When simulating a pump in Aspen Plus, the results show that the effective NPSH is negative
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The result is as shown in the image; it’s unclear what the cause is
Aspen Plus file
Sorry, the version is too high and it can’t be opened. Are there any errors in the simulation results? It’s likely that there is air in the pump inlet, which has caused cavitation; try lowering the inlet temperature
This does happen sometimes. Under the corresponding operating conditions, the pump may experience cavitation. It is recommended to increase the inlet pressure or lower the temperature of the inlet liquid.
It’s because the net positive suction head of your unit is too low. Actual handling method: 1. Reduce the temperature of the incoming liquid ； 2. Increase the pressure of the inlet liquid (including nitrogen pressurization or raising the pump inlet equipment) ； 3. Dig a hole and place the pump underground. When using ASPEN for simulation, you can simply set the inlet pressure higher or reduce the inlet liquid temperature.
This post was last edited by xyq1983 on 2021-3-10 08:10. Such a simple calculation doesn’t really tell us anything; it’s simply the case that the pressure at the pump inlet is lower than the saturated vapor pressure. It only makes sense to perform calculations by including the height and back pressure as well. Otherwise, it’s meaningless, or one could specify the pipe diameter and static head in the pump’s calculation options