Principles_of_Solar_Gas_Turbines_

Green Energy and Technology

Amos Madhlopa

Principles
of Solar Gas
Turbines for
Electricity
Generation


Green Energy and Technology


More information about this series at />

Amos Madhlopa

Principles of Solar Gas
Turbines for Electricity
Generation

123


Amos Madhlopa
Energy Research Centre, Department
of Mechanical Engineering
University of Cape Town
Cape Town
South Africa

ISSN 1865-3529
ISSN 1865-3537 (electronic)
Green Energy and Technology
ISBN 978-3-319-68387-4
ISBN 978-3-319-68388-1 (eBook)
/>Library of Congress Control Number: 2018935877
© Springer International Publishing AG, part of Springer Nature 2018
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Preface

Since the Industrial Revolution in the eighteenth century, fossil fuels have played a

critical role in the global economic advancement. They fuel many technologies,
ranging from motor vehicles to power plants. Nevertheless, environmental degradation is one main concern about their exploitation. It is perceived that emissions
from the consumption of fossil fuels are contributing to global warming. Therefore,
at the Twenty-first Conference of the Parties (COP21) to the United Nations
Framework Convention on Climate Change held in Paris in December 2015, delegates agreed to limit the global temperature rise below 2 K (2°C) above
pre-industrial levels. Achievement of this goal will require significant reduction in
greenhouse gas (GHG) emissions from different sources, including power plants.
Another concern is that fossil fuels occur in finite quantities, implying that they can
be depleted, thereby posing a risk to energy security. On the other hand, renewable
energy resources replenish themselves through natural mechanisms and have
generally low GHG emissions. In this vein, one of the most important renewable
energy resources is solar radiation, which can be converted to electricity by using a
suitable technology.
Conversion of primary energy to electricity requires technologies which usually
come in the form of engines. Heat engines (including gas turbines), predominantly
fuelled by fossil resources, have found wide application in the energy sector. A gas
turbine is an internal combustion engine that traditionally comprises a compressor,
combustion chamber (combustor), and turbine. This engine utilizes air as the
conventional working fluid which is sucked into the compressor and pressurized
before flowing into the combustor where it mixes with fuel and combustion of the
mixture takes place. The hot fluid expands through the turbine section, thereby
developing mechanical power. Concerns about sustainable development are driving
changes in national and international laws and policies that support transition to
renewable energy. These developments are affecting the direction of research on
gas turbine and other technologies. In this connection, solarization of the gas turbine engine is an important option for achieving a sustainable energy mix.

v


vi

Preface

Generally, a gas turbine operates at high turbine inlet temperature (>673 K), and
so concentrated solar radiation is suitable to achieve such temperature levels. The
intensity of direct normal irradiance is a good indicator of the suitability of a site for
exploitation of concentrating solar power (CSP) technologies. Basically, a CSP
power plant comprises a solar field (concentrator and receiver) and a power block.
The concentrator focuses direct (beam) radiation onto the receiver which heats up a
heat transfer fluid flowing through it. Then, the hot fluid is directly or indirectly
used to drive an engine cycle in the power block. The recommended minimum
annual sum of direct normal irradiation for CSP technology to be economically
viable is 2,000 kWhm−2, and many locations within the sunbelt in the world meet
this requirement. It is particularly pleasing to note that the worldwide technical
potential of CSP is estimated at 3,000,000 TWh/year which significantly exceeds
the world electricity consumption level of about 29,000 TWh/year in 2015.
The commonest CSP technologies exploited globally are the linear Fresnel
reflector (LFR), parabolic trough concentrator (PTC), parabolic dish concentrator
(PDC) and solar tower (ST). Studies have shown that the LFR and PTC technologies are capable of attaining temperatures of about 323–573 K and 293–673 K,
respectively, which are lower than those typically required at the inlet to the turbine
section. In contrast, the PDC and ST technologies exhibit high thermodynamic
performance, being reportedly able to reach temperatures of 393–1773 K and 573–
1273 K, respectively, that are suitable for solarization of the gas turbine cycle.
However, at the time of writing this book, most of the operating CSP power plants
in the world were based on the Rankine steam cycle driven by the PTC technology,
followed by the ST. Consequently, research efforts are being directed towards the
solarisation of gas cycles. A solar gas turbine (SGT) is a device in which concentrated solar radiation is used to heat up a gas working fluid before it expands
through the turbine section. Considering the good thermodynamic performance and
technological maturity, the ST technology is a promising candidate for solarization
of gas turbines.

