Return Flow Powered Turbine for Aircraft Fuel Systems
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Solution Overview
Problem
Traditional fuel systems for gas turbine engines face inefficiencies and increased weight due to un-burnt fuel recirculation, which results in energy losses and heat transfer issues, as they require additional pumps and valves to handle increased fuel flow, and reintroduce heated fuel into the fresh supply loop.
Innovation Solution
An improved fuel system redirects un-burnt fuel to a turbine upstream of the fuel tank, where its energy is harnessed by a generator to power aircraft systems, and then returns the fuel to the tank for mixing with fresh fuel, reducing the need for heavy pumps and components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If un-burnt fuel is recirculated through additional pumps and valves, then the fuel can be reintroduced into the supply loop, but the system weight increases and energy losses increase
Solution Approach 1:
The patent extracts the un-burnt fuel from the traditional recirculation path and directs it through a separate return line to a storage tank, eliminating the need for additional recirculation pumps and valves. This extraction approach reduces system weight while maintaining fuel recirculation capability.
Solution Approach 2:
The patent converts the harmful effect of un-burnt fuel (which would normally require energy-intensive recirculation) into a beneficial outcome by allowing it to drain naturally to the storage tank, reducing energy losses and system complexity.
2Reliability
If un-burnt fuel is recirculated through pumps, then the fuel can be reused, but energy losses and heat transfer loads increase
Solution Approach 1:
The patent eliminates the harmful energy losses associated with pumping un-burnt fuel by allowing it to flow naturally through gravity to the storage tank. This converts the previously harmful recirculation process into a beneficial energy-saving operation.
Solution Approach 2:
The un-burnt fuel serves itself by flowing naturally to the storage tank without requiring external pumping energy, reducing the overall energy consumption of the fuel system.
3Reliability
If un-burnt heated fuel is mixed with fresh fuel, then the fuel is recirculated, but the fresh fuel becomes heated reducing its heat extraction capacity
Solution Approach 1:
The patent extracts un-burnt heated fuel from the fresh fuel supply loop and directs it separately to the storage tank, preventing thermal contamination of the fresh fuel while maintaining recirculation functionality.
Solution Approach 2:
The patent segments the fuel system into separate paths: one for fresh fuel supply and another for un-burnt fuel return. This segmentation prevents mixing of heated and fresh fuel, maintaining optimal temperatures for heat extraction operations.
4Reliability
If larger pumps are employed to handle increased fuel flow, then un-burnt fuel can be recirculated, but system weight and costs increase
Solution Approach 1:
The patent removes the requirement for larger recirculation pumps by extracting un-burnt fuel from the main supply line and allowing it to drain naturally to the storage tank, maintaining flow handling capability without additional pumping weight.
Solution Approach 2:
Instead of using pumps to force un-burnt fuel back into the system, the patent inverts the approach by allowing fuel to flow naturally to the tank through gravity, eliminating the need for additional pumping capacity.
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 reduces weight and energy losses by converting un-burnt fuel energy into electrical power, enhancing fuel system efficiency and eliminating the need for excessive pumping, while avoiding the introduction of heated fuel into the fresh supply loop.
Implementation Method 1
A return loop within the fuel system delivers un-burnt fuel which is heated and pressurized. The turbine is positioned upstream from a fuel tank. The turbine extracts energy which in turn powers a shaft and energizes a generator.
Implementation Method 2
The turbine extracts energy which in turn powers a shaft and energizes a generator. The generator provides electrical power to electrical components of the aircraft.
Implementation Method 3
An improved fuel system redirects un-burnt fuel to a turbine upstream of the fuel tank, where its energy is harnessed by a generator to power aircraft systems
Data Source
Figure 1
Figure 2~3
AI summary
A fuel system (42) for an aircraft is provided having an improved fluid circuit and method of operation. Un-burnt fuel is directed via a return loop (54) towards a fuel tank reservoir (50). A turbine (74) is located in the return loop (54) and upstream from the fuel tank (50). The pressurized un-burnt fuel energizes the turbine (74) and the fuel passes to the fuel tank (50). The turbine (74) is harnessed to a generator (76) for providing a power (96).