Download Design and Sizing of Solar Thermal Power Plant (STPP

International Journal on Power Engineering and Energy (IJPEE)
ISSN Print (2314 – 7318) and Online (2314 – 730X)
Vol. (5) – No. (4)
October 2014
Design and Sizing of Solar Thermal
Power Plant (STPP) in Egypt
Faten Hosney Fahmy, Hanaa Mohamed Farghally, Ninet Mohamed Ahmed
Electronics Research Institute, Giza, Egypt.
[email protected], [email protected], [email protected]
Abstract - Solar thermal power is a prime
choice in developing an affordable, feasible,
global energy source that is able to substitute
for fossil fuels in the sunbelts around the
world. Solar thermal technologies, especially
parabolic trough concentrators (PTC) are
more convenient for concentrating power
station. This paper presents the design and
sizing of a parabolic trough solar thermal
electric power plant with a net capacity of 1
MW using direct steam generation in one of
Suez Suburbs in Egypt. 1 MW electric power
generated during the day sunny periods is
used to feed a small local grid in a suburb of
Suez. A EUROTROUGH solar collector is
used, it is found that, the solar field is
constituted of 40 collectors grouped in 10
loops, and the estimated solar field area is
22680 m2. Also, this study includes a
thermodynamic analysis of a vapor power
plant and the Rankine cycle of 1 MW steam
power plant is modeled and analyzed. The oil
and steam mass flow rates are found to be
2.252 kg/s and 1.4 kg/s respectively. The
thermal efficiency of the parabolic trough
solar collector (PTSC) is found to be 71% and
the total plant efficiency is 28. 3%.
Keywords- solar energy, parabolic trough
collector, power plant, Rankine cycle.
1. INTRODUCTION
Pollution and increasing fuel prices are the
main focus for governments today. Therefore,
the world must move swiftly towards the clean
and economical natural energy sources.
Renewable power generation can help countries
to meet their sustainable development goals
through provision of access to clean, secure,
reliable and affordable energy. A new strategy
should be applied in the coming decades based
on the integration of existing power plants with
renewable energy sources, such as solar and
wind energy.
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The benefits of solar power are compelling:
environmental protection, economic growth, job
creation, diversity of fuel supply and rapid
deployment, as well as the global potential for
technology transfer and innovation [1-3]. The
underlying advantages of solar energy are that
the fuel is free, abundant and inexhaustible. The
total amount of energy irradiated from the sun to
the earth’s surface is enough to provide for
annual global energy consumption 10,000 times
over [4-6].
The main cause of pollution is existing
electricity power plants that use huge quantities
of fossil fuel. Solar thermal energy (STE) is a
technology for harnessing solar energy for
thermal energy (heat). Solar thermal collectors
are classified by the United States Energy
Information Administration as low, medium and
high temperature collectors. Low-temperature
collectors are flat plates generally used to heat
swimming pools. Medium-temperature collectors
are also usually flat plates but are used for
heating water or air for residential and
commercial use. High-temperature collectors
concentrate sunlight using mirrors or lenses are
generally used for electric power production [68].
Concentrating solar thermal power is a global
scale technology that has the capacity to satisfy
the energy and development needs of the world
without destroying it. Solar thermal power uses
direct sunlight, so it must be sited in regions with
high direct solar radiation. Among the most
promising areas of the world are the SouthWestern United States, Central and South
America, Africa, the Middle East, the
Mediterranean countries of Europe, Iran,
Pakistan and the desert regions of India, the
former Soviet Union, China and Australia [9-12].
Concentrated Solar Power (CSP) technologies
are usually categorized in three different
concepts: Troughs, Towers and Dishes. Among
them Parabolic Trough Solar Collector (PTSC) is
currently the most proven solar thermal electric
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technology. This paper presents the design and
sizing of a parabolic trough solar power plant
with a net capacity of 1 MW using direct steam
generation in Suez Suburb, Suez city in Egypt.
Also, the Rankin cycle of 1 MW steam power
plant is analyzed and modeled.
II. LOCATION DATA
One of the Suez Suburbs is selected as the site
under consideration; Suez Suburbs are
characterized by a rich solar radiation and
moderate wind speed. Suez Suburbs are
a seaport Suburbs in north-eastern Egypt, located
on the north coast of the Gulf of Suez near the
southern terminus of the Suez Canal. Its
elevation, longitude and latitude are 6 m, 29°58′
N and 32°33′ E respectively. Its low and high
temperature is shown in Figure (1). It is observed
that, the monthly average low temperature
ranged between 8oC and 23oC, and the monthly
average high temperature ranged between 19 oC
and 36 oC [13]. Suez enjoys sunshine all year,
with direct solar radiation which reaches 6
KWh/m2/day. Also, the average wind speed is
around 5.5 m/s [14].
Figure (1): Monthly average high and low
ambient temperatures for Suez Suburbs.
III SYSTEM DESCRIPTION
There is a striking resemblance between
conventional fossil-fuel power plant and Solar
Thermal Power Plant (STPP), the difference lies
in the mode of heat generation. While
conventional power generation derives its heat
source from the burning of fossil fuels, STPP
uses radiant energy from the sun. A description
of STPP is illustrated in Figure (2). The main
elements of the plant are: the solar field
(parabolic trough solar collectors), power block
which includes heat exchanger (as solar boiler),
turbine, condenser, pump and generator. A heat
transfer fluid (HTF) is heated as it circulates
through the receiver and returns to a series of
heat exchangers in the power block where the
