Low cost solar steam generation

LOW-COST CONCENTRATING SOLAR COLLECTOR FOR
STEAM GENERATION
A PROJECT REPORT
Submitted in partial fulfillment for the award of the degree of
BACHELOR OF TECHNOLOGY
in
MECHANICAL WITH SPECIALIZATION IN ENERGY
ENGINEERING
by
ANSHUL BHUPEN DESAI (11BEM0029)
M. SYRIL THOMAS (11BEM0048)
RAGHAV AGARWAL (11BEM0028)
Under the Supervision of
Prof Y. RAJA SEKHAR
School of Mechanical and Building Sciences
VIT
U N I V E R S I T Y
(Estd. u/s 3 of UGC Act 1956)
MAY 2015

i
DECLARATION BY THE CANDIDATE
We hereby declare that the project report entitled “LOW-COST
CONCENTRATING SOLAR COLLECTOR FOR STEAM
GENERATION” submitted by us to Vellore Institute of Technology, Vellore in
partial fulfillment of the requirement for the award of the degree of B.TECH in
Mechanical with specialization in Energy Engineering is a record of bona
fide project work carried out by us under the guidance of Prof Y. Raja Sekhar.
We further declare that the work reported in this project has not been submitted
and will not be submitted, either in part or in full, for the award of any other
degree or diploma in this institute or any other institute or university.
Place: Vellore Signature of the Candidates
Date:

ii
VIT
U N I V E R S I T Y
(Estd. u/s 3 of UGC Act 1956)
School of Mechanical and Building Sciences (SMBS)
CERTIFICATE
This is to certify that the project report entitled “LOW-COST
CONCENTRATING SOLAR COLLECTOR FOR STEAM
GENERATION” submitted by ANSHUL BHUPEN DESAI (11BEM0029),
M. SYRIL THOMAS (11BEM0048) and RAGHAV AGARWAL
(11BEM0028) to Vellore Institute of Technology University, Vellore, in partial
fulfillment of the requirement for the award of the degree of B.Tech. In
Mechanical with Specialization in Energy, Engineering is a record of bona fide
work carried out by him/her under my guidance. The project fulfills the
requirements as per the regulations of this Institute and in my opinion meets the
necessary standards for submission. The contents of this report have not been
submitted and will not be submitted either in part or in full, for the award of any
other degree or diploma, and the same is certified.
Guide Dean, SMBS
External Examiner

iii
ACKNOWLEDGEMENT
Firstly, we would like to thank our internal Guide and Faculty Advisor, Prof. Y.
Raja Sekhar for his unconditional support and guidance throughout the course of
the project. Prof Y.Raja Sekhar was always responsive and his availability in
spite his busy schedule was truly appreciated. We would also like to thank our
Program Manager, Prof. Thundil Karuppa Raj for giving us this opportunity.
Last but not the least, we would like to thank all the reviewers, associated
Faculty Members and lab technicians for their relentless help in the completion
of this project
Place: Vellore
(Anshul Bhupen Desai)
(M. Syril Thomas)
(Raghav Agarwal)
Date:

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TABLE OF CONTENTS
3.8 Project Demonstration 18
3.9 Cost Analysis 22
4 Results and Discussions 25-28
4.1 Results 25
4.2 Performance Metrics 27
CHAPTER
NO.
TITLE PAGE NO.
ABSTRACT vi
LIST OF TABLES vii
LIST OF FIGURES vii
NOMENCLATURE viii
1 Introduction 1-4
1.1 Background 1
1.2 Motivation 1
1.3 Objective 2
2 Literature Survey 5 - 7
3 Design of the System 8 - 24
3.1 Engineering Standards
3.2 Design Constraints
3.2.1 Economic
3.2.2 Environmental
3.2.3 Social
3.3 Trade-offs
8
9
9
9
10
10
3.4 Design Analysis 11
3.5 Technical Specifications 12
3.6 Design Calculation 14
3.7 Implementation of the system 17-18
3.7.1 Concept 17
3.7.2 Fabrication 17

