Multi Pump 2

ABSTRACT This experiment report discusses about the several types of pumps that can be found in industry with different characteristics, performance and also application. The concepts of energy conversion was used to compare the performance curves of different pumps.The relationship between pressure head, flow rate pressure head, flow rate, power consumed and efficiency for a pump is investigated. For this experiment, we have tested only on Centrifugal Pump, Axial to investigate their characteristics when different flow rates are applied. The centrifugal pump is the type most widely used in the chemical industry for transporting liquids of all types. The size and types best suited for a particular operation can be determined by engineering of the problem. The capacity of the pump is defined as the volume of the fluid handled per unit time. The performance of a centrifugal pump for a particular rotational speed of the impeller and liquid viscosity is represented by plots of total head against capacity and power against capacity.This report consist of the objectives of the experiment, a brief introduction,working theory of multi pump test rig, the apparatus used to conduct this experiment and the procedures of carrying out the experiment. The data collected are then analyze and discussed. At the end of the report, discussion, errors, and modifications about the experiment are explain. Finally, the conclusion of the experiment is made. OBJECTIVES To investigate the relationship between pressure head, flow rate, power consumed and efficiency for a pump and to compare the performance curves of different pumps. THEORY The pump is a delivery system. It rises up the head of fluid by energy conversion. The input power usually is electrical power (Pin). The output power is (Po) and is dependent on the pump efficiency ( )



Po Pin

Po   .g.Q.H

Where,

 is fluid density ( g is gravity (

m ) s2

kg ) m3

m3 ) s H is delivery head

Q is flow rate (

Pin  T 

2N T 60

PROCEDURE 1. 2. 3. 4. 5.

6. 7. 8. 9.

A pump has been selected to be tested The dynamometer motor torque ensured set to zero correctly The test rig switched on The motor speed raised to maximum : 1450rev/min Six equi-spaced points has been selected throughout pressure reading range, at which flow reading is taken. Note: the actual pressure head of the pump is the difference between the pressure gauge reading in m.H2O and the vacuum gauge reading in m.H2O, at a particular rate of flow. The control valve is adjusted to the first of the selected pressure gauge readings The rate of flow is measured using the graduated sight glass on the volumetric tank and the stopwatch. The torque reading at each flow rate is recorded Steps 3-8 is repeated for two other motor speeds

DATA COLLECTION 800rpm

Reading 1 2 3 4 5

Pressure (m.H₂O) 1.0 1.0 1.0 1.0 1.0

Vacuum (m.H₂O) 0 0 0 0 0

Pump Head (m.H₂O) 0.0200 0.0240 0.0250 0.0255 0.0255

Volume Time Flow rate Torque (ltr) (s) (mᵌ/s) (N.m) 5 18.2 0.0002747 0.23 5 15.0 0.0003333 0.25 5 13.0 0.0003846 0.25 5 13.0 0.0003846 0.23 5 12.9 0.0003876 0.22

Input Hydraulic Power Power (W) (W) 19.26843 0.05390 20.94395 0.07848 20.94395 0.09433 19.26843 0.09621 18.43068 0.09696

Vacuum (m.H₂O) 0 0 0 0 0

Pump Head (m.H₂O) 0.0280 0.0350 0.0365 0.0370 0.0380

Volume Time (ltr) (s) 5 9.8 5 7.8 5 7.2 5 7.0 5 7.0

Flow rate (mᵌ/s) 0.0005102 0.0006410 0.0006944 0.0007143 0.0007143

Torque (N.m) 0.33 0.36 0.37 0.37 0.37

Input Hydraulic Power Power Efficiency (W) (W) (%) ή 41.46902 0.14014 0.3379 45.23893 0.22010 0.4865 46.49557 0.24866 0.5348 46.49557 0.25926 0.5576 46.49557 0.26627 0.5727

Vacuum (m.H₂O) 0.00 0.00 0.20 0.25 0.25

Pump Head (m.H₂O) 0.0365 0.0415 0.0435 0.0445 0.0450

Volume Time (ltr) (s) 5 7.0 5 6.6 5 5.2 5 5.4 5 5.4

Flow rate (mᵌ/s) 0.0007143 0.0007576 0.0009615 0.0009259 0.0009259

Torque (N.m) 0.47 0.51 0.50 0.51 0.53

Input Hydraulic Power Power Efficiency (W) (W) (%) ή 73.82743 0.25576 0.3464 80.11061 0.30842 0.3850 78.53982 0.41032 0.5224 80.11061 0.40421 0.5046 83.25221 0.40875 0.4910

