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)

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Elbow (692 gpm, 2 pipe diameters)

Water Velocity (feet per minute)

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Partially closed butterfly valve (685 gpm)

Water Velocity (feet per minute)

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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

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PUMP CAPACITY (gpm)

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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