什么是水泵的功率?

　　功率：在單位時(shí)間內(nèi)，機(jī)器所做功的大小叫做功率。通常用符號(hào)N來表示。常用的單位有：公斤·米/秒、千瓦、馬力。通常電動(dòng)機(jī)的功率單位用千瓦表示;柴油機(jī)或汽油機(jī)的功率單位用馬力表示。動(dòng)力機(jī)傳給水泵軸的功率，即原動(dòng)機(jī)傳支泵軸上的功率，稱為軸功率，用P表示，可以理解為水泵的輸入功率，通常講水泵功率就是指軸功率。

　　水泵銘牌上功率中：P1是電機(jī)輸入功率，P2是電機(jī)輸出功率，也就是軸功率！

　　泵的有效功率又稱輸出功率，用Pe表示。它是單位時(shí)間內(nèi)從泵中輸送出去的液體在泵中獲得的有效能量。

　　因?yàn)閾P(yáng)程是指泵輸出的單位重液體從泵中所獲得的有效能量，所以，揚(yáng)程和質(zhì)量流量及重力加速度的乘積，就是單位時(shí)間內(nèi)從泵中輸出的液體所獲得的有效能量——即泵的有效功率：

　　方程式為Pe=ρgQH(W)=γQH(W)

　　式中ρ——泵輸送液體的密度(kg/m3);

　　γ——泵輸送液體的重度(N/m3);

　　Q——泵的流量(m3/s);

　　H——泵的揚(yáng)程(m);

　　g——重力加速度(m/s2)。

　　軸功率P和有效功率Pe之差為泵內(nèi)的損失功率，其大小用泵的效率來計(jì)量。泵的效率為有效功率和軸功率之比，用η表示。

　　送出去的水多，作功當(dāng)然多，送出去少，作的功也少，電流也應(yīng)少了。水泵的功率(KW)=揚(yáng)程(m)×流量(m3/s)×流體的重度(水取1000kg/m3)÷102(功率轉(zhuǎn)換系數(shù))÷泵的效率(約70%左右)，而電機(jī)功率P=I×U去表示，功率大電流也就大了。

　　由于軸承和填料的摩擦阻力;葉輪旋轉(zhuǎn)時(shí)與水的摩擦;泵內(nèi)水流的漩渦、間隙回流、進(jìn)出、口沖擊等原因。必然消耗了一部分功率，所以水泵不可能將動(dòng)力機(jī)輸入的功率完全變?yōu)橛行Чβ?，其中定有功率損失，也就是說，水泵的有效功率與泵內(nèi)損失功率之和為水泵的軸功率?！?/p>

水泵功率計(jì)算公式?

　　1、離心泵功率計(jì)算公式

　　流量×揚(yáng)程×9.81×介質(zhì)比重÷3600÷泵效率

　　流量單位：立方/小時(shí)， 揚(yáng)程單位：米

　　P=2.73HQ/η,

　　其中H為揚(yáng)程,單位m,Q為流量,單位為m3/h,η為泵的效率.P為軸功率,單位KW. 也就是泵的軸功率P=ρgQH/1000η(kw),其中的ρ=1000Kg/m3,g=9.8

　　比重的單位為Kg/m3,流量的單位為m3/h,揚(yáng)程的單位為m,1Kg=9.8牛頓

　　則P=比重*流量*揚(yáng)程*9.8牛頓/Kg

　　=Kg/m3*m3/h*m*9.8牛頓/Kg

　　=9.8牛頓*m/3600秒

　　=牛頓*m/367秒

　　=瓦/367

　　上面推導(dǎo)是單位的由來,上式是水功率的計(jì)算,軸功率再除以效率就得到了.設(shè)軸功率為Ne，電機(jī)功率為P，K為系數(shù)(效率倒數(shù))

　　電機(jī)功率P=Ne*K (K在Ne不同時(shí)有不同取值，見下)

　　Ne≤22 K=1.25 22 55

　　2、渣漿泵軸功率計(jì)算公式

　　流量Q M3/H 揚(yáng)程H 米H2O 效率n % 渣漿密度A KG/M3 軸功率N KW

　　N=H*Q*A*g/(n*3600)

　　電機(jī)功率還要考慮傳動(dòng)效率和安全系數(shù)。一般直聯(lián)取1，皮帶取0.96，安全系數(shù)1.2

　　3、離心泵軸功率和電機(jī)功率的計(jì)算

　　工程設(shè)計(jì)人員，在確定離心泵流量揚(yáng)程之后，需要確定水泵的另外一個(gè)重要參數(shù)：水泵電機(jī)功率。很多時(shí)候只要按照樣本，根據(jù)流量，揚(yáng)程參數(shù)就可以確定水泵的電機(jī)型號(hào)及電機(jī)功率。

　　我們可以根據(jù)能量守恒原理，推導(dǎo)出水泵電機(jī)的技術(shù)公式。

　　水泵做的有效功W=Mgh(把一定重量的介質(zhì)送到一定的高度h，h即為揚(yáng)程)

　　——M為水的質(zhì)量m=ρV(ρ是介質(zhì)的密度，V介質(zhì)的體積)

　　V=Qt(Q表示水泵的流量，t表示水泵工作時(shí)間)

　　所以水泵做的有效功W=ρQtgH

　　水泵的有效功率P=W/t=ρQgH

　　水泵的軸功率(實(shí)際輸出功率)為P1=ρQgH/η

　　——η表示水泵的效率

　　實(shí)際電機(jī)功率P2=γP1

　　——γ表示電機(jī)的安全余量(γ的取值范圍1.1—1.3，一般選1.2)

　　如果我們打的介質(zhì)就是水，那么電機(jī)功率計(jì)算公式為P2=(1.2QgH)/(3600*η)

　　其中流量Q的單位是：m3/h

　　揚(yáng)程H的單位是：m

　　需要注意的是：根據(jù)公式計(jì)算出來的P2，不一定正好是電機(jī)功率，如33.56kw，那我們選電機(jī)就選37kw，如果是30.56kw，那我們就選30kw的電機(jī)。

　　* 通過以上我們公式推導(dǎo)我們可以知道以下幾個(gè)情況

　　1、不論什么廠家，在流量，揚(yáng)程確定的情況下，實(shí)際有效功都是固定的

　　2、水泵耗電多少不看水泵電機(jī)功率，要看水泵的軸功率。同樣是配30kw的電機(jī)，一家的軸功率是20.56kw，一家是25.18kw，明顯是20.56kw要節(jié)能。而軸功率的大小關(guān)鍵是水泵的效率！

      以上關(guān)于【工業(yè)常用水泵功率計(jì)算公式】由水泵廠家上海瑞柘環(huán)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