ME-312T
REFRIGERATION AND AIRCONDITIONING (2+0)
BSME 2016-20
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COURSE CONTENTS
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RECOMMENDED TEXTS
1- R S Khurmi, J K Gupta, Textbook of Refrigeration & Air conditioning,
S Chand & Co, 1987
2- W F Stoecker, J W Jones, Refrigeration and Air Conditioning, 2nd Ed. New York: McGraw-Hill,
1982
3-C P Arora, Refrigeration & Air conditioning, 3rd ed McGraw-Hill, 2010
4-G F Hundy, A R Trott, T C Welch, Refrigeration & Air conditioning, 4th ed,
ButterworthHeinemann, 2008
5- P N Ananthanarayanan, Basic Refrigeration & Air conditioning, 3rd ed, McGraw-Hill, 2005
6-ASHRAE Handbook
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REFRIGERATION
• The process of achieving and maintaining the temperature below atmospheric
temperature is called refrigeration.
• Refrigeration involves, transfer of heat from low temperature reservoir to high
temperature reservoir.
• The transfer of heat from a low-temperature medium to a high-temperature one
requires special devices called refrigerators.
• Refrigerators, like heat engines, are cyclic devices. The working fluid used in the
refrigeration cycle is called a refrigerant
• Consider following two cases,
• Cooling of hot water with the help of fan (is it a refrigeration process?)
• Cooling of hot water with large quantity of Ice (is it a refrigeration process?)
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AIR CONDITIONING
The process by which air is
• Cooled
• Heated
• Filtered
• Humidified/dehumidified
• Circulated/recirculated
in order to achieve desired room conditions.
So Air conditioning means , controlling the temperature,
humidity, quantity and quality of air in order to achieve
desired conditions.
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nd
2 LAW of THERMODYNAMICS
• Clausius Statement
It is impossible to construct a
device that operates in a cycle
and produces
no effect other than the transfer of
heat from a lower-temperature
body to a higher-temperature
body
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Room Air Conditioner
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Domestic Refrigerator
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Unit of Refrigerating Capacity
The standard unit of refrigeration is ton refrigeration or simply ton
denoted by the symbol TR. It is equivalent to the production of cold
at the rate at which heat is to be removed from one US tonne of
water at 32°F to freeze it to ice at 32°F in one day or 24 hours.
Ton
Tonne
Metric
UK
(1016 kg)
US (2000 lbs = 907.2 kg)
1000 kg
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Unit of Refrigerating Capacity
The standard unit of refrigeration is ton refrigeration or simply ton
denoted by the symbol TR. It is equivalent to the production of cold
at the rate at which heat is to be removed from one US tonne of
water at 32°F to freeze it to ice at 32°F in one day or 24 hours. Thus
where the latent heat of fusion of ice has been taken as 144 Btu/lb.
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Unit of Refrigerating Capacity
• In many countries, the standard MKS unit of kcal/hr is used.
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