Offset Pre-Combustion Chamber for Gaseous Fuel Engines
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Solution Overview
Problem
Existing pre-combustion chamber assemblies for internal combustion engines operating on gaseous fuel face challenges in stabilizing combustion events due to early flame extinction, primarily because the ignition point is not optimally positioned relative to the inner walls of the combustion chamber.
Innovation Solution
The pre-combustion chamber assembly features a main portion with a central axis extending in parallel to the longitudinal central axis with a predetermined offset, allowing for an ignition point that lies on the central axis, ensuring a uniform distance from the inner walls and promoting symmetric combustion within the pre-combustion chamber, which is then efficiently transferred to the main combustion chamber via flow transfer passages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the ignition point is positioned close to the inner walls of the combustion chamber, then the combustion can be initiated easily, but the flame extinguishes early due to wall quenching effects
Solution Approach 1:
The pre-combustion chamber is positioned asymmetrically with respect to the main combustion chamber, with its central axis offset from the longitudinal central axis of the main chamber. This asymmetric positioning creates optimal flame propagation paths that avoid early wall quenching while maintaining reliable combustion initiation, thereby resolving the contradiction between combustion stability and flame duration.
2Ease of manufacture
If the pre-combustion chamber is positioned centrally in the main combustion chamber, then the structure is symmetrical and easy to manufacture, but the combustion efficiency is reduced due to suboptimal flame propagation
Solution Approach 1:
The patent deliberately introduces asymmetry in the positioning of the pre-combustion chamber relative to the main combustion chamber. The offset between the central axis of the pre-combustion chamber and the longitudinal central axis of the main chamber is specifically designed to optimize flame propagation paths and combustion efficiency, overcoming the limitations of symmetric central positioning while remaining manufacturable.
3Speed
If the ignition device is positioned to maximize flame propagation speed, then the combustion event is rapid, but the flame contacts the walls too early causing extinction
Solution Approach 1:
The asymmetric positioning of the pre-combustion chamber creates optimized flame propagation paths that allow rapid combustion while avoiding early wall contact. The offset configuration ensures that the flame front travels through the most efficient path in the charge, maintaining high propagation speed without premature extinction at the chamber walls.
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 stabilizes and enhances combustion efficiency within the pre-combustion chamber, leading to improved thermal efficiency in the main combustion chamber by preventing early flame extinction and ensuring a uniform combustion event.
Implementation Method 1
Upon ignition of the air/fuel mixture within the pre-combustion chamber, the flames may advance through orifices provided in the pre-combustion chamber into the main combustion chamber, where the flames may ignite the main amount of fuel and air for operating the internal combustion engine.
Data Source
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AI summary
The present disclosure relates to a pre-combustion chamber assembly (60) for internal combustion engines operating at least partly on gaseous fuel. In case of an additional gaseous fuel supply within the pre-combustion chamber assembly (60), an ignition device is required to be displaced out of center due to a lack of installation place in a central region. Thus, the disclosed pre-combustion chamber assembly (60) may comprise a pre-combustion chamber main portion (92) having a main portion central axis (93) that may extend in parallel to pre-combustion chamber assembly longitudinal central axis (63) with a predetermined offset (91). The pre-combustion chamber assembly (60) may further comprise an ignition device configured to initiate a combustion event at an ignition point (99) within the main portion (92). The ignition point (99) may lie substantially on the main portion central axis (93).