Sample Copy. Not For Distribution. · 5.4 Terms associated with steam formation. 95 5.5 Triple point 98 5.6 Dryness Fraction of Saturated Steam (x or q) 99 5.7 Methods of determination

Sample Copy. Not For Distribution.

i

A Text Book of

Thermal and Power Engineering

For Polytechnic Students Only


ii

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________________________________________________________________

© Copyright, 2018, Ashutosh Kumar

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form by any means, electronic, mechanical, magnetic, optical, chemical, manual, photocopying, recording or otherwise, without the prior written consent of its writer.

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Printed in India


iii

A Text Book of Thermal and Power

Engineering For Polytechnic Students Only

Ashutosh Kumar

EDUCREATION PUBLISHING (Since 2011)

www.educreation.in


iv


v

About Book The subject of thermal and power engineering is core subject of

engineering. The subject has a wide scope and its application is

extensive. The Text book focuses the need of first level text

book for diploma level students and professional reference for practicing engineer. one of the salient features of this book is

written in simple and lucid language with conceptual clarity.

The present Text book endeavors to provide relevant theory

and principal of thermodynamics and its application.It is our hope that this book will be a immense value to the technical

teachers, students as well as professional in the field. we look

forward to receiving invaluable suggestions from the users and

experts in the field. This text book could be improved further on the basis of constructive suggestion.

About Author

Author currently working as lecturer in Xavier institute of

polytechnic and technology, Namkum. he has obtained his

diploma from Birla institute of technology Mesra, Bachelor of engineering from RTM nagpur university, Nagpur and Master's

degree from RGPV Bhopal. He has several years of teaching

experience in different university and industrial experiences. He

has published several research paper in international journal and presented the research paper in international conference.

Presently he is actively engaged in writing books.


vi

Dedicated to

My wife Tripti


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Content List

Sr. No. Content Page

1. Source Of Energy 1

1.1 Brief Classification Of Energy Sources 1

1.2 Fossil fuels: 2

1.3 Solar Thermal Collectors: 3

1.4 Photovoltaics cell : 7

1.5 Photo-Voltaic Electric Conversion Process.

8

1.6 Wind Energy 9

1.7 Tidal 10

1.8 Geo Thermal Energy 12

1.9 Bio Gas 13

1.10 Biomass 15

1.11 Biodiesel Production 17

1.12 Hydroelectric Power 19

1.13 Nuclear Power 22

1.14 Fuel Cells 23

Review Question 24

2. Basic Concept Of Thermodynamics 25

2.1 Definition And Importance Of

Thermodynamics

25

2.2 System (Macroscopic Vs Microscopic

Point Of View)

25

2.3 Thermodynamic System, Surroundings And Boundary

26

2.4 State,Path, Process And Cycle 28

2.5 Thermodynamics reversible and 29


viii

irreversible processes

2.6 Forms Of Energy

32

2.7 Non Flow Work Or Closed Sytem Work 32

2.8 Point Function And Path Function 33

2.9 Important Points With Respect To Heat

Transfer And Work Done

34

2.10 Properties Of System, Intensive And Extensive Properties

34

2.11 Temperature , Absolute Temperature

And Pressure

35

2.12 Thermal, Mechanical, Chemical And Thermodynamic Equilibrium

37

2.13 Zeroth Law Of Thermodynamic 37

2.14 Quasi-Static Process, Work Done

During Quasi-Static Process.

