Flowmeter Insulation Deterioration Diagnosis

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Solution Overview

Problem

Existing flowmeters, such as electromagnetic and Coriolis-type mass flowmeters, face challenges in diagnosing insulation deterioration of the exciting coil without disrupting fluid flow, leading to potential measurement errors and increased maintenance costs due to the need to stop fluid flow for detector replacement or modification.

Innovation Solution

A flowmeter system that includes a detector with an exciting coil and electrodes, utilizing a converter with an exciting circuit, current detecting resistance, differential amplifier, and CPU to diagnose insulation deterioration by alternately applying positive and negative exciting currents and comparing the detected current values to a reference threshold, allowing for real-time diagnosis without significant configuration changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the detector is mounted on the pipe in which the fluid flows, then the flowmeter can measure flow quantity in real-time, but the detector cannot be easily exchanged or changed without stopping the fluid flow

Engineering Contradiction:
Improvereal-time flow measurementVSAvoiddetector exchange
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent applies preliminary action by performing insulation deterioration diagnosis before the detector fails completely. The diagnosis function continuously monitors the exciting coil's insulation state using inductance measurement, allowing maintenance to be scheduled proactively during convenient times rather than reacting to failures that require immediate detector replacement.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by continuously monitoring the inductance of the exciting coil and comparing it against reference values. The diagnosis function provides real-time feedback on the insulation state, enabling predictive maintenance and avoiding sudden failures that would disrupt fluid flow and require urgent detector exchange.

Inventive Principle:
Principle #23Feedback

2Ease of repair

If the flow of the fluid is stopped so as to exchange or change the detector, then the detector can be replaced, but a large opportunity loss occurs in the plant and factory

Engineering Contradiction:
Improvedetector replacementVSAvoidmaintenance downtime
Core Design Contradiction:
Ease of repairVSLoss of time

Solution Approach 1:

The patent performs preliminary diagnosis of the exciting coil's insulation state while the system is operating normally. By identifying deterioration trends early through continuous inductance monitoring, the system enables scheduled maintenance during convenient windows rather than emergency repairs requiring production shutdown.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The diagnosis function serves the system by automatically monitoring its own health status without requiring external intervention or production shutdown. The inductance measurement and comparison operations perform self-diagnosis continuously, eliminating the need for manual inspection or forced downtime for routine checks.

Inventive Principle:
Principle #25Self-service

3Reliability

If a dedicated signal line is provided for the insulation deterioration diagnosis, then the diagnosis function can operate independently, but the device complexity increases

Engineering Contradiction:
Improvediagnosis function independenceVSAvoidsignal line configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the existing signal line serve multiple functions: it carries both the measurement signal for flow quantity detection and the signal for insulation deterioration diagnosis. The diagnosis function reuses the same exciting coil and signal transmission path, eliminating the need for dedicated diagnosis signal lines and reducing overall device complexity.

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

Solution Approach 2:

The patent merges the diagnosis function with the existing measurement system by combining the inductance measurement operations with the flow measurement operations. Both functions use the same exciting coil, electrodes, and signal processing path, integrating diagnostic capability into the existing device architecture without adding separate dedicated components.

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 accurate insulation deterioration diagnosis of the exciting coil in real-time, preventing measurement errors and reducing maintenance downtime by allowing for continuous fluid flow during diagnosis, thus minimizing operational disruptions.

Implementation Method 1

The electromagnetic flowmeter detects an electromotive force generated by applying a magnetic field to the fluid (an electromotive force proportional to flow velocity)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The detecting electrodes detect the electromotive force generated in the fluid

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2966415B1Flowmeter, insulation deterioration diagnosis system, and insulation deterioration diagnosis method
Publication Date: 2022.05.11 YOKOGAWA ELECTRIC CORP
  • EP2966415B1 patent drawingFigure 1
  • EP2966415B1 patent drawingFigure 2
  • EP2966415B1 patent drawingFigure 3A~3B

AI summary

A flowmeter includes an exciter configured to excite fluid which is a measurement target, a state detector configured to detect a state of the fluid excited by the exciter, a driver configured to supply exciting current for driving the exciter, a first current detector that is disposed between the exciter and the driver, the first current detector being configured to detect the exciting current, and a processor configured to diagnose insulation deterioration of the exciter in accordance with a change of a detection result of the first current detector.