Chapter10 Refrigeration

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Chapter10 Refrigeration Cycle
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10-1 Vapor-Compression Cycle
Coefficient of Performance
10-1-1 The Reversed Carnot Cycle
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• Disadvantages
• Process 2-3 is difficult to be Fulfill in
  compressor
• Process 4-1 will do harm to turbine

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10-1-2 The Ideal Vapor-Compression Refrigeration
Cycle
Equipments
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evaporator
compressor
condenser
Capillary tube
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10-1-3 The COP of Vapor-Compression Cycle
h-s diagram
h
s
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Usually p1, p2 are available
From p1, get h1, s1 h1 h1 s1
s1 From p2 , s1, get h2 From p2 , get h2
h3 h2 h4 h3
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p-h diagram
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p
3
2
4
1
h
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10-2 Refrigerant
High enthalpy of vaporization Not too low
evaporator pressure Not too high condenser
pressure Nontoxic Noncorrosive Chemically
stable Low cost
Good refrigerant

• Ammonia
• CFC(chlorofluorocarbons)
• water

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10-3 Heat Pump
An equipment Absorbing heat from environment for
heating purpose
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Heat pump for heating
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Heat pump for refrigeration
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10-4 Innovative Vapor-compression Refrigeration
Systems
10-4-1 Regenerative Vapor Compression cycle
Equipments
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T-s Diagram
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10-4-2 Cascade Refrigeration Systems
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T-s Diagram
T0
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10-4-3 Multistage Compression Refrigeration
Systems
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10-4-4 Multipurpose Refrigeration Systems with a
Single Compressor
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10-4-5 Liquefaction of Gas
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10-5 Gas Refrigeration cycle
10-4-1 Equipments
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10-4-2 COP of Gas Refrigeration Cycle
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• To decrease compression ratio can increase COP
• To To decrease compression ratio will decrease
  power ratio

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10-4-3 Regenerative Gas Refrigeration Cycle
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regenerator
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1
4
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turbine
compressor
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10-6 Absorption Refrigeration System
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Refrigerant Ammonia Transport medium
Water
Refrigerant Water Transport medium
Lithium bromide
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10-6 Adsorption Refrigeration
condenser
Active carbon
evaporator
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Cooling tower
Vacuum tube
Active carbon
Cooling Tube
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The End of This Chapter Thank You