Write out the relationship between the power, flow, head and speed of centrifugal pump shaft (proportional law)
The law of similitude is applied to the same vane pump at different speeds, the ratio of flow, lift, power and speed:Q1/Q2 = n1/n2H1/H2 = (n1/n2) ^2N1/N2 = (n1/n2) ^3Q, H, N respectively indicate the flow, lift, power, subscript 1 relative to the speed of 1 physical quantity, subscript 2 relative to the speed of 2 of the physical quantity.
The large flow pump used in a small volume, will bring speed decreased, the low speed can meet the general requirements of the pump operation, the running speed of more than 20HZ, because of the need for cooling water pump motor, speed is too small, the heat dissipation capability of motor fan will be very small, easy to cause the motor cooling down, the motor burned.The law of similitude is applied to the same vane pump at different speeds, the ratio of flow, lift, power and speed:
Where H is the head of unit m, Q flow, unit m3/h, ETA for the efficiency of.P pump for shaft power, KW. is the shaft power P= P gQH/1000 ETA pump (kw), the P =1000Kg/m3, g=9.8The unit of specific gravity is Kg/m3, the unit of flow is m3/h, and the unit of lift is m, 1Kg=9.8 Newton
Shaft power = flow * lift * 9.81 x medium weight /3600 * pump efficiencyFlow unit: cubic / hour,Lift unit: MP=2.73HQ/,
