Depumps Notes

Singapore – June 2012 Singapore – June 2012

Agenda

1. Pump Configurations & Installations

2. Variable Speed Pump Basics

3. ASHRAE 90.1 requirements for

Variable Speed Pumping and

Balancing

4. All Variable Speed Chilled Water

Plant Control Methodology


Pump types

Vertical Inline End Suction

Horizontal Split Case


Vertical InLine - 14x14x15 150hp

Suction

Diffuser

Triple Duty

Valve

• Easy to install

Pipe mounted directly into

piping - Smallest footprint

is inherent

• Eliminate cost of

flex connections

and inertia bases

• Minimal

commissioning

costs

• Self contained unit

• No site grouting costs

• No alignment costs or

concerns

• No lubrication

required or seal

adjustments

necessary

• No Pump Bearings


4300 - 14x14x15 150hp

Pressure

Gauge

Sight Glass & Filter


Vertical Inline – Grooved Systems

• 20x20x19 Pump

• Pipe Line Mounted & Supported

• Inertia Base Not Required

• Flex Connectors Not Required

• No Alignment Required

• 1 Mechanical Seal to Maintain


Primary CHW Pumps


Condenser Pumps


8

GuangHui Project Taiwan 60 000 tons of refrigeration

46-16x16x15 300 hp

23 -3000 ton Chiller installation

Dedicated Pump For Chillers


Dedicated Pump - Chillers


10

Ford Plant in Mexico


Dual Pumps – Typical Mounting

Seismic Installation


Flotrex & Suction Guides


Triple Duty Valve

•Drip-tight Shut Off Valve

The Armstrong Flo-Trex valve is designed

and tested for drip-tight isolation at

150% of maximum working pressure.

•Flow Throttling Valve

The Armstrong Flo-Trex valve uses a plug and disc

design which is the most effective valve type for

combining throttling of flow and isolation. Other

design valves may be effective for throttling or

isolation, but not both

•Non-slam Check Valve

The Armstrong Flo-Trex valve incorporates a spring

closure design that closes the valve in a controlled

manner, protecting the valve from slamming due to

a reversal in flow caused by gravity or recirculation

from a parallel pump.

•Convertible Body Design

The Armstrong Flo-Trex convertible body design

permits the valve to be changed on-site from

straight to angle configuration


Suction Guide

•90˚Elbow

Mounting the Suction Guide on any pump

Suction turns the piping 90°, replacing an

elbow. In addition, the Suction Guide can be

rotated to any position allowed by the pump

suction bolts, from vertical to horizontal.

•Inline Strainer

The stainless steel strainer has free area of at least

250% of pipe sectional area. A disposable finemesh

strainer is installed for start-up.

•Reducing Elbow

The Suction Guide connects same size piping to

the pump suction, but can also connect to inlet

piping one size larger than the pump suction,

eliminating a reducing elbow.

•Guide Vanes

Flow stabilizing vanes on the outlet allow the Suction

Guide to bolt directly to the pump, saving the space

and cost of a long straight pipe


Vertical Inline – Mechanical Seal Removal


End SuctionBase Mounted

Pump

A comprehensive range of single stage,

end suction, radially-split centrifugal

pumps designed for a wide variety of

applications. Features self-venting

casing to prevent air binding, heavy duty

bearings that are sealed and lubricated

for life, back pull-out bearing frame for

easy removal, and self-lubricating

mechanical seal to prevent liquid

seepage. Available in bronze fitted, all

bronze and all iron construction.


4030 Base Mounted Pump – Cross Sectional View

Single spring mechanical seal with O-ring

mounted silicone carbide seat provides

leak-proof operation throughout pump range.

Bearing assembly

two anti-friction bearings,

permanently lubricated,

carry design loads with

minimum.

A heavy fabricated steel baseplate, rigidly constructed to ANSI/HI 1.3.5

standards, provides for proper alignment of pump and motor.

Base supported casing

eliminates need to support

casing when bearing

assembly is removed

Stainless steel

Shaft Sleeve

Dynamically

balanced

cast bronze or

iron impeller

Radially split casing provides pull out design

that allows removal of bearing assembly and

impeller without disturbing pipe connections.

Drilled and tapped connections

for gauges and drain.

ANSI flanges.

Top centerline discharge

ANSI style casing, self

venting to eliminate

pump vapor lock

Gasket, non-asbestos,

confined as

recommended by ANSI.


Base Mounted Pumps – Base, Grouting & Alignment

Grouting

Alignment

Base


Base Mounted Pumps – Flex Connectors

Flexible Connectors

Straight Section

5 to 10 Pipe Dia.


