Hydrogen Fuel Pre-Heating for Cryogenic Delivery Control
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Solution Overview
Problem
Storing and delivering hydrogen fuel for aircraft propulsion poses challenges due to its low density, requiring high pressures or cryogenic storage, and necessitates additional control systems for temperature management and supply to gas turbines or fuel cells.
Innovation Solution
A hydrogen fuel delivery system with a heat exchanger, pre-heater line, control valves, and sensors to regulate temperature and pressure, utilizing control loops and look-up tables to manage fuel flow and heating, ensuring efficient delivery to gas turbines or fuel cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If liquid hydrogen is stored at cryogenic temperatures, then storage volume and weight are reduced, but temperature control complexity increases
Solution Approach 1:
The system pre-heats the liquid hydrogen fuel using a pre-heater line and burner before it enters the main heat exchanger. This preliminary heating action reduces the thermal shock to the heat exchanger and optimizes the subsequent heating process, thereby managing temperature control complexity while maintaining cryogenic storage benefits
Solution Approach 2:
The heating process is divided into multiple stages: a pre-heater line with burner for initial heating, followed by the main heat exchanger for further temperature increase. This segmentation allows each component to operate within optimal temperature ranges, reducing overall system complexity
2Reliability
If liquid hydrogen is heated from cryogenic temperatures, then fuel readiness for combustion is achieved, but energy consumption increases
Solution Approach 1:
The system uses a burner to combust a portion of the hydrogen fuel, converting the chemical energy into thermal energy that is then used to pre-heat the incoming liquid hydrogen. This converts what would be wasted combustion energy into a useful heating source, reducing overall energy consumption while ensuring fuel readiness
Solution Approach 2:
The hydrogen fuel itself serves as the heating source through the burner. By combusting a controlled amount of fuel to pre-heat the main fuel supply, the system uses the fuel's own energy content to prepare itself for combustion, minimizing external energy requirements
3Manufacturing precision
If control valves and heat exchangers are added to the fuel line, then temperature and pressure regulation is improved, but system complexity increases
Solution Approach 1:
The heat exchanger serves multiple functions: it heats the liquid hydrogen from cryogenic temperatures, condenses water vapor from the fuel, and potentially recovers heat for other system uses. This multi-functionality justifies the added complexity by providing several critical functions in a single component
Solution Approach 2:
The pre-heater line acts as an intermediary component between the cryogenic storage tank and the main heat exchanger. It provides a controlled path for a portion of the fuel to be heated by the burner, mediating the temperature transition and protecting the main heat exchanger from extreme thermal conditions
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 stable and efficient delivery of hydrogen fuel at the required temperature and pressure, preventing icing and maintaining system operability, thereby optimizing aircraft propulsion.
Implementation Method 1
a heat exchanger having first and second fluid paths, the fuel line passing through the first fluid path
Implementation Method 2
a burner between the pre-heater line inlet and the heat exchanger
Data Source
AI summary
A hydrogen fuel delivery system (300) comprises a fuel line (312) having an inlet (315) and an outlet (316), a liquid fuel pump (307) configured to provide a flow of liquid hydrogen fuel from a hydrogen fuel storage tank (308) to the fuel line inlet (315), a heat exchanger (306) having first and second fluid paths (313, 314), the fuel line (312) passing through the first fluid path (313), a pre-heater line (317) having an inlet (318) connected to the fuel line (312) between the fuel line inlet (315) and the heat exchanger (306), the pre-heater line (317) comprising a first control valve (301) and a burner (305) between the pre-heater line inlet (318) and the heat exchanger (306), the pre-heater line (317) passing through the second fluid path (314) of the heat exchanger (306) towards a pre-heater line outlet (319), a second control valve (302) in the fuel line (312) between the heat exchanger (306) and the fuel line outlet (316), a first temperature sensor (321) configured to measure a first fuel temperature (T1) in the fuel line (312) between the heat exchanger (306) and the second control valve (302), and a control system (400) configured provide a first control signal (CV1) to control operation of the first control valve (301) dependent on an input target temperature (T1Target) compared to the first fuel temperature (T1) and on a measure of fuel flow (mbfuel) through the pre-heater line (317).