Steam Turbine Seal Ring Support to Prevent Bending Deformation
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Solution Overview
Problem
In seal devices for rotary machines, the semi-arcuate seal ring can bend due to its own weight and back pressure, limiting radial displacement and potentially compromising sealing performance.
Innovation Solution
A seal device with a movable seal ring supported by first and second elastic members, where the second elastic member biases the seal ring outward in the radial direction, preventing deformation and bending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the seal ring is made semi-arcuate to match the rotor shape, then the seal ring can conform to the rotor outer periphery, but the seal ring bends and deforms outward due to its own weight and back pressure
Solution Approach 1:
The seal ring is divided into multiple arcuate segments that can independently displace radially. Each segment is supported by elastic members that allow independent movement, preventing bending deformation while maintaining the overall arcuate shape that conforms to the rotor outer periphery.
Solution Approach 2:
The seal ring transitions from a rigid fixed structure to a dynamic structure where individual segments can displace radially in response to pressure changes. This dynamic capability allows the seal ring to maintain its conformed shape while accommodating operational forces without bending deformation.
2Stability of the object's composition
If the seal ring is made rigid to maintain shape, then bending is reduced, but the seal ring cannot achieve desired radial displacement for sealing
Solution Approach 1:
The seal ring is segmented into multiple independent sections, each capable of radial displacement through elastic support. This segmentation allows the overall structure to maintain shape stability while individual segments achieve the necessary radial movement for effective sealing.
Solution Approach 2:
The seal ring uses flexible arcuate segments supported by elastic members (such as elastic plates or springs) that enable controlled radial displacement. This flexible construction maintains shape stability while allowing the required radial movement for sealing contact with the rotor.
3Length of moving object
If the seal ring is supported by elastic members, then radial displacement is enabled, but the seal ring may still bend due to back pressure
Solution Approach 1:
The seal ring is divided into multiple segments, each supported by its own elastic members. This segmentation distributes the back pressure loads across multiple independent support points, preventing bending deformation while maintaining radial displacement capability for each segment.
Solution Approach 2:
The elastic members are positioned and configured to provide counterbalancing support forces that counteract the bending effects of back pressure. This anti-weight approach maintains shape stability while allowing the seal ring to achieve necessary radial displacement for sealing.
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 solution effectively suppresses bending of the seal ring, thereby enhancing sealing performance by ensuring consistent radial displacement and preventing deformation.
Implementation Method 1
a first elastic member provided at each of end surfaces in a circumferential direction of the movable seal ring; and a second elastic member that is provided at an intermediate position in the circumferential direction of the movable seal ring
Data Source
AI summary
This seal device comprises: a movable seal ring arranged so as to be deformable in the radial direction, in a state of facing an outer peripheral surface of a rotor of a steam turbine capable of rotating around the axis; a first elastic member provided to each of end surfaces of the movable seal ring in the circumferential direction; and a second elastic member that is provided to an intermediate position in the circumferential direction of the movable seal ring and urges the movable seal ring outward in the radial direction.