Centrifugal Compressor Surge Flowrate

This is called the surge flow rate – it represents the flow rate corresponding to the operating point where the maximum allowable pressure and minimum allowable flow rate are reached. In fact, operation at this point is not permitted; protection measures are put in place to prevent the compressor from reaching this condition. Therefore, at a certain distance from this point, various parameters such as current, pressure, and flow rate are monitored as a basis for regulation. That’s how kinetic energy devices work, including centrifugal fans. General current protection is relatively effective and economical. The flow range between this point and the design point is its theoretical adjustment range. The actual adjustment range is smaller than this; as mentioned earlier, surge protection needs to be installed at a certain distance from this point. It’s not possible to wait until the most dangerous point is reached before taking action – by then it will already be too late. Its value is determined once the fan is fixed, but the surge point for each performance curve varies, for example, depending on the speed or the temperature.

It should be translated as surge flow rate. Surge refers to the phenomena of overcurrent and overvoltage that occur in motors under abnormal conditions; when applied to compressors, it is known as surge. This phenomenon tends to occur when the inlet flow rate is insufficient due to reduced load or when the backpressure in the piping system increases. In such situations, the airflow moves back and forth periodically inside the compressor, causing severe vibration in the compressor