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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Sample Copy. Not For Distribution.
i
A Text Book of
Thermal and Power Engineering
For Polytechnic Students Only
Sample Copy. Not For Distribution.
ii
Publishing-in-support-of,
EDUCREATION PUBLISHING
RZ 94, Sector - 6, Dwarka, New Delhi - 110075 Shubham Vihar, Mangla, Bilaspur, Chhattisgarh - 495001
Website: www.educreation.in
________________________________________________________________
© 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.
The author of the book has taken all possible care to ensure that the contents of the book do not violate any existing copyright or other intellectual property right of any manner what’sover. In the event, the author has been unable to track any source and if any copyright has been inadvertently infringed, the fact may be brought to the notice of the author or publisher in writing for corrective action.
ISBN: 978-1-5457-1349-5
Price: ` 415.00
The opinions/ contents expressed in this book are solely of the authors and do not represent the opinions/ standings/ thoughts of Educreation or the Editors . The book is released by using the services of self-publishing house.
Printed in India
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A Text Book of Thermal and Power
Engineering For Polytechnic Students Only
Ashutosh Kumar
EDUCREATION PUBLISHING (Since 2011)
www.educreation.in
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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.
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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
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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
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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
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x
Review Problem 82
Review Question 85
Multiple Choice Question 86
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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xv
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
Multiple Choice Question 239
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
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xvii
Review Problem 269
Review Question 271
16. Gas Turbine And Jet Propulsion 272
16.1 Introduction 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
17.1 Introduction 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
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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
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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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