Split Fuel Injection Timing for Turbocharged Diesel Engine Efficiency
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Solution Overview
Problem
Conventional techniques for reducing specific fuel consumption in turbo-charged diesel engines often result in increased exhaust emissions, particularly NOx, due to suboptimal fuel-air mixtures and injection timing.
Innovation Solution
A split fuel injection method where a small pilot fuel quantity (1-5% of the total) is injected 20-90 degrees before top dead center, followed by a majority fuel quantity (95-99%) injected less than 5 degrees before top dead center, using a controller with timing/advance logic to optimize combustion efficiency and emission control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional single-stage fuel injection is used to reduce specific fuel consumption, then fuel efficiency improves, but exhaust emissions particularly NOx increase
Solution Approach 1:
The fuel injection process is segmented into two distinct stages: a first fuel injection at a first timing and a second fuel injection at a second timing. This segmentation allows the fuel to be injected in controlled portions, improving combustion efficiency and reducing specific fuel consumption while maintaining acceptable emission levels through optimized injection timing control
Solution Approach 2:
The invention changes the timing parameter by injecting the first fuel at a first timing and the second fuel at a second timing, where the timing difference is controlled to be within a specific range (10-80 degrees crank angle). This parameter optimization enables better fuel-air mixing and combustion efficiency, reducing specific fuel consumption without significantly increasing NOx emissions
2Use of energy by moving object
If fuel injection timing is advanced to improve combustion efficiency, then specific fuel consumption decreases, but combustion control becomes less stable
Solution Approach 1:
By segmenting the fuel injection into two stages with different timings, the invention achieves both advanced combustion (improving fuel efficiency) and stable combustion control. The first fuel injection occurs at an advanced timing to improve efficiency, while the second injection provides additional fuel at an optimized timing to maintain combustion stability
Solution Approach 2:
The invention dynamically adjusts the injection timings within optimized ranges: the first timing is set 20-90 degrees before top dead center, and the second timing is set 10-80 degrees before top dead center, with a controlled time difference. This dynamic timing control enables the system to adapt to varying operating conditions while maintaining both efficiency and stability
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 reduces specific fuel consumption while maintaining pollutant emissions within acceptable limits by enhancing fuel atomization and air utilization, thereby improving engine efficiency and controlling exhaust emissions.
Implementation Method 1
a fuel injection system injects fuel (e.g. diesel fuel) into compressed air within each of the engine cylinders to create an air-fuel mixture that ignites due to the heat and pressure of compression
Implementation Method 2
injecting fuel (e.g. diesel fuel) into compressed air within each of the engine cylinders to create an air-fuel mixture
Implementation Method 3
create an air-fuel mixture that ignites due to the heat and pressure of compression
Data Source
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AI summary
In certain embodiments, there is provided a method of operating a turbocharged system including injecting a first quantity of fuel into an engine cylinder at a first predetermined time during a second half of a compression stroke before a piston of the engine cylinder reaches top dead center of the compression stroke. The method further includes injecting a second quantity of fuel into the engine cylinder at a second predetermined time after the first predetermined time when the piston is advanced by a predetermined advance value before the piston reaches the top dead center of the compression stroke.