LOK NAYAK JAIPRAKASH INSTITUTE OF

TECHNOLOGY, CHAPRA

COURSE FILE

OF

REFRIGERATION & AIR CONDITIONING

(ME1x20)

Faculty Name:

PIYUSH KUMAR PANDEY

ASSISTANT PROFESSOR,

DEPARTMENT OF MECHANICAL ENGINEERING

CONTENTS

1. Cover Page & Content

2. Vision of the Department

3. Mission of the Department

4. PEO’s and PO’s

5. Course objectives & course outcomes (CO’s)

6. Mapping of CO’s with PO’s

7. Course Syllabus and GATE Syllabus

8. Time table

9. Student list

10. Course Handout

11. Lecture Plan

12. Assignment sheets

13. Sessional question papers

14. Old End Sem Question Papers

15. Question Bank

16. Results

17. Results analysis

18. Teaching Evaluation

Vision of Mechanical Engineering Department

The Mechanical Engineering department visions to be known globally in the field of technical

education and to overcome the issues of industry and society.

Mission of Mechanical Engineering Department

1. To deliver outcome based education to undergraduate students

2. To establish an environment for students where they can build professional and personal

integrity to pursue long productive career.

3. To maintaining state of the art research facilities to provide collaborative environment

that stimulates faculty, staff and students with opportunities to create, analyze, apply and

disseminate knowledge.

4. To equip students with good academic, corporate and entrepreneurship skills as well as

create global awareness in them required by engineering profession

Program Educational Objectives

1. To prepare the students for successful career in industries, entrepreneurship or in higher

studies. (Preparation)

2. To inculcate engineering attitude to analyze, design and solve real life engineering

problems. (Core knowledge)

3. To promote the students for continuous learning, with strong professionals, ethical and

moral values. (Learning Environment)

Program Specific Outcomes

The graduates of Bachelor of Engineering in Mechanical Engineering Program will be able to:

1. Design and develop mechanical as well as inter disciplinary components by experimental,

numerical and analytical techniques

2. Apply their knowledge from field of mathematics and science fields to solve problems

related to mechanical engineering.

Program Outcomes

1. Engineering knowledge: Apply the knowledge of mathematics, science, engineering

fundamentals, and an engineering specialization to the solution of complex engineering

problems.

2. Problem analysis: Identify, formulate, review research literature, and analyze complex

engineering problems reaching substantiated conclusions using first principles of

mathematics, natural sciences, and engineering sciences.

3. Design/development of solutions: Design solutions for complex engineering problems

and design system components or processes that meet the specified needs with

appropriate consideration for the public health and safety, and the cultural, societal, and

environmental considerations.

4. Conduct investigations of complex problems: Use research-based knowledge and

research methods including design of experiments, analysis and interpretation of data,

and synthesis of the information to provide valid conclusions.

5. Modern tool usage: Create, select, and apply appropriate techniques, resources, and

modern engineering and IT tools including prediction and modeling to complex

engineering activities with an understanding of the limitations.

6. The engineer and society: Apply reasoning informed by the contextual knowledge to

assess societal, health, safety, legal and cultural issues and the consequent responsibilities

relevant to the professional engineering practice.

7. Environment and sustainability: Understand the impact of the professional engineering

solutions in societal and environmental contexts, and demonstrate the knowledge of, and

need for sustainable development.

8. Ethics: Apply ethical principles and commit to professional ethics and responsibilities

and norms of the engineering practice.

9. Individual and team work: Function effectively as an individual, and as a member or

leader in diverse teams, and in multidisciplinary settings.

10. Communication: Communicate effectively on complex engineering activities with the

engineering community and with society at large, such as, being able to comprehend and

write effective reports and design documentation, make effective presentations, and give

and receive clear instructions.

11. Project management and finance: Demonstrate knowledge and understanding of the

engineering and management principles and apply these to one’s own work, as a member

and leader in a team, to manage projects and in multidisciplinary environments.

12. Life-long learning: Recognize the need for, and have the preparation and ability to

engage in independent and life-long learning in the broadest context of technological

change.

Course Description

For specific applications, efficiencies of both living and non-living beings depend to a great extent on the

physical environment. The nature keeps conditions in the physical environment in the dynamic state ranging

from one extreme to the other. Refrigeration and air-conditioning is the subject which deals with the

techniques to control the environments of the living and non-living subjects and thus provide them comforts

to enable them to perform better and have longer lives.