Efficiency (%) ή 0.2797 0.3747 0.4504 0.4993 0.5261

1200rpm Pressure Reading (m.H₂O) 1 2.0 2 1.8 3 1.8 4 1.7 5 1.7 1500rpm

Pressure Reading (m.H₂O) 1 3.2 2 2.8 3 2.6 4 2.6 5 2.5

RESULTS

Pump Pressure Head vs Pump Flow Rate 0.0500 0.0450 0.0400 0.0350 800 rpm

Axis Title

0.0300

1200 rpm

0.0250

1500 rpm

0.0200

Linear (800 rpm) Linear (1200 rpm)

0.0150

Linear (1500 rpm)

0.0100 0.0050 0.0000 0.00E+00

2.00E-04

4.00E-04

6.00E-04 Axis Title

8.00E-04

1.00E-03

1.20E-03

Efficiency vs Flow Rate 0.7000

0.6000

Axis Title

0.5000 800 rpm

0.4000

1200 rpm 1500 rpm 0.3000

Linear (800 rpm) Linear (1200 rpm)

0.2000

Linear (1500 rpm)

0.1000

0.0000 0.00E+00

2.00E-04

4.00E-04

6.00E-04 Axis Title

8.00E-04

1.00E-03

1.20E-03

KEVIN NELSON (15118) DISCUSSION The main goal of the experiment is to find the relationship between the pressure head, flow rate, power consumed and efficiency for a pump and to compare the performance curves of different pumps used. According to the theory, the pump is a delivery system which increases the head of the fluid by conversion of energy. The input of the delivery system is electrical power (P in) while the output of the system is (Po) which is dependent of the pump efficiency (η). There are several pumps used in the system which is centrifugal pump, axial flow pump, gear pump and turbine pump.

Where Po=

, Pin =

There are several equations used in this experiment to calculate the head pump. Firstly is the Bernoulli’s equation. There were some assumptions made so that the equation is valid. The flow is assumed to be steady, inviscid, and incompressible. Besides that,the continuity equation is used. The fluid used is water. The density is constant. The area of pipes is same at the inlet and outlet. Therefore, we can consider that the velocity at one point is equal to the other point. Bernoulli equation:

+ Continuity equation:

̇ = ̇ From the result, the pump head increases as the pressure decreases while the flow rate increases as the time decreases. The input power seems to be almost constant or very close values after the first reading while the hydraulic power increases as the experiment continues. After calculating the efficiency from the input power and hydraulic power, the efficiency increases. The torque is almost constant. From the graph, we can see that the pump head is inversely proportional to the flow rate and the efficiency is linearly proportional to the flow rate. By interpreting the graph, the pump head decreases as the flow rate increases, while the efficiency increases as the flow rate increases. In conclusion, the experimental value differ from the theoretical value because by using the equations, other factors such as the surface roughness of the pipe are not considered. The data calculated may differ from the theoretical value maybe due to some errors during the experiment. Firstly is the parallax error. The eyes are not on the right position when taking the reading of the pressure. Besides that, human reactions also may affect the accuracy of the data.This occurs during the reaction time taken when stopping the stop watch after the water fills the tube to a certain level. Instrument error also may occur where the measuring tools were not properly calibrated.

