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AECOM IES Model

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Chiller System Optimisation

Series Counter Flow Configuration Variable Primary/Secondary CHW

System

Understanding Work/Lift Relationships

Wat

ersi

de L

ift

Com

pres

sor L

ift

Ref

riger

ant D

elta

-P

Saturated Condensing Temp

Saturated Evaporating Temp

Leaving Cond. Water Temp

Leaving Chilled Water Temp

Condenser Approach

Evaporator Approach

Compressor Lift = Refrigerant Delta PWork = Mass Flow Rate x Lift

ENTHALPY

PR

ES

SU

RE

HEAT REJECTED

HEAT ABSORBED

LIFT

SST

SCT

Sub-cooled Liquid

Superheated Vapour

“Traditional” Parallel System Configuration

Parallel Configuration 2 x 3550 kW Chillers

Waterside Lift (32.8 - 6) 26,8K

Building Load 100% (7100kW)2 x 3550 kW Chillers …..VSFChilled Water 15/6 Condenser Water 27.5/32.8

3550 kW

3550 kW

BypassDecoupler

Series Counter Flow Solution

BypassDecoupler

Building Load 100% (7100kW)4 x 1775 kW Chillers …..SCF with VPF/VSFChilled Water 15/6 Condenser Water 27.5/32.8

SCF with VPF/SCF Solution4x 1775 kW Chillers

Waterside Lift (32.8 - 6) 26,8K

Upstream Chiller (22.4 K)Downstream Chiller (24.2 k)

1775 kW 1775 kW

1775 kW 1775 kW

ApplicationsVSD Screw Series Counter flow

Both chillers designed to operate at 15/6˚C – 27.5/32.8˚C. (26.8 K W/Lift)

Upstream chiller 15 – 10.5˚C/ 30.15 – 32.8˚C. (22.35 W/Lift)

Downstream chiller 10.5 – 6˚C /27.5 – 30.15˚C (24.15 W/Lift)

Net Operating Savings of 5-15% with same equipment in Parallel Configuration!

15˚C

10.5˚C

6˚ C

27.5˚C

30.1532.8˚C

SCF Configuration Lift Reduction

Upstream

Downstream

SCF Plant room layout

SCF design utilises single pass vessels to avoid system pumping penalties

– Variable Speed Tri Rotor – Positive Displacement Compressor– Integrated Variable Speed (IEE519)– Refrigerant Cooled Drive– 0 ODP R134a (No Phase Out Date)– In Chiller Refrigerant Storage– ASME Heat Exchangers with Full

Waterbox Options– Variable Orifice– Seismic Compliant Option– Acceptable of CHW Flow Rate

Change of Up to 70% Design/Minute

23XRV Product Features

615 to 1935 kW (3870 kW SCF)

23XRV Reliabilityof Design

Semi hermetic-not required

No Shaft Seal Vanes Actuator Solenoids Slide Valve Purge

Reliability Through Simplicity - Fewer Moving PartsBalanced Tr-rotor design cancels load forces so

effectively, at AHRI conditions, the lowest

L10 life of any bearing in the compressor is over

50 years

Positive Displacement Compressor - No Surge- Speed Control directly load based (Not Ambient + Load)

Capacity Control

32MP Condenser pipingByass piping, isolation

valves not shownCH-1Lead

CH-2Lag

CH-1 Programmed as lead chiller, CH-2 programmed as lag chiller

CH-1 loads up until compressor speed = 80%.

At 80% compressor speed, CH-1 commands CH-2 to turn on. Since chillers are in series, pumpflows are already established.

CH-1 sends a demand limit signal to CH-2, thereby ensuring both chillers are running at thesame % of nameplate kW. CH-1 increases or decreases the demand limit to regulate T3 to set point.

At 35% compressor speed, CH-1 commands CH-2 to turn off.

If CH-1 becomes disabled, the on board controls rotate CH-2 as the lead chiller. CH-2regulates to the leaving temperature T3 via the 32MP sensor.

