Fuel Vent Tank Catalyst for Ullage Inerting
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Solution Overview
Problem
Existing fuel systems face challenges in effectively inerting the ullage of fuel tanks to prevent fire and explosion hazards due to reactive components like oxygen and fuel vapors, particularly as the ullage volume increases during fuel consumption, requiring continuous inert gas addition or generation on board vehicles.
Innovation Solution
A fuel system with a vent tank containing a catalyst in a duct open to the ambient atmosphere, where fuel vapors from the ullage are fed to the catalyst to deplete oxygen and fuel vapors through a catalytic reaction, reducing the oxygen content and eliminating the need for inert gas distribution pipework, and incorporating a dehumidifying device to remove water vapor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If inert gas is stored in a pressurized tank on the vehicle for use on demand, then the inerting function is reliable, but the system weight increases and maintenance requirements increase
Solution Approach 1:
The system uses the vehicle's existing engine exhaust as the inert gas source, eliminating the need for separate pressurized storage tanks. The exhaust gases are naturally directed through the fuel tank ullage via the vent tank system, making the system self-sufficient and reducing overall weight.
Solution Approach 2:
The vent tank system serves multiple functions: it acts as both the inert gas delivery system and the fuel tank ventilation system. By integrating these functions, the patent eliminates redundant components and reduces system weight while maintaining reliability.
2Weight of moving object
If inert gas is generated on board the vehicle, then weight and maintenance requirements are reduced, but the system complexity increases
Solution Approach 1:
The system utilizes the vehicle's existing engine exhaust generation capability to provide inert gas, rather than requiring a separate onboard generation system. This approach reduces system complexity by leveraging already-present vehicle systems.
Solution Approach 2:
The patent combines the inerting function with the existing fuel tank ventilation system by using the vent tank and ductwork already present in the vehicle. This merging of functions simplifies the overall system architecture.
3Reliability
If catalytic inerting systems are used to oxidize fuel vapor and produce carbon dioxide, then the inerting effectiveness is improved, but the system requires complex distribution pipework
Solution Approach 1:
The patent extracts the catalyst from the fuel tank interior and places it in the vent tank's ductwork. This relocation eliminates the need for complex distribution pipework inside the fuel tank, as the catalytic reaction occurs in the exhaust pathway rather than requiring internal tank modifications.
Solution Approach 2:
The vent tank serves as an intermediary chamber where the catalytic reaction occurs. By positioning the catalyst in the vent tank ductwork rather than inside the fuel tank, the system achieves effective inerting without requiring complex internal distribution systems.
4Reliability
If oxygen rich ambient air enters the ullage through the vent, then the inerting effectiveness is reduced, but preventing this entry increases system complexity
Solution Approach 1:
The catalyst is positioned to treat the exhaust gases before they enter the fuel tank ullage through the vent. This preliminary catalytic oxidation of fuel vapors and reduction of oxygen content ensures that the gas entering the ullage is already inerted, preventing the need for additional protective measures.
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 solution effectively inertizes the ullage by reducing oxygen and fuel vapor content, saving weight and installation costs, and reduces maintenance needs by eliminating the need for inert gas distribution pipework and water drainage systems, while also addressing the issue of water contamination in fuel systems.
Implementation Method 1
a catalyst disposed in the duct, wherein the catalyst is adapted to deplete one or more reactive components of gas flowing through the duct by catalytic reaction
Implementation Method 2
take oxygen and fuel vapour from the ullage and pass these over a hot catalytic bed to oxidize the fuel vapour and produce Carbon dioxide and water vapour
Data Source
AI summary
A fuel system includes a fuel tank, a vent tank fluidically connected to the fuel tank ullage, the vent tank having a duct open to the ambient atmosphere and the interior of the vent tank, and a catalyst disposed in the duct, wherein the catalyst is adapted to deplete one or more reactive components of gas flowing through the duct by catalytic reaction. Also, a method for depleting one or more reactive components of gas in the fuel system, includes depleting one or more reactive components of gas flowing through the duct using the catalyst.