Diesel Engine Fuel Blend Control via Exhaust Oxygen Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal combustion engines face challenges in accurately controlling the blend ratio of petrodiesel and biodiesel fuels due to variations in fuel injector performance and aging, affecting stoichiometric air/fuel ratios and heating values, which impact engine operation and performance.
Innovation Solution
A method involving monitoring oxygen concentration in exhaust gases, mass flowrate of intake air, and commanded fuel pulse to determine the stoichiometric air/fuel ratio and blend ratio of petrodiesel and biodiesel fuels, with a control module adjusting engine operation based on these determinations to maintain optimal engine performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fuel injector performance varies and degrades with aging, then manufacturing precision and reliability of fuel delivery are worsened, but the control system complexity increases to compensate for these variations
Solution Approach 1:
The system continuously monitors exhaust gas oxygen concentration and uses this feedback to calculate the actual air-fuel ratio. This feedback loop enables the control system to detect fuel injector performance variations and compensate for them by adjusting fuel delivery parameters, thereby maintaining reliable fuel delivery consistency without requiring overly complex hardware modifications.
Solution Approach 2:
The patent replaces complex mechanical fuel delivery control systems with an electronic control approach. Instead of using complex mechanical metering devices or multiple physical sensors, the system uses electronic sensors (oxygen sensor in exhaust) and computational algorithms to determine and adjust fuel delivery, simplifying the overall system while improving reliability.
2Productivity
If the stoichiometric air/fuel ratio is not accurately maintained, then combustion efficiency and engine performance are worsened, but the measurement and control precision requirements increase
Solution Approach 1:
The system uses a feedback mechanism where the oxygen sensor continuously monitors exhaust gas composition, and the control system adjusts fuel delivery based on the measured oxygen concentration. This closed-loop control maintains the stoichiometric air-fuel ratio within optimal ranges, improving combustion efficiency while using practical measurement precision rather than requiring ultra-precise sensors.
Solution Approach 2:
The system dynamically adjusts the air-fuel ratio parameter based on operating conditions and measured oxygen concentration. By changing the air-fuel ratio parameter in response to real-time feedback, the system optimizes combustion efficiency across varying engine loads and fuel blend compositions without requiring fixed, ultra-precise measurement systems.
3Stability of the object's composition
If fuel blend ratio is not accurately determined, then engine operation stability is worsened, but the complexity of fuel characterization and control increases
Solution Approach 1:
The system uses exhaust gas oxygen concentration as a feedback indicator to infer the fuel blend ratio. Instead of requiring complex fuel analysis systems or multiple sensors to directly measure blend composition, the system uses the oxygen sensor data combined with mass airflow and fuel pulse information to calculate the effective air-fuel ratio, which reflects the actual fuel blend being consumed. This simplifies fuel characterization while maintaining operation stability.
Solution Approach 2:
The patent introduces an intermediary calculation approach where the oxygen concentration measurement serves as a proxy indicator for fuel blend characteristics. Rather than directly measuring fuel composition (which would require complex sampling and analysis systems), the system uses exhaust gas oxygen levels as an intermediary to infer blend ratio, simplifying the overall system while maintaining accurate control for stable operation.
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 allows for precise control of engine operation by accurately determining the blend ratio, improving combustion efficiency and counteracting fuel injector variability, thereby enhancing engine performance and stability.
Implementation Method 1
monitoring oxygen concentration in an exhaust gas feedstream
Implementation Method 2
internal combustion engine configured to combust fuel in a compression-ignition combustion mode
Data Source
AI summary
A method for operating an internal combustion engine includes monitoring oxygen concentration in an exhaust gas feedstream, a mass flowrate of intake air, and a commanded fuel pulse of fuel. A blend ratio of biodiesel fuel and petrodiesel fuel of the fuel is determined. Engine operation is controlled in response to the blend ratio of biodiesel fuel and petrodiesel fuel of the fuel.