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fluid is used to generate high-pressure steam.
The steam is then fed to turbine/generator to
produce electricity. The spent steam from the
turbine is condensed in a standard condenser
and returned to the heat exchangers via
condensate and feedwater pumps to be
transformed back into steam. Condenser
cooling is provided by mechanical draft wet
cooling tower.
Figure (2): Description of solar thermal power
plant (STPP).
A. Solar Field
The solar field is the heat-collecting portion of
the plant. The major component of any solar
system is the parabolic trough solar collector. It
consists of one or more loops of solar collector
assemblies (SCA’s), with each loop laid out in
parallel. Solar energy collectors are special kinds
of heat exchangers that transform solar radiation
energy to internal energy of the transport
medium. They absorb the incoming solar
radiation, convert it into heat, and transfer the
heat to a fluid (oil) flowing through the collector.
In this study, the solar field is used as a heat
source for power plant to generate 1 MW electric
power during the day sunny periods to feed a
small local grid in a suburb of Suez. PTSC is
currently the most proven solar thermal electric
technology widely used in generating power for
Rankine cycle to produce power for electric
generation. Parabolic-trough collectors (PTC) are
frequently employed for solar steam-generation
because temperature of about 200-300oC can be
obtained without any serious degradation in the
collector's efficiency. A Parabolic trough
collector as shown in Figure (3) consists of a
reflecting surface mounted on a reflector support
structure having the profile of a parabola. A
receiver assembly, comprising a circular
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absorber tube with suitable selective coating and
enclosed in a concentric glass envelope, is
centered along the reflector focal line [15].
Figure (4): Shell and tube heat exchanger
configuration
Figure (3): Parabolic trough solar collector.
B. Heat Exchanger (as solar boiler)
A shell and tube heat exchanger is the most
common type of heat exchanger in oil refineries
and other large chemical processes, and is suited
for higher-pressure applications. As its name
implies, this type of heat exchanger consists of a
shell (a large pressure vessel) with a bundle of
tubes inside it. One fluid runs through the tubes,
and another fluid flows over the tubes (through
the shell) to transfer heat between the two fluids.
The set of tubes is called a tube bundle, and may
be composed of several types of tubes: plain,
longitudinally finned, etc. Two fluids, of
different starting temperatures, flow through the
heat exchanger. One flows through the tubes (the
tube side) and the other flows outside the tubes
but inside the shell (the shell side). In this study,
oil is used as a heat transfer fluid (HTF) is flows
inside the shell, while the saturated steam which
is the working fluid is flows through the tubes. .
Figure (4) illustrates the composition of a shell
and tube heat exchanger. Heat is transferred
from one fluid to the other through the tube
walls, either from tube side to shell side or vice
versa [16].
Reference Number: JO-P-0056
A counter flow heat exchanger is the most
efficient flow pattern. It leads to the lowest
required heat exchanger surface area because the
log mean temperature drop is the highest for a
counter flow heat exchanger. Figure (5)
illustrates the inlet and outlet temperatures of the
two fluids (oil and steam) in a counter flow heat
exchanger.
Figure (5): The terminal temperature of oil and
steam fluids in a counter flow heat exchanger.
a. Selection of Heat Transfer Fluid
Parabolic trough solar collectors utilize an HTF
that flows through the receiver to collect the
solar thermal energy and transport it to the power
block. The type of HTF used determines the
operational temperature range of the solar field
and thus the maximum power cycle efficiency
that can be obtained. Table 1 shows the available
HTF options.
Synthetic oil such as a mixture of biphenyl and
diphenyl oxide (Therminol VP-1) is selected one.
It is
pumped through each heat collection
element (HCE) tube. The heated HTF is pumped
back to the power plant, where it becomes the
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thermal resource for steam generation in the
power cycle. Within the power cycle portion of
the plant, the hot HTF is piped through a series
of counter flow heat exchangers that transfer the
thermal energy from the HTF to a feedwater
stream to produce steam. This steam serves as
the working fluid in a conventional Rankine
power cycle [11].
Table 1 Heat transfer fluids with application in
solar parabolic trough fields [17]
b. Selection of the Working Fluid
The selection of the optimum working fluid that
can be used with the solar operated Rankine
cycle depends on of staging many criteria and
the most important of which is the maximum
temperature of the cycle. Other criteria include
the following [18-19]:
1. High molecular weight to reduce the nozzle
velocity and thus enable the use of a low speed
turbine without the necessity of the expander (the
nozzle velocity is inversely proportional to the
square root of the molecular weight).
2. Reasonable pressure corresponding to the
boiling temperature of the fluid. High pressure
requires careful sealing to avoid leakage.
3. Dry expansion, i. e positive slope of the
vapour saturation curve on the T-S diagram, to
assure that all the expansion states in the turbine
exist on the superheat region.
4. High latent heat to give high specific
consumption of the working fluid and therefore
reduce the size of the plant for a given power
output.
5. Fluid compatible with the seals, lubricant oil,
and materials of the various components.
6. Thermal and chemical stability at the
temperature range of operation.
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7. Inexpensive, non-corrosive, non- flammable,
and non-toxic fluid.
8. Thermodynamic properties that lead to the
