Multi-chamber Igniter for Lean Fuel Combustion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Engines operating on gaseous fuels with lean fuel mixtures experience poor combustion, misfires, and short spark plug life due to the poor ability of conventional spark plugs to effectively ignite lean fuel mixtures.
Innovation Solution
The use of a prechamber ignition system with an antechamber and igniter plug configuration, where the air/fuel mixture is ignited in a separate antechamber before being injected into the combustion chamber as high-velocity flame jets, creating turbulence and increasing pressure for more complete combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional spark plugs are used to ignite lean fuel mixtures, then the structure is simple, but combustion is poor resulting in misfires and incomplete combustion
Solution Approach 1:
The combustion chamber is divided into two separate chambers: a main combustion chamber and a secondary combustion chamber (antechamber). The spark plug is positioned in the secondary chamber to ignite the fuel-air mixture there first, creating a controlled ignition source that then propagates to the main chamber. This segmentation allows the ignition process to occur in a optimized environment separate from the main combustion zone, improving reliability without excessive complexity.
Solution Approach 2:
The secondary combustion chamber acts as an intermediary between the spark plug and the main combustion chamber. It provides a controlled environment where the spark can reliably ignite the lean fuel mixture, and the resulting flame then serves as the ignition source for the main chamber. This intermediary structure resolves the contradiction by decoupling the ignition function from the main combustion function.
2Reliability
If high energy spark is used to ignite lean fuel mixtures, then ignition effectiveness is improved, but spark plug life is reduced due to short life
Solution Approach 1:
The fuel-air mixture is prepared and positioned in the secondary combustion chamber before ignition occurs. The chamber is designed to concentrate the mixture around the spark plug, ensuring that the ignition energy is used efficiently on a pre-positioned target. This preliminary preparation of the combustion environment reduces the need for excessive spark energy and protects the plug from premature failure.
Solution Approach 2:
The secondary combustion chamber creates a localized region with optimized conditions for ignition, concentrating the fuel-air mixture in close proximity to the spark plug. This local concentration ensures efficient use of ignition energy and reduces the stress on the spark plug, extending its operational life while maintaining effective ignition.
3Loss of energy
If lean fuel mixture is used, then fuel economy is improved, but combustion quality deteriorates with misfires and incomplete combustion
Solution Approach 1:
The problem is solved by adding a spatial dimension to the combustion process through the secondary chamber. Instead of attempting to ignite the lean mixture directly in the main chamber, the system uses a separate secondary chamber positioned at a different spatial location and orientation. This dimensional separation allows the lean mixture to be ignited under optimized local conditions, then propagate the flame to the main chamber, maintaining both fuel economy and combustion quality.
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 configuration allows for consistent ignition of lean air/fuel mixtures without auxiliary fuel, achieving faster and more complete combustion, reducing spark plug wear, and prolonging ignition timing to lower cylinder pressures for longer plug life.
Implementation Method 1
The air/fuel mixture is ignited in a separate antechamber before being injected into the combustion chamber as high-velocity flame jets
Implementation Method 2
creating turbulence and increasing pressure for more complete combustion
Implementation Method 3
achieving faster and more complete combustion
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
Air/fuel mixture is received from a combustion chamber of the internal combustion engine into an enclosure about a flame kernel initiation gap between a first ignition body and a second ignition body. Air/fuel mixture received into the enclosure is directed into a flame kernel initiation gap. The mixture is then ignited in the flame kernel initiation gap.