Onboard Fuel Additive Concentration Control via Membrane Contactor
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Solution Overview
Problem
Aircrafts may receive fuel with lower concentrations of required additives due to shifting responsibility for additive incorporation from refiners to commercial entities, necessitating on-board monitoring and adjustment to ensure proper additive levels for fuel stabilization and performance.
Innovation Solution
A system comprising a fuel additive sensor, dispenser, and controller that monitors fuel additive concentrations and adjusts flow to maintain specified levels by diverting fuel through a membrane-based contactor for passive dosing, ensuring adequate additive presence in the fuel line leading to the engine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fuel additives are injected at refueling truck loading racks, then additive concentration can be controlled, but the system becomes dependent on external refueling infrastructure and cannot adjust to fuel variability onboard
Solution Approach 1:
The fuel system is segmented into multiple functional zones: the main fuel storage tank, the fuel additive dispenser system with membrane-based contactor, and the fuel line to the engine. This segmentation allows independent control of additive dosing separate from the main fuel supply, enabling onboard adjustment while maintaining reliable fuel delivery.
Solution Approach 2:
A membrane-based contactor serves as an intermediary device between the fuel stream and the additive reservoir. The membrane allows selective transfer of additive components into the fuel without direct contact between the additive and fuel streams, enabling precise control of additive concentration while maintaining system reliability.
2Ease of manufacture
If additive packages are designed for injection at refueling operations, then initial additive concentration is established, but no mechanism exists to validate or adjust concentration during fuel storage and transport
Solution Approach 1:
The system incorporates preliminary action by pre-positioning the fuel additive dispenser and membrane-based contactor within the fuel tank before fuel delivery. This allows the system to be ready to monitor and adjust additive concentrations immediately upon receiving fuel, without requiring external intervention or complex post-delivery validation procedures.
Solution Approach 2:
The system implements feedback control by continuously monitoring fuel additive concentration and automatically adjusting the amount of additive dispensed through the membrane-based contactor. This closed-loop feedback mechanism ensures precise measurement and maintenance of additive concentrations within specified ranges, resolving the contradiction between ease of manufacture and measurement precision.
3Temperature
If fuel temperature is increased for next generation aircraft performance, then thermal load capacity improves, but fuel stabilization becomes more difficult due to higher temperature effects
Solution Approach 1:
The system addresses the temperature-stability contradiction by changing the chemical composition parameters of the fuel through additive injection. The membrane-based contactor delivers specific additive packages that modify the fuel's chemical properties, enhancing its thermal stability and resistance to carbonaceous deposit formation even at elevated operating temperatures required for next-generation aircraft 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
Ensures proper fuel additive levels are maintained onboard, addressing the variability in fuel additive concentrations and ensuring the fuel meets performance and operability targets, particularly in environments with less regulated fuel standards.
Implementation Method 1
a passive fuel additive dosing system comprises a cartridge; a membrane-based contractor within the cartridge; a fuel inlet to the cartridge connected to receive diverted flow from the flow control device; a fuel outlet from the cartridge connected to return flow back to the fuel line; and an additive within the membrane-based contractor, the membrane-based contractor being arranged in the cartridge such that, with fuel in the cartridge, a fuel contact area with the membrane-based contractor is dependent on a fuel flow rate to passively dispense a proportional amount of the additive in to the fuel
Data Source
AI summary
A system for monitoring fuel additives on board a vehicle includes a fuel line carrying fuel from a fuel source to an engine; a fuel additive sensor configured to measure concentration of additives in fuel at a point along the fuel line; a fuel additive dispenser connected in parallel to the fuel line; at least one flow control device for controlling an amount of flow from the fuel line into the fuel additive dispenser; and a controller configured to receive input from the fuel additive sensor and to control the flow control device to adjust the amount of the flow from the fuel line into the fuel additive dispenser.