REFRIGERATION AND AIR-CONDITIONING

GUJARAT TECHNOLOGICAL UNIVERSITY

MECHANICAL ENGINEERING (19)

SUBJECT NAME:- REFRIGERATION AND AIR-CONDITIONING

SUBJECT CODE:- 2161908

B.E. 6th SEMESTER

1. Introduction:- Brief history and need of refrigeration and air conditioning, methods of producing cooling, ton of refrigeration, coefficient of performance, types and application of refrigeration  and air condensing system.
2. Refrigerants:- classification, nomenclature, desirable properties, secondary refrigerants, future industrial refrigerants.
3. Air refrigeration:- Reversed Carnot cycle and its limitation, Bell-Coleman cycle, aircraft refrigeration, working and analysis of simple; Bootstrap; Reduced ambient and Regenerative air refrigeration systems.
4. Vapor Compression system- Simple system on P-h and T-s diagrams, analysis of the simple cycle, factors affecting the performance of the cycle, actual cycle                                                                                                                                          Compound Compression System:- Compound Compression with intercooler, flash gas removal and flash intercooler, multiple evaporators with back pressure valves and with multiple expansion valves without flash intercooling, analysis of two evaporators with flash intercooler and individual expansion valve and multiple expansion valve, Cascade refrigeration system.
5. Absorption refrigeration system:- Practical H20-NH3 Cycle, LiBr-H2O system and its working, h-x diagram and simple calculation of various process like adiabatic mixing and mixing with heat transfer, throttling, Electrolux refrigeration system.
6. Refrigeration system components:- Types, Construction, working, comparison and selection of compressors, condensers, expansion devices and evaporator; refrigeration piping accessories, evacuation and charging of refrigerant, properties and classification of thermal insulation.
7. Psychrometry:- Dalton’s law of partial pressure, Properties of moist air, temperature and humidity measuring instruments, psychometric chart, psychrometric processes such as sensible heating and cooling, heating and humidification cooling and dehumidification, chemical dehumidification, adiabatic saturation.
8. Human comfort:- Selection of inside design conditions, thermal comfort, heat balance equation for a human being, factors affecting thermal comfort, effective temperature, comfort chart and factors governing effective temperature, selection of outside design conditions
9. Load analysis:-site survey, outdoor and indoor design conditions. classification of loads, flywheel effect of building material and its use in design, effect of wall construction on cooling load, instantaneous heat gain (IHG) and instantaneous cooling load (ICL) heat  transmission through sunlit and shaded glass using tables, method of reduction of solar heat gain through glass, calculation of cooling load TETD due sunlit and shaded roof and walls using tables, ventilation and air infiltration, load due to outside air , heat gain from occupants; electric lights; product; electric motor and appliances, load calculations for automobiles, use of load estimation sheet. Introduction of CLTD method
10. Duct design and air distribution:- Function; classification and economic factor influencing duct layout, equal friction , velocity reduction and static regain methods of duct design, use of  friction chart, dynamic losses and its determination,  Requirements of air distribution system, air distribution, grills, outlets, application, location.
11. Air-Conditioning systems:- Classification, system components, all air; all water ; and air-water systems, room air conditioners,  packaged air conditioning plant, central air conditioning system, split air conditioning systems.