1.0 水泵基础-ITT 水泵培训资料

1、PUMPSTheory and application水泵基础将液体提升到一定高度的机械(将电能转化成机械能)水泵培训资料(一.1）WHAT IS A PUMP? 水泵是甚麼?Defined as:.a machine to transfer a fluid運送流體的機器按用途分:空调泵.消防泵,给水泵.潜水泵.排污泵等按结构分:管道泵 一般为立式单级泵,进出口处于水平面且相等端吸泵,侧进上出双吸泵(中开泵),侧进侧出直联泵 泵头与电机使用同一根轴承长联轴器泵潜水泵水泵分类1水泵分类2按介质分:清水泵 介质清水且无温度要求热水泵 介质清水温度要求90C污水泵 介质污水油泵 介质为油 油温100

2、C为热油泵油分轻油和重油我们的泵基本只能输送轻油化工泵 介质为酸碱等化工液体按材质分:铸铁泵.不锈钢泵.青铜泵.塑料泵等按级数分:单级泵.多级泵一. 泵体,又称为泵头包括: 泵壳,叶轮,机械密封，轴承 密封: 材质为石墨/陶瓷/碳化钨(硅)部分用途依然应该使用填料密封(如消防)二. 电机,又称为马达三. 其它部分如卧式长联轴器泵包括联轴器,底板等水泵组成Centrifugal Impeller Types離心泵葉輪種類参数(1)流量(Q) 单位时间内的出水量单位:吨/小时=T/h 升/秒=L/s 1T/h=3.6L/s(2)扬程(H) 将液体提升的高度或出口的压力单位:米=M 压力习惯用公斤表

3、示 1KG=1BAR=10M(3)液体介质分清水.热水.污水.油.其它化工液体,水泵只是一种习惯说法,不一定只输送水,尤其化工泵须知道液体PH值,浓度,比重,粘度等.(4)介质温度(5)承压(指水泵正常运行所能承受的最大压力)选型基本要素 - 1转速(R) 单位:RPM=转/分钟 电机每分钟转得速度2900转电机习惯称为2级电机,1450转 电机习惯称为4级电机空调泵多为噪音比较低的1450RPM,供水泵多为2900RPM电压(T)通常分三相380伏 3X380V 单相220伏 1X220V通常只有小型水泵才有220V.水泵形式:立式或卧式材质要求:铸铁,不锈钢,青铜等是否具有自吸功能其它重要

4、参数功率(N) 单位:KW 通常指电机输出功率P2赫兹:国内为50HZ 国外多为60HZ防护级:IP44/54/55/68密封级:B/B3/F*气蚀余量其他要素-1PUMPING SYSTEMS “CAPACITY ”水泵系統 “流量”The amount of liquid flowing through a pumping system is known as the capacity or flow rate流量是液體流過水泵系統的量Typical units used 使用單位:m3/h or m3/s l/s or l/ming.p.m.us g.p.m.PUMPING SYSTEM

5、S “CAPACITY ”水泵系統 “流量”PUMPING SYSTEMS“ STATIC HEAD ”靜揚程The components of Static head are the elevation between :- the surface of the liquid at the point of suction and at the point of discharge靜揚程是液體於進水點及出水點之距离Static head also accounts for the pressure differential between the point of suction and t

6、he point of discharge靜揚程亦說明進水點與出水點之壓差Static head does not vary with capacity靜揚程不會隨著流量而改變ITT FluidPUMPTo Loading RackDN 80 (3”) Pipe6 m6 m4.5 m6 m0.6 mIn this example the static head (Hs) is equal to 靜揚程等於:4.5 + 0.6 - 3 = 2.1 mHsExample 2 例子 2PUMPING SYSTEMS “ STATIC HEAD ”靜揚程PUMPING SYSTEMS “ DYNAMI

7、C HEAD ” 動揚程A pump must overcome the resistance of a pumping system in order to cause the liquid to flow completely through the system水泵需克服水泵系的阻力使液體流動Resistance to liquid flow is known as a pumping systems Dynamic Head系統的動揚程就是對於液體流動的阻力Pump水泵Resistance阻力Head 揚程ITT GroupDynamic head losses are those l

8、osses that are realised once fluid begins to flow through the pumping system動揚程是當液體開始流動時系統的實際壓損Dynamic head losses are a function of capacity 動揚程會隨著不同流量而變化3.5 bar (50 psi)2.1 bar (30psi)PUMPING SYSTEMS “ DYNAMIC HEAD ” 動揚程A typical friction loss table for piping illustrates friction losses as a func

