What is surge limit in cetrifugal compressor?
Surge Limit is the Minimum Flow Point ( in the compressor characteristic curve ) below which the compressor operation become instable. If the flow-rate is reduced, the pressure developed by the compressor decreases. Then, the pressure in the discharge line becomes greater , and the gas flow back into the compressor. As soon as the pressure in the discharge line drops to below that developed by the compressor, the gas again flows in the discharge line. Then, the cycle repeats. The oscillating pressure and flow rate will cause audible vibrations and shocks, and could damage the compressor blades, seals, and other components. Therefore, the compressor requires an antisurge control system to limit the flow rate at a minimum point, safely away from the surge limit.