Seeking advice from experts: issues with compressor operation
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The compressor operating point is near the surge line; can increasing the speed move it away from the surge line? During surge, the inlet flow rate is insufficient; increasing the speed improves the inlet suction capacity, so shouldn’t surge be more likely to occur?
Which brand of compressor are you using? Increasing the speed doesn’t seem to be commonly used on compressors, does it?
If the speed is increased while the outlet flow rate remains unchanged, it will not move away from the surge zone; only by reducing the speed is it possible to do so, provided that the outlet pressure is decreased
Surge is an abnormal operating condition of centrifugal compressors; it is associated with a certain flow rate at a specific outlet pressure. The surge curve is a characteristic curve of centrifugal compressors, and it is determined by the manufacturer prior to commissioning. As indicated by the poster, the air inflation volume is insufficient. Increasing the rotation speed can raise the outlet pressure as well as the flow rate; however, with an increase in flow rate, the actual amount of air inflated also increases. To increase the flow rate, it is also necessary to add additional inlet guide vanes. When the flow rate rises to a certain level, the pressure may decrease, as the work done by the compressor remains constant; with a larger volume of gas, the outlet pressure drops accordingly. A decrease in pressure leads to a decrease in the flow rate, thereby keeping it away from the surge curve. PS: It doesn’t matter even if the operation is near the surge curve – as long as the compressor functions properly, surge will not occur. The above are merely my humble opinions; I need experts to provide the correct answers. This post was last edited by brainandrain on 2009-2-23 17:21]
By increasing the speed when there is still room for acceleration in the compressor, and while keeping the outlet pressure constant, the compressor’s operating point moves away from the surge line, which is more conducive to stable operation of the compressor.
Personally, I believe increasing the speed can keep one away from the stall line. During surge, the inlet flow rate is insufficient; increasing the speed enhances the inlet suction capacity, causing the compressor’s operating curve to shift to the right and thereby improving the safety of the unit. General regulation first involves increasing the inlet valve or reducing the unit’s outlet pressure to move away from the surge line.
It is recommended that you reduce the load and increase the speed.