Segmented Stator Blade Ring Welding for Axial Compressor Thermal Control

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Solution Overview

Problem

Conventional stator blade rings in axial flow compressors face thermal deformation and strength reduction due to heat from electron-beam welding, leading to decreased compression efficiency and performance.

Innovation Solution

The stator blade ring design features arch-shaped connecting members welded to stator blade segments at specific lengths, reducing heat input and allowing for independent shape determination, with segments inserted into a guide groove to form a ring shape, minimizing thermal deformation and enhancing structural strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If electron-beam welding is performed over the entire circumference of the stator blade ring, then the stator blades and shrouds are joined together, but the stator blades and shrouds are subjected to great heat causing deformation

Engineering Contradiction:
Improvejoint strengthVSAvoidblade shape precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The stator blade ring is divided into multiple stator blade segments (e.g., 10-20 segments) arranged circumferentially. Each segment includes stator blades with their respective inner and outer shrouds. This segmentation allows welding to be performed on individual segments rather than the entire ring at once, reducing heat accumulation and thermal deformation while maintaining joint strength.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Welding is performed locally at the circumferential ends of each stator blade segment rather than over the entire circumference. The welding portions are positioned at the inner and outer shroud ends in the circumferential direction, applying heat only where needed to join segments while minimizing thermal exposure to the blade airfoils and maintaining manufacturing precision.

Inventive Principle:
Principle #3Local quality

2Strength

If electron-beam welding is performed over the entire circumference, then the stator blades and shrouds are joined, but the shrouds become wavy and are projected into or recessed from the chamber

Engineering Contradiction:
Improvestructural integrityVSAvoidshroud surface flatness
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

Dividing the stator blade ring into multiple segments allows each segment to be welded and positioned independently. This prevents the cumulative thermal distortion that occurs when welding the entire ring at once, maintaining shroud surface flatness and proper chamber alignment while ensuring structural integrity through multiple localized welds.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Welding is performed partially on each segment (at the circumferential ends) rather than excessively over the entire circumference. This partial welding approach provides sufficient structural integrity through the distributed welds while avoiding the excessive heat input that causes shroud warping and misalignment with the chamber.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If welding is performed over the entire circumference, then complete joining is achieved, but heat input causes thermal deformation disturbing air flow

Engineering Contradiction:
Improvejoining completenessVSAvoidcompression efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The stator blade ring is segmented into multiple sections with welding performed at the circumferential ends of each segment. This segmentation achieves complete joining through distributed welds while minimizing heat input to any single area, preventing thermal deformation of the blade airfoils and maintaining compression efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Welding is applied locally at the circumferential ends of stator blade segments rather than uniformly across the entire ring. This localized welding achieves reliable joining at the critical connection points while minimizing thermal exposure to the blade airfoils, preserving air flow quality and compression efficiency.

Inventive Principle:
Principle #3Local quality

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 design reduces thermal deformation, maintains compression performance, and improves structural strength, leading to enhanced efficiency and flexibility in axial flow compressors.

Implementation Method 1

The stator blade segments are welded to the connecting members at a portion of the length thereof in the circumferential direction

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP2172620B1Stator blade ring for an axial compressor
Publication Date: 2016.11.30 MITSUBISHI HITACHIPOWER SYST LTD
  • EP2172620B1 patent drawingFigure 1
  • EP2172620B1 patent drawingFigure 2~3
  • EP2172620B1 patent drawingFigure 4~5

AI summary

A stator blade ring is provided with which the possibilities of thermal deformation and a decrease in strength can be reduced, the shape flexibility can be ensured, and the compression performance can be improved. It includes stator blade segments (21) in each of which an inner shroud portion (31) and an outer shroud portion (29) divided corresponding to one stator blade (27) are provided at both ends of the stator blade (27) so as to be formed as a single part, and connecting members (23) that are formed of arch-shaped plates and are disposed on at least one of the inner shroud portions (31) and the outer shroud portions (29) of the stator blade segments (21) adjoining in a circumferential direction, on a side opposite to the stator blades (27). The stator blade segments (21) are welded to the connecting members (23) at a portion of the length thereof in the circumferential direction.