Gas Turbine Rotor Blade Radially Inward Cooling Passage Design

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Solution Overview

Problem

Conventional rotor blades in gas turbine systems have limitations in cooling the radially inward portions of the airfoil trailing edge due to inadequate heat absorption through trailing edge passages.

Innovation Solution

The rotor blade design includes a platform with a radially inner surface and a shank portion that defines a shank pocket, an airfoil extending radially outwardly, and cooling passages that extend from the shank pocket to the airfoil, with outlets positioned radially inwardly from the trailing edge apertures, ensuring comprehensive cooling of the airfoil and platform.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional trailing edge passages are used to cool the rotor blade, then the trailing edge cooling is improved, but the radially inward portions of the airfoil trailing edge remain inadequately cooled

Engineering Contradiction:

Improvetrailing edge temperatureVSAvoidcooling coverage

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The cooling system is segmented into multiple independent cooling passages: trailing edge passages for cooling the trailing edge region, and radially inward cooling passages extending from the shank pocket to cool the radially inward portions of the airfoil. This segmentation allows each passage to target specific regions that were previously inadequately cooled by conventional single-path designs.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cooling passages extend in multiple spatial dimensions: trailing edge passages extend through the trailing edge thickness, while radially inward passages extend from the shank pocket radially outward into the airfoil. This multi-dimensional cooling approach ensures comprehensive coverage of all critical regions including the radially inward portions that were previously hot spots.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If cooling passages are extended radially inwardly to cool all portions of the airfoil, then cooling coverage is improved, but the complexity of the cooling circuit increases

Engineering Contradiction:

Improvecooling coverageVSAvoidcooling circuit complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Multiple cooling functions are merged into an integrated cooling circuit system. The trailing edge passages and radially inward passages are connected through the shank pocket, allowing a single cooling medium flow path to serve multiple cooling zones. This merging reduces the need for separate independent cooling systems while maintaining comprehensive cooling coverage.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The shank pocket serves multiple functions: it acts as a structural support element, defines the inlet for radially inward cooling passages, and provides a connection point for trailing edge passages. This multi-functionality reduces the number of separate components needed, thereby reducing overall system complexity while achieving comprehensive cooling.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of manufacture

If cooling passages are positioned radially outwardly to simplify the cooling circuit, then manufacturing complexity is reduced, but the radially inward portions of the airfoil are not adequately cooled

Engineering Contradiction:

Improvecooling passage manufacturingVSAvoidradially inward airfoil temperature

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

Different regions of the airfoil are cooled by dedicated cooling passages optimized for their specific thermal requirements. Radially inward passages target the radially inward portions with higher heat loads, while trailing edge passages address the trailing edge region. This local quality approach ensures each region receives appropriate cooling without requiring excessive complexity in the overall system.

Inventive Principle:

Principle #3Local quality

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 effectively cools the airfoil and platform by directing cooling air through passages that extend radially inwardly from the trailing edge apertures, enhancing the cooling efficiency and service life of the rotor blades in high-temperature environments.

Implementation Method 1

The cooling medium flowing through the plurality of trailing edge passages absorb heat from the portions of the airfoil proximate to the trailing edge, thereby cooling the trailing edge

Methodology Applied

Scientific EffectHeat absorption: Absorption (physical)

Data Source

PatentEP3249162B1Rotor blade and corresponding gas turbine system

Publication Date: 2021.08.18 GENERAL ELECTRIC CO

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AI summary

The present disclosure is directed to a rotor blade (100) for a gas turbine system (10). The rotor blade (100) includes a platform (102) having a radially inner surface (104) and a radially outer surface (106). A shank portion (116) extends radially inwardly from the radially inner surface (104) of the platform (102). The shank portion (116) and the platform (102) collectively define a shank pocket (120). An airfoil (126) extends radially outwardly from the radially outer surface (106) of the platform (102). The shank portion (116), the platform (102), and the airfoil (126) collectively define a cooling passage (148) extending from a cooling passage inlet (150) defined by the shank portion (116) or the platform (102) and directly coupled to the shank pocket (120) through the platform (102) to a cooling passage outlet (152) defined by the airfoil (126).