Gas Turbine Rotor Sealing Element with Axial Displacement
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Solution Overview
Problem
Existing sealing solutions for rotor discs require axial fixation to an inner edge portion, which limits axial displaceability due to thermal expansions and adjacent component arrangements, making it difficult to maintain a seal without bending stresses during assembly.
Innovation Solution
A sealing element with a retaining projection and fastening projection system that allows axial fixing without axial fixation to the inner edge portion, utilizing a conical circumferential surface as a sealing surface and interlocking hooks or T-shaped profiles for secure attachment, enabling axial and radial stability while allowing for thermal expansion compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sealing plate is fixed axially to the rotor disc at the inner edge portion, then the sealing plate is securely attached, but axial displaceability is limited due to thermal expansions and adjacent component arrangements
Solution Approach 1:
The sealing plate is divided into two functional zones: an inner edge portion that remains free for axial displacement, and an outer region with retaining projections that provide secure attachment. This segmentation allows different parts of the sealing plate to have different degrees of freedom, resolving the contradiction between secure attachment and axial displaceability.
Solution Approach 2:
The sealing plate transitions from a completely fixed design to a dynamic design where the inner edge portion can move axially to accommodate thermal expansion, while the outer region maintains secure attachment through retaining projections. This dynamic capability allows the sealing plate to adapt to changing operational conditions.
2Ease of manufacture
If the ring groove is arranged in the rotor disc with fixed axial position, then assembly is simplified, but thermal expansions cause displacement of the ring groove leading to seal failure
Solution Approach 1:
The sealing plate is designed with dynamic axial displaceability at the inner edge portion, allowing it to move and maintain seal integrity even when the ring groove position shifts due to thermal expansion. This dynamic adjustment prevents seal failure while maintaining the fixed ring groove arrangement for ease of manufacture.
Solution Approach 2:
The sealing plate's axial position parameter is made variable through the free inner edge portion design, allowing it to adjust its position in response to thermal expansion-induced groove displacement. This parameter change capability maintains seal integrity without requiring a more complex manufacturing process.
3Adaptability or versatility
If the sealing plate is allowed to move axially, then thermal expansion compensation is possible, but bending stresses occur during installation
Solution Approach 1:
The sealing plate is segmented into a free inner edge portion that handles axial movement for thermal expansion compensation, and a supported outer region with retaining projections that provide structural strength. This segmentation allows axial mobility where needed while maintaining strength to resist bending stresses during installation and operation.
Solution Approach 2:
The retaining projections act as intermediaries that connect the sealing plate to the rotor disc at the outer region, providing structural support and resistance to bending stresses. This intermediary support system allows the inner edge portion to move freely for thermal expansion compensation without compromising overall structural integrity.
Data Source
AI summary
A sealing element and a rotor of a gas turbine having at least one rotor disc and having an annular rotor component arranged adjacently to the rotor disc and having a plurality of sealing elements arranged distributed around the circumference. The sealing elements are fastened to the rotor disc at least in the axial direction. An inner edge portion of each of the sealing elements is adjacent to a sealing portion of the rotor component. In order to provide a seal between the sealing element and rotor component whilst at the same time enabling a relative axial displacement, a ring seal is arranged in a receiving space formed by the sealing element and rotor component.