Absorption Chillers

1. CB503
VENTILATION & AIR CONDITIONING 3
TOPIC 3 : DISTRICT COOLING SYSTEM
NAZRIZAM BINTI AB. WAHAB
pnnazz@gmail.com
017-612 5556 PSA/ CB503/ PNNAZZ

2. PSA/ CB503/ PNNAZZ

3. 1. Palm District Cooling
2. Qatar Cool Overview
3. District Cooling System Installation
and Overview in Baltimore (Q3)
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4. GENERAL DESCRIPTIONS/ DEFINITIONS OF
DISTRICT COOLING SYSTEM
• District Cooling Systems (DCS) is a system which
distribute chilled water or other media, usually
provided from a dedicated cooling plant, to multiple
buildings for air conditioning or other uses.
OR
• District Cooling System (DCS) can be defined as
centralized production and distribution of chilled water
from a cooling plant to residential, commercial and
industrial facilities trough a network of underground
pipes.
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5. OBJECTIVE OF DCS
To centralized production
of chilled water by using district
cooling plant. The generated
chilled water will then be
channeled to various
building blocks thru pre-
insulated seamless
underground pipes.
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6. WHAT IS DISTRICT COOLING?
1. DC means the centralized production and distribution of
cooling energy. Chilled water is delivered via an
underground insulated pipeline to office, industrial and
residential buildings to cool the indoor air of the buildings
within a district. Specially designed units in each building
then use this water to lower the temperature of air
passing through the building's ACS.
1. The output of one cooling plant is enough to meet the
cooling-energy demand of dozens of buildings. DC can
be run on electricity or natural gas, and can use either
regular water or seawater. Along with electricity and
water, DC constitute a new form of energy service.
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7. 3. DC is measured in refrigeration ton (RT) which is
equivalent to 12000 BTU's per hour. RT is the unit
measure for the amount of heat removed. RT is defined
as the heat absorbed by one ton of ice (2000 pounds)
causing it to melt completely by the end of one day (24
hours).
3. DCS can replace any type of ACS, but primarily compete
with air-cooled reciprocating chiller systems serving large
buildings which consume large amounts of electricity.
This ACS is subject to a difficult operating
environment, including extreme heat, saline humidity and
windborne sand. Over time, performance, efficiency and
reliability suffer, leading to significant maintenance costs
and ultimately to equipment replacement.
WHAT IS DISTRICT COOLING?
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8. HISTORY OF DISTRICT COOLING
1. The oldest district heating system was created in the early 14th
century in Chaudes-Aigues Cantal - a village in France. This system
distributed warm water through wooden pipes and it is still in use
today.
2. The first commercial district heating system was created by Birdsill
Holly in Lockport, New York in 1877. Holly used the boiler as the
central heat source and built a loop consisting of steam
pipes, radiators, and even condensate return lines. His system
started off with 14 customers. Only 3 years later, it served several
factories as well as residential customers and had extended to a 3-
mile loop.
3. District cooling also has its roots in the 19th century. It was
introduced as a scheme to distribute clean, cool air to houses
through underground pipes. The first known district cooling system
began operations at Denver's Colorado Automatic Refrigerator
Company in late 1889. In the 1930's, large district cooling systems
were created for Rockefeller Centre in New York City and for the
U.S. Capital Buildings in Washington, D.C. PSA/ CB503/ PNNAZZ

