cullen William K

Classifications

• F28F11/02

  using obturating elements, e.g. washers, inserted and operated independently of each other (F28F11/06 takes precedence) · CPC title

• G06N5/04

  Inference or reasoning models · CPC title

• F28F2200/00

  Prediction; Simulation; Testing · CPC title

• G01B7/10

  using magnetic means, e.g. by measuring change of reluctance · CPC title

• F22B37/42

  Applications, arrangements or dispositions of alarm or automatic safety devices (for feed-water heaters F22D1/14 {; emergency feed-water supply F22D11/003}) · CPC title