38

2.15 Concept Of Ideal Gas 39

2.16 Basic Gas Law 39

2.16.1 Boyle‘s law 39

2.16.2 Charle‘s Law 39

2.16.3 Gay –Lussac Law 39

2.17 General Gas Equation 40

2.18 Characteristics Gas Equation : 40

2.19 Avagadro‘s Law 40

2.20 Universal Gas Constant (Molar Constant)

41

2.21 Specific heat (C ) 42

2.21.1Specific heat constant pressure (Cp) 42

2.21.2 Specific heat constant volume (Cv) 42

2.22 Relations between specific heats

(Cp_& Cv)

42

2.23 Cp Is Greater Than Cv Or Cp>Cv 43

Review Problem 43

Review Question 46


ix

3. First law of Thermodynamics 48

3.1 Heat Reservoir, Heat Source & Heat

Sink

48

3.2 First law of Thermodynamics 49

3.2.1 First Law for a closed system

undergoing a Cycle:

49

3.2.2 First Law for a closed system undergoing a change of state

51

3.2.3 First Law for an Isolated system 52

3.3 Perpetual Motion Machine Of First

Kind-PMM-1

52

3.4 Steady Flow Energy Equation (SFEE) 54

3.4.1 Application Of SFEE To Various Units 56

3.5 Enthalpy 57

3.6 Non- flow or closed system work for various process

57

Review problem 59

Review Question 69

Multiple Choice Question 69

4. Second law of Thermodynamics 71

4.1 Limitations of First law. 71

4.2 Statement of Second Law-Kelvin

planck‘s and Clausius Statements

71

4.3 Perpetual Motion Machine Of 2nd Kind. 74

4.4 Equivalence of Kelvin Planck and

clausius statements.

74

4.5 Carnot Theorem 76

4.6 Clausius Inequlity 77

4.7 Concept of Entropy 79

4.7.1 Principal of Increase of Entropy 79

4.7.2 T-S and H-S diagrams computation

of change in entropy.

81

4.7.3 Enthalpy-entropy diagram, h-s

diagram

81


x

Review Problem 82

Review Question 85


5. Two Phase System 88

5.1 Pure Substance and Phase 88

5.2 Homogeneous and Heterogeneous System

89

5.3 Steam formation and its

representation on the enthalpy plane,(

Properties changes)

89

5.3.1 Temperature-Enthalpy Diagram T-H

Diagram

89

5.3.2 P-v diagram of pure substance 91

5.3.3 T-s diagram can be drawn for a pure substance.

93

5.3.4 h-s diagram of water 94

5.4 Terms associated with steam

formation.

95

5.5 Triple point 98

5.6 Dryness Fraction of Saturated Steam

(x or q)

99

5.7 Methods of determination of dryness

fraction of steam

99

5.7.1 Separating Calorimeter 99

5.7.2 Throttling Calorimeter 101

5.7.3 Separating & Throttling Calorimeter 102

5.8 Steam Tables 104

5.9 Rankine cycle 107

5.10 Modified Rankine cycle 109

Review Problem 110

Review Question 113


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6. Steam Generators 114

6.1 Steam Generators 114

6.1.1 Classification Of Boiler 114

6.1.2 Difference Between Water Tube And

Fire Tube Boiler

115

6.1.3 Merits And Demerits Of Water Tube

Boilers Over Fire Tube Boilers Merits

117

6.1.4 Requirements Of A Good Boiler 118

6.2 Mountings 118

6.3 Accessories 120

6.4 Locomotive Boiler 120

6.5 Cochran Boiler 122

6.6 Lancashire Boiler 124

6.7 Babcox Wilcox Water Tube Boiler 126

6.8 Stirling Bent Tube Boiler 128

6.9 High Pressure Boilers 130

6.9.1 La mont Boiler 130

6.9.2 Benson Boiler 131

6.9.3 Loeffler Boiler 133

6.10 Boiler Draught 134

6.11 Classification Of Boiler Draught 135

6.11.1 Induced draught 135

6.11.2 Forced Draught 136

6.11.3 Balanced Draught 136

6.12 Comparison between Forced Draught

and induced Draught

137

Review Question 138

7. Flow through Nozzle 139

7.1 Nozzle 139

7.1.1Types of steam nozzle 139

7.2 Concept of MACH number 139

7.2.1 Importance of MACH number 140

7.3 Application of steam Nozzle 140


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7.4 Continuity Equation 140

7.5 Expression for Critical Pressure ratio 141

Review Question 142

8. Steam Turbine 143

8.1 Steam turbine 143

8.2 Classification of Steam turbine 144

8.2.1 Impulse Turbine 144

8.2.2 Reaction Turbine 145

8.2.3 Difference Between Impulse And

Reaction Turbine.