highest possible efficiency of the system at the
selected temperature range of the cycle.
9. Reasonable pressure at the condensing
temperature (usually about 50 oC). Very low
pressure in the condenser requires special case of
sealing.
Table 2 compares the properties of some
suggested working fluids for the Rankine cycle.
In this study, we chose water as a working fluid.
Water as working fluid is very convenient
compared to organic fluids. It is inexpensive,
non-toxic, nonflammable, has low global
warming potential and zero ozone depleting
potential, chemically stable and low viscosity
(and thus lower friction losses and higher heat
exchange coefficients). However, a watertreatment and a deaerator must be integrated with
the power plant to feed the cycle with highpurity deionized, oxygen free water. Organic
fluids may be relatively toxic and is more
expensive than water (excluding cost of pretreatment).
Table 2 Some suggested working fluids for the
Rankine cycle [11].
C. Turbine
Steam enters the turbine at a high temperature
and high pressure state. The expansion of the
steam as it moves from high pressure to lower
pressure converts the potential energy (in the
form of pressure) to kinetic energy by imparting
its momentum to the turbine blades, thereby
causing the connected shaft to rotate. The
mechanical work created by the rotating shaft is
converted to electrical energy through a
generator.
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D.
Electromechanical
Energy
Transfer
(Generator)
The steam turbine drives a generator, to convert
the mechanical energy into electrical energy.
Typically this will be a rotating field
synchronous machine.
E. Condenser
The exhaust steam from the low pressure
turbine is condensed to water in the condenser
which extracts the latent heat of vaporization
from the steam reducing the pressure
dramatically to near vacuum conditions thus
increasing the pressure drop across the turbine
enabling the maximum amount of energy to be
extracted from the steam. The condensate is then
pumped back into the heat exchanger as feedwater to be used again. It goes without saying
that condenser systems need a constant, of
cooling water and this is supplied in a separate
circuit from the cooling tower which cools the
condenser cooling water by direct contact with
the air and evaporation of a portion of the
cooling water in an open tower.
F. Pump
The pump being a component in a Rankine
cycle which is needed to raise the pressure of the
liquid leaving the condenser to the pressure of
the steam generator. Since pump work is
inversely proportional to the fluid density, less
work is required to pressurize a liquid than a
vapour or gas. The ideal pump raises the pressure
of a liquid in an adiabatic, reversible process.
IV. RANKINE CYCLE OF PARABOLIC
TROUGH SOLAR THERMAL POWER
PLANT
The Rankine cycle is the fundamental operating
cycle of all power plants where an operating
fluid is continuously evaporated and condensed.
The selection of operating fluid depends mainly
on the available temperature range. Rankine
cycle used in thermal power plants deals on
heating up water in constant pressure while
changing its phase. The thermodynamic analysis
of a Rankine cycle for the steam power plants
based on the first and second laws of
thermodynamic. All four components (turbine,
condenser, pump and heat exchanger) that make
up ideal Rankine cycle are steady-flow devices,
and thus all four processes that make up the
Rankine cycle can be analyzed as steady-flow
processes. The kinetic and potential energy
changes of water are small relative to the heat
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and work terms, are thus neglected [20].
Schematic representation of an ideal Rankine
cycle and the temperature – specific entropy (T–
s) diagram for the thermodynamic processes of a
standard irreversible Rankine cycle is shown in
Figure (6) [21]. The working fluid undergoes the
following series of internally reversible
processes:
Process 1–2: Isentropic expansion of the working
fluid through the turbine from saturated vapor at
state 1 to the condenser pressure.
Process 2–3: Heat transfer from the working
fluid as it flows at constant pressure through
the condenser with saturated liquid at state 3.
Process 3–4: Isentropic compression in the pump
to state 4 in the compressed liquid region.
Process 4–1: Heat transfer to the working fluid
as it flows at constant pressure through the heat
exchanger to complete the cycle.
Figure (6a): Schematic representation of an ideal
Rankine cycle.
Figure (6b): T-S diagram of an ideal Rankine
cycle.
The net power delivered by the Rankine cycle is
the difference between the turbine power and the
magnitude of the pump power. One of the
significant advantages of the Rankine cycle is
that the pump power is usually quite small
compared with the turbine power. This is
indicated by the work ratio, wt / wp, which is
large compared with one for Rankine cycle. As a
result, the pumping power is sometimes
neglected in approximating the Rankine cycle
net power output.
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V. MODELING OF SOLAR THERMAL
POWER PLANT (STPP)
In this section we will introduce the model of
solar field; heat exchanger and power block
Rankine cycle .
A. Solar field modeling
The design of a solar field is influenced by the
industrial process, the technical characteristics of
the selected collectors, the location of the plant
and the climate data. The solar field consists of a
number of parabolic trough collector loops
connected in parallel to each other. Each loop
consists of several solar collector assemblies
(SCA) in series, in one or several rows. The solar
collector efficiency can be determined from its
characteristic using the solar irradiance. The
solar collection efficiency (ηth) is defined as the
ratio of the rate of useful thermal energy leaving
the collector, to the useable solar irradiance
falling on its aperture area. Simply stated
collector efficiency and is calculated as follows
[22-25]:
th =
 oilCp (Tout −Tin)
Qu Qu m
=
=
Qi Ib Aa
Ib Aa

