Cross-Flame Duct Slip Joint and Cooling Chambers

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Solution Overview

Problem

Traditional cross-flame tubes in gas turbines are susceptible to thermal and mechanical stresses, leading to component fatigue and operational failures due to their flexible material design.

Innovation Solution

A cross-flame duct with a slip joint design and cooling chambers, maintained by standoffs and fluid ports, to prevent stress development and enhance flexibility and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional flexible metal hose design is used for cross-flame tubes, then assembly tolerances and differential thermal growth are accommodated, but thermal and mechanical stresses cause component fatigue and operational failures

Engineering Contradiction:

Improveaccommodation of assembly tolerances and differential thermal growthVSAvoidcomponent fatigue and operational failures

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The cross-flame tube is divided into multiple rigid sections (first cross-flame tube section, second cross-flame tube section) connected by a sliding joint. This segmentation allows each section to be structurally sound while the joint provides the necessary flexibility to accommodate thermal growth and assembly tolerances without subjecting the entire tube to damaging stresses.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The sliding joint introduces a dynamic element that allows relative movement between the rigid tube sections. This dynamic connection enables the cross-flame tube system to adapt to thermal expansion and contraction, as well as assembly variations, while maintaining structural integrity and avoiding the fatigue issues associated with continuously flexible hoses.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If flexible material is used for cross-flame tubes, then assembly tolerances are compensated, but thermal stresses lead to material loss due to overheating or burning

Engineering Contradiction:

Improvecompensation for assembly tolerancesVSAvoidthermal stresses and material loss

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The sliding joint acts as a cushioning mechanism that anticipates and absorbs thermal stresses before they can cause material damage. By allowing controlled movement between sections, the joint prevents stress accumulation that would otherwise lead to overheating and material loss in the tube walls.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The sliding joint serves as an intermediary element between the rigid tube sections, mediating the thermal stresses and allowing them to be dissipated through controlled movement rather than being transmitted directly to the tube material, thereby preventing overheating and material degradation.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

The solution maintains the cross-flame duct's flexibility during operation, reducing thermal and mechanical stresses, thereby extending its useful life and preventing material loss from overheating.

Implementation Method 1

The cooling chambers may be supplied with cooling fluids via one or more fluid ports extending through the outer sleeves enabling air to flow through the cooling chambers and into the combustors

Methodology Applied

Scientific EffectConvection cooling: Convection

Implementation Method 2

The first and second ducts include cooling chambers positioned between outer sleeves and inner housings and may be maintained with one or more standoffs to reduce thermal stress and gradients or prevent meaterial loss due to overheating or burning

Methodology Applied

Scientific EffectThermal gradient reduction: Temperature Gradient

Implementation Method 3

The cross-flame duct remains flexible during tubine operation due to the slip joint, thereby preventing damaging thermal and mechanical stresses from developing within the cross-flame duct

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3189277B1Cross ignition flame duct

Publication Date: 2020.04.15 SIEMENS AG

Figure 1A
Figure 1B
Figure 2A

AI summary

A cross-flame duct (100) for connecting adjacent combustors (1, 2) together in a gas turbine to guard against flameout conditions within the combustors (1, 2), whereby the cross-flame duct (100) may include first and second ducts (102, 106) forming a slip joint to prevent stress from developing within the cross-flame duct (100) is disclosed. The cross-flame duct (100) remains flexible during tubine operation due to the slip joint, thereby preventing damaging thermal and mechanical stresses from developing within the cross-flame duct (100) and enhacing the useful life of the cross-flame duct (100) and associated components. The first and second ducts (102, 106) may also include cooling chambers (138, 156, 174) positioned between outer sleeves (122, 140) and inner housings (128, 146) and maintained with one or more standoffs (134, 152, 170) to reduce thermal stress and gradients or prevent meaterial loss due to overheating or burning. The cooling chambers (138, 156, 174) may be supplied with cooling fluids via one or more fluid ports (176) extending through the outer sleeves (122, 140) enabling air to flow through the cooling chambers (1138, 156, 174) and into the combustors (1, 2).