JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

UNIT - I

Refrigeration cycles– analysis: Development of Vapor Compression Refrigeration Cycle from Reverse Carnot Cycle- conditions for high COP-deviations from ideal vapor compression cycle, Multipressure Systems, Cascade Systems-Analysis.

UNIT - II

Refrigerants: Classification of Refrigerants, Designation of Refrigerants, Desirable properties of refrigerants including solubility in water and lubricating oil, material compatibility, toxicity, flammability, leak detection, cost, environment and performance issues. Thermodynamic properties of refrigerants. Synthetic and natural refrigerants. Comparison between different refrigerants vis a vis applications. Special issues and practical implications. Montreal Protocol and the Kyoto Protocol

UNIT - III

Refrigerant Mixtures Introduction, The Need for replacement refrigerants, Binary mixtures- composition, temperature- composition, and enthalpy-concentration diagram, refrigerant mixtures, evaluation of thermodynamic properties, zeotropic and azeotropic mixtures, temperature glide. Charging procedure and Safety rules for the preparation of refrigerant mixtures. Advantages and limitations of refrigerant mixtures.

UNIT - IV

Assessment of Natural Refrigerants: Opportunities for the application of natural refrigerants, Use of hydrocarbons as working fluids in heat pumps and refrigeration equipment, Conversion of various HCFC-22 systems to hydrocarbon, Experimental assessment of HC-290 as a substitute to HCFC-22 in a window air conditioner

UNIT - V

Tools & Servicing Practices Tools: Different Types of Refrigeration Tools, Evacuation and Charging Unit , Recovery and Recycling Unit , Vacuum Pumps. Servicing Practices: Contaminants-Moisture, on-condensables, Servicing RAC systems-Evacuation, Purging, Leak detection,

REFERENCE BOOKS:

• 1. Natural Refrigerants Sustainable Ozone- and Climate-Friendly Alternatives to HCFCs, Proklima International, 2008
• 2. Refrigeration & Air Conditioning Technology, By William C. Whitman, William M. Johnson, John A.
• 3. Refrigeration and Air Conditioning by C P Arora, McGraw-Hill edition
• 4. Alternatives to HCFCs in the Refrigeration and Air conditioning Sector - Practical Guidelines and Case Studies for Equipment Conversion, Retrofit and Replacement, UNEP
• 5. R &AC -Manohar Prasad