Liquid Analyzer System for Fault Gas Concentration Analysis

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Solution Overview

Problem

Existing methods for analyzing fault gas concentrations in liquids face challenges due to the interference of disturbing gases, which have stronger temperature-dependent solubility than fault gases, affecting measurement accuracy in industrial applications like transformer oil monitoring.

Innovation Solution

A liquid analyzer system that measures fault gas concentrations at multiple temperatures, determines the disturbing gas contribution, and compensates for its effects, using NDIR absorption or photoacoustic spectroscopy, with a cold trap for filtering and a controller for data processing, to improve measurement accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If gas concentration measurement is performed in transformer oil, then fault gas analysis can be conducted for condition monitoring, but disturbing gases with higher concentrations and stronger temperature-dependent solubility interfere with measurement accuracy

Engineering Contradiction:
Improvefault gas analysis reliabilityVSAvoidfault gas concentration measurement precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by measuring gas concentrations at multiple temperatures and using the temperature-dependent solubility differences between fault gases and disturbing gases to separate and compensate for interfering gas contributions, thereby improving measurement precision while maintaining analysis reliability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback by using the measured concentration data from multiple temperatures to calculate and subtract the disturbing gas contributions from the total measured signal, providing corrected fault gas concentrations that improve both precision and reliability

Inventive Principle:
Principle #23Feedback

2Measurement precision

If thermal conditioning is applied to eliminate temperature variations, then measurement stability is improved, but additional equipment complexity and calibration requirements are introduced

Engineering Contradiction:
Improvemeasurement stabilityVSAvoidthermal conditioning system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies partial action by not requiring complete thermal equilibrium or elimination of temperature variations, but instead using the actual temperature-dependent solubility variations to enable gas separation through multi-temperature measurements, reducing the need for complex thermal conditioning equipment

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent converts the harmful effect of temperature-dependent solubility variations into a beneficial separation mechanism, where the different temperature dependencies of fault gases and disturbing gases enable selective compensation and improved measurement precision without requiring complex thermal control systems

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

This approach significantly reduces the impact of disturbing gases on fault gas analysis, enhancing the accuracy of condition monitoring in industrial devices by accounting for temperature-dependent solubility differences and allowing for continuous, reliable fault detection.

Implementation Method 1

using NDIR absorption or photoacoustic spectroscopy

Methodology Applied
Scientific EffectNDIR absorption: Absorption (EM radiation)

Implementation Method 2

using NDIR absorption or photoacoustic spectroscopy

Methodology Applied
Scientific EffectPhotoacoustic spectroscopy: Photoacoustic Effect

Implementation Method 3

with a cold trap for filtering

Methodology Applied
Scientific EffectCold trap filtering: Condensation

Data Source

PatentEP3469355B1Analyzing fault gas concentration in liquid
Publication Date: 2022.12.28 VAISALA
  • EP3469355B1 patent drawingFigure 1
  • EP3469355B1 patent drawingFigure 2
  • EP3469355B1 patent drawingFigure 3

AI summary

According to an example aspect of the present invention, there is provided analyzing fault gas concentrations in a liquid. Concentration of at least one dissolved fault gas in the liquid is measured at least at two temperatures. Disturbing gas contribution is determined in at least one temperature on the basis of the fault gas concentration measurements. Fault gas concentrations are analyzed by compensating fault gas concentrations on the basis of the determined disturbing gas contribution.