146

8.3 Compounding of steam turbine,

velocity diagram (introductory) and its

use.

146

8.4 Regenerative feed heating 150

8.5 Governing of steam turbine 152

Review Question 154

9. Condenser 155

9.1 Condenser 155

9.1.1 Function of a condenser 155

9.1.2 Advantage of Condensing over Non

condensing steam engine

155

9.1.3 Advantage of a condenser in a Steam Power Plant

156

9.2 Dalton‘s Law Of Partial Pressure 157

9.3 Classification of Condenser 158

9.4 Requirements Of A Modern Surface Condenser

164

9.5 Sources of air in condenser 165

9.5.1 Effects of Air leakage in Condenser 165

9.6 Vaccum efficiency 166

9.7 Condenser Efficiency 166

Review Question 167


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10. Cooling Tower 168

10.1 Cooling Tower 168

10.2 Types Of Cooling Tower 168

10.2.1 Natural Draught Cooling Towers

(NDCT)

169

10.2.2 Forced Draught Cooling Tower (FDCT)

169

10.2.3 Induced Draught Cooling Tower

(IDCT)

170

10.3 Performance Of Cooling Tower 174

Review Question 176

11. Heat Transfer 177

11.1Heat Transfer 177

11.1.1 Modes of heat transfer 177

11.2 Fourier‘s Law of Heat Conduction 180

11.3 Newton‘s Law of Cooling 181

11.4 Thermal Resistance (Rth) 182

11.5 Expression for determination of heat transfer across a flat plate

182

11.6 Heat Transfer Across A Composite

Wall

183

11.7 Types Of Heat Exchanger Are As Follows.

185

11.8 Absorption ,Reflection And

Transmission Of Radiation

186

11.9 Stefan boltzman law 187

Review Question 187

12. Thermodynamic Cycles 189

12.1.Gas Power cycles 189

12.1.1 Carnot Cycle 189

12.1.2 Stirling Cycle 191

12.2 Air-Standard cycles-definition and its 192


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purpose

12.2.1 Otto Cycle 193

12.2.2 Diesel Engine 196

12.2.3 Comparison of the Otto and the

Diesel Cycle

198

12.2.4 Brayton Cycle 201

Review Problem 202

Review Question 204

13. Internal Combustion engine 205

13.1 Introduction 205

13.2 Classification of I.C. Engines 206

13.3 Comparison Of 2 Stroke And 4 Stroke

Engine

206

13.4 Comparision Of Si & Ci Engines 208

13.5 Two Stroke Petrol Engine 208

13.5.1 Actual Indicator Diagram of Two

Stroke Petrol Engine

209

13.5.2 Actual Valve Timing Diagram of

Two Stroke Petrol Engine

210

13.6 Two Stroke Diesel Engine 210

13.6.1 Actual Indicator Diagram of Two

Stroke diesel Engine

210

13.6.2 Actual Valve Timing Diagram of Two Stroke diesel Engine

211

13.7 Four Stroke Petrol Engine 211

13.7.1 Working of Four Stroke Petrol

Engine

211

13.7.2Theoretical and actual Indicator

diagram Of Four Stroke Petrol Engine

212

13.7.3 Valve timing Diagram Of Four

Stroke Petrol Engine

213

13.8 Four Stroke diesel Engine 213

13.8.1 Indicator Diagram Of 4 Stroke

Diesel Engine

215

13.8.2 Valve Timing Diagram Of 4 Stroke 215


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Diesel Engine

13.9 Combustion in S.I Engine 215

13.9.1 Theories Of Combustion In S.I Engine

216

13.9.2 Three Stage Of Combustion In S.I

Engine

217

13.10 Combustion in C.I Engine 218

13.10.1 Stages of Combustion in C.I

Engine

219

13.11 Scavenging 220

13.12 Preignition 220

13.13 Detonation 220

13.14 Supercharging 220

13.15 Turbo charging 220

13.16 Simple Carburetor 221

13.17 M.P.F.I (Multi Point Fuel Injection

System)