Q
abs = A a η opt I dn
(2)
The nominal temperature increase in a collector
of the EUROTROUGH type is calculated using
the following equation.
Q t − Q p
Q
(3)
oil
 =C m
 oil
Q
oil
p oil
(4)
Where:
Qt
power lost by a collector [W];
power absorbed by the oil [W/grd];
C p oil
oil specific heat at constant pressure
[J/kg K];
m oil
is mass flow rate for a collecting loop
[kg/s];
Pt
is thermal power [W].
The number of collectors for a loop (N) is
calculated with the following relation:
N=
∆Tloop
(5)
∆Tcolec
Where, ∆Tloop is the heat jump in one loop of
collectors, ∆Tcolec is the heat jump in only one
collector. The calculation of the number of
parallel loops (M) in the solar field can be
described by:
M
Where, Aa is the absorbed area of the collector
(m2), ηopt is the optical efficiency and Idr solar
irradiance falling on collector aperture (W/m2)
∆ T colec =
Qp
Qoil
(1)
Where, the useful energy Qu is the difference
between the energy absorbed at the receiver tube,
and the energy losses at the receiver, Qi is the
incident energy.
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October 2014
=
P t . 10 6
Q t − Q p
(6)
N
 oil C p oil (Tpb inlet − Tpb outlet )
Poil = m
(7)
p thermal = p oil steamgen
(8)
Where,
Tpb inlet Tpb outlet
,
are the inlet and outlet
temperatures of the power block,
steam generation efficiency.
 steamgen
is the
B. Heat exchanger modeling
The HTF used is synthetic oil, namely Therminol
VP-1, which is a mixture of biphenyl and
diphenyl oxide and
stable at temperatures
below 400°C. The temperature of the HTF
increases of around 160°C, from 70°C to 230°C.
Also, the condensed water entered the heat
exchanger at 50 oC and exit as saturated steam at
200 oC. The fundamental equation for heat
transfer across a surface of heat exchanger is
given by [26]:
power generated by a collector [W];
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 steam C p steam ( t 2 − t 1 ) = m
 oil c p oil (T1 − T2 )
Q=m
Where
Q
Btu/h);
(9)
 =0
Q
cv
g( Z1 − Z 2 ) = 0
heat transferred per unit time (kJ/h,
C p oil
specific heat of oil;
C p steam
specific heat of steam (kJ/kg-ºK, Btu/lb-
 2
2
 V 1− V 2 

