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pumping
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BlaineHansonDepartmentofLand,AirandWaterResourcesUniversityofCalifornia,Davis
Deep Well Turbine
HowdoIdeterminetheconditionofmypump?
Answer:Conductapumpingplanttestandevaluatetheresultsusingthemanufacturerspumpperformancedata
Selftest:maybedifficulttodoHireapumpingplanttester
Eo =overallpumpingplantefficiency(wiretowater)includesefficiencyofelectricmotororengine
Q=flowrateorcapacity(gallonsperminute) H=totalhead(feet) IHP=inputhorsepowerofmotororengine 3960=conversionfactor
Deepwellturbine Pumpinglift measuredinsidethewellcasing Dischargepressurehead=pressure(psi)x2.31 Totalhead=pumpinglift+pressurehead
Boosterpump Pressuredifferencebetweenpumpdischargeandpumpintake Totalhead=pressuredifferencex2.31
Pumping Water Level
Pump
MotorDischarge Pressure Gauge
Discharge Pipe
Static or Standing Water Level
Pump Head
Ground Water
Ground Surface
Pumping Lift
Deep well turbine
PumpingLift
Pump Capacity
DischargePressure
Flowmeter Velocityaveraging:lesssusceptible
toerrorscausedbyadverseflowconditionsPropellermeter mostcommonCollinsmeterHallmeter
Pointvelocity:subjecttolargeerrorscausedbyadverseflowconditionsPaddlewheel
InstallationFlow
Propeller Flow Meter
8 to 10 Pipe Diameters 2 PipeDiameters
Installation Criteria
Velocity AveragingPoint Velocity
Control - no excessive turbulence
Water velocity (feet per second)
0 1 2 3 4 5 6 7 8
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Elbow (692 gpm, 2 pipe diameters)
Water Velocity (feet per minute)
0 1 2 3 4 5 6
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Partially closed butterfly valve (685 gpm)
Water Velocity (feet per minute)
-4 -2 0 2 4 6 8 10 12 14
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Electricmotors Powermeter IHP=Kw 0.746
Engines Dynamometer(BHP) notpracticalforgrowers(requirestraining) Fueluse IHP=qxK 2,545q=fuelconsumptioningallonsperhourK=139,000fordiesel,125,000forgasoline,91,000forpropane,84,600
forethanol
Causesofpoorefficiency Mismatchedpump ImproperlyselectedpumpChangesinoperatingconditions
Wornpump Surginginwell Cascadingwaterinthewell
Methodsofimprovingefficiency Replaceimproperlyselectedpumpormismatchedpumpswitha
properlyselectedpump Wornpumps ImpelleradjustmentRepairpumpReplacepump
Effect of Impeller Adjustment
Capacity (gpm)
Total Head (feet)
Overall Efficiency
(%)
Input Horsepower
Pump 1 Before 605 148 54 42 After 910 152 71 49 Pump 2 Before 708 181 59 55 After 789 206 63 65 Pump 3 Before 432 302 54 61 After 539 323 65 67 Pump 4 Before 616 488 57 133 After 796 489 68 144
EnergycostsarebasedonKilowatthoursofenergyused KwisrelatedtoIHP Hours operatingtime
Effectofadjustment Increasedflowrate Increasedpumpinglift? IncreasedIHP
EnergycostsincreasebecauseofincreasedIHPunlesspumpingtimeisreducedregardlessofhowmuchtheefficiencyincreased
Primarybenefitmaybetheincreasedflowrate
Before Pumpinglift=95feet Capacity=1552gpm IHP=83 Efficiency=45%
After Pumpinglift=118feet Capacity=2008gpm IHP=89 Efficiency=67%
Amismatchedpumpisoperatingproperlybutnotatitsmaximumpumpefficiency
Pumpshouldbereplacedwithonethatprovidesthesameflowrateandheadatitsmaximumefficiency
Capacity (gpm)
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Improperly Matched Pump
Matched Pump
Pumpingplantefficiencywillincrease
Inputhorsepowerdemandwilldecrease
Energysavingswilloccurbecauseofthereducedhorsepowerdemand
Recommendationsforelectricpumpingplants
Eo greaterthan60% nocorrectiveaction. 55%to60% consideradjustingimpeller. 50%to55% consideradjustingimpeller;consider
repairingorreplacingpumpifadjustmenthasnoeffect/ Lessthan50% considerrepairingorreplacingpump
0 100 200 300 400 500 600 700 800 900 1000 1100
PUMP CAPACITY (gpm)
0
50
100
150
200TOTAL HEAD (feet)
REPAIRED PUMPPumping Lift = 102 ftCapacity = 537 gpm
Input Horsepower = 28Overall Efficiency = 50%
Kwhr/af = 211
WORN PUMPPumping Lift = 45 ftCapacity = 624 gpm
Input Horsepower = 19Overall Efficiency = 39%
Kwhr/af = 123
LargeDifference
SmallDifference
Effectofpumpefficiencyandwellefficiency
Definition:actualspecificcapacity optimalortheoreticalspecificcapacity
Specificcapacity=pumpcapacity drawdowninthewell
Difficulttoestimatethewellefficiency
Pumping Water Level
Pump
Static or Standing Water Level
Ground Surface
Drawdown
Wellconstruction WellDesignDiameterOpeningsintothewell(openarea,location)Gravelpack
Welldevelopment Wellmaintenance