Many studies have examined the SGT technology but there is limited collated
information (in book form) on advances in the various aspects of SGT systems.
This is the first book on solarization of gas turbines and it brings together pieces of
new knowledge on this subject with adequate illustrations and coherent treatment.
The main objective of the book is to provide the reader with principles of solar gas
turbines and a state of the art. The context of solarising gas turbines is presented in
Chap. 1. This chapter also introduces relevant fundamentals of gas turbines, heat
transfer, solar thermal processes and solar gas turbines. Chapters 2 and 3 focus on
fuels and solar radiation, respectively, as heat sources for the SGT engine. The
discussion on fuels includes aspects of emissions, which is important for environmental protection. Various components of a SGT are covered in Chap. 4. It is
observed that the receiver and combustor are critical components in the solarization
process. Based on the heat transfer medium, receivers can be classified into gas,
liquid and solid-particle categories. Gas receivers are capable of attaining high
temperatures (up to 1773 K) and therefore more suitable for exploitation in SGT
systems. Liquid and particle receivers can heat up the working fluid in a SGT only


Preface

vii

via heat exchangers, which would tend to reduce the efficiency of converting solar
energy to useful heat. Receivers can also be classified based on their geometry:
tubular, volumetric and microchannel receivers. Although each category has
advantages and some advantages, tubular and volumetric receivers are emerging to
be in the most advanced stage of development. These receivers can be linked to
combustors in hybrid SGTs. At present, combustors in use are designed for conventional gas turbines. Thus, they cannot just be integrated with solar receivers
without modification. For example, the Mercury 50 gas turbine allows a combustor
inlet air temperature of 923 K. However, the receiver outlet air temperature may
reach temperatures of 1773 K. This challenge is aggravated by the lack of gas

turbines tailor-designed to operate on solar energy. Selected relevant engine cycles
have been presented in Chap. 5. Based on the flow path of the working fluid, gas
turbines can be classified into closed, open and semi-closed cycle systems. In the
closed cycle, the working fluid is indirectly heated, which diminishes the thermal
efficiency of the system. Combustion gases constitute part of the working fluid at
the turbine inlet in an open cycle gas turbine, which boosts the thermodynamic
efficiency of this cycle. In view of this attractive thermal performance, open cycle
gas turbines have found widest application in the electricity industry. However, the
use of CO2 as a working fluid in the supercritical phase is improving the thermodynamic performance of the closed cycle. It is also possible to combine the Brayton
and steam cycles to obtain a combined cycle with a high thermodynamic efficiency
(>50%). Exergy analysis reveals that most of the exergy destruction occurs in the
receiver due to the low rate of conversion of solar radiation to useful heat.
Components of a SGT can be arranged in many different configurations, some of
which are presented in Chap. 6. This flexibility in engine layout is an advantage in
the development of the SGT engine. System design is one important aspect of the
development of the SGT technology. So, Chap. 7 covers principles of gas turbine
design and testing. Even if a SGT performs well thermodynamically, its rate of
diffusion on the market is influenced by the cost of electricity production. In view of
this, the last chapter of this book (Chap. 8) examines the economic performance
of solar gas turbines. Levelized cost of electricity (LCOE) is a common metric for
comparison of the economic performance of power plants. Attractive theoretical
values of LCOE (as low as 0.06 US$/kWh) have been reported for the combined
cycle SGT driven by a solar tower, which compares very well with some reported
findings for coal power plants (0.092–0.095 US$/kWh). It is evident from these
findings that the SGT technology is approaching the commercialization stage of
development.
Cape Town, South Africa

Amos Madhlopa

Acknowledgements

I am very grateful to my wife (Sellina) and our children (Vitumbiko, Thandiwe,
Uchizi and Tawonga) for their love, care and moral support.

ix


Contents

1 Introduction to Solar Gas Turbines . . . . . . . . .
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . .
1.1.1 Energy Resources . . . . . . . . . . . . . .
1.1.2 Energy Conversion . . . . . . . . . . . . .
1.2 Basic Gas Turbine for Electricity Generation
1.3 Heat Transfer . . . . . . . . . . . . . . . . . . . . . . .
1.3.1 Conduction . . . . . . . . . . . . . . . . . . .
1.3.2 Convection . . . . . . . . . . . . . . . . . . .
1.3.3 Radiative Heat Transfer . . . . . . . . . .
1.4 Heat Exchangers . . . . . . . . . . . . . . . . . . . . .
1.5 Solar Thermal Processes . . . . . . . . . . . . . . .
1.5.1 Flat-Plate Collector . . . . . . . . . . . . .
1.5.2 Concentrating Solar Collectors . . . . .
1.6 Solar Gas Turbines . . . . . . . . . . . . . . . . . . .
1.7 Other Applications of Solar Gas Turbines . .
1.7.1 Combined Power and Desalination . .
1.7.2 Cogeneration . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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2 Gas Turbine Fuels and Fuel Systems . . . . . . . .
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Fuel Specifications . . . . . . . . . . . . . . . . . . .
2.2.1 Heating Value . . . . . . . . . . . . . . . . .
2.2.2 Cleanliness of Fuel . . . . . . . . . . . . .
2.2.3 Corrosion and Particulate Deposition
2.2.4 Fuel Availability . . . . . . . . . . . . . . .

