Single Electrode Combustion Control via Plasma Signal Correlation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing combustion control methods for fuel gas burners face limitations in maintaining optimal air/fuel ratios across varying power levels and gas types, leading to unreliable results and electrode wear issues, especially in modulating burners.

Innovation Solution

A method using a single electrode to apply and measure electrical signals in the combustion plasma, correlating power and air ratios through discrete Fourier transform and regression analysis to ensure accurate and repeatable combustion control across different conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple flame sensors and frequency spectrum analysis are used to monitor combustion, then combustion control capability is improved, but device complexity and reliability deteriorate due to electrode wear and ageing

Engineering Contradiction:
Improvecombustion control capabilityVSAvoidelectrode reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent extracts the essential combustion monitoring function from complex multi-sensor systems and frequency spectrum analysis, retaining only the core capability of measuring combustion parameters through a single electrode. This simplification eliminates the reliability issues associated with multiple sensors and complex processing while maintaining effective combustion control.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a single electrode that can be easily replaced rather than investing in multiple durable sensors. This approach accepts the limited lifespan of a single electrode but eliminates the complexity and reliability problems of maintaining multiple sensors, effectively treating the electrode as a consumable component.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Difficulty of detecting and measuring

If frequency spectrum analysis is applied to combustion signals, then combustion parameter measurement is improved, but measurement precision deteriorates due to unreliable frequency spectrum results

Engineering Contradiction:
Improvecombustion parameter detectionVSAvoidcombustion parameter measurement accuracy
Core Design Contradiction:
Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent replaces complex frequency spectrum analysis with a simpler direct measurement approach using a single electrode to detect combustion parameters. This substitution eliminates the inaccuracies inherent in frequency spectrum methods while maintaining the ability to detect and measure combustion characteristics effectively.

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

3Adaptability or versatility

If modulating burners operate across wide power ranges, then adaptability is improved, but combustion control reliability deteriorates due to varying optimal air/gas ratios

Engineering Contradiction:
Improvepower range adaptabilityVSAvoidcombustion control reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements a dynamic combustion control system that automatically adjusts air/gas ratios in real-time according to the actual operating conditions and power level. This dynamic adaptation allows the modulating burner to maintain reliable combustion control across the entire power range without requiring manual intervention or complex pre-programmed control curves.

Inventive Principle:
Principle #15Dynamics

4Manufacturing precision

If multiple experimental conditions are tested to establish control curves, then manufacturing precision is improved, but loss of time increases due to extensive testing requirements

Engineering Contradiction:
Improvecontrol curve accuracyVSAvoidinstallation and testing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent enables the combustion control system to self-adjust and self-calibrate during operation rather than requiring extensive pre-establishment of control curves through multiple experimental conditions. The system automatically learns optimal air/gas ratios during normal operation, eliminating the need for time-consuming installation testing while maintaining high precision control.

Inventive Principle:
Principle #25Self-service

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 provides reliable and efficient combustion control by accurately determining air/fuel ratios and thermal power, reducing electrode wear and simplifying installation and operation, while maintaining optimal combustion conditions across the burner's power range.

Implementation Method 1

A voltage signal is applied to an electrode in the combustion plasma of a burner and, following disconnection of the signal, a series of samplings of the resultant signal at the electrode is carried out

Methodology Applied
Scientific EffectPlasma: Plasma

Data Source

PatentEP2901080B1Method for monitoring and controlling combustion in a fuel gas burner apparatus, and combustion control system operating in accordance with said method
Publication Date: 2021.05.19 SIT SPA
  • EP2901080B1 patent drawingFigure 1
  • EP2901080B1 patent drawingFigure 2
  • EP2901080B1 patent drawing

AI summary

A method is described for monitoring and controlling combustion in a burner (1) of a fuel gas apparatus, of the type comprising a sensor (8) with an electrode (El) located in or close to the flame and capable of being supplied by a voltage generator and also connected to an electronic circuit suitable for measuring the resultant potential at the electrode. The method comprises a first phase of acquiring and processing data from experimental conditions and a second phase of evaluating the desired combustion characteristic, under an actual operating condition of the burner. In the first phase a plurality of experimental combustion conditions for the burner (1) are preselected, applying to the burner in each of said conditions a power (PI, P2, Pn) and a further significant parameter of the combustion characteristics (Kl, K2, Km), under each of the experimental conditions applying an electrical voltage signal to said electrode (El) and carrying out a sampling of the response signal, calculating, on the basis of the sequence of sampled values, the characteristic parameters of the waveform of the signal for each of the experimental conditions, for the purposes of calculating a correlation function, on the basis of the acquired experimental data, capable of unambiguously correlating the power and the further significant parameter of the combustion characteristics with the characteristic parameters of the waveform of the signal at the electrode. The second phase comprises the steps of applying a voltage signal to the electrode (El) and carrying out sampling of the resultant response signal, calculating, on the basis of the sequence of sampled values, the characteristic parameters of the waveform of the response signal at the electrode, and calculating the estimated value of the desired combustion characteristic by using the correlation function.