Turbomachine Gland Seal Alignment via Inflatable Bellows
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Solution Overview
Problem
The alignment of gland seals in hydrogen cooled electric generators is critical for preventing hydrogen leakage and rotor vibration, but existing methods struggle to accurately determine and adjust the alignment due to the tight radial clearance and sagging rotor, leading to potential wear and shutdowns.
Innovation Solution
A method utilizing a pressure bellows to secure and align the gland seal relative to the rotor's instantaneous centerline, ensuring parallelism between the gland seal and rotor surfaces, allowing for precise adjustment of the gland seal bracket to maintain effective sealing and prevent wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the gland seal is aligned to the theoretical machine centerline, then the alignment is simple to establish, but the radial gap becomes inconsistent due to rotor sag causing uneven sealing pressure
Solution Approach 1:
The method performs preliminary measurement of the rotor's instantaneous centerline orientation using dial indicators before finalizing the gland seal alignment. This preliminary action captures the actual rotor position including sag effects, allowing the alignment procedure to compensate for rotor deflection and achieve consistent radial gaps without excessive complexity
Solution Approach 2:
The invention changes the reference parameter from the theoretical machine centerline to the instantaneous rotor centerline. By measuring and using the actual rotor position parameters (including sag-induced angular deviation) as the alignment reference, the method achieves consistent radial gaps that accommodate the rotor's actual operating position
2Reliability
If the radial gap between gland seal and rotor is reduced to improve sealing, then sealing effectiveness improves, but the risk of rotor contact and wear increases
Solution Approach 1:
The method ensures uniform local quality of the radial gap around the entire circumference of the gland seal. By aligning to the instantaneous rotor centerline and using precise measurement techniques, the procedure achieves consistent gap dimensions at all locations, preventing localized contact points that would cause wear while maintaining tight overall clearance for effective sealing
Solution Approach 2:
The alignment procedure uses feedback from dial indicator measurements to verify and adjust the gland seal positioning. By continuously monitoring radial gap dimensions during alignment and making adjustments based on measured values, the method ensures the gap remains within the optimal range that provides both effective sealing and prevents rotor contact
3Ease of operation
If the gland seal is misaligned due to rotor sag, then alignment procedure is simpler, but hydrogen leakage and rotor vibration occur
Solution Approach 1:
The method introduces dial indicators as intermediary measurement tools between the rotor and the alignment procedure. These indicators serve as mediators that capture the instantaneous rotor centerline position, allowing the alignment process to account for rotor sag without significantly increasing operational complexity. The intermediaries translate the complex rotor position into measurable alignment parameters
Solution Approach 2:
The procedure performs preliminary measurement and documentation of the rotor's instantaneous centerline orientation before final gland seal installation. This preliminary action captures sag effects and other position variations, enabling the alignment team to compensate for these factors during assembly and prevent hydrogen leakage and vibration issues
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
This approach ensures consistent radial gap and effective sealing, reducing the risk of hydrogen leakage and rotor vibration, thereby enhancing the operational reliability and longevity of the generator.
Implementation Method 1
A method utilizing a pressure bellows to secure and align the gland seal relative to the rotor's instantaneous centerline
Data Source
AI summary
A method of determining an alignment of a floating seal for a turbo machine, including establishing a reference surface on a rotor of the turbomachine that is essentially perpendicular to an instantaneous centerline of the rotor, establishing a control surface that radially aligns a floating seal member that surrounds the rotor, providing an inflatable member arranged between a stationary portion of the turbomachine and a surface of the floating seal, inflating the inflatable member such that the inflatable member urges the floating seal firmly against the control surface, measuring an axial distance between the floating seal and the reference surface at a plurality of locations, determining a parallelism between the facing surfaces of the floating seal and the rotor based upon the plurality of measured axial distances, comparing the determined parallelism with a predetermined threshold, and adjusting an orientation of the control surface based upon the comparison.