=0
2




ºF);
Therefore,
m steam mass flow rate of steam;
m oil
Wt
= h1 − h2
m
mass flow rate of oil;
T1
inlet shell side fluid (oil) temperature;
T2
outlet shell side fluid (oil) temperature;
t1
inlet tube side fluid (water )
temperature;
t2
outlet tube-side (steam) temperature.
C. Rankine cycle mathematical model
The principal work and heat transfers of Rankine
cycle solar power plant are illustrated in Fig. 6.
In subsequent discussions, these energy transfers
are taken to be positive in the directions of the
arrows. The unavoidable stray heat transfer that
takes place between the plant components and
their surroundings is neglected here for
simplicity. Kinetic and potential energy changes
are also ignored. Each component is regarded as
operating at steady state. Using the conservation
of mass and conservation of energy principles
together with these idealizations, we develop
expressions for the energy transfers shown on
Fig 6 beginning at state 1 and proceeding
through each component in turn. The
mathematical model of the Rankine cycle units
in Fig. 6 is introduced as follows:
a.
Turbine: Vapor from the heat exchanger
at state 1, having an elevated
temperature (200 oC) and pressure (1.55
MPa), expands through the turbine to
produce work and then is discharged to
the condenser at state 2 with relatively
low pressure (0.012 MPa). Neglecting
heat transfer with the surroundings, the
mass and energy rate balances for a
control volume around the turbine
reduce at steady state to give [27-31]:


