Compression Ignition Engine Fuel Injection Temperature Control
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Solution Overview
Problem
Compression ignition internal combustion engines face challenges in achieving high energy efficiency while avoiding detonation and controlling emissions, particularly due to limitations in fuel reactivity and the need for complex dual fuel supply systems.
Innovation Solution
A method that controls combustion by varying the injection temperature of gasoline in a compression ignition engine, using a single fuel supply system, where a majority of the fuel is injected during the intake stroke at a lower temperature and a smaller fraction is injected at a higher temperature during the compression stroke, enhancing reactivity and preventing detonation without requiring high injection pressures or dual fuel systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If compression ratio is increased to improve energy efficiency, then energy efficiency is improved, but excessive detonation occurs which damages the cylinder and piston
Solution Approach 1:
The fuel injection is divided into multiple fractions with different temperatures. A first fraction is injected at a lower temperature during the intake stroke, and a second fraction is injected at a higher temperature during the compression stroke. This segmentation allows progressive combustion that prevents detonation while enabling high compression ratios for improved energy efficiency.
Solution Approach 2:
The invention changes the temperature parameter of the injected fuel fractions. By injecting fuel at different temperatures (lower temperature for the first fraction, higher temperature for the second fraction), the combustion process is controlled to avoid detonation while maintaining high compression ratios, thus improving energy efficiency without the harmful effects of excessive detonation.
2Device complexity
If a single injector and single temperature injection is used, then device complexity is reduced, but control of combustion and pressure gradient becomes difficult leading to detonation risk
Solution Approach 1:
The invention introduces dynamic control by varying the temperature of fuel fractions injected through a single injector. The first fraction is injected at a lower temperature and the second fraction at a higher temperature, allowing dynamic adjustment of combustion characteristics without requiring multiple injectors, thus maintaining simple device structure while improving combustion control reliability.
3Object-generated harmful factors
If high injection pressures (over 1000 bar) are used to prevent particulate emissions, then particulate emissions are reduced, but device complexity and energy consumption increase
Solution Approach 1:
The invention changes the temperature parameter of the injected fuel instead of relying on extremely high injection pressures. By injecting the second fraction of fuel at a higher temperature during the compression stroke, the fuel achieves better atomization and combustion without requiring injection pressures over 1000 bar, thus reducing particulate emissions while avoiding the need for complex high-pressure injection systems.
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 high compression ratios without detonation, improving energy efficiency above 45% and reducing emissions, including particulates and NOx, while simplifying the engine design and eliminating the need for high-pressure injection systems.
Implementation Method 1
a smaller fraction F2 of the quantity Q of fuel is fed by a feed system that is provided with active heating devices (12) and that heats the fuel to the injection temperature T
Implementation Method 2
the fraction F2 of the quantity Q of fuel is heated to the injection temperature T, so as to increase the reactivity of the fraction F2 of the quantity Q of fuel and to enable self-ignition
Data Source
AI summary
Method to control the combustion of a compression ignition engine with reactivity control through the injection temperature; the control method provides for the steps of: establishing a quantity of fuel to be injected into a cylinder; injecting a first fraction of the quantity of fuel fed by a first feed system without active heating devices, preferably equal to at least 70% of the quantity of fuel, at least partially during the intake and/or compression stroke; injecting a second fraction of the quantity of fuel fed by a second feed system provided with at least one active heating device, and equal to the remaining fraction of the quantity of fuel, into the cylinder at the end of the compression stroke and preferably at no more than 60° from the top dead center; and heating the second fraction of the quantity of fuel to an injection temperature of over 100° C., before injecting the second fraction of the quantity of fuel.