2.3 Fossil Fuels . . . . . . . . . . . . . . . . . . . . . . . .
2.3.1 Oil and Gas . . . . . . . . . . . . . . . . . . .
2.3.2 Coal . . . . . . . . . . . . . . . . . . . . . . . .

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xi


xii

Contents

2.4 Biofuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.1 Classification of Biofuels . . . . . . . . . . . . . . . . . . . .
2.4.2 Conversion Pathways for Producing Energy Carriers
from Biomass Raw Materials . . . . . . . . . . . . . . . . .
2.4.3 Exploitation of Biofuels in Gas Turbine Engines . . .
2.5 Nuclear Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Solar Radiation Resource . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Components of Solar Radiation . . . . . . . . . . . . . . . . . . . .
3.2.1 Beam and Diffuse Solar Radiation . . . . . . . . . . . .
3.2.2 Direct Normal Irradiance . . . . . . . . . . . . . . . . . . .

3.3 Sun Position and Direction of Beam Radiation . . . . . . . . .
3.4 Extraterrestrial Radiation and Solar Radiation on Inclined
Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.5 Available Solar Radiation on the Earth’s Surface . . . . . . .
3.6 Attenuation of Solar Radiation When Incident on Opaque
and Transparent Surfaces . . . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Main Components of Solar Gas Turbines . . . . . . . . . .
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2 Solar Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2.1 Parabolic Trough Concentrator . . . . . . . . . .
4.2.2 Linear Fresnel Reflector . . . . . . . . . . . . . . .
4.2.3 Parabolic Dish Concentrator . . . . . . . . . . . .
4.2.4 Solar Tower . . . . . . . . . . . . . . . . . . . . . . .
4.2.5 Mirrors for Solar Concentration . . . . . . . . .
4.2.6 Solar Receivers for Gas Turbines . . . . . . . .
4.3 Enhancing the Capability of Solar Gas Turbines . . .
4.3.1 System Hybridization . . . . . . . . . . . . . . . . .
4.3.2 Thermal Storage . . . . . . . . . . . . . . . . . . . .
4.4 Compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.5 Combustor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.5.1 Types of Combustors . . . . . . . . . . . . . . . . .
4.5.2 Requirements for Operation . . . . . . . . . . . .
4.5.3 Gas Turbine Emissions . . . . . . . . . . . . . . .
4.5.4 Some Techniques for Emissions Reductions
in Gas Turbines . . . . . . . . . . . . . . . . . . . . .
4.6 Turbine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.6.1 Types Turbines . . . . . . . . . . . . . . . . . . . . .
4.6.2 Turbine Blade Cooling . . . . . . . . . . . . . . . .
4.7 Basic Electric Generator . . . . . . . . . . . . . . . . . . . .

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92


Contents

4.7.1 Electric-Field Generators . . . . . . .

4.7.2 Magnetic Field Induction . . . . . . .
4.7.3 Frequency of Induced AC Voltage
4.8 Control System . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . .

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5 Thermodynamic Cycles of Solar Gas Turbines . . . . . . . . . . . . .
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2 Carnot Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3 Rankine Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.4 Brayton Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.4.1 Solar-Only Closed Cycle Solar Gas Turbine . . . . . . .
5.4.2 Hybrid Closed Cycle Solar Gas Turbine . . . . . . . . . .
5.4.3 Solar-Only Open Cycle Gas Turbine . . . . . . . . . . . . .
5.4.4 Hybrid Open Cycle Solar Gas Turbine . . . . . . . . . . .
5.4.5 Semi-closed Cycle Solar Gas Turbine . . . . . . . . . . . .
5.5 Combined Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.5.1 Combined Cycle with Closed Topping Brayton Cycle
5.5.2 Combined Cycle with Open Topping Brayton Cycle .
5.6 Exergy Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.6.1 Exergy of Matter Streams . . . . . . . . . . . . . . . . . . . .
5.6.2 Exergy of Non-matter Streams . . . . . . . . . . . . . . . . .
5.7 Influential Factors of Solar Gas Turbine Performance . . . . . .

