Floating Rotor Seal Segments for Turbomachine Leakage Control
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Solution Overview
Problem
Leakage or backflow of compressed air or combustion gases in gas turbine engines affects engine component life and efficiency.
Innovation Solution
A sealing system with linear seal segments that use pressure delta to maintain a continuous seal between stationary components, utilizing a spring bias member like a wave spring to preload the segments, and are configured to seal axially or radially, preventing leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional sealing methods are used in turbomachines, then the structure is simple, but leakage occurs affecting engine component life and efficiency
Solution Approach 1:
The sealing system is divided into multiple independent linear seal segments that can move and seal independently. Each seal segment is a discrete component that operates autonomously, allowing the system to accommodate dimensional variations and thermal expansion while maintaining sealing effectiveness across the entire sealing surface.
Solution Approach 2:
The linear seal segments are designed to be movable rather than rigidly fixed, allowing them to dynamically adjust their position and shape in response to pressure differential changes, thermal expansion, and dimensional variations. This dynamic capability enables the sealing system to maintain effective seals under varying operating conditions without requiring complex rigid structures.
2Reliability
If rigid sealing structures are used, then manufacturing is easier, but thermal expansion and dimensional variations cause leakage
Solution Approach 1:
The seal segments utilize material properties that change with temperature, specifically thermal expansion coefficients, to accommodate dimensional variations. The segments are designed to expand or contract with thermal conditions, maintaining seal contact and effectiveness. This parameter-based adaptation eliminates the need for complex compensation mechanisms while ensuring continuous sealing.
Solution Approach 2:
The linear seal segments function as flexible elements that can deform to accommodate dimensional variations and thermal expansion. These segments act as thin, flexible barriers that maintain seal integrity without requiring rigid structural support, allowing them to flex and adapt to changing conditions while preventing leakage.
3Reliability
If multiple seal segments are used to prevent leakage, then sealing effectiveness improves, but the number of parts increases
Solution Approach 1:
Multiple linear seal segments are merged into a single integrated sealing system that functions as one cohesive unit. The segments are arranged in series along the sealing surface and work together to provide continuous sealing, with each segment contributing to the overall leakage prevention while maintaining individual independence in their sealing action.
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 sealing system effectively prevents leakage, enhancing engine component life and efficiency by maintaining a continuous seal during operation.
Implementation Method 1
utilizing a spring bias member like a wave spring to preload the segments
Implementation Method 2
the pressurized working fluid exerts a radially outward acting force with respect to a radial direction against the linear seal segment
Data Source
AI summary
A turbomachine comprises a nozzle segment including an inner shroud defining a bottom surface and a nozzle flange defining a forward side surface and an aft side surface. A floating rotor seal is coupled to the nozzle flange via a carrier flange. The carrier flange includes a forward wall and an aft wall. The nozzle flange is positioned between the forward and aft walls and a flowpath is defined therebetween. A seal pocket is defined in one of the forward wall or the aft wall and is in fluid communication with the flowpath. At least one linear seal segment is partially disposed within the seal pocket. The linear seal segment is configured to form a seal against the nozzle flange or the bottom surface in response to pressurization of the seal pocket via a working fluid in the flowpath.