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Thermal Engineering-I Course code: 3341902

GTU/NITTTR/Bhopal/13-14 Gujarat State

1

GUJARAT TECHNOLOGICAL UNIVERSITY, AHMEDABAD, GUJARAT

COURSE CURRICULUM

COURSE TITLE: THERMAL ENGINEERING- I

(Code: 3341902)

Diploma Programme in which this course is offered Semester in which offered

Mechanical Engineering 4th

Semester

1. RATIONALE

In industry, the mechanical engineers are supposed to operate and maintain thermal

equipment. This course will provide the basic knowledge of thermal engineering

which will function as foundation in applications in major fields of mechanical

engineering and technology notably in steam and nuclear power plants. This course

would develop knowledge and skills related to boilers, boiler mountings and

accessories, compressors, heat exchangers, steam turbines etc. This course is thus very

important for mechanical engineers.

2. COMPETENCY

The course content should be taught with the aim to develop different types of skills

so that students are able to acquire following competency:

Apply basic concepts, laws and principles of thermal engineering to operate

and maintain equipment, devices and machines working in mechanical

engineering systems.

3. COURSE OUTCOMES

The theory should be taught and practical should be carried out in such a manner that

students are able to acquire different learning out comes in cognitive, psychomotor

and affective domain to demonstrate following course outcomes.

i. Determine steam properties and dryness fractions.

ii. Classify and explain boilers, boiler mountings and accessories.

iii. Determine boiler performance based on given specific parameters.

iv. Explain working of steam prime movers.

v. Identify the elements and processes of steam condensers and cooling towers.

vi. Operate air compressors and observe the parameters affecting the performance.

vii. Calculate heat transfer for given heat transfer system.

4. TEACHING AND EXAMINATION SCHEME

Teaching Scheme

(In Hours)

Total Credits

(L+T+P)

Examination Scheme

Theory Marks Practical Marks Total

Marks

L T P C ESE PA ESE PA

150 3 0 2 3 70 30 20 30

Legends: L -Lecture; T -Tutorial/Teacher Guided Student Activity; P -Practical; C - Credit; ESE-End

Semester Examination; PA -Progressive Assessment



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5. COURSE DETAILS

Unit Major Learning

Outcomes

Topics and Sub-topics

Unit – I

Two phase system

1a. Describe steam

formation process and

terminology.

1.1 Concept of two phase system.

1.2 Formation of steam, its various

phases, definition and representation

of wet steam, dry steam, saturated

steam and superheated steam on PV,

T-s and H-s diagram.

1.3 Concept and determination of dryness

fraction and degree of superheat.

1.4 Concept and determination of latent

heat, sensible heat, enthalpy, entropy

and specific volume of steam.

1b. Use steam table and

Mollier chart for

determination of

steam property.

1.5 Use of Steam tables and Mollier

chart- (Heat Entropy Chart).

1.6 Numerical examples based on

above.(1.1 to 1.5).

1c. Determine dryness

fraction of steam.

1d. Explain throttling

process.

1.7 Throttling process.

1.8 Methods of measurement of steam

quality, Calorimeters- Bucket,

Separating, Throttling and Combined

calorimeters. (No numerical

Problems).

Unit – II

Boilers, mountings

and accessories

2a. Explain the working

of boilers, mountings

and accessories.

2.1 Steam boiler-concept, definition as

per Indian Boilers Regulation (IBR),

functions, features and classification.

2.2 Working, merits and demerits of

following low pressure steam boilers:

i. Simple vertical boiler.

ii. Lancashire boiler.

iii. Cornish boiler.

iv. Cochran boiler.

v. Babcock and Wilcox water

tube boiler.

vi. Packaged boiler.

vii. Waste heat recovery boiler.

2.3 Boiler mountings and accessories-

functions, working and location on

boilers.

2.4 Boiler draught system-concept and

classification.

2b.Determine boiler

performance.

2.5 Boiler performance – parameters,

evaporative capacity, equivalent

evaporation, efficiency, heat balance

sheet, simple numerical examples

based on these.

2.6 Concept of fluidized bed combustion



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Unit Major Learning

Outcomes


boilers.

2.7 Maintenance, inspection and safety

precautions in boiler house (As per

IBR), check list in boilers.

Unit – III

Steam prime

movers

3a.Explain principle of

working and

construction of Steam

turbine.

3b.Apply principle of

steam nozzles to solve

simple examples.

3.1 Concept and classification of prime

movers.

3.2 Steam nozzles-types, working and

applications. Mass and velocity of

steam discharge through nozzle (No

derivation). Simple examples.

3.3 Steam turbine – concept and

classification. Impulse and reaction

turbines (constructional and materials

details.)-working and differences.

3c.Describe

compounding of steam

turbine.

3.4 Compounding of steam turbine:

i. Need.

ii. Pressure compounding.

iii. Velocity compounding.

iv. Pressure velocity

compounding.

Unit – IV

Steam condensers

and cooling towers

4a.Describe working of

condensers.

4.1 Elements of a steam condensing

plant, concept, function and

classification of condensers.

4.2 Jet condensers and surface

condensers- constructional sketch,

working and differences.

4b.Determine efficiency

of condensers.

4.3 Vacuum efficiency and condenser

efficiency of condensers- simple

numerical example.

4c.Describe working of

cooling towers.

4.4 Classification, function and working

of cooling towers.

Unit – IV

Air compressors

5a.Explain principle,

construction and

working of air

compressors.

5.1 Air compressor-concepts, functions,

classification and applications.

5.2 Working of reciprocating air

compressor and rotary air

compressors.

5.3 Single stage air compressor and

multistage air compressor:

i. Working.

ii. Inter-cooling & after cooling. 5b.Calculate power

requirement and volumetric efficiency of reciprocating air compressor.