5.7.1 Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.7.2 Fuel Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.7.3 Air Temperature and Site Altitude . . . . . . . . . . . . . .
5.7.4 Humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.7.5 Inlet and Exhaust Pressure Losses . . . . . . . . . . . . . .
5.7.6 Air Extraction from Compressor . . . . . . . . . . . . . . . .
5.7.7 Degradation of Gas Turbine . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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103
103
103
105
110
111
116

120
120
124
127
127
129
130
131
134
137
137
138
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139
140
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140
142

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6 Configurations of Solar Gas Turbines . . . . . . . . . . . . . . . . . . . . .
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2 Solar-Only Gas Turbine Systems . . . . . . . . . . . . . . . . . . . . . .
6.2.1 Solar-Only Gas Turbine with Recompression
and Inter-cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2.2 Solar-Only Gas Turbine with Fixed and Free Turbines
6.2.3 Solar-Only Gas Turbine with Free Turbine
and Reheating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3 Hybrid Solar Gas Turbine Systems . . . . . . . . . . . . . . . . . . . .
6.3.1 Hybrid Solar Gas Turbine with Recompression
and Inter-cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.2 Hybrid Solar Gas Turbine System with High
and Low Pressure Turbines . . . . . . . . . . . . . . . . . . . .

. . . 145
. . . 145
. . . 146
. . . 146
. . . 147
. . . 148
. . . 149
. . . 150
. . . 150

xiv

Contents

6.4 Solar Gas Turbines with Recuperation . . . . . . . . . . .
6.4.1 Solar-Only Gas Turbine with Recuperation . .
6.4.2 Hybrid Solar Gas Turbine with Recuperation
6.4.3 Solar Gas Turbines with Thermal Storage . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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151
151
155
159
161

7 Design and Testing of Solar Gas Turbines . . . . . . . . . . . . . .
7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.2 Basic Theory of Gas Turbine System Design . . . . . . . . . .
7.2.1 Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.2.2 Preliminary Studies . . . . . . . . . . . . . . . . . . . . . . .
7.2.3 Thermodynamic Design Point Studies . . . . . . . . . .
7.2.4 Aerodynamic Design . . . . . . . . . . . . . . . . . . . . . .
7.2.5 Mechanical Design . . . . . . . . . . . . . . . . . . . . . . .
7.3 System Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.3.1 Considerations About Components and Processes .
7.3.2 System Boundaries . . . . . . . . . . . . . . . . . . . . . . .
7.3.3 Optimization Criteria . . . . . . . . . . . . . . . . . . . . . .
7.3.4 Mathematical Model . . . . . . . . . . . . . . . . . . . . . .
7.3.5 Solution Procedure . . . . . . . . . . . . . . . . . . . . . . . .
7.4 Testing of Solar Gas Turbines . . . . . . . . . . . . . . . . . . . . .
7.4.1 Performance Assessment of Concentrating Solar
Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.4.2 Performance Assessment of Gas Turbines . . . . . . .
7.5 Progress in Testing of Solar Gas Turbines . . . . . . . . . . . .
7.5.1 Project Development . . . . . . . . . . . . . . . . . . . . . .
7.5.2 Challenges to Development of Solar Gas Turbines
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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163

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164
165
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177
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183
189
193

193
195
201

8 Economic Performance of Solar Gas Turbines . . . .
8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.2 Project Costs . . . . . . . . . . . . . . . . . . . . . . . . . .
8.2.1 Sunk Cost . . . . . . . . . . . . . . . . . . . . . . .
8.2.2 Contingency Cost . . . . . . . . . . . . . . . . .
8.2.3 Fixed and Working Capital . . . . . . . . . .
8.2.4 Depreciation and Depletion Premium . . .
8.2.5 Project Benefits . . . . . . . . . . . . . . . . . . .
8.3 Indicators of Cost–Benefit Comparison . . . . . . .
8.3.1 Methods Without Time Value of Money .
8.3.2 Methods with Time Value of Money . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Appendix A: Units of Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Appendix B: Selected Constants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217


Abbreviations

AC
AD
ADB
ANN
ASHRAE
ASME
CAD
CAM
CC
CCC
CCGT
CCS
CCSGT
CFC
CLCGT
CLCSGT

COM
COP
CPC
CSP
DC
DEA
DPB
EC
ED
ETBE
FC

Alternating current
Anaerobic digestion
African development bank
Artificial neural network
American society of heating, refrigerating and air-conditioning
engineers
American society of mechanical engineers
Computer-aided design
Computer-aided manufacturing
Combustion chamber
Cash conversion cycle
Combined cycle gas turbine
Carbon capture and storage
Combined cycle solar gas turbine
Chlorofluorocarbons
Closed cycle gas turbine
Closed cycle solar gas turbine
Compressor

