Gas Burner Vortex Cooling for Hydrogen Flashback Prevention

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Solution Overview

Problem

Existing gas burners struggle to efficiently combust non-carbonous gases like hydrogen without causing flashback or premature combustion interruption, leading to high carbon monoxide emissions.

Innovation Solution

The method involves controlling the flow rate and distance of the mixture to extend the recirculation vortex to a fluid-cooled heat exchanger, cooling it there to prevent flashback and reduce nitrogen oxide levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the recirculation vortex is cooled at the heat exchanger to prevent flashback with hydrogen combustion, then flashback prevention is improved, but combustion stability deteriorates due to premature combustion interruption

Engineering Contradiction:
Improveflashback preventionVSAvoidcombustion stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by precisely controlling the distance between the outlet opening and heat exchanger (L/d between 0.5-2.0) and the flow rate (Re between 2000-10000) to optimize the recirculation vortex characteristics. This ensures the vortex extends to the heat exchanger for effective cooling and flashback prevention, while maintaining sufficient residence time and temperature for complete combustion of hydrogen, thus resolving the contradiction between flashback prevention and combustion stability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs dynamics by allowing the recirculation vortex to dynamically extend to the heat exchanger surface, creating a dynamic cooling effect that adapts to flow conditions. The vortex structure naturally adjusts its extent and intensity based on operating parameters, enabling effective flashback prevention during high modulation while maintaining combustion stability across varying load conditions

Inventive Principle:
Principle #15Dynamics

2Reliability

If the flow rate is increased to extend the recirculation vortex to the heat exchanger, then flashback prevention is improved, but nitrogen oxide emissions increase due to higher combustion temperatures

Engineering Contradiction:
Improveflashback preventionVSAvoidnitrogen oxide emissions
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by creating a localized cooling zone at the heat exchanger surface where the recirculation vortex makes contact. This localized cooling effectively prevents flashback at the critical outlet region while allowing the bulk combustion zone to maintain higher temperatures necessary for complete hydrogen combustion, thereby preventing both flashback and excessive nitrogen oxide formation

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The recirculation vortex acts as an intermediary between the combustion zone and the heat exchanger. It carries hot exhaust gases to the heat exchanger surface for cooling, creating a thermal barrier that prevents direct contact between high-temperature combustion products and the heat exchanger, thus preventing flashback while controlling nitrogen oxide emissions through controlled cooling

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Effectively prevents flashback and reduces nitrogen oxide emissions while maintaining stable combustion with hydrogen as fuel, even with high burner modulation.

Implementation Method 1

exhaust gas formed during combustion is brought into contact with a fluid-cooled heat exchanger

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the recirculation vortex is cooled at the heat exchanger

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

The mixture is subsequently combusted on the burner surface, generating a recirculation vortex

Methodology Applied
Scientific EffectVortex flow: Vortex Ring

Implementation Method 4

the mixture is burned on the burner surface forming a recirculation vortex

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP4295082B1Method for operating a gas burner
Publication Date: 2026.04.22 VIESSMANN HOLDING INTERNATIONAL GMBH
  • EP4295082B1 patent drawingFigure 1~3
  • EP4295082B1 patent drawingFigure 4~5

AI summary

The invention relates to a method for operating a gas burner, in which method: a mixture is formed from a fuel gas and air in a mixing chamber (1); the mixture is conveyed at a controlled feed rate through an outlet opening (2) in a burner surface (3) delimiting the mixing chamber (1); the mixture is combusted at the burner surface (3) to form a recirculation vortex; and exhaust gas forming during the combustion is brought into contact with a fluid-cooled heat exchanger (4) located at a distance from the outlet opening (2). According to the invention, the feed rate for the mixture and the distance between the outlet opening (2) and the heat exchanger (4) are selected in such a way that the recirculation vortex extends from the outlet opening (2) to the heat exchanger (4) and is cooled down at the heat exchanger (4).