2
2


V1−V2


 h1 −h2 +
0 = Qcv −Wt +m
+g(Z1 −Z2)
2




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(10)
(11)
Where, h1 (obtained from steam table) and h2 are
the specific enthalpies of the working fluid at the
inlet and outlet of the turbine respectively [32].
 denotes the mass flow rate of the working
m
 m

W
t
fluid (steam), and
is the rate at which
work is developed per unit of mass of steam
passing through the turbine. As noted above,
kinetic and potential energy changes are ignored.
h2 is obtained according to the following
equation:
h2 = h f + x 2 h fg
(12)
The quality of stage 2 (x2) is obtained from the
following equation:
x2 =
S2 − S f
Sg − S f
(13)
Where, Sf , Sg are obtained from steam table and
they are corresponding to the liquid and vapor
entropy at turbine outlet respectively [32 ].
b. Condenser: In the condenser there is heat
transfer from the vapor to cooling water flowing
in a separate stream. The vapor condenses and
the temperature of the cooling water increases.
The cooling water enters the condenser at 15 oC
and exits at 50 oC. At steady state, mass and
energy rate balances for a control volume
enclosing the condensing side of the heat
exchanger give as:

Q
out
= (h 2 − h 3 )

m
(14)
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Where, h3 is the specific enthalpy of the working
fluid at the outlet of the condenser. It
is
corresponding to 50 oC of saturated liquid at
condenser output and it is obtained from steam

Q
out
 is the rate at which energy is
m
table [32].
transferred by heat from the working fluid to the
cooling water per unit mass of working fluid
passing through the condenser. This energy
transfer is positive in the direction of the arrow
on Figure (6).
c. Pump: The liquid condensate leaving the
condenser at state 3 is pumped from the
condenser into the higher pressure heat
exchanger (boiler). Taking a control volume
around the pump and assuming no heat transfer
with the surroundings, mass and energy rate
balances given as:
W p
(15)
= h4 − h3
m
h4 is the specific enthalpies of the working fluid

W
p
 is the rate of
m
at the outlet of the pump,
power input per unit of mass passing through the
pump. This energy transfer is positive in the
direction of the arrow on Fig. 6. h4 can be
obtained according to the following two
equations:
h4 = h3 + W p / m
h4 = h3 + W p / m = h3 +  3 ( p4 − p3 )
(16)
(17)
d. Heat Exchanger: The working fluid completes
a cycle as the liquid leaving the pump at state 4,
heat exchanger feedwater, is heated to saturation
and evaporated in the heat exchanger. Taking a
control volume enclosing the heat exchanger
tubes carrying the feedwater from state 4 to state
1, mass and energy rate balances is given as
follow:
Q in
= h1 − h4
m
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(18)
Where

Q
in
Vol. (5) – No. (4)
October 2014
 is the rate of heat transfer from
m
the energy source into the working fluid per unit
mass passing through the heat exchanger.
e. Thermal Efficiency: A measure of the
effectiveness of an energy conversion device is
its thermal efficiency .The thermal efficiency
gauges the extent to which the energy input to
the working fluid passing through the heat
exchanger is converted to the net work output, it
is defined as the ratio of the cycle net work to the
heat supplied from external sources. Thus, by
using Equations (12), (13), and (18) we can
express the ideal Rankine-cycle thermal
efficiency in terms of cycle enthalpies as:
=
 /m
 /m
 −W
 (h1 − h2) − (h4 − h3)
W
t
p
=
 /m

