Combustion Device Control with Exhaust Oxygen Feedback
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Solution Overview
Problem
Existing combustion device control systems lack flexibility and efficiency, particularly in adjusting fuel-to-air ratios to optimize combustion performance and minimize emissions, especially during transitions and in the absence of sensor feedback.
Innovation Solution
A combustion device automation system that utilizes an oxygen-related sensor in the exhaust gas path to control and regulate fuel and air supply actuators, employing both open-loop and closed-loop operations, with characteristic curves for safe and efficient combustion management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If characteristic curves are predefined and burner output is fixed by a fixed function, then device complexity is reduced, but adaptability deteriorates because the system cannot adjust to changes in fuel composition or air density
Solution Approach 1:
The patent introduces feedback control using oxygen sensors (lambda sensors) in the exhaust gas path to detect actual oxygen concentration. This feedback signal is used to dynamically adjust the air-to-fuel ratio, allowing the system to adapt to changing fuel composition and air density conditions while maintaining controlled combustion. The feedback mechanism resolves the contradiction by enabling adaptability without requiring complete redesign of the control system.
Solution Approach 2:
The system transitions from static predefined characteristic curves to dynamic adjustment of combustion parameters. The control unit continuously modifies air and fuel supply based on real-time sensor data, enabling the system to adapt to varying operating conditions. This dynamic approach maintains simplicity while achieving versatility through continuous parameter optimization.
2Measurement precision
If air ratio is adjusted by changing air supply signal to keep lambda constant, then measurement precision of air ratio is improved, but productivity deteriorates because burner output changes with fuel composition requiring manual characteristic curve selection
Solution Approach 1:
The system uses feedback from oxygen sensors to continuously monitor and adjust the air-to-fuel ratio. Instead of manually selecting characteristic curves for different fuel compositions, the feedback control automatically maintains the desired lambda value by adjusting air supply based on actual exhaust gas oxygen concentration, thereby maintaining both precision and productivity.
Solution Approach 2:
The control system dynamically changes operating parameters (air supply, fuel supply) based on sensor feedback rather than relying on fixed characteristic curves. This allows the system to maintain precise air ratio control while keeping burner output stable across different fuel compositions, eliminating the need for manual intervention.
3Adaptability or versatility
If oxygen-related sensor is used for closed-loop control, then adaptability is improved, but device complexity increases due to additional sensor and control mechanisms
Solution Approach 1:
The control unit integrates multiple functions: it processes signals from oxygen sensors, calculates optimal air-to-fuel ratios, controls air and fuel actuators, and manages both open-loop and closed-loop operations. This multi-functionality reduces overall system complexity by consolidating control logic into a single intelligent controller rather than requiring separate dedicated systems for each function.
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
Enables flexible and efficient combustion control, optimizing performance and reducing harmful emissions by dynamically adjusting fuel and air supplies based on oxygen concentration feedback, ensuring safe operation even in sensor failure scenarios.
Implementation Method 1
an oxygen-related sensor (20) in the exhaust gas path (10) is exposed to an exhaust gas flow
Implementation Method 2
During operation of a combustion device, the fuel-to-air ratio must be adjusted
Data Source
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AI summary
Optimized control of a combustion device (1). Combustion device (1) comprising a combustion chamber (2), an air supply duct (11) leading to the combustion chamber (2), a fuel supply duct leading to the combustion chamber (2), a first actuator (3, 4, 7 - 9) selected from an air actuator (3, 4) acting on an air supply V̇L through the air supply duct (11), and a fuel actuator (7 - 9) acting on a fuel supply V̇B through the fuel supply duct, the combustion device (1) comprising a second actuator (7 - 9, 3, 4) selected from the fuel actuator (7 - 9) and the air actuator (3, 4), wherein the second actuator (7 - 9, 3, 4) is different from the first actuator (3, 4, 7 - 9), the combustion device (1) comprising an exhaust gas path (10), at least one oxygen-related sensor (20) in the exhaust gas path (10) and a regulating and/or control and/or monitoring device (13) with a memory in which a first characteristic curve (25, 35, 36) is stored.