For improvement in the future, digital measurement method should be implemented to assist in collecting data. Weekly maintenance should be done so that there are no components that malfunction in order for the machine to work efficiently. Variable readings should be taken so that the data accuracy of the experiment would increase. CONCLUSION The objective of the experiment is to examine the relationship between the pressure head, flow rate, power consumed and efficiency for a pump and to compare the performance curves of different pumps used as plotted in the graphs. In conclusion, the objective of the experiment has been achieved as the experiment was conducted and analysed. NUR HUWAINA BINTI KHAIRULLAH (13903) DISCUSSION The objective of this experiment is to investigate the relationship between pressure head, flow rate, power consumed and efficiency for a pump. We only used centrifugal pump in this experiment to show the relationships. The pump is used to convert mechanical energy to kinetic energy. The experiment is conducted at three speeds, 800 rpm, 1200 rpm and 1500 rpm and the readings for pressure head, flow rate and power consumed are recorded. We can see from the data recorded that the pump head for all three motor speeds increases. The higher the motor speeds, the higher the pump head. For 800 rpm motor speed, the pump head increases from 0.0200m to 0.0255m. For 1200 rpm, the pump head increases from 0.0280m to 0.0380m and for 1500 rpm, the pump head increases from 0.0365m to 0.0450m.The flow rate in the table is calculated by dividing the volume with the time taken. The flow rate increases as the time taken decreases. For 800 rpm, the flow rate increases from 2.747E-4 mᶟ/s to 3.333E-4 mᶟ/s. For 1200 rpm, the flow rate increases from 5.102E-4 mᶟ/s to 7.143E-4mᶟ/s and for 1500 rpm, the flow rate increases from 7.143E-4 mᶟ/s to 9.259E-4 mᶟ/s. For power consumed by the pump, the power input should increases as the speed increases but in this experiment the readings are not so accurate as there are times where the power input decreases or stay constant as the speed increases due to some errors. We can say that the power input increases as the torque increases. From the table, the efficiency of the pump increases as the hydraulic power increases. The efficiency can be calculated from the ratio of hydraulic power to the input power. For 800 rpm, the efficiency increases from 0.28% to 0.53%. For 1200 rpm, the efficiency increases from 0.34% to 0.57% and for 1500 rpm, the efficiency increases from 0.35% to 0.50% but then drop to 0.49%. From the first graph (Pump Pressure Head vs Pump Flow Rate), the pressure head for all three motor speeds increases as the flow rate increases and from the second graph (Efficiency vs Flow Rate), we can say that for all three motor speeds, the efficiency increases as the flow rate increases.

ERRORS AND MODIFICATIONS The readings recorded throughout this experiment are not so accurate due to some errors. The first one is parallax error. Parallax error occurred when our eye is not parallel to the reading which then will caused inaccurate reading. To overcome this problem, the eyes must be parallel to the scale when taking readings. The second error is human error. This error occurred when taking the time for the water to reach a certain level. A person might not be able to stop the stopwatch at the exact moment the water reach that certain level thus resulting the error. To overcome this, we can take a few readings and after that take the average from all the readings to obtain the accurate readings. CONCLUSION In this experiment, the objective is achieved as we were able to determine the relationship between pressure head, flow rate, power consumed and efficiency for a pump and at the same time we were able to compare the performance curves of different pumps when the graph is plotted. The flow rate increases as the pressure head increases, the power input increases as the torque increases and the efficiency increases as the flow rate increases. FAIQAH BINTI MOHD AZMIR (13795) DISCUSSION Pump is a delivery system. It has been designed to convert mechanical energy into fluid energy. It rises up the head fluid by energy conversion. Head fluid is a specific measurement of water pressure above a geodetic datum. It is usually measured as a water surface elevation, expressed in a unit of meters or feet. Four pump is used in this particular experiment namely centrifugal pump, axial flow pump gear pump and turbine pump. Centrifugal Pump is used to increase the pressure of fluid and make the fluid moves in the pipe. The fluid enters the pump impeller along or near to the rotating axis and is accelerated by the impeller, flowing radially outward into a diffuser or volute chamber (casing), from where it exits into the downstream piping. This pump is used for large discharge through smaller heads. An axial flow pump, or AFP, is a common type of pump that essentially consists of a propeller in a pipe. The propeller can be driven directly by a sealed motor in the pipe or mounted to the pipe from the outside or by a right-angle drive shaft that pierces the pipe. The Axial Flow Pump is used to run at peak efficiency at low flow or high-pressure and high-flow or low pressure. Gear pump uses the meshing of gears to pump fluid by displacement. They are one of the most common types of pumps for hydraulic fluid power applications. Gear Pump varies with speed but remain constant against pressure. Turbine Pump is used to handle the small amount of fluid with high total head.

