It is the Short Description of the Vapor Absorption Cooling/ Refrigeration System.Contains Intro, Comparison of VCCS 7 VACS, Diagram, Advantages & Disadvantages & Applications of the System

1. VAPOR ABSORPTION
COOLING SYSTEM
Muhammad Ali Haider
ME-09 B
SMME ,NUST

2. REFRIGERATION/COOLING
• Process of lowering the Temperature of the enclosed space by removing heat from it.
• A fluid called refrigerant is filled and flows through closed pipes , this process
completes by the phase change of the refrigerant.
• Common Refrigerants used for Refrigeration are ; R23 , R404A , R407A , Ammonia .
• Working Principle Of Refrigeration is the transfer of heat from low temperature
medium to High Temperature with the Addition of work to the system ; Clacius Law.
• Types of Refrigeration System
• Vapor Absorption cooling System(VACS)
• Vapor Compression cooling system(VCCS)

3. VAPOR ABSORPTION COOLING SYSTEM
(VCCS)
• Introduction:
An absorption refrigerator is a refrigerator that uses a heat source to provide the energy needed
to drive the cooling system. A vapor absorption system makes use of a substance, called
absorbent to absorb large volumes of the vapor of a refrigerant even when cold and reduce it to a
liquid, and subsequently give off its vapors when heated.
• Types:
 Single pressure absorption system
o Uses lithium bromide salt as absorbent & water as refrigerant.
 Water spray absorption system
 Simple absorption system
o Uses ammonia as refrigerant & water as absorbent.

4. VAPOR ABSORPTION COOLING SYSTEM
(VCCS)
• Principle
• Components
 Evaporator
 Vapor Generator
 Condenser
 Expansion Valve
Evaporato
r
Absorber
Pump
Condenser
GeneratorExpansion
Valve
1
23
4
Q’ in
W’ in
Q’ out
Qout
Q in

5. COMPARISON OF VCCS & VACS
• Both cycles circulate refrigerant inside the chiller to transfer heat from one fluid to the
other.
• VACS uses pump instead of compressor b/w evaporator & condenser to increase pressure
of Absorbent bcz it is in liquid phase at that stage.
• VACS uses refrigerants that have no bad effect on the Environment i.e Ammonia &
Lithium Bromide. But VCCS uses halocarbon i.e (HCFC-123, HCFC-22, HFC-134a).
• Performance of VACS is not sensitive to the load variation.
• VACS has low COP but it has low operation cost because it works on the waste heat of
powerplants.

6. • Advantages
• Less Noise
• Can be used to above 10000 ton Capacity.
• Corrosion Problem is less.
• Low Maintenance cost.
• Disadvantages
• Low COP
• Only Ammonia can be used as refrigerant.
• Bulky in Size

7. APPLICATIONS & BENEFITS
• It is mostly used in Cold Storage and icemaking Plants.
• It is used in Oil Refineries, Chemical Plants & Recreational Vehicles.
• VACS uses thermal energy to give instant chilled water for Co-generation Plant.
• Absorption chillers uses very little electricity compared to an electric motor driven
compression cycle chiller.
• It can be used to Air-Condition buildings by using waste heat of Cogeneration
Plant;Trigeneration.
• Absorption chillers do not use CFCs or HCFCs - the compounds known for causing Ozone
depletion.