INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING-AHMEDABAD COMPUTER AIDED DESIGN

1

INDEX

Sr. No

Title Page Date of

Start

Completion date

Initial of

faculty

Gr From To

1. Introduction regarding the Refrigeration and Air conditioning system.

2. To study Vapour compression and Compound compression.

3. To study the experiment on vapour absorption refrigeration cycle

4.

To study about steam jet refrigeration system, evaporators and refrigerants of the refrigeration systems.

5.

To study about psychometric and psychometric terms, Human Comfort and Load analysis of refrigeration systems.

6.

To study about air-conditioning systems, components and refrigeration and air – conditioning application.

INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING-AHMEDABAD COMPUTER AIDED DESIGN

2

* INSTRUCTIONS *

This laboratory manual is issued once only. This is your responsibility to preserve it in

good condition up to Term work submission & Oral examination.

Your writing should be neat and clean.

Get checked your manual at the end of the performance of each practical.

Practical & Tutorials that cannot be read or are not presented in a professional

engineering style will not receive credit (Higher Grades).

INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING-AHMEDABAD COMPUTER AIDED DESIGN

3

GUJARAT TECHNOLOGICALUNIVERSITY B.E. SEM VI (MECHANICAL)

Refrigeration and Air Conditioning 1 Refrigeration an introduction, heat load, development of refrigeration, aircraft

refrigeration, Bell-Coleman cycle, Bootstrap air refrigeration system, types of air cycles, advantages and disadvantages,

2 Vapour Compression system: Simple system on P-h diagram, analysis of the simple cycle, factors affecting the performance of the system, actual cycle considering different losses. Compound Compression System: Need, flash tank, Compound compression with flash and inter cooler, all evaporators working at the same temperature, evaporators with back pressure valves and with multiple expansion valves without flash inter cooling, analysis of two evaporators with flash inter cooler and individual and multiple expansion valve, estimation of power requirement and COP.

3 Absorption refrigeration system: Characteristics of refrigerant, selection of pair, practical water -NH3 cycle Li – Br system and its working.

4 Refrigeration system components: Compressors, condensers, expansion devises, evaporators its types construction and working, comparison and selection, refrigeration piping accessories and controls, thermal insulation properties and classification, thickness of insulation.

5 Steam jet refrigeration system: Basic concepts, system analysis, performance of steam jet refrigeration equipments, application, advantages and disadvantages.

6 Refrigerants: development, classification, designation of refrigerants, secondary refrigerants, future industrial refrigerants

7 Psychrometry and psychrometric terms: properties of air, Daltons law of partial pressure, humidity, temperature, enthalpy of moist air, temperature and humidity measuring instruments, plotting psychrometric chart, psychrometric processes such as sensible heating, cooling, heating and humidification cooling and dehumidification, chemical dehumidification, adiabatic saturation.

8 Human comfort: air temperature and human body, body thermoregulation, effective temperature, comfort chart and factors governing effective temperature.

9 Load analysis: Site survey, outdoor design conditions. Indoor design conditions, classification of loads, Flywheel effect of building material and its use in design,

INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING-AHMEDABAD COMPUTER AIDED DESIGN

4

Text Books: 1. Desai P.S, Modern Refrigeration and Air-conditioning Khanna Publishers, 2004 2. Manohar Prasad, "Refrigeration and Air Conditioning", Wiley Eastern Ltd., 1983 3. Arora. C.P., Refrigeration and Air Conditioning, Tata McGraw-Hill New Delhi, 1988 4. S C Arora & S Domkundwar, ‘Refrigeration and Air-Conditioning’ Dhanpat Rai Publication, 2009 Reference Books: 1. Roy.J Dossat, “Principles of Refrigeration”, Pearson Education 2009. 2. Jordon and Prister, “Refrigeration and Air Conditioning”, Prentice Hall of India PVT Ltd., New Delhi, 2009 3. Sapali S.N., "Refrigeration and Air Conditioning", PHI Learning Private Ltd, 2009. 4. W.F.Stocker and J.W.Jones, “Refrigeration and Air Conditioning", McGraw-Hill, 2009. 5. Ahmadul Ameen "Refrigeration and Air Conditioning", Prentice Hall of India Pvt. Ltd. 2010 6. S.S Thispee Refrigeration and air-conditioning , Jaico Publications, 2009 7. Ramesh Arora ,” Refrigeration and Air-conditioning”, Prentice Hall of India, 2010

