Hollow Diffuser Vane Jets for Centrifugal Compressor Stability

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Solution Overview

Problem

Centrifugal compressors face issues with increased energy consumption due to high temperature and gas specific volume, airflow mixing losses, and reduced stable operating range due to airflow angle variations and low-speed areas in diffuser vanes, leading to stall and surge.

Innovation Solution

A compressor structure with a diffuser vane featuring a hollow design and gas supplement holes on the suction surface forms a jet flow to eliminate low-speed and low-energy areas, reducing airflow mixing losses and improving aerodynamic efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a vaned diffuser is used to improve aerodynamic performance at design point, then the aerodynamic efficiency is improved, but the stable operating range is reduced due to stall and surge when operating conditions deviate from design point

Engineering Contradiction:
Improveaerodynamic efficiencyVSAvoidstable operating range
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The diffuser vane is designed to rotate about its own axis as the impeller rotates, changing the orientation of the vane surface relative to the incoming airflow. This dynamic adjustment allows the diffuser to adapt to varying inlet airflow angles, preventing airflow separation and maintaining stable operation across a wider range of operating conditions while preserving design-point efficiency

Inventive Principle:
Principle #15Dynamics

2Use of energy by moving object

If gas supplement is introduced to reduce intake air temperature and gas specific volume, then energy consumption is reduced, but airflow mixing loss increases due to difference in magnitude and direction of airflow speed

Engineering Contradiction:
Improveenergy consumptionVSAvoidairflow mixing loss
Core Design Contradiction:
Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The diffuser vane acts as an intermediary that guides and mixes the gas supplement stream with the main airflow in a controlled manner. By positioning the gas supplement holes on the suction surface and using the diffuser vane's geometry, the patent achieves gradual mixing that reduces turbulence and mixing losses while still achieving the desired temperature and specific volume reduction

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enhances aerodynamic efficiency and widens the operating range of the compressor by minimizing airflow separation and friction losses, while maintaining performance at the design point.

Implementation Method 1

the gas supplement holes are configured to form a jet flow on the suction surface to blow off a low-speed and low-energy area formed on the suction surface

Methodology Applied
Scientific EffectJet flow: Jet

Implementation Method 2

The pore portion is provided in a diffuser that converts the velocity energy of the gas into pressure energy

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP3623639B1Compressor structure and compressor
Publication Date: 2025.07.02 GREE ELECTRIC APPLIANCES WUHAN
  • EP3623639B1 patent drawingFigure 1~3

AI summary

The present application discloses a diffuser vane, a compressor structure and a compressor. The diffuser vane includes a vane body, wherein a cavity is formed inside the vane body, and a gas supplement hole is formed on the vane body. The present application may form a jet flow on a suction surface of the diffuser vane by way of gas supplement by the diffuser vane having a hollow structure as well as the gas supplement hole in the back thereof, so as to blow off a low-speed and low-energy area formed by the suction surface, and reduce an airflow mixing loss brought by gas supplement, thereby further improving the aerodynamic efficiency of the centrifugal compressor and enabling to widen the operating range of the compressor whilst improving aerodynamic performance of the compressor at the design-point.