Aircraft Propulsion Assembly With Double-Walled Hydrogen Heating Duct
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Solution Overview
Problem
Existing aircraft propulsion systems face challenges in safely and efficiently heating dihydrogen before combustion to enhance fuel efficiency, particularly in the case of dihydrogen fuel.
Innovation Solution
A propulsion assembly with a double-walled supply duct and a bypass chamber that transfers heat energy from hot combustion gases to dihydrogen using a heat exchanger system, ensuring safety through a separate outer volume and leak detection mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-walled supply duct is used to transport dihydrogen, then the device complexity is reduced, but the safety level deteriorates due to potential leaks
Solution Approach 1:
The supply duct is segmented into a double-walled structure with an inner wall and an outer wall, creating separate compartments. This segmentation allows the system to maintain safety by isolating dihydrogen in the inner volume while providing a protective outer shell, thus resolving the contradiction between safety and complexity.
Solution Approach 2:
The inner wall containing dihydrogen is nested within the outer wall structure. This nested configuration allows the simpler inner duct to be protected by the outer wall, providing enhanced safety without completely redesigning the basic duct function. The nesting principle resolves the contradiction by layering protection around the core functional element.
2Productivity
If dihydrogen is heated before combustion, then the combustion efficiency is improved, but the safety risk increases due to handling hot dihydrogen
Solution Approach 1:
A thermal intermediary system is introduced between the dihydrogen supply and the combustion chamber. Hot combustion gases from the exhaust nozzle serve as the intermediary heating medium, transferring heat through the duct walls to the dihydrogen in the inner volume. This intermediary approach allows heating to occur indirectly, improving combustion efficiency while maintaining safety by preventing direct contact between hot gases and dihydrogen.
Solution Approach 2:
The patent replaces direct thermal contact (mechanical heat transfer) with indirect thermal contact through conductive heat transfer through the duct walls. Instead of physically mixing hot gases with dihydrogen, the system uses the duct walls as heat transfer medium, substituting a potentially unsafe mechanical mixing process with a safer conductive heat transfer process.
3Use of energy by moving object
If hot combustion gases are used to heat dihydrogen, then the energy efficiency is improved, but the harmful factors increase due to potential contamination
Solution Approach 1:
The duct walls serve as a thermal intermediary that allows heat transfer from combustion gases to dihydrogen without allowing direct mixing or contamination. This intermediary barrier maintains energy efficiency by enabling heat transfer while preventing harmful factors such as combustion product contamination of the dihydrogen supply.
Solution Approach 2:
The harmful contaminants are extracted or separated from the heat transfer process by using only the thermal energy of combustion gases without allowing the gases themselves to contact the dihydrogen. The system extracts the useful thermal property while leaving behind the harmful contaminants in the exhaust stream.
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 effectively heats dihydrogen before combustion, enhancing fuel efficiency while maintaining high safety standards by isolating dihydrogen in case of leaks, using a double-walled duct and leak detection systems.
Implementation Method 1
a heat exchange system arranged at the exhaust nozzle for ensuring heat energy is transferred to the dihydrogen of the propulsion system
Data Source
AI summary
A propulsion assembly having a fairing, a combustion chamber housed in the fairing, an exhaust nozzle delimited by a nozzle wall, a dihydrogen tank, a double-walled supply duct between the tank and the combustion chamber that has an inner wall delimiting an inner volume for the circulation of the dihydrogen and, around it, an outer wall delimiting an outer volume, and a bypass chamber, which is positioned around the nozzle wall and in which is made an upstream orifice for the introduction of the combustion gases and a downstream orifice for the discharge of the combustion gases, and wherein the supply duct has a portion arranged in the bypass chamber.