Syllabus Heating, Ventilation, Air Conditioning and Refrigeration - (402041) Credits Examination Scheme Theory : 3 In-Semester : 30 Marks Practical : 1 End-Semester : 70 Marks Oral : 25 Marks Unit 1 Gas Cycle Refrigeration and Refrigerants Gas Cycle Refrigeration : Application to air-craft refrigeration, Simple system, Bootstrap, Regenerative, reduced ambient system, Concept of Dry Air Rated Temperature (DART). Refrigerants : Introduction, Definition and requirement, Classification of refrigerants, Designation of refrigerants, Desirable properties of Refrigerants-Thermodynamic, Chemical and Physical. Properties of ideal refrigerant. Environmental issues like ODP, GWP & LCCP. Selection of environment friendly refrigerants, Alternative refrigerants, Secondary refrigerants, Anti-freeze solutions, Zeotropes and Azeotropes, Refrigerant recovery, reclaims, recycle and recharge. (Chapters - 1, 2) Unit 2 Multi Pressure Systems Systems Multistage or compound system : Need of multi staging, Two stage compression with flash gas removal, flash intercooler and complete multistage compression system. Multi evaporator system : single compressor-individual expansion valve, single compressor-multiple expansion valve, individual compressor-multiple expansion valve, individual compressor with compound compression and flash inter cooling. (Limited to two evaporators). Ammonia-CO2 cascade cycle. (Chapter - 3) Unit 3 Practical aspects of Vapor Compression and Advanced Refrigeration Systems Major components of refrigeration cycle : Types of compressors, Characteristics of reciprocating and centrifugal compressors, Types of evaporators, Types of condensers and Types of expansion valves. Safety Controls : LP/HP cut-off, Low temperature control, Frost control, Motor overload control, Oil pressure failure control. Capacity control of different compressors. Advanced Refrigeration System : Transcritical cycle and their types, Simple ejector refrigeration system (analysis and numerical). (Chapters - 4, 5) Unit 4 Applied Psychrometry Psychrometric Chart, Psychrometric processes using BPF, ADP, SHF, RSHF, GSHF, ESHF, ERSHF and adiabatic mixing of two air streams. Heat load estimation: - Air conditioning, heating & cooling load calculations. Envelop Load estimation : Concept of sol-air temperature, Time lag & Decrement method and ETD or CLTD methods. Thermal Comfort : Basic parameters, Thermodynamics of human body, Thermal comfort and Comfort charts, Factors affecting thermal comforts. Indoor Air Quality (IAQ) : Indoor air contaminants, Basic strategies to improve indoor air quality. Outdoor Design Conditions : Outdoor air requirements for occupants, Use of outdoor weather data in design, Outdoor weather characteristics and their influence. (Chapter - 6) Unit 5 Ventilation, Infiltration & Air Distribution Systems (Ducts) Ventilation and infiltration : Natural ventilation, Mechanical ventilation. Duct Design : Definition of duct and types of ducts, Economic factors influencing duct layout, Materials for ducts and its specification, Flow through duct, Pressure in ducts, Friction loss in ducts, Friction chart for circular ducts, Equivalent diameter of a circular duct for rectangular sections, Methods of duct designs. (Numerical treatment on duct design). Air Distribution System : Factors considered in air distribution system, (simple numerical). Types of air distribution devices. Fan coil unit, Fan laws, Types of fans used air conditioning applications, Types of supply air outlets, Selection and location of outlets, Filters, Diffusers, Grillers, and Dampers. (Chapter - 7) Unit 6 Advanced Air Conditioning Systems Advanced AC Systems : Working of summer, winter and all year round AC systems, all air system, all water system, air water system, variable refrigerant flow and variable air volume systems, unitary and central air conditioning. Desiccant-Based Air Conditioning Systems : Introduction, Sorbents & Desiccants, Dehumidification, Liquid spray tower, Solid packed tower, Rotary desiccant dehumidifiers, Hybrid cycles, Solid desiccant Air-Conditioning (Theoretical treatment). Evaporative Cooling Air Conditioning Systems, Thermal storage Air Conditioning systems, Clean room Air Conditioning systems, Radiant cooling. (No numerical), Heat pumps and its different circuits. (Chapter - 8)
