Pumps and pumping system bureau of energy efficiency 118 figure 6. A typical composite curve includes the pump performance curves, horsepower curves and npsh required. Fundamentals of fluid mechanics chapter 12 pumps and. A centrifugal pump s complete characteristics chart fourquadrant characteristic curves selection chart is primarily established on the basis of experiments and depends on the pump type. Pump performance curves generally show performance for various impeller diameters or trims. Research article a onedimensional flow analysis for the. Pdf laboratory report centrifugal pump anh phuong le. The pump performance curve describes the relation between the flowrate and the head for the actual pump.
On monitoring of systems or pump characteristic, in principle it has to be decided, which effort for it is adequate altogether. Reading centrifugal pump curves national environmental. Pump characteristic an overview sciencedirect topics. The performance of two centrifugal slurry pumps has been reported for thr er solid materials having different particle size distribution psd in terms of head, capacity, and power characteristics. Typically, the efficiency of the pump at converting the power supplied to the pump into kinetic energy of the fluid is also plotted on the pump performance chart. Centrifugal pump performance characteristics for domestic application article pdf available in matec web of conferences 225. Pump headflow curves are typically given for clear water.
Figure 6 shows an example of a doublesuction centrifugal pump with ns 35 rpm according to stepanoff. But in addition variation of efficiency, power, npsh required etc, as the flow is changed, can also be represented on the pump performance curves by the manufacturer. Centrifugal pumps are one of the worlds most widely used type of pump, having an extensive. To change the operating point either the system curve or the pump curve must be changed. The performance of a pump is dependent on the impeller and casing geometry, the size of the pump, the rotational speed and the properties of the flowing fluid. Centrifugal pump performance curves and technical information 0 20 40 60 80 100 120 140 0 10 20 30 40 50 60 70 80 0 100 110 capacity ead ft nps in feet 10 20 30 40 50 10,000 20,000 30,000 40,000 50,000 60,000 70,000 80,000 160 npsh req u i r e d 2 5 0 m i mp e l r dia t r 9 16 45 h e a d c a p a c i t y 0 5 10 15 20 25 30 35 40 gpm lbs. The paper specifies the model of oil pipeline centrifugal pump, made on the basis of electrohydrodynamic analogy method and designed to calculate performance characteristics of the hydraulic machine according to its catalogue data depending on the. Analytical calculations of pump characteristics depend on geometrical dimensions of pump and losses models in di erent parts of pump. Performance characteristics of centrifugal pump conveying soft slurry. Characteristics of irrigation pump performance in major. Performance characteristics of centrifugal pump conveying soft.
As can be seen, the performance charts use a discharge q usually in m 3 h and pump head h usually in m as basic performance variables. Effect of impeller trimming on pump performance 49 figure 18. Multiplespeed pump performance curves 45 figure 16. Each of the characteristics is explained in the next.
A centrifugal pumps complete characteristics chart fourquadrant characteristic curves selection chart is primarily established on the basis of experiments and depends on the pump type. This paper presents some of the results of a study of grand coulee pumpingplant characteristics. Identification, qualification, and quantification methods for estimating potential cost savings. Effects of reducing speed on a pump s operating characteristics 52. The performance characteristics of the centrifugal pump was tested under varying proportions of suction and delivery lifts for a wide range of total lifts. Generalized performance characteristics of refrigeration. A series of formulae for calculating losses exist, but they lack accuracy when applied to. The magnitude of this change depends upon the dimensions and shape of the waterways and on the operating speed of the impeller. In addition the pump performance is predicted by general.
Theory one way of illustrating pump characteristics is to construct contour lines of. How to read a pump curve 101 taco comfort solutions. The characteristics of a modern, highhead, highefficiency pump are analyzed and presented in the manner proposed. Centrifugalpump performance as a ffected by d esign features by r. All types of pumps will be described in this chapter. Centrifugal pump exercise b objective to create head, power and efficiency characteristic curves for a centrifugal pump. Shut off head is the head developed by the pump at zero flow. Performance characteristics of centrifugal pump conveying. Pump characteristicssuch as flow, pressure, efficiency and brake horsepowerare shown graphically on a pump curve. Suitable for application pump speeds up toapi674 1995andhydraulicinstitutespeedlimitations. Pdf a study on performance characteristics of a centrifugal pump was carried out in the hydraulic laboratory. Azouz 2, 1 department mechanical engineering, faculty of engineering, lebanese international university, beirut, lebanon. Curves relating total head, efficiency, power, and net positive suction head required npshr to discharge or pump capacity q are utilized to describe the operating properties characteristics of a pump. Centrifugal pump performance curves and technical information.
Pdf laboratory report centrifugal pump anh phuong le vu. Pump curves are a diagnostic tool, for establishing pump performance in an operating system. Performance characteristics of centrifugal pumps springerlink. That is, analyze the system to determine the pump head required as a function of flow rate through the pump this will form the system line. If the pump characteristic can be assumed linear, the transfer matrix between both ends of the pump can be written as follows 74. Centrifugal pump performance test inspection for industry. Burt2 luis perez urrestarazu3 abstract well pump tests 12,876 in three central california groundwater basins were characterized and described according to their spatial distribution. This is the primary information reported in the pump performance curves and very important information regarding most of the pump calculations related to differential pressure across the pump. For a pump user shut off pressure of the centrifugal pump is an important tool to identify the priming losscavitation of the pump.
