District Cooling Summit Qatar 2010, IQPC
The Musheireb Project Master Planning & Design Concept For District Cooling Davar Abi-Zadeh , Arup Fellow, Arup, London
Contents • The Project • Global Issues • Why is district cooling important? • Design to reduce energy demand • Heat dissipation & water sources • Case studies and crafty ideas
Urban Layers The Musheireb Project - Heart of Doha Qatar Massing Building Height
35 HA Regeneration Scheme 760,000m2 GFA Mixed Use
THE PROJECT Vision and Overall Objectives To create a sophisticated city district with vitality for the people of Doha ….. • ‘A rising homeland that confidently embraces modernisation and proudly observes tradition’ • ‘A culture of quality firmly rooted in the infrastructure of our country’ • 'A modern state in the context of Arab culture, tradition and religious beliefs’ • 'A meeting not a melting of cultures’ • 'An environment of freedom, creativity, innovation, communication, meeting and interaction' His Highness The Emir and Her Highness Sheikha Mozah
…. through sustainable urban regeneration to revitalise Inner Doha.
The Project • 35 Ha Site • Mixed Use Development • Very High Quality • City Centre Location • Close to Amiri Diwan • Multi Discipline Project • UK/Doha/Hong Kong Input • Key Client – Doha Land (Qatar Foundation) • Arup Fee circa £6.0m • 12 month Programme from July 2008.
Urban Layer Basement Strategy
Urban Layers Basement Strategy Basement
Urban Layers Basement Strategy Primary Service Corridor
Urban Layers Basement Strategy Basement with Superblock Structures
Urban Layers Vehicular Movement
Urban Layers Land Use Ground Floor
Urban Layers Land Use Typical Upper Floors
A Sustainable City: a better lifestyle
Main Square Daytime
Boutique Shopping Along the Street
Wadi Experience Section
Why is District Cooling Important for the Project? • Cooling accounts for up to 70% of peak electricity demands in summer months.
Residential
Commercial
• Typical electricity use in buildings
District Cooling for the Musheireb • What does the customer want? → Low cost cooling → Reliable supply
• What does the utility provider want? → Profit → Secure income stream → Predictable energy supply cost
• What does the world want? → Reduce carbon emissions → Avoid fuel poverty
Design issues for Master Planning What can the designer do?
• Design to reduce energy demand • Design to supply energy efficiently • Maximise use of renewable energy
Reduce Demand Business-as-Usual & Low Carbon Cooling Loads
Building Type
BAU Design Cooling Load Densities (W/m²)
Low Carbon Cooling Load Densities (W/m²)
Residential
120
50?
Commercial
150
80?
Retail
220
100?
Community, Mosque
180
90?
Cultural, School
180
90?
Hotel
200
100?
Administrative
150
80?
Diurnal Cooling Load Distribution - Mixed Use Development
120000 C o o lin g L o a d (k W )
100000 80000 60000 40000
Thermal storage for peak lopping
20000 0 0
5
10
15
20
25
Time of Day (hrs) Residential
Commercial
Retail
Community
Cultural
Diwan Admin
National Archive
Mosque
School
Average Load Profile
Hotel
Efficiency of Supplying Chilled Water – Scale Effects District Cooling, Building Cooling and Room Cooling
Renewable Energy • • • • •
Concentrated Solar Thermal Solar Photovoltaics Wind Power Biomass Energy Waste to Energy
Efficiency of Supplying Chilled Water - Technology Efficiency of Alternative Cooling Technologies
Implications for Developers Paradigm shift – developer becomes utility provider • Changes in the role of State and Municipality • Finance and fuel • Changes in the technology of supply • New business models - apportionment of risks - need for regulation - delivery mechanisms Will it work?
Role of Designer in Delivering Low Carbon District Cooling
Reduce cooling demand Central generation chilled water Use renewable energy wherever possible
The Museireb DC: Low carbon cost effective district cooling through design and innovation
The Musheireb Project Master Plan
Location of Central Cooling Plants & Infrastructure Overview
CP1 CP2
District Cooling System Components 22 Superblocks
Potable Water (Back-up)
Potable Water (Back-up)
Wadi Sewer Water gravity feed Cooling Towers
Cooling Towers
Storage
Storage ETS
ETS
ETS
CHW Flow Chillers
Chillers
CHW Return
Pump Pit
Water Storage
Return to Wadi Sewer
Water Treatment
Cooling tower Make Up Blowdown
Waste Streams
Blowdown
Reject Sump
Conventional Chillers Cooling Towers
Alternative Integrate with a desalination plant
Back to Basics: Vapour Compression Cycle Efficiency • 1°C improvement in both Evap and Cond approach:
Cooling Tower
• Chiller efficiency improves by 4.3 -4.8%. Pressure
• District Cooling : 35,500TR Plant would give a saving of 1,000kW in power.
