Segmented Fuel Manifold Bellows Thermal Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engine fuel manifold systems face challenges in accommodating thermal expansion and contraction of the combustor casing, leading to issues like vibration, fatigue, and stagnant fuel causing coking, especially in high-temperature applications and staged combustion systems.
Innovation Solution
A segmented fuel distribution manifold system with dynamically connected fuel transfer tubes and a radially outer sealing tube that includes a resilient bellows section to accommodate thermal expansion, along with a drainage system for leak detection, ensuring all fuel lines remain relatively cool and preventing coking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If curved metal tubes are used to connect fuel lines, then thermal expansion and contraction can be accommodated, but vibration and fatigue problems occur
Solution Approach 1:
The fuel distribution manifold is divided into multiple modular segments that can independently accommodate thermal expansion. Each segment contains fuel distribution elements that can flexibly move relative to one another, allowing the system to expand and contract without generating excessive vibration or stress that would lead to fatigue failure.
Solution Approach 2:
The patent employs flexible bellows-like structures and expandable segments in the fuel distribution manifold. These flexible elements allow the manifold to expand and contract thermally while maintaining structural integrity and minimizing vibration. The flexible portions act as shock absorbers, reducing the transmission of vibrational forces that would otherwise cause fatigue in rigid connections.
2Reliability
If flexible hoses are used to connect fuel lines, then vibration and fatigue are reduced, but effectiveness in high temperature applications deteriorates
Solution Approach 1:
The fuel distribution manifold utilizes composite construction combining rigid thermally-stable materials for the main structure with flexible elements made from high-temperature resistant materials. This composite approach allows the system to withstand high combustor temperatures while the flexible portions provide vibration damping and fatigue resistance. The rigid sections maintain structural integrity at high temperatures, while the flexible bellows and expandable segments accommodate thermal movement.
3Productivity
If fuel lines are shut off for staged combustion, then engine efficiency is improved, but stagnant fuel causes coking
Solution Approach 1:
The patent implements a continuous fuel circulation system where fuel that would otherwise stagnate in shut-off lines during staged combustion is continuously pumped through the entire manifold. This ensures that all fuel lines, including those not currently delivering fuel to combustors, remain filled with moving fuel that is continuously cooled and prevented from degrading. The circulation system maintains continuous useful action of fuel flow, preventing coking while allowing staged combustion to improve engine efficiency.
Solution Approach 2:
A fuel circulation pump acts as an intermediary device that actively moves fuel through all manifold lines regardless of whether they are currently active for combustion. This intermediary pumping action ensures continuous fuel movement through potentially stagnant lines, preventing coking by maintaining fuel flow and cooling. The pump mediates between the staged combustion requirement (shutting off certain lines) and the need to prevent coking (maintaining fuel flow).
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 manages thermal expansion and contraction, reduces vibration and fatigue, and maintains fuel lines cool, preventing coking, while providing a means to detect leaks and improve engine efficiency through staged combustion.
Implementation Method 1
The sealing tube includes a resilient section in the form of a bellows or similar structure for accommodating axial expansion and contraction of the sealing tube as the combustor casing thermally expands and contracts during engine operation
Implementation Method 2
maintaining all of the fuel lines in the manifold assembly relatively cool, even when one or more of the fuel lines is shut-off
Data Source
AI summary
A fuel distribution manifold system for a gas turbine engine is disclosed that includes a plurality of interconnected manifold segments, each manifold segment extending between a pair of fittings, each manifold segment including at least one fuel transfer tube and a sealing tube that surrounds the at least one fuel transfer tube, wherein opposed end portions of the at least one fuel transfer tube are dynamically connected to the fittings and opposed end portions of the sealing tube are statically connected to the fittings.