Seal Segment Reinforcement for Flutter Control in Rotary Machines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In rotary machines, swirling flows can cause pressure fluctuations and fluttering in high-pressure side plates, which can compromise sealing characteristics when rigidity is added to suppress fluttering.
Innovation Solution
A seal segment design with a high-pressure side plate that includes a reinforcing portion only on the front side in the rotational direction, where fluttering occurs most, maintaining sealing performance without affecting sealing characteristics, using either a thick plate portion, rib structure, or bent plate portion to adjust and increase rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If rigidity imparting means is provided on the high-pressure side plate to suppress fluttering, then fluttering is suppressed, but contact of the high-pressure side plate with the seal body is hindered, affecting sealing characteristics
Solution Approach 1:
The patent applies local quality by providing the reinforcing portion only in the front region of the high-pressure side plate where fluttering easily occurs, rather than uniformly across the entire plate. This localized reinforcement suppresses fluttering in the critical area while leaving other regions flexible enough to maintain contact with the seal body, thus preserving sealing characteristics.
2Stability of the object's composition
If the high-pressure side plate is made more rigid to suppress fluttering in high-speed swirling flow, then fluttering is suppressed, but the sealing performance of the thin plate seal piece deteriorates
Solution Approach 1:
The reinforcing portion is strategically placed only in the front region of the high-pressure side plate where fluttering easily occurs due to swirling flow, rather than making the entire plate rigid. This localized approach suppresses fluttering in the critical area while maintaining flexibility in other regions to ensure proper contact with the seal body and preserve sealing performance.
Data Source
AI summary
A seal segment (11) includes a seal body having a plurality of laminated thin plate seal pieces (20), and a high-pressure side plate (23). The high-pressure side plate (23) includes an outer diameter side edge portion (23b) which is an outer edge portion in the radial direction (Dr) and extends in a circular are shape in the circumferential direction (Dc), an inner diameter side edge portion (23c) which is an inner edge portion in a radial direction (Dr) and extends in a circular arc shape in the circumferential direction (Dc), and a front edge portion (23d) which is an edge portion on a front side in the rotational direction (Bc). The high-pressure side plate (23) further includes a reinforcing portion (40) only in a region of the high-pressure side plate (23) on the front side in the rotational direction (Bc).