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4.2.1 Economic Design 27
4.2.2 Environment-Friendly Machine 28
5 Conclusion and Future work 29-33
5.1 Conclusion 29
5.2 Cost comparison between existing and proposed
model
31
5.3 Future Work 32
References 34-35
APPENDIX 36 - 46
Appendix 1: Codes 36-40
Appendix 2: Medical Sterilization Using Steam 41-42
Appendix 3: Light Dependent Resistors 43
Appendix 4: Photographs of Project 44-45
Appendix 5 GANNT Chart 46

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ABSTRACT
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.
Concentrating Solar Collectors are widely used for harnessing the Sun’s energy to create
Solar Power. A step in this process is the generation of steam that can be used to produce
electricity or used directly for other applications. However, for personal use and small-scale
utilization, the cost of such collectors is mostly beyond the scope of the common man.
Existing concentrators neglect the use of Fresnel lenses that have extremely high
concentrating properties. This is typically due to high costs of glass lenses and short lifetimes
of plastic lenses. However, rectangular PVC lenses overcome these problems and can be used
to make low-cost, small-scale collectors. In this project, the scope of building an economic
solar collector for small-scale application using Fresnel lens as the concentrator is explored.
An array of three Fresnel lenses along with an efficient tracking mechanism best serves the
purpose of this project. Sufficient steam can be generated by just focusing rays onto a copper
tube, which has excellent heat conductivity properties. This steam can be passed into a
medical sterilizer and used to heat medical apparatus. The technical specification of each
component is explained in detail ahead.
By and large, concentrating solar power (CSP) is a very efficient way of using solar
renewable energy and using it optimally requires a simple tracking mechanism. Using lenses
of the lowest possible size without compromising on power could reduce the cost aspect of
the whole project. This would mean that first we need to calculate the required energy for
medical sterilization, and then calculate the total radiant energy is falling on a tilted plate per
square meter. From these two values, we can calculate the exact area required. It is advisable
to take an area little larger than required to account for various losses.

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LIST OF TABLES
Table No. Title Page No.
Table no 3.1 Summary of components with quantity and
description
13
Table no 4.1
Table no 4.2
Table no 4.3
Variation in the temperature and rate of steam
generated
Variation in the movement of the tracking
mechanism
Difference in cost of the existing and proposed
model
26
27
27
LIST OF FIGURES
Figure No. Title Page No.
Fig. 1.1 Focusing Mechanism of a Fresnel Lens 3
Fig. 1.2 Explanation of Light Deviation inside a Fresnel Lens 4
Fig 3.1 Line Diagram of Project Setup 8
Fig. 3.2 Ray Diagram of a Simple Fresnel Lens 11
Fig. 3.3
Fig 3.4
Fig 3.5
Fig 3.6
Fig 3.7
Fig 3.8
Fig 4.1
Fig. A3.1
Fig. A4.1
Constructing the Base of the Frame
Frame with Copper Tube Welded
Entire Mechanical Setup
Steam Release -1
LCD displaying values of three LDRs
Water Feedback Mechanism
Steam Release through T-Section
Light-Dependent Resistors
Initial Experimentation for Project
18
19
20
21
21
22
25
43
44
Fig. A4.2 Testing of Tracking Mechanism 44
Fig. A4.3 Frame in Initial Phases of Development 45
Fig A5.1 Schedule and Milestone Layout 46

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NOMENCLATURE
Symbol
𝑎 Constant (monthly average of daily global radiation)
𝑏 Constant (monthly average of daily global radiation)
𝐶 𝑝 Specific Heat Capacity (J/kg-K)
𝐻 Radiation falling on the collector surface (kW/m2
)
𝐼𝑠𝑐 Constant (incident radiation)
𝑚̇ Mass flow rate (kg/s)
𝑛 No of days since January 1st
R Reflectivity
𝑆 Sunshine hours
𝑆 𝑚𝑎𝑥 Maximum Sunshine hours
𝑆̅ Average Sunshine hours
Δ𝑇 Temperature Difference (Degrees Celsius)
Greek Letters
𝛿 Declination Angle (Degrees)
𝜃 Incidence Angle (Degrees)
𝜙 Latitude (Degrees)
𝛽 Tilt Angle (Degrees)
𝛾 Surface Azimuth Angle (Degrees)
𝜔 Hour angle (Radians)
Subscripts
b Beam Radiation
d Diffuse Radiation
g Monthly average of daily global radiation
t Daily radiation on a tilted surface
s Hour angle ( Degree)
st Hour angle for a tilted plate (Degree)