Conference of parties
Compound parabolic concentrator
Concentrating solar power
Direct current
Diethanolamine
Discounted payback
External combustion
Electrodialysis
Ethyl-tertio-butyl-ether
Flameless combustion

xv


xvi

GEF
GHG
GT
HEX
HP
HRSG
HTF
HVOs
IC
IEA
IEC
IR
IRR
ISCC

ISGTCPP
ISO
LCOE
LFR
LHS
LP
LR
MDEA
MED
MLR
MSF
MTBE
NDS
NF
NPV
NREL
N-S
OCGT
OCSGT
ORC
PCM
PDC
PI
PID
PM
PMG
ppm
PTC

Abbreviations

Global environment facility
Green house gas
Gas turbine
Heat exchanger
High pressure
Heat recovery steam generator
Heat transfer fluid
Hydrogenated vegetable oils
Internal combustion engine
International energy agency
International electrotechnical commission
Infrared
Internal rate of return
Integrated solar combined cycle
Integrated solar gas turbine cogeneration power plant
International organization for standardization
Levelized cost of energy
Linear Fresnel reflector
Latent heat storage
Low pressure
Linear regression
Methyldiethanolamine
Multi-effect distillation
Multiple linear regression
Multistage flash
Methyl-tertio-butyl-ether
Non-dominated solutions
Nanofiltration
Net present value

National renewable energy laboratory
Navier–Stokes
Open cycle gas turbine
Open cycle solar gas turbine
Organic Rankine cycle
Phase change material
Parabolic dish concentrator
Proportional–integral
Proportional–integral–derivative
Permanent magnet
Permanent magnet generator
Parts per million
Parabolic trough concentrator


Abbreviations

PV
RE
REFOS
RHE
RO
RPM
SCLCGT
SCLCSGT
SCR
SGT
SISGT
SSPS
ST

TRL
UHC
UV
VCD
WRC

xvii

Photovoltaic
Renewable energy
Receiver for fossil-hybrid gas turbine systems
Recuperative/regenerative heat exchanger
Comprises reverse osmosis
Revolutions per minute
Semi-closed cycle gas turbine
Semi-closed cycle solar gas turbine
Selective catalytic reduction
Solar gas turbine
Steam-injected solar gas turbine
Small solar power systems
Solar tower
Technology readiness level
Unburned hydrocarbon
Ultraviolet
Vapour compression distillation
World radiation centre


Nomenclature

A
~
B
C
Ĉ
D
E
Ê
É
Êt
Ě
^e
F
f
g
ĝf0
G
h
ĥ
H
Ĥ
I
~
J
k
L
Ĺ
m
_
m

_
m
n

Area (m2)
Magnetic flux density (T)
Specific heat capacity (kJ kg−1K−1)
Cost (currency)
Diameter (m)
Electric field flux (N m2 C−1)
Energy (J)
Power (W)
Energy produced during year t (kWh)
Exergy flow (W)
Specific exergy flow (W kg−1)
View factor (dimensionless)
Frequency (Hz)
Acceleration due to gravity (m s−2)
Gibbs free energy of formation (kJ mol−1)
Irradiance (Wm−2)
Specific enthalpy (Jkg−1)
Coefficient of heat transfer (Wm−2K−1)
Heating value of fuel (Jkg−1)
Height (m)
Moment of inertia (Nm)
Electric current density (A m−2)
Conductivity (Wm−1K−1)
Specific latent heat (Jkg−1)
Length (m)
Mass (kg)

Mass flow rate (kgs−1)
Mass flux (kg m−2 s−1)
Optical density (dimensionless)

xix


xx

Nomenclature

N
P
Ṕ
q
q_
Q
Q_
Q_ f
r
R
Ȓ
Ŕb
S
s
t
T
U
u
v

W
w

Number
Pressure (Nm−2)
Oil production (Gb/year)
Rate of volumetric heat addition by thermal conduction per unit mass (Jkg−1)
Heat flux (Wm−2)
Heat (J)
Heat rate/power (W)
Energy rate of fuel (kW)
Ratio (dimensionless)
Gas constant (J/mol)
Revenue (currency)
Geometric factor for beam irradiance on a tilted surface (dimensionless)
Characteristic length or equivalent spacing (m)
Entropy (JK−1)
Time (year)
Temperature (K)
Coefficient of heat loss (Wm−2K−1)
Speed in x-direction (ms−1)
Speed in y-direction (ms−1)
Work (W)
Speed in z-direction (ms−1)

