Gas Turbine Stator Vane Combustor Outlet Configuration

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The reduction of the axial gap between the first-stage stator vane and the combustor side wall in gas turbines leads to high-temperature gas flow due to pressure differences, necessitating increased cooling medium supply, which decreases efficiency.

Innovation Solution

The gas turbine design includes specific configurations such as angled combustor outlets and controlled protrusions of the stator vane surfaces to minimize the axial gap and reduce turbulence, ensuring the first-stage stator vane is efficiently cooled with a reduced cooling medium flow rate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the axial gap between the first-stage stator vane and the combustor side wall is reduced, then the cooling medium supply amount is reduced, but high-temperature gas flow occurs through the axial gap due to pressure difference

Engineering Contradiction:

Improvecooling medium supply amountVSAvoidhigh-temperature gas flow through axial gap

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The combustor outlet is divided into multiple segments (first combustor outlet and second combustor outlet) with different orientations. The first combustor outlet is oriented toward the suction surface side while the second combustor outlet is oriented toward the pressure surface side, allowing independent control of gas flow directions to prevent high-temperature gas intrusion through the axial gap

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the combustor outlet are given different local qualities through varied orientation angles. The first combustor outlet has a first orientation angle directed toward the suction surface, while the second combustor outlet has a second orientation angle directed toward the pressure surface, creating localized flow control that prevents high-temperature gas flow through the axial gap while maintaining efficient cooling

Inventive Principle:

Principle #3Local quality

2Loss of energy

If the first-stage stator vane is arranged close to the downstream end of the transition piece, then the inflow of combustion gas is suppressed, but the direct collision of high-temperature combustion gas against the leading edge is reduced requiring more cooling air

Engineering Contradiction:

Improveloss due to inflow of combustion gasVSAvoidcooling air

Core Design Contradiction:

Loss of energyVSQuantity of substance

Solution Approach 1:

The combustor outlets are designed with dynamic flow control through varied orientation angles. The first combustor outlet directs flow toward the suction surface at a first orientation angle, while the second combustor outlet directs flow toward the pressure surface at a second orientation angle, creating a dynamic balance that suppresses combustion gas inflow loss while preventing direct high-temperature gas collision with the leading edge

Inventive Principle:

Principle #15Dynamics

3Loss of energy

If the inner surface of the side wall and the outer surface of the first-stage stator vane are smoothly connected, then the turbulence is reduced, but the axial gap configuration must be precisely controlled to prevent high-temperature gas flow

Engineering Contradiction:

Improveturbulence lossVSAvoidaxial gap configuration precision

Core Design Contradiction:

Loss of energyVSManufacturing precision

Solution Approach 1:

The combustor outlets are designed with curved surfaces that smoothly connect to the first-stage stator vane. The inner surface of the side wall and the outer surface of the first-stage stator vane are formed with continuous curvature, eliminating sharp edges and corners that would generate turbulence, while the curved geometry naturally maintains the axial gap configuration to prevent high-temperature gas flow

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

This configuration effectively suppresses high-temperature gas flow through the axial gaps, reducing the need for cooling medium and maintaining turbine efficiency.

Implementation Method 1

a flow of the high-temperature combustion gas via the axial gap may occur due to a pressure difference between a pressure-surface side (concave side) and a suction-surface side (convex side) of the first-stage stator vane

Methodology Applied

Scientific EffectPressure difference: Pressure Gradient

Data Source

PatentUS11280203B2Gas turbine including first-stage stator vanes

Publication Date: 2022.03.22 MITSUBISHI POWER LTD

AI summary

A gas turbine includes a plurality of first-stage stator vanes arranged in a circumferential direction, the first-stage stator vanes each including a vane surface having a pressure surface and a suction surface, a first combustor disposed on a suction surface side of one of the first-stage stator vanes, the first combustor having a first combustor outlet which includes a first side wall portion extending along a radial direction, and a second combustor disposed on a pressure surface side of the one of the first-stage stator vanes and adjacent to the first combustor in the circumferential direction. The one of the first-stage stator vanes satisfies 0.05≤Δy/P≤0.25, where Δy is a protruding amount of the suction surface from the inner wall surface of the first side wall portion to the circumferential direction, and P is an arrangement pitch of the first-stage stator vanes in the circumferential direction.