Fin-Pin Flow Guide for Transition Piece Cooling

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Solution Overview

Problem

The existing cooling systems for gas turbines, such as those using Thermal Barrier Coatings (TBC) or diffusion bonding, fail to effectively manage the high temperatures in transition pieces, leading to inefficiencies and increased maintenance, as they either compromise engine performance or result in hot spots due to stagnated cooling air.

Innovation Solution

A transition piece design incorporating an inner and outer structure with fin-pin flow guides that redirect and redistribute cooling air, with the fin-pin flow guides slanted relative to the center line and arranged at various portions to enhance airflow and prevent stagnation, thereby improving cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling air is supplied between the inner transition piece and outer transition piece through conventional holes, then cooling is provided, but flow stagnation occurs around the exit portion and hot spots form

Engineering Contradiction:

Improvecooling efficiencyVSAvoidflow stagnation and hot spot formation

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The flow guide structure is segmented into multiple fins distributed around the transition piece, with each fin creating localized flow guidance zones. This segmentation allows cooling air to be redirected systematically throughout the flow passage, preventing stagnation in specific areas while maintaining overall cooling efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention introduces a radial dimension to the flow guidance by extending fins from the inner transition piece surface into the flow passage. This transforms the conventional axial flow pattern into a three-dimensional flow structure that actively redirects cooling air around the exit portion, eliminating dead zones and hot spots.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Temperature

If a flow sleeve is used for cooling the transition piece, then cooling is improved, but combustor pressure drop increases and engine performance lowers

Engineering Contradiction:

Improvecooling performanceVSAvoidcombustor pressure drop

Core Design Contradiction:

TemperatureVSStress or pressure

Solution Approach 1:

The invention extracts the flow guidance function from a separate flow sleeve component and integrates it directly into the inner transition piece structure through fins. This eliminates the need for a dedicated flow sleeve, reducing the number of components and minimizing pressure drop while maintaining effective cooling air redirection.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The flow guidance features are merged with the inner transition piece structure itself, combining the structural component with the flow control function. This integration reduces the overall pressure drop compared to using a separate flow sleeve, while still achieving effective cooling air distribution.

Inventive Principle:

Principle #5Merging (Combining)

3Stress or pressure

If diffusion bonding or transient liquid phase bonding is used, then air leakage is reduced and pressure drop impact is reduced, but cooling performance is much lower than pure effusion cooling

Engineering Contradiction:

Improvepressure drop and air leakageVSAvoidcooling performance

Core Design Contradiction:

Stress or pressureVSTemperature

Solution Approach 1:

The invention applies effusion cooling holes strategically at locations where cooling performance is most critical, while using diffusion bonding or transient liquid phase bonding in other areas to minimize air leakage. This localized application of different cooling methods optimizes both cooling performance and pressure drop characteristics.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The fin structure acts as an intermediary element that enhances the effectiveness of reduced effusion cooling by redirecting and concentrating cooling air flow to critical heat zones. This mediator structure compensates for the lower cooling intensity from reduced effusion holes while maintaining acceptable pressure drop levels.

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

This design enhances cooling efficiency by preventing flow stagnation and maintaining high turbine inlet temperatures, reducing hot spots, and minimizing the impact on engine pressure drop, thus improving overall gas turbine performance.

Implementation Method 1

an outlet fin-pin flow guide disposed in the flow passage and located closer to the outlet than the inlet, wherein the outlet fin-pin flow guide is slanted with respect to a center line representing an imaginary line between an inlet center of the inlet and an outlet center of the outlet

Methodology Applied

Scientific EffectFlow redirection:

Data Source

PatentUS10890328B2Fin-pin flow guide for efficient transition piece cooling

Publication Date: 2021.01.12 DOOSAN HEAVY IND & CONSTR CO LTD

AI summary

A transition piece can include: an inner transition piece including an inlet and an outlet; an outer transition piece surrounding the inner transition piece with a flow passage; an outlet fin-pin flow guide disposed on the inner transition piece and located closer to the outlet than the inlet; a first bottom fin disposed at a bottom portion of the inner transition piece; and a second bottom fin disposed at the bottom portion of the inner transition piece, wherein the first bottom fin and the second bottom fin are arranged to be inclined to each other at an acute angle.