Chilled Water System Introduction, Myanmar

႔ Chapter-1 Introduction

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Chapter-1 Introduction to Chilled Water Systems

၁.၁ What is heat?

(heat) ႔ (temperature) ႔ ႔ (transfer) (form of energy) (temperature) တ ႔ (thermal activity)

(form of energy) (quantity) ႔ (intensity) (heat energy) (form of energy) ႔

(thermal activity) (molecules) တ (thermal activity) ႔ (velocity) ႔ (thermal activity) ႔

first law (heat energy) ႔ first law “law of conservation of energy” HVAC

second law (heat energy) (temperature) ႔ (transfer)

Chillers and Chilled Water Systems ႔

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၁.၁.၁ (Heat)

(thermometer) intensity of heat (quantity of heat) ႔ (quantity of heat) ႔ (quantity of heat)

၁-၁ 1 Callorie (4.187J) ၁-၂ 1 Btu

၁.၂ Unit of Refrigeration

Refrigeration capacity Inch-Pound (I-P) HVAC refrigeration

(၂၄) (1 ton) 32°F (144 Btu) (144 Btu/lb) (၂၀၀၀) one refrigeration ton (1RT) 12,000 Btu/hr

Table 1-1

(gram) ႔ 1°C 1 Calorie [cal] ( )

(lb) ႔ 1°F 1 British Thermal Unit (BTU)

1 ton of refrigeration (RT) = 200 Btu/min = 3.517 kJ/s = 3.517 kW


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( / ) (amount of heat) Kilocalorie [kcal] 1 kg 1°C 1 kcal Joule [J] 1 g 1°C 4.187 J Kilojoule[kJ] 1 kg 1°C 4.187 kJ British Thermal Unit [BTU] 1 lb 1°F 1 Btu

၁.၃ Sensible Heat Sensible heat Equation:

= Rate of sensible heat added or removed from substance (Btu/hr) = Weight rate flow of substance (lb/hr) = Specific heat of substance at constant pressure (Btu/lb °F) = = temperature change or substance (°F)

Air conditioning process sensible heat equation Air con process (temperature change) ႔

- chiller chilled water flow rate (၅၀၀) 55°F (chilled water) 43°F chiller cooling capacity Btu/hr ton of refrigeration(RT) kW ႔

Chiller cooling capacity (amount of heat removed from chilled

႔ gpm lb/hr ႔

= 250,000 lb/hr

(1 GPM) lb/hr ႔ 500 lb/hr

=-3,000,000 Btu/hr

(heat) ႔ ( ) ( ) Btu/hr refrigeration ႔ 1 RT (Refrigeration Ton) 12,000 Btu/hr = 3.517 kW

Cooling capacity

Chilled water circuit ႔ chiller water sensible heat (transfer) [ ] latent heat (transfer)


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၁.၄ Air Conditioning System

၁-၃ Air conditioning system

၁-၃( ) Classification of HVAC systems

Air conditioning system project ႔ system (perform

႔ ႔ (construction manager) ႔ (value-engineered options)

system


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(၁) (Temperature)

(၂) (Humidity)

(၃) (Air motion)

(၄) ႔ ႔ (Air purity or quality)

(၅) (Air changes per hour)

(၆) Duct pipe (Air and/or water velocity requirements)

(၇) (Local climate)

(၈) (Space pressure requirements)

(၉) Load calculation analysis capacity

(၁၀)

(၁၁) (Spatial requirement)

(၁၂) (Security concerns)

(၁၃) (First cost)

(၁၄) (Operating cost, including energy and power costs)

(၁၅) (Maintenance cost)

(၁၆) System (Reliability)

(၁၇) (Flexibility)

(၁၈) ႔ ႔ system (Life-cycle analysis)

(၁၉) (Sustainability of design)

(၂၀) (Acoustics and vibration)

(၂၁) (Mold and mildew prevention) ႔

Air conditioning system decentralized cooling and heating system central cooling and heating system Decentralized system


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၁-၄ Multiple unit systems using single-zone unitary HVAC equipment

၁-၅ Packaged Terminal Air Conditioner

၁.၅ Decentralized Cooling and Heating System

႔ decentralized system ႔

၁.၅.၁ System Characteristics Decentralized system HVAC unit

HVAC unit refrigeration cycle heating source air ventilation (components) fans filters heating source cooling coil refrigerant compressor(s) control condenser ႔

Equipment (manufacture) ႔ configuration decentralized system HVAC equipment

(၁) Window air conditioners (၆) Water cooled packaged unit

(၂) Multiple-unit systems (၇) Self-contained (floor-by-floor) systems

(၃) Outside package systems (၈) Water-cooled heat pump systems

(၄) Air-cooled heat pump systems (၉) Residential and light commercial split systems