Hillcrest Recreation Center


Base Mounted Pumps – Concrete Base & Spring Isolators

Spring Isolators

Form for Concrete

Base


COMMERCIAL PUMPS Model 4600 HSC

The Series 4600 is the state of the art

Horizontal Split Case pump – based on the

"Tilted Parting" concept to minimize

turbulence at the eye of the impeller by its

straight laminar approach, thus

maximizing efficiency. This also results in

the lowest profile and minimum floor

space of any HSC pump, lowering

installation costs. Cartridge seals and

bearing removal nuts ensure ease of

maintenance.


Double Suction Pumps

require approx. 30%

more space

Inertia Bases

Alignment

Grouting of bases

Vertical In Lines cost

less



Typical HSC Installation


Variable Speed Pumping

Presented By Rocco Logozzo – S.A.Armstrong Limited


Vertical inline pump

How a pump works


Centrifugal Pump Characteristics

Flow

Efficiency

Power

Head Design Duty

BHP = GPM x Head (ft) ______________

3960 x Pump Eff. %

KW = BHP x .746


For conditions of 1000 USGPM at 100 Ft a 4300 6x6x11.5 may be

used with a 40 HP motor – 11.36” impeller diameter

Note that this is maximum non-overloading

impeller diameter for 40 HPmotor

Pump Basics – Pump Selection


Why Variable Speed Pumping?


HP

Speed/Flow

Energy used

at rated speed.

Nominal

Power

Nominal

flow

The power consumed = Speed ³

The Cube Law


22 Kw pump at 50% of rated speed

Power = 22 Kw x (0.5 x 0.5 x 0.5)

Power = 2.75 Kw (12.25% nominal) Energy Used

50% flow

12.75%

50%

Kw.

Speed/Flow

Nominal

Power

Nominal

flow

The power consumed = Speed ³

The Cube Law


Fixed Speed Pumping


Typical Secondary Pumping Loop (Constant Flow)

Fixed Speed Pumping


DESIGN CONDITIONS: 1000 GPM @ 100 Feet 63 L/s @ 30.5 Meters

Fixed Speed Pumping


Constant Flow System to Variable Flow System

Fixed Speed Pumping


OPERATION POINT: 500 GPM @ 122 Feet 31.54 L/s @ 37 Meters

Power Savings: Flow @ 50% (Constant Speed Pump)


Power Savings: Flow @ 50% (Constant Speed Pump)

Usgpm Ft. HdPump

RPMPower HP Efficiency

1000 100 1760 31.3 80.7

500 122 1760 22.5 68.9

Power Savings: 28%


Typical Strategy 1 – Constant head at

pump for Secondary Pumping Loop


Basic Requirements

1. Pumps

2. VFD’s

3. DPS (Differential Pressure Sensor)

4. DPS Set Point *

*Depends where it’s located in the

the system

If its close to the pump’s supply &

Return, the set point would be same as

the pump’s differential pressure.


OPERATING POINT: 500 GPM@ 100 Ft

Flow @ 50% DP Sensor across pump (100 Ft)

DP Set Point = 100 ft (298 KPA


Additional Savings over riding pump curve: 22%

Power Savings: Flow @ 50% DP Sensor across pump

Usgpm Ft. HdPump


1000 100 1760 31.3 80.7

500 100 1599 17.5 72.0

Power Savings: 44%


Typical Strategy 2 – Constant Head at Index

Point for Secondary Pumping Loop


What is the DP set point

if the sensor is located further

away from the pumps?


OPERATING POINT: 500 GPM @ 63 ft 31.54 L/s @ 188 KPa

Flow @ 50% DP Sensor across coil & CV


Additional Savings over maintaining plant DP: 42%

Power Savings: Flow @ 50%

DP Sensor across coil & CV


Usgpm Ft. HdPump


1000 100 1760 31.3 80.7

500 63 1288 10.2 78.2

Power Savings: 67%


Typical Strategy 3 – DP Sensor across the Control Valve

DP Sensor located at the farthest point

sometimes called the Index leg

Problems could result where coils are

under flowed during part Load

How do we solve or mitigate this

Problem?

