62
ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: Dr. Cyders, 294A Stocker, [email protected] Dr. Ghasvari, 249B Stocker, [email protected] Spring 2014 1

Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

  • Upload
    vodan

  • View
    229

  • Download
    7

Embed Size (px)

Citation preview

Page 1: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

ME 4880 Experimental Design Lab

Centrifugal Pump Performance Experiment

Instructors:

Dr. Cyders, 294A Stocker, [email protected]

Dr. Ghasvari, 249B Stocker, [email protected]

Spring 2014

1

Page 2: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Part I. • General topics on Pumps • Categories of Pumps • Pump curve • Cavitation • NSPH

Page 3: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Pumps

– Basic definitions to describe pumps and pumping pipe circuits

– Positive displacement pumps and centrifugal pumps

– The ‘Pump Curve’

– Net Positive Suction Head

Page 4: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Pump analysis: energy equation

• Shaft work delivered by pump is translated into a pressure rise across the pump: P2 > P1

• How does hpump vary with Q? – Typically data is gathered from experiments by

manufacturer and is presented in dimensional form (pump curve)

2 2

1 1 2 21 2

2 2friction pump

P V P Vz z h h

g g g g

1 2

Q

Page 5: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Definitions in a typical pump system:

• Liquid flows from the suction side to the discharge side

• Suction head is head available just before pump, hs:

• Discharge head is head at the exit from pump, hd:

• Pump head, hp:

= head required from pump • Flow rates affect terms hfd & hfs

2 2

1 1 2 21 2

2 2friction pump

P V P Vz z h h

g g g g

ss s fs

Ph z h

g

dd d fd

Ph z h

g

p d sh h h

Page 6: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Positive Displacement Pumps

• Properties of a PD pump: – Pumps fluid by varying the dimension of an inner chamber.

Volumetric flow rate determined size of chamber + RPM of pump.

– Nearly independent of back pressure. • Application for metering fluids (example, chemicals into a process,

etc.)

– Develops the required head to meet the specified flow rate • Head limit is due to mechanical limitations (design/metallurgy).

Catastrophic failure at limit. • High pressure applications

– Able to handle high viscosity fluids. – Often produces a pulsed flow

Page 7: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Types of Positive Displacement Pumps

A. Reciprocating piston (steam pumps)

B. External gear pump

C. Double-screw pump

D. Sliding vane

E. Three lobe pump

F. Double circumferential piston

G. Flexible tube squeegee

H. Internal gear

Page 8: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Positive Displacement Pumps

Page 9: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Centrifugal pumps

• Characteristics – Typically higher flow rates

than PDs. – Comparatively steady

discharge. – Moderate to low pressure

rise. – Large range of flow rate

operation. – Sensitive to fluid viscosity.

Page 10: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Efficiency of centrifugal pumps: 2 2

1 1 2 21 2

2 2friction pump

P V P Vz z h h

g g g g • From the energy

equation, pumps increase the pressure head

• The power delivered to the water (water horse power) is given by

• The power delivered by the motor to the shaft (breaking horse power) is given by

• Therefore, efficiency is:

PH

g

wP gQHwP Q P

bhpP T

w

BHP

P gQH

P T

Note: 1HP = 746W

Page 11: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Centrifugal pumps – pump curves • Real pumps are never ‘ideal’ and the

performance of the pumps are determined experimentally by the manufacturer and typically given in terms of graphs or pump curves.

• Typically performance is given by curves of: • Head versus capacity • Power versus capacity • NPSH versus capacity

– As Q increases the head developed by the screen decreases.

– Maximum head is at zero capacity – The maximum capacity of the pump is at the point where

no head is developed.

Page 12: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Centrifugal pumps – Sample Pump Curve

• 3500 is the RPM • Impeller size 6¼ to 8¾ in. are shown • Maximum efficiency is ~50%.

– Note that pumps can operate at 80-90% eff.

• Maximum normal capacity line – Should not operate in the region to the right

of the line because pump can be unstable.

