Hydrogen Heating Glow Plug Sensing for Flame and Mixture Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing hydrogen-powered heating appliances face challenges in efficiently detecting and controlling combustion processes due to the unique properties of hydrogen flames, which are nearly invisible and emit less heat, and require multiple costly components like ignition electrodes, UV sensors, and lambda probes, leading to increased costs, complexity, and space requirements.

Innovation Solution

A single glow plug is used for ignition, flame detection, and gas-air mixture control by monitoring electrical voltage and resistance changes, integrating these functions into a single component to ensure reliable and space-saving operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple components (ignition electrode, UV sensor, lambda probe) are used to monitor combustion processes, then the reliability of flame detection is improved, but the device complexity and installation space increase

Engineering Contradiction:
Improveflame detection reliabilityVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the ignition electrode and flame detection functions into a single component. The ignition electrode serves dual purposes: initiating combustion and detecting flame presence through ionization current measurement, eliminating the need for separate UV sensors and lambda probes while maintaining reliable combustion monitoring

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The ignition electrode is designed to perform multiple functions simultaneously: ignition, flame detection via ionization current, and combustion process monitoring. This multi-functional approach reduces the total component count while ensuring reliable hydrogen combustion control

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

2Temperature

If thermocouples are used to monitor flame temperature, then temperature measurement is improved, but the gas flow distribution through the burner is affected leading to localized overheating

Engineering Contradiction:
Improveflame temperature measurementVSAvoidlocalized overheating
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent removes thermocouples from the burner structure entirely, extracting the temperature measurement function and replacing it with non-contact or minimally intrusive measurement methods that do not interfere with gas flow distribution or cause localized overheating

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses ionization current as an intermediary parameter to indirectly monitor combustion conditions without direct thermal contact. This allows temperature and combustion state monitoring while avoiding the harmful thermal effects of inserting thermocouples into the burner

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If thermocouples are attached to the burner surface, then flame presence detection is improved, but the durability is reduced due to insufficient resistance to flame contact

Engineering Contradiction:
Improveflame presence detectionVSAvoidthermocouple durability
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent employs the ignition electrode as a sacrificial or replaceable component designed to withstand flame exposure. By using a component specifically engineered for ignition conditions, the system accepts periodic replacement rather than attempting to use indefinitely durable but less effective materials

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

4Device complexity

If a single glow plug is used for ignition and detection, then the installation space and cost are reduced, but the measurement precision for hydrogen flame detection may be insufficient

Engineering Contradiction:
Improvenumber of componentsVSAvoidflame detection precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent monitors changes in electrical parameters (current, voltage, resistance) of the glow plug to detect flame presence and characteristics. By analyzing parameter changes rather than relying on a single fixed threshold, the system achieves precise hydrogen flame detection with a single component

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system continuously monitors the electrical parameters of the glow plug and uses this feedback to determine flame presence, adjust ignition timing, and control combustion. This closed-loop feedback enables precise detection and control using a single multi-functional component

Inventive Principle:
Principle #23Feedback

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

The solution reduces costs, installation space, and complexity while enhancing reliability by combining ignition, detection, and mixture control functions in a single glow plug, ensuring efficient hydrogen combustion.

Implementation Method 1

Activating the glow plug by applying a predetermined electrical voltage

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

Monitoring at least one electrical voltage and/or electrical resistance of the glow plug and detecting a sudden change in the electrical voltage and/or electrical resistance of the glow plug, wherein the sudden change exceeds a predetermined threshold and the sudden change is accompanied by the ignition of a flame in the combustion chamber

Methodology Applied
Scientific EffectIonization: Ionisation

Implementation Method 3

Determining a flame temperature using the glow plug

Methodology Applied
Scientific EffectThermal energy conversion to electrical signal: Thermistor

Data Source

PatentEP4414604B1Method for operating a heating device which can be operated with hydrogen, heating device and computer program
Publication Date: 2026.03.11 VAILLANT GMBH(DE)
  • EP4414604B1 patent drawingFigure 1

AI summary

A method for operating a hydrogen-powered heating appliance (1), wherein a mixture of a hydrogen-containing fuel gas and air is combusted in a combustion chamber (17) and a glow plug (12) is associated with the combustion chamber (17), the method comprising the following steps: a) detecting a combustible mixture in the combustion chamber (17), b) activating the glow plug (12) by applying a predetermined electrical voltage, c) monitoring at least one electrical voltage or electrical resistance of the glow plug (12) and detecting abrupt changes, d) determining a flame temperature using the glow plug (12). A heating appliance and a computer program are also specified.