Course Objectives

On completion of this course, students should be able to

1. Understand the basic principles of refrigeration and air conditioning

2. Analyze air refrigeration systems, vapor compression refrigeration systems, vapour

absorption refrigeration systems, and steam jet refrigeration systems

3. Study the psychometric properties of air and utilize the principles of psychometric in the

design of air conditioning equipment

4. Finally apply this knowledge for the design of refrigeration equipment and air conditioning

equipment

Course Outcomes

ME1x20.1: Analyze and design refrigeration machine, heat pump and also solve complex

problems on vapour compression and absorption refrigeration system.

ME1x20.2: Select the components and refrigerants for specific applications and its impact on

environment.

ME1x20.3: Analyze special refrigeration system like cascade, vortex, thermoelectric and steam

jet refrigeration system.

ME1x20.4: Understand and explain the various terminologies involved in psychrometric process.

ME1x20.5: Estimate cooling load calculations for various air-conditioning systems.

CO-PO MAPPING

Sr. No. Course Outcome PO

1. ME1x20.1. Analyse and design refrigeration machine, heat

pump and also solve complex problems on vapour

compression and absorption refrigeration system.

PO1, PO2, PO3, PO4,

2. ME1x20.2. Select the components and refrigerants for specific

applications and its impact on environment.

PO1, PO3, PO6, PO7, PO12

3. ME1x20.3. Analyze special refrigeration system like cascade,

vortex, thermoelectric and steam jet refrigeration system. PO1, PO2, PO3, PO4

4. ME1x20.4. Understand and explain the various terminologies

involved in psychrometric process. PO1, PO3, PO4, PO7

5. ME1x20.5. Estimate cooling load calculations for various air-

conditioning systems. PO1, PO2, PO3, PO4

CO PO1 PO2 PO3 PO4 PO5 PO6 PO7 PO8 PO9 PO10 PO11 PO12

ME1x20.1 3 3 3 3 - - - - - - - -

ME1x20.2 3 - 3 - - 3 3 - - - - 2

ME1x20.3 3 2 3 2 - - - - - - - -

ME1x20.4 3 - 3 1 - - 3 - - - - -

ME1x20.5 3 3 3 2 - - - - - - - -

CO PSO1 PSO2

ME1x16.1 3 3

ME1x16.2 3 3

ME1x16.3 3 3

ME1x16.4 3 3

ME1x16.5 3 3

B. Tech. VII Semester (Mechanical)

ME 1x20 REFRIGERATION & AIR CONDITIONING

L-T-P: 3-0-3 Credit: 5

1. Air refrigeration system: Refrigeration machine, heat pump, coefficient of performance, ideal

refrigeration cycle, Bell – Coleman, refrigeration cycle, open and closed systems, application of air-

refrigeration in air-crafts. Lecture: 6

2. Various compression systems: Simple vapour compression refrigeration cycle, merits and

Refrigerants demerits of this system over air refrigeration system, factors affecting the performance of

a vapour compression refrigeration system, sub cooling and superheating of vapour, wet and dry

compression, multistage vapour compression system, intercooler, flash chamber, accumulator and heat

exchanger. Lecture: 8

3. Vapour absorption system: Simple and modified vapour absorption refrigeration system, Electrolux

refrigerator, COP of heat operated refrigeration system. Lecture: 5

4. Special refrigeration system: absorption, cascade, vortex, thermoelectric and steam jet refrigeration

system. Lecture: 4

5. Refrigerants: classification and nomenclature of refrigerants, primary and secondary refrigerants,

properties of some common refrigerants, physical, chemical and thermodynamics properties, selection

of refrigerants, leakage of refrigerants and methods of detection. Lecture: 3

6. Equipment: Elementary discussion of refrigerating equipment, ice plant and cold storage.

Lecture :1

7. Psychrometry: Properties of air vapour mixture, wet bulb, dew point & dry bulb temperatures,

humidity, specific humidity, humidity ratio, degree of saturation, relative humidity, total heat

psychrometric relation, psychometric charts and its uses, psychometric processes evaporative cooling.

Lecture: 5

8. Air conditioning: General principle and requirement for comfort and air conditioning,

thermodynamics of human body, estimation of heating and cooling loads, capacity of cooling coils,

humidification and dehumidification unit and conditioner, central air conditioner, year around air

condition, humidity and temperature control, industrial application of air conditioning system.