5.4 Power required and efficiency of reciprocating air compressors-single and two stages, simple numerical examples.

5.5 Concept of screw compressors for oil free air.



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Unit Major Learning

Outcomes


Unit – V

Heat transfer

6a.Explain modes of heat transfer.

6b.Determination of heat transfer through cylinder and wall.

6.1 Various modes of heat transfer. 6.2 Conduction heat transfer- Fourier’s

law- explanation (No Cartesian or other equation derivation), thermal conductivity, heat transfer through a plain wall, composite wall and cylinder.

6.3 Convection heat transfer, Newton’s law of convection, Free and force convection, coefficient of convection.

6.4 Radiation heat transfer, Blackbody concept, emissivity, refractivity, absorptivity, Stefan and Boltzmann’s law.

6c.Explain types of insulations.

6.5 Define thermal conductivity. 6.6 Need, types, properties and

applications of insulating materials in various industries.

6.7 Difference between hot and cold insulation.

6d.Calculate overall heat transfer coefficient and LMTD.

6.8 Over all heat transfer coefficient. 6.9 Simple numerical examples based on

above. 6.10 Heat exchanger: introduction, types

and applications- Logarithmic Mean Temperature Difference (LMTD) concept- (No derivation & no numerical examples).

6. SUGGESTED SPECIFICATIONTABLE WITH HOURS & MARKS (THEORY)

Unit Unit Title

Teaching

Hours

Distribution of Theory Marks

R

Level

U

Level

A

Level

Total

Marks

I Two phase system 7 2 4 4 10

II Boilers, mountings and accessories 10 7 4 4 15

III Steam prime-movers 6 4 4 2 10

IV Steam condenser & cooling towers 3 2 3 2 07

V Air compressors 8 3 6 5 14

VI Heat transfer 8 3 4 7 14

Total 42 21 25 24 70

Legends: R = Remember; U = Understand; A = Apply and above levels (Bloom’s revised taxonomy).

Note: This specification table shall be treated as a general guideline for students and teachers. The

actual distribution of marks in the question paper may vary slightly from above table.

General Notes:

a. If midsem test is part of continuous evaluation, unit numbers I, II (UP TO 2.4

ONLY) and VI are to be considered.



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b. Ask the questions from each topic as per marks weightage. Numerical questions

are to be asked only if it is specified. Optional questions must be asked from the

same topic.

7. SUGGESTED LIST OF EXERCISES/PRACTICALS

The practical/exercises should be properly designed and implemented with an attempt to

develop different types of skills (outcomes in psychomotor and affective domain) so

that students are able to acquire the competencies/programme outcomes. Following is the

list of practical exercises for guidance.

Note: Here only outcomes in psychomotor domain are listed as practical/exercises.

However, if these practical/exercises are completed appropriately, they would also lead

to development of certain outcomes in affective domain which would in turn lead to

development of Course Outcomes related to affective domain. Thus over all development

of Programme Outcomes (as given in a common list at the beginning of curriculum

document for this programme) would be assured.

Faculty should refer to that common list and should ensure that students also acquire

outcomes in affective domain which are required for overall achievement of Programme

Outcomes/Course Outcomes.

S.

No.

Unit

No.

Practical Exercises

(Outcomes’ in Psychomotor Domain) Hrs.

required

1 I

Preparatory Activity:

a. List and define thermodynamic properties.

b. Tabulate thermodynamic SI units and their conversions.

c. Explain thermodynamic processes and their examples.

d. Given the data, determine properties of steam using steam

table and Mollier chart.

02

2 II

Demonstration:

(Video/ Movie/Cut Sections /Models may be used in absence of

Required Machine/ Equipment/ Device.):

a. Steam boilers.

b. Boiler mountings and accessories.

04

3 II

Boiler Performance:

Boiler trial- determination of boiler efficiency, equivalent

evaporation and Heat balance sheet.

(Based on in-house performance or from the data collected during

industrial visit.).

04

4 III

Demonstration:



a. Steam prime movers-impulse and reaction turbines.

b. Working of nozzles.

02

5 IV Demonstration:



02



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a. Steam condensers.

b. Cooling towers.

6 V Performance Test of Air Compressor:

Performance test on a reciprocating air compressor and determine

its volumetric efficiency.

04

7 VI Performance Test of Heat Exchanger:

Determine overall heat transfer coefficient and LMTD of heat

exchanger.

02

8 ALL

Mini Project And Presentation: (In the group of 3-5students- to

be assigned in the beginning of the term).

a. Identify any one thermal equipment/device/plant

(which are included in syllabus) at nearby industry. Sketch

the setup, write the specifications, and describe the

working of that with process parameters and state

applications of that.

b. Downloaded photos/ videos, PPTs. Make one CD/DVD for

a batch of students. Also prepare a chart or model on given

topic. Prepare the seminar. Topics related to syllabus are to

be given by teacher. Advancement in the topics areas may

also be given.

c. Present the seminar at least for 10 minutes for a and b

above.This must include photographs / movies of group

working on project.

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TOTAL 28

Notes:

a. It is compulsory to prepare log book of exercises. It is also required to get each

exercise recorded in logbook, checked and duly dated and signed by teacher.

b. Term work report must not include any photocopy/ies, printed manual/pages,

litho, etc. It must be hand written / hand drawn by student only.

c. Term work report content of each experience should also include following.

i. Experience set up sketch and specifications of boilers, mountings,

accessories, condensers, cooling towers, air compressors, heat

exchangers, etc (as applicable).

ii. Working for demonstration type experiences.

iii. Steps / process description to execute experience for performance type

experience.

iv. Observation table, calculation and graphs if necessary.

d. Mini project and presentation topic/area has to be assigned to the student in the

beginning of the term by batch teacher. This may be assigned individually or in

the group of maximum 3 to 5students.

e. Student activities are compulsory and to be submitted along with term work.

e. For ESE, students are to be assessed for competencies achieved through

suggested list of activities/ practical. They should be given following tasks:

i. Identify the parts of equipment (Air compressor/ boiler/heat

exchanger/ condenser).

ii. Identify location and function of boiler mountings/ accessories

(any two).



