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Ozmara Angélica Ortiz OrozcoOzmara Angélica Ortiz Orozco

PUMP PUMP CALCULATIOCALCULATIO

NN

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AgendaAgenda

• Theorical FrameworkTheorical Framework• Sizing a Pump:Sizing a Pump:

– AFT FathomAFT Fathom– JEPump.exeJEPump.exe– Theorical CalculusTheorical Calculus

• ComentariesComentaries

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REMEMBERING…REMEMBERING…

Suction AnalysisSuction Analysis

Static suction lift decreases

NPSHA because the pump must work

against gravity

Static suction head increases

NPSHA because gravity helps pull liquid into the pump

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ParametersParameters::QQ11 o W o W11 FlowFlow

VV11 VelocityVelocity

PP11 PressurePressure

ρρ11 DensityDensity

AA11 AreaArea

Heat or Work SuppliedHeat or Work Supplied WWf1f1

ZZ11 HeightHeight

Energies Involved:

1. Internal Energy2. Potential Energy3. Kinetic Energy4. Pressure Energy5. Gravity

Bernoulli Equation:

144: Correction Factor for English units

Lhg

VPZ

g

VPZ

22

22

2

22

21

1

11

Transform the mechanical energy to Kinetic energy, generating Pressure and Velocity in the fluid.

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Example: Example: Sizing a PumpSizing a Pump

A pump is to be used to transfer water from a supply reservoir to a holding reservoir at the top of a A pump is to be used to transfer water from a supply reservoir to a holding reservoir at the top of a hill. hill.

The system consists of a supply reservoir, a pump, a discharge reservoir, and two pipesThe system consists of a supply reservoir, a pump, a discharge reservoir, and two pipes

Pipe No.1: 3 meters long.Pipe No.1: 3 meters long.Pipe No. 2: 300 meters long.Pipe No. 2: 300 meters long.(Both pipes are 4 inch (10.2 cm ID), Steel, Schedule 40 pipes)(Both pipes are 4 inch (10.2 cm ID), Steel, Schedule 40 pipes)

Constant Properties are assumed.Constant Properties are assumed.Surface Pressure: 1 atmSurface Pressure: 1 atmSupply Tank elevation 3 metersSupply Tank elevation 3 metersDischarge Tank elevation: 60 metersDischarge Tank elevation: 60 meters

The pipes for both reservoirs connect to the reservoirs at a depth of 3 meters.The pipes for both reservoirs connect to the reservoirs at a depth of 3 meters.

What is the head requirement for a pump to supply flow in this system at 115 m3/hr?What is the head requirement for a pump to supply flow in this system at 115 m3/hr?

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3 m

60 m

Calculus manually:Calculus manually:

ConsiderationsConsiderations

FluidFluid WaterWater

TemperatuTemperaturere

21 °C21 °C

Vapor Vapor PressurePressure

0.359 Psi (0.81 ft)0.359 Psi (0.81 ft)

PatmPatm 1 atm (33.977 ft)1 atm (33.977 ft)

KtotalKtotal 2525

Inner Inner diameterdiameter

4.026 in4.026 in

FlowFlow 115 m3/hr 115 m3/hr (506.3298 GPM)(506.3298 GPM)

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Formulas involved:Formulas involved:

D

Lfk

kK

ZZhHd

KQh

dVd

QV

pipe

i

L

L

)(

Re

12

4

2

2

3960rel

L

Lvpatm

QHHp

ZhH

HHHsHNPSH

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AFT FathomAFT Fathom

Applied Flow TechnologyApplied Flow Technology• ModulesModules• PropertiesProperties• AssumptionsAssumptions

• Primary WindowsPrimary Windows

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Procedure:Procedure:

Step 1: Specify OutputStep 1: Specify Output• Output ControlOutput Control

– Title: “Sizing a Pump”Title: “Sizing a Pump”

• System PropertiesSystem Properties– AFT StandardAFT Standard– Water at 1 atm (add to model)Water at 1 atm (add to model)– 21 °C21 °C

Step 2: Build the ModelStep 2: Build the Model

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Procedure (continue)Procedure (continue)Step 3: Specifications of the objectsStep 3: Specifications of the objects