The pumps used have differences in their characteristics, resulting in the different power input and power output between each pump. Power input and power output can be calculated using the stated equation: Power input, Pin = = Power output, Pₒ = Where, is fluid density g is gravity (=9.81) Q is flow rate H is delivery head Power output is dependent on the efficiency of the pump, therefore the efficiency of the pump is calculated. Pump efficiency, = Another equation that we used to find the value of head pump is Bernoulli’s equation. A few assumptions were made to validify the equation which are the flow is steady, inviscid and incompressible. Bernoulli equation: +

From the result that we obtained after conducting this experiment, we can see that when the motor speed is increased, the pressure and would decrease. When it is operating with different speeds, it gives various values for pressure head, flow rate, and power consumed while we take the reading. Higher flow rate results in slower time. This will allow us to obtain the factors that affect the efficiency of the pumps. We can see clearly from the graph that the efficiency and head pump is directly proportional to the flow rate. This is due to the increasing velocity when the flow rate is faster and the power output is directly proportional to the flow rate. Some of the data that we collected were not accurate. This is because of the errors made throughout the experiment. The first error was parallax error. It was hard to maintain perpendicular vision to the scale because it was positioned at the lower part of the table, resulting in parallax error and inaccurate reading. The second error was categorized as systematic error as it involves the equipments itself. Vibrations that occurred throughout the experiment caused instability in some of the equipment which leads to inaccurate data collection. Modification should be made in the future to make sure that accurate result and data can be obtained. The eye of the observer should be exactly perpendicular to the scale. The instruments should be regularly serviced to reduce unnecessary vibrations.

CONCLUSION The objectives of this experiment were achieved. From the result, we can see clearly the relationship between the flow rates, power consumed, pressure head and efficiency of the pump. In conclusion, the experimental values are differed from the theoretical value because by using the equation, other factors such as the surface roughness of the pipe are not considered including some errors that matter. NURUL NADIA SHUHADA BINTI MAHAMAD SHOBRI (13686) DISCUSSION Interpretation of Data For this experiment, we are going to do Multi-pump Test Rig, an armfield that has been designed to study the operating characteristics of different types of pumps such as a centrifugal pump, an axial flow pump, a gear pump and a turbine pump. These pumps are used to convert mechanical energy into fluid energy and this allows liquids to flow from one place to another. To fully understand the pumps and their characteristics, we have recorded the measurements of head, flow, speed and torque to be determined and compared. We have selected centrifugal pump to be tested with motor speed of 800 rpm. All steps are repeated for other motor speeds of 1200 rpm and 1500 rpm. From the data recorded, we can see that the reading of pump head for all three motor speeds are increasing. For 800 rpm, the head pump readings are increasing from 0.0200 m to 0.0255m and for 1200 rpm, pump head readings show increment from 0.0280 m to 0.0380 m, meanwhile for 1800 rpm, the pump head readings are getting higher from 0.0365 m to 0.0450. These readings are increasing as the equi-spaced points throughout the pressure reading range are increased as well. For the flow rate readings, the volume and time taken readings have been taken from the graduated sight glass on the volumetric tank by using stop watch. The time taken for the liquids to reach 5 liter is showing its decrement for all motor speeds of 800 rpm, 1200 rpm and 1500 rpm. The flow rate readings (in mᶟ/s) decreases from 2.747E-4 to 3.333E-4, 5.102E-4 to 7.143E4 and 7.143E-4 to 9.259E-4 for 800 rpm, 1200 rpm and 1500 rpm respectively. This decrement affects the flow rate of the liquid as the time taken is inversely proportional to the flow rate. So that means, if the time taken for the liquid to reach 5 litre is decreasing, thus the flow rate will be increasing. For the power consumed, the power input readings show that the readings are increasing. However, for 800 rpm, the readings inreases but then decreases. It increases from 19.2 W to 20.9 W but then decreases to 18.4 W. For 1200 rpm, the readings increases from 41.5 W to 46.5 W but remain constant at 46.5 W towards the end. For 1500 rpm, the readings are not stable at the beginning but increases from 78.5 W to 83. 3 W towards the end. Input reading is affected by torque as if the torque increases, the input power will increase as well. In this situation, the

