1、 Calculation formula of shaft power of centrifugal pump

flow × lift × nine point eight one × Medium specific gravity ÷ 3600 ÷ pump efficiency

Flow unit: m3 / h,

Lift unit: M

P=2.73HQ/ η,

Where h is the head in M, q is the flow in m3 / h, η Is the efficiency of the pump. P is the shaft power, in kW. That is, the shaft power P of the pump= ρ gQH/1000 η (kw), where ρ= 1000Kg/m3,g=9.8

The unit of specific gravity is kg / m3, the unit of flow is m3 / h, the unit of head is m, 1kg = 9.8 Newton

Then p = specific gravity * flow * head * 9.8 N / kg

=Kg / m3 * m3 / h * m * 9.8 N / kg

=9.8 N * m / 3600 s

=Newton * m / 367 seconds

=Watt / 367

The above derivation is the origin of the unit. The above formula is the calculation of water power. The shaft power is divided by the efficiency

Let shaft power be ne, motor power be p, and K be coefficient (reciprocal of efficiency)

Motor power P = ne * k (K has different values when ne is different, see the table below)

Ne≤22 K=1.25

twenty-two

fifty-five

2、 Calculation formula of shaft power of slurry pump

Flow Q m3 / h

Lift h m H2O

Efficiency n%

Slurry density a kg / m3

Shaft power n kw

N=H*Q*A*g/(n*3600)

Transmission efficiency and safety factor shall also be considered for motor power. Generally, the direct connection is 1, the belt is 0.96, and the safety factor is 1.2

3、 Pump efficiency and its calculation formula

It refers to the ratio of the effective power of the pump to the shaft power. η= Pe/P

Pump power usually refers to the input power, that is, the power transmitted by the prime mover to the pump shaft, so it is also called shaft power, expressed by P.

Effective power is the product of pump head, mass flow and gravity acceleration.

Pe= ρ G QH (W) or PE= γ QH/1000 (KW)

ρ： Density of liquid delivered by pump (kg / m3)

γ： Gravity of liquid delivered by pump γ=ρ g (N/ m3)

g: Gravitational acceleration (M / s)

Mass flow QM= ρ Q (T / h or kg / s)

4、 Introduction to efficiency of water pump

What is pump efficiency? How about the formula?

Answer: it refers to the ratio of the effective power of the pump to the shaft power. η= Pe/P

Pump power usually refers to the input power, that is, the power transmitted by the prime mover to the pump shaft, so it is also called shaft power, expressed by P.

Effective power is the product of pump head, mass flow and gravity acceleration.

Pe= ρ G QH w or PE= γ QH/1000 (KW)

ρ： Density of liquid delivered by pump (kg / m3)

γ： Gravity of liquid delivered by pump γ=ρ g (N/ m3)

g: Gravitational acceleration (M / s)

Mass flow QM= ρ Q T / h or kg / S