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CHAPTER - I
INTRODUCTION
1.1 BACKGROUND
Sun is the primary source of all energy sources. It is one source that can provide continuous
good quality energy radiations. The rise of renewable energy usage is primarily because of
this reliable source. Solar energy can be used in a variety of forms, directly or indirectly, and
for innumerable reasons starting from very basic processes like photosynthesis to complex
energy conversions to burning uranium to creating mass destruction bombs. The list goes on
and on.
Along with the sun, water is one great human necessity. Not only for the body to function but
to sustain mankind on planet Earth. The position of the sun and the availability of water make
our planet habitable. These two elements are used in an enormous array of combinations to
make life easier. Evaporation and condensation are the bases of all these activities. Our
project uses the concept of evaporation in a slightly modified manner.
1.2 MOTIVATION
Water is heated for a number of reasons and used either as hot water or steam. Steam is
formed when water is heated at 100 degree Celsius and is preferred over liquid water at 100
degree Celsius for heat application as it consists of latent heat also. Latent heat is defined as
the additional heat required to convert liquid water into gaseous vapor. Water can be heated
using a number of sources, like fossil fuels, but the high specific heat capacity makes the
boiling of water a cumbersome task. To get rid of these highly expensive and environmental
denting energy sources, we can use solar energy to heat water and form steam.
Although solar heat is a slow method of water heating, adding an array of lenses could make
this process one of the fastest ways. Moreover, using solar energy is free and is not associated
with pollution of any sort. A number of lenses can be used, but the use of Fresnel lenses that
concentrate sunlight violently is most effective and cost efficient. Thus, concentrated solar
energy focused at a limited zone can cause severe heating and intense steam formation.

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1.3 OBJECTIVE
The objective was to develop the concept of generating steam in a short span from solar
energy. This steam could be used in a number of applications like thermal power plants,
industrial cleaning, cooking, wood treatment, etc. Our targeted use for the steam is slightly
different. We are using steam for the sterilization of medical equipment. Medical apparatus
normally has to be sterilized in outdoor facilities and then brought into hospitals and kept in
UV chambers. It does not sound like a hectic process but transporting these equipments
multiple times in a day becomes unnecessary and laborious, especially when the same heat
required for the process can be generated at one of the higher floors of a hospital using solar
energy. Furthermore, it is observed that the effectiveness of sterilization reduces during the
transport phase from outside facilities to the hospital.
The primary aim is to develop the cheapest possible Solar Collector to generate steam with
sufficient efficiency for small-scale application. The possibility of replacing the conventional
concentrators with Fresnel lens is explored to minimize cost while maintaining efficiency.
Fresnel lenses are readily available (found in old television sets) and have extremely high
concentrating powers. For example, a 30cm x 30cm lens can burn paper within a few seconds.
This is a more than handy replacement for expensive glass lenses.
This method seems simple, but it has its difficulties and challenges. The primary one being
the tracking of the solar collector according to the movement of the sun to focus the sun’s
rays as the lenses need to face the sun directly at all times. To counter this challenge, we have
added a tracking mechanism using a light dependent resistor (LDR) and gear motors with
position sensors. Another trouble could be choosing the frame material as the steam generated
would have an impact on the material of the frame as it is exposed to the atmosphere. For
example, wood is highly affected with moisture and loses its stability in adversely moist
conditions. That is why we have chosen galvanized iron as the material that is inert to
moisture and steam.

