Multi-Wall Turbomachine Casing Alignment for Blade Clearance Control
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Solution Overview
Problem
During turbomachine operation, the inner and outer walls of a multi-wall casing move relative to each other, leading to eccentricity and misalignment of axes, which increases variability in clearance and risks rub conditions between rotary blades and the inner wall, reducing efficiency and increasing the risk of damage.
Innovation Solution
A casing alignment system with alignment positioners, including mechanical springs, fluid-driven, and electric-driven adjusters, biases the inner wall to compensate for undesirable movement, aligning the central axes of the inner and outer walls by opposing the relative movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the inner and outer walls of the multi-wall casing are allowed to move relative to each other during turbomachine operation, then the casing can accommodate operational changes and thermal expansion, but this results in eccentricity and misalignment of axes between the inner and outer walls, increasing clearance variability and reducing turbomachine efficiency
Solution Approach 1:
The patent applies dynamics by making the inner wall position adjustable through alignment positioners that can dynamically compensate for relative movement between the inner and outer walls. The positioners include adjustable mechanisms that allow the inner wall to be repositioned to maintain proper alignment with the outer wall during operation, resolving the contradiction between adaptability and alignment precision.
2Manufacturing precision
If alignment positioners are added to maintain proper alignment between inner and outer walls, then clearance variability is reduced and turbomachine efficiency is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent applies segmentation by dividing the alignment system into multiple independent alignment positioners distributed around the casing. Each positioner independently adjusts the inner wall at its specific location, allowing the complex alignment task to be broken down into simpler, modular units that can be manufactured and adjusted separately, thereby managing device complexity while maintaining alignment precision.
3Manufacturing precision
If the inner wall is biased by alignment positioners to compensate for relative movement, then eccentricity-induced clearance variability is reduced, but additional forces are applied to the inner wall that may affect structural integrity
Solution Approach 1:
The patent applies local quality by positioning the alignment positioners at specific locations around the inner wall where they apply biasing forces only where needed to maintain alignment. The positioners are strategically placed to compensate for known movement patterns without applying excessive or unnecessary forces to the entire inner wall structure, thus maintaining clearance uniformity while preserving structural integrity.
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 alignment system effectively maintains proper alignment between the inner and outer walls, reducing eccentricity-induced clearance variability and minimizing the risk of blade rub conditions, thereby enhancing turbomachine efficiency and safety.
Implementation Method 1
The alignment positioner may comprise a spring, bellows, crest or wave spring
Implementation Method 2
a force displacement device or a constant force device, e.g. a pneumatic piston
Data Source
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AI summary
A system includes a casing alignment system (16) configured to align an inner wall (106) with an outer wall (104) of a multi-wall casing (102) of a turbomachine (10) having a rotor. The casing alignment system (16) includes a first alignment positioner (100) configured to bias a first lip (152) of the inner wall (106) in a direction of rotation (180) of the rotor disposed within the multi-wall casing (102). The alignment positioner (100) may include a spring (174), a fluid-driven alignment positioner (100, 170, 320), an electric-driven alignment positioner (100, 170, 300), or a combination thereof. The alignment positioner (100) may be configured to bias the first lip (152) within a first recess (160) adjacent a first flanged coupling (128) between first and second wall sections (122, 124) of the outer wall (104).