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iii. Use of steam table/ Mollier chart, determine properties of steam

for given pressure and temperature (two problems).

iv. Any one performance test (for one set of reading) on heat

exchanger/ air compressor/ boiler (determine heat supplied and

any one heat loss).

8. SUGGESTED LIST OF STUDENT ACTIVITIES

Sr. No. Activity

1 Prepare Mollier charts and show different regions.

2

Collect/ download product catalogues with specification of various types of

energy conservation equipment/ devices and heat exchanger of recent

trends.

3

At least one visit of any power plant/ industry where various items like

boiler, air compressor, heat exchanger, cooling tower, condenser etc. can

be shown to students.

4

Identify and list at least 10 equipments/devices which require heat transfer

and prevention of heat transfer. Also state mode of heat transfer and

methods used to prevent heat transfer.

9. INSTRUCTIONAL STRATEGIES

Sr. No. Unit Unit Title Strategies

1 I Two Phase system

Charts, PPTs, demonstration of the

process.

2 II Boilers, mountings

and accessories

Models, Charts, Videos, PPTs, Industrial

visit.

3 III Steam prime-movers,

condensers and

cooling towers

Models, Charts, Videos, Cut sections,

Industrial visit.

4 IV Air compressors Charts, Videos, PPTs.

5 V Heat transfer Charts, Videos, PPTs.

10. SUGGESTED LEARNING RESOURCES

(A) List of Books:

Sr.No. Title of Books Author Publication

1. Heat Engines Pandya and Shah Charotar Publishing

House

2. Thermodynamics and Heat power

Engg.

Mathur and Mehta Tata Mcgraw- Hill

3. Heat Engines D. A. Wrangham Cambridge

University Press

4. Heat and mass transfer D S Kumar S K Kataria & Sons

6. Thermal Engineering P.L.Ballaney Khanna.Publishers

7. Thermal Engineering A. S. Sarao SatyaPrakashan



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8. Heat and mass transfer R K Rajput S. Chand

9. Basic Boiler Attendant M MDalchawal New Popular

Prakashan

10. Thermal Engineering R K Rajput Laxmi.Publications

11. Practical Thermodynamics G D Rai Khanna Publisher

12. A Text book of Thermal

Engineering

R S Khurmi& J K

Gupta S Chand & Co.

(B) List of major equipment/materials:

i. Working non IBR steam boiler of package type.

ii. Cut section/ models of boilers, boiler mountings and accessories.

iii. Cut section/ models of steam prime movers.

iv. Test rigs of condensers and cooling towers.

v. Test rig of reciprocating air compressor.

vi. Experimental setup of heat exchanger.

vii. Independently temperature and pressure measuring instruments.

(C) List of Software/Learning Websites

i. http://nptel.iitm.ac.in/courses/112101097/

ii. http://nptel.iitm.ac.in/courses/112106155/

iii. http://nptel.iitm.ac.in/courses/112101002/

http://www.thermaxindia.com/Large-Industrial-Boilers/Waste-Heat

Recovery-Boiler.aspx

v. http://www.thermaxindia.com/Packaged-Boilers/Shell-Boiler/Oil-Gas-

Fired/Shellmax.aspx

vi. http://www.thermaxindia.com/Large-Industrial-Boilers/solid-fuels-

agro-wastes-biomass/Biomass-Fired-Boiler.aspx

vii. http://www.bhel.com/product_services/range.php?rangeid=146&produ

ctid=106&categoryid=141

viii. http://www.bhel.com/product_services/product.php?categoryid=62&lin

k=Power

11. COURSE CURRICULUM DEVELOPMENT COMMITTEE

Faculty Members from Polytechnics.

Prof. S. R. Pareek, Head of Department, Mechanical Engineering, Tolani F.

G. Polytechnic, Adipur.

Prof. Patel Ramanbhai Revabhai, Lecturer in Mechanical Engineering, R.

C. Technical Institute, Sola, Ahmedabad.

Dr. Shah Atul S., Lecturer in Mechanical Engineering, Government

Polytechnic Waghai.

Prof. M. N. Patel, Lecturer in Mechanical Engg, Government Polytechnic,

Chhotaudepur.

http://nptel.iitm.ac.in/courses/112101097/



http://www.thermaxindia.com/Large-Industrial-Boilers/Waste-HeatRecovery-Boiler.aspx

http://www.thermaxindia.com/Large-Industrial-Boilers/Waste-HeatRecovery-Boiler.aspx

http://www.thermaxindia.com/Packaged-Boilers/Shell-Boiler/Oil-Gas-Fired/Shellmax.aspx

http://www.thermaxindia.com/Packaged-Boilers/Shell-Boiler/Oil-Gas-Fired/Shellmax.aspx

http://www.thermaxindia.com/Large-Industrial-Boilers/solid-fuels-agro-wastes-biomass/Biomass-Fired-Boiler.aspx

http://www.thermaxindia.com/Large-Industrial-Boilers/solid-fuels-agro-wastes-biomass/Biomass-Fired-Boiler.aspx

http://www.bhel.com/product_services/range.php?rangeid=146&productid=106&categoryid=141

http://www.bhel.com/product_services/range.php?rangeid=146&productid=106&categoryid=141

http://www.bhel.com/product_services/product.php?categoryid=62&link=Power

http://www.bhel.com/product_services/product.php?categoryid=62&link=Power



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Prof. Patadiya Virenkumar Natvarlal, Lecturer in Mechanical Engineering,

Shree N. M. Gopani Polytechnic Institute, Ranpur.

