Flow Path Forming Plate Cooling Passage Design

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Solution Overview

Problem

Existing gas turbine technologies face challenges in efficiently cooling the gas path surface of flow path forming plates exposed to high-temperature combustion gas, leading to suboptimal performance and potential overheating.

Innovation Solution

The design incorporates a flow path forming plate with a first side passage and end surface blow-out passages, where the passage cross-sectional area of the end surface blow-out passages is smaller than the first side passage, allowing cooling air to flow through and perform convective cooling on the plate surface, reducing pressure loss and enhancing cooling efficiency without increasing airflow rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If cooling air flows through conventional passages with uniform cross-sectional area, then cooling coverage is provided, but pressure loss increases and cooling efficiency decreases

Engineering Contradiction:
Improvepressure lossVSAvoidcooling efficiency
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

The patent applies parameter changes by varying the cross-sectional area of cooling passages along their length. The first side passage has a larger cross-sectional area at the gas path surface end and a smaller area at the opposite end, creating a gradual area transition. The end surface blow-out passages have even smaller areas. This progressive area reduction optimizes the velocity distribution of cooling air, enhancing convective cooling at the gas path surface while controlling pressure loss through the gradual area change rather than abrupt transitions.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If the passage cross-sectional area of end surface blow-out passages is made smaller than the first side passage, then convective cooling efficiency on the gas path surface is enhanced, but the complexity of the passage geometry increases

Engineering Contradiction:
Improvecooling efficiencyVSAvoidpassage geometry complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating different cross-sectional areas in different regions of the cooling passage system. The first side passage has a larger cross-sectional area near the gas path surface to maximize cooling effectiveness at the hottest location, while the area gradually reduces toward the opposite end. The end surface blow-out passages have the smallest areas. This localized variation in passage geometry optimizes cooling where it is most needed while managing overall flow characteristics.

Inventive Principle:
Principle #3Local quality

3Temperature

If cooling air flow rate is increased to improve cooling effectiveness, then cooling efficiency improves, but pressure loss and energy consumption increase

Engineering Contradiction:
Improvecooling effectivenessVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by optimizing the cross-sectional area distribution of cooling passages to enhance cooling effectiveness without proportionally increasing flow rate. The varying area design creates favorable velocity profiles that improve convective heat transfer coefficients, allowing for reduced cooling air consumption while maintaining or improving cooling effectiveness. This geometric optimization reduces the energy penalty associated with cooling air extraction and compression.

Inventive Principle:
Principle #35Parameter changes

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 cools the gas path surface, reducing overheating and improving the operational efficiency of gas turbines by optimizing cooling airflow and pressure loss.

Implementation Method 1

allowing cooling air to flow through and perform convective cooling on the plate surface

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3388628B1Flow path forming plate, blade provided with same, gas turbine provided with same, and method for manufacturing flow path forming plate
Publication Date: 2020.09.23 MITSUBISHI HITACHIPOWER SYST LTD
  • EP3388628B1 patent drawingFigure 1
  • EP3388628B1 patent drawingFigure 2
  • EP3388628B1 patent drawingFigure 3

AI summary

Provided is a flow path forming plate having a gas path surface (64p) that comes in contact with combustion gas, end surfaces formed at peripheral edges of the gas path surface (64p), a first side passage (90i), and a plurality of end surface blow-out passages (71). The first side passage (90i) extends in a direction along a first end surface (62b) that is one of the end surfaces, and cooling air (Ac) flows through the first side passage (90i). A plurality of passage forming surfaces forming the first side passage (90i) includes a first forming surface (91) that faces an opposite-flow-path side (Dri) and extends gradually farther away from the gas path surface (64p) while extending toward the first end surface (62b). The end surface blow-out passages (71) open in the first forming surface (91) of the first side passage (90i) and in the first end surface (62b).