Pilot Fuel Injection Control for Dual-Fuel Engine NOx Reduction
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Solution Overview
Problem
Existing control systems for pilot fuel injection in dual fuel engines do not accurately estimate NOx emissions levels and adjust pilot fuel injection accordingly, leading to inefficient engine operation, higher NOx emissions, and sub-optimal performance due to limited consideration of factors influencing NOx emissions and fuel quality.
Innovation Solution
A control system that determines combustion parameters, estimates NOx emissions levels, compares them to desired levels, calculates an NOx error, and adjusts pilot fuel injection quantity based on this error, while also accounting for a reactivity parameter representing the fuel mixture's cetane and methane numbers to dynamically optimize pilot fuel usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a small amount of diesel fuel is introduced to assist combustion of natural gas, then combustion is achieved, but NOx emissions increase due to fast combustion rates and high temperatures
Solution Approach 1:
The system dynamically adjusts the pilot fuel injection quantity based on real-time combustion parameters (cylinder pressure, temperature, heat release rate) to optimize combustion characteristics. The control system modifies injection timing and quantity continuously to maintain reliable combustion while minimizing peak temperatures that generate NOx emissions.
Solution Approach 2:
The invention changes key combustion parameters including pilot fuel injection timing, injection quantity, and combustion chamber pressure-temperature conditions. By controlling the rate of heat release and peak combustion temperature through parameter adjustment, the system achieves reliable natural gas combustion while reducing NOx formation.
2Reliability
If excess pilot fuel is used to ensure complete combustion, then combustion reliability improves, but NOx emissions increase due to high combustion temperatures
Solution Approach 1:
The control system implements closed-loop feedback by continuously monitoring combustion parameters (cylinder pressure, temperature, heat release rate) and adjusting pilot fuel injection quantity accordingly. This feedback mechanism ensures complete combustion while preventing excessive fuel injection that would cause high temperatures and NOx emissions.
Solution Approach 2:
The system uses precisely controlled partial action of pilot fuel injection rather than excessive fueling. By injecting only the necessary amount of pilot fuel required for reliable natural gas combustion, the system avoids the harmful effects of excess fuel while ensuring complete combustion.
3Reliability
If pilot fuel injection is increased to maintain combustion under varying engine loads, then combustion reliability is maintained, but NOx emissions increase
Solution Approach 1:
The system dynamically adapts pilot fuel injection parameters to varying engine load conditions. The control system continuously adjusts injection timing and quantity based on real-time combustion parameters, maintaining consistent combustion reliability across different loads while minimizing NOx emissions through optimized fuel delivery.
Solution Approach 2:
The invention implements load-dependent parameter changes in pilot fuel injection. By modifying injection timing, duration, and quantity according to engine load and combustion conditions, the system maintains combustion consistency while reducing NOx emissions through optimized fuel-air mixing and controlled combustion rates.
4Object-generated harmful factors
If precise control of pilot fuel injection is implemented to minimize emissions, then NOx emissions are reduced, but control system complexity increases
Solution Approach 1:
The control system uses feedback from combustion parameters (cylinder pressure, temperature, heat release rate) to automatically adjust pilot fuel injection. This feedback-based approach reduces NOx emissions through precise control while managing system complexity by leveraging existing sensor data and established control algorithms.
Solution Approach 2:
The system uses its own combustion parameters (pressure, temperature, heat release rate) as feedback signals for control decisions. This self-service approach minimizes external sensing requirements and reduces control system complexity by utilizing internally generated information for optimization.
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 precise control of pilot fuel injection, reducing NOx emissions, improving engine efficiency, and ensuring compliance with emissions standards by dynamically adjusting to changing engine conditions.
Implementation Method 1
determining one or more combustion parameters of the dual fuel engine during operation of the dual fuel engine
Implementation Method 2
determining an estimated nitrogen oxides (NOx) emissions level based on the one or more combustion parameters
Implementation Method 3
controlling a quantity of pilot fuel injected into the dual fuel engine based on the NOx error
Implementation Method 4
a small amount of diesel fuel (e.g., pilot fuel) may be introduced into the combustion chamber and compressed, which leads to ignition of the diesel fuel and subsequent combustion of the natural gas
Data Source
AI summary
A control system for controlling pilot fuel injection in a dual fuel engine is disclosed. The control system may determine, using measurements from one or more sensors, one or more combustion parameters associated with the dual fuel engine during operation of the dual fuel engine. The control system may determine an estimated nitrogen oxides (NOx) emissions level based on the one or more combustion parameters, and may determine a NOx error based on a comparison between the estimated NOx emissions level and a desired NOx emissions level. The control system may control a quantity of pilot fuel injected into the dual fuel engine based on the NOx error.