Greek Symbols
a
ά
b
b́

v
c
η
u
0
k
l
hp
hn
hf
H
Hsd
q
s

Absorptance (dimensionless)
Thermal diffusivity (m2 s−1)
Angle of inclination (degree)
Coefficient of thermal expansivity (K−1)
Ratio of specific heats (dimensionless)
Solar azimuth angle (degree)
Efficiency (dimensionless)
Density (kg m−3)
Friction factor (dimensionless)
Wavelength of radiation (m)
Dynamic viscosity (Nsm−2)
Angle of incidence (degree)
Angle of refraction (degree)
Angle of reflection (degree)
Longitude of a site (degree)

Standard longitude (degree)
Reflectance (dimensionless)
Transmittance (dimensionless)


Nomenclature

t
x
w
W
Xa
r
m
f

Stoichiometric air–fuel ratio (dimensionless)
Hour angle (degree)
Angular speed (rad s−1)
Proportion of solid PCM melted (dimensionless)
Torque (Nm)
Angular acceleration (rad s−1)
Stefan–Boltzmann constant (W m−2 K−4)
Kinematic viscosity (m2 s−1)
Specific fuel consumption (kg kWh−1)

Subscripts
0
1–n
a

ag
av
bb
bot
bp
c
cc
ch
ci
co
con
com
comb
d
dh
dn
dp
eg
el
eq
f
fp
fs
g
gh
ga

Reference point
First to nth thermodynamic points
Air/ambient

Average
Available
Blackbody
Bottom
Beam on tilted plane
Convective
Combustion chamber
Chemical
Compressor isentropic
Compression
Conduction
Compressor
Combined
Destruction
Diffuse on horizontal surface
Direct normal
Diffuse on tilted plane
Exhaust gas
Electrical/electricity
Equation
Fuel/fuel specific
Feed pump
Free stream
Global
Global on horizontal surface
Gas(es)

xxi

xxii

gen
gr
H
h
htf
i
in
is
l
L
LS
m
mc
mp
net
opt
out
n
p
ph
po
pr
r
ra
rc
re
s
sk

sm
so
st
ss
su
th
ti
tin
to
tot
tr
tu
u
ua
us

Nomenclature

Generator
Ground reflected
Higher
Hydraulic
Heat transfer fluid
Incidence
Inlet
Isentropic
Liquid
Lower
Loss
Mechanical

Mean compressor
Melting point
Net
Optical
Outlet
Normal
Constant pressure
Physical
Pole
Parallel
Radiative
Rankine
Receiver
Reflection/reflector
Solar/sun
Sky
Storage medium
Solid
Steam
Sunset
Surface
Thermal
Turbine isentropic
Turbine inlet
Tower
Total
Transparent medium
Turbine
Useful
Unavailable

Ultrasound


Nomenclature

v
w
wf
z

Vapour
Water
Working fluid
Solar zenith

xxiii


List of Figures

Fig. 1.1
Fig. 1.2

Fig. 1.3
Fig. 1.4
Fig. 1.5
Fig. 1.6
Fig. 1.7

Fig. 1.8

Fig. 1.9

Fig. 1.10
Fig. 1.11

Fig. 1.12
Fig. 1.13

Classification of energy resources . . . . . . . . . . . . . . . . . . . . . .
Fuel share of the world total primary energy supply in 2013.
Other sources of energy include geothermal, heat, solar and
wind. BW = biofuels & waste, NG = natural gas. Data source:
International Energy Agency 2015 . . . . . . . . . . . . . . . . . . . . .
Schematic diagram of a power producing turbomachine . . . . .
Schematic diagram of a power absorbing turbomachine . . . . .
Schematic representation of a simple gas turbine.
CC = combustion chamber, COM = compressor . . . . . . . . . .
One-dimensional heat conduction across a slab of thickness x,
with T1 > T2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Formation of laminar and turbulent boundary layers when
a fluid flows over a flat surface. The velocity of the fluid
increases with the distance from the surface and the edge.
Vfs is free stream flow velocity . . . . . . . . . . . . . . . . . . . . . . . .
a A curved surface exchanges radiation with itself and other
surfaces. b A flat surface exchanges radiation with other
surfaces only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic configurations of flat-plate collectors: a single-pass
(fluid heated from below), b single-pass (fluid heated from
above), c double pass, d fin and tube . . . . . . . . . . . . . . . . . . .

Imaging collector with a reflector type of concentrator . . . . . .
Cross-section of a non-imaging collector with a reflector
type of concentrator. The reflector has two sections
of a parabola . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic representation of a solar gas turbine with steam
injection. CC = combustion chamber . . . . . . . . . . . . . . . . . . .
Recovery of heat from flue gas (which has passed through
a heat recovery steam generator (HRSG) or other heat
exchangers such as a recuperator) by a thermal desalination
system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..