For a given pump geometry and operating speed, the velocities of the liquid vary with the flow rate. Typically a pump performance curve will carry information about the following points. Performance characteristics of centrifugal slurry pumps. Each of the characteristics is explained in the next sections for propeller pumps. Analyzing the pump by itself gives an indication of its capabilities and performance based on the speed of rotation, internal geometry, cost factors, etc. The three most commonly used graphical representations of pump performance are. To do that, an engineer would refer to a pumps composite curve. Other important information for a proper pump selection is also included like efficiency curves, npsh r curve, pump curves for several impeller diameters and different speeds, and power consumption. The size of the pump, 2x38 is shown in the upper section of the graph. Pdf experimental study on performance characteristics of a small.
Reading centrifugal pump curves the environmental finance. Understanding centrifugal pump curves when selecting a centrifugal pump, one should match the performance of the pump to that needed by the system. Typical performance characteristics for a centrifugal pump of a given size operating at a constant impeller speed. Cem sorusbay engine performance parameters engine performance parameters are power, torque and specific fuel consumption. It is good practice to select a pump with an impeller. The performance of centrifugal pumps is only partially determined by analysis testing is usually required. Pdf experimental study on performance characteristics of. Centrifugal pump characteristic curve components of.
In industry, characteristics of all pumps are usually read from its qh curve or performance curve flow rate height. Consequently, centrifugal pumps develop different heads at. Pdf water pressure problems at home can be quite frustrating in daily life which is comes in different ways of complication. Generalized performance characteristics of refrigeration and. Mckee, gareth forbes, ilyas mazhar, rodney entwistle and ian howard curtin university, western australia summary.
Generalized performance characteristics of refrigeration and heat pump systems article pdf available in physics research international 20109 november 2010 with 2,051 reads how we measure. As not to damage the internal parts of the pump open the discharge valve slightly till the flow rate reaches the first value indicated in pump performance curve provided by pump supplier. The performance characteristics of slurry pumps are poor as compared to the conventional pump, because slurry pump efficiency has influence on various factors. Dimensionless characteristics of centrifugal pump p. Characteristics of irrigation pump performance in major irrigated areas of california.
This set of four curves is known as the pump characteristic curves or pump performance curves. Pump performance characteristics and their relationship to overall systems operation. Pressure is the driving force responsible for the movement of the fluid. Centrifugal pump characteristics 21 of 34 duration. The energy transfer in a centrifugal pump is accomplished by changing the state of motion of the liquid. Hydraulic systems behavior and its effect on energy, reliability, and controllability. Rapid or highcapacity vacuum pumping to 103 torr of contaminating gases and vapors is generally most economically performed by steamjet vacuum pumps. Heterogeneous ejector ejector pump \ supersonic ejector thrust augmenter nk 20. Foams and bubbles generate noise and causes cavitation overheating of oil poor lubricant and increases the internal leakage, reducing pump capacity wrong selection of oil. Whether permanent, or with a mobile measuring system only from time to time, whether measuring is cyclically or daily or one carried out only weekly is sufficient. Change in total head produced by the pump, h t power input to the pump, p m pump efficiency, e. Brake torque is normally measured with a dynamometer engine is mounted on a test bed and the shaft is connected to the dynamometer rotor. The operating point of a centrifugal pump, also called its duty point, is given by the intersection of the pump characteristic curve with the system curve.
Experimental results are presented for pump performance head, overall efficiency and electrical power input as a function of the flow rate. For the considered refrigerationheat pump systems, we observe four special operation points as pointed out in figure 1. Given the significant amount of electricity attributed to pumping systems, even small. If required, the measurement of the bearing temperature will be performed for a specified operating time.
A pump performance curve indicates how a pump will perform in regards to pressure head and flow. Pump performance characteristics are first analyzed independently of the rest of hydraulic system and then as a part of the system. Pdf centrifugal pump performance characteristics for. A curve is defined for a specific operating speed rpm and. The operating characteristics of a centrifugal pump may be described or illustrated by using graphs of pump performance. Pdf centrifugal pump performance characteristics for domestic. Effects of reducing speed on a pumps operating characteristics 52. The choice of pump for a given application depends largely on how the pump headflow characteristics match the requirement of the system downstream of the pump.
Pump characteristic curves also offer the opportunity to establish the optimum solution to operate the pumppumps at or closest to the bep as well as ascertain the implication of operating away from the bep. The present experimental study deals with the effect of varying different soft slurry concentrations ranging from 0 to 18 % by weight on the performance characteristic of a centrifugal pump. Power that is not converted into kinetic energy is lost as heat. The pump system assessment professional should have a thorough understanding of.
Manufacturers will put several different trim curves on a pump performance curve to make pump specification easier, although this sometimes makes the pump performance curve more difficult to read. Pump efficiencies typically range from about 50% to 80%. Characteristics of irrigation pump performance in major irrigated areas of california sierra a. The measurement is taken on the bearing bracket on the outside at the level and position of the pump side or motor side bearing in horizontal direction. Other factors affecting pump performance presence of foreign particles cause damage to the internal surfaces of a pump. Lesson 28 characteristic curves of centrifugal pumps. On xy plot, head is plotted in y axis while flow is plotted in x axis.
A centrifugal pump converts driver energy to kinetic energy in a liquid by accelerating the fluid to the outer rim of an impeller. Start the centrifugal pump take the reading of the discharge pressure, flow rate, suction pressure and pump ampere. Figure 3c typical deep well residential submersible pump. Positive displacement pumps have a constant torque characteristic, whereas centrifugal pumps demonstrate variable torque characteristics. A comparative study on centrifugal pump designs and two.
This paper describes the technique of determining the complete operating characteristics of a hydraulic machine such as a centrifugal pump or a turbine, together with a. The centrifugal pumps for building services applications should be in accordance to hydraulic institute standards and all hydronic piping is in accordance with asme b 31. Pressure, friction and flow are three important characteristics of a pump system. Pump performance curves are primarily used to predict the variation of the differential head across the pump, as the flow is changed. The flow rate q and the developed head h are both determined by the intersection.