Condenser Cooling Water Temperature
LCWT LChWT
Evaporator
Cooling Effect
Power Input
Enthalpy
Heat Dissipation: System Selection
• Condenser water: re-circulation • Evaporation • Bleed • ≈ Evaporation rate / (Cycle - 1)
• Drift loss • Water losses (Eva.+Bleed+Drift) • Water consumption for top up
Water Source – Fresh Water (BaU) Load ~ 125 MW Re-circulation ~ 23,000 m3/hr Make-up Water~ 300 m3/hr Total Water ~ 1.3 Mm3/yr
Enough Water: 20,000 people
Water Source – Wadi water, Waste Water, Sewer Water with Cooling Towers Load ~ 125 MW Re-circulation ~ 23,000 m3/hr Make-up Water~ 250 m3/hr Total Water ~ 1.5 Mm3/yr
Water Source – Cooling Tower & Sea Water Make-up Load ~ 125 MW Re-circulation ~ 23,700 m3/hr Make-up Water~ 820 m3/hr Total Water ~ 3.5 Mm3/yr
Water Source – Sea Water (Once through) Load = 125 MW Re-circulation ~ 53,000 m3/hr Make-up Water = 53,000 m3/hr Total Water = 230 Mm3/yr
Summary of Heat Dissipation Options Energy & carbon foot print Cooling Towers, Wadi Water
Cooling Towers, Sea Water
Once Through Cooling, Sea Water
GWh/yr
GWh/yr
GWh/yr
GWh/yr
Cooling towers & pumps
17.1
17.1
18.3
Water supply & treatment
0.0
2.9
0.6
36.2
17.1
20.0
18.8
36.2
4.9
-
-
-
Cooling system total energy
22.0
20.0
18.8
36.2
Chillers & CHW pumps
92.6
92.6
96.6
96.6
114.6
112.6
115.5
132.8
51,100
50,100
51,400
59,100
System
Annual electricity demand:
Cooling System Embodied energy: fresh water
Total Carbon Footprint, Tonnes/yr
BaU Potable Water
-
Cooling system energy consumption
50
Chiller Eff. Loss Embodied Energy WS,Water Treat CT & Pumps
40 GWh/Y
30 20 10 0
BaU
CT & WTP
MCT
Options
OT
Total energy consumption (cooling tower and chillers) Comparison of energy usage for different cooling strategies 140%
Energy Consumption (%)
120%
100%
80% 86%
Chillers and CHW Distribution Energy Cooling Water Energy
60%
82%
82%
86%
40%
20%
32% 20%
18%
17%
BaU Cooling Towers Fresh Water
Cooling Towers Sewer Water
Cooling Towers Sea Water
0%
Once Through Sea Water System
Heat Dissipation Systems OPEX & CAPEX
Vapour Compression Chiller DC Plant 125MW (35,500TR)
BaU Cooling Towers fresh water
Cooling Towers wadi water
Cooling Towers sea water
Once through sea water system
CAPEX (Million US$)
61
66
92
90
OPEX (Million US$)
6.8
5.5
5.4
5.9
Based on: Electricity cost: 0.04 $/KWH and Water cost: 1.49 $/m3
Cooling Towers Design Issues • Sensitive locations • Visual impact: screening • Noise from cooling plant • Vapour plumes
Courtesy of Qatar Cool
• Solution • Screening • Noise attenuation • Design to reduce plumes
75MW
Pluming Mitigation
0.020
0.020
0.018
0.018
0.016
0.016
Moisture Content [kg/kg]
Moisture Content [kg/kg]
• On Line Control
0.014 0.012 0.010 0.008 0.006
Saturation Line
0.004
PLUME
Tangent to Sat. Line
0.002
5
10
15
20
Ambient Dry Bulb Temperature [°C]
0.012
Readjusted tower outlet
0.010 0.008
Saturation Line
0.006 0.004
Ambient condition
0.002
NO PLUME
0.000
0.000 0
Theoretical tower outlet
0.014
25
0
5
10
15
20
Ambient Dry Bulb Temperature [°C]
25
The Musheireb Chilled Water Distribution
Basement and service Tunnel, Master Plan stage
Building Block
Building Block
Phasing Overview
• Thank You Questions
Conclusions • The cooling demand consumes large amount of energy, e.g. 70% of total electricity. • 80% of the district cooling energy is used to chill the water (refrigeration plant). • The demand must be reduced through sustainable and good engineering. • Use renewable and waste energy if it is available. • Energy consumption for cooling system with sea water is the least ss than the three options considered.
Implications for Developers Paradigm shift – developer becomes utility provider • Changes in the role of State and Municipality • Finance and fuel • Changes in the technology of supply • New business models - apportionment of risks - need for regulation - delivery mechanisms Will it work?
Doha - History
Access Interrupting Infrastructure and MEP
Global Issues
Water Scarcity
Global Warming
Fossil Fuel Depletion
Urbanisation
