On the surge problem of centrifugal compressors
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I would like to ask those who are passing by: is it only centrifugal compressors that experience surge? Is the only way to prevent surge to be by installing a surge line (similar to the return line in centrifugal pumps: connecting from the outlet to the inlet of the centrifugal pump to ensure that its flow rate remains at the rated operating point)? ) This is one method. Please explain. . . . :'(
Both pumps and fans can experience surge. Definition of surge: Periodic oscillations of the fluid in fluid machinery and its pipelines, which are mechanical vibrations that occur as a result of the fluid being periodically drawn in and discharged. For example, the surge phenomenon that can occur during the operation of a pump or compressor is as follows: when the flow rate drops to its minimum value, the outlet pressure suddenly falls, and the pressure inside the pipeline becomes higher than the outlet pressure. As a result, the fluid being transported flows back into the machine, until the outlet pressure rises again and the fluid is sent back out into the pipeline ； When the pressure in the pipe returns to its original level, the flow rate decreases again, causing the fluid in the pipe to flow backward, and this cycle repeats itself. Causes of surge: Surge occurs due to the characteristics of fluid machinery and pipelines; the larger the capacity of the pipeline system, the more severe the surge and the lower its frequency. Fluid machinery products are generally provided with pressure-flow characteristic curves, based on which the surge point, surge boundary line, or surge region can be determined. Surge in fluid machinery disrupts the regular flow of the medium inside the machine, generates mechanical noise, causes severe vibration of the working components, and accelerates the wear and damage of bearings and seals. Once surge causes resonance in the pipes, machinery, and their foundations, it can also lead to serious consequences. To prevent surge, the fluid machinery must be operated outside the surge region. In compressors, anti-surge control systems of the minimum flow type, flow-speed control type, or flow-pressure difference control type are commonly used. When multiple machines operate in series or parallel, they should each have their own anti-surge control device. Surge, as the name implies, is similar to asthma in humans; it involves periodic airflow and backflow in the fan. Axial flow fans are more prone to surge, and severe cases of surge can lead to fatigue and damage of the fan blades.
Does that mean that only centrifugal compressors experience surge? ? ?
As far as I know, axial flow fans also have the problem of surge
The hazards of surge in axial flow fans are much greater than those in centrifugal fans