• Semi-open impeller – Max sphere 1¼” – This pump is designed for slurries /

suspensions and can pass particles up to 1¼”. This is why efficiency is relatively low.

• Motor horse power. – Remember to correct for density using

previous equation

• Operating line (system curve) – This is dependent on the system you are

putting the pump into. It is a plot from the energy equation.

– That is, analyze the system to determine the pump head required as a function of flow rate through the pump … This will form the system line.

2

22 1

2 1 2

42

pump mD

P P L QH z z f h

g D g

Page 13: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Pump cavitation and NSPH

• Cavitation should be avoided due to erosion damage to pump parts and noise.

• Cavitation occurs when P < Pv somewhere in the pump

• Since pump increases pressure, to prevent cavitation we ensure suction head is large enough compared to vapour pressure Pv

• Net positive suction head

• Often we evaluate NPSH using energy equation and reference values – don’t measure Pinlet

s vs fs

P PNPSH z h

g

Page 14: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

NSPHrequired

• Manufacturers determine conservatively how much NPSH is needed to avoid cavitation in the pump – Systematic experimental

testing

• NSPHrequired (NPSHR) is plotted on pump chart – Caution: different axis scale

is common – read carefully

• Plot NPSH vs NSPHrequired to give safe operating range of pump

Q Qmax

Page 15: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Part II. • Dimensional analysis • Affinity Laws

Page 16: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Dimensionless pump performance

• Previous part: everything dimensional

– Terminology used in pump systems

– Pump performance charts

– NPSH and avoiding cavitation (NPSH vs NPSHR)

• This part :

– Discuss how centrifugal pumps might be scaled

– Best efficiency point

– Examples

Page 17: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Dimensionless Pump Performance

• For geometrically similar pumps we expect similar dimensionless performance curves

• Dimensionless groups?

– Capacity coefficient

– Head coefficient

– Power coefficient

– Efficiency

– NPSH?

• What to use for n (units 1/time): rad/s (), rpm, rps

3Q

QC

nD

2 2H

gHC

n D

3 5

bh

P

PC

n D

H QC C

C

2 2NPSH

g NPSHC

n D

Page 18: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Dimensional Analysis

• If two pumps are geometrically similar, and

• The independent ’s are similar, i.e., CQ,A = CQ,B

ReA = ReB

A/DA = B/DB

• Then the dependent ’s will be the same CH,A = CH,B

CP,A = CP,B

Page 19: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Affinity Laws

• For two homologous states A and B, we can use variables to develop ratios (similarity rules, affinity laws, scaling laws).

• Useful to scale from model to prototype • Useful to understand parameter changes, e.g.,

doubling pump speed.

3

,,

A

B

A

B

A

BBQAQ

D

D

Q

QCC

Page 20: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Dimensional Analysis: ideal situation

• If plotted in nondimensional form, all curves of a family of geometrically similar pumps should collapse onto one set of nondimensional pump performance curves

• From this we identify the best efficiency point BEP

• Note: Reynolds number and roughness can often be neglected

Page 21: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Dimensionless Pump Performance

• In reality we never achieve true similarity – E.g. manufacturers put different

impeller into same housing

– Following figure illustrates a typical example of 2 pumps that are ‘close’ to similar

• Note:

• See that at BEP: max = 088

• From which we get

• From which you can calculate Q, H, NPSH, P

* * * *, , ,Q H HS xC C C C

Page 22: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Part III. • More on Centrifugal Pumps • Pump selection

Page 23: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Pump selection

• Previous part :

– Other types of pumps

– Centrifugal and axial ducted

– Pump specific speed

• This part Non-dimensional Pi Groups for pumps – Application to optimize pump speed (BEP)

– Scaling between pumps

3Q

QC

nD

2 2H

gHC

n D3 5

bh

P

PC

n D

2 2NPSH

g NPSHC

n D

Page 24: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Dynamic Pumps

• Dynamic Pumps include

– centrifugal pumps: fluid enters axially, and is discharged radially.

