Centrifugal Compressor Impeller Blade Angle Distribution
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Solution Overview
Problem
Centrifugal compressors face limitations in expanding their operating range and improving efficiency due to unsuitable loading distribution and strength issues in the impeller, particularly at high circumferential velocities.
Innovation Solution
The blade angle distribution from the leading edge to the trailing edge of the impeller is optimized based on a loading distribution, with a focus on reducing blade loading between the leading edge and the throat position to increase the shroud side relative velocity, and incorporating a rake angle to enhance strength and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the blade loading is concentrated on the leading edge side to improve efficiency and expand operating range, then the loading distribution is optimized, but the strength of the impeller may be compromised at high circumferential velocities
Solution Approach 1:
The patent applies local quality by creating non-uniform blade loading distribution along the blade length. Specifically, the loading is concentrated on the leading edge side (upstream side) and the hub side (downstream side), while reducing loading in intermediate regions. This localized variation in loading characteristics optimizes flow control and efficiency without uniformly compromising impeller strength throughout the entire blade structure.
Solution Approach 2:
The patent changes the loading distribution parameter along the blade from a uniform or conventional distribution to a specifically designed non-uniform distribution. By adjusting the loading concentration ratio and its spatial distribution, the patent achieves improved operating range and efficiency while maintaining impeller strength through optimized parameter selection in different blade regions.
2Power
If the circumferential velocity of the impeller is increased to improve compression performance, then the pressure ratio increases, but the impeller strength becomes insufficient due to centrifugal forces
Solution Approach 1:
The patent addresses the strength limitation at high circumferential velocities by applying local quality to the blade loading distribution. By concentrating loading on specific regions (leading edge and hub side) and reducing it in other areas, the patent creates a non-uniform stress distribution that allows higher overall circumferential velocities while preventing excessive stress concentration that would compromise impeller strength.
3Productivity
If the blade loading distribution is optimized to suppress secondary flow and improve efficiency, then the operating range expands, but the design complexity increases
Solution Approach 1:
The patent implements local quality through a systematic blade loading distribution approach. By defining specific loading concentration regions (leading edge side and hub side) with clear spatial relationships, the patent achieves complex flow control objectives without requiring overly complicated blade geometries. The method provides a structured framework for achieving efficient flow management.
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 approach allows for a wider operating range, improved efficiency, and increased circumferential velocity, while suppressing surge occurrence and reducing fluid loss, thereby enhancing the overall performance of the centrifugal compressor.
Implementation Method 1
a centrifugal compressor provided with an impeller, which rotates at high speed and has a large circumferential velocity
Implementation Method 2
a blade angle distribution from a leading edge to a trailing edge of a blade provided in an impeller is determined based on a loading distribution of the blade
Data Source
AI summary
A centrifugal compressor provided with an impeller which is configured to have a plurality of blades arranged at a predetermined interval in a circumferential direction of a hub rotating together with a rotation shaft, in which a blade angle on a shroud side of the blade distributes to have a minimum value at a position between a leading edge of the blade and a midpoint of a camber line on the shroud side, and a maximum value at a position between the midpoint of the camber line on the shroud side and a trailing edge of the blade, and a blade angle of the blade on a hub side distributes so as to have a maximum value at a position between a leading edge and a midpoint of a camber line on the hub side.