Gas Turbine Blade Ring Outer Channel Thermal Stress Absorption
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Solution Overview
Problem
Conventional gas turbines experience thermal stress due to thermal elongation differences between the blade ring and the outer channel, leading to potential deformation and damage.
Innovation Solution
Incorporating a thermal stress absorbing portion between adjacent fixing portions in the outer channel, which is expandable and contractible in the circumferential direction, to absorb thermal elongation differences and reduce stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If an outer channel is provided in the blade ring for cooling, then the blade ring can be cooled effectively, but thermal stress occurs due to thermal elongation difference between the blade ring and the outer channel
Solution Approach 1:
The outer channel is divided into multiple sections: fixing portions that are rigidly fixed to the blade ring, and thermal stress absorbing portions that are expandable and contractible. This segmentation allows different parts of the channel to have different thermal behaviors, reducing overall thermal stress.
Solution Approach 2:
The thermal stress absorbing portion is designed with changed physical parameters (expandable and contractible structure) to accommodate thermal elongation differences. This parameter change allows the channel to dynamically adjust its dimensions in response to temperature variations, preventing stress accumulation.
2Stability of the object's composition
If the outer channel is rigidly fixed to the blade ring, then the channel structure is stable, but thermal stress causes deformation and damage
Solution Approach 1:
The outer channel is segmented into fixing portions (for stability) and thermal stress absorbing portions (for durability). This segmentation allows the structure to maintain stability where needed while accommodating thermal expansion elsewhere, preventing deformation and damage.
Solution Approach 2:
The thermal stress absorbing portion is designed in advance to cushion against thermal stress before it causes damage. The expandable and contractible structure acts as a buffer that absorbs thermal elongation differences, preventing stress concentration at the fixing portions.
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 solution effectively alleviates thermal stress, preventing deformation and damage, and stabilizes the performance of the gas turbine by allowing the thermal stress absorbing portion to expand and contract, thus maintaining clearance and operational efficiency.
Implementation Method 1
The cooling steam performs heat exchange by being flowed through the inner channel and cools the blade ring
Implementation Method 2
a thermal stress absorbing portion which is disposed between the fixing portions adjacent in the circumferential direction and is expandable and contractible in the circumferential direction
Data Source
AI summary
A gas turbine includes a blade ring which faces blades from the outer side in a radial direction perpendicular to a turbine shaft, and a channel provided in the blade ring 1 and through which a cooling medium is flowed. The channel includes an inner channel formed in the blade ring 1, and a tubular outer channel which is connected to the inner channel, is disposed in an outer portion of the blade ring 1, and extends in a circumferential direction of the blade ring 1. The outer channel includes a plurality of fixing portions fixed to the blade ring 1 and a thermal stress absorbing portion disposed between the fixing portions adjacent in the circumferential direction and expandable and contractible in the circumferential direction.