Rotating-Machine Casing Support With a Thermal Deformation Groove
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Solution Overview
Problem
In rotary machines like steam turbines and gas turbines, thermal deformations cause vertical displacement differences between built-in components and the rotor, leading to shaft vibration and performance degradation due to contact with seal fins or excessive clearance.
Innovation Solution
A rotary-machine casing support structure with a built-in component supported by the casing, a protrusion portion protruding laterally outside the casing, and a support portion to reduce vertical displacement differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the casing is supported by a protrusion portion on a support interface surface of the casing support, then the casing can be stably supported, but thermal deformation causes vertical displacement difference between built-in components and rotor leading to shaft vibration and performance degradation
Solution Approach 1:
A groove portion is introduced as an intermediary element between the protrusion portion and the support interface surface. The groove portion allows thermal deformation to occur within its depth while maintaining support functionality, thereby mediating between the need for stable support and the reality of thermal expansion. This resolves the contradiction by providing a buffer zone that absorbs dimensional changes without transmitting them to the built-in components.
Solution Approach 2:
The support structure parameters are changed by introducing a groove portion with specific depth and dimensions. This parameter modification allows the support to accommodate thermal deformation through the groove depth while maintaining overall support stability. The groove depth is specifically designed to match the maximum thermal deformation amount, creating a parameter-based solution that resolves the displacement issue.
2Stability of the object's composition
If the casing is rigidly supported to prevent movement, then support stability is improved, but thermal deformation cannot be accommodated causing contact between casing and seal fins
Solution Approach 1:
The groove portion serves as a mediator that allows controlled movement within the support structure. Instead of rigid connection, the groove provides a compliant interface that accommodates thermal expansion while preventing uncontrolled movement. This intermediary structure eliminates harmful contact with seal fins while maintaining adequate support stability.
Solution Approach 2:
The groove portion provides beforehand cushioning by pre-accommodating the expected thermal deformation within its depth. This prior cushioning capacity prevents the casing from moving beyond the groove depth and contacting seal fins, thereby preventing harmful effects before they occur.
3Reliability
If the support structure allows thermal deformation accommodation, then vertical displacement difference is reduced, but support stability may be compromised
Solution Approach 1:
The groove depth parameter is specifically designed to match the maximum thermal deformation amount. This parameter optimization allows the support to accommodate exactly the required deformation while maintaining stability for smaller variations. The width and other dimensions are also optimized to balance deformation accommodation with support stability.
Solution Approach 2:
The groove portion acts as a controlled intermediary that permits deformation within defined boundaries. It provides a buffer zone that allows necessary movement while preventing excessive displacement that would compromise stability. This mediator approach resolves the contradiction by enabling controlled flexibility within stable boundaries.
Data Source
AI summary
According to one embodiment, the present invention provides a rotating-machine casing support structure including: a casing; a built-in component that is disposed inside an interior space of the casing at a lateral side of a rotor and that is supported by the casing; a protruding part that is provided so as to protrude laterally outside of the casing from a side of the casing; and a support part that supports the protruding part laterally outside of the casing.