– mixed--flow pumps: fluid enters axially, and leaves at an angle between radially and axially.

– axial pumps: fluid enters and leaves axially.

Page 25: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Centrifugal Pumps

• Snail--shaped scroll

• Most common type of pump: homes, autos, industry.

Page 26: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Centrifugal Pumps

Page 27: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Centrifugal Pumps: Blade Design

Page 28: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Centrifugal Pumps: Blade Design

Vector analysis of leading and trailing edges.

Page 29: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Centrifugal Pumps: Blade Design

Blade number affects efficiency and introduces circulatory losses (too few blades) and passage losses (too many blades)

Page 30: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Axial Pumps

Open vs. Ducted Axial Pumps

Page 31: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Open Axial Pumps

Propeller has radial twist to take into account for angular velocity (=r)

Blades generate thrust like wing generates lift.

Page 32: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Ducted Axial Pumps

• Tube Axial Fan: Swirl

downstream

• Counter-Rotating Axial-

Flow Fan: swirl removed. Early torpedo designs

• Vane Axial-Flow Fan: swirl removed. Stators can be either pre-swirl or post-swirl.

Page 33: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Pump Specific Speed

Pump Specific Speed is used to characterize the operation of a pump at BEP and is useful for preliminary pump selection.

Page 34: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Centrifugal pumps-specific speed

Proper Lazy

'17,182s sN N

Use Dimensionless ‘specific speed’ to help choose. Dimensionless speed is derived by eliminating diameters in Cq and Ch at the BEP.

12

34

1/ 2*

*'

3/ 4*

*

Q

s

H

n QCN

C gH

12

3/ 4

( / min)

( )s

Rpm GalN

H ft

Page 35: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

What we covered:

• Characteristics of positive displacement and centrifugal pumps

• Terminology used in pump systems

• Head vs flow rate: pump performance charts

• NPSH and avoiding cavitation (NPSH vs NPSHR)

• Examples

Page 36: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

What we covered:

• Today we

– Developed dimensionless pump variables

– Extrapolate existing pump curve to different pump speeds, diameters, and densities

– Examples

3Q

QC

nD

2 2H

gHC

n D

3 5

bh

P

PC

n D

2 2NPSH

g NPSHC

n D

Page 37: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

What we covered

• Today we:

– Examined axial, mixed, radial ducted and open pump designs

– Used specific speed to determine which type is optimal

Page 38: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Part IV. • Lab procedure

• Venturi Measurements

• Summary of equations and calculation way

• Preparing graphs

Page 39: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Lab Objectives

• Understand operation of a dc motor

• Analyze fluid flow using

– Centrifugal pump

– Venturi flow meter

• Evaluate pump performance as a function of

impeller (shaft) speed

– Develop pump performance curves

– Assess efficiencies

Page 40: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Lab Set-up

Motor

E I

T

Pump

Water Tank

Venturi

P( )

ValvePaddle meter

Dynamometer

Pin

Pout

Page 41: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

D.C motor

Figure 1. dc motor (howstuffworks.com)

•Armature or rotor

•Commutator

•Brushes

•Axle

•Field magnet

•DC power supply

Page 42: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Centrifugal pump operation

• Rotating impeller delivers energy to fluid

• Governing equations or Affinity Laws relate

pump speed to:

– Flow rate, Q

– Pump head, Hp

– Fluid power, P

Page 43: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.000 0.002 0.004 0.006 0.008 0.010 0.012

0

2

4

6

8

10

12

14

16

18

20

22

24

0.000 0.002 0.004 0.006 0.008 0.010 0.012

0

2

4

6

8

10

12

14

16

18

20

22

24

pump head 1709 rpm

Flow Rate (m3/s)

Head

(m

)

0

200

400

600

800

1000

1200

1400

fluid power 1709 rpm

flu

id p

ow

er

(W)

operating point

pump efficiency 1709 rpm

pu

mp

eff

icie

ncy,

system load - head

Page 44: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Pump Affinity Laws

• N Q

• N2 Hp

• N3 P

2

1

3

2

1

2

12

2

1

2

1

2

1

P

P

N

N

H

H

N

N

Q

Q

N

N

p

p

Page 45: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Determination of Pump Head

