Pump Station Design Session 1

8/6/2019 Pump Station Design Session 1

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Pump Station Design

Session 1 Overview of Checklist for PumpStation Design

By Teow Boo Koh

24 June 2011


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Some Key Items

1. Client requirements

Design standards /preferences

Manufacturers proven pump station design

Risk identified and clients buy in

2. Design Flows

Future flows

Min, Max flow, peaking factor

Guaranteed design flow

Acceptance test standards


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Some Key Items (cont)

3. Pumped Media

Critical to understand and characterise media

Media behaviour duty normal flow, extreme conditions

Impact on pump /motor sizing

4. Hydraulic Design

IHI Pump Intake Design 9.8

When do we need model testing

IHI guideline for model testing

pump flow > 2520L/s

Total pump station flow 6310L/s

Critical pump station

Remedial work cost > 10x model cost


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5. System Hydraulics

what is the dominant characteristics

Suction static head /discharge static head

Dynamic head

Minor fitting losses

Upper, lower and most likely system characteristics

NPSH required and NPSH available

Friction head loss calculation

Darcy Weisbach formula

Colebrook-White equation

Swamee-Jain approximation

Hazen-Williams equation


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6. Pump selection/mechanical design

POR/AOR

Test standard to AS2417(ISO 9906) Grade 1, 2 or Appendix A

Impeller size, media, speed

7. Electrical Design

Power margin

VSD harmonics, EDM, Loss

Motor cooling

Cable routing corridor


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8. Operation/Controls

Sensitivity of control, response time etc

Is your upstream or downstream capacity compatible

Rate of rise of inflow

9. Maintenance

Access

Provision of gantry crane, mono-rail or mobile crane

Lay down area

Access for flushing of pipework

10.Safety

Operator safety, confine space accessment


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Typical System Curve

S GRAPH OF SYSTEM CURVES - TE AWA AVENUE PUMP STATIONHIGH FLOW PUMPS - SINGLE PIPE FROM INDIVIDUAL PUMP TO END of FORESHORE - Post Tender Hydraulics

9.97

6.346.40

8.64

5.60

4.00

8.21

3425

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

0.0 500.0 1000.0 1500.0 2000.0 2500.0

000.0

500.0 4000.0

FLOW L/

HEA

Upper Bound Intake Water Level RL 9.2m System Curve For Guaranteed Duty Point at Level RL 10.0m

Lower Bound Intake Water Level RL 11.6m Guaranteed Duty Point

Duty Point 2 Duty Point

Amacan PB4 1200-870/450-20degrees 580RPM 1P KSB BEP

575 RPM BEP

487 RPM BEP

1


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Preferred perating Region

NSI I

Centrifugal Pump:

P R % to % B P

Vertical Pump

P R % to % SS < =

% to % SS>

R % to %

B P at ullImpeller

Dia


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Variable Speed Pump

Speed control

hen the operation speed is varying the operation data

change as well, according to the similarity rules

(= affinity rules), as stated below

low Q = Q (n n )

ead = (n n )

Power P = P (n n )

The affinity rules are not valid for the

NPS , for approximative calculations the

following equation can be used

NPS - value

NPS ~ NPS (n n ) x

x ~ , for calculation to higher speeds

x ~ , for calculation to lower speeds


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Acceptance test in accordance with N IS

Unit Symbol Grade Grade Annex

A %

Flow tQ 4,5 8 9

Head th 3 5 7

Pumpefficiency

tL -3 -5 -7

Guarantee design

point

Measured points


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Acceptance test in accordance with AS Part

ld BS : Part Class B tests :

Guarantee point


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Factory Test Curve BS Part Class C

test (IS )


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Cavitation NPS required

When the pump manufacturer develops the pumps NPSHrcurve, the calculated values are for conditions where the

expected head has fallen off by 3 % for that specific flow

rate. So if NPSHav = NPSHreq Incipent cavitation will occur

NPSHre is defined NPSHre = H0re - Pvap

where H0re is the measured inlet pressure when the

performance curve falls from a non cavitating curve, by > 3%(ISO 2548 -> 9906)

NPSH

Head

NPSHincNPSHre

0,97*Hdp

Hdp


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Typical Factory Test Curve and

NPS Test


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Suction nergy evel ( I - )


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NPS margin ratio recommendations

(ANSI I - )


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Pump Reference Plan ForTest Measurements

Especially important for NPSH

Datum


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Documents

Pump Station Design Session 1