9. HOW DISTRICT COOLING WORKS?
1. Chilled water is produced in a central plant and distributed via a
system of pipes that can run underground, on the surface or over
rooftops.
2. Inside the buildings, these transmission pipes are normally
connected to a conventional air handling unit or fan coil that allows
the water to chill the air passing through.
3. This means multiple chiller units placed locally are no longer
required.
4. Once the required thermal energy has been extracted from the cold
water, this water is returned to the central plant to be re-chilled and
re-circulated through the closed-loop piping system.
5. This cooling system is more flexible and also operates with higher
efficiency under all load conditions than traditional chillers.
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10. ADVANTAGES OF DISTRICT COOLING
SYSTEM
1. Improve efficiency of energy
2. Protect environment
3. Save space
4. Improve urban view
5. Re-use the heat from exhaust system
6. Prevent disaster
7. Reduce manpower for operation
and maintenance
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11. WHY IS DISTRICT COOLING ENVIRONMENTAL
FRIENDLY?
District cooling helps the
environment by increasing
energy efficiency and
reducing environmental
emissions including air
pollution, the greenhouse
gas (GHG) carbon dioxide
(CO2) and ozone-destroying
refrigerants. District cooling
can reduce annual CO2
emissions by about 1 ton for
every ton of district cooling
refrigeration demand served.
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12. DISTRICT COOLING SYSTEM
VS
CONVENTIONAL REFRIGERANT SYSTEM
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17. TYPE OF REFRIGERANTS FOR DCP
• Brine, and propylene-glycol are the famous
examples used in DCP.
• Known as “secondary cooling media”, it is not
really a refrigerant.
• This type of heat transfer media is used for
delivering cool temperature from air conditioner
evaporator, to cooling coils.
• These are used in very large air conditioning
system, or “district cooling”.
• The reasons are, to keep the maintenance
cost, safety risk, and compressor breakdown, low.
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18. PSA/ CB503/ PNNAZZ

19. DCS IN MALAYSIA
Since 1997, chilled water and
electricity have been supplied to
airport facilities from the Chiller
Plant. Shinryo Corp. contracted
with 35,000 RT designed chilled
water capacity. Current installed
capacity consists of 12 nos.
2500 RT double effect steam
absorption chillers. Owner:
Gas District Cooling (M)
Sdn Bhd Date of
Completion: Mar 1997
1. Kuala Lumpur International Airport
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20. DCS IN MALAYSIA
Putrajaya area was developed for
the transfer of the capital city
Kuala Lumpur in Malaysia. Plant
started to supply chilled water to
the government office complex in
1999. Plant capacity was 27,500 RT
which included 2 nos. of 1250 RT
ECC, integrated chilled water
storage system, 5nos. of 2500 RT
SAC and 5 nos. of 1500 RT
DFC. Owner: Gas District Cooling
(M)
Sdn Bhd Date of
Completion: Dec 2000
2. Putrajaya Precinct 1 DCS Plant
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21. • The District Cooling System in Bangsar supplies
chilled water to a district that comprises :
– The Cygal Hotel and the Cygal Towers A &B
– The Atlas Towers A to F
– Menara Telekom and Wisma Telekom
– Tenaga Head Quarters (TNB)
• Objective :
– To take advantage of the lower electricity tariff
during the night, the Cristopia Thermal Energy
Storage System (STL) is used with the purpose
of storing thermal energy during the night for use
during the day.
DCS IN MALAYSIA
3. Bangsar District Cooling Plant
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22. • Characteristics :
– The plant consists of 5 centrifugal chillers (3500 kW each)
working in conjunction with 5 cylindrical STL steel tanks of
380 m³ (3.80 m diameter, 35 m long).
– Two conventional water chillers are used for the base load.
– Each brine chiller operates with one STL and one heat
exchanger to provide brine at 3.3 C at the primary side of
the heat exchanger.
– Each loop (5) operates independently of the others.
– The chillers and the STL's can be operated singularly and
separately or in any combination to cater for the
demand, and the decision for their operating status during
the day is based on the objective of minimizing the use of
the chillers and depleting the energy stored.
DCS IN MALAYSIA
Bangsar District Cooling Plant
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23. • Technical Data :
– Daily Cooling Energy Consumption : 450,000 kWh
– Maximum Cooling Demand : 40,000 kW
– Cooling Energy Stored : 110,000 kWh
– STL Storage Volume : 1,900 m³
– Number of Tanks : 5 nos
• Technical Advantages :
– Smaller chiller capacity
– Smaller heat rejection plant
– Reduced maintenance
– Efficient and reliable system
– Increase of the plant life time
– Flexible system available for efficient energy management
DCS IN MALAYSIA
Bangsar District Cooling Plant
PSA/ CB503/ PNNAZZ