Prof. Ms. Prajapati KrutikaVinodchandra, Lecturer in Mechanical

Engineering, Parul Institute of Engineering & Technology (Diploma Studies),

Limda, Waghodia.

Coordinator and Faculty Members from NITTTR Bhopal

1. Dr. Vandana Somkuwar, Associate Professor, Department of Mechanical

Engineering.

2. Prof. C.K. Chugh, Professor, Department of Mechanical Engineering.

Academic Laxmi Institute of Technology, Sarigam

Diploma Mechanical Engineering Year: 2018-19

Name of Faculty : Mr. Mahipal A. Parmar/ Ms.Ketul Shah

Name of Subject :THERMAL ENGINEERING-I

Subject Code : 3341902

Assignment: 1

Two phase system

Sr. No. Name of Question Remarks

1 Describe the various stages of Formation of steam.

2 Define dryness fraction, quality of steam and degree of superheat.

3 Define latent heat, sensible heat, enthalpy, entropy and specific volume of steam.

4 What are the methods of measurement of dryness fraction of steam?

5 Explain Throttling calorimeter.

6 With the help of steam table find the values of entropy of water, entropy of evaporation and entropy of dry saturated steam at 5 bar, 8 bar, 12 bar, 15 bar and 20 bar, 250C, 800c.

7 2 kg of steam at 10 bar and 0.9 dryness fraction is converted into superheated steam with 500C as degree of super heat. Find the change of enthalpy. Given Cp =2.0 kJ/kg K.

8 Find enthalpy, entropy and volume of 10 kg steam at 12 bar and 0.85 dryness fraction



Assignment: 2

Boilers, mountings and accessories

Sr. No.

Name of Question Remarks

1.

Define 1) Boiler 2) Boiler Mountings 3.) Boiler Accessories 4) Draft or Draught

2. State the function of economizer and fusible plug .

3. List five industrial applications of steam.

4. List advantages and disadvantages of Lancashire boiler

5. Differentiate between Boiler mountings and accessories.

6. Explain Bourdon tube pressure gauge with neat sketch.

7. Explain water level indicator with neat sketch.

8. Explain steam stop valve with neat sketch.

9. Mention the function of Economiser and Air Pre-heater

10. Define :evaporative capacity, equivalent evaporation, efficiency

11. Explain the concept of fluidized bed combustion

12. Explain Babcock-Wilcox boiler with neat sketch.

13. Explain Simple vertical boiler with neat sketch.

14. Explain Cochran boiler with neat sketch.

15. Explain the Boiler draught system-concept and classification.



16. State four differences between Natural draft and Artificial draft in steam boiler.

17.

During a boiler trial following data are available:- Coal used= 500 kg/hr Mass of dry flue gas= 22.5 kg/kg of coal Calorific value of coal= 31000 kj/kg-k Flue gas temp= 310 degree c Cp of flue gas= 1.008 kj/kg Cp of steam= 1.89 kj/kg Boiler room temp= 18 degree c Feed water temp= 79 degree c Dry saturated steam generated= 4700 kg/hr Steam pressure= 12 bar Atmospheric pressure= 1 bar Prepare the heat balance sheet / kg of coal burnt..

18. Draw and explain a sample heat balance sheet of boiler.



Assignment: 3

Steam Prime movers


1. State concept of steam prime-movers.

2. Define and classify prime movers.

3. Define the different types of steam nozzles.

4. Give the expression for discharge through nozzle.

5. List five applications of steam nozzles.

6. Differentiate between reaction and impulse turbine.

7. Explain working principle of Impulse steam turbine with neat sketch.

8. Write short note on Compounding of steam turbines. Give the need and types.

9.

Explain :- 1 )pressure compounding of steam turbines. 2) Velocity compounding of steam turbines. 3) Pressure-Veloicity compounding of steam turbines.

10. State advantages and disadvantages of velocity compounding.



Assignment: 4

Steam condenser and cooling tower


1. State the function of condenser and cooling tower in a steam power plant.

2. Explain the Surface Condenser with neat sketch.

3. Differentiate between jet condenser and surface condenser.

4. Explain jetcondenser. state its limitation.

5. State advantage and limitation of jet condenser.

6. State the function of various parts of surface condenser.

7. Give Classification of cooling towers.

8. State purpose of cooling tower. Explain any one of the cooling tower.

9. What is the source of air leakage in steam condenser?

10. State the methods for detection of air leakage in Condenser.




Assignment:5

Air compressor

Sr. No.


1.

Define 1.) Compressor 2.) indicated power 3) Shaft or brake power 4) swept volume 5) clearance volume 6) Volumetric efficiency 7) Free Air Delivered (FAD)

2. State four differences between Reciprocating and Rotary air compressors.

3. Give the detail classification of Air compressor.

4. State advantages of centrifugal compressors

5. What is multistage compressor? State advantages of multistage air compression.

6. With the help of p-v diagram, explain inter-cooling in 2 - stage air Compression.

7. State four applications of compressed air.

8. Derive the equation for work required in case of single stage reciprocating compressor.

9. Derive the equationfor work required in case of two stage reciprocating compress or Statethe assumption made.

10. State the types of rotary air compressor and explain any one type of air compressor.

11. Define the following terms with reference to air compressor. 1] isothermal efficiency 2] free air delivered

12. Derive equation for volumetric efficiency of a single stage reciprocating compressor.

13. Compare rotary and reciprocating compressor. Differentiate between root blower and wane blower.

14. Explain the effect of clearance on reciprocating compressor.



Assignment: 6

Heat Transfer Sr. No.


