Heating System Fuel-Air Ratio Control via Double-Peak Combustion Analysis

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Solution Overview

Problem

Existing heating systems face challenges in maintaining optimal fuel-air ratios during operation, leading to increased pollutant emissions and system unavailability due to lengthy calibration processes that disrupt regular operation.

Innovation Solution

A method that generates a temporary fluid supply change with a double-peak structure to adjust combustion parameters, allowing for real-time determination of the target combustion parameter based on oxygen concentration and burner performance, enabling precise control of the fuel-air ratio without the need for special calibration cycles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a calibration cycle is performed to determine the target combustion parameter, then the precision of the combustion parameter is improved, but the system availability deteriorates due to operation interruption

Engineering Contradiction:
Improvecombustion parameter precisionVSAvoidsystem availability
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent applies preliminary action by performing a brief fluid supply change at the beginning of the control method to proactively determine the target combustion parameter before regular operation proceeds. This temporary intervention creates a double-peak structure in the combustion parameter that enables subsequent precise determination of the target value without requiring later calibration interruptions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements periodic action by using repeated fluid supply changes with a specific double-peak temporal structure. The combustion parameter is modulated periodically to generate characteristic peak patterns, allowing the control unit to extract the target combustion parameter through analysis of these periodic variations. This periodic modulation enables continuous calibration without sustained operation interruption.

Inventive Principle:
Principle #19Periodic action

2Measurement precision

If the gas burner is run over its entire power range for calibration, then the measurement precision of the combustion parameter is improved, but harmful emissions increase

Engineering Contradiction:
Improvecombustion parameter precisionVSAvoidpollutant emissions
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies partial action by using a temporary, limited fluid supply change rather than running the burner through its entire power range. The fluid supply parameter is adjusted briefly to create a controlled double-peak pattern in the combustion parameter, providing sufficient information for calibration without subjecting the system to excessive operating conditions that would generate high pollutant emissions.

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If a temporary fluid supply change is generated to create a double-peak structure in the combustion parameter, then the target combustion parameter can be determined during regular operation, but the control complexity increases

Engineering Contradiction:
Improvecontinuous operation capabilityVSAvoidcontrol complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by implementing a temporal profile for the fluid supply parameter that evolves over time to generate the double-peak structure. The fluid supply is dynamically adjusted according to a predefined pattern, creating characteristic temporal variations in the combustion parameter. This dynamic approach enables the system to extract calibration information during operation without requiring complex additional hardware.

Inventive Principle:
Principle #15Dynamics

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

This approach ensures continuous operation with optimized fuel-air ratios, minimizing pollutant emissions and eliminating the need for calibration interruptions, thereby maintaining system availability and precision in determining the target combustion parameter.

Implementation Method 1

In order to ensure optimal combustion, it is necessary to ensure the correct fuel-air ratio when operating gas burners. For this purpose, the gas burner is controlled on the basis of a combustion parameter measured by sensors

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP3715716B1Method for controlling a fuel/air ratio in a heating system and a control unit and a heating system
Publication Date: 2023.01.04 ROBERT BOSCH GMBH
  • EP3715716B1 patent drawingFigure 1
  • EP3715716B1 patent drawingFigure 2~3
  • EP3715716B1 patent drawingFigure 4~5

AI summary

The invention relates to a method (54) for adjusting and controlling a fuel-air ratio (56) in a heating system (46) with a sensor for detecting a combustion parameter (84), in particular an ionization current (86), which comprises the following steps: • Generating (58) a temporary, temporal fluid supply change (60) of a fluid supply parameter (62) which is intended to generate a temporal change of the combustion parameter (84), wherein the fluid supply change (60) is selected such that the temporal change of the combustion parameter (84) has a double-peak structure (94) which has at least a first peak (88), a first trough (90) and a second peak (92), • Determining (80) the first peak (88) and the second peak (92) of the temporal change of the combustion parameter (84) correlated with the temporal fluid supply change (60),• Determining (101) an oxygen concentration (103) as a function of a quotient of the first peak (88) and the second peak (92), • Determining (102) a first burner output parameter (104), • Determining (116) a target combustion parameter (130) based on the oxygen concentration (103) and the first burner output parameter (104), • Controlling the heating system (46) based on the target combustion parameter (130). The invention also relates to a control unit (18) configured to carry out the method (54) according to the invention, and to a heating system (46) with the control unit (18) according to the invention.