222

13.18 Fuel Injection Pump 223

13.19 I.C. engine components and their

function

223

13.20 .Governor 230

13.20.1 Governing of I.C. engines. 230

13.21 Lubrication of I.C engine 232

13.21.1 Purpose of lubrication 232

13.21.2 Properties of good lubricant 232

13.21.3 Types Of Lubricants 233

Review Problem 234


14. I.C Engine Testing And Pollution

Control

241

14.1 Engine terminology: Stroke, bore,

piston speed, mep,compression & cut-off ratio etc.

241

14.2 Engine Testing - I.P., B.P 242


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14.3 Efficiency of I.C engine, 244

14.4 Heat Balance sheet. 245

14.5 Morse Test, 246

14.6 Motoring test 247

14.7 Fuel 248

14.7.1 Classification of fuels 248

14.8 Lubricating additives 249

14.9 Pollution Control 250

Review Question

Multiple Choice Queston

251

252

15. Air Compresser 253

15.1 Air Compressor 253

15.2 Classification of compressors and

their field of application

253

15.2.1 Single Stage Reciprocating Air

Compressor

254

15.2.2 Double acting Reciprocating Air

Compressor

259

15.2.3 Double Stage Reciprocating Air Compressor

259

15.2.4 Multi-Stage Air Compressor 260

15.3 Efficiencies of reciprocating air

compressor

262

15.4 Rotary Air Compressor 263

15.4.1 Helical Screw Compressor 263

15.4.2 Sliding Vane Compressor 264

15.4.3 Lobe or Roots Blower Compressor 264

15.5 Non Positive Displacement or

Dynamic Air Compressors

265

15.5.1 Centrifugal Air Compressor 265

15.5.2 Axial Flow Air Compressor 266

15.6 Purification of air 267

15.7 Methods Of Energy Saving In Air

Compressor

267


xvii

Review Problem 269

Review Question 271

16. Gas Turbine And Jet Propulsion 272


16.2 Classification of gas turbine. 272

16.3 Application Of Gas Turbine 273

16.4 Constant Volume Or Atkinson Cycle 273

16.5 Constant pressure or continous

combustion gas turbine (Joule or brayton

cycle)

274

16.6 Method to improve the efficiency of

the gas turbine

276

16.6.1 Open cycle gas turbine with

Intercooling

276

16.6.2 Open Cycle Gas Turbine With

Reheating

277

16.6.3 Open Cycle Gas Turbine With

Regeneration

278

16.7 Closed cycle and open cycle gas turbine and their comparision

279

16.8 Jet Propulsion 281

16.8.1 Principal of turbojet 281

16.8.2 .Principal of turbo prop or turbo propeller

281

16.8.3 Principal of Ram Jet 282

16.9 Rocket propulsion 282

16.10 Propellants 283

16.10.1 Solid propellants 283

16.10.2 Liquid Propellant Rocket. 284

Review Question

Multiple Choice Question

285

286

17. Refrigeration and Air- Conditioning 287



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17.2 Coefficient of Performance 287

17.2.1 COP of Heat Pump and refrigerator, 287

17.3 Tonnes of Refrigeration. 289

17.4 Reversed Carnot Cycle 289

17.5 Bell Coleman Cycle:(Reversed

Brayton Cycle or Joule cycle)

