Prechamber Gas Engine Fuel Swirl Flow Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In pre-combustion-chamber type gas engines, the check valve's differential pressure-based fuel gas supply can lead to inefficient combustion due to premature outflow of ignition fuel gas, resulting in reduced thermal efficiency and increased fuel consumption.
Innovation Solution
The gas supply channel for the pre-combustion chamber is positioned to create a swirl flow within the chamber, enhancing the trap effect by extending the residence time of ignition fuel gas and promoting uniform mixing with the air-fuel mixture, thereby reducing non-combusted fuel outflow and improving combustion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a check valve is used to supply ignition fuel gas based on differential pressure, then the facility size and cost are reduced, but the ignition fuel gas may outflow prematurely from the pre-combustion chamber, reducing combustion efficiency
Solution Approach 1:
The gas supply channel is designed with a curved configuration that directs fuel gas flow along the wall surface of the pre-combustion chamber. This curved path creates a Coanda effect that attaches the fuel gas stream to the chamber wall, preventing premature outflow through the nozzle while maintaining the simple check valve system.
Solution Approach 2:
The wall surface of the pre-combustion chamber acts as an intermediary between the fuel gas supply and the combustion process. By directing fuel gas to flow along the wall surface, the chamber wall mediates the fuel distribution, ensuring proper mixing and preventing direct outflow that would occur with straight-channel injection.
2Reliability
If fuel gas is supplied at high pressure to ensure sufficient ignition fuel in the pre-combustion chamber, then combustion can be maintained, but excessive fuel may outflow and thermal efficiency decreases
Solution Approach 1:
The curved gas supply channel creates a controlled flow pattern that utilizes the Coanda effect to attach fuel gas to the chamber wall. This allows sufficient fuel pressure to be maintained for reliable combustion while the curved path prevents excessive fuel from directly exiting through the nozzle, reducing energy loss.
Solution Approach 2:
The gas supply channel is positioned and oriented to deliver fuel gas to a specific location along the pre-combustion chamber wall where mixing with air-fuel mixture occurs. This localized delivery ensures sufficient fuel is available for ignition while preventing over-supply that would cause outflow and efficiency loss.
3Device complexity
If the gas supply channel opens directly into the pre-combustion chamber, then fuel gas supply is simple, but the fuel gas does not mix uniformly with air-fuel mixture and combustion efficiency is reduced
Solution Approach 1:
The curved gas supply channel creates a swirling flow pattern that promotes uniform mixing of fuel gas with air-fuel mixture in the pre-combustion chamber. The curved path generates rotational motion that enhances mixing while maintaining a relatively simple single-channel configuration without complex injectors or multiple openings.
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 improves combustion efficiency by reducing excessive fuel supply and enhancing thermal efficiency, while also simplifying the engine design and reducing costs by minimizing the need for excessive ignition fuel.
Implementation Method 1
the gas supply channel for the pre-combustion chamber is positioned so as to face into an inner peripheral surface of the pre-combustion chamber... create a swirl flow within the chamber, enhancing the trap effect by extending the residence time of ignition fuel gas
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
An object is to improve a trap effect to trap ignition fuel gas supplied to a pre-combustion chamber and reduce an amount of non-combusted ignition fuel gas flowing out of the pre-combustion chamber to suppress a decrease in combustion efficiency. A pre-combustion-chamber type gas engine includes: a pre-combustion chamber Sr disposed on a cylinder head portion 10; a spark plug 20 disposed on an upper part of the pre-combustion chamber Sr; a pre-combustion-chamber gas supply mechanism configured to supply ignition fuel gas "g" to the pre-combustion chamber Sr via gas supply channels for the pre-combustion chamber 22a and 22b with an opening on an upper part of the pre-combustion chamber Sr; and a check valve 24 disposed in the gas supply channel 22b for the pre-combustion chamber. The opening of the gas supply channel 22a for the pre-combustion chamber is disposed on a lower surface of a cover member 16 forming the pre-combustion chamber Sr or on an upper section of a side wall of a pre-combustion-chamber member 14, the opening facing in a tangent direction of a side-wall inner peripheral surface 14a of the pre-combustion-chamber member 14. The ignition fuel gas "g" supplied to the pre-combustion chamber Sr forms a swirl flow s1 which swirls about a longitudinal axis x of the pre-combustion chamber Sr inside the pre-combustion chamber Sr.