Turbine Casing Alignment Using Prediction Offset Values
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Solution Overview
Problem
The current top-on/top-off alignment procedure for turbine systems is time-consuming and inaccurate, leading to increased costs and potential efficiency losses due to misalignment of components during the servicing of turbines.
Innovation Solution
A method and system for aligning components within a turbine casing by measuring reference points on the horizontal joint flanges in both top-on and top-off positions, calculating a prediction offset value based on these measurements, and adjusting the component support positions to improve alignment relative to the rotor axis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the conventional top-on/top-off alignment procedure is used, then component alignment can be achieved, but the process is extremely time-consuming and requires multiple removals and reattachments of upper casings
Solution Approach 1:
The patent applies preliminary action by measuring and recording the positions of reference points on the lower casing in the top-off state before the upper casing is attached. These measurements are used to calculate predicted offset values that pre-compensate for the distortion that will occur when the upper casing is attached in the top-on state. This eliminates the need for iterative measurements and adjustments, significantly reducing alignment time while maintaining precision.
Solution Approach 2:
The patent creates a mathematical model (copy) of the lower casing's geometry and distortion characteristics by measuring reference points in the top-off state. This digital model is then used to predict and compensate for alignment offsets without requiring physical trial-and-error adjustments, reducing both time and material waste.
2Measurement precision
If the upper casing is removed and reattached multiple times during alignment procedures, then alignment measurements can be taken, but additional displacement or distortion occurs among previously-aligned components
Solution Approach 1:
The patent performs all necessary measurements in the top-off state before attaching the upper casing, capturing the true positions of reference points without the distortion introduced by the upper casing weight. The calculated offset values pre-compensate for expected distortion, eliminating the need for repeated removals and reattachments that cause additional displacement.
Solution Approach 2:
The patent applies preliminary anti-action by calculating and applying offset values that pre-counteract the expected distortion caused by attaching the upper casing. This anticipatory compensation prevents alignment errors before they occur, maintaining both measurement precision and alignment stability without requiring iterative corrections.
3Loss of information
If conventional alignment procedures are used, then component positions can be measured, but the process is inaccurate due to not considering the complete top-on situation
Solution Approach 1:
The patent creates a universal measurement system that captures comprehensive geometric information about the lower casing in the top-off state. This multi-functional approach simultaneously measures reference points at multiple locations, records the complete spatial configuration, and generates offset values that account for all aspects of top-on distortion, providing complete alignment information for accurate positioning.
Solution Approach 2:
The patent creates a complete digital copy of the lower casing's geometry and expected distortion characteristics by measuring multiple reference points. This comprehensive model captures all relevant spatial information, enabling accurate prediction of component positions in the top-on state without losing any critical alignment data.
Data Source
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AI summary
A method and system for aligning a component within a turbine casing (100), and a related turbine casing, are disclosed. In a top-on position, a location of an optical target (140) and another, vertically spaced optical target (148) on the joint flange are measured. After removing at least the upper casing (106), the optical targets' locations are measured again, and the locations of a pair of reference points on an upper surface of the horizontal joint flange are measured. A prediction offset value is calculated for the component support position in the top-on position based on the locations. The prediction offset value may include a vertical adjustment based, in part, on a translation of a triangular spatial relationship of a number of the reference points and/or a tilt angle, a horizontal adjustment, and a horizontal joint flange surface distortion adjustment. The component support position is adjusted by the prediction offset value to improve alignment.