Fuel Injector Flat Sealing Surface for High-Pressure Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Challenges exist in creating sealing configurations for fuel injectors that effectively limit leakage and maintain consistent fuel metering when dealing with high-pressure liquefied gaseous fuels, which can lead to boiling and harsh environmental conditions.
Innovation Solution
A fuel injector design featuring a valve assembly with a reciprocating valve body and a valve seal made of elastomeric material, including a flat sealing surface that contacts a valve seat to inhibit flow, and a return path to cool and recirculate fuel, enhancing sealing and metering consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sealing configurations are used in high-pressure fuel injectors, then the injector can deliver fuel under pressure, but leakage increases and sealing reliability deteriorates
Solution Approach 1:
The patent applies local quality by providing a flat sealing surface specifically at the valve seat contact area rather than relying on conventional elastomeric seals throughout. This localized flat surface design concentrates the sealing function where it is most needed - at the interface between the valve body and nozzle - thereby improving sealing reliability while preventing fuel leakage under high pressure conditions
Solution Approach 2:
The patent changes the sealing parameter from curved/elastomeric contact to a flat surface geometry. This parameter change allows for more consistent contact pressure distribution across the sealing interface, improving sealing performance and reducing leakage in high-pressure liquefied gaseous fuel injection applications
2Productivity
If the valve is opened to deliver fuel, then fuel flow increases, but pressure drop causes fuel boiling and harsh environmental conditions
Solution Approach 1:
The patent segments the fuel path into distinct zones - a return path that separates the high-velocity injection zone from the valve assembly area. This segmentation allows fuel that experiences pressure drop and near-boiling conditions to be redirected through the return path back to the inlet, preventing cumulative thermal effects and harsh environmental conditions from degrading the sealing components
Solution Approach 2:
The patent converts the harmful effect of pressure drop-induced fuel boiling into a beneficial cooling effect. By routing fuel through a return path that allows it to expand and potentially vaporize in a controlled manner, the system uses the expanding fuel to cool itself and the surrounding components, thereby mitigating the harsh environmental conditions that would otherwise damage sealing surfaces
3Reliability
If complex sealing configurations are used to prevent leakage, then sealing improves, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent extracts the sealing function from complex elastomeric seal configurations and reduces it to a simple flat surface geometry on the valve seat. This extraction eliminates the need for multiple sealing components, grooves, and elastomeric materials while maintaining effective sealing performance, thereby reducing device complexity and manufacturing difficulty
Solution Approach 2:
Instead of using soft elastomeric materials to conform to hard surfaces (conventional approach), the patent inverts the approach by providing a hard flat surface that provides the sealing interface. This inversion simplifies the sealing configuration by eliminating the need for complex elastomeric seal designs while achieving reliable sealing performance
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 design improves sealing and ensures consistent fuel delivery by minimizing leakage and maintaining fuel in a liquid state, reducing wear and simplifying manufacturing while accommodating misalignments.
Implementation Method 1
A valve seal is held by the valve body and is formed of an elastomeric material. The valve seal includes a flat sealing surface that faces the nozzle and is configured to contact the valve seat so as to inhibit flow of fuel through the orifice.
Implementation Method 2
a return path from the valve body to an inlet end of the fuel injector. The return path is configured to receive a portion of the liquid fuel from the valve body and recirculate the portion of liquid fuel to the inlet end
Data Source
AI summary
A fuel injector for liquefied gaseous fuel includes a housing defining a fuel path from an inlet end to an outlet end. A nozzle is disposed at the outlet end of the housing. The nozzle includes an orifice for delivering liquid fuel from the fuel injector and forms a valve seat. A valve assembly is disposed in the housing and is configured to control flow of fuel through the orifice. The valve assembly includes a reciprocating valve body that is movable within the housing between a closed position and an open position. A valve seal is held by the valve body and is formed of an elastomeric material. The valve seal includes a flat sealing surface that faces the nozzle and is configured to contact the valve seat so as to inhibit flow of fuel through the orifice.