9、tion of capacity, pipe diameter, pipe length and viscosity 磨損表顯示出磨損跟流量, 管道直徑, 管長及黏度的關係speedWater (viscosity = 1 cSt)speedLubricating oil SAE40 (viscosity = 150 cSt)PUMPING SYSTEMS “ FRICTION HEAD LOSSES ”磨損ITT FluidPUMPING SYSTEMS “ FRICTION HEAD LOSSES ”压損PUMPTo Loading RackDN 80 (3”) Pipe6 m6 m4.5

10、 m6 m0.6 m6 mHsExample 2In this example the friction losses (Dp) is equal to磨損等於:Flow 流量= 800 l/minTwo elbows 90 (equivalent length)2個相同長度90彎頭= 2 x1.5 = 3.0 mPipe losses 管道損失= (6+6+4.5+6)+3.0)x(10/100) = 2.55 mLoading rack losses負載損失= 2.8 m Total friction losses 總磨損= 2.55+2.8 = 5.35 m PUMPING SYSTEM

11、S “TOTAL DYNAMIC HEAD”總揚程Dynamic head represents the resistance of a pumping system while the pumped fluid is in motion動揚程是液體流動之後系統的阻力Static head is the resistance of a pumping system before the liquid is set into motion 靜揚程是液體流動之前系統的阻力Now what we have to do ?The systems total dynamic head is simply

12、 簡單地說:Static Head 靜揚程+ Dynamic Head 動揚程 = Total Dynamic Head 總揚程PUMPING SYSTEMS “TOTAL DYNAMIC HEAD”總揚程PUMPTo Loading RackDN 80 (3”) Pipe6 m6 m4.5 m6 m0.6 m6 mIn this example the total dynamic head (TDH) is equal to 總揚程:Static head 靜揚程= 2.1 m Dynamic head 動揚程= 5.35 m Total dynamic head 總揚程= 2.1+5.35

13、 = 7.45 mExample 2PUMPING SYSTEMS “TOTAL DYNAMIC HEAD”總揚程ITT Fluid Technology - Commercial Products GroupPUMPING SYSTEMS 水泵系統 其他System LayoutBlueprintsIt is a good system design to include suction and discharge valves in the system. 良好的系統應有進口及出口閘閥Isolating the pump for maintenance considerations以便維修

14、A discharge check valve may also be required in high discharge head applications (to prevent water hammer) 安裝止回閥以防水鎚現象Using the discharge valve as a throttling valve to control the pump 使用出口閘閥控制水泵ITT Fluid Technology - Commercial Products GroupPUMPING SYSTEMS “ SYSTEM CURVE ”系統曲線A System Curve is a

15、graphical representation of the resistance behaviour (TDH) of a pumping system over its entire capacity range系統曲線是用來表示系統的總揚程跟流量的關係A system curve shows系統曲線顯示出:-the static head component 靜揚程( this is constant over the entire capacity range這是一個不變值)the dynamic head component 動揚程( which increases with ca

16、pacity流量增加, 動揚程增加)HeadCapacityStatic headDynamic head流量揚程畫上曲線流量揚程不同葉輪直徑的性能曲線流量揚程效率曲線The best efficiency point (BEP) is the highest efficiency point on the curve 最佳效率點是曲線圖上最高效率的工作點Head CapacityF 200 (8”)F 150 (6”)52%62%56%65%Centrifugal pump curves typically show hydraulic efficiency points離心泵性能曲線圖通常

17、顯示出水力效率PUMP HYDRAULICS ”CENTRIFUGAL PUMP CURVE”水泵水力學 “離心泵性能曲線”Typical Performance Curve水泵性能曲線圖Best Efficiency Point最佳效率點P3P2P1Power Requirements 功率要求ITTPUMP HYDRAULICS“ CENTRIFUGAL PUMP CURVE ”性能曲線圖Head揚程 Capacity 流量Pump curves typically show the “absorbed power”(brake horsepower) required to operat

18、e the pump at various points along its Head-Capacity curve水泵性能曲線顯示出在不同工作點上需要操作水泵的軸功率The absorbed power shown on the curve is based on pumping water (specific gravity = 1.0) 曲線圖上的軸功率是基於水來計算的Q - HF 200 (8”)F 150 (6”)Q - PPower in Kw(bhp軸功率)Power Absorbed Curves軸功率曲線Typical Performance Curve 水泵性能曲線圖电动机功率的决定全曲线不过载工作点轴功率x 1.15首先要知道工作点的轴功率测试估算(流量(T/h) x 扬程(m) / 效率/367 = 轴功率(kw)NPSH氣蝕餘量Head CapacityQ - HQ - NPSHrNPSHr in metres (feet)Pump curves typically show the Net Positive Suction Head Required to op