Segmented Face Seal Assembly for Large Rotor Turbomachines
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Solution Overview
Problem
Existing face seal assemblies in turbomachines with segmented rings face challenges in assembly due to interference with large rotor components, resulting in low rigidity and susceptibility to deformation, leading to premature wear and performance degradation.
Innovation Solution
A face seal assembly comprising a first and second segmented seal ring with flat-contact surfaces, where the second segmented seal ring is circumferentially offset from the joints of the first segmented seal ring, and coupled using coupling members to minimize axial steps and enhance rigidity, allowing for in-situ assembly on large-scale turbines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a continuous 360-degree stationary ring is used, then the rigidity is high, but it is difficult to assemble over large-sized rotors due to interference with rotor components
Solution Approach 1:
The continuous stationary ring is divided into two or more segmented rings that can be assembled separately and joined together using coupling members. This segmentation allows the rings to be installed over large-sized rotors without interference from rotor components, while the coupling members maintain the structural integrity and rigidity of the assembled ring.
2Ease of operation
If segmented rings are used, then assembly is easier, but axial steps are produced at the interface between segments
Solution Approach 1:
Coupling members are introduced as intermediary components that join the segmented rings together. These coupling members bridge the gaps between segments, eliminating axial steps at the interfaces and ensuring a flush, continuous sealing surface while maintaining the assembly advantages of segmented design.
3Ease of operation
If segmented rings are used, then assembly is easier, but the assembled ring has low rigidity and is susceptible to deformation
Solution Approach 1:
The coupling members are designed and positioned in advance to provide preliminary structural support and alignment for the segmented rings. This preliminary action ensures that the segments are properly positioned and supported before final assembly, preventing deformation and maintaining rigidity throughout operation.
4Ease of operation
If segmented rings are used, then assembly is easier, but the face seal assembly is susceptible to deformation leading to premature wear
Solution Approach 1:
The segmented design with properly positioned coupling members allows for controlled assembly while maintaining structural integrity. The segmentation enables precise positioning and alignment of each segment, reducing stress concentrations and preventing the deformation that leads to premature wear of the sealing surface.
Data Source
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AI summary
A turbomachine (36) and a method of assembling a face seal assembly (102) are disclosed. The turbomachine (36) includes a stator (39), a rotor (40), and a face seal assembly (102) including first and second segmented seal rings (114, 116). The first segmented seal ring (114) includes a plurality of joints (152) and a first flat- contact surface (160) and the second segmented seal ring (116) includes a plurality of segment ends (164) and a second flat-contact surface (166). The second segmented seal ring (116) is coupled to the first segmented seal ring (114) such that the second flat-contact surface (166) is in contact with the first flat-contact surface (160). The plurality of segment ends (164) is circumferentially offset from the plurality of joints (152). The first segmented seal ring (114) is slidably coupled to the stator (39) and defines a face seal clearance (104) between the rotor (40) and a seal bearing face (132).