Burner Air Ratio Control via Ionization Signal Calibration
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Solution Overview
Problem
Existing methods for controlling combustion air ratios in gas burners fail to ensure reliable operation when faulty states are detected, leading to comfort losses and potential safety issues.
Innovation Solution
A method that uses an ionization electrode to monitor combustion quality, adjusts blower speed and gas valve opening based on ionization signals, and employs a calibration cycle to maintain optimal air ratios, even in the presence of sensor errors, by switching to a backup mode that ensures heating and hot water supply while awaiting system correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the gas burner operates with strict lambda value control using ionization signals, then combustion efficiency is improved, but the system shuts down when sensor errors are detected, causing comfort loss
Solution Approach 1:
The patent establishes predetermined minimum and maximum blower power limits as safety cushions before faulty operation can occur. These limits act as pre-prepared protective boundaries that prevent the system from entering dangerous states, allowing continuous operation even when sensor errors are detected, thus resolving the contradiction between maintaining combustion efficiency and ensuring reliable continuous operation
Solution Approach 2:
The patent creates a backup control mode that copies the essential safety functions of the primary lambda-controlled system. When sensor errors are detected, the backup mode replicates safe operation parameters (blower power limits, gas valve control) without requiring the faulty ionization signals, thereby maintaining continuous operation while preserving combustion safety
2Object-affected harmful factors
If the system shuts off the gas burner upon detecting incorrect operating state, then safety is improved, but comfort and continuous operation are lost
Solution Approach 1:
The patent implements dynamic switching between two control modes: primary lambda-controlled mode for optimal efficiency and backup safety mode for continuous operation. The system dynamically adapts its control strategy based on sensor status, allowing it to maintain both safety and productivity by transitioning between modes rather than shutting down completely
Solution Approach 2:
The patent introduces blower power limits as an intermediary control parameter that mediates between the ionization sensor signals and the gas valve control. By using blower power as an intermediate variable with predetermined safety boundaries, the system can detect sensor errors while maintaining safe operation through the intermediary layer, preventing direct shutdown
3Loss of energy
If lambda value control is used to optimize combustion, then energy efficiency is improved, but the system becomes vulnerable to sensor errors affecting operation
Solution Approach 1:
The patent implements dual feedback mechanisms: primary feedback from ionization sensors for lambda optimization and secondary feedback from blower power monitoring for safety validation. The blower power feedback acts as an independent verification layer that can detect when primary sensors fail, maintaining reliability while preserving the energy efficiency benefits of lambda control through the primary feedback loop
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 continuous, efficient operation and comfort by maintaining heat load and efficiency within safe limits, even during sensor failures, by using ionization signals to control the system and trigger recalibrations when blower power limits are exceeded.
Implementation Method 1
An ionization electrode 3 provided in the area of the flames allows current to flow through the flames between the burner 7 and the ionization current 3
Data Source
Figure 1
AI summary
The invention relates to a method for controlling the combustion air ratio at a burner (7) for a heating appliance for generating heat, using an ionization sensor. In the event of implausible parameters, the blower (2) is operated at a predefined target air mass flow rate and the gas valve (1) at a predefined valve position, which, together with the target air mass flow rate under predefined conditions, results in a defined target combustion air ratio greater than 1. Then, the air mass flow rate is reduced while simultaneously measuring the ionization signal until a maximum of the ionization signal is detected. The air mass flow rate at which the maximum of the ionization signal was detected is then determined and stored.The air mass flow parameter is then multiplied by a previously designed factor to achieve a desired combustion air ratio, and the resulting air mass flow parameter is set.