1) Multiple sensors

2) Manual Balancing with DP Controller

3) PICV Valves


Flow @ 50% DP Sensor across CV

OPERATING POINT: 500 GPM @ 48 FT


Power Savings: Flow @ 50% DP Sensor across CV (30 ft)

Usgpm Ft. HdPump


1000 100 1760 31.3 80.7

500 48 1141 7.5 80.4

Power Savings: 76%


Power Savings - Summary


System

Type

Pump

Speed

Sensor

LocationUsgpm Ft. Hd

Pump


Power

Savings

Constant Constant None 1000 100 1760 31.3 80.7 0%

Variable Constant None 500 122 1760 22.5 68.7 28%

Variable Variable Pump 500 100 1599 17.5 72.0 44%

Variable Variable Load&CV 500 63 1288 10.2 78.2 67%

Variable Variable Valve 500 48 1141 7.5 80.4 76%


6.7.2.3 System Balancing

• “All HVAC systems shall be balanced”

• “Written balancing report for conditioned areas exceeding 5,000ft2

(500m2)”

• “Hydronic Systems shall be Proportionately Balanced in a manner to

first minimize throttling losses”

6.7.2.3.3 Hydronic System Balancing


Unbalanced System

• OA = 100°F

• A needlessly large volume

is pumped. This increases

the energy consumption at

both the pump and chiller

• The return water

temperature is quite low.

This reduces the efficiency.

It also reduces the capacity

of the chiller to 79%

• A 250 Ton chiller is used,

but it supplies only 197.5

Ton (79%).

# 1

# 2

# 3

# 4

# 5

# 6

* 790 GPM

** 51°F

*** 250 TON CHILLER

197.5 CONTROLLER

T = 6°F 45°F

15

25

50

100

200

400

65

63

64

59

61

55

58

51

54

48.5

51

93°F / 30% BTU

89°F / 45% BTU

83°F / 70% BTU

75°F / 100% BTU

70°F / 120% BTU

65°F / 140% BTU

F

F

F

F

F

F

GPM

T = 3.5°F

T = 6°F

T = 10°F

T = 14°F

T = 18°F

T = 20°F

CHILLER

79%


Balanced System

• OA = 100°F

• The correct volume is

pumped and no more

pump energy than

necessary is used

• The “design” return water

temperature is

accomplished. Efficiency is

improved. 100% capacity

can be provided.

• The capacity of the chiller

is utilized to 100%.

# 1

# 2

# 3

# 4

# 5

# 6

* 600 GPM

** 55°F

*** 250 TON CHILLER

(250) CONTROLLER

T = 10°F

100

100

100

100

100

100

75°F / 100% BTU

75°F / 100% BTU

75°F / 100% BTU

75°F / 100% BTU

75°F / 100% BTU

75°F / 100% BTU

°F

°F

°F

°F

°F

°F

GPM 55

55

55

55

55

55 T = 10°F

T = 10°F

T = 10°F

T = 10°F

T = 10°F

T = 10°F

45°F

CHILLER

100%


Typical Strategy 3 – DP Sensor across the Control Valve

DP Sensor located at the farthest point

sometimes called the Index leg

Problems could result where coils are

under flowed during part Load

How do we solve or mitigate this

problem.

1) Multiple sensors or move sensor closer

2) Manual Balancing with DP Controller

3) PICV Valves


Differential Pressure Controller

Protect Control Valves from large differential pressure variations

experienced at varying load on the system

Good Control Valve Authority is maintained at part load


PICV Standard EQM control valve

PICV – Pressure Independent Control Valve


DE –IVS: Sensorless Pump Control & Design Envelope


Design Envelop HVAC Pumping

Pumping unit complete with motor integrated VFD

and controls

•Simply wire power as any pumping unit

• Motors will not overload – Controls allow max

motor nameplate current only

• Supplied with 208V, 230V, 380V, 460V or

575V, ODP or TEFC motors

• Available with Sensorless control

• Sensorless feature can be disabled &

controlled through an Pump Controller, or BAS

via all common communication protocols


Evolving

Brand1 Brand 2 Brand 3 Brand 4 Brand 5


Sensorless Pump & Motor Data


Sensorless Control

• Pump & VFD units are supplied with Sensorless

Control as standard, where available

• Sensorless Control may be switched at the factory [or

on-site] to another control strategy (BMS, Pump

Controller & remote sensor, etc)

• Keys to Sensorless Control are:

• Knowing where the pump is operating

• Knowing where the pump should be operating


Sensorless Control

• Knowing where the pump is operating

• How do we do that?


