Motor/ Centrifugal Pump Performance

Jerry Bird Pumps

The University of Akron System DesignersAlan Jennings

Assisted by Mike Coe, Touby Khamphilapanyo & Kevin Tansey

2

Outline

• BackgroundPerformance Minor loss System Resistance

• ResultsHead Efficiency System Resistance

• The experiment

• The calculations

3

Pump Performance

• Chart shows consumers what to expect

• Pressure & flow rate for a pump speed

Souped up Curves!• Convenient Speeds• Constant Efficiency Lines• Constant Brake Horsepower Lines

4

Minor Loss Validation

• Major Losses due to Frictional Flow– Due to frictional, fully-developed flow

• Increases with fluid speed, roughness, viscosity, and reduced size

• Minor Losses – Due to friction with flow changes

• I.e. Elbows, pipe reductions, valves• Changes with geometry, size,

fluid speed, Reynolds's #

5

System Resistance Curve

• The required pump head for given flow rate

• Composed with system’s – Major & minor losses

– Elevation & pressure change

• Needed for sizing systems– Used with pump performance curve

Flow Coefficient

Head

Coe

fficie

nt

Operating Point

System Resistance Curve

6

Motor/Pump Performance Chart

Insert Chart Here

GNA6-1 1/2 Pump Proformance Curve

0

10

20

30

40

0 15 30 45 60 75

Flow (gpm)

Tota

l Hea

d (f

t)

1000 Rpm

1250 Rpm

1500 Rpm

1750 Rpm

0.3 BHP

0.5 BHP

0.7 BHP

70%60%50%40%

7

This pump

Pump Efficiency Comparison• Pump Maximum Efficiency 77%

– 1750 Rpm, 60 gpm, 34 ft head

• Maximum efficiency 86% • For similar pumps

8

Minor Losses Verified

Elbows, Flow Meter & Expansion

(4.4 to 5.3)

Globe Valve

(6.4 to 7.8)

Overall Resistance

5.2

4.8

Pump Performance Curve& System Resistance Curve

05

1015202530354045

0 15 30 45 60 75Volume Flow Rate (gpm)

Tota

l Hea

d R

ise

(ft) 1755

13081041SRC

9

Composing Chart• Planned and conducted experiment

– Head versus flow rate – Pressures for minor loss calculations– Electrical reading for power calculations

Pump Efficiency Curves

0%

15%

30%

45%

60%

75%

90%

0 15 30 45 60 75

Volume Flow Rate (gpm)

Inst

alle

d E

ffic

ienc

y

1755

1308

1041

Pump Performance Curve

05

1015202530354045

0 15 30 45 60 75Volume Flow Rate (gpm)

Tota

l Pre

ssur

e R

ise

(ft)

10

Dimensionless Analysis

• Head Coefficient function of Flow coefficient Machine Reynolds's #

Pump Performance Curve

0.00

0.03

0.06

0.09

0.12

0.15

0.000 0.002 0.004 0.006

Flow Coefficient (φ)

Hea

d C

oeffi

cien

t (ψ

)

ψ=-1454.5φ²+3.2173φ+0.1461R^2=.9982

11

Efficiency Coefficients VS Speed

0

50

100

150

200

250

300

350

1000 1200 1400 1600 1800RPM

Coe

ffic

ient

of

φ (

C2)

-35000

-30000

-25000

-20000

-15000

-10000

-5000

0

Coe

ffic

ient

of

φ²

(C1)

Phi

Phi^2

Poly. (Phi^2)

Poly. (Phi)

C2=10^-5*N^2+.1702*N-33.767

C1=-0.0153*N^2+17.833*N-15588

Pump Efficiency Curves

0%

15%

30%

45%

60%

75%

90%

0.0000 0.0020 0.0040 0.0060Flow Coefficient

Inst

alle

d E

ffici

en

cy

`

Dimensionless Analysis

• Efficiency function of Flow coefficient Machine Reynolds’s

#

η =C1 φ² +C2 φ

12

Dimensionless Analysis Results

Pump Efficiency CurvesBlue-measured, Gold-predicted

0%

15%

30%

45%

60%

75%

90%

0 15 30 45 60 75

Volume Flow Rate (gpm)

Inst

alle

d E

ffici

ency

1755130810411750150012501000

Pump Performance CurveBlue-measured, Gold-predicted

05

1015202530354045

0 15 30 45 60 75Volume Flow Rate (gpm)

Tota

l Pre

ssur

e R

ise

(ft) 1755

1308

1041

1750

1500

1250

1000

GNA6-1 1/2 Pump Proformance Curve

0

10

20

30

40

0 15 30 45 60 75

Flow (gpm)

Tota

l Hea

d (f

t)

1000 Rpm

1250 Rpm

1500 Rpm

1750 Rpm

0.3 BHP

0.5 BHP

0.7 BHP

70%60%50%40%Thank you!

Questions?

Calculations

UncertaintySensor SafetyEquipment