2

..
..
..

3
5
6

..

7

..

9

..

11

..

15

..
..

18
19

..

19

..

21

..

22
xxv


xxvi

Fig. 2.1
Fig. 2.2
Fig. 2.3

Fig. 3.1

Fig. 3.2
Fig. 3.3

Fig. 3.4

Fig. 3.5
Fig. 3.6
Fig. 3.7
Fig. 4.1

Fig. 4.2
Fig. 4.3

Fig. 4.4

Fig. 4.5
Fig. 4.6
Fig. 4.7
Fig. 4.8
Fig. 4.9
Fig. 4.10

Fig. 4.11

Fig. 4.12

List of Figures

Variation of oil production with time for a single cycle . . . . .
Variation of oil production with time for two cycles . . . . . . .
A closed cycle gas turbine fuelled by nuclear reactor: a direct
heating and b indirect heating. COM = compressor and
HEX = heat exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Variation of global irradiance on a horizontal surface on
a sample day (1st January 2007) at Bonfoi Station,
Stellenbosch (33.935°S, 18.782°E) in South Africa . . . . . . . .
Distribution of direct normal irradiation worldwide.
With permission from SOLARGIS . . . . . . . . . . . . . . . . . . . . .
Diagram showing a beam ray from the sun onto an inclined
surface, and solar and surface angles (in the northern
hemisphere) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A Kipp & Zonen pyranometer with a shadow ring mounted on
roof top at Malawi Polytechnic (15° 48’ S, 35° 02’ E):
a pyranometer and b shadow ring . . . . . . . . . . . . . . . . . . . . .
Attenuation of solar radiation by an opaque surface . . . . . . . .
Attenuation of solar radiation by an opaque surface,
a specular reflection and b diffuse reflection . . . . . . . . . . . . . .
Attenuation of solar radiation through a transparent surface . .
Schematic representation of a solar gas turbine, showing
the solar field, Brayton cycle and generator. CC = combustion
chamber, COM = compressor . . . . . . . . . . . . . . . . . . . . . . . . .
Cross-section of an evacuated tube . . . . . . . . . . . . . . . . . . . . .
Schematic representation of a parabolic trough concentrator
a cross-section of trough reflector and tube and b array

of parabolic reflectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic representation of a linear Fresnel reflector:
a perspective view and b cross-section of receiver cavity
around the absorber tube. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic diagram of parabolic dish concentrator . . . . . . . . .
Schematic representation of a solar tower . . . . . . . . . . . . . . . .
Reflection of beam rays on a reflector made of thin
transparent layer and silver layer . . . . . . . . . . . . . . . . . . . . . .
Schematic illustration of a tubular panel . . . . . . . . . . . . . . . . .
Basic principle of operation of a volumetric receiver
with: a porous material and b block of channels . . . . . . . . . .
Schematic representation of a hybrid solar gas turbine
in: a serial configuration with direct heating, b serial
configuration with indirect heating and c parallel
configuration. CC = combustion chamber, HEX = heat
exchanger and M = mixer . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Classification of compressors . . . . . . . . . . . . . . . . . . . . . . . . .
Cross-section of can combustors . . . . . . . . . . . . . . . . . . . . . . .

..
..

31
32

..

45

..

53

..

54

..

55

..
..

59
60

..
..

61
62

..
..

66
67

..

67

..
..
..

68
69
71

..
..

72
74

..

75

..
..
..

77
84
86

List of Figures

Fig.
Fig.
Fig.
Fig.
Fig.

4.13
4.14
4.15
4.16
4.17

Fig. 4.18
Fig. 4.19
Fig. 4.20
Fig. 4.21

Fig.
Fig.
Fig.
Fig.
Fig.

5.1
5.2
5.3
5.4
5.5

Fig. 5.6
Fig. 5.7
Fig. 5.8
Fig. 5.9
Fig. 5.10
Fig. 5.11
Fig. 5.12

Fig. 5.13
Fig. 5.14
Fig. 5.15
Fig. 5.16
Fig. 5.17
Fig. 5.18
Fig. 5.19

Cross-section of annulus combustors . . . . . . . . . . . . . . . . . . .
Cross-section of cannulus combustors. . . . . . . . . . . . . . . . . . .
Cross-section of a radial turbine . . . . . . . . . . . . . . . . . . . . . . .
Cross-sectional view of an axial turbine . . . . . . . . . . . . . . . . .
Block diagram of electromechanical energy conversion
by generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
An example of a simple electrostatic generator, showing
electric field E inside electrets . . . . . . . . . . . . . . . . . . . . . . . .
Schematic cross-section of a radial flux permanent
magnet generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Magnetic field between north (N) and south (S) poles of:
a permanent magnets and b simple inductor . . . . . . . . . . . . . .
A simplified control system of: a solar-only gas turbine

