Cyclone Fuel Vaporization for Lean Piston Engine Ignition
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Solution Overview
Problem
Gasoline-fueled piston internal combustion engines face challenges in achieving reliable ignition with lean mixtures due to uneven fuel distribution and incomplete fuel evaporation, leading to reduced fuel economy and increased complexity in existing solutions.
Innovation Solution
The solution involves heating the inlet airstream and fuel using engine waste heat, mixing the heated air with ambient air, and using small cyclones to create a high-velocity vortex for flash evaporation of fuel before it enters the engine cylinders, ensuring a homogeneous dry gas mixture for efficient combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If fuel is discharged into the inlet airstream in the form of finely divided liquid droplets, then fuel displacement of air is minimized and oxygen availability is maximized, but incomplete evaporation occurs leading to insufficient vapor mixture for reliable ignition
Solution Approach 1:
The system pre-heats the inlet airstream using exhaust gas heat exchange before fuel injection, creating optimal conditions for immediate and complete fuel vaporization. This preliminary thermal preparation ensures that fuel droplets evaporate completely within the shortened residence time, reliably producing sufficient vapor mixture for ignition under all operating conditions
Solution Approach 2:
The system dynamically adjusts inlet air temperature through exhaust heat exchange to optimize fuel vaporization rates. By controlling the thermal parameters of the inlet airstream, the system ensures complete evaporation of fuel droplets and maintains reliable ignition across varying engine loads and operating conditions
2Reliability
If a greater quantity of fuel is provided in the charge to ensure sufficient vapor mixture for ignition, then ignition reliability is improved, but fuel economy deteriorates
Solution Approach 1:
By pre-heating the inlet airstream before fuel injection, the system creates optimal vaporization conditions that allow complete fuel evaporation with minimal fuel quantity. This eliminates the need for excessive fuel enrichment, maintaining lean mixture operation and optimal fuel economy while ensuring reliable ignition
Solution Approach 2:
The system controls inlet air temperature to optimize the vaporization efficiency of the fuel charge. By adjusting thermal parameters, the system achieves complete evaporation of the exact stoichiometric fuel quantity needed, preventing both fuel deficiency (which would harm ignition reliability) and fuel excess (which would harm fuel economy)
3Stability of the object's composition
If droplet fuel is injected directly into the inlet port, then unequal mixture distribution is mitigated, but evaporation opportunity is reduced and some fuel remains in droplet form at ignition onset
Solution Approach 1:
The system pre-heats the inlet airstream to temperatures that ensure immediate and complete vaporization of injected fuel droplets. This preliminary thermal preparation compensates for the reduced evaporation time in direct port injection, ensuring complete fuel vaporization and uniform mixture distribution without fuel remaining in droplet form at ignition onset
4Quantity of substance
If heated air is used to achieve complete fuel evaporation, then fuel vaporization is improved, but charge density decreases and volumetric efficiency is reduced
Solution Approach 1:
The system converts waste exhaust heat, which would otherwise be lost to the environment, into a useful resource for pre-heating the inlet airstream. This heat recovery process provides the necessary thermal energy for complete fuel vaporization without requiring additional energy input that would compromise charge density or volumetric efficiency
Solution Approach 2:
The system carefully controls the degree of inlet air heating to achieve complete fuel vaporization while minimizing the impact on charge density. By optimizing the thermal parameters and using exhaust heat recovery, the system maintains acceptable volumetric efficiency while ensuring sufficient fuel vaporization for reliable ignition and complete evaporation
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 enables reliable ignition with leaner mixtures, improves fuel economy, and reduces pollutants by ensuring thorough mixing and complete evaporation of fuel, while being adaptable to existing engine types without significant complexity or efficiency loss.
Implementation Method 1
a heat exchanger for heating the inlet airstream
Implementation Method 2
discharged in atomised form into said vortices of heated air where it undergoes flash evaporation
Implementation Method 3
Each said small cyclone generates a sustained vortex of high velocity
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
Apparatus constituting part of an induction and fuel delivery system for a cylinder of a piston internal combustion engine comprising a small cyclone into which is tangentially discharged a flow of heated air to generate a sustained vortex of high rotational speed; a modulatable fuel injector delivering a flow of atomised fuel into said small cyclone wherein it underdoes flash evaporation and energetic mixing; a delivery duct connecting said small cyclone to the inlet tract of said cylinder wherein said vortex fuel-air mixture is mixed with heated induction air; and means to prevent overheating of said modulatable fuel injector.