Pump curve derived from pump test


Flow / head requirements predict power & efficiency at rated speed

7500gpm at 45 m design

242.08hp at 86.83% efficiency


Flow / head predicted from power & speed

240.35bhp at 58.8Hz

indicates unit operating at 7500gpm at 45 m head


Design Envelope & Sensorless Control

• Knowing where the pump should be operating


Design Envelope IVS – Where it should operate …

A

B

Head

Flow

Min

. H

ead

System

Design Speed

A

B

Design Point

Minimum Head

Pumps

Cooling coil

Minimum Head equates to sensor setting at remote cooling coil in traditional system

Operating curve for

temperature control

with DP sensor


He

ad

Flow

Po

we

r

1

2

S1 S2

IVS Sensorless Pump Technology

Original System

Curve

Control Curve

S1 System Curve

S2 System Curve

P1

P2

Operating point is wherever pump

performance curve intersects

system resistance curve

Traditional Sensorless Control

Operating point is where pump

performance, system resistance and

control curves converge

Design Envelope – Sensorless Control

1 – Satisfied Flow & Head

Operating Point (S1 System

Curve)

P1 – Power at current flow &

head

S1 – Operating Speed pump

curve

2 – Satisfied Flow & Head

Operating Point (S2 System

Curve)

S2 – Operating Speed pump

curve

P2 – Power at current flow &

head

How do we get from 1 to 2?


Sensorless reduces speed and

chases equilibrium down control

curve until correct power & speed

ratio stabilizes at the new S2

system curve at 2 (S2 speed curve)

Operating point begins to move to

the left from 1 on S1 speed curve;

power reduces as it does so;

incorrect speed for the new power

value is recognized immediately;

System has CV modulating closed

resulting in a steeper S2 system

curve

Speed is stable at 1 until system

control valves (CV) modulate.

IVS Sensorless Pump Technology

Original System

Curve

Design Envelope – Sensorless Control

1

2

S1

S2

S1 System Curve

S2 System Curve

How do we get from 1 to 2?

Reverses as CVs open


Design

Point

As-Built

System

Motor

Power Line

Flow

Head

Pump Performance

Curve – Full Speed

PUMP

OPERATING

CURVE

Pump Performance

Curve – Design Speed

Minimum

System Pressure

(Typical Sensor

Setting)

System Curves –

Varies with load valves

Variable Speed Paradigm Shift Operating Point

As-built system:

System losses lower than

design – Motor cannot

overload. Operates at speeds

at or below motor current limit

Part load system needs –

Higher Efficiency than

constant speed. Lower

system pressure allows load

valves to operate in design

diff pressure range

Capability Envelope

Part

Load


Optimized capacity and motor power

• Impeller trim is optimized to the motor power

• Electronic load limiting

53.5 lps @ 27 m

18.5 kW vs. 22 kW traditional Savings in smaller

motor & controls

Motor/integrated

controls = € 350 or 9%

Power wiring = € 40

Harmonics = 16.6% reduction

A B Pump with Integrated VFD

(18.5 kW)

A C Traditional pump (22 kW)

A

C

BEP

B 15 kW

18.5 kW

22 kW

30 kW


Design Envelope advantages

Envelope selection reduces risk and cost

A

B

C A – Original design

B – 2nd

design

C – Final design


Energy Metering Capability

• Use the Integrated Controls as an energy meter for energy

measurement verification

kWh

readout


Flow Display

• Flow meter savings

• Ability for digital flow readout and communication to

BMS

• More capabilities coming in future

=


Wall Space Savings

No room

on wall

for multiple

VFDs


Reflected Wave Voltage

• If distance between the motor and the control is long, a

standing wave can form between the motor and control

• These waves can increase voltage at the motor terminals

causing the motor insulation and bearings to fail prematurely

• Locating the control with the motor will minimize this

problem


Harmonics - What is it?


Harmonic distortion

Fundamental

Summation of all

harmonic frequencies

Voltage distortion

may cause sensitive

loads to

malfunction

Current distortion

causes heat in the

transformer and its

power lines


Harmonic Causes


Harmonic Solutions


Harmonic distortion

• IEEE 519-1992 is a standard for limiting harmonics

• Measured at Point of Common Coupling (PCC)

• Stricter limits at higher voltage

• Prevent one customer from harming another

• Not intended to be applied within a user’s system


Harmonic Distortion

DC Link Reactors

built into IVS controls


Harmonic Distortion

• Variable Speed Drives with built-

in DC line reactors (equivalent to

5% AC line reactors)

• Other drives often need external

AC reactors (for 30 HP estimated

cost is $440): Mitsubishi, Hitachi,

Lenze/AC Tech, Yaskawa*,

Schneider, Eaton*, Siemens

* Some models only

External AC line reactors

5HP

125HP


Emission and immunity requirements

• Design Envelope IVS pumps include RFI filters to

ensure compliance to low emission and

immunity requirements EN61800-3 to the 1st

environment class CI (EN55011 unrestricted

sales class B).