24. • Financial Advantages :
– Saving on operating costs, maintenance, demand
charge and off peak consumption
– Lower initial investment
• Projects Credits
– Customer : Bangsar Energy Systems SDN BHD
(subsidiary of TNEC)
– Consultant: KJ Engineering
– Installing Company: KJ Engineering
DCS IN MALAYSIA
Bangsar District Cooling Plant
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25. DCS IN MALAYSIA
4. UKM District Cooling Plant
– Completed and operational in
1998
– District cooling plant serving 10
faculties within the University.
– Energy conservation award
winning plant for Retrofitting
Category
– Chiller plant capacity of 3,700
RT (13.0 MWr)
– Thermal storage capacity of
11,300 RTH
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26. 5. Malaysia Institute
of Nuclear Technology
– Completed and
operational in 2001
– Chiller plant capacity
of 1,500 RT (5.3
MWr)
– Thermal storage
capacity of 6,000
RTH
DCS IN MALAYSIA
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27. 6. Serdang Hospital
– Completed and
operational in 2002
– 600 bed hospital
– Chiller plant
capacity of 2,800 RT
(9.8 MWr)
– Thermal storage
capacity of 6,000
RTH
DCS IN MALAYSIA
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28. 7. KLCC Cogeneration Plant
Upgrading
– Completed and
operational in 2005
– Upgrading of additional
12,000 RT (42.2 MW) to
cater additional load and
energy optimization
solution
– Thermal storage capacity
of 45,000 RTH
DCS IN MALAYSIA
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29. 8. Putrajaya Precint 1 (P1)
– Completed and operational in 2008
– Retrofit existing plant by additional 12,000 RT (42.2
MW) to a more reliable system
– Thermal storage capacity of 48,000 RTH
DCS IN MALAYSIA
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30. 9. MBSA (Shah Alam
Municiple)
– Completed and operational
in 2006
– District cooling plant
serving Shah Alam including
the Selangor Council
building
– Upgrading of additional
2,400 RT (8.4 MW) to
convert existing plant to
District Cooling Plant
– Thermal storage capacity of
45,000 RTH
DCS IN MALAYSIA
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31. 10. 1 Borneo
– Completed and
operational in 2008
– Chiller plant capacity
of 5,700 RT (20.0
MWr)
– Thermal storage
capacity of 16,800
RTH
DCS IN MALAYSIA
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32. 11. Institute Jantung Negara (IJN)
– Completed end 2008
– Chiller plant capacity of 1,200 RT (4.22 MWr)
– Thermal storage capacity of 7,100 RTH
DCS IN MALAYSIA
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33. DCS COMPONENTS
• A typical DCS comprises the following components:
1. Central Chiller Plant
– generate chilled water for cooling purposes
2. Distribution Network
–distribute chilled water to buildings
3. User Station
–interface with buildings' own air-conditioning
circuits.
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34. 1. Central Chiller Plant
– Chilled water is typically generated at the central
chiller plant by compressor driven chillers, absorption
chillers or other sources like ambient cooling or “free
cooling” from deep lakes, rivers, aquifers or oceans.
– Groups of large and energy-efficient water-cooled
chillers are usually installed in a central chiller plant
to take advantage of the economy of scale and the
cooling demand diversity between different buildings
within a district.
– Sea water condensers or fresh water cooling towers
can be utilized to reject waste heat from the central
chillers. PSA/ CB503/ PNNAZZ

