Dynamic Gas Blending Disablement with Cylinder-Specific Diesel Shots
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dual fuel engines face issues with over-fueling or under-fueling when dynamic gas blending is disabled due to the differential reaction times of diesel and natural gas fuel systems, leading to imbalanced fuel ratios in the combustion chamber.
Innovation Solution
A method and system that adjust primary fuel delivery by determining if secondary fuel has been injected before disabling blending, and if so, inject a pilot shot of primary fuel, or a full shot if not, to maintain balanced fuel ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If dynamic gas blending is disabled and diesel injectors are switched to full diesel shots, then the diesel fuel supply system responds faster to fuel mixture change, but some cylinders may be over-fueled due to natural gas already loaded in the combustion chamber
Solution Approach 1:
The system performs preliminary action by checking the status of gas admission valves and natural gas injection timing before disabling dynamic gas blending. This allows the control system to anticipate which cylinders will receive natural gas and adjust diesel injection accordingly, preventing over-fueling while maintaining fast response speed.
Solution Approach 2:
The system applies local quality by providing different diesel injection strategies to different cylinders based on their individual fueling status. Cylinders that have already received natural gas receive reduced or no diesel injection, while other cylinders receive full diesel shots, ensuring precise fuel mixture control across the engine.
2Manufacturing precision
If diesel injectors are delayed switching to full diesel shots when disabling DGB, then over-fueling is prevented, but some cylinders may be under-fueled
Solution Approach 1:
The control system performs preliminary assessment of each cylinder's fueling status by monitoring gas admission valve positions and natural gas injection timing before disabling DGB. This enables the system to determine in advance which cylinders need reduced diesel injection and which can receive full diesel shots, optimizing fuel injection efficiency while preventing both over-fueling and under-fueling.
Solution Approach 2:
The system dynamically changes the diesel injection parameter (injection quantity) based on real-time cylinder-specific conditions. By adjusting the diesel injection amount as a variable parameter rather than applying a uniform delay to all cylinders, the system maintains optimal fuel-air mixture ratios and engine performance during the transition period.
3Manufacturing precision
If uniform delay is applied to all diesel injectors when disabling DGB, then over-fueling is avoided, but it cannot account for individual cylinder natural gas injection status
Solution Approach 1:
The system implements local quality control by individually managing diesel injection for each cylinder based on its specific natural gas injection status. Each cylinder receives a customized diesel injection strategy (full shot, reduced shot, or zero shot) determined by whether its gas admission valve is open and whether natural gas is being injected, achieving precise fuel mixture control without requiring complex hardware modifications.
Solution Approach 2:
The control system uses feedback from sensors monitoring gas admission valve positions and natural gas injection timing to continuously adjust diesel injection quantities. This closed-loop control approach allows the system to adapt to real-time cylinder conditions and maintain optimal fuel mixture ratios while managing the complexity through software-based control logic.
Data Source
AI summary
A system and method for adjusting primary fuel, when blending of primary fuel and secondary fuel is disabled, is provided. The method includes disabling, at a blend disabling angle, blending of primary fuel and secondary fuel for the DGB; determining whether the secondary fuel has been injected for a current cycle for a cylinder prior to the blend disabling angle; in response to determining that the secondary fuel has been injected for the current cycle prior to the blend disabling angle, injecting a pilot shot of the primary fuel for the current cycle; and in response to determining that the secondary fuel has not been injected for the current cycle prior to the blend disabling angle, injecting a full shot of the primary fuel for the current cycle.