Elliptical Sealing System for Rotary Machine Leakage Control
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Solution Overview
Problem
Rotary machines face inefficiencies due to fluid leakage across seals, which increases fuel costs and reduces performance, especially during transient operations where extra clearance is needed to prevent component damage from thermal expansion and contraction.
Innovation Solution
An elliptical sealing system with abradable coating and biasing members is used between the rotor and stator housing, featuring a retractable I-shaped packing ring and 'J'-type strips, allowing for minimal clearance and interference engagement to reduce leakage while maintaining component safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If extra clearance dimension is provided in the seal, then the likelihood of contact and damage between rotating and stationary components is reduced during transient operations, but the performance and efficiency of the seal and rotary machine deteriorate due to increased leakage flow
Solution Approach 1:
The seal clearance is made dynamic rather than fixed. During steady-state operation, the seal elements maintain minimal clearance for optimal sealing. During transient operations with thermal expansion, the seal elements can move radially to accommodate clearance changes without causing damage, thus dynamically adapting to different operational conditions
Solution Approach 2:
The seal design allows clearance parameters to change based on operational conditions. The biasing members enable the seal elements to adjust their position radially, changing the clearance dimension from a fixed value to a variable parameter that adapts to thermal expansion during transient operations while maintaining minimal clearance during steady-state operation
2Loss of energy
If smaller clearance dimension is used at the seal, then the performance and efficiency of the seal and rotary machine are improved by limiting leakage, but the likelihood of contact and damage between rotating and stationary components increases during transient operations
Solution Approach 1:
The seal clearance is made dynamic rather than fixed. During steady-state operation, the seal elements maintain minimal clearance for optimal sealing. During transient operations with thermal expansion, the seal elements can move radially to accommodate clearance changes without causing damage, thus dynamically adapting to different operational conditions
Solution Approach 2:
The biasing members (springs) provide beforehand cushioning by allowing the seal elements to move radially during transient operations. This cushioning effect prevents direct contact and damage between rotating and stationary components when thermal expansion occurs, while still maintaining effective sealing during normal operation
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 elliptical sealing system effectively minimizes fluid leakage, enhancing the efficiency of rotary machines by maintaining optimal clearance and preventing damage during both steady-state and transient operations.
Implementation Method 1
The sealing segments with the abradable coating thereon may be provided with a substantially elliptical shape
Implementation Method 2
A plurality of biasing members may be in communication with the sealing segments and the stator housing
Implementation Method 3
The sealing segments with the abradable coating thereon may be provided with a substantially elliptical shape
Data Source
Figure 1~3
AI summary
The present application provides an elliptical sealing system (140) for use with a rotor (120) and a stator housing (130) of a rotary machine (100). The elliptical sealing system (140) may include a number of sealing segments (260) with an abradable coating (170) thereon. The sealing segments (260) with the abradable coating (170) thereon may have a substantially elliptical shape (240). A number of biasing members (180) may be in communication with the sealing segments (260) and the stator housing (130).