Premixed Hydrogen Burner Excess-Air Regulation for Flashback Control
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Solution Overview
Problem
Hydrogen combustion in premixed gas burners poses a significant risk of flashback, especially during ignition, which can lead to explosions, and existing methods to reduce pollutants like NOx and CO2 emissions compromise burner efficiency and safety.
Innovation Solution
A method and device for controlling a premixed hydrogen burner that regulates the excess air factor λ to ≥2.5 during ignition and maintains it for 5 seconds, followed by gradual reduction to 1.3<λ<2.5, with continuous temperature monitoring and adjustment to maintain stable combustion, using sensors to manage airflow, fuel flow, and flame presence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If excess air factor is increased to minimize pollutant emissions, then NOx emissions are reduced, but burner efficiency deteriorates
Solution Approach 1:
The invention dynamically changes the excess air factor parameter based on operational phase. During ignition, λ is set to ≥2.5 to minimize NOx and ensure safety. During stable combustion, λ is reduced to 1.05-1.20 to maximize efficiency. This time-based parameter adjustment resolves the contradiction between emission control and efficiency.
Solution Approach 2:
The control system applies periodic action by switching between two distinct operational modes: ignition mode with high excess air (λ≥2.5) for a predetermined time period, followed by efficient combustion mode with lower excess air (λ=1.05-1.20). This periodic switching allows the system to achieve both low emissions during transition and high efficiency during steady operation.
2Object-generated harmful factors
If hydrogen is used as fuel gas to reduce CO2 emissions, then pollutant emissions are reduced, but flashback risk increases
Solution Approach 1:
The invention applies preliminary anti-action by establishing high excess air conditions (λ≥2.5) specifically during the ignition phase when flashback risk is highest. This pre-established protective condition prevents flashback before it can occur. The system maintains this protective state for a predetermined time after ignition until combustion is fully established and safe.
Solution Approach 2:
The control system performs preliminary action by pre-configuring the air-to-fuel ratio to a safe value (λ≥2.5) before and during the ignition process. This preliminary setup ensures that the mixture is inherently safer and less prone to flashback before the combustion process fully stabilizes, then transitions to optimal combustion conditions once ignition is confirmed.
3Loss of energy
If excess air factor is reduced to improve burner efficiency, then energy loss is reduced, but combustion stability deteriorates
Solution Approach 1:
The invention makes the excess air factor dynamic rather than static. The system automatically adjusts λ based on combustion phase: using high values (≥2.5) during ignition for stability and safety, then transitioning to optimized values (1.05-1.20) during steady combustion for efficiency. This dynamic adaptation allows the system to maintain stability when needed and improve efficiency when safe.
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
Reduces the risk of flashback and ensures safe, stable combustion with modulated power, while minimizing pollutant emissions and maintaining efficiency by managing excess air and temperature within safe limits.
Implementation Method 1
combustion of a premixed gas wherein the fuel gas is hydrogen
Implementation Method 2
using sensors to manage airflow, fuel flow, and flame presence
Implementation Method 3
combustion of a premixed gas wherein the fuel gas is hydrogen
Data Source
AI summary
A regulation method of a premixed gas burner substantially and/or essentially fed by hydrogen H2 as well as a device to carry out such method is described.