• 1.1. J1 Reservoir (Supply Tank) J1 Reservoir (Supply Tank)

– a. Name = Reservoira. Name = Reservoir– b. Elevation = 3 metersb. Elevation = 3 meters– c. Surface pressure = 1 atm.c. Surface pressure = 1 atm.– d. Pipe depth = 3 meters (entered on the "Pipe Depth & Loss Coefficients" tab)d. Pipe depth = 3 meters (entered on the "Pipe Depth & Loss Coefficients" tab)

• 2.2. J2 Reservoir (Discharge Tank)J2 Reservoir (Discharge Tank)

– a. Name = Reservoira. Name = Reservoir– b. Elevation = 60 metersb. Elevation = 60 meters– c. Surface pressure = 1 atmc. Surface pressure = 1 atm– d. Pipe depth = 3 meters (entered on the "Pipe Depth & Loss Coefficients" tab)d. Pipe depth = 3 meters (entered on the "Pipe Depth & Loss Coefficients" tab)

• 3.3. J3 Pump J3 Pump

– a. Type = Assigned Volumetric Flow (for sizing)a. Type = Assigned Volumetric Flow (for sizing)– b. Flow rate = 115 m3/hrb. Flow rate = 115 m3/hr– c. Elevation = 0 metersc. Elevation = 0 meters

Step 4: Run the ModelStep 4: Run the ModelStep 5: Check Out ResultsStep 5: Check Out Results

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Now that the pump Now that the pump head requirementhead requirement has been identified as has been identified as 116.3 meters116.3 meters at the design flow rate at the design flow rate of 115 m3/hrof 115 m3/hr, a pump of the correct size can be purchased to meet this requirement. Once the , a pump of the correct size can be purchased to meet this requirement. Once the actual pump has been identified, the pump characteristics can be added to the pump component by actual pump has been identified, the pump characteristics can be added to the pump component by adding the pump curve data to the pump junctionadding the pump curve data to the pump junction

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Adding the pump curve dataAdding the pump curve data

Pump Curve Data:Pump Curve Data:

122 meters @ 0 122 meters @ 0 m3/hrm3/hr

116 meters @ 115 116 meters @ 115 m3/hrm3/hr

76 meters @ 230 76 meters @ 230 m3/hrm3/hr

Curve Fit Order: 2Curve Fit Order: 2• After the curve After the curve

data is entered, data is entered, click the click the Generate Curve Generate Curve Fit Now button Fit Now button and then the OK and then the OK button.button.

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Procedure (continueProcedure (continue

Step 9. Re-evaluate the modelStep 9. Re-evaluate the modelExamine the Pump Summary in the General Output Section. The output (Figure 2.4) shows the pump Examine the Pump Summary in the General Output Section. The output (Figure 2.4) shows the pump operating at a flow rate of 114.7 m3/hr, and a head rise of 116.1 meters., which is acceptably close to operating at a flow rate of 114.7 m3/hr, and a head rise of 116.1 meters., which is acceptably close to the previous sizing calculationthe previous sizing calculation

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Change to the Graph Results window (e.g., using the Windows menu), and Change to the Graph Results window (e.g., using the Windows menu), and choose Select Graph Data. Here you can specify that a pump vs. system curve choose Select Graph Data. Here you can specify that a pump vs. system curve be created.be created.

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JEPumpsJEPumps

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Comparative Table ResultsComparative Table Results

NPSNPSHdHd

(ft)(ft)

dPdP

PumPumpp

(psia(psia))

HPHPVelociVeloci

tyty

(ft/s)(ft/s)

dPdP

suctiosuctionn

(psia)(psia)

dP/dP/100ft100ft

dPdP

dischadischargerge

(psia)(psia)

FathoFathomm

41.641.677

165.165.22

48.48.7777 12.7612.76 -4.3-4.3 5.725.72 167.5167.5

JEPumJEPumpp

39.739.7 164.164.44

48.48.88

12.7612.76 -4.3-4.3 5.725.72 168.8168.8

ManuManuallyally

41.741.744

172.172.0202

49.49.33

12.7512.75 -4.8-4.8 5.72*5.72* 167.02167.02*: Crane B-17

PUMP PIPES