Self-Adjusting Engine Performance via Methane Number Feedback

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Solution Overview

Problem

Existing engine systems fail to efficiently adjust performance parameters in response to variations in fuel quality, particularly for spark-ignited engines using gaseous fuels, leading to suboptimal carbon dioxide levels and inefficiencies.

Innovation Solution

A controller-based system that adjusts engine performance parameters using methane number determination, incorporating sensors and processors to optimize air-fuel ratios and fuel quantity based on exhaust and intake carbon dioxide levels, peak pressure centroids, and knock sensor data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the engine operates with fixed air-fuel ratio settings, then the control system is simple, but the engine efficiency deteriorates when fuel quality varies

Engineering Contradiction:
Improveengine efficiencyVSAvoidcontrol system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system measures exhaust CO2 levels and uses this feedback to continuously adjust the air-fuel ratio and injection timing. The controller monitors the actual CO2 output and compares it with target values, automatically modifying performance parameters to maintain optimal combustion efficiency regardless of fuel quality variations.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system determines its own fuel quality characteristics by measuring exhaust CO2 and calculating methane number internally. Rather than requiring external fuel quality sensors or manual intervention, the engine self-diagnoses fuel properties and self-adjusts its performance parameters accordingly, making the system autonomous and adaptive.

Inventive Principle:
Principle #25Self-service

2Loss of energy

If the engine adjusts performance parameters dynamically, then fuel efficiency improves, but the device complexity increases

Engineering Contradiction:
Improvefuel efficiencyVSAvoidsystem complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The controller performs multiple functions using a single integrated system: it measures exhaust CO2, determines methane number, calculates optimal air-fuel ratio, adjusts injection timing, and controls valve timing. This multi-functional approach achieves dynamic fuel efficiency optimization without requiring separate dedicated systems for each function, thereby limiting the increase in overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system dynamically changes key combustion parameters including air-fuel ratio, injection timing, and valve timing based on real-time exhaust CO2 measurements. By continuously adjusting these parameters in response to fuel quality variations, the system maintains optimal combustion efficiency and minimizes energy loss throughout operating conditions.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If the engine uses fixed combustion parameters, then the system is simple to operate, but carbon dioxide levels become suboptimal varying with fuel quality

Engineering Contradiction:
Improvecarbon dioxide productionVSAvoidoperation simplicity
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The system uses exhaust CO2 measurement as feedback to automatically determine the appropriate air-fuel ratio and combustion timing. The controller continuously monitors CO2 levels and adjusts performance parameters to achieve target CO2 production, eliminating the need for manual adjustment while maintaining optimal combustion efficiency across varying fuel qualities.

Inventive Principle:
Principle #23Feedback

4Productivity

If the engine optimizes air-fuel ratio based on methane number, then fuel utilization improves, but measurement and control complexity increases

Engineering Contradiction:
Improvefuel utilizationVSAvoidmethane number determination
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The system uses exhaust CO2 concentration as an intermediary measurement to indirectly determine fuel quality characteristics including methane number. Rather than requiring direct complex analysis of fuel composition, the system measures the easily obtainable exhaust CO2 level and uses it as a proxy to infer fuel properties and adjust combustion parameters accordingly, simplifying the measurement process while maintaining accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enhances engine efficiency and fuel utilization by dynamically adjusting performance parameters to match fuel quality, ensuring optimal carbon dioxide production and reduced emissions.

Implementation Method 1

an exhaust sensor that senses a level of exhaust carbon dioxide

Methodology Applied
Scientific EffectCarbon dioxide detection: Absorption Spectroscopy

Implementation Method 2

a cylinder pressure transducer that measures a cylinder pressure of the engine

Methodology Applied
Scientific EffectPressure measurement: Piezoresistive Effect

Implementation Method 3

at least one of a knock sensor and a cylinder pressure transducer

Methodology Applied
Scientific EffectVibration detection: Piezoelectric Accelerometer

Implementation Method 4

adjusting an engine performance parameter in response to the determined optimized air-fuel ratio

Methodology Applied
Scientific EffectCombustion optimization: Combustion

Data Source

PatentEP3859137B1System and method for self-adjusting engine performance parameters during fuel quality variation
Publication Date: 2025.08.27 CUMMINS INC
  • EP3859137B1 patent drawingFigure 1
  • EP3859137B1 patent drawingFigure 2
  • EP3859137B1 patent drawingFigure 3

AI summary

A system and method for self-adjusting engine performance parameters in response to fuel quality variations that includes an exhaust sensor for measuring a level of carbon dioxide present in an exhaust manifold, at least one of a knock sensor and a cylinder pressure transducer for determining a location of peak pressure and a centroid, respectively, a controller in communication with the exhaust sensor and the at least one of the knock sensor and the cylinder pressure transducer, the controller correlating a methane number of the fuel used by the engine to a brake specific carbon dioxide value calculated using the level of carbon dioxide measured by the exhaust sensor and the at least one of the centroid and the location of peak pressure, and an adjusting mechanism, wherein the adjusting mechanism adjusts an engine performance parameter based on the determined methane number.