increment of the torque is not steady. So we notice that some errors might occur during the experiment. Efficiency of the pump can be measured from the ratio of hydraulic power to the power input. In this experiment, generally we can conclude that the efficiency of the pump is increasing as the hydraulic power increasing as well. For 800 rpm, it records that the efficiency is increasing from 0.28% to 0.53% and for 1200 rpm, it shows that the efficiency increases from 0.34% to 0.57%, meanwhile for 1500 rpm, the efficiency increases from 0.35% to 0.50% but then drop to 0.49%. From the graph of Pump Pressure Head vs Pump Flow Rate, all results for all three motor speeds have been plotted. The result shows that all three motor speeds are increasing linearly as the pump flow rate increasing. This means that the pump pressure head is directly proportional to pump flow rate. From the second graph of Efficiency vs Flow Rate, all three motor speeds of 800 rpm, 1200 rpm and 1500 rpm show linear increments. This means when the flow rate increases, the efficiency will increase for sure. Thus, efficiency is directly proportional to the flow rate. ERRORS As mentioned earlier, our results for power input readings for all three motor speed are not stable. This could be because of parallax error. There might be an error in reading an torque balance instrument when taking torque reading. The eyes might not be on a line directly perpendicular to the scale. The same error might occurs during taking the reading of time taken for liquid to reach 5 litres. The eyes might not be perpendicular to the scale and the time taken from the stopwatch might not be stopped at the exact moment the liquid reachs a scale of 5 litres. MODIFICATION The only way to overcome parallax error is by taking reading when our eyes are directly perpendicular to the scale. For the time taken is taken at the exact moment the liquid reach volume of 5 litres, it is suggested that the reading for both are taken by the same person. This is because only the person who is taking the reading of the sight gauge and scale knows when is the right moment to stop the stopwatch. CONCLUSION The objectives of this experiment is to study the relationship between pressure head, flow rate, power consumed and efficiency for a pump, and to compare the performance curves of different pumps. For this experiment, we only test centrifugal pump but at three different motor speeds which are 800 rpm, 1200 rpm and 1500 rpm. From the experiment we understand that when the pump flow rate increase, the pump pressure head will increase as well. If a graph is plotted, the graph would be increasing linearly. For the power consumed, the torque is directly proportional to the power input. As the torque reading increase, the power

input will increase. When a graph of efficiency vs flow rate is plotted, we can see that the increment if the flow rate will eventually cause the efficiency to increase as well. MUHAMMAD SYAFIQ BIN ROSNI 15214 DISCUSSION After analyzing & looking through all available data and graphs associated, these are the summary based on each graph obtained : 1. Pressure head vs. Pump flow rate As shown in the graph, as the flow rate increases, the pressure head varies respect to different speed. The trend is similar between those three types of speed, which is increases as the flow rate increases. Higher speed have higher magnitude of flow rate respectively. 2. Efficiency vs. Pump flow rate Those three lines are nearly directly proportional but each one has different magnitude. When speed is 1200rpm at its highest flow rate, it has highest efficiency among all. We can assume at this speed, highest amount of energy is conserved during in and out of the pump. Means that, less energy loss.

SOURCE OF ERROR A lot of error has been identified which contributes to inconsistency in results obtained. 1st of all, the water or fluid speed is not constant for each round of experiment. this gives different result and thus, bringing further from theoretical values or results. 2nd, error in equipment used. Some defects in equipment may cause high amount of energy loss and inconsistency when taking readings. 3rd, human error when taking readings. Observation may be obstructed and thus, affecting the results taken. MODIFICATION Modification can overcome error that causes the faulty of the result. In order to get more accurate result, firstly we need to overcome parallax error. Make sure our eyes are perpendicular to the reading scale of the gauge to avoid parallax error. This modification will make the data collected to be more accurate. Next we need to let the machine run for a while after adjusted the speed. This to make sure the data collected is more accurate. Next, we need to make sure the speed of the water is constant so that the data collected is more accurate. This is because when the speed of the water is not constant, the pressure is also keep on changing and it’s hard to get the exact pressure. When this problem is overcome, data

collected will become easier. Vibration can be overcome by running the machine for a while until it stabile. Use absorber also can make the machine less vibrate and will increase the efficiency of the machine. CONCLUSION Pressure head, flow rate, power consumed and efficiency all of them have distinct relationship among them especiall efficiency. Different pressure head, flow rate, and power consumed gives effect to efficiency. Highest efficiency is crucial when comes to real life situation such as industrial sector.