Selective Turboexpander Coupling for Variable Hydrogen Fuel Flow
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Solution Overview
Problem
The use of hydrogen and methane-based fuels in gas turbine engines for aircraft requires high efficiency propulsion to manage fuel volume and weight, and existing systems face challenges in efficiently utilizing varying fuel flow rates.
Innovation Solution
Aircraft propulsion systems incorporating a turbo expander assembly with a selective coupler that connects to multiple load sources, including electric generators, using a clutch or valve assembly to selectively operate one or more turbo expanders based on fuel flow, allowing for efficient power generation across varying fuel flow conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If hydrogen-based fuel is used in gas turbine engines, then combustion efficiency and environmental performance are improved, but fuel volume and weight increase due to the need for specialized storage vessels
Solution Approach 1:
The system divides the fuel flow path into multiple segments, each serving a specific function: one segment directs fuel to the turbo expander for power generation, while another segment provides fuel to the combustor for thrust production. This segmentation allows independent optimization of each fuel utilization path, maximizing energy extraction before combustion.
Solution Approach 2:
The turbo expander performs preliminary energy extraction from the hydrogen fuel before it reaches the combustor. By expanding the fuel and generating power in advance, the system converts chemical energy to mechanical energy prior to combustion, reducing the total fuel volume needed while maintaining combustion efficiency.
2Adaptability or versatility
If multiple turbo expanders are used to handle varying fuel flow rates, then adaptability and efficiency are improved, but device complexity increases
Solution Approach 1:
The system employs dynamic coupling mechanisms that allow the turbo expander assembly to adapt its configuration based on fuel flow conditions. The coupler can dynamically connect or disconnect turbo expanders from the fuel flow path, enabling the system to optimize performance across varying operating conditions without requiring a completely redesign for each scenario.
Solution Approach 2:
The turbo expander assembly is designed with multi-functionality, where a single integrated assembly can handle multiple fuel flow rates and operating conditions. The assembly includes bypass pathways and selective couplings that allow it to function efficiently whether fuel flow is high or low, eliminating the need for completely separate systems for different operating regimes.
3Productivity
If a selective coupler is implemented to connect turbo expanders to multiple load sources, then power generation efficiency is improved, but device complexity increases
Solution Approach 1:
The selective coupler acts as an intermediary mechanism between the turbo expander assembly and multiple load sources. It provides a centralized control point that can distribute power to different loads (generators, pumps, actuators) based on system needs, simplifying the overall architecture compared to having direct connections from each turbo expander to each possible load.
Solution Approach 2:
The system merges multiple coupling functions into a single selective coupler assembly. Rather than having separate coupling mechanisms for each load source, the design combines these functions into one integrated coupler that can selectively connect the turbo expander power output to various loads, reducing the total number of moving parts and control systems required.
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 system achieves efficient power generation and reduced weight by utilizing multiple turbo expanders, accommodating varying fuel flow rates and providing redundancy, thus optimizing engine performance with hydrogen fuel.
Implementation Method 1
The turbo expander is rotationally driven by the fuel passing therethrough
Implementation Method 2
passing the fuel through an aircraft-system heat exchanger, a high pressure pump, a fuel-air heat exchanger
Implementation Method 3
passing the fuel through an aircraft-system heat exchanger, a high pressure pump
Implementation Method 4
the selective coupler comprises a clutch assembly configured to selectively connect the turbo expander to a first load source and a second load source
Data Source
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AI summary
An aircraft propulsion system includes aircraft systems (304) having at least one hydrogen tank (332) and an aircraft-systems heat exchanger (358) and engine systems having at least a main engine core, a high pressure pump (316), a hydrogen-air heat exchanger (324), and a turbo expander assembly. The main engine core includes a compressor section, a combustor section having a burner (310), and a turbine section. Fuel is supplied from the at least one fuel tank (332) through a fuel flow path (344), passing through the aircraft-systems heat exchanger (358), the high pressure pump (316), the hydrogen-air heat exchanger (324), and selectively through the turbo expander assembly, prior to being injected into the burner (310) for combustion. The turbo expander assembly is operably coupled to at least two load sources through a selective coupler and configured to selectively drive operation of the at least two load sources.