Turbine Casing Alignment Using Laser Measurement

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Solution Overview

Problem

Current turbine assembly methods require temporary assembly and disassembly of casings to achieve accurate positional adjustment of stationary components, which increases the assembly time and complexity due to deformation and thermal expansion issues.

Innovation Solution

A method involving the measurement of positional information on specific portions of the casing in predetermined disassembly states to perform alignment without temporary assembly, utilizing deformation data to adjust the stationary components accurately.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If temporary assembly of casing is performed to obtain accurate inner diameter difference data, then manufacturing precision of stationary component positioning is improved, but loss of time increases due to repeated assembly and disassembly operations

Engineering Contradiction:
Improvepositioning accuracy of stationary componentsVSAvoidassembly time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The invention uses laser measurement technology to create a digital copy of the casing's inner diameter at multiple positions and heights. This optical measurement copy replaces the need for physical temporary assembly, allowing accurate acquisition of casing deformation data without actually assembling the casing. The measurement data is then used to calculate positioning adjustments for stationary components, achieving the same precision goal without the time-consuming assembly-disassembly cycle.

Inventive Principle:
Principle #26Copying

2Reliability

If thermal shrinking method is used for bolt fastening to prevent leakage, then reliability of sealing is improved, but loss of time increases due to sequential heating and cooling of multiple bolts

Engineering Contradiction:
Improvesealing reliabilityVSAvoidfastening time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention performs laser measurement of the casing's inner diameter before the thermal shrinking fastening process begins. By acquiring the casing deformation data in advance, the positioning adjustments for stationary components can be calculated and applied beforehand. This eliminates the need to wait for the time-consuming sequential heating and cooling of multiple bolts during fastening, as the positioning is already optimized based on pre-measured deformation data.

Inventive Principle:
Principle #10Preliminary action

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 allows for highly accurate positional adjustment of stationary components without the need for temporary casing assembly, reducing the assembly time and operational complexity while maintaining the required accuracy.

Implementation Method 1

positional information on a plurality of specific portions set on an outer surface of the casing is measured using a laser measuring instrument

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

measured using a laser measuring instrument

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

the bolts are temporarily heated to be expanded, and the nuts are engaged with the expanded bolts. After this, the bolts are cooled to press the nuts against the flanges

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 4

the bolts are cooled to press the nuts against the flanges

Methodology Applied
Scientific EffectThermal contraction: Thermal Contraction

Data Source

PatentEP3324005B1Turbine assembly method
Publication Date: 2020.06.17 MITSUBISHI HITACHIPOWER SYST LTD
  • EP3324005B1 patent drawingFigure 1~2
  • EP3324005B1 patent drawingFigure 3~5
  • EP3324005B1 patent drawingFigure 6

AI summary

A turbine assembly method includes a positional information measurement process in which positional information on a plurality of specific portions (51) set on an outer surface of a casing (1, 2) is measured in a state before releasing of bolt fastening of the casing (1, 2) at a time of disassembly of the turbine and in a predetermined disassembly state after the releasing of the bolt fastening, and an alignment process in which positional adjustment of a stationary component (6) with respect to the casing is made based on the measurement results of the positional information on the specific portions (51) in the positional information measurement process.