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1. MODELING OF SOLAR-STEAM ENGINE SYSTEM USING PARABOLIC
CONCENTRATOR
Asma Anjum
Bachelor of Engineer in Electrical and Electonics Engeneering
Rajiv Gandhi Institute of Technology, Rt-nagar , Bangalore-560032,India
asma99.anjmsignature@gmail.com
Abstract—
In India, Concentrated Solar Power Technologies are
primarily used for heating applications. But, actually CSP
Technology has huge potential and can be used for electricity
generation with good returns and better efficiency. Among all the
Concentrated Solar Power Technologies, Solar dish – steam
engine systems are the most feasible one.
In this paper the modeling, fabrication and testing of a
parabolic dish solar steam generator is modeled. The parabolic
dish has been used as a carrier for reflective material. The dish
concentrates the solar radiations and focuses at the Boiler. The
boiler constitutes of water which due to high temperature
converts into steam. The steam is essentially utilized to run the
oscillating type steam engine, which is coupled to a dc generator
to produce electrical power. This model or set-up is intended to
be implemented as a stand-alone model for rural areas. It will be
helpful for providing electricity as well as thermal energy in form
of hot water for rural needs. In this way the overall rural
electrification can be achieved.
1. INTRODUCTION
Access to electricity is one of the most basic necessities of each and
every individual but, unfortunately many of us still lack access to
electricity. The reasons are many like insufficient generation, lack of
wide distribution network, remote location, depletion of conventional
resources, etc. To tackle these situations and to provide electricity
access to all renewable sources like Solar Energy, Wind, Geo-
thermal, Bio-mass etc. are being explored and harnessed. Among all
the available renewable energy sources, solar energy is the one of the
most abundant source of energy, creating a huge scope for its
research development and implementing for generation of energy.
Solar Energy Technology has an important role to play in the present
Energy and Environment crises. Solar Concentrator Technology has
good potential for various applications, including power generation
and process heating applications. Parabolic Solar Dish Concentrators
(PDSCs) can be very useful in Industrial Process Heat applications,
which use about 20% of total oil consumption in India. If only 25%
to 30% of this can be saved by putting up Solar Concentrators, it will
save import of 4.5 MT oil per year, which is about 6% of our oil
imports.
So, solar concentrator for process heat requirements of community,
industrial and commercial establishments is an emerging and exciting
opportunity in India, which is gaining attention from scientists,
engineers and developers. Solar Energy can be utilized through Solar
Photovoltaic and Solar Thermal Systems. Solar Photovoltaic Systems
Generate electricity through photovoltaic (PV) cells. This technology
directly converts sunlight into electricity. Some of the main
drawbacks for the solar technologies are the high investment cost and
long payback period. Solar Thermal Systems can be Flat Plate type
(for low temperature ranges) or Concentrator type (for medium and
high temperature ranges), which shows considerable potential as best
options to overcome the crisis / problems. Concentrating solar
power (CSP) is a unique renewable energy technology. CSP systems
have the ability to provide electricity, refrigeration and water
purification in one unit. This technology will be extremely helpful in
improving the quality of life for many people around the world. It
will help them to get access to electricity, which is the basic necessity
of today’s world.
Concentrating Solar Power (CSP) technologies use mirrors to
concentrate (focus) the sun's light energy and convert it into heat to
create steam to drive a turbine that generates electrical power. The
plants consist of two parts: one that collects solar energy and converts
it to heat, and another that converts the heat energy to electricity as
shown in fig-1.
Fig. 1: Block diagram of concentrated solar power.
ISBN-13: 978-1537584836
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Proceedings of ICAER-2016
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2. Classification of Concentrated Solar Power:
There are four main CSP technology families that can be
Classified according to the way they focus the sun’s rays and the
receiver technology.
 PARABOLIC TROUGH:
A parabolic trough consists of a linear parabolic reflector
that concentrates light onto a receiver positioned along the
reflector's focal line as shown in fig 2. The receiver is a
tube positioned directly above the middle of the parabolic
mirror and filled with a working fluid. The reflector follows
the sun during the daylight hours by tracking along a single
axis. A working fluid (e.g. molten salt) is heated to 150–
350 °C (300–660 °F) as it flows through the receiver and is
then used as a heat source for a power generation system.
Trough systems are the most developed CSP technology.
Fig. 2: Parabolic trough
 POWER TOWER/CENTRAL TOWER:
A solar power tower consists of an array of dual-axis
tracking reflectors (heliostats) that concentrate sunlight on a
central receiver atop a tower; the receiver contains a fluid
deposit, which can consist of sea water. The working fluid in the
receiver is heated to 500–1000 °C (773–1,273 K (932–1,832
°F)) and then used as a heat source for a power generation or
energy storage system . An advantage of the solar tower is that
the reflectors can be adjusted instead of the whole tower. Power-
tower development Fig -3 Parabolic Trough
Fig. 3: Power tower
 LINEAR FRESNEL REFLECTORS: Fresnel reflectors
are made of many thin, flat mirror strips to concentrate
sunlight onto tubes through which working fluid is
pumped. Flat mirrors allow more reflective surface in the
same amount of space as a parabolic reflector, thus
capturing more of the available sunlight, and they are much
cheaper than parabolic reflectors. Fresnel reflectors can be
used in various size CSPs as shown in fig 4.
