Guide to the types of power compressors: centrifugal VS axial flow

In the large family of power compressors, centrifugal compressors and axial compressors occupy the core position. Both of them belong to turbine compressors, but their working principles and structural characteristics are significantly different. In this paper, Turbo-Tech starts from the basic concepts to help you build an overall understanding of these two important devices.

1. What is a power compressor?

Power compressor is also called speed compressor. Its core working principle is that the high-speed rotating impeller does work on the gas, converting mechanical energy into kinetic energy of the gas, and then converting the kinetic energy into pressure energy through the diffuser. The characteristics of power compressor include large output flow, continuous stability, compact structure and low operation and maintenance cost.

Second, the two branches of the power compressor

According to the flow direction of gas in the impeller, power compressors are divided into two categories.

Centrifugal compressor: gas flows in radial direction. The gas is sucked in from the center of the impeller, thrown out in the radial direction after the impeller rotates at high speed, and the energy conversion is completed in the diffuser.

Axial compressor: gas flows in the axial direction. The gas flows axially through the channels with alternating moving blades and static blades, and is gradually pressurized by the lifting force of the blades.

Third, the core differences between the two

The different flow direction determines the fundamental difference in structure and performance between the two compressors: the single-stage pressure ratio of centrifugal compressor is large; The single-stage pressure ratio of axial compressor is small but the efficiency is high.

From the structural point of view, the flow passage of centrifugal compressor is relatively simple and the manufacturing cost is moderate; Axial-flow compressor has a large number of blades and complex shapes, and its manufacturing accuracy and cost are higher. From the point of view of operation and maintenance, the centrifugal compressor has strong adaptability to the change of working conditions; The energy-efficient operation range of axial compressor is relatively narrow.

Fourth, common ground

Although there are differences, as two branches of turbine compressors, they also have something in common: they both belong to speed compressors and rely on impellers to do work on gas; Both are suitable for industrial scenes with large flow and continuous operation; Both need precise dynamic balance and bearing support system; Load adjustment can be realized by frequency conversion or inlet guide vane adjustment.

V. How to choose

Knowing the difference between them is the basis of making a correct choice. In the following article, we will deeply analyze the respective characteristics and application scenarios of centrifugal and axial compressors from the perspectives of principle, structure, performance and application, so as to provide a more perfect reference for your selection.