3
Figure 1.1 Focusing mechanism of a Fresnel lens
Figure 1.1 shows how a Fresnel lens focuses light and this is the principle the project is based
upon. The setup is simple. There will be an iron frame consisting of 3 Fresnel lenses arranged
in a linear manner that will focus the sun's rays onto a copper tube carrying the water. Water
will pass through a pump and an inlet valve that will regulate the flow rate. Once the water
enters the tube, each of the lenses will focus concentrated rays at three points along the length
of the tube that is sufficient to heat the water to generate steam. This steam so generated will
pass through an outlet valve and a nozzle to a chamber containing the medical instruments in
a perforated tray. The chamber will be more vertical than horizontal to prevent the steam from
dissipating. The frame will be attached with three light dependent resistors with a position
sensor that will determine the maximum intensity is falling and turn the lens accordingly.
Gear motors are used to turn slowly the lens as they are more receptive to a small amount of
position changes. The entire tracking mechanism is programmed onto a simple
microcontroller board.
Most of the conditions considered are for equatorial regions like India, where there is
continuous solar radiation. A few mechanisms for cloudy days have been considered.
Standards used for the experimentation of the above prototype have been mentioned. The
entire setup is cost effective with a detailed chart showing the cost comparison compared to
conventional methods.

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To conclude the introduction, we would like to highlight the fact that the basic aim of this
prototype is to generate steam to sterilize medical instruments using steam produced from
solar energy that is cheap, renewable and non-polluting. Moreover, the use of Fresnel lenses
makes it very cost effective, and each of the components used are very easily available,
making the construction very simple. The primary objective is to provide low-cost
sterilization equipment to hospitals so that they can set up a self-sustaining sterilization
process and not depend on outsourcing for the same.
Figure 1.2 further explains how a Fresnel Lens accomplishes concentration of light by
deviation through concentric circular grooves. The entire experiment is explained in detail
with technical specifications throughout the report.
Figure1.2 Explanation of light deviation inside a Fresnel lens

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CHAPTER - II
LITERATURE SURVEY
Solar Energy is a vast and probably endless field of study. Ever since it has become known
that the Sun’s energy can be harnessed gainfully to aid everyday life, solar collectors have
been a field of study, and a lot of theoretical and experimental work on solar collectors has
been carried out till date. The following is a review of the research that has been completed on
the applications of solar energy and the developments in the field of solar collectors. This
thesis derives from all the research mentioned in this review. C. Cordy et al (1995) presented
the design of a low-cost cradle for mounting solar energy concentrator dishes. A strong cradle
provided unobstructed space to mount a well-braced dish which could survive high winds
without being driven to a stow position. The axes of rotation of the dish passed near the plane
of the edge of the dish to reduce wind-induced torques in the drive system. Large radius
tracks were attached to both the dish and the cradle so that the gear train on the drive motors
could be simple and inexpensive. Steve Ruby et al (2010) demonstrated the use of solar
collectors that produced high temperature process heat for industrial use. The system was
designed to produce 300 pounds per square inch (20 bar) pressure steam for a Frito‐ Lay®
Inc. snack foods plant, offsetting natural gas usage by conventional fired boilers, during peak
summer days by approximately 20 percent. A cost‐ effective and reliable source of high
grade heat to reduce the environmental impact of the plant, and improve the reliability of the
local natural gas delivery system by reducing peak demand was developed.
Lifang Li et al (2011) used Finite Element Analysis and laboratory experiments to
present a new concept for designing and fabricating large parabolic dish mirrors which
needed to be relatively precise but were otherwise very expensive to fabricate and transport.
An analytical model to optimize the shape and thickness of the petals was presented for the
parabolic dish mirror I the form of several optimal-shaped thin flat metal petals with highly
reflective surfaces. It was suggested to attach to the rear surface of the mirror petals, several
thin layers whose shapes would be optimized to have reflective petals form into a parabola
when their ends were pulled toward each other by cables or rods. Ibrahim Ladan
Mohammed (2012) used a linear actuator (Superjack) to track the sun, eliminating the need
for constant monitoring by a human operator thereby reducing the cost of labor. For effective
performance the design required that the solar water heater track the sun continuously, and an