Q
(h1 − h4)
in
(19)
The net work output equals the net heat input.
Thus, the thermal efficiency can be expressed
alternatively as:
η=
 /m
 /m
 /m
 −Q


Q
Q
in
out
= 1 − out
 /m
 /m


Q
Q
in
in
= 1−
(h 2 − h 3 )
(h 1 − h 4 )
(20)
(21)
Another parameter used to describe power plant
performance is the back work ratio, or bwr,
defined as the ratio of the pump work input to
the work developed by the turbine. The back
work ratio for the power cycle of Fig. 6 is
expressed as:
bwr =
 /m
 (h 4 − h 3 )
W
p
=
 /m
 (h 1 − h 2 )
W
t
(22)
The mass flow rate is obtained from the
following formula:
 =
m
Wcycle
( h 1 − h 2 ) − ( h 4 − h 3)
(23)

Q
Alternatively, out can be determined from an
energy rate balance on the overall vapor power
plant. At steady state, the net power developed
equals the net rate of heat transfer to the plan:
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


W
cycle = Wt − Wp
(24)
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October 2014
Table3: Data of the solar field
Or



W
cycle = Q in − Q out
(25)
 =Q
 −W

Q
out
in
cycle
(26)
VI. RESULTS AND DISCUSSIONS
The obtained results of sizing and analysis of
STPP Will be presented and discussed in the
following subsections.
6.1 Sizing of a Solar Field of Parabolic Trough
Collector
The sizing of parabolic trough collector solar
field is based on the lowest ambient temperature
of Suez suburb during the sunny period witch is
around 8 oC. The sizing of a solar field consists
of determining the number of collectors
necessary for a loop of the solar field and the
number of necessary loops so as to obtain the
pressure and temperature conditions of the fluid
when exiting the solar field. The temperature
increase of the fluid between the entrance and
exit points determines the number of collectors
per loop, whereas the thermal power that has to
be supplied by the entire solar field determines
the number of loops in the solar field. The
selected model is EUROTROUGH with an
overall length of 100 m, and opening width of
5.67 m. It is found that, the solar field size
required to produce 1 MWe electricity is an array
of a Eurotrough parabolic trough collector
consists of a parallel 10 loops each loop is a
string of 4 collectors and the total required area
is 22680 m2. Table 3 presents the technical
characteristics of solar field. Also, table 4
presents the parabolic trough collector system
specifications.
Table4: Parabolic trough collector system
specifications [22]
6.2 Heat Exchanger
Equation 9 is used to calculate the mass flow rate
m
of heat transfer fluid oil , also the parameters of
the two fluids passing through the heat
exchanger are illustrated in table 5.
Table 5: Heat exchanger data
6.3 Rankine Cycle
According to the specified temperatures of heat
transfer fluid and working fluid, the obtained
parameters of RC considered in this study are
given in table 6.
Reference Number: JO-P-0056
508
International Journal on Power Engineering and Energy (IJPEE)
ISSN Print (2314 – 7318) and Online (2314 – 730X)
Table 6: Calculated parameter of RC power plant
Vol. (5) – No. (4)
October 2014
[3] K. Azizian, M. Yaghoubi, R. Hesami, P.
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7. CONCLUSION
The parabolic trough solar collector is one of the
main technologies currently used in the solar
electric power generation plants. This paper
presents the design and sizing of a parabolic
trough solar thermal power plant with a net
capacity of 1 MW using direct steam generation
in one of Suez Suburbs in Egypt to feed a small
local grid in this Suburb during the day sunny
period. The thermal cycle uses a heat transfer
fluid (synthetic oil) to transfer energy from the
collector field to a Rankine steam cycle via a
heat exchanger. The thermal efficiency of the
PTSC is found to be 71% and the total plant
efficiency is 28. 3%.
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