Dual Fuel Engine In-Cylinder Temperature Control
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Solution Overview
Problem
Existing dual fuel engine systems face challenges in optimizing fuel injection amounts and durations based on in-cylinder temperature progression, which affects the efficient ignition and combustion of alternative fuels.
Innovation Solution
The method involves calculating a crank angle timing term for in-cylinder temperature sufficient for autoignition of the first fuel, and adjusting the injection amount or duration of the first fuel based on this calculation to increase the in-cylinder temperature for igniting the second fuel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the injection amount and duration of the first fuel are increased to ensure autoignition, then the reliability of ignition is improved, but the precision of temperature control deteriorates
Solution Approach 1:
The system performs preliminary calculation of the crank angle timing term and expected in-cylinder temperature progression before fuel injection. This allows the injection amount and duration to be pre-determined based on predicted temperature conditions, ensuring reliable autoignition while maintaining precise temperature control through advance planning rather than reactive adjustment
Solution Approach 2:
The system uses feedback from calculated in-cylinder temperature progression to dynamically adjust the injection amount and duration of the first fuel. The control unit continuously monitors expected temperature conditions and modifies injection parameters accordingly, creating a closed-loop system that simultaneously ensures ignition reliability and maintains temperature control precision
2Manufacturing precision
If the injection amount of the first fuel is reduced to improve temperature control precision, then the manufacturing precision is improved, but the reliability of autoignition deteriorates
Solution Approach 1:
The system dynamically adjusts the injection amount and duration of the first fuel based on real-time calculation of in-cylinder temperature progression. Rather than using fixed injection parameters, the system adapts injection timing and quantity to match actual temperature conditions, allowing precise temperature control while ensuring sufficient fuel is injected to maintain reliable autoignition under varying conditions
3Productivity
If complex calculations are performed to determine optimal injection parameters based on temperature progression, then the productivity is improved, but the device complexity increases
Solution Approach 1:
The system replaces complex mechanical measurement and adjustment mechanisms with computational methods. Instead of using physical sensors and mechanical actuators to detect and adjust injection parameters, the system uses mathematical calculations of crank angle timing terms and expected temperature progression to determine optimal injection parameters, reducing mechanical complexity while maintaining high combustion efficiency
Solution Approach 2:
The system creates a computational model (copy) of the in-cylinder temperature progression that mirrors actual thermal conditions without requiring physical temperature sensors. This virtual temperature profile allows the control unit to predict optimal injection timing and quantity based on calculated rather than measured data, simplifying the control system while preserving combustion efficiency
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 enables more precise control over fuel injection, improving the efficiency and effectiveness of dual fuel engine systems by ensuring optimal in-cylinder temperature for autoignition and combustion.
Implementation Method 1
a small pilot injection of diesel fuel directly into a cylinder where the diesel autoignites
Implementation Method 2
increasing the in-cylinder temperature sufficiently via burning of the first fuel to ignite the second fuel
Data Source
AI summary
Operating an engine system includes calculating a crank angle timing term corresponding to an in-cylinder temperature sufficient for autoignition of a first fuel injected at a first injection location. Operating an engine system further includes calculating, based on the crank angle timing term, at least one of an injection amount or an injection duration, to increase the in-cylinder temperature sufficiently via burning of the first fuel to ignite a second fuel injected into a mixture of the first fuel and pressurized intake air. The first fuel may include a blend of dimethyl ether (DME), methanol (MeOH), and water. Based on expected progression of in-cylinder temperatures, and fuel injection amount and/or duration based thereon, desirable controllability of combustion phasing and/or other combustion properties may be realized.