What happens if the outlet of a centrifugal compressor is fully closed for a short period of time and then reopened?
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Under normal operation, the outlet of a centrifugal compressor is equipped with a two-position valve. What will happen if it suddenly closes and then opens again after a short period of time (with the entire process taking about 10 seconds)?
The outlet pressure and flow rate will fluctuate significantly; the anti-surge valve will open fully, and this should not cause a shutdown or any production accidents
Stop the machine – the inlet and outlet valves usually come equipped with position indication interlocks; as soon as the relevant signal is received, the interlock activates immediately, otherwise surge will occur.
“Is the centrifugal compressor outlet a two-position valve? ”,“Turn off suddenly for a short time and then turn on again”? First, what do the two valves mean? Second, closing the outlet valve for a short period can cause surging; sudden overpressure can also lead to an interlocked shutdown. Does this phenomenon occur? Did the user pressure behind the machine drop suddenly? Are there any trend charts? Organize your questions – figure out exactly what happened, and it’s best to post them. If you ask questions based on your own understanding without clarifying them, it’s not suitable for discussion.
The outlet valve is closed for ten seconds; depending on the design of the pipeline and the operating parameters at that time, different situations may occur. The outlet valve closed for unknown reasons, and the compressor continued to send signals to open it. If the outlet pressure exceeds the pressure of the pipeline safety valve during this period, the safety valve will open ； If the surge line of the pipeline is reached during this period, the anti-surge valve will activate ； If the safety valve does not activate within ten seconds, the valve will open again and the compressor will operate normally. If the outlet valve remains closed for an extended period, the compressor will shut down automatically, but it will not trip.
Obviously, it’s surge; for the next steps, we need to analyze each specific issue individually
If it occurs during startup or shutdown, 10 seconds is generally considered normal; however, when the unit is operating normally, this could lead to surge