1.

Define: 1) conduction 2]convection 3) Radiation 4) Thermal conductivity 5) Emissivity

2. Define the term absorptive, reflectivity and transitivity.

3. State four properties of good insulators

4. State the types of heat exchangers. Describe any one type of heat exchanger with sketch

5. State the relationship between emissivity and absorptivity of a surface.

6. Explain the different method of heat transfer.

7. Explain in brief: (1) Stefan-Boltzmann’s law of total radiation (2) Fourier’s Law of Conduction

8. Explain the Concept of Black Body.

9. Differentiate between Free convection and Forced convection

10. Define “Heat exchanger”. With the help of neat sketches explain in brief the Parallel flow, counter flow and cross flow heat exchangers.

11. Define overall heat transfer coefficient.

12.

Internal surface of wall is at 9000 degree c temp. wall is 60 cm thick, 1 m length, and 1.5 m width. Thermal conductivity of wall is 0.4 watt/m-k. find thermal resistance and heat transfer rate of wall. Temperature of outside surfaces of wall is 200 degree c.

Laxmi Institute of Technology , Sarigam Approved by AICTE, New Delhi; Affiliated to Gujarat Technological

University, Ahmadabad Academic Year : 2018-2019

Question Bank

Department: DE MECHANICALENGINEERING Name of Subject In charge:

MR.MAHIPAL A.PARMAR

Subject Name: THERMAL ENGINEERING-I Subject Code: 3341902 Academic Year: 2018-2019 Semester: 4TH

Sr. No. Name of Question

1. Describe the various stages of Formation of steam.

2. Define dryness fraction, quality of steam and degree of superheat.

3. Define latent heat, sensible heat, enthalpy, entropy and specific volume of steam.

4. What are the methods of measurement of dryness fraction of steam?

5. Explain Throttling calorimeter.

6. With the help of steam table find the values of entropy of water, entropy of evaporation and entropy of dry saturated steam at 5 bar, 8 bar, 12 bar, 15 bar and 20 bar, 250C, 800c.

7.

2 kg of steam at 10 bar and 0.9 dryness fraction is converted into superheated steam with 500C as degree of super heat. Find the change of enthalpy. Given Cp =2.0 kJ/kg K.

8. Find enthalpy, entropy and volume of 10 kg steam at 12 bar and 0.85 dryness fraction

9.

Define 1) Boiler 2) Boiler Mountings 3.) Boiler Accessories 4) Draft or Draught

10. State the function of economizer and fusible plug .



11. List five industrial applications of steam.

12. List advantages and disadvantages of Lancashire boiler

13. Differentiate between Boiler mountings and accessories.

14. Explain Bourdon tube pressure gauge with neat sketch.

15. Explain water level indicator with neat sketch.

16. Explain steam stop valve with neat sketch.

17. Mention the function of Economiser and Air Pre-heater

18. Define :evaporative capacity, equivalent evaporation, efficiency

19. Explain the concept of fluidized bed combustion

20. Explain Babcock-Wilcox boiler with neat sketch.

21. Explain Simple vertical boiler with neat sketch.

22. Explain Cochran boiler with neat sketch.

23. Explain the Boiler draught system-concept and classification.

24. State four differences between Natural draft and Artificial draft in steam boiler.

25.

During a boiler trial following data are available:- Coal used= 500 kg/hr Mass of dry flue gas= 22.5 kg/kg of coal Calorific value of coal= 31000 kj/kg-k Flue gas temp= 310 degree c Cp of flue gas= 1.008 kj/kg



Cp of steam= 1.89 kj/kg Boiler room temp= 18 degree c Feed water temp= 79 degree c Dry saturated steam generated= 4700 kg/hr Steam pressure= 12 bar Atmospheric pressure= 1 bar Prepare the heat balance sheet / kg of coal burnt..

26. Draw and explain a sample heat balance sheet of boiler.


28. Define and classify prime movers.

29. Define the different types of steam nozzles.

30. Give the expression for discharge through nozzle.

31. List five applications of steam nozzles.

32. Differentiate between reaction and impulse turbine.

33. Explain working principle of Impulse steam turbine with neat sketch.

34. Write short note on Compounding of steam turbines. Give the need and types.

35.

Explain :- 1 )pressure compounding of steam turbines. 2) Velocity compounding of steam turbines. 3) Pressure-Veloicity compounding of steam turbines.

36. State advantages and disadvantages of velocity compounding.


38. Explain the Surface Condenser with neat sketch.



39. Differentiate between jet condenser and surface condenser.

40. Explain jetcondenser. state its limitation.

41. State advantage and limitation of jet condenser.

42. State the function of various parts of surface condenser.

43. Give Classification of cooling towers.

44. State purpose of cooling tower. Explain any one of the cooling tower.

45. What is the source of air leakage in steam condenser?

46. State the methods for detection of air leakage in Condenser.


48.

Define 1.) Compressor 2.) indicated power 3) Shaft or brake power 4) swept volume 5) clearance volume 6) Volumetric efficiency 7) Free Air Delivered (FAD)

49. State four differences between Reciprocating and Rotary air compressors.

50. Give the detail classification of Air compressor.

51. State advantages of centrifugal compressors

52. What is multistage compressor? State advantages of multistage air compression.



53. With the help of p-v diagram, explain inter-cooling in 2 - stage air

Compression.


