Gas Turbine Nozzle Maintenance Sled Access

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Solution Overview

Problem

Conventional methods for maintaining gas turbine nozzles are time-consuming and costly due to the difficulty in accessing and handling nozzles within the turbine housing, especially when they are positioned below the horizontal joint surface, leading to inconsistent seal placement and increased mechanical wear.

Innovation Solution

A nozzle maintenance apparatus that includes a nozzle engagement sled with a locking member and a towing system, allowing for the in-situ installation and removal of nozzles within the gas turbine casing while the rotor is in place, using a sled that can move along a slot in the casing and a towing system to raise and lower the nozzle for easier access and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If nozzles are positioned below the horizontal joint surface to reduce mechanical wear, then nozzle longevity is improved, but accessibility for maintenance deteriorates

Engineering Contradiction:
Improvenozzle service lifeVSAvoidnozzle accessibility
Core Design Contradiction:
Duration of action of stationary objectVSEase of operation

Solution Approach 1:

A sled apparatus serves as an intermediary tool to access nozzles below the horizontal joint surface. The sled includes a locking member that engages with the nozzle and a towing system with cables that extend above the joint surface, allowing maintenance personnel to access and manipulate nozzles in difficult-to-reach locations without direct access to the nozzle itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The maintenance approach transitions from vertical access (directly above the nozzle) to horizontal access (along the slot at the horizontal joint surface). The sled travels horizontally along the slot to reach nozzles positioned below the joint surface, changing the dimension of access from axial to radial.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If individual nozzles are accessed and maintained separately, then maintenance precision is improved, but maintenance time increases

Engineering Contradiction:
Improveseal placement consistencyVSAvoidmaintenance duration
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The sled apparatus can engage multiple nozzles simultaneously through multiple locking members, allowing maintenance personnel to service several nozzles in sequence or parallel without removing the sled. This combines multiple maintenance operations into a single setup, reducing the overall maintenance time while maintaining precision through the consistent positioning provided by the sled.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sled is positioned and locked onto the nozzle before maintenance operations begin. This preliminary positioning action establishes a fixed reference point that ensures consistent seal placement and alignment throughout the maintenance process, eliminating the need for repeated measurements and adjustments.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If conventional rigging methods are used to access nozzles, then equipment complexity is minimized, but maintenance cost increases

Engineering Contradiction:
Improvemaintenance equipmentVSAvoidmaintenance cost
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

The maintenance system is segmented into modular components: the sled body, locking members, towing system with cables, and pulleys. This segmentation allows for targeted replacement and maintenance of individual components without replacing the entire system, reducing long-term costs while maintaining manageable complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sled apparatus serves multiple functions: it provides positioning, locking, towing, and support for nozzle maintenance. This multi-functionality consolidates what would otherwise require multiple separate tools and equipment, reducing overall equipment complexity and maintenance costs by eliminating redundant systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3351342B1Nozzle maintenance apparatus and method
Publication Date: 2020.07.22 GENERAL ELECTRIC CO
  • EP3351342B1 patent drawingFigure 1
  • EP3351342B1 patent drawingFigure 2
  • EP3351342B1 patent drawingFigure 3

AI summary

Various embodiments include apparatuses (30) for performing maintenance on a gas turbine (GT) nozzle (20), along with related methods. One apparatus (30) can include: a nozzle engagement sled (32) for releasably engaging the nozzle (20), the nozzle engagement sled (32) including: a sled body (40); a locking member (34) coupled with the sled body (40), the locking member (34) sized to complement a slot (36) in the nozzle (20); a sled slot (48) within a side of the sled body (40), the sled slot (48) for engaging a rail (56) within the GT (10); and at least one wheel (58) for transporting the sled body (40) within the GT (10).