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automatic electronic control circuit was designed and developed for this purpose- consisting
of a hydraulic arm, an electric motor, and solar photo sensors circuit.
Roland Winston et al (2012) created and tested many different external compound parabolic
concentrator configurations and by improving the reflector technology and incorporating a
new evacuated thermal absorber design created a collector which operated with a solar
thermal efficiency of 50% at a temperature of 400°F and could be readily manufactured at a
cost of $15 ‐ $18 per square foot. The external compound parabolic concentrator consisted of
a series of stationary evacuated solar thermal absorbers paired with external non‐ imaging
reflectors. The design consisted of a set of parallel cylindrical absorbers, each of them placed
in the center of an evacuated glass tube and each absorber thermally connected to a manifold
using a U tube and each glass tube surrounded by a non‐ imaging reflector made of Alanod
aluminum. The external compound parabolic concentrator design allowed for low‐ cost mass
production, because all components were mass produced and available at very low prices.
A.M Funde et al (2013) explained that Fresnel lenses of imaging and non imaging designs
were one of the best options for solar energy concentration. Compared with imaging systems,
non-imaging systems had the merits of larger acceptance angles, higher concentration ratios
with less volume and shorter focal length, higher optical efficiency, etc. Therefore, non
imaging design could offer the possibilities needed for a breakthrough of Fresnel lenses in
commercial solar energy concentration, both in photovoltaic and thermal power conversion.
Fresnel lens solar concentrators continue to fulfil a market requirement as a system
component in high volume cost effective Concentrating Photovoltaic (CPV) electricity
generation as well as steam generation. The possible applicability of Fresnel lens based
concentrators for application in low pressure steam generation was recommended. Eltahir
Ahmed Mohamed (2013) studied a simple parabolic trough solar collector and tested it under
the local climatic condition. A small scale parabolic trough was fabricated with the local
available materials using stainless steel sheets as parabolic reflector and galvanized steel pipe
as the receiver. Simple parabolic equations were used for the design. It was tested outdoors
and oriented East-West to avoid tracking process. The heat transfer fluid (water) was naturally
circulated from a header tank. From the experiments, the temperature of the heat transfer fluid
had become steady after 82 percent of the total rough length and from the test result and the
collector’s performance, the model was seen fairly acceptable for thermal processes. Physical
output indicated that by using envelope evacuated glass, high quality steam could be
produced for efficient electricity generation.

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Luis E. Juanicó et al (2013) carried out thermal-hydraulic analysis on a large-diameter
plastic hose to hydraulically optimize its design, and developed an innovative solar collector
based on a long plastic hose thatwa connected directly in series from the district water grid to
consumption taking advantage of plastic tubing to develop a simple self-construction collector
costing about 70 dollars for a one-family unit. The design, using new plastic and tubing
technologies, created a simple, low-cost, home-made solar collector and to balance the
efficiency utilized the water-pond design and cylindrical shape which allow the collector to be
placed at a non-optimal angle. Robbie McNaughton et al (2014) performed a detailed
investigation into steam generation using solar thermal technology. The project was broken
into 4 streams of research ensuring a complete system analysis could be undertaken. The first
stream was focused on the development and demonstration of steam receivers suitable for
current turbine technology and advanced supercritical turbines. The second stream looked at
specific applications of superheating steam receivers to address whether solar thermal systems
could be improved by innovative hybridisation with other thermal heat sources. The third
stream was focused on the development of modelling tools to guide the experimental
programs and the fourth stream looked at how high temperature steam could be generated
using a unique thermal storage system. Vinod Parashar et al (2014) conducted performance
tests on a parabolic trough by measurements of total direct radiation on the plane of the
collector, ambient temperature, wind speed, water flow rate, and inlet and outlet temperatures
of the water inside the absorber tube, and presented modifications in the design of solar
parabolic troughs to reduce cost through thermodynamic efficiency improvements by research
and development, scaling up of the unit size, and mass production of the equipment. Stainless
steel sheet was used as a reflector to reduce the cost and improve the life of the reflector.