55. Derive the equation for work required in case of single stage reciprocating compressor.

56. Derive the equationfor work required in case of two stage reciprocating compress or Statethe assumption made.

57. State the types of rotary air compressor and explain any one type of air compressor.

58. Define the following terms with reference to air compressor. 1] isothermal efficiency 2] free air delivered

59. Derive equation for volumetric efficiency of a single stage reciprocating compressor.

60. Compare rotary and reciprocating compressor. Differentiate between root blower and wane blower.

61. Explain the effect of clearance on reciprocating compressor.

62.

Define: 1) conduction 2]convection 3) Radiation 4) Thermal conductivity 5) Emissivity

63. Define the term absorptive, reflectivity and transitivity.

64. State four properties of good insulators

65. State the types of heat exchangers. Describe any one type of heat exchanger with sketch

66. State the relationship between emissivity and absorptivity of a surface.

67. Explain the different method of heat transfer.



68.

Explain in brief: (1) Stefan-Boltzmann’s law of total radiation (2) Fourier’s Law of Conduction

69. Explain the Concept of Black Body.

70. Differentiate between Free convection and Forced convection

71. Define “Heat exchanger”. With the help of neat sketches explain in brief the Parallel flow, counter flow and cross flow heat exchangers.

72. Define overall heat transfer coefficient.

73.

Internal surface of wall is at 9000 degree c temp. wall is 60 cm thick, 1 m length, and 1.5 m width. Thermal conductivity of wall is 0.4 watt/m-k. find thermal resistance and heat transfer rate of wall. Temperature of outside surfaces of wall is 200 degree c.

Laxmi Institute of Technology, Sarigam Approved by AICTE, New Delhi; Affiliated to Gujarat Technological University, Ahmedabad

Academic Year 2018-19 Centre Code: 691 Examination : Mid Semester Examination- I Branch: MECHANICAL Semester: 4th Sub Code:3341902 Sub: TE-I Date: 29/01/2019 Time: 10:30 AM to 11:30 AM Marks: 20 Note: All questions are compulsory. 1 Define any 4 from the following terms:

1. Latent heat of vaporization 2.saturation temperature 3. Degree of superheat 4. Boiler 5. dry fraction of steam

4

2 What are the methods of measurement of dryness fraction of steam? Explain any one out of them in detail.

OR Define triple point and Draw the triple point diagram (phase diagram) of H2O.

3

3 With the help of steam table find the values of entropy of water, entropy of evaporation and entropy of dry saturated steam at 5 bar, 8 bar, 12 bar, 15 bar and 20 bar, 250C, 800c.

OR Give the classification of boiler.(at list 6 classification)

3

4 Explain Babcock-Wilcox boiler with neat sketch. OR

Explain Cochran boiler with neat sketch.

5

5 Write down the essential requirement of good Boiler. OR

Write the important terms of steam boilers.

3

6 2 kg of steam at 10 bar and 0.9 dryness fraction is converted into superheated steam with 500C as degree of super heat. Find the change of enthalpy. Given Cp =2.0 kJ/kg K.

2

Laxmi Institute of Technology, Sarigam Approved by AICTE, New Delhi; Affiliated to Gujarat Technological University, Ahmedabad

Academic Year 2017-18 Centre Code: 691 Examination : Mid Semester Examination- II Branch: MECHANICAL Semester: 4th Sub Code:3341902 Sub: TE-1 Date: 03/04/2018 Time: 10:30 AM to 11:30 AM Marks: 20 Note: 1 Define any 3 from the following terms:

1. Prime movers 2. Nozzle 3. Air compressor 4. Nozzle efficiency 5. Free Air Delivered (FAD)

3

2 Give the detail classification of Steam Turbine. OR

Give the detail classification of Compressor.

3

3 Derive the expression for the exit velocity of fluid from the nozzle. OR

Derive the expression for discharge through nozzle.

4

4 List out the types of compounding of steam turbine. Explain the velocity compounding. OR

Derive the expression for work done in case of two-stage reciprocating air compressor with intercooling. Draw the neat sketch of P-V for two- stage compression.

4

5 During a boiler trial following data are available:- Coal used= 500 kg/hr Mass of dry flue gas= 22.5 kg/kg of coal Calorific value of coal= 31000 kj/kg-k Flue gas temp= 310 degree c Cp of flue gas= 1.008 kj/kg-K Cp of steam= 1.89 kj/kg-K Boiler room temp= 18 degree c Feed water temp= 79 degree c Dry saturated steam generated= 4700 kg/hr Steam pressure= 12 bar Atmospheric pressure= 1 bar Prepare the heat balance sheet / kg of coal burnt.

OR The following observations are available from the boiler trail: Feed water temperature = 22 degree C Average pressure of boiler = 10 bar Dryness fraction of steam = 0.85 Coal used = 250 kg/hr Steam generated = 2500 kg/hr Calorific value of coal = 28000 kj/kg. Calculate :- 1) equivalent evaporation, 2) boiler efficiency, 3) boiler power

4

6 Steam nozzle is supplied with steam for increasing the speed. the inlet and exit condition of steam are as under: INLET:- h1 = 3000 kj/kg , V1 = 60 m/s EXIT: - h2 = 2600 kj/kg, V2 =? Calculate:- 1) exit velocity of steam , 2) mass flow rate if inlet area = 0.1 m2. Specific volume of steam at inlet = 0.182 m3/kg

2

1/3

Seat No.: ________ Enrolment No.______________

GUJARAT TECHNOLOGICAL UNIVERSITY DIPLOMA ENGINEERING – SEMESTER – IV • EXAMINATION – WINTER - 2016

Subject Code: 3341902 Date:19 -11 - 2016

Subject Name: THERMAL ENGINEERING I

Time: 02:30 PM TO 05:00 PM Total Marks: 70 Instructions:

1. Attempt all questions.

2. Make Suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.

4. Use of programmable & Communication aids are strictly prohibited.

5. Use of only simple calculator is permitted in Mathematics.

6. English version is authentic.

Q.1 Answer any seven out of ten. દશમ ાંથી કોઇપણ સ તન જવ બ આપો. 14

1. Define 1] sensible heat 2] dryness fraction

૧. વ્ય ખ્ય આપો. ૧] સેંસસબલ હીટ ૨] ડ્ર ઇનેસ ફે્રકશન

2. State four factors affecting the selection of a boiler.

૨. બોઇલર પસાંદગીમ અસર કરત ચ ર પરરબળો જણ વો.

