Twisted Airfoil Diffuser Blades for Centrifugal Compressor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Centrifugal compressors face challenges in achieving a wide operating range while maintaining efficiency, as low solidity diffusers offer large flow ranges but at the expense of efficiency, and high solidity diffusers are more efficient but lack operating range.
Innovation Solution
An airfoil diffuser with twisted blades that vary in solidity from less than 1.0 at the hub plate to over 1.0 at the shroud, optimizing both operating range and efficiency by adjusting inlet blade angles and lean angles in a stacking direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If low solidity diffusers are used, then operating range is increased, but efficiency deteriorates
Solution Approach 1:
The diffuser blades are designed with varying solidity values across different radial locations. The hub region has lower solidity (less than 1.0) to maintain wide operating range, while the shroud region has higher solidity (greater than 1.0) to maintain high efficiency. This local differentiation resolves the contradiction by allowing each region to optimize for its specific function.
Solution Approach 2:
The invention transitions from a uniform solidity design to a three-dimensional variable solidity design. By varying the blade chord length in the radial direction (from hub to shroud), the solidity value changes continuously across the diffuser passage, enabling simultaneous optimization of operating range and efficiency in different spatial zones.
2Loss of energy
If high solidity diffusers are used, then efficiency is improved, but operating range deteriorates
Solution Approach 1:
The diffuser blades are designed with varying solidity values across different radial locations. The hub region has lower solidity (less than 1.0) to maintain wide operating range, while the shroud region has higher solidity (greater than 1.0) to maintain high efficiency. This local differentiation resolves the contradiction by allowing each region to optimize for its specific function.
3Ease of manufacture
If constant solidity blades are used, then manufacturing is simplified, but performance across operating range deteriorates
Solution Approach 1:
The diffuser blades transition from a static, uniform solidity design to a dynamic, variable solidity design. The blade geometry is specifically contoured to provide different solidity values at different radial positions, enabling the diffuser to adapt its performance characteristics across the operating range while maintaining manufacturability through precise geometric definition.
Data Source
AI summary
An airfoil diffuser for a centrifugal compressor formed by a diffuser passage area and a plurality of diffuser blades located within the diffuser passage area. The diffuser passage area is defined between a hub plate and a shroud of the centrifugal compressor. Each of the diffuser blades has a twisted configuration in a stacking direction as taken between the hub plate and an outer portion of the shroud located opposite to the hub plate. As a result of the twisted configuration, the diffuser blade inlet blade angle decreases from the hub plate to the outer portion of the shroud and solidity measurements at leading edges of the diffuser plates vary between a lower solidity value measured at the hub plate of less than 1.0 and a high solidity value measured at the outer portion of the shroud of no less than 1.0.