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CHAPTER – III
DESIGN OF THE SYSTEM
In the design of the present project as shown in Fig 3.1, standards and codes that comply with
the ASHRAE E772 Standards are used as mentioned below.
Figure 3.1 Line diagram of the project setup
3.1 ENGINEERING STANDARDS
1. E772 Terminology of Solar Energy Conversion.
2. G197 Standard Table for Reference Solar Spectral Distributions: Direct and
Diffuse on 20° Tilted and Vertical Surfaces. ( All solar thermal experiments must
be performed with Air Mass Unit being 1.5 which in equatorial regions is between
09:00hrs am 15:30 hours )
3. E905 Standard Test Method for Determining Thermal Performance of Tracking
Concentrating Solar Collectors. ( All Measurement devices must be placed at an
angle of 15 degrees or of the top plate of collector , whichever is lesser )

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The main ones are the three mentioned in the above section. To be precise, the first
standard explains the terms used with its definition. The second one explains that
all solar thermal applications in equatorial regions should be performed with Air
Mass Unit to be a maximum of 1.5. Lastly, the third standard defines the angle at
which solar radiation readings to be taken.
3.2 DESIGN CONSTRAINTS
3.2.1 ECONOMIC
1. Frame
The structure is used for mounting the Fresnel lenses (array of 3 lenses).
The lenses are made of PVC material that reduces the cost of the setup and is durable.
The frame’s base material is iron that is easily available, sturdy and cost effective.
2. Tracking Mechanism
A cheap solar tracking mechanism is made using servo motors and photo resistors for
tracking the sun’s rays.
3. Concentrator Mechanism
The use of Fresnel lens as concentrator ensures that there is no need for any separate
concentrator unlike parabolic dish.
4. Copper Tube
Use of copper tubes as an absorber to minimize heat loss preserves heat and saves
money for another mechanism to tackle heat losses.
5. Pumping Mechanism
Simple and efficient mechanism using pump and valves to control the rate of water
and steam flow is used.
3.2.2 ENVIRONMENTAL
1. The Solar collector uses the energy of the Sun to produce solar power that is
completely pollution free.
2. The use of Fresnel lens as the concentrator ensures that there is no need to
manufacture a concentrating dish. Hence negligible pollution occurs in making
the concentrator.

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3. The steam generated is used for various purposes like cooking, electricity,
heating etc., which reduces dependence on fossil fuels, thereby curbing pollution.
3.2.3 SOCIAL
1. The development of a low-cost steam producing machine which derives all of its
energy from the Sun makes it possible for infirmaries and hospitals in even the
poorest areas to have a means to sterilize soiled medical equipment, thereby
promoting hygiene and preventing the spread of infections.
2. An economical solar collector in households has various implications. This
collector aims to provide poor households and rural households with a means to
lead a healthy life by providing them a way to go about daily chores without
depending on electricity, gas or fossil fuels.
3.3 TRADE-OFFS
1. Efficiency for Cost
 To cut costs, some part of the efficiency had to be sacrificed. Two options were
considered: Reducing dimensions and using cheaper material to preserve efficiency as
much a possible or changing the design altogether.
 It was decided that a middle path between the two options be found. Therefore, a new
design was conceived and the conventional parabolic trough collector was replaced by an
array of Fresnel Lenses made of Poly Vinyl Chloride.
 Fresnel Lenses are cheap and concentrate sunlight violently, resulting in intense
temperatures at the spot of concentration.
2. Environmental Benefit for Reliability
 Concentrating Solar Collectors are efficient only during 9 months in a year because of the
Indian tropical climate.
 However, it is a low price to pay, especially when alternatives are present for the
remaining 3 months, for the benefit of Mother Nature

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3.4 DESIGN ANALYSIS
Figure 3.2 Ray diagram of a simple Fresnel lens
3.4.1 Experimental Setup
An array of three Fresnel lenses (of refractive index 1.52 – 1.54) arranged in a rectangular
matrix of 3 x 1 is placed in an iron frame. The frame is so designed that it boasts about
moving in both the X and Y axis. There are three Fresnel lenses that can be adjusted to
consider a minor alteration in the sun’s motion. This setup is sufficient to attain a
concentrated band of solar rays that can be focused as per requirements.
The next step is to focus it onto a Copper tube. The capacity of the tube is around 100 ml.
Water from the storage tank is passed onto the tube using a pump. This pumping mechanism
is collaborated with the opening and closing of the inlet and outlet valves respectively.
Once water is passed into the tube, highly focused solar beams heat it until it forms steam.
This steam generated is released from a narrow nozzle opening. The steam so generated can
be passed through a regulator for applications such as medical instrument sterilization or
through a turbine and generator for electricity and other such purposes.
The entire frame along with the Fresnel lenses moves according to the sun’s motion. This is
achieved by introducing a tracking mechanism. It consists of three Light-Dependent Resistors
(LDRs), two gear motors, a position sensor and a microcontroller that has a code dumped
onto it. LDRs work on a simple mechanism. When there is a lot of light intensity falling on it,