35. 2. Distribution Network
– District chilled water is distributed from the cooling
source(s) to the user stations through supply pipes
and is returned after extracting heat from the
building’s secondary chilled water systems.
– Pumps distribute the chilled water by creating a
pressure differential between the supply and return
lines.
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36. 3. User Station
– The interface between the district cooling system and the
building cooling system is commonly referred to as user station.
– The user station usually comprise of air handling units, heat
exchanger and chilled water piping in the building.
– A user station is required in each user's building to connect the
DCS distributed chilled water pipe to the building.
– Inside the user station, devices called heat exchangers are
installed to transfer heat between the chilled water supply of
DCS and the air-conditioning system of the user building.
– The user station could be designed for direct or indirect
connection to the district cooling distribution system.
– With direct connection, the district cooling water is distributed
within the building directly to terminal equipment such as air
handling and fan coil units, induction units, etc.
– An indirect connection utilizes one or multiple heat exchangers
in between the district system and the building system.
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37. A. Mechanical
1. Centrifugal Chillers
2. Condenser water Pumps
3. Chilled Water Primary Pumps
4. Chilled Water Secondary Pumps
5. Cooling Towers
6. Make up water pumps for Cooling Towers
7. Chemical Dosing system for Cooling Towers
8. Chemical Dosing system for chilled water network
9. R.O Plant for blow down water re-claim
10. Water Storage Tank for Cooling Towers / Fire Pumps
11. Blow Down Storage Tank
12. Thermal Storage Tanks
DISTRICT COOLING PLANT EQUIPMENT
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38. B. Electrical
1. 11 kV Switchgear (3.3 kV if applicable)
2. 11kV Capacitor banks
3. 11 kV / 400 Ton Transformers (11 kV / 3.3 kV
Transformers if applicable)
4. H.V Cables and containment systems
5. UPS / Battery Charger for 11 kV vacuum circuit
breakers
6. L.V Switchgear
7. Motor control centres
8. L.V capacitor banks
DISTRICT COOLING PLANT EQUIPMENT
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39. C. Control Systems
1. Building Management System (BMS) or CMS (Plant
Control Management System).
2. PLC System for data control
3. System Data server
4. Operator work stations
5. Energy work station
DISTRICT COOLING PLANT EQUIPMENT
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40. Cooling Tower Cooling Tower Fan & Motor
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41. Typical Thermal Storage Tank Thermal Storage Tank
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42. Air Cooled Chiller Water Cooled Chiller Module
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43. Fan Coil Unit AHU Unit
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44. Motor Control Center 11kV Switchgear
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45. CONTROL SYSTEMS
Control System SCADA System Projector Screen
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46. HEAT EXCHANGER (HE)
• HE are used to transfer heat from one medium to
another, such as from steam to hot water, or from
water at a higher temperature to water at a lower
temperature.
• Two basic types of HE :
– Shell and tube type
– Plate type
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47. 1. SHELL-AND-TUBE TYPE (STT)
– The STT of HE consists of a bundle of tubes in the
shell.
– Primary medium is either steam or water, which
flows in the shell.
– Secondary medium is always water, which flows
through the tubes.
– The tubes are partitioned to allow single or multiple
passes to increase the temperature and the heat
transfer.
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HEAT EXCHANGER (HE)

48. PSA/ CB503/ PNNAZZ
2. PLATE TYPE (PT)
– PT HE composed of multiple, thin, slightly separated plates that have
very large surface areas and fluid flow passages for heat transfer.
– This stacked-plate arrangement can be more effective, in a given
space, than the STT.
– Advances in gasket and brazing technology have made the plate-type
heat exchanger increasingly practical.
– Large HE of this type are called plate-and-frame; when used in open
loops, these heat exchangers are normally of the gasket type to allow
periodic disassembly, cleaning, and inspection.
– There are many types of permanently bonded plate heat
exchangers, such as dip-brazed and vacuum-brazed plate
varieties, and they are often specified for closed-loop applications
such as refrigeration.
– PT HE also differ in the types of plates that are used, and in the
configurations of those plates.
– Some plates may be stamped with "chevron" or other patterns, where
HEAT EXCHANGER (HE)

49. PSA/ CB503/ PNNAZZ
SHELL-AND-TUBE TYPE (STT)

51. TASBIH KIFARAH
(Maha Suci Engkau Ya Allah dan Segala Puji
BagiMu, aku bersaksi bahawa tiada Tuhan
melainkan Engkau, aku memohon keampunan dan
taubat daripada Engkau)