Fuel Injection Control System for Stable Combustion
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Solution Overview
Problem
Existing fuel injection systems for internal combustion engines face challenges in ensuring stable combustion of fuel during pilot injections, particularly when ambient temperature is low, atmospheric pressure is low, or the cetane number of fuel is low, leading to increased unburned fuel and misfires.
Innovation Solution
A fuel injection control system that includes an injection quantity calculator, injector driver, combustion state parameter acquiring circuit, stable combustion determining circuit, and combusted amount controller to adjust the number and quantity of pilot injections, and the pilot-to-pilot injection interval to create an enriched air-fuel mixture, enhancing ignitability and combustion stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pilot injection quantity is increased to ensure stable combustion, then the combustion stability is improved, but the unburned hydrocarbon emissions and engine noise increase
Solution Approach 1:
The pilot injection is divided into multiple sequential injection events (first pilot injection, second pilot injection, etc.) rather than a single large injection. This segmentation allows the total fuel quantity to be distributed across multiple smaller injections, ensuring stable combustion through cumulative fuel delivery while preventing excessive single-event fuel amounts that cause diffusion combustion and harmful emissions
Solution Approach 2:
The system employs periodic pilot injection events at specifically controlled intervals before the main injection. The injection timing and interval are optimized so that each pilot injection occurs at a stage where the combustion chamber conditions (temperature, pressure, oxygen availability) support complete and stable combustion, thereby preventing unburned hydrocarbons and reducing noise
2Reliability
If the pilot injection quantity is increased to avoid misfire, then the ignitability is improved, but the fuel diffusion increases leading to more unburned hydrocarbons
Solution Approach 1:
The total pilot injection fuel quantity is segmented into multiple smaller injection events. Each segment delivers a controlled fuel amount that is sufficient to establish ignition and combustion stability without exceeding the diffusion capacity of the combustion chamber, thereby preventing unburned hydrocarbon formation
Solution Approach 2:
The pilot injections are performed in advance of the main injection at optimized intervals, allowing the fuel to be gradually introduced and combusted in a controlled manner. This preliminary staged action ensures that combustion is established and stabilized before the main fuel delivery, preventing misfire while maintaining complete combustion
3Reliability
If multiple pilot injections are performed to enhance combustion stability, then the burning stability is improved, but the system complexity increases
Solution Approach 1:
The injection control system dynamically adjusts the number of pilot injection events, the fuel quantity per event, and the timing intervals based on real-time combustion state parameters (such as combustion pressure, temperature, and oxygen levels). This dynamic adaptation allows the system to achieve stable combustion across varying operating conditions without requiring a physically complex injection hardware configuration
Solution Approach 2:
The system incorporates feedback mechanisms that monitor combustion state parameters during the injection cycle and use this information to optimize the pilot injection strategy. By measuring combustion characteristics and adjusting subsequent injection parameters accordingly, the system achieves stable burning while maintaining relatively simple control logic
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
The system effectively ensures stable combustion of fuel by adjusting pilot injection parameters, reducing unburned hydrocarbons and engine noise, and improving the ignitability of fuel with lower cetane numbers, thereby enhancing the overall combustion efficiency.
Implementation Method 1
a fuel injector to spray the quantity of fuel, as calculated by the injection quantity calculator, into the combustion chamber
Implementation Method 2
a combustion state parameter representing a combustion state of the fuel within the combustion chamber
Data Source
AI summary
A fuel injection control system for an internal combustion engine is provided which is designed to perform pilot injection of fuel into the engine through a fuel injector prior to main injection. The system monitors a combustion state parameter representing a combustion state of the fuel within a combustion chamber of the engine which has been sprayed in the event of the pilot injection. When the combustion state parameter is determined as lying out of a stable combustion range where the fuel is to burn stably, the system changes the number of pilot injections to be executed prior to the main injection and/or the quantity of the fuel to be sprayed in each pilot injection, thereby enhancing the ignitability of the fuel in the pilot injection.