Precombustion Chamber Nozzle Asymmetry for Flame Propagation Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In precombustion chamber gas engines, the uneven flame propagation caused by the ignition device being offset from the central axis leads to variations in injection start timing and strength of the combustion flame, resulting in unstable combustion and potential knocking, which degrades thermal efficiency and output power.
Innovation Solution
The engine design includes specific configurations for the nozzle holes, such as varying distances and angles from the precombustion chamber central axis to the nozzle openings, and adjusting the shape of the nozzle holes to equalize the timing and strength of flame injection across the main combustion chamber, thereby controlling flame propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the ignition device is disposed away from the central axis of the cylinder, then the structure of the precombustion chamber can be simplified, but uneven flame propagation occurs causing variation in injection timing and strength
Solution Approach 1:
The patent applies local quality by making the nozzle holes have different distances from the precombustion chamber central axis depending on their position. Specifically, nozzle holes in the far-ignition region (opposite the ignition device) have shorter distances to the central axis, while nozzle holes in the near-ignition region (close to the ignition device) have longer distances. This asymmetric arrangement compensates for the uneven flame propagation caused by the offset ignition device, ensuring that combustion flames are injected uniformly across the main combustion chamber.
2Device complexity
If the nozzle holes are arranged symmetrically around the precombustion chamber central axis, then the structure is simplified, but flame propagation variation causes knocking and reduced efficiency
Solution Approach 1:
The patent applies asymmetry by deliberately making the nozzle holes have asymmetric distances from the precombustion chamber central axis. The key asymmetry parameter is that nozzle holes in the far-ignition region have shorter distances to the central axis compared to nozzle holes in the near-ignition region. This asymmetric configuration counteracts the asymmetric flame propagation from the offset ignition device, resulting in uniform combustion flame injection and improved engine efficiency without excessive knocking.
3Ease of manufacture
If the distance between nozzle holes and precombustion chamber central axis is uniform, then manufacturing is easier, but injection timing and strength vary across the main combustion chamber
Solution Approach 1:
The patent applies local quality by varying the distance parameter of nozzle holes from the precombustion chamber central axis based on their angular position. Nozzle holes in the far-ignition region are positioned at shorter distances from the central axis, while nozzle holes in the near-ignition region are positioned at longer distances. This localized variation in geometry compensates for the uneven flame propagation, ensuring uniform combustion performance.
4Stability of the object's composition
If the ignition device is positioned on the central axis, then flame propagation is uniform, but the precombustion chamber structure becomes more complex
Solution Approach 1:
The patent applies asymmetry in the nozzle hole arrangement to compensate for the asymmetric ignition device position. By making nozzle holes in the far-ignition region closer to the precombustion chamber central axis and nozzle holes in the near-ignition region farther away, the system creates a counter-asymmetry that balances the flame propagation from the offset ignition device, achieving uniform combustion without requiring the ignition device to be on the central axis.
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 flame propagation, reduces knocking, and improves engine efficiency by ensuring consistent combustion across the main combustion chamber.
Implementation Method 1
combusting an air-fuel mixture in a main combustion chamber (main chamber) by injecting a combustion flame generated in a precombustion chamber (auxiliary chamber) via a plurality of nozzle holes
Implementation Method 2
a combustion flame is generated and jetted via each of the nozzle holes disposed at a lower portion of the precombustion chamber, by which a lean premixed gas in the main combustion chamber is combusted
Data Source
AI summary
A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via a plurality of nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from a main chamber central axis of the main combustion chamber at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through a precombustion chamber central axis of the precombustion chamber and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion. The distance between the precombustion chamber central axis and a precombustion-chamber-side opening end, connected to the precombustion chamber, of a specific far nozzle hole which is at least one nozzle hole in the far-ignition region is shorter or longer than the distance between the precombustion chamber central axis and a precombustion-chamber-side opening end of a specific near nozzle hole which is at least one nozzle hole in the near-ignition region.