Lecture: 10

Books:

1. Refrigeration and air conditioning by C P Arora

2. Refrigeration and air conditioning by Manohar Prasad

3. Refrigeration and air conditioning by Jordon & Priester

GATE SYLLABUS

REFRIGERATION AND AIR-CONDITIONING

Refrigeration and air-conditioning: Vapour and gas refrigeration and heat pump cycles; properties of moist

air, psychrometric chart, basic psychrometric processes.

SUBJECT- Refrigeraion and air conditioning

BRANCH- MECHANICAL (VII SEMESTER)

NAME OF FACULTY- PIYUSH KUMAR PANDEY

S. No Name Roll No.

1 ABHISHEK PATEL 17-M-02

2 SUDISH KUMAR 17-M-03

3 MD. SAZID ANSARI 17-M-04

4 ADITYA SUMAN 17-M-06

5 RAHUL PRASAD 17-M-07

6 MD. ATIQULLAH KHAN 17-M-08

7 PAPPU PRASAD 17-M-10

8 PAWAN KUMAR 17-M-11

9 JITENDRA KUMAR 17-M-12

10 MD. TARIQUE ANWAR 17-M-14

11 YASIR 17-M-15

12 ABHISHEK KR TIWARI 17-M-16

13 MUNNA KR GUPTA 17-M-17

14 PANKAJ KUMAR 17-M-18

15 SHIV SHANKAR 17-M-19

16 ANUJ KUMAR 17-M-20

17 ARPIT KUMAR 17-M-21

18 MD. IRSHAD AHMAD 17-M-22

19 ASHISH KUMAR 17-M-23

20 MD. REZAUR RAHMAN 17-M-24

21 SUMIT KR SHARMA 17-M-25

22 MD. RAHBER REYAZ 17-M-26

23 SHIVCHARAN KUMAR 17-M-27

24 GITESH KR SHARMA 17-M-28

25 AVINASH CHAUDHARY 17-M-29

26 DINESH KR CHAUDHARY 17-M-30

27 PRASHANT KR CHAUDHARY 17-M-31

28 CHANDAN KUMAR 17-M-32

29 VIMAL KUMAR 17-M-34

30 ANSHUMAN KUMAR 17-M-36

31 MUKESH KR SINGH 17-M-37

32 AMRENDRA KR SHARMA 17-M-38 33 RAUSHAN KUMAR 17-M-39

34 MANISH KUMAR 17-M-40

35 DEEPAK KUMAR 17-M-41

36 RAJ KUMAR 17-M-43

37 SURAJ KUMAR 17-M-44

38 AMIT KUMAR RAJ 17-M-45

39 KARTIKESHWAR SAH 17-M-46

40 AYUSH KUMAR 17-M-48

41 VIKKI KUMAR 17-M-49

42 VINAY RANJAN 17-M-50

43 SUMIT KUMAR 17-M-51

44 SIDHARTH KUMAR 17-M-52

45 PAPPU KUMAR 17-M-53

46 ASMITA ARYA 17-M-54

48 AJEET KR PRASAD 17-M-57

49 AMIT RANJAN 17-M-58

50 ARYAN RAJ 17-M-59

51 MD. SHAHADAT 17-M-60

52 SAURABH KR RAUSHAN 17-M-61

53 SHRINARAYAN PRASAD 17-M-62

54 FAIZ AHMAD 17-M-63

55 AMIT KUMAR 17-M-64

56 MITHILESH KUMAR 17-M-65

57 SATISH KUMAR 17-M-66

58 AMAN KUMAR 17-M-67

59 MANISH KUMAR 17-M-68

60 AVINASH KUMAR 17-M-69

61 AQUIB ALAM 17-M-70

62 SANJEET KUMAR 17-M-71

63 RASHMI KUMARI LE81

64 MANJEET KUMAR LE82

65 JITENDRA KUMAR LE83

66 KRISHNA KUMAR LE84

67 DIVAKAR SINGH LE85

68 ANURAG RAJ LE86

69 RAJESH KUMAR LE87

70 AKSHAY KUMAR VERMA LE88

71 ADITYA PRAKASH LE89

1. Scope and Objectives of the Course

5. To provide a useful foundation and basic knowledge of the subject required for innovative work

and advanced studies. Understand the basic principles of refrigeration and air conditioning