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 thorough glass, total equivalent temperature difference, calculations of cooling load TETD due to sunlit and shaded walls using tables, air infiltration and load due to outside air, ventilation, heat gain from occupants, electric lights, product, electric motor and appliances, use of load estimation sheet.

10 Duct Design and air distribution: Function, classification economic factors influencing duct layout, duct design methods, velocity reduction, equal friction and static regain method, use of friction chart equivalent diameter, dynamic losses and its determination, Requirements of air distribution system, terms in air distribution, grills, outlets, application, location

11 Air conditioning system components: fans types laws, classification and selection, air cleaning devices classification, types, construction and working, humidifiers and dehumidifiers.

12 Refrigeration and air-conditioning application: food preservation, ice manufacturing, cold stores, air-conditioning of residential, commercial buildings.

INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING-AHMEDABAD COMPUTER AIDED DESIGN

5

List of Figures contained in Manual

Sr. No Figure Title Page No.

1

2

3

4

5

6

INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING-AHMEDABAD COMPUTER AIDED DESIGN

6

7

8

9

10

11 12

13

Tutorial: 1

INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING-AHMEDABAD COMPUTER AIDED DESIGN

7

AIM: Introduction regarding the Refrigeration and Air conditioning system. Laboratory work:

1. Define the following: (i) Refrigeration,

(ii) Refrigeration system (iii) Refrigerated system.

2. Enumerate different ways of producing refrigeration.

3. Enumerate important refrigeration applications. 4. State elements of refrigeration systems. 5. Enumerate systems of refrigeration. 6. Define the following:

(i) Actual C.O.P (ii) Theoretical C.O.P. and (iii) Relative C.O.P.

7. What is standard rating of a refrigeration machine?

8. Write short note on ice refrigeration.

Tutorial : 2 Vapour Compression and Compound Compression system

AIM: To study Vapour compression and Compound compression. Laboratory work:

Introduction

INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING-AHMEDABAD COMPUTER AIDED DESIGN

8

1. Describe a simple vapour compression cycle giving clearly its flow diagram.

2. State the functions of the following parts of a simple vapour compression system (i) Compressor (ii) Condenser (iii) Expansion Valve (iv) Evaporator

3. Factors effecting the performance of a simple vapour compression system.

4. Explain actual vapour compression cycle with different losses.

5. Explain the difference between compound system with flash cooling and flash

intercooling.

6. Explain compound compression with multiple expansion valves in series with flash chambers but no intercooling.

7. Explain compound compression with multiple expansion valves and flash intercooling system.

8. What are the advantages of compound compression with intercooler over single stage compressions.

PRACTICAL: 3

VAPOUR ABSORPTION REFRIGERATION SYSTEM AIM: To study the experiment on vapour absorption refrigeration cycle Laboratory Work:

INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING-AHMEDABAD COMPUTER AIDED DESIGN

9

1. Explain briefly with a neat diagram “Practical vapour absorption system’.

2. State the functions of the following components in an absorption system:

I. Absorber (iii) Analyser II. Rectifier (iv) Heat exchangers

3. State the advantages of vapour absorption refrigeration system over vapour compression refrigeration system.

4. Give the comparision between vapour absorption and vapour compression systems.

5. Draw a neat compact diagram of Lithium bromide water absorption refrigeration system and explain its working. List-out the major fields of application of this refrigeration system.

6. Derive an expression for C.O.P. of an ideal vapour absorption system in terms of TG, TE and TC. Where TG = Temperature at which heat (QG) is supplied to generator, TE = Temperature at which heat (QE) is absorbed in the evaporator, and TC = Temperature at which heat (QC) is discharged from condenser and absorber.

7. Properties of ideal refrigerant, absorbent and refrigerant, absorbent combination.

8. In an acqua-ammonia absorption refrigeration system of 9 tonnes refrigeration capacity the vapour leaving the generator temperatures are -20 C, 30 C, 40 C and 170 C respectively. At absorber exit the concentration of ammonia in solution is x = 0.35 and enthalpy h = 22 KJ/kg. At generator exit (weak solution) x = 0.1 and enthalpy h = 695 KJ/kg.

(i) Detremine the mass flow rate of ammonia in the evaporator.

INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING-AHMEDABAD COMPUTER AIDED DESIGN

10

(ii) Carry out overall mass conservation and mass conversation of ammonia in absorber to determine mass flow rates of weak and strong solution.

(iii) Determine the heat rejection in absorber and condenser, heat added in generator and C.O.P.

PRACTICAL: 4

AIM: To study about steam jet refrigeration system, evaporators and refrigerants of the

refrigeration systems.

INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING-AHMEDABAD COMPUTER AIDED DESIGN

11

THEORY: Laboratory work:

1. Describe the working of a steam jet refrigeration system with the help of a neat sketch.

2. What are the advantages and disadvantages of steam jet refrigeration system over other types of refrigeration systems.

3. Give the classification of evaporators.

4. Describe briefly the following:

(i) Pool boiling (ii) Flow or forced-convection boiling.

5. Explain with neat sketches the following evaporators:

(i) Flooded type evaporator (ii) Dry expansion evaporator

6. Name three refrigerants that are commonly used in commercial refrigerators. Discuss

their relative merits and demerits.

7. State the factors which are considered in selecting a refrigerant in the following systems and mention the same of refrigerant used in each system.

(i) Air-conditioning plant for picture house. (ii) Household refrigerator. (iii) Ice-producing plant.

8. Discuss why refrigerators are so selected that evaporator pressures and condenser

pressures are greater than atmospheric pressure?

PRACTICAL: 5

AIM: To study about psychometric and psychometric terms, Human Comfort and Load

analysis of refrigeration systems.

INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING-AHMEDABAD COMPUTER AIDED DESIGN

12

THEORY: Laboratory work:

1. State and explain the factors which affect comfort?

2. What is an ‘Effective temperature’? Explain briefly ‘Effective temperature chart’ and ‘Comfort chart’.

3. State and explain factors which govern optimum effective temperature.

4. Define the following terms: (i) Saturated air. (ii) Dry bulb temperature (iii) Dew point temperature (iv) Relative humidity (v) Specific humidity

5. State the ‘Dalton’s law of partial pressure.

6. Describe briefly the following processes:

(i) Sensible heating (ii) Cooling and dehumidification (iii) Heating and humidification (iv) Heating and dehumidification

7. List the variables which are involved in the estimation of load.

8. What points should be considered while making heat load calculations?

PRACTICAL: 6

SURFACE AND SOLID MODELING AIM: To study about air-conditioning systems, components and refrigeration and

air – conditioning application.

INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING-AHMEDABAD COMPUTER AIDED DESIGN

13

THEORY: Laboratory work:

1. Define and explain an ‘air-conditioning system with neat sketch. Name its basic elements.

2. Explain with neat sketch explain the main components of central air-conditioning system.

3. Explain the difference between summer air-conditioning and winter air conditioning.

4. Define room sensible heat factor. How room sensible heat factor line is drawn on the psychometric chart?

5. List the application of air-conditioning & Define room sensible heat factor and effective room sensible heat factor.

6. State the factor which should be taken into consideration while selecting a system of air-conditioning.

7. Describe briefly with a neat sketch a window type air-conditioner.

8. What is the function of a filter? How are filters classified? Explain briefly an automatic or self cleaning filter.

9. What purpose is served by a fan? How are fans classified?

10. Explain the construction and working of a domestic refrigerator, with the help of neat sketch.

11. Explain briefly the following with neat sketches: (i) All the year round air-conditioner. (ii) Year – round absorption air-conditioner.