Two-Phase Flow Exciting Force Evaluation Using Integrated Vibration and Void Fraction Measurement

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Solution Overview

Problem

Existing methods for evaluating the exciting force of a two-phase flow on tube bodies in steam generators are cumbersome and require multiple pieces of equipment, making accurate and synchronized measurements of void fraction and vibration challenging, leading to a large and difficult-to-install device.

Innovation Solution

A two-phase flow exciting force evaluation method and device that measures void fraction and displacement or stress of a vibrating tube body using a single configuration, allowing for accurate evaluation of the exciting force by integrating void fraction and vibration measurements through electrodes and sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple independent equipment are arranged to measure void fraction and vibration separately, then measurement functions are complete, but device complexity increases and installation becomes troublesome

Engineering Contradiction:
Improvemeasurement completenessVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the void fraction measurement function and vibration measurement function into a single integrated device. The vibration pipe serves dual purposes: it vibrates in response to exciting forces while also functioning as the measurement object for void fraction. This merging eliminates the need for separate independent equipment, reducing device complexity while maintaining complete measurement capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The vibration pipe is designed with multi-functionality, serving both as the object to be vibrated by the two-phase flow and as the sensor for measuring void fraction. By making the measurement object itself serve multiple functions, the patent reduces the number of components needed and simplifies the overall device configuration.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If multiple equipment are installed in different positions, then measurement coverage is adequate, but synchronization of measurement results becomes difficult and time consuming

Engineering Contradiction:
Improvemeasurement coverageVSAvoidsynchronization time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

By merging the void fraction measurement and vibration measurement into a single integrated device located at one position, the patent eliminates the synchronization problems associated with multiple distributed sensors. The co-located measurements are naturally synchronized, eliminating the time delays and coordination complexity required when using multiple independent equipment at different positions.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If independent measurement equipment are used for void fraction and vibration, then measurement accuracy is maintained, but installation becomes troublesome and device size increases

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidinstallation ease
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent merges multiple measurement functions into a single device that can be installed at one location, dramatically improving installation ease. The integrated design requires only a single installation position rather than multiple separate installations, reducing installation complexity while preserving measurement accuracy through the use of appropriate sensors for each measurement type.

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables easy and accurate evaluation of the exciting force acting on tube bodies with a simplified device configuration, reducing installation complexity and improving measurement accuracy by correlating void fraction and vibration data.

Implementation Method 1

a vibration pipe 3A to be vibrated, and a voltage generating section that generates voltage based on vibration of the vibration pipe 3A

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

arranging electrodes respectively on the inner surface and in the center portion of a flow path along which the two-phase flow travels, and measuring voltages occurring between these electrodes

Methodology Applied
Scientific EffectElectrical potential measurement: Electric Field

Data Source

PatentEP2434498B1Two-phase flow exciting force evaluation method and two-phase flow exciting force evaluation device
Publication Date: 2016.03.30 MITSUBISHI HEAVY IND LTD
  • EP2434498B1 patent drawingFigure 1
  • EP2434498B1 patent drawingFigure 2
  • EP2434498B1 patent drawingFigure 3(a)~3(b)

AI summary

In a two-phase flow exciting force evaluation method of the present invention, the surface of one of a plurality of tube bodies (3) is at least partially formed from a conductive material, displacement or stress of the tube body (3) is measured in a state of being vibrated by a shaking device (4), and a void fraction of a two-phase flow (F) flowing in the vicinity of the tube body (3) is measured based on the potential difference between an electric potential at a predetermined position on the surface of the tube body (3), and a reference electric potential.