Burner Combustion Opening Control for Low-NOx Stable Flames
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Solution Overview
Problem
Existing industrial burners struggle with high NOx emissions and complex monitoring issues, particularly when switching between flame and flameless oxidation modes, and are ineffective at lower heating chamber temperatures.
Innovation Solution
A burner design with a controlled fuel and air mixture, generating a stable flame through a narrow combustion chamber opening, combined with flame monitoring, achieves low NOx emissions by enhancing exhaust gas intake and allowing stable flame detection across varying temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If flameless oxidation mode is used to reduce NOx emissions, then NOx levels are reduced, but the system cannot achieve low NOx emissions in areas that have not yet reached the specified ignition temperature and requires complex monitoring
Solution Approach 1:
The burner dynamically switches between flame mode and flameless oxidation mode based on the heating chamber temperature. When the temperature reaches the ignition point, the system transitions to flameless oxidation for low NOx emissions; when temperature is below ignition point, it operates in flame mode to ensure effective heating and simple flame detection monitoring.
Solution Approach 2:
The system changes operational parameters (combustion mode) based on temperature conditions. By monitoring heating chamber temperature, the burner adjusts its operating state to achieve low NOx emissions when conditions permit, while maintaining operational simplicity and effectiveness when temperatures are lower.
2Object-generated harmful factors
If flameless oxidation mode is used, then NOx emissions are reduced, but flame monitoring becomes impossible as the flame goes out after switching
Solution Approach 1:
The burner dynamically switches between flame mode and flameless oxidation mode based on the heating chamber temperature. When the temperature reaches the ignition point, the system transitions to flameless oxidation for low NOx emissions; when temperature is below ignition point, it operates in flame mode to ensure effective heating and simple flame detection monitoring.
Solution Approach 2:
The system changes operational parameters (combustion mode) based on temperature conditions. By monitoring heating chamber temperature, the burner adjusts its operating state to achieve low NOx emissions when conditions permit, while maintaining operational simplicity and effectiveness when temperatures are lower.
3Object-generated harmful factors
If two separate fuel feeds with switchover are used, then flameless oxidation can be achieved for low NOx emissions, but the system requires complex monitoring and switchover mechanisms
Solution Approach 1:
The burner uses a single fuel feed system that serves dual purposes: it can operate in flame mode for simple monitoring and heating, or in flameless oxidation mode for low NOx emissions. This universal fuel delivery system eliminates the need for complex switchover mechanisms between separate fuel feeds while achieving both operational modes.
4Power
If a larger combustion chamber opening is used, then more heat is transferred to the heating chamber, but exhaust gas intake is reduced leading to higher NOx emissions
Solution Approach 1:
The system changes operational parameters (combustion mode) based on temperature conditions. By monitoring heating chamber temperature, the burner adjusts its operating state to achieve low NOx emissions when conditions permit, while maintaining operational simplicity and effectiveness when temperatures are lower.
Solution Approach 2:
The high-velocity exhaust gases exiting the combustion chamber opening are converted into a beneficial flow that draws in additional combustion air and maintains stable combustion. The exhaust gas flow itself becomes the driving force for proper air-fuel mixing and combustion stability, reducing NOx formation while maintaining heat transfer efficiency.
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 burner achieves NOx levels of 5 to 100 mg/Nm³ or 50 to 150 mg/Nm³ based on 3% O₂ in dry exhaust gas, with stable flame monitoring and effective operation from 300 to 500 °C, reducing the need for flameless oxidation and complex monitoring.
Implementation Method 1
A flame is generated in the mixing and combustion chamber, the heat from which is used to heat the boiler room
Implementation Method 2
the second mode involving flameless oxidation, which enables low NOx levels
Implementation Method 3
fuel and air are mixed and ignited in a combustion chamber
Data Source
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AI summary
The invention relates to a burner (10; 11; 12) for heating a heating space (55; 55'), with reduction of NOx emissions. The burner (10; 11; 12) comprises a mixing and combustion chamber (54; 54'), a mixing and igniting device (51) which is arranged in the mixing and combustion chamber (54; 54'), and a fuel supply (50) which is connected to the mixing and igniting device (51) and is designed to supply fuel to the mixing and igniting device (51). Furthermore, an air supply (30, 30') is provided, which is designed to supply at least one partial air flow (L1) to the mixing and combustion chamber (54; 54'). A combustion chamber opening (53; 53') opens the mixing and combustion chamber (54; 54') toward a heating space (55; 55') to be heated. In addition, control means (60) are designed to control a fuel flow (B) via the fuel supply (50) and to control at least one partial air flow (L1) via the air supply (30; 30'), the burner (10; 11; 12) and the control means (60) being designed for operation of the burner (10; 11; 12) with a stable flame (56; 56') which extends from the mixing and igniting device (51) into the heating space (55; 55') through the combustion chamber opening (53; 53'). The cross-sectional area of the combustion chamber opening (53; 53'), which area is relative to the burner power, lies in the range between 1.5 mm2/kW and 10 mm2/kW.