12
the inbuilt variable resistor reduces the resistance and allows current to pass through the
circuit. This current drives the gear motor towards the direction of sunlight. Similarly, when
there is less light intensity falling on the LDRs, the resistance value increases thus reducing
the current flow and, therefore, the program so designed reverses the motion of the motors.
This simple tracking mechanism is attached with a position sensor that connects the LDRs to
the gear motor. The cost of these components is very minimal which is explained later.
Moreover, all the components are locally available and can be instantly assembled when
required. Another cost saving aspect is the lack of transportation for movement of individual
components. Thus along with cost, much time can also be saved
3.5 TECHNICAL SPECIFICATIONS
DIMENSIONS
1. Fresnel lens (Rectangular)
 180mm x 260 mm
2. Frame (Galvanized Iron - Cuboidal)
 Length – 620 mm
 Breadth – 300 mm
 Height – 300 mm
3. Copper Pipe
 Diameter- 6 mm
 Total length – 1066 mm
 Liquid capacity – 100 mL
4. Valve regulated pump
 Inlet valve
 Outlet valve
5. Storage tank – 1000 mL
 Plastic ( A simple bucket is sufficient )
 Lid ( Plastic )
 Light Dependent Resistor ( LDR )
 Microcontroller
 Gear Motor ( 10 RPM) – 1

13
 Motor Sensor ( LM 293D ) – 2
 Position Sensor – 1
 Regular Sensors – 2
 Helical Gear
A summary of the specifications used for different components in the setup is presented
in Table 3.1 below.
Table 3.1 Summary of components with quantity and description
Sr. No. Name of Component Description/ Utility of the Component Quantity
(or Size)
1. Iron Frame The iron frame is used to mount the whole
apparatus to make it rigid and steady. It helps to
give the external support.
1 No.
2. Centre Shaft The center shaft is used to rotate the lens frame so
that gears can be mounted which can be further
connected to the motor for tracking purpose.
It is a part used to transfer energy input from the
motor to the frame.
1 No.
3. Microcontroller + Kit The microcontroller is used to code the tracking
mechanism using simple logic using C or C++
Language. The microcontroller helps in the motor
speed regulation and helps in the tracking
mechanism.
1 No.
4. Helical Gear A Helical gear is connected to the motor so that
when the gear moves the frame also moves and
hence tracking can be obtained using the input
from the motor that is regulated using
microcontrollers.
1 No.
5. Spur Gear A spur gear is paired to the helical gear that is
coupled with the motor.
1 No.
6. Power Supply It is used to run the motor of the required rpm. 1 No.
7. Power Cord Used to connect the power supply to the motors for
powering the tracking mechanism
1 No.
8. Power Box Fix It is the component where the power can be
regulated using a switch mechanism.
1 No.
9. Motor 10 rpm It is the triggering component for the shaft to rotate
when the sensors do the tracking of the sun.
1 No.
10. LM 293D – Motor
Forward Backward
This motor driver IC can simultaneously control
two small motors in either direction; forward and
reverse.
1 No.
11. Photo Sensors + Position
Sensor
LDR Sensors are used so that the incident light
radiation can be used to sense the light and the
whole apparatus can be tracked using this
mechanism
3 Nos.