6. Analyze air refrigeration systems, vapor compression refrigeration systems, vapour

absorption refrigeration systems, and steam jet refrigeration systems

7. Study the psychometric properties of air and utilize the principles of psychometric in the

design of air conditioning equipment

8. Finally apply this knowledge for the design of refrigeration equipment and air conditioning

equipment

2. Textbooks

TB1: Refrigeration and air conditioning by C P Arora

TB2: Refrigeration and air conditioning by Manohar Prasad

TB3: Refrigeration and air conditioning by Jordon & Priester

3. Reference Books RB1: Refrigeration and air conditioning by Domkundwar

RB2: Refrigeration by Stoecker

Course Plan

Lecture

Number

Date of

Lecture

Topics Web Links for video

lectures

Text Book /

Reference

Book

1-6 Air refrigeration system TB3, RB1

Refrigeration machine, heat pump, coefficient of performance, ideal refrigeration cycle, Bell – Coleman, refrigeration cycle, open and closed systems, application of air-

https://www.youtube.

com/watch?v=OXIZh

qypNUI&list=PLE2D

A184A2E479885&in

dex=9

Institute / College Name : LOKNAYAK JAIPRAKASH INSTITUTE OF TECHNOLOGY, CHAPRA.

Program Name B.Tech MECHANICAL

Course Code ME1x20

Course Name REFRIGERATION AND AIRCONDITIONING

Lecture (per week): 4 Course Credits 3

Course Coordinator Name PIYUSH KUMAR PANDEY

refrigeration in air-crafts. 7-15 Various compression

systems: TB2, RB1

Simple vapour compression

refrigeration cycle, merits

and Refrigerants demerits of this system over air

refrigeration system, factors

affecting the performance of

a vapour compression

refrigeration system, sub

cooling and superheating of

vapour, wet and dry

compression, multistage

vapour compression system,

intercooler, flash chamber, accumulator and heat

exchanger.

https://www.youtube.

com/watch?v=x9yirfC

8niI&list=PLE2DA18

4A2E479885&index=

10

https://www.youtube.

com/watch?v=2B3Ds

UBYWVo&list=PLE

2DA184A2E479885

&index=12

16-20 Vapour absorption system: TB1, RB3

Simple and modified vapour absorption refrigeration system, Electrolux refrigerator, COP of heat operated refrigeration system.

https://www.youtube.

com/watch?v=wo2m

GZzFBj0&list=PLE2

DA184A2E479885&i

ndex=14

https://www.youtube.

com/watch?v=Ghp-

O1bMMuU&list=PL

E2DA184A2E479885

&index=15

21-24 Special refrigeration system

TB3, RB1

absorption, cascade, vortex, thermoelectric and steam jet refrigeration system.

https://www.youtube.co

m/watch?v=G8oW5KQ

HcvQ

25-27 Refrigerants TB3, RB2

classification and nomenclature of refrigerants, primary an d secondary refrigerants, properties of some common refrigerants, physical, chemical and thermodynamics properties, selection of refrigerants, leakage of refrigerants and methods of detection.

https://www.youtube.

com/watch?v=6_ePn_

LkIQM&list=PLE2D

A184A2E479885&in

dex=33

28 Equipment TB1, RB2

Elementary discussion of refrigerating equipment, ice plant and cold storage

https://www.youtube.

com/watch?v=NakOo

D-

G0IY&list=PLE2DA

184A2E479885&inde

x=20

https://www.youtube.

com/watch?v=UPsH2

fF7Igs&list=PLE2DA

184A2E479885&inde

x=26

29-33 Psychrometry TB1, RB1

Properties of air vapour mixture, wet bulb, dew point & dry bulb temperatures, humidity, specific humidity, humidity ratio, degree of saturation, relative humidity, total heat psychrometric relation, psychometric charts and its uses, psychometric processes evaporative cooling.

https://www.youtube.

com/watch?v=qAOJz

p7ckGo&list=PLE2D

A184A2E479885&in

dex=34

34-43 Air conditioning TB1, RB1

General principle and requirement for comfort and air conditioning, thermodynamics of human body, estimation of heating and cooling loads, capacity of cooling coils, humidification and dehumidification unit and conditioner, central air conditioner, year around air condition, humidity and temperature control, industrial application of air conditioning system.

https://www.youtube.

com/watch?v=nvUhi

XD63Eg&list=PLE2

DA184A2E479885&i

ndex=38

1. Evaluation Scheme:

Component 1 Mid Semester Exam 20

Component 2 Assignment Evaluation 10

Component 3** End Term Examination** 70

Total 100

** The End Term Comprehensive examination will be held at the end of semester. The mandatory

requirement of 75% attendance in all theory classes is to be met for being eligible to appear in this

component.

SYLLABUS

Topics No of lectures Weightage

Air refrigeration system: Refrigeration machine, heat pump,

coefficient of performance, ideal refrigeration cycle, Bell – Coleman,

refrigeration cycle, open and closed systems, application of air-

refrigeration in air-crafts.

6 14%

Various compression systems: Simple vapour compression refrigeration cycle, merits and Refrigerants demerits of this system over air refrigeration system, factors affecting the performance of a vapour compression refrigeration system, sub cooling and superheating of vapour, wet and dry compression, multistage vapour compression system, intercooler, flash chamber, accumulator and heat exchanger.

8 19%

Vapour absorption system: Simple and modified vapour

absorption refrigeration system, Electrolux refrigerator, COP of heat operated refrigeration system.

5 12%

Special refrigeration system: absorption, cascade, vortex,

thermoelectric and steam jet refrigeration system. 4 10%

Refrigerants: classification and nomenclature of refrigerants,

primary and secondary refrigerants, properties of some common

refrigerants, physical, chemical and thermodynamics properties,

selection of refrigerants, leakage of refrigerants and methods of

detection.

3 7%

Equipment: Elementary discussion of refrigerating equipment, ice

plant and cold storage

1 3%

Psychrometry: Properties of air vapour mixture, wet bulb, dew

point & dry bulb temperatures, humidity, specific humidity,

humidity ratio, degree of saturation, relative humidity, total heat

psychrometric relation, psychometric charts and its uses,

psychometric processes evaporative cooling.

5 11%

Air conditioning: General principle and requirement for comfort

and air conditioning, thermodynamics of human body, estimation of

heating and cooling loads, capacity of cooling coils, humidification

and dehumidification unit and conditioner, central air conditioner,

year around air condition, humidity and temperature control,

industrial application of air conditioning system.

10 24%

This Document is approved by:

Designation Name Signature

Course Coordinator Mr. PIYUSH KUMAR PANDEY

H.O.D Mr. Kumar Jyotiraditya

Principal Dr. S. N. Sharma

Date

Evaluation and Examination Blue Print:

Internal assessment is done through quiz/class test, assignments and sessional test. One set of question

paper is asked from concern faculty and that question paper is chosen for the examination. Examination

rules and regulations are uploaded on the student’s portal. Evaluation is a very transparent process and

the answer sheets of sessional tests are shown to the students and internal assessment

assignments/Quiz/Class Test are returned back to the students.

The components of evaluations along with their weightage followed by the University is given below

Sessional Test 20%

Assignments/Quiz/Class Tests/Attendance 10%

End term examination 70%

LECTURE PLAN

Topics Lecture Number

Air refrigeration system 1-6

Refrigeration, refrigerator, heat pump, coefficient of performance

Reversed carnot cycle, ideal refrigeration cycle, open and closed system

Various compression system 7-14

Simple air refrigeration system, bootstrap refrigeration system

Regenerative and reduced ambient air refrigeration system

Vapour compression refrigeration, TS and Ph diagram

Factors affecting performance of vapour compression

Wet and dry compression, subcooling, expansion valve,

Compound vapor compression system,

Intercooler, flash chamber, heat exchanger

Vapour absorption system 14-18

VARS, COP of VARS

Modified VARS, Ammonia water absorption system,

Electrolux refrigerator

Special refrigeration system 19-22

Cascade refrigeration system

Vortex refrigeration

Thermoelectric refrigeration

Steam refrigeration system

Refrigerants 23-26

What is refrigerants, classification, nomenclature of refrigerants,

Desirable properties of refrigerants, physical, chemical, thermodynamic

Leakage of refrigerants and leak detection methods

Psychrometry 27-32

What is psychrometry, moist air, specific humidity, relative humidity,

DBT,WBT,DPT, enthalpy of moist air

Psychrometric process- sensible heating, cooling, humidification, dehumidification

Psychrometry charts and usage.

Air conditioning 33-42

Institute / School Name : Loknayak Jai Prakash Institute of Technology, Chapra

Program Name B.Tech Mechanical Engineering

Course Code ME1x20

Course Name Refrigeration and Airconditioning

Lecture / Tutorial (per week): 3/0 Course Credits 3

Course Coordinator Name Piyush Kumar Pandey

Application of airconditioning, comfort air conditioning and its types, human comfort

Estimation of cooling load heating load, capacity of cooling coil

Central air conditioning, humidity and temperature control

Industry application of air conditioning system

LOKNAYAK JAI PRAKASH INSTITUTE OF TECHNOLOGY,

CHAPRA

MID TERM EXAMINATION 2018

SUBJECT: REFRIGERATION & AIR CONDITIONING ROLL NO.

