Axial Turbomachine Compressor Brush Seal Wear Reduction
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Solution Overview
Problem
The existing axial turbomachine brush seals face premature wear due to pressure differences and create flow disturbances, reducing their service life and compressor efficiency.
Innovation Solution
An axial turbomachine compressor design featuring an annular sealing surface surrounding the brush seal, with bristles aligned to the internal flow envelope, and an axial brush seal integrated into the inner shroud, reducing wear and enhancing compactness by minimizing the radial thickness and depth of the inner shroud and rotor blades.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a downstream brush seal is used to prevent flux circulation between the inner shroud and rotor, then sealing effectiveness is improved, but the brush seal wears out quickly due to pressure differences pressing it against the rotor platform
Solution Approach 1:
The invention extracts the harmful pressure differential effect by introducing a pressure equalization channel that communicates the high-pressure region upstream of the stator with the low-pressure region downstream, thereby eliminating the force that presses the brush seal against the rotor platform and prevents premature wear
Solution Approach 2:
The invention introduces a pressure equalization channel as an intermediary element between the upstream and downstream regions of the stator. This channel acts as a mediator to balance pressures on both sides of the brush seal, preventing the pressure differential from causing excessive wear while maintaining sealing effectiveness
2Reliability
If multiple steps are created on the interior surface for downstream and upstream seals, then sealing is improved, but flow disturbance increases which affects compressor performance
Solution Approach 1:
The invention applies local quality by creating a localized pressure equalization channel only in the specific region where pressure differential causes wear, rather than modifying the entire interior surface with multiple steps. This localized approach maintains sealing effectiveness while minimizing flow disturbance
Solution Approach 2:
The invention transitions from a two-dimensional surface modification approach (multiple steps on interior surface) to a three-dimensional volumetric approach (pressure equalization channel). This dimensional change allows pressure balancing without creating disruptive surface steps that disturb the flow
3Reliability
If a downstream brush seal is added to ensure tightness, then sealing is improved, but an axial gap is added between stator and rotor vanes which reduces compactness
Solution Approach 1:
The invention merges the pressure equalization function with the existing brush seal structure by creating a pressure equalization channel that integrates with the stator geometry. This combination achieves both sealing effectiveness and pressure balancing without requiring separate components that would increase axial gap and reduce compactness
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to an axial turbomachine compressor comprising: a stator with an annular row of radially extending stator blades (32), an inner annular shell (36) disposed at the inner ends of the stator blades (32), and a downstream brush seal (40) disposed on the inner shell (36), which has a profile of revolution extending primarily axially. The brush seal includes bristles that extend primarily axially. The compressor also comprises a rotor having an annular sealing surface (42), generally cylindrical or frustoconical, disposed on the downstream side of the stator blades (32) and which cooperates with the brush seal (40) so as to provide a seal between the inner shell (36) and the rotor. The annular surface (42) surrounds the brush seal (40) such that the pressure downstream of the brush seal (40) tends to push it away from the annular surface (42).The brush seal wears less when in contact with the annular surface.