3. State the function of economizer and fusible plug.

૩. ઇકોનોમ ઇઝર અને ફ્યસુસબલ પ્લગન ક યય જણ વો.


૪. સ્ટીમ પ્ર ઇમ – મવૂસયનો કાંસેપ્ટ લખો.


૫. સ્ટીમ પ વર પ્લ ાંટમ કાંડેનસર અને કૂલીંગ ટ વરનુાં ક યય જણ વો.

6. Define the following terms with reference to air compressor. 1] isothermal

efficiency 2] free air delivered

૬. એર કોમ્પ્પે્રસરન સાંદર્યમ ાં નીચેન પદોની વ્ય ખ્ય આપો. ૧] આઇસોથમયલ ક્ષમત ૨] ફ્રી એર ડીલલવડય


૭. કોમ્પ્પે્રસ્ડ હવ ન ચ ર ઉપયોગો લખો.

8. Define 1] conduction 2]convection

૮. વ્ય ખ્ય આપો. ૧] કાંડકશન ૨]કાંવેકશન

9. State four properties of good insulators.

૯. સ ર ઇંસ્યલેુટસયન ચ ર ગણુધમો લખો.

10. State the method of measurement of dryness fraction.

૧૦. ડ્ર યનેસ ફે્રકશન મ પવ ની રીત જણ વો.

Q.2 (a) What is throttling? Draw throttling process on P-V and T-S diagram. 03

પ્રશ્ન. ર (અ) થ્રોટલીંગ એટલે શુાં? થ્રોટલીંગ પ્રરિય P-V અને T-S ડ ય ગ્ર મ પર દોરો. ૦૩

OR

(a) Explain method of determining dryness fraction by throttling calorimeter with

neat sketch. 03

(અ) સ્વચ્છ આકૃસતની મદદથી થ્રોટલીંગ કેલોરીસમટરથી ડ્ર યનેસ ફે્રકશન શોધવ ની રીત સમજાવો.

૦૩

(b) Find out enthalpy and entropy of steam having pressure of 20 bar and dryness

fraction 0.85. Use mollier chart and also draw sketch. 03

2/3

(બ) જેનુાં દબ ણ ૨૦ બ ર અને ડ્ર યનેસ ફે્રકશન ૦.૮૫ છે તેવી સ્ટીમની એંથ લ્પી અને એંટ્રોપી શોધો. મોલીયર ચ ટયનો ઉપયોગ કરો અને સ્કેચ દોરો.

૦૩

OR

(b) Explain formation of steam and its various phases. 03

(બ) સ્ટીમ ફ્ોમેશન અને તેન જુદ જુદ ફે્ઝ્સ સમજાવો. ૦૩

(c) Explain Cochran boiler with neat sketch. 04

(ક) સ્વચ્છ આકૃસતની મદદથી કોચર ણ બોઇલર સમજાવો. ૦૪

OR

(c) Differentiate between boiler mountings and accessories. 04

(ક) બોઇલર મ ઉંટીંગ્સ અને બોઇલર એસેસરીઝ્સ વચ્ચે તફ્ વત આપો. ૦૪

(d) Differentiate between induced draft and forced draft fan with reference to

boiler. 04

(ડ) બોઇલરન સાંદર્યમ ાં ઇંડયસુ્ડ ડ્ર ફ્ટ અને ફ્ોસ્ડય ડ્ર ફ્ટ ફે્ન વચ્ચે તફ્ વત આપો. ૦૪

OR

(d) State the main safety precautions to be taken in boiler house as per IBR. 04

(ડ) આઇબીઆર મજુબ બોઇલર હ ઉસ પર લેવ પડત સલ મતીન મખુ્ય પરરબળો જણ વો.

૦૪

Q.3 (a) Differentiate between jet condenser and surface condenser. 03

પ્રશ્ન. 3 (અ) જેટ કાંડેનસર અને સફે્સ કાંડેનસર વચ્ચે તફ્ વત આપો. ૦૩

OR

(a) State the advantages of condensers in steam power plant. 03

(અ) સ્ટીમ પ વર પ્લ ાંટમ ાં કાંડેનસરન ફ્ યદ ઓ જણ વો. ૦૩

(b) Classify cooling towers and mention why they are used? 03

(બ) કુલીંગ ટ વરનુાં વગીકરણ કરો અને તેઓન ઉપયોગ પ છળનુાં ક રણ જણ વો. ૦૩

OR

(b) Explain natural draught hyperbolic cooling towers with neat sketch. 03

(બ) સ્વચ્છ આકૃસતની મદદથી નેચરલ ડ્રોટ હ ઇપરબોલીક કુલીંગ ટ વર સમજાવો. ૦૩

© Derive the condition of maximum discharge through steam nozzle.

(ક)સ્ટીમ નોઝલમ ાંથી મહત્તમ ડીસ્ચ ર્જ મ ટેની શરત ત રવો. OR

04

(c) Dry and saturated steam at 12 bar pressure enters the nozzle. The pressure is

reduced to 1.5 bar. If the expansion if frictionless adiabatic then find out the

final velocity.

