NOx Estimation Using Fuel Flow and Engine Parameters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal combustion engines produce unwanted NOx emissions due to peak combustion temperatures, and existing methods fail to accurately estimate NOx production for diagnostic and control purposes.
Innovation Solution
A method and system that monitor fuel flow rate and engine operating parameters, such as charge mass, composition, and temperature, to estimate NOx production using a product of these parameters and model constants, with the estimates stored in memory and updated per engine cycle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing methods are used to estimate NOx production, then the estimation process is simple, but the accuracy of NOx production estimation is insufficient for diagnostic and control purposes
Solution Approach 1:
The patent changes the parameters used in NOx estimation from simple fuel flow rate to a comprehensive set including fuel flow rate, charge mass, charge temperature, EGR fraction, and fuel timing. This parameter expansion enables accurate NOx production estimation while maintaining computational efficiency through structured mathematical modeling
Solution Approach 2:
The patent introduces an intermediary mathematical model that bridges the gap between measurable engine parameters and NOx production. The model uses intermediate calculations (such as charge mass derivation from charge flow and engine speed) to translate sensor data into accurate NOx estimates without requiring direct measurement
2Measurement precision
If multiple engine operating parameters are monitored to improve NOx estimation accuracy, then estimation precision improves, but the complexity of data collection and processing increases
Solution Approach 1:
The patent makes existing engine monitoring systems multi-functional by using the same sensor data (fuel flow, charge flow, engine speed, temperature) for both engine control and NOx estimation. This eliminates the need for separate dedicated NOx sensors while maintaining estimation accuracy
Solution Approach 2:
The estimation system serves itself by using internally generated engine parameters (such as charge mass calculated from charge flow and engine speed) rather than requiring external measurements. The system leverages its own operational data to produce accurate NOx estimates
Data Source
AI summary
A system and method are provided for estimating NOx produced by an internal combustion engine. The flow rate of fuel supplied to the engine and a plurality of engine operating parameters are monitored. NOx produced by the engine is estimated based on a product of the flow rate of fuel and a function of the plurality of engine operating parameters. The NOx estimate is stored in memory.