Performance curve problem
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Can this performance curve help us find out what the efficiency of the pump is?
In this picture, why are there three curves? What do the decimals behind each curve represent? 0.37 0.55 0.75
The three pictures from top to bottom are the lift shaft power efficiency (including NPSH)?
0.37 0.55 0.75 is the motor power. Three powers correspond to three lifts. The same flow rate and different lifts will lead to different efficiencies.
This post was last posted by 3983596_FPPZ edited on 2018-9-23 09:00 The first picture is the flow-head relationship, the second picture is the flow-shaft power relationship, the left side of the third picture is the flow-NPSH relationship, and the right side is the flow-efficiency relationship. There are four flow units: Cubic meters per hour, liters per minute, imperial gallons per minute (IM GPM), US gallons per minute (US GPM), there are two lift units: Meters and feet (ft), there are two units of shaft power: Horsepower (hp) and kilowatt, there are two units of NPSH: meters and feet
The three curves are curves with different performance parameters obtained by cutting the outer diameter of the impeller, reducing the speed, or replacing the impeller. However, the maximum flow points of the three curves are all 75 L/min. Therefore, it is speculated that the other two performance parameters are not obtained by cutting the impeller or reducing the speed, but by replacing the impeller. Otherwise, the curves are not drawn rigorously or are drawn subjectively.