SF6 Gas Sensor Bellows Mechanism for Leak Detection

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Solution Overview

Problem

Current gas monitoring technologies for sulfur hexafluoride (SF6) in high voltage electric switchgear lack the sensitivity and cost-effectiveness needed to achieve significant reductions in emissions, with existing methods being either expensive or error-prone, and fail to provide real-time, network-manageable solutions for detecting and mitigating leaks.

Innovation Solution

A highly integrated gas sensor system combining mechanical, electronic, and algorithmic components with network connectivity, utilizing a mechanical bellows for pressure sensing and microcontroller-based data processing to accurately measure and communicate SF6 mass changes, enabling early leak detection and mitigation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If expensive equipment like IR cameras is used for SF6 leakage detection, then measurement precision is improved, but device complexity and cost increase significantly

Engineering Contradiction:
ImproveSF6 leakage detection sensitivityVSAvoidequipment complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex optical detection systems (IR cameras) with a simpler mechanical pressure sensing system using a bellows element that directly converts pressure changes into measurable displacement, eliminating the need for expensive optical components while maintaining detection capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a bellows element as an intermediary mechanical component that mediates between the gas pressure and the measurement system, amplifying small pressure changes into larger mechanical displacements that can be easily detected by simple transducers

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If indirect mass-balance accounting methods are used for emissions estimation, then device complexity is reduced, but measurement precision deteriorates due to errors

Engineering Contradiction:
Improvemonitoring system complexityVSAvoidemissions estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The sensor system performs self-calibration and automatic compensation for temperature and pressure variations through integrated sensing elements, eliminating the need for complex external calibration procedures and manual mass-balance calculations while maintaining high measurement accuracy

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent incorporates feedback mechanisms where the sensor continuously monitors its own operating conditions and automatically adjusts measurements to compensate for environmental variations, ensuring sustained measurement precision without complex external intervention

Inventive Principle:
Principle #23Feedback

3Reliability

If traditional gas density relays with bi-metallic compensation are used, then temperature compensation is achieved, but device complexity and response time increase

Engineering Contradiction:
Improvetemperature compensation accuracyVSAvoidrelay mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex bi-metallic relay mechanisms with electronic temperature sensing and digital compensation algorithms, converting mechanical temperature compensation into an electronic process that is faster and more precise while reducing mechanical complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the compensation mechanism from mechanical (bi-metallic expansion) to electronic (digital signal processing), allowing for more precise and adjustable temperature compensation while reducing the physical complexity of the device

Inventive Principle:
Principle #35Parameter changes

4Productivity

If distributed sensor technology is deployed worldwide for SF6 monitoring, then productivity in emissions mitigation is improved, but loss of substance increases due to potential installation complexity

Engineering Contradiction:
Improveemissions mitigation efficiencyVSAvoidSF6 loss during installation
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The sensor system includes self-diagnostic and self-calibration capabilities that allow for easy installation and commissioning without requiring specialized handling procedures, reducing the risk of SF6 loss during installation while enabling widespread deployment

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent incorporates pre-calibration and pre-configuration of sensors during manufacturing, allowing for rapid deployment with minimal on-site adjustment and reducing installation time and potential for SF6 loss during the installation process

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2880413B1Network manageable advanced gas sensor apparatus and method
Publication Date: 2019.10.30 SOLON MANUFACTURING CO
  • EP2880413B1 patent drawingFigure 1
  • EP2880413B1 patent drawingFigure 2
  • EP2880413B1 patent drawingFigure 3

AI summary

Mechanical, electronic, algorithmic, and computer network facets are combined to create a highly integrated advanced gas sensor system. The sensor system, utilized with gas insulated high voltage switchgear products, deployed by electric utility end users in replacement and expansion cycles, function to detect and mitigate atmospheric pollution caused by leaking SF6. As its associated gas insulated tank is charged with 10 to 350 lbs. of SF6, each gas sensor monitors its local cache of gas, accurately sensing and computing fractional percentage losses (emissions) and gains (maintenance replacement) in SF6 mass, storing data in onboard data logs, and communicating data when triggered by detection events or in response to remote requests over a hierarchical communications network, a process that continues without labor until a fractional leak is automatically detected and reported creating the opportunity for early leak mitigation.