(၅) Air-cooled packaged unit (၁၀) Through-the-wall room HVAC units


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၁-၆ Packaged DX rooftop air conditioner

၁-၇ ource heat pump

၁-၈ DX unit ၁-၉ Packaged rooftop air conditioner

၁.၅.၂ Decentralized System (Advantages) (၁) Heating cooling

(၂) Certified rating performance data

(၃) (quality control) (reliability)

(၄)

(၅)

(၆)


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(၇)

(၈) System

(၉) Mechanical electrical

(၁၀) (first cost)

(၁၁) equipment

(၁၂) (tenant) air con service

(၁၃) Decentralized system air-side ႔ water-side economizer

၁.၅.၃ Decentralized System (Disadvantages) (၁) Air flow cooling coil condenser

(၂) centralized system diversity factor enquipment

(၃) (temperature) (humidity)

(၄) equipment equipment

(၅) Central system

(၆) Outside air economizer

(၇) ႔ (air distribution)

(၈) Equipment

(၉) Equipment

(၁၀) air filtration ႔

(၁၁) On/off ႔ step control discharge temperature

(၁၂) Air-conditioning unit condensate drain

(၁၃) Equipment ႔

၁.၆ Central Cooling and Heating System Central cooling plant chiller water (generate)

႔ distribution ႔ HVAC application ၂၅% central cooling plant system Equipment ႔


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၁.၆.၁ System Characteristics

equipment configuration Equipment Primary equipment chiller boiler ႔ capacity configuration

႔ oil) ႔

႔ ႔ ႔ air conditioning heating process

၁-၁၀ Central cooling and heating system (oprating) (maintain) (first cost) ႔ (owner) consulant ႔

(၁) ႔ campus (Campus environments with

distribution to several buildings.) (၂) (High-rise facilities)

(၃) (Large office buildings)

(၄) (Large public assembly facilities, entertainment complexes, stadiums, arenas, and convention and exhibition centers-)

(၅) Urban centers (e.g., city centers/districts)

(၆) (Shopping malls) (၇) (Large condominiums, hotels, and apartment complexes)

(၈) (Educational facilities)

(၉) (Hospitals and other health care facilities)

Chilled-water production system HFC ႔ HCFC refrigerant (safety requirement) ASHRAE Standard 15


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(၁၀) (Industrial facilities -pharmaceutical, manufacturing)

(၁၁) (Large museums and similar institutions)

(၁၂) ႔ (Locations where waste heat is readily available - generation or industrial processes))

chilled water plant ( ) Chiller configuration

( ) Pump (efficient pumps)

( ) Valve

(ဃ) (good piping scheme with ample valving) ႔

System control (access)

၁.၆.၂ Central System (Advantages) (၁) Primary cooling and heating

(၂) equipment

(၃) Equipment servicing

(၄) (energy-efficient design strategies) (energy recovery) thermal storage (energy management) ႔

(၅) plant

(၆) equipment (spare part) Part-load capability efficiency equipment

(၇) Standby capability back-up power supply

(၈) Load profile equipment equipment

(၉) Central plant distribution

(၁၀) Load diversity total installed capacity

(၁၁) Equipment (vibration) (noice) ႔

၁.၆.၃ S Disadvantages) (၁) Equipment


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(၂) Centralized system

(၃) Centralized equipment ႔

(၄)

(၅)

(၆) Equipment ႔ (accees)

(၇) Heating plant chimney emission permit monitoring treatment

(၈) Equipment manufacturer equipment

(၉) Central system control logic

(၁၀) (first cost)

(၁၁)

(၁၂) (safety)

(၁၃) Distribution pipe

၁.၆.၄ Site of Central Plant Central plant (၁) refrigerant ႔ (discharge)

(၂) Equipment , lifting facility

(၃) (maintenance

(၄) (acoustical impact)

(၅) (expansion)

၁.၇ Design Considerations

၁.၇.၁ Cooling and Heating Loads individual lo cooling load heating load simultaneous peak ႔ simultaneous load ( ) cooling load ႔ heating load (၄) Design load peak load ႔ “equipment diversity factor” - 5 95% diversity (university) diversity factor ၄၅% ႔ Central plant peak load diversity factor ႔ diversity factor


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၁.၇.၂ (Noise) (Vibration)

႔ ႔ S S

႔ S —

၁.၇.၃ Space Considerations ) (architects) (owners)

(space planners) M&E mechanical equipment

mechanical system building configuration ႔ rules of thumb ႔ design concept (space requirement) (building floor area) Mechanical and Electrical (M&E) system ၆ ၉ ႔

Central system 1 kW refrigeration (plant room) 0.07 0.09 (0.07 to 0.09 m2 per kilowatt of refrigeration) Chiller pump cooling tower equipment 1.2 m ႔ equipment Chiller evaporator condenser ႔ tube ႔

location) ႔ a ႔ (dis- ႔ overhead crane ႔ S S (local codes)


