Knowledge

 

Centrifugal compressors are widely used in gas transmission, power generation, and chemical engineering, among other fields. The design of their blades is crucial to performance and efficiency. This article compiles the provided user information, references engineering principles and the latest research, to ensure the comprehensiveness and accuracy of the content.

 

1. In a centrifugal compressor, air flows radially from the impeller inlet (center) to the outlet.

As the radius increases, due to the centrifugal force and energy input, the tangential velocity and pressure gradually increase. To adapt to these changes, the blade shape must be adjusted:

a. Control the airflow angle to ensure smooth streamlines.

b. Reduce flow separation to avoid efficiency loss.

c. Maintain efficient momentum transfer to enhance overall performance.

 

2. Blade twist (aerodynamic optimization) from the root (close to the axis) to the tip.

The curvature and installation angle of the blade usually change. This "twist" is to adapt to the constantly changing direction of the relative velocity. The reasons include:

a. As the radius increases, the linear velocity of the blade increases.

b. The axial and radial velocity components of the airflow also change. This design helps maintain the optimal angle of attack (the angle at which the airflow enters the blade), thereby reducing energy loss and avoiding stall.

Studies show that blade twist is crucial for improving aerodynamic efficiency.

 

3. Different blade profiles with varying load distributions help to evenly distribute aerodynamic loads along the blade height.

a. This reduces structural stress and material fatigue.

b. It also reduces vibration and improves operational stability.

c. This leads to an extended equipment lifespan and reduced long-term fatigue damage.

 

4. In some designs, the impeller and diffuser are matched, and the blade profile of the impeller is optimized based on the inlet characteristics of the diffuser.

If the blade exit angle does not match the diffuser inlet, it may cause flow separation and reduce the pressure recovery efficiency. Research emphasizes the importance of matching, but there may be disputes in different designs, and adjustments need to be made according to specific applications.

 

5. The changes in blade profiles in multi-objective optimization design are usually aimed at achieving the following goals:

a. Improving aerodynamic efficiency and reducing energy loss.

b. Increasing pressure ratio and enhancing compression capacity.

c. Reducing tip leakage and secondary flow losses and optimizing internal flow.

d. Ensuring sufficient margin for anti-surge and anti-stall to guarantee operational stability.

 

Vigor has the professional 5 axle machining centers and the team to produce the high accurate impellers for centrifuge and centrifugal blower and turbocharger etc. If you have question or any impellers need to be developed, please feel free to contact us at info@castings-forging.com