290

17.6 Vapour compression refrigeration cycle

293

17.6.1 Output Of Compressor Is Dry

Saturated

294

17.6.2 Output of condenser Undercooling 294

17.6.3 Input of compressor is superheated 295

17.7 Simple Vapour Absorption

Refrigeration System

296

17.8 Applications of vapour absorption system

297

17.8.1 Water cooler 298

17.8.2 Domestic Refrigerator 298

17.8.3 Ice plant 300

17.8.4 Cold storage 302

17.9 Air conditioning 302

17.10 Application of air conditioning 303

17.10.1 Window air conditioner. 303

17.11 Psychrometry 305

17.11.1 Psychrometric Properties of air 305

17.12 Dalton‘s Law Of Partial Pressure 307

17.13 Psychrometric chart & processes 309

Review Problem 311

Review Question

Multiple Choice Question

316

317


Source of Energy 1

A Text Book of Thermal and Power Engineering

Chapter -1

Source of Energy ______________________________________________________

1.1 Brief Classification of Energy Sources

There are mainly two sources of energy

1. Renewable Sources of Energy(Non-conventional Sources of

Energy)

2. Non-Renewable Sources of Energy( Conventional Sources of Energy)

Renewable Sources of Energy(Non-conventional Sources

of Energy)

Renewable energy is the energy that is collected from

renewable resources, which are naturally replenished on a

human timescale, such as sunlight, wind, rain, tides, waves

and geothermal heat.Renewal energy sources include both

―direct‖ solar radiation intercepted by collectors (e.g. solar and flat-plate thermal cells) and indirect solar energy such as wind,

hydropower, ocean energy and biomass resources that can be

managed in sustainable manner

Renewable energy often provides energy in four important areas:

1) Electricity generation

2) Air and water heating/cooling

3) Transportation

4) Rural (off grid) energy services

Non-Renewable Sources of Energy (Conventional

Sources of Energy)

These resources are finite and exhaustible. Once consumed, these sources cannot be replaced by others. It does not form or


Source of Energy 2

A Text Book of Thermal and Power Engineering

replenish in a short period of time. Major non-renewable energy

sources are:,fossil fuel,nuclear fossil fuel (Uranium & Thorium)

1.2 Fossil Fuels

Fossil fuel is an invaluable source of energy produced due to

chemical changes taking place in the plants and animals that have been buried deep in the earth‟s crust for many million

years in the absence of oxygen, Fossil fuels like Coal,

Petroleum and Natural Gas((LPG,CNG) are formed in this

way and these are conventional sources of energy. All fossil fuel are non-renewable, but not all non-renewable energy sources

are fossil fuels.

LPG (Liquefied Petroleum Gas)

LPG is a mixture of propen & butane liquefied at 15 and a

pressure of 1.7 to 7.5 bar. and widely used fuel in homes. Petroleum gas is a constituent obtained when petroleum is

subjected to fractional distillation. If high pressure is applied to

this gas it will be liquefied. This liquid is LPG (Liquefied

Petroleum Gas). This is filled in strong cylinders and distributed.

The main constituent of this is Butane but small quantities of Ethane and Propane are also found.

Gases in LPG are odorless. When it leaks, it fills the whole

room. if an electric switch is switched on or a matchstick is

struck A Big fire or explosion will take place. Therefore to detect the leakage of the LPG another gas, Ethyl

merchantman, having a special smell is mixed with it. When

the gas cylinder is opened smell of this is sometimes felt. If this

smell is felt never try to light the match or to operate electrical appliances & doors and windows must be opened to check

whether there is any leak in the cylinder or not. When not in

use it is better to have the valve of the cylinder to be in the

closed postion.

CNG (Compressed Natural Gas)

It is compressed natural gas, made by compressing natural gas

to a less than 1% of its volume at a standard atmospheric

pressure considering mostly of methane. It is readily available alternate to gasoline.CNG is odourless, colorless & testless.It is

drawn from domestically drilled natural gas wells or in

conjunction with crude oil production..Natural gas powers more


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Sample Copy. Not For Distribution. · 5.4 Terms associated with steam formation. 95 5.5 Triple point 98 5.6 Dryness Fraction of Saturated Steam (x or q) 99 5.7 Methods of determination

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