Hydrogen Nozzle Cap Radial Protrusion Flow Guidance
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Solution Overview
Problem
Existing fuel gas injection systems for hydrogen internal combustion engines face challenges in maintaining the initial direction of hydrogen jets due to sonic or supersonic flow conditions, leading to difficulties in designing nozzle cap holes to direct the jets effectively and causing vortices and auto-ignition issues.
Innovation Solution
A nozzle cap design featuring a radial protrusion with an inner surface region to reduce crossflow and guide fuel gas flow towards the outlet, enhancing control over the outgoing fuel gas jets and improving combustion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the nozzle cap hole exit area is enlarged to accommodate sonic or supersonic hydrogen flow, then the fuel gas flow capacity is improved, but the ability to direct the jets in a wanted direction deteriorates and disturbing vortices are generated
Solution Approach 1:
The nozzle cap incorporates flow-guiding structures (radial protrusions and axially-extending side sections) that create localized flow control zones within the enlarged hole exit area. These structures divide the flow path into specific regions, allowing different parts of the enlarged opening to serve different functions: some areas accommodate high-volume sonic/supersonic flow while others maintain directional control through guided flow paths, thus resolving the contradiction between flow capacity and direction control.
Solution Approach 2:
The radial protrusions and axially-extending side sections act as intermediary flow-guiding elements between the enlarged hole exit area and the combustion chamber. These intermediaries shape and direct the hydrogen jet flow, preventing uncontrolled vortices while maintaining the benefits of the enlarged opening area for high flow capacity.
2Device complexity
If conventional nozzle designs are used for liquid fuels, then the nozzle structure is simple, but the flow guidance capability for gaseous hydrogen at sonic or supersonic conditions is insufficient
Solution Approach 1:
The nozzle cap is segmented into functional zones using radial protrusions and axially-extending side sections that divide the internal volume into flow-guiding channels. This segmentation creates distinct regions for flow acceleration, direction control, and vortex suppression, improving reliability for gaseous hydrogen injection while maintaining a relatively simple overall nozzle structure based on conventional designs.
3Volume of stationary object
If the nozzle cap contains residual hydrogen-containing gases, then the cap volume is utilized, but auto-ignition may occur at unfavourable timing
Solution Approach 1:
The flow-guiding structures (radial protrusions and side sections) create directed flow paths that extract and channel hydrogen flow away from stagnant zones where residual gases could accumulate. By designing the flow paths to continuously sweep through the cap volume and discharge efficiently, the design minimizes dead spaces where auto-ignition could occur, thus taking out the harmful residual gas accumulation while maintaining cap volume utilization.
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
The improved nozzle cap design allows for more dynamic direction control of hydrogen fuel gas jets, reducing vortices and auto-ignition risks, and enhancing the mixing of fuel and air for improved ignition and combustion events.
Implementation Method 1
the radial protrusion having an inner surface region for reducing a crossflow of the fuel gas flow inside the nozzle cap and guiding the fuel gas flow towards the at least one outlet
Implementation Method 2
A fuel gas injection arrangement for a hydrogen internal combustion engine may typically be operable at critical conditions at which the hydrogen flow becomes sonic or even locally supersonic
Data Source
AI summary
A nozzle cap for a fuel gas injection arrangement of an internal combustion engine has: a body part defining an inner volume for accommodating a part of a movable valve arrangement, an inlet for receiving gaseous fuel, and at least one outlet arranged at an axial end portion of the nozzle cap. The at least one outlet permits discharge of one or more gas jets of fuel into a combustion chamber of the internal combustion engine. The axial end portion of the nozzle cap has a radial protrusion extending from an inner side of the nozzle cap towards an axial center axis and is delimited in a circumferential direction by axially-extending side sections, said radial protrusion having an inner surface region for reducing a crossflow of the fuel gas flow inside the nozzle cap and guiding said fuel gas flow towards the at least one outlet.