什么是水泵的功率?

　　功率：在单位时间内，机器所做功的大小叫做功率。通常用符号N来表示。常用的单位有：公斤·米/秒、千瓦、马力。通常电动机的功率单位用千瓦表示;柴油机或汽油机的功率单位用马力表示。动力机传给水泵轴的功率，即原动机传支泵轴上的功率，称为轴功率，用P表示，可以理解为水泵的输入功率，通常讲水泵功率就是指轴功率。

　　水泵铭牌上功率中：P1是电机输入功率，P2是电机输出功率，也就是轴功率！

　　泵的有效功率又称输出功率，用Pe表示。它是单位时间内从泵中输送出去的液体在泵中获得的有效能量。

　　因为扬程是指泵输出的单位重液体从泵中所获得的有效能量，所以，扬程和质量流量及重力加速度的乘积，就是单位时间内从泵中输出的液体所获得的有效能量——即泵的有效功率：

　　方程式为Pe=ρgQH(W)=γQH(W)

　　式中ρ——泵输送液体的密度(kg/m3);

　　γ——泵输送液体的重度(N/m3);

　　Q——泵的流量(m3/s);

　　H——泵的扬程(m);

　　g——重力加速度(m/s2)。

　　轴功率P和有效功率Pe之差为泵内的损失功率，其大小用泵的效率来计量。泵的效率为有效功率和轴功率之比，用η表示。

　　送出去的水多，作功当然多，送出去少，作的功也少，电流也应少了。水泵的功率(KW)=扬程(m)×流量(m3/s)×流体的重度(水取1000kg/m3)÷102(功率转换系数)÷泵的效率(约70%左右)，而电机功率P=I×U去表示，功率大电流也就大了。

　　由于轴承和填料的摩擦阻力;叶轮旋转时与水的摩擦;泵内水流的漩涡、间隙回流、进出、口冲击等原因。必然消耗了一部分功率，所以水泵不可能将动力机输入的功率完全变为有效功率，其中定有功率损失，也就是说，水泵的有效功率与泵内损失功率之和为水泵的轴功率。　

水泵功率计算公式?

　　1、离心泵功率计算公式

　　流量×扬程×9.81×介质比重÷3600÷泵效率

　　流量单位：立方/小时， 扬程单位：米

　　P=2.73HQ/η,

　　其中H为扬程,单位m,Q为流量,单位为m3/h,η为泵的效率.P为轴功率,单位KW. 也就是泵的轴功率P=ρgQH/1000η(kw),其中的ρ=1000Kg/m3,g=9.8

　　比重的单位为Kg/m3,流量的单位为m3/h,扬程的单位为m,1Kg=9.8牛顿

　　则P=比重*流量*扬程*9.8牛顿/Kg

　　=Kg/m3*m3/h*m*9.8牛顿/Kg

　　=9.8牛顿*m/3600秒

　　=牛顿*m/367秒

　　=瓦/367

　　上面推导是单位的由来,上式是水功率的计算,轴功率再除以效率就得到了.设轴功率为Ne，电机功率为P，K为系数(效率倒数)

　　电机功率P=Ne*K (K在Ne不同时有不同取值，见下)

　　Ne≤22 K=1.25 22 55

　　2、渣浆泵轴功率计算公式

　　流量Q M3/H 扬程H 米H2O 效率n % 渣浆密度A KG/M3 轴功率N KW

　　N=H*Q*A*g/(n*3600)

　　电机功率还要考虑传动效率和安全系数。一般直联取1，皮带取0.96，安全系数1.2

　　3、离心泵轴功率和电机功率的计算

　　工程设计人员，在确定离心泵流量扬程之后，需要确定水泵的另外一个重要参数：水泵电机功率。很多时候只要按照样本，根据流量，扬程参数就可以确定水泵的电机型号及电机功率。

　　我们可以根据能量守恒原理，推导出水泵电机的技术公式。

　　水泵做的有效功W=Mgh(把一定重量的介质送到一定的高度h，h即为扬程)

　　——M为水的质量m=ρV(ρ是介质的密度，V介质的体积)

　　V=Qt(Q表示水泵的流量，t表示水泵工作时间)

　　所以水泵做的有效功W=ρQtgH

　　水泵的有效功率P=W/t=ρQgH

　　水泵的轴功率(实际输出功率)为P1=ρQgH/η

　　——η表示水泵的效率

　　实际电机功率P2=γP1

　　——γ表示电机的安全余量(γ的取值范围1.1—1.3，一般选1.2)

　　如果我们打的介质就是水，那么电机功率计算公式为P2=(1.2QgH)/(3600*η)

　　其中流量Q的单位是：m3/h

　　扬程H的单位是：m

　　需要注意的是：根据公式计算出来的P2，不一定正好是电机功率，如33.56kw，那我们选电机就选37kw，如果是30.56kw，那我们就选30kw的电机。

　　* 通过以上我们公式推导我们可以知道以下几个情况

　　1、不论什么厂家，在流量，扬程确定的情况下，实际有效功都是固定的

　　2、水泵耗电多少不看水泵电机功率，要看水泵的轴功率。同样是配30kw的电机，一家的轴功率是20.56kw，一家是25.18kw，明显是20.56kw要节能。而轴功率的大小关键是水泵的效率！

      以上关于【工业常用水泵功率计算公式】由水泵厂家上海瑞柘环保分享！

　　What is the power of the water pump?