04

(ક) એક નોઝલમ ાં સકૂી અને સેચ્યરેુટેડ સ્ટીમ ૧૨ બ ર દબ ણે પ્રવેશે છે. પછી દબ ણ ૧.૫ બ ર સધુી ઘટે છે. જો સવસ્તરણ ઘર્યણરહીત એડીય બેરટક હોય તો અંસતમ ઝડપ શોધો.

૦૪

(d) Differentiate between impulse and reaction turbine. 04

(ડ) ઇમ્પ્પલ્સ અને રીએક્શન ટબ યઇન વચ્ચે તફ્ વત આપો. ૦૪

OR

(d) State the necessity of compounding the steam turbine and explain velocity

compounding. 04

(ડ) સ્ટીમ ટબ યઇનનુાં કાંપ ઉડીંગની જરૂરરય ત જણ વો અને વેલોસસટી કાંપ ઉડીંગ ૦૪

3/3

સમજાવો.

Q.4 (a) Differentiate between reciprocating and rotary compressor. 03

પ્રશ્ન. ૪ (અ) રેસીપ્રોકેટીંગ અને રોટરી કોમ્પ્પે્રસર વચ્ચે તફ્ વત આપો. ૦૩

OR

(a) Explain the need of multistage compression and state its advantages. 03

(અ) મલ્લ્ટસ્ટેજ કોમ્પ્પે્રશનની જરૂરરય ત સમજાવો અને તેન ફ્ યદ લખો. ૦૩

(b) A compressor compresses the air from 1 bar to absolute to 7 bar absolute

pressure. The clearance volume is 2130 cm3

/sec. The compression and

expansion is according to PVn= C. If the volumetric efficiency of compressor

is 85%, find out the stroke volume. Take n = 1.3.

04

(બ) એક કોમ્પ્પે્રશર ૧ બ ર એબસોલ્યટુ દબ ણથી ૭ બ ર એબસોલ્યટુ દબ ણ સધુી હવ ને કોમ્પ્પે્રસ કરે છે. ક્લીરયાંસ વોલ્યમુ 2130 cm

3/sec છે. કોમ્પ્પે્રશન અને

એક્ષપ ાંશન PVn= C મજુબ છે. જો કોમ્પ્પે્રશરની વોલ્યમેુટ્રીક ક્ષમત ૮૫% હોય તો

સ્ટ્રોક વોલ્યમુ શોધો. n = 1.3 લો.

૦૪

OR

(b) Draw neat sketch of a single stage reciprocating compressor and explain its

working.

04

(બ) સીંગલ સ્ટેજ રેસીપ્રોકેટીંગ કોમ્પ્પે્રશરની સ્વચ્છ આકૃસત દોરો અને તેન ુાં વરકિંગ સમજાવો.

૦૪

(c) Define the following terms. 1] thermal conductivity 2] absorptivity 3]

reflectivity 4] emissivity 5] black body 6] emissive power 7] laminar flow

07

(ક) નીચેન પદોની વ્ય ખ્ય આપો. ૧] થમયલ કાંડક્ટીસવટી ૨] એબ્સોપ્ટીસવટી ૩] રીફ્લેકટીસવટી ૪] ઇમીસસસવટી ૫] બ્લેક બોડી ૬] ઇમીસસવ પ વર ૭] લેમીન ર ફ્લો

૦૭

Q.5 (a) A boiler is generating 10 kg of steam/kg of coal. The calorific value of the

coal is 35,280 kJ/Kg. The heat content of steam is 2835 kJ/Kg and feed water

temperature is 450C. Calculate 1] equivalent evaporation 2] thermal efficiency

04

પ્રશ્ન. ૫ (અ) એક બોઇલર કોલન પ્રસત રકલો ૧૦ રકલોગ્ર મ સ્ટીમનુાં ઉત્પ દન કરે છે. કોલનુાં કેલોરરક વેલ્ય ુ35,280 kJ/Kg છે. સ્ટીમ 2835 kJ/Kg ગરમી ધ રણ કરે છે અને ફ્ીડ વોટરનુાં ત પમ ન 450

C છે. તો ૧] ઇક્વીવેલેંટ ઇવપોરેશન ૨] થમયલ ક્ષમત ની ગણત્રી કરો.

૦૪

(b) State the types of rotary air compressor and explain any one type of air

compressor. 04

(બ) એર કોમ્પ્પે્રસરન પ્રક ર લખો અને કોઇ એક પ્રક રનુાં એર કોમ્પ્પે્રસર સમજાવો. ૦૪

© State the types of heat exchangers. Describe any one type of heat exchanger

with sketch.

03

(ક) હીટ એક્ષચેંજેસયન પ્રક ર લખો. કોઇપણ એક પ્રક રનુાં હીટ એક્ષચેંજેસય આકૃસત સ થે વણયવો.

૦૩

(d) State the applications of steam nozzles. 03

(ડ) સ્ટીમ નોઝલ્સન ઉપયોગો જણ વો. ૦૩

1/3




































OR


neat sketch. 03


૦૩



2/3


૦૩

OR





OR




boiler. 04


OR



૦૪



OR





OR





04



final velocity.

04


૦૪



OR


compounding. 04


3/3

સમજાવો.



OR








04





૦૪

OR


working.

04


૦૪



07


૦૭




04



૦૪


compressor. 04



with sketch.

03


૦૩



1/3




































OR


neat sketch. 03


૦૩



2/3


૦૩

OR





OR




boiler. 04


OR



૦૪



OR





OR





04



final velocity.

04


૦૪



OR


compounding. 04


3/3

સમજાવો.



OR








04





૦૪

OR


working.

04


૦૪



07


૦૭




04



૦૪


compressor. 04



with sketch.

03


૦૩



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