Heater Flame Presence Control During Power Modulation
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Solution Overview
Problem
Existing heating appliances face challenges in reliably detecting stable flames during modulation due to unreliable signals from flame detectors, particularly at low power levels or high hydrogen content, leading to unnecessary shutdowns and safety risks.
Innovation Solution
Activate the ignition device during modulation to ensure immediate reignition of the flame, even if detected as extinguished, and use an evaluation unit to verify the ignitability of the air-fuel mixture, allowing delayed signal evaluation from flame detectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single flame detector is used to reduce cost and complexity, then device complexity is reduced, but reliability of flame detection deteriorates during modulation
Solution Approach 1:
The ignition device is activated in advance during modulation operations to create ignition conditions before potential flame extinction occurs. This preliminary action ensures that if flame extinction happens during modulation, the flame can be immediately reignited without causing unnecessary shutdowns, thereby maintaining reliable operation with a single flame detector.
2Measurement precision
If flame detection threshold is made sensitive to detect low power flames, then measurement precision is improved, but false detection of flame extinction increases during modulation
Solution Approach 1:
By activating the ignition device during modulation, the system creates a permissive environment where brief flame extinction or detector false readings do not trigger shutdowns. The ignition device ensures immediate reignition, allowing the system to tolerate less sensitive detection thresholds during modulation without compromising safety.
3Object-affected harmful factors
If shutdown threshold is lowered to ensure safety, then safety is improved, but unnecessary shutdowns increase due to false flame extinction signals during modulation
Solution Approach 1:
The ignition device is activated during modulation to pre-establish ignition capability. This allows the system to maintain stricter shutdown thresholds for safety while preventing false shutdowns during modulation, as any brief flame extinction would be immediately corrected by the pre-active ignition device.
Solution Approach 2:
The system provides a cushion of safety by having the ignition device ready to act immediately during modulation. This beforehand preparation creates a buffer that allows the system to tolerate brief flame extinctions or false detector signals without actually shutting down, thereby maintaining productivity while preserving safety.
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
Ensures safe and reliable operation by preventing unnecessary shutdowns and rapid reignition of flames, enhancing safety and availability during power modulation.
Implementation Method 1
typically consists of an ignition electrode supplied with high voltage by ignition electronics, capable of generating an electric arc
Implementation Method 2
a combustion process is underway
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a method and an arrangement for ensuring the presence of flames (16) in a combustion chamber (15) during modulation of the power output of a heating appliance (1), wherein an ignition device (12, 14, 17) in the combustion chamber (15) is activated during modulation. The invention increases the safety and availability of a heating appliance (1) during power modulation, thereby avoiding unnecessary shutdowns due to faulty or time-delayed signals from a flame detector and ensuring safe and rapid reignition if the flames (16) go out during the modulation process.