and b solar gas turbine with backup heating. CC = combustion
chamber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
T-S diagram of a generalized fluid . . . . . . . . . . . . . . . . . . . . .
Energy flow in a Carnot cycle . . . . . . . . . . . . . . . . . . . . . . . .
T-S diagram of a Carnot cycle . . . . . . . . . . . . . . . . . . . . . . . .
Ideal Rankine cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Temperature-entropy (T-S) diagram of a standard Rankine
cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rankine cycle with super heating . . . . . . . . . . . . . . . . . . . . . .
Temperature-entropy (T-S) diagram of a Rankine cycle
with superheating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rankine cycle with super heating and re-heating. HP = high
pressure, and LP = low pressure . . . . . . . . . . . . . . . . . . . . . . .
Schematic representation of a engine layout and b T-S
diagram of a simple open cycle gas turbine . . . . . . . . . . . . . .
A solar-only closed cycle gas turbine system.
COM = compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
T-S diagram of a solar-only closed cycle gas turbine . . . . . . .
A hybrid closed cycle solar gas turbine system.
CC = combustion chamber, COM = compressor,
HEX = heat exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
T-S diagram of hybrid closed cycle solar gas turbine . . . . . . .
Solar-only open cycle solar gas turbine system.
COM = compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
T-S diagram of a solar-only open cycle solar gas turbine . . . .
Hybrid open cycle solar gas turbine system.
COM = compressor, CC = combustion chamber . . . . . . . . . .
T-S diagram of a hybrid open cycle solar gas turbine . . . . . .
Semi-closed gas turbine with bottoming cycle . . . . . . . . . . . .
Semi-closed solar gas turbine with bottoming cycle . . . . . . . .

xxvii

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86
87
91
91

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92

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93

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94

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94

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98
104
104
104
105

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121
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xxviii

Fig. 5.20
Fig. 5.21
Fig. 5.22
Fig. 5.23
Fig. 6.1
Fig. 6.2

Fig. 6.3

Fig. 6.4

Fig. 6.5

Fig. 6.6
Fig. 6.7
Fig. 6.8

Fig. 6.9
Fig. 6.10
Fig. 6.11

Fig. 6.12
Fig. 6.13
Fig. 7.1

Fig. 7.2

List of Figures

Schematic view of a combined cycle with a closed
topping Brayton cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic view of a combined cycle gas turbine
with a heat recovery steam generator (HRSG) . . . . . . . . . . . .
T-S diagram of a combined cycle with open topping Brayton
cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Effect of ambient temperature on power output and heat
rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Single-spool solar-only gas turbine with recompression
and inter-cooling: a closed cycle and b open cycle . . . . . . . .

Twin-spool solar-only gas turbines: a closed cycle
and b open cycle. HP = high pressure, and LP = low
pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Twin-spool solar-only gas turbines with fixed and free
turbines: a closed cycle and b open cycle . . . . . . . . . . . . . . .
Twin-spool solar-only gas turbines with a free turbine and
reheating: a closed cycle, and b open cycle.
COM = compressor, HEX = heat exchanger, HP = high
pressure, and LP = low pressure . . . . . . . . . . . . . . . . . . . . . . .
Twin-spool solar-only gas turbines with reheating: a closed
cycle and b open cycle. COM = compressor, HP = high
pressure, and LP = low pressure . . . . . . . . . . . . . . . . . . . . . . .
Hybrid solar gas turbine system with two compression
Stages: a closed cycle and b open cycle . . . . . . . . . . . . . . . . .
Twin-spool hybrid solar gas turbine system with fixed
and free turbines: a closed cycle and b open cycle . . . . . . . . .
Twin-spool hybrid solar gas turbine system with high (HP)
and low (LP) pressure turbines: a closed cycle and b open
cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Solar-only closed cycle gas turbine system with recuperator.
COM = compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Solar-only open cycle solar gas turbine system with
recuperator. COM = compressor . . . . . . . . . . . . . . . . . . . . . . .
Closed cycle solar gas turbine system with recuperator.
COM = compressor, HEX 1 = heat exchanger 1, HEX
2 = heat exchanger 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Open cycle solar gas turbine system with recuperator. . . . . . .
Solar-only gas turbine with thermal storage component:
a solar-only open cycle, and b hybrid open cycle. . . . . . . . . .
Flowchart showing design phases and iterative links,

mods = modifications. Adapted from Budynas and Nisbett
(2011) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic representation of flow pattern: a through a duct
and b over a surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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