Introduction to common pump terms (2) – efficiency + motor

power speed
1. Effective Power: Also known as output power. It refers to the energy obtained by the
liquid flowing through the water pump in a unit time from the water
pump .

Pe=ρ G Q H/1000 (KW)

ρ——Density of liquid delivered by pump(kg/m3)
γ——Weight of liquid delivered by pump(N/m3)
     Q——Pump flow (m3/s)
     H——Pump head(m)
     g——Acceleration of gravity (m/s2).

2.Efficiency
Refers to the percentage of the ratio of the effective power of the pump to the shaft power, expressed by η. It is impossible for all shaft power to be transferred to the liquid, and there is energy loss in the water pump. Therefore, the effective power of the pump is always less than the shaft power. Efficiency marks the effective degree of energy conversion of water pump, and is an important technical and economic index of water pump.

η =Pe/P×100%

3. Shaft power
Also known as input power. Refers to the power obtained by the pump shaft from the power machine, which is denoted by P.

PShaft power =Pe/η=ρgQH/1000/η (KW)

4. Matching power
Refers to the power of the power machine matched with the water pump, which is represented by P.

P(Matching Power)≥(1.1-1.2)PShaft power

5.Rotation Speed
Refers to the number of revolutions per minute of the impeller of the water pump, which is represented by n. Is the unit r/min.


Post time: Dec-29-2023