Fuel Return Turbine Drive for Retrofitted Gas Turbine Accessories
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Retrofitting additional accessories into a gas turbine engine without the complexity and expense of modifying the gearbox to provide a separate drive is challenging, especially when existing alternators do not supply sufficient power for advanced FADEC systems and additional accessories like weapon systems, radar, and electronic warfare systems.
Innovation Solution
Utilizing a return line downstream of the fuel pump to drive an added accessory turbine, which powers additional accessories such as a hydraulically driven alternator or weapon systems, by modifying the fuel supply system to provide excess fuel and controlling fuel pumps to ensure consistent power delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the gearbox is modified to provide a separate drive for a new accessory, then the accessory can be powered, but the complexity and cost of modification increases
Solution Approach 1:
The invention extracts the accessory drive function from the gearbox by utilizing the fuel pump return line. Instead of modifying the gearbox to provide separate drive, the fuel energy is extracted and directed through a turbine on the return line to power the accessory, thereby avoiding gearbox complexity while maintaining adaptability
Solution Approach 2:
The invention introduces a turbine as an intermediary device between the fuel return line and the accessory. This turbine converts the energy from pressurized fuel into mechanical work to drive the accessory, serving as a mediator that eliminates the need for direct gearbox modification
2Power
If existing alternators are used, then the system is simple, but sufficient power for advanced FADEC systems and additional accessories cannot be provided
Solution Approach 1:
The invention changes the operational parameters of the fuel supply system by modifying control schedules to provide excess fuel above standard values. This increased fuel flow through the return line enables the turbine to generate sufficient power for advanced FADEC systems and additional accessories like weapon systems, radar, and electronic warfare systems
3Power
If fuel pumps are controlled to provide excess fuel, then power for accessories is sufficient, but fuel consumption increases
Solution Approach 1:
The invention converts what would normally be wasted fuel (the return line fuel that is excess after combustor requirements) into a beneficial energy source. By placing a turbine in the return line, the previously wasted pressurized fuel energy is captured and utilized to power accessories, transforming a loss into a useful resource
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
Enables the retrofitting of additional accessories by harnessing existing fuel energy, providing sufficient power to FADEC systems and supporting advanced actuation and control systems, reducing complexity and cost.
Implementation Method 1
the returned fuel has been pressurized by a fuel pump, and it is known to place a turbine in the return line to capture the energy from the pressurized fuel, and drive accessories
Implementation Method 2
a fuel pump driven through the gearbox, to deliver fuel to the combustor
Data Source
Figure 1A~2B
Figure 1B~1C
Figure 2A
AI summary
A retrofit gas turbine engine (20) includes a compressor (44, 52), a combustor (56) and a turbine (46, 54). A tie shaft (80) is connected to rotate by the turbine (46, 54), and provide rotational drive into a gearbox (82). At least one fuel pump (104; 144; 124; 164) is connected to be driven by the gearbox (82). The at least one fuel pump (104...164) delivers fuel downstream toward the combustor (56), and also has a return line (109; 148; 136; 183, 174). An added accessory turbine (110; 150; 132, 138; 184, 176) is positioned on the return line (109...174), and drives an added accessory (111; 152; 134, 140; 186, 178) which has been retrofit added to an existing gas turbine engine (20).