BRANCH: MECHANICAL ENGINEERING SEMESTER: VII

TIME: 2 HOURS MAXIMUM MARKS: 20

Instructions

(i) Attempt all section.

(ii) Marks are indicated on the right-hand margin.

Section A

1. For each questions given below select the correct answer and write in your answer sheet. 5x1

(i) In a vapour compression refrigeration cycle for making ice, the condensing temperature for

higher COP

(a) should be near the critical temperature of refrigerant

(b) should be above the critical temperature of refrigerant

(c) should be much below the critical temperature of refrigerant

(d) could be any value as it does not affect the COP

(ii) The coefficient of performance of a refrigerator working on a reversed Carnot cycle is 4. The

ratio of the highest absolute temperature to the lowest absolute temperature is:

(a) 1.2 (b) 1.25 (c) 3.33 (d) 4

(iii) For simple vapour compression cycle, enthalpy at suction = 1600 kJ/kg, enthalpy at discharge

from the compressor = 1800 kJ/kg, enthalpy at exit from condenser = 600 kJ/kg. What is the COP

for this refrigeration cycle?

(a) 3·3 (b) 5·0 (c) 4 (d) 4·5

(iv) The leakage in a Freon-based refrigeration system can be detected by using a/an

(a)Oxy-acetylene torch (b) Halide torch

(c)Sulphur torch (d) Blue litmus paper

(v) Chemical formula of refrigerant R22 is:

(a) CH ClF2 (b) C2 Cl3 F3 (c) C2 Cl2 F4 (d) C2 H2 F4

Section B

2+3

2.a) Why isentropic expansion is not preferable in Vapour compression refrigeration cycle?

b) What is the difference between a refrigerator and a heat pump? Find the relation between

COP of heat pump and COP of refrigerator if both are running on reversed carnot cycle

between same temperature limit.

OR

1+2+2

3. a) Explain the term tonne of refrigeration.

b) Why isenthalpic expansion is not used in reversed Brayton cycle ?

c) Discuss the effect of superheating and sub-cooling on VCRS

Section C

1+2+2

4. a) Draw the bell coleman cycle on PV & TS diagram.

b) Explain dry & wet compression.

c) In a 5kW cooling capacity refrigeration system operating on simple VCRS, refrigerant enters the

evaporator with an enthalpy of 75kJ/kg and leaves the evaporator with an enthalpy of 75kJ/kg. the

compression is isentropic and enthalpy at the outlet of compressor is 210 kJ/kg. Find out the

COP and power consumption in kW.

OR

2+1+2

5. a) What do you understand by DART? Show the comparision of DART vs. Mach number variation

for common refrigeration system.

b) Write down the COP of cascade refrigeration system.

c) A refrigerant operating on simple VCRS having a COP of 6.5 and enthalpy of saturated liquid

and saturated vapour refrigerant at the operating condenser temperature of 35oC are 69.55kJ/kg

and 201.5kJ/kg respectively. The saturated refrigerant vapour leaving the evaporator having the

enthalpy of 187.53 kJ/kg. The specific heat of vapour refrigerant is 0.6155 kJ/kg. Then find out

the compressor discharge temperature in oC.

Section D

5

6. Air is used as a refrigerant in a reversed Brayton cycle. It enters the compressor at a pressure of 1

bar, temperature of 10oC and it is then compressed to a pressure of 5 bar. Air is then cooled in the

cooler to a temperature of 25oC. Determine

(i) Theoretical COP

(ii) RE/kg, assuming both compression and expansion are to be isentropic

(iii) If compression will follow PV1.35=C and expansion will follow PV1.3=C then

determine COP and RE/kg.

OR

5

7. Air enters the compressor at pressure of 0.1 MPa and a temperature of 277K. It is then

compressed to a pressure of 300kPa with an isentropic efficiency of 72%. It is then cooled in a

cooler to a temperature of 55oC and then expanded to a pressure of 100kPa with isentropic

efficiency of 78%. Assuming air to be an ideal gas and the lower temperature air absorbs a

cooling load of 3TR. Determine

(i) Mass flow rate in kg/s

(ii) Power consumption in kW

(iii) COP