Hydrogen Fuel Conditioning Loop for Turbine-Driven Pump Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Challenges in conditioning liquid hydrogen for hydrogen fueled aircraft include the high power required to raise temperatures and pressures at the required flow rate, as well as controlling complex pumping and heating systems to produce the necessary conditions for combustion during all phases of flight.
Innovation Solution
A fuel system for a gas turbine engine comprising a main fuel conduit, a fuel pump, an auxiliary combustor, a fuel turbine, and a turbine bypass conduit, which allows for efficient and controllable temperature and pressure control of hydrogen fuel through a combination of mechanical and electrical power sources, including a fuel turbine that drives the pump and an auxiliary combustor to heat the fuel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If liquid hydrogen is warmed to higher temperatures and pumped to high pressures at high flow rates, then the required fuel conditions for combustion are achieved, but high power consumption is required
Solution Approach 1:
The fuel system uses the fuel itself as the heating medium through the auxiliary combustor, where a portion of fuel is burned to heat the main fuel stream. This self-heating approach eliminates the need for external power-consuming heating systems, resolving the contradiction between achieving required fuel temperature and minimizing power consumption.
Solution Approach 2:
The system merges the heating function with the fuel combustion process by using the auxiliary combustor to burn a portion of fuel and transfer heat to the main fuel stream. This integration combines thermal processing with fuel preparation, achieving temperature conditioning without separate power-consuming heating equipment.
2Stress or pressure
If liquid hydrogen is pumped to high pressures at high flow rates, then the required fuel conditions for combustion are achieved, but high power consumption is required
Solution Approach 1:
The fuel turbine is driven by the heated fuel itself, creating a self-powered pressure generation system. The thermal energy in the heated fuel directly drives the turbine, which then powers the fuel pump, eliminating the need for external power sources and reducing overall power consumption while achieving required fuel pressures.
Solution Approach 2:
The system creates a closed energy loop where the heated fuel possesses sufficient enthalpy to drive the turbine at the same pressure level it needs to be pumped to. This equipotential approach allows the fuel's own thermal energy to be converted into mechanical work for pressurization, minimizing external power requirements.
3Productivity
If complex pumping and heating systems are used to achieve required flow, pressures and temperatures, then the fuel conditioning is achieved, but the control complexity increases
Solution Approach 1:
The system merges multiple functions into integrated components: the auxiliary combustor simultaneously heats fuel and generates thermal energy for turbine drive, while the fuel turbine both drives the pump and is controlled by fuel flow characteristics. This functional integration reduces the number of independent control systems needed, simplifying overall control complexity.
Solution Approach 2:
The fuel turbine operates as a natural feedback mechanism where fuel flow rate and temperature directly determine turbine output power, which in turn automatically adjusts pump operation. This inherent feedback loop provides automatic adaptation to varying flight conditions without complex external control systems.
4Use of energy by moving object
If a fuel turbine is used to drive the fuel pump, then power consumption is reduced, but control of pump pressure and temperature becomes interdependent
Solution Approach 1:
The system segments fuel flow into two independent paths: one through the auxiliary combustor for heating and another through the fuel turbine for power generation. This segmentation allows independent control of thermal processing and mechanical power generation, enabling separate adjustment of fuel temperature and pump pressure despite the shared fuel source.
Solution Approach 2:
The system employs dynamic control elements including variable geometry turbine blades and controllable fuel flow splits between the auxiliary combustor and main fuel stream. These dynamic adjustments allow independent optimization of heating and power generation functions, maintaining ease of operation while using the turbine-driven pump configuration.
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 efficiently conditions hydrogen fuel by providing independent control over temperature and pressure, optimizing energy use, and ensuring stable combustion conditions across various flight phases.
Implementation Method 1
an auxiliary combustor downstream in fuel flow of the fuel pump, and configured to combust a portion of fuel diverted from the main fuel conduit and to heat a remainder of fuel in the main fuel conduit
Implementation Method 2
a fuel turbine downstream in fuel flow of the auxiliary combustor, the fuel turbine being configured to be driven by the heated fuel from the auxiliary combustor and configured to power the fuel pump
Data Source
AI summary
A fuel system for a gas turbine engine configured to combust hydrogen fuel. The fuel system includes a main fuel conduit, a fuel pump configured to operate on hydrogen within the fuel conduit to provide pressurised fuel to a core combustor of the gas turbine engine, an auxiliary combustor downstream in fuel flow of the fuel pump, and configured to combust a portion of fuel diverted from the main fuel conduit and to heat a remainder of fuel in the main fuel conduit, and a fuel turbine downstream in fuel flow of the auxiliary combustor. The fuel turbine is configured to be driven by the heated fuel from the auxiliary combustor and configured to power the fuel pump. The fuel system includes a turbine bypass conduit configured to selectively bypass fuel around the fuel turbine. A method of operation is also described.