12

21

22

2ZZ

g

VV

g

PPH inout

p

g

PPH inout

p

Page 46: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Determination of Flow Rate

• Use Venturi meter to determine Q

• Fluid is incompressible (const. )

Q = Vfluid Area

Page 47: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Venturi Meter

• As V , kinetic energy

• T = 0

• Height = 0

• Pv or P

Page 48: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Calculate Q from Venturi data

22VACQ d

• V1 = inlet velocity

• V2 = throat velocity

• A1 = inlet area

• A2 = throat area

Page 49: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Throat Velocity

22

22

11

21

22Z

g

P

g

VZ

g

P

g

V

0Z2

21

221 BV

A

AVV 21 PPP

),,(2 BPfV

vAmm21

..

Page 50: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Discharge Coefficient

eDd

R

BC 53.6907.0

1

2

D

DB

11DVReD

22

1

221 BV

A

AVV

Page 51: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Solve for Q

• Use MS EXCEL (or Matlab)

• Calculate throat velocity

• Calculate discharge coefficient using

Reynold’s number and throat velocity

• Calculate throat area

• Solve for Q

Page 52: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Power and Pump Efficiency

• Assumptions

– No change in elevation

– No change in pipe diameter

– Incompressible fluid

– T = 0

• Consider 1st Law (as a rate eqn.)

0Q

12

21

2212

2

1ZZgVVhhmWQ

Page 53: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Pump Power Derivation

Pvuh

vPuvPumhhmW 112212

12 PPvmW

QVAvm

12 PPQW

Page 54: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Efficiencies

EI

PPQ

EI

T

T

PPQ

input

output

overall

motor

pump

12

12

Page 55: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Summary of Lab Requirements

• Plots relating Hp, P, and pump to Q

• Plot relating P to pump

• Regression analyses

• Uncertainty of overall (requires unc. of Q)

• Compare Hp, P, Q for two N’s

– For fully open valve position

– WRT affinity laws

Page 56: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Flow Rate (m3/s)

Pu

mp

He

ad

(m

) 905 rpm 1099 rpm 1303 rpm 1508 rpm

1709 rpm

Page 57: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

905 rpm 1099 rpm 1303 rpm 1508 rpm

Flow Rate (m3/s)

Po

we

r D

ele

ve

red

to

Flu

id (

W)

1709 rpm

Page 58: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

pu

mp

eff

icie

ncy

Flow Rate (m3/s)

905 rpm 1099 rpm 1303 rpm 1508 rpm

1709 rpm

Page 59: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Pu

mp

Eff

icie

ncy

pump power delivered to fluid (W)

905 rpm 1099 rpm 1303 rpm 1508 rpm

1709 rpm

Page 60: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Start-up Procedure 1. Fill pvc tube with water (3/4 full)

2. Bleed pump

3. Switch breaker to “on”

4. Push main start button

5. Make sure variac is turned counterclockwise

6. Make sure throttle valve is fully open

7. Turn lever to “pump”

8. Push “reset” button

9. Push “start” button

10. Adjust variac to desired rpm using tach.

Page 61: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Pump lab raw data

Shaft speed (rpm)

DC voltage (volts)

DC current (amps)

Inlet Pressure (in Hg)

Outlet Pressure (kPa)

Venturi DP (kPa)

Dyna (lbs)

Page 62: Centrifugal Pump Performance Experimentfhegedus/VibrationMonitoring/Ali Parhizkar... · ME 4880 Experimental Design Lab Centrifugal Pump Performance Experiment Instructors: ... –Venturi

Shut-down Procedure

1. Fully open throttle valve

2. Turn variac fully counterclockwise

3. Push pump stop button

4. Turn pump lever to “off”

5. Push main stop button

6. Switch breaker to “off”