initial data liquid

water temperature t =5^оС;

density of water ρ=999,99 kg/m³;

kinematic viscosity of water ν=0,0152 cm²/s;

Hydraulic calculation of pipeline

Pipe diameters are determined by the recommended a calculated rate of water movement in them. The calculated velocity is adopted in accordance with the Table

Pipe diameters, mm	Recommended the calculated velocity of water in the pipes, m/s
in the suction line	in the discharge line
≤ 250	0,7…1,0	0,8…2,0
300…800	0,8…1,5	1,0…3,0
> 800	1,2…2,0	1,5…4,0

Calculated pipe diameter suction line. The average velocity of the fluid

V=0,7…1,0 m/s,

d₁=(4Q)0.5/(π∙V)0.5=(4∙0.061)0.5/(π∙0.7)0.5=0.333

md₁=(4∙0.061)0.5/(π∙1)0.5=0.279 m

Estimate the diameter of the pipe, the pressure line

V=0,8…2,0

m/sd₂=(4∙0.061)0.5/(π∙0.8)0.5 =0.311

md₂=(4∙0.061)0.5/(π∙2)0.5 =0.197 m

where

Q =0,061m³/s – pump performance (specified flow rate);

Rated power at the pump shaft

NВ=ρ•g•Q•H•10-3/η=1000•9,81•0,061•53•10-3/0,7= 45,39 kW,

where g =9,81m/s² — acceleration of gravity;

H = 53 m – pump design head;

η - pump efficiency.Estimated nominal motor power

Nm=NВ/(ηc•ηm)=45,39/(0,96•0,92)=51,39 kW,

where ηc - Coupling efficiency;

ηm - motor efficiency.

Rated power of the motor mounting

Nmount=β•Nm= 1,2•51,39 = 61,67 kW,

where β=1,2 - power factor of safety for the pressure line pipe diameter 0,2 m.