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၁-၁၁ Chilled water distribution network

၁.၇.၄ L

Ce • Equipment (operating weight) (structural costs)

• Equipment (vibratioin) (noise) ႔

• Central plant switchgear motor control center transformer cable

• Cooling tower makeup water tank

•

• cooling and heating service

• central plant

• (road way) (parking)

operating environment for e S ventilation rate) 2.5 L/s per m2


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• (fuel oil) propane gas coal ႔

• Electrical transformer

• Cooling tower ႔ ႔ ႔ ႔ ႔

ASHRAE ၂၀၀၈

(၁) emergency electrical loads)

(၂)

(၃) fuel sources)

(၄) ႔ ႔ ႔ ႔

(၅) control)

၁-၁၂ Central cooling system

၁.၈ Chilled Water System (၁) Constant flow systems ( ) Constant flow using 3-way control valves ( ) Constant flow using 2-way control valves and central by-pass (၂) Primary secondary flow system ( ) Primary constant /Secondary variable flow design ( ) Primary constant /Secondary variable flow design (with tertiary pumping) (၃) Variable Primary Flow chilled water systems (VPF) ( ) VPF with dedicated pumps ( ) VPF with headered pumps


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၁.၉ Overview of Chiller Plant Room chiller water plant

႔ chilled water system Chilled water system chiller pump cooling tower AHU/FCU system heat exchanger pump Chilled water system water cooled chiller ႔ air cooled chiller Water cooled chiller system ႔ plant water-cooled plant (water cooled system) Air cooled chiller system ႔ plant air-cooled plant (air cooled system)

Water cooled chiller circuit (၄) air cooled chiller circuit (၃) Air cooled ႔ water cooled chiller refrigerat circuit chiller

၁-၁၃ Water Cooled Chiller Air Cooled Chiller DX Packaged

Thermal energy moves from left to right through five loops of heat transfer

၁-၁၄ (1) (2) (3) (4) (5)

(၁) Indoor air loop

(၂) Chilled water loop

(၃) Refrigerant loop

(၄) Condenser water loop

(၅) Cooling tower outdoor air loop


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၁-၁၅ Heat transfer loop

Tabel 1-2 water cooled chilled water system and air cooled chilled water system Water Cooled Chilled Water System Air Cooled Chilled Water System

( ) ႔ air distribution system ႔ air distribution system

( ) Chilled ႔ chilled water distribution system

႔ chilled water distribution system

( ) Condenser circuit

(ဃ) refrigerant circuit Chiller refrigerant circuit

၁-၁၆ Chiller condenser water pipe chilled water pipe

၁.၁၀ Circuit (Naming of Circuit) Circuit (supply) (return) ႔ (entering)

(leaving) Supply return Chilled water circuit ႔ load side reference Chiller (leaving chilled water) chilled water supply (supply to building) chiller ႔ (entering chilled water) chilled water return (return from building) Chilled water loop/circuit


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chiller supply side AHU/FCU demand side(load side)

Condenser water circuit cooling tower chiller chiller reference Chiller ႔ (entering condenser water) condenser water supply (supply to chiller) chiller (leaving condenser water) condenser water return (return from chiller) Air side circuit serving area reference AHU/FCU supply air (supply air to serving area) air return air (return air from serving area)

၁.၁၁ Chilled Water Distribution System ႔ Chilled Water Circuit/Loop Chilled water distribution system ႔ chilled water circuit/loop chilled water pump

chiller Air Handling Unit(AHU)/Fan Coil Unit(FCU) ႔ Chilled water pump chilled water return chiller Chilled water pump chilled water supply ႔ chilled water pump chilled water chiller ႔ ႔ ႔ chiller ႔ ႔ chiller evaporator (heat exchage)

Chilled water circuit/loop Air-Conditioning, Heating and Refrigeration Institute (AHRI) [ ARI ] (standard) chilled water supply temperature . chilled water return temperature . (standard chilled water flow rate) 1 RT (၂.၄) (2.4 S chiller (standard chilled water flow rate) - 500RT( ၅၀၀) chiller (standard chilled water flow rate) .

(heat) (tempe (temperature) ႔ ႔ chilled water circuit 12.2°C chilled water return (temperature) refrigerant circuit ႔ chiller evaporator refrigerant 12.2°C chilled water return 6.7°C chilled water supply chiller Chilled water circuit closed circuit (closed loop) Closed circuit chilled water (atmosphere) ႔

၁.၁၂ Condenser Water Loop ႔ Condenser Water Circuit Condenser water loop ႔ condenser water circuit condenser water pump chiller

cooling tower ႔ Condenser water pump condenser water supply chiller Condenser water pump condenser water return ႔ condenser water pump condenser water chiller ႔ ႔ ႔ chiller ႔ ႔ chiller condenser (heat exchage)

Condenser water circuit/loop AHRI (Air-Conditioning, Heating and Refrigeration Institute) (standard) condenser water supply temperature


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(outdoor air) web bulb temperature (၁.၅) ႔ (၂.၀) Condenser water supply temperature web bulb temperature Standard condenser water return temperature condense (standard condenser water flow rate) 1 RT (၃.၀) . S (electic driven) chiller standard condenser water flow rate - 500RT ( ၅၀၀) chiller (standard condenser water flow rate ) .