　　Power: in unit time, the amount of work done by the machine is called power. It is usually represented by the symbol n. Commonly used units are: kg · M / s, kW, HP. Usually, the power unit of the motor is expressed in kW; The unit of power of a diesel or gasoline engine is expressed in horsepower. The power transmitted by the power machine to the feed pump shaft, that is, the power on the prime mover transmission pump shaft, is called shaft power, which is represented by P, and can be understood as the input power of the pump. Generally speaking, pump power refers to shaft power.

　　Among the powers on the nameplate of the water pump: P1 is the input power of the motor, P2 is the output power of the motor, that is, the shaft power!

　　The effective power of the pump is also called output power, which is expressed by PE. It is the effective energy obtained by the liquid delivered from the pump in unit time.

　　one thousand six hundred and thirty-five trillion and three hundred and three billion nine hundred and eighty-four million three hundred and eighty-six thousand three hundred and fourteen jpg

　　Because head refers to the effective energy obtained from the pump by the unit weight liquid output by the pump, the product of head, mass flow and gravitational acceleration is the effective energy obtained by the liquid output from the pump in unit time - that is, the effective power of the pump:

　　The equation is PE= ρ gQH(W)= γ QH(W)

　　Where ρ—— Density of liquid delivered by the pump (kg/m3);

　　γ—— The gravity of the liquid delivered by the pump (n/m3);

　　Q - pump flow (m3/s);

　　H - pump lift (m);

　　G -- gravitational acceleration (m/s2).

　　The difference between the shaft power P and the effective power PE is the power loss in the pump, which is measured by the efficiency of the pump. The efficiency of the pump is the ratio of effective power to shaft power, using η express.

　　If more water is sent out, of course, more work is done. If less water is sent out, less work is done, and the current should also be less. Power of water pump (kw) = head (m) × Flow (m3/s) × The gravity of the fluid (water is 1000kg/m3) ÷ 102 (power conversion coefficient) ÷ the efficiency of the pump (about 70%), and the motor power p=i × U goes to indicate that high power and current will increase.

　　Due to the friction resistance between bearing and packing; Friction with water when the impeller rotates; The vortex of water flow in the pump, gap reflux, inlet and outlet impact and other reasons. Some power must be consumed, so the pump cannot completely change the power input by the power machine into effective power, in which there must be power loss, that is, the sum of the effective power of the pump and the power lost in the pump is the shaft power of the pump.

　　Pump power calculation formula?

　　1. Power calculation formula of centrifugal pump

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

　　Flow unit: cubic meter / hour, lift unit: meter

　　P=2.73HQ/ η,

　　Where h is the lift, unit m, q is the flow, unit m3/h, η Is the efficiency of the pump P is shaft power, in kw That is, the shaft power P of the pump= ρ gQH/1000 η (kw), of which 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 Newton *m/3600 seconds

　　=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 Set the shaft power as ne, the motor power as P, and K as the coefficient (reciprocal of efficiency)

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

　　Ne≤22 K=1.25 22 55

　　2. Calculation formula of shaft power of slurry pump

　　Flow Q m3/h head 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 should 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. Calculation of shaft power and motor power of centrifugal pump

　　After determining the flow head of centrifugal pump, engineers need to determine another important parameter of pump: pump motor power. In many cases, the motor model and power of the water pump can be determined according to the sample, flow and lift parameters.

　　We can deduce the technical formula of pump motor according to the principle of energy conservation.

　　The effective work done by the water pump w=mgh (send a certain weight of medium to a certain height h, h is the lift)

　　——M is the mass of water M= ρ V( ρ Is the density of the medium, V the volume of the medium)

　　V=qt (Q represents the flow of the water pump, and T represents the working time of the water pump)

　　So the effective work done by the water pump w= ρ QtgH

　　Effective power of water pump p=w/t= ρ QgH

　　The shaft power (actual output power) of the water pump is P1= ρ QgH/ η

　　—— η Indicates the efficiency of the water pump

　　Actual motor power P2= γ P1

　　—— γ Indicates the safety margin of the motor( γ Value range of 1.1-1.3, generally 1.2)

　　If the medium we hit is water, the motor power calculation formula is p2= (1.2qgh) / (3600* η)

　　The unit of flow Q is m3/h

　　The unit of lift h is: M

　　It should be noted that P2 calculated according to the formula is not necessarily the motor power. For example, if it is 33.56kw, we choose 37KW as the motor. If it is 30.56kw, we choose 30kW as the motor.

　　*Through the above formula derivation, we can know the following situations

　　1. No matter what manufacturer, the actual effective work is fixed when the flow and head are determined

　　2. The power consumption of the water pump does not depend on the motor power of the water pump, but on the shaft power of the water pump. It is also equipped with 30kW motors. The shaft power of one is 20.56kw and that of the other is 25.18kw. Obviously, 20.56kw should be energy-saving. The key to the shaft power is the efficiency of the water pump