Turbine Transition Duct Modified Trailing Edge

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Solution Overview

Problem

Current transition ducts in turbine systems suffer from high aerodynamic losses, leading to non-uniform flow and high unsteady mixing losses, which result in increased cycle fatigue and thermal loads on turbine section buckets, reducing their durability and system efficiency.

Innovation Solution

A transition duct assembly with a plurality of transition ducts arranged in an annular array, featuring a modified aerodynamic contour at the trailing edge, which includes a pressure side, suction side, and a tangentially and radially offset outlet, reducing the need for first stage nozzles and minimizing mixing losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional transition ducts are used to shift hot gas flow radially or tangentially, then first stage nozzles can be eliminated, but aerodynamic losses and pressure losses increase significantly

Engineering Contradiction:

Improveelimination of first stage nozzlesVSAvoidaerodynamic losses and pressure losses

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The patent modifies the geometric parameters of the transition duct, specifically the outlet position and contour shape. By adjusting these parameters, the duct achieves efficient flow shifting while minimizing aerodynamic losses, resolving the contradiction between eliminating nozzles and maintaining energy efficiency.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs curved surfaces and optimized contours in the transition duct design. The curved outlet and optimized passage geometry reduce flow separation and wake formation, thereby reducing aerodynamic losses while maintaining the ability to eliminate first stage nozzles.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Device complexity

If conventional transition duct geometry is used, then flow shifting is achieved, but wakes and non-uniform flow increase downstream

Engineering Contradiction:

Improveflow shifting capabilityVSAvoidflow uniformity downstream

Core Design Contradiction:

Device complexityVSStability of the object's composition

Solution Approach 1:

The patent optimizes the outlet position parameters (radial and tangential offsets) and contour shape to control wake formation. These parameter changes ensure uniform flow distribution downstream while maintaining effective flow shifting, thus resolving the contradiction between flow shifting capability and downstream flow uniformity.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies different geometric characteristics to different portions of the transition duct. The outlet region has specific contour features designed to minimize wake formation, while other portions maintain flow shifting capability. This local optimization ensures uniform downstream flow without compromising flow shifting effectiveness.

Inventive Principle:

Principle #3Local quality

3Device complexity

If conventional transition ducts are used, then hot gas flow is shifted, but high cycle fatigue loads and thermal loads on buckets increase

Engineering Contradiction:

Improveflow direction controlVSAvoidbucket durability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent modifies the transition duct outlet parameters to reduce flow non-uniformity and wake formation. By optimizing these parameters, the flow impinging on the buckets becomes more uniform, reducing cyclic loading and thermal gradients, thus improving bucket durability while maintaining flow direction control capability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The curved outlet contour and optimized geometry reduce flow separation and wake formation, leading to more uniform flow distribution on the buckets. This reduces cyclic stresses and thermal loads, thereby improving bucket reliability while maintaining effective flow shifting.

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 modified aerodynamic contour of the transition duct assembly enhances efficiency by reducing aerodynamic losses and wake formation, resulting in more uniform flow and reduced high cycle fatigue and thermal loads on turbine section buckets, thereby improving system performance and bucket durability.

Implementation Method 1

The aerodynamic structure includes a pressure side, a suction side, and a trailing edge, the trailing edge having a modified aerodynamic contour

Methodology Applied

Scientific EffectAerodynamic contour modification: Aerofoil

Data Source

PatentUS9458732B2Transition duct assembly with modified trailing edge in turbine system

Publication Date: 2016.10.04 GE INFRASTRUCTURE TECH LLC

AI summary

Transition duct assemblies for turbine systems and turbomachines are provided. In one embodiment, a transition duct assembly includes a plurality of transition ducts disposed in a generally annular array and comprising a first transition duct and a second transition duct. Each of the plurality of transition ducts includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of each transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct assembly further includes an aerodynamic structure defined by the passages of the first transition duct and the second transition duct. The aerodynamic structure includes a pressure side, a suction side, and a trailing edge, the trailing edge having a modified aerodynamic contour.