(heat) (temperature) ႔ ႔ condenser water circuit (heat) chiller refrigerant circuit condenser water supply temperature ႔ condenser water supply refrigerant circuit Condenser water supply refrigerant circuit condenser water return chiller Condenser water circuit/loop opened circuit/loop Opened circuit/loop condenser water (atmospheric) ႔

၁-၁၇ AHU chilled water pipe duct

၁.၁၃ Air Distribution System (Circuit/Loop) Air distribution system (circuit/loop) Air Handling Unit(AHU) blower cold air (supply

air) serving area ႔ ႔ servicing area warm air (return air) servicing area (temperature) 22°C supply air (temperature) 13°C Return air temperature 24°C (outdoor air)

(air flow rate) chilled water flow rate condenser water flow rate ႔ AHU Constant Air Volume(CAV) system Serving area cooling load (air flow rate) AHU Variable-Air-Volume (VAV) system

-End-


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Contents ၁.၁ What is heat? .............................................................................................................. 1

၁.၁.၁ (Heat) ................................................................................................ 2

၁.၂ Unit of Refrigeration ..................................................................................................... 2

၁.၃ Sensible Heat .............................................................................................................. 3

၁.၄ Air Conditioning System ................................................................... 4

၁.၅ Decentralized Cooling and Heating System ..................................................................... 6

၁.၅.၁ System Characteristics .................................................................................................................. 6

၁.၅.၂ Decentralized System (Advantages) ................................................................. 7

၁.၅.၃ Decentralized System (Disadvantages) ............................................................ 8

၁.၆ Central Cooling and Heating System .............................................................................. 8

၁.၆.၁ System Characteristics .................................................................................................................. 9

၁.၆.၂ Central System (Advantages) .......................................................................... 10

၁.၆.၃ Central System (Disadvantages) .................................................................... 10

၁.၆.၄ Site of Central Plant ..................................................................................................................... 11

၁.၇ Design Considerations ................................................................................................. 11

၁.၇.၁ Cooling and Heating Loads ........................................................................................................... 11

၁.၇.၂ (Noise) (Vibration) .............................................................................................. 12

၁.၇.၃ (Space Considerations ) ....................................................................................... 12

၁.၇.၄ Location of Central Plant and Equipment ........................................................................................ 13

၁.၈ Chilled Water System ............................................................................... 14

၁.၉ Overview of Chiller Plant Room..................................................................................... 15

၁.၁၀ Circuit (Naming of Circuit) ................................................................... 16

၁.၁၁ Chilled Water Distribution System ႔ Chilled Water Circuit/Loop ............................ 17

၁.၁၂ Condenser Water Loop ႔ Condenser Water Circuit ............................................. 17

၁.၁၃ Air Distribution System (Circuit/Loop) .......................................................................... 18


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၁.၁ What is heat? 1 ၁.၁.၁ (Heat) 2 ၁.၂ Unit of Refrigeration 2 ၁.၃ Sensible Heat 3 ၁.၄ Air Conditioning System 4 ၁.၅ Decentralized Cooling and Heating System 6 ၁.၅.၁ System Characteristics 6 ၁.၅.၂ Decentralized System (Advantages) 7 ၁.၅.၃ Decentralized System (Disadvantages) 8 ၁.၆ Central Cooling and Heating System 8 ၁.၆.၁ System Characteristics 9 ၁.၆.၂ Central System (Advantages) 10 ၁.၆.၃ Central System (Disadvantages) 10 ၁.၆.၄ Site of Central Plant 11 ၁.၇ Design Considerations 11 ၁.၇.၁ Cooling and Heating Loads 11 ၁.၇.၂ (Noise) (Vibration) 12 ၁.၇.၃ (Space Considerations ) 12 ၁.၇.၄ Location of Central Plant and Equipment 13 ၁.၈ Chilled Water System 14 ၁.၉ Overview of Chiller Plant Room 15 ၁.၁၀ Circuit (Naming of Circuit) 16 ၁.၁၁ Chilled Water Distribution System ႔ Chilled Water Circuit/Loop 16 ၁.၁၂ Condenser Water Loop ႔ Condenser Water Circuit 17 ၁.၁၃ Air Distribution System (Circuit/Loop) 18

Chilled Water System Introduction, Myanmar

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