• Wall-mounted drives often do not include these

and must be provided as an extra.


CHW Retrofit Installation


MLCC Project – Boiler Retrofit


King’s Yard Energy Centre / Olympic Park

London, UK

King’s Yard Energy Center


(HES with VFD vs. VIL with VFD

Wiring required between VFD

& Disconnect Switch & Motor

Mounting Bracket for VFD or

labor

Sensors or Installation

Required

Pump Inertia Base & Grouting

Installation

Alignment

Flex Connectors


“All-Variable” speed CHW plants


Primary – Secondary Pumping

C

H

I

L

L

E

R

C

H

I

L

L

E

RR eturn

Supply

Prim ary-

Secondary

C om m on

C

H

I

L

L

E

R

Load System

Source System

Prim ary Pum ps

D istribution System

Secondary Pum ps

Expansion System

• Common Pipe: Sizing is very Important

• Primary Pumps should not interact with

Secondary Pumps.

• Primary & Secondary side must

both be balanced


Variable – Primary Plant Layout


CHW Plant Basic Design

•Systems have operated for

decades in these modes.

•Traditionally equipment has

been sized for the best

efficiency at full load, or

design day conditions.

•Lets consider in detail the

operation of each of the

active components to better

understand how we could

save energy.

C ondenser

W ater Loop

C ooling Tow er

B uild ing Load

C hilled W ater LoopC hiller

C hilled W ater Pum p

C ondenser

W ater Pum p


CHW Plant Basic Design

C ondenser

W ater Loop

C ooling Tow er

B uild ing Load

C hilled W ater LoopC hiller

C hilled W ater Pum p

C ondenser

W ater Pum p

PID LOOP

PID LOOP

PID LOOP

Three PID Loops, behaving independently.

Capacity based sequencing.

Complex “reset” for strategies for light load.


Typical Chiller Design

Chiller (Refrigerant Loop)

Traditional constant speed

chillers have a fixed

speed compressor. The

expansion control valve

adjusts to modulate the

amount of refrigeration

work to achieve a

setpoint chilled water

supply temperature.

Typical Centrifugal Chiller Schem atic

C om pressor

Q (out to tower) 54F

44F

Q (in from load C H W )

Expansion Valve

Evaporator (Low T ,

Low P)

C ondenser

(h igh T , H i P )

Compressor bearings require

lubricant = oil management

systems

Heat energy moves naturally from a warm to cooler medium. To move heat

energy from a cooler medium to a warmer medium requires external “work”,

these devices are referred to as refrigeration devices, in our industry we know

them as Chillers.


“All-Variable” speed CHW plants

•Decrease Condenser Temperature – Condenser Relief

•Increase Chilled Water Supply – CHW Reset

•Stage Chillers, Pumps, Towers & Tower Fans


Variable Speed Devices are More Efficient at

Part Load by Design Intent

Variable speed Constant speed


"Natural Curve"

of VS Centrifugal Chiller

To achieve optimum

performance, chillers

should be

sequenced such that

the on-line chillers

operate as close as

possible to their

Natural Curve.

"Natural Curve" of a

Chiller


Cooling Tower Basics

Cooling Tower

• Rejects heat to atmosphere

through evaporative cooling

• Water air exposure maximized

by panels and fans

• Water molecules passing

through phase change to

vapor phase take heat energy

– molecules remaining in

liquid phase give up heat

energy to phase change =

cooling of liquid


Tower ETW Approach Temperature For 3 Tower Systems

The total power to fans

and pumps is the

same for the variable

speed and constant

speed systems at each

condition. Note the

improved approach by

slowing, not shedding

towers at low loads.

Natural Curve

Effect with Variable Flow and Fan Speed Tower


Optimizing All-Variable Speed Configurations:

The "Equal Marginal Performance Principle"

Trade off equipment loading in one device to pick up more load on

another, and achieve the same net “kW cooling” for lower kW electrical

input.


Equal Marginal Performance Principal


Demand Based Control

Singapore – June 2012

Plant KW/Ton measured in real time


Chiller and Tower recommendations

• The lower the turn down capability of each device, the

greater the efficiency of the plant.

• The variable speed chiller should have 70% load

turndown and includes serial communication (Lonworks,

BACnet, Modbus, or P Lan .

• The cooling towers must be selected for a 40% or greater

flow turndown

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