T1T2T3

Series Counter Flow

Hydronic Considerations VPF

Variable Primary Flow has synergistic effect with series evaporators.

VPFDS Lvg

100% 75% 50% 25%6.7 6.7 6.7 6.7

11.115.5

11.115.5

US LvgReturn

11.115.5

OffOff

With constant speed pumping delta T falls with load

Const. FlowDS LvgUS LvgReturn

100% 75% 50% 25%6.711.115.5

6.71013.3

6.78.911.1

6.7OffOff

Utilising VPF Series Configuration the leaving chilled water temperature of the upstream chiller stays warmer longer, increasing system efficiency compared to

constant primary flow

Carrier Chiller System Manager (CSM)• Chiller Set staging • Variable Primary CHW Flow Control • Cooling Tower Optimisation• Variable CW Pump Control

Site BMS• Chiller Cooling Call• Variable Secondary Pump Control• Chilled Water Reset (Valve Position)

Internet

Firewalli-Vū Pro Server PC

Web Browser

Chiller System Optimisation

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Presentation by:Ryan Hipps

Contents

• Existing installation• Original proposal• Burke Air proposal• Construction• Summary

Existing installation

Existing installation

Plantroom # 6

Existing installationPlantroom # 2

Existing installation

• Plantroom # 10

Existing Installation• Cooling Capacities:

– Chillers 1 & 2: 1440 kW• Feeding AHUs 1,2,3,4,5• Total AHUs cooling capacity: 1508 kW

– Chillers 3,4 & 5: 4623 kW• Feeding AHUs 7 to 14, 16 to 26 & FCUs 3 to 6 • Total AHUs cooling capacity: 4491 kW

– Chiller 6: 700 kW• Feeding AHU 15• Total AHU cooling capacity: 700 kW

– Total Chillers: 6723 kW• Total AHU cooling capacity: 6699 kW

• Issues:– Chillers 3,4,5 Condenser coils corroded, compressors

failures and end of life cycle.– Pipes corrosion– Pipes insulation: 25 mm– Chillers 1,2,3,4,5,6 refrigerant: R22– No balancing valves on AHUs– Pumps undersized– Recirculation

Existing Installation

Original Proposal

• Central plant room:– 4 water cooled chillers in series counter

flow– 3 cooling Towers in parallel– 2 CCW pumps– 2 PCWHP– 5 SCWHP – 5 separate loops– Total cooling capacity: 4x1775 kW=7100

kW

Original Proposal

Original Proposal

• Risks– Electrical mains to new plant room– Structural: existing roof and concrete slab– Vibration (Cinema)– Building works (DA approval, extra cost, less car bays, restriction

for future development)– Running of large pipework across car ramp

Original Proposal

BURKE AIR ProposalRoof Pipework layout

BURKE AIR Proposal

Central Plantroom # 6

• 4 Water cooled chillers in series counter flow

• 3 cooling towers in parallel• 2 CWP• 2 PCHWP• 4 SCHWP (Loop 1 to 4)• Cooling Capacity: 4x1775 kW

= 7100 kW

ConstructionTender / Design / Procurement

• December 2012 : Original Tender documents released• January 2013: Original bid based on original proposal• February to June 2013: BA design proposal with Westfield

Engineering and AECOM, 3D Concept design• June 2013: New tender documents• July 2013: 3D final design, Final Tender offer• August 2013: Signed contract / Procurement / Engineering /

Drafting

Construction

• September 2013: Start on site• October 2013: Roof pipework completed• October 2013: Installation of 4 chillers and 2 Cooling towers

associated pumps• October 2013: AHU plantrooms 70% completed• November 2013: Commissioning of Chillers 1.1 & 1.2 + CT 1

& 2• November 2013: AHU plantrooms 90% completed, chilled

water to loop 2 to 4.• December 2013: Commissioning of remaining chillers and

CT• January 2014: Commissioning of Loop #1 and associated

AHUs• January 2014: PC

Summary