Fig. 4: linear fresnel reflector
 PARABOLIC DISH SYSTEM:
A parabolic dish engine system consists of a stand-alone parabolic
reflector that concentrates light onto a receiver positioned at the
reflector's focal point as shown in fig 5. The reflector tracks the Sun
along two axes. The working fluid in the receiver is heated to 250–
700 °C (480–1,300 °F) and then used by a Heat engine to generate
power. Parabolicdish systems provide high solar-to-electric
efficiency (between 31% and 32%), and their modular nature
provides scalability.
Fig. 5: Parabolic dish engine system
2. METHODOLOGY
In solar dish concentrator concentrates, the incoming solar radiation
are incident at its focal point where the boiler is placed. As the
temperature inside boiler increases, water inside gets converted into
steam, which is utilized to drive the steam engine. The flywheel of
the engine is coupled to a dc generator which generates power as
ISBN-13: 978-1537584836
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Proceedings of ICAER-2016
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3. shown in block diagram fig-6. A power conditioning unit (PCU) is
connected to the supply of the generator in order to regulate the
voltage output. The PCU consists of 7085 voltage regulator and two
capacitors for filtering and charge storing purpose. The thermal losses
from the boiler can be reduced by using proper insulation to the
boiler. Further, the engine losses can be minimized by improvising
the system and implementing slope condensate method.
Fig. 6: Block diagram of the model
Concentrator Dish: It is a parabolic reflective surface,
metalized glass or aluminum sheets, reflects incident solar
radiation to a small region called the focus (focal point). The
size of the solar concentrator for Dish-Steam Engine system
is determined by the engine. In this case, a small parabolic
concentrator having opening mean diameter of 0.625 m is
modeled and its properties are studied.
Fig. 7: The working model
A parabolic dish is collected and thoroughly polished. A 2.5mm
thick glass mirror is cut into 0.5*0.5 square inch pieces. The glass
pieces were glued on the parabolic dish in proper alignment. The
opening surface area of parabolic dish, focal length and reflectivity is
calculated.
Concentrator Dish Design:
The surface of opening of a parabolic dish is:
So = (πd2)/4 …………………………………………… (1)
The focal distance is given by the following expression:
f = d2/(16h) ……………………………………………. (2)
h is the depth of the dish.
Mean diameter 62.5 cm
Surface of opening of
parabola
3067.9615 cm2
Depth of the Dish 5 cm
Focal Distance, f 48.82 cm
Practical value of Focal
Distance
53 cm
Fig. 8: Parameters of concentrator dish
Steam Engine: An oscillating cylinder steam engine is a simple
steam-engine design that requires no valve gear. As shown in below
fig-9, the engine construction allows the piston to oscillate in order to
easily direct steam in or out of the cylinder. They have the advantage
of simplicity and, therefore, low manufacturing costs. They also tend
to be more compact than other types of cylinder of the same capacity.
Fig. 9: Hardware components
ISBN-13: 978-1537584836
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Proceedings of ICAER-2016
©IAETSD 201681

4. Boiler: A closed vessel filled with water, which is used to
generate steam by applying heat energy. The Boiler in our model has
a capacity of 1 litre. It is coated with black paint in order to
effectively absorb the concentrated solar radiations as shown in fig-9.
The boiler has two pressure valves viz high pressure valve and low
pressure valve. It has an inlet and outlet for water supply and a hose
is connected from it to the displacer piston of the steam engine.
3. RESULTS
Concentrated Solar Power Technologies are primarily used for
heating applications. But, actually CSP Technology has huge
potential and can be used for electricity generation with good returns
and better efficiency. Among all the Concentrated Solar Power
Technologies, Solar dish – steam engine systems are the most
feasible one.
Fig. 10: Temperature vs time plot.
The above graph plot (Fig 10) shows the temperatures at the dish
surface and at its focal point.
Fig. 10: Temperature vs voltage vs time plot.
Above graph (Fig 10) is plotted by taking temperature
which is formed at the focal point of the parabolic dish
concentrator at x-axis(C) and in y-axis time and voltage (V).
4. CONCLUSION
In this paper, concentrating solar-steam engine system which
utilizes the solar energy for electrical power generation is
modeled. In this model, a generated output of 9V at no-load and
5.3V at loaded condition is achieved. The loads utilized for our
model demonstration are lighting load (LED bulb) and multi-pin
mobile charging. This model was proposed to show that stand-
alone CSP systems can be implemented with a decent generated
output.
This technology is highly suitable for rural electrification
because of its simplicity and modular design, also it is easy to
implement. The setup being modular and standalone, it is
suitable for electrification of organizations, cottage industries etc.
This technology find application in large scale technologies in
industrial and commercial heating . It can also be implemented
for cooling and refrigeration purposes in industrial scale.
ACKNOWLEDGEMENT
1. The author wish to thank the authorities RGIT for providing
the facilities. The encouragement of Principal RGIT gratefully
acknowledged.
References
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ISBN-13: 978-1537584836
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Proceedings of ICAER-2016
©IAETSD 201682

5. [6] Vanita Thakkar, Ankush Doshi, Akshay kumar Rana,
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Asma Anjum received her bachelor’s degree from Visvesvaraya
Technological University, Electrical and Electronics Engineering
in RGIT in year 2016, Bangalore 560-032
ISBN-13: 978-1537584836
www.iaetsd.in
Proceedings of ICAER-2016
©IAETSD 201683