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3.6 DESIGN CALCULATIONS
3.6.1 STEPS
The following steps are followed in the design calculations of the components.
1. Calculate the energy falling on the lenses
2. Calculate the steam required
3. Calculate the area of the collector required
A. Calculation of the energy falling on the lenses
1. Calculating Declination Angle
Declination(d) = 23.45sin((360 /365)(284+n))
n = 31+28+31+30+15 =135
Declination(d) = 23.45sin((360 /365)(284+135))
Declination(d) =18.79°
2. Calculating Angle of Incidence
cosq = 0 = cosjcosdcosw +sindsinj
Calculating hour angle
w = cos-1
(-tandtanj)
w = 94.416°
3. Daily extra-terrestrial radiation
H0 = 24
p *Isc *3600[1+(0.33cos(360+ n) / 365)](wsinjsind +cosj cosdsinw)
H0 = 24
p *1.367*3600[0.97743](0.47623)
H0 = 38165.706kJ / (m2
- day)
H0 = 0.44173kW / m2
4. Monthly average of daily global radiation
Hg
H0
= a +b(
S
Smax
)
Hg
H0
= 0.30 +0.44(
10
12.58
)
Hg = 0.2870kW / m2

15
5. Monthly average of daily diffuse radiation
Hd
Hg
=1.411-1.696(
Hg
H0
)
Hd = 0.0887kW / m2
6. Calculating Reflectivity
a) Calculating tilt angle
b = 0.9j
b = 0.9*12.92
b =11.628°
b) Calculating hour angle for a tilted slope
coswst = -tand tan(j - b)
coswst = -tan18.79°tan(1.292)
coswst = 90.439°
c) Calculating beam radiation reflectivity
Rb = (sindsin(j - b)+cosd coswst cos(j - b)) / (sindsinj)+(cosj cosd cosws )
Rb = (sin18.79sin(1.292)+cos(18.79)cos(90.439)cos(1.292)) /
(sin(12.92)sin(18.79))+(cos(12.92)cos(18.79)cos(94.416))
Rb = 0.9189
d) Calculating Diffuse Radiation Reflectivity
Rd = (1+cosb)/ 2
Rd = 0.9897
7. Calculating Daily radiation on a tilted surface
2
/53387.0
3057.02880.0
*)(*)1(
mkWH
H
RR
H
H
R
H
H
H
H
t
t
rd
g
d
b
g
d
g
t




16
B. Calculating the steam required
1. Calculating mass flow rate
Density = mass / volume
Density of steam at 105 degree Celsius = 0.590 kg / 𝑚3
Mass (m) = density * volume
Mass (m) = 0.590 * 0.001
m = 0.589 * 10-3
kg
So, we need the amount mentioned above of steam per second to maintain a steady flow
of steam for 4 minutes.
Therefore,
Mass flow rate =0.589 * 10-3 kg/s
2. Calculating Specific Heat Capacity
CP at 100°C → 4216 J/KgK
CP at 120°C → 4250 J/KgK
CP at 140°C → 4283 J/KgK
𝐂 𝐏 𝐚𝐭 𝟏𝟑𝟐°𝐂 → 𝟒𝟐𝟔𝟗 𝐉/𝐊𝐠𝐊
3. Calculating difference in Temperature
∆ 𝑇 = 132 − 100 = 32°𝐶
4. Calculating Total Steam Required
𝐒𝐭𝐞𝐚𝐦 𝐑𝐞𝐪𝐮𝐢𝐫𝐞𝐝 = 𝒎̇ 𝑪 𝒑∆𝑻
Steam Required = 0.589 ∗ 10−3
∗ 4269 ∗ 100
Steam Required = 251.44 W
C. Calculating the area of the collector required
𝑻𝒐𝒕𝒂𝒍 𝑬𝒏𝒆𝒓𝒈𝒚 𝒇𝒂𝒍𝒍𝒊𝒏𝒈 = 𝑺𝒐𝒍𝒂𝒓 𝑹𝒂𝒅𝒊𝒂𝒕𝒊𝒐𝒏 ∗ 𝑨𝒓𝒆𝒂 𝒐𝒇 𝒍𝒆𝒏𝒔
251.44 = 534.396 ∗ 𝐴𝑟𝑒𝑎 𝑜𝑓 𝑙𝑒𝑛𝑠
𝑨𝒓𝒆𝒂 𝒐𝒇 𝒍𝒆𝒏𝒔 = 𝟎. 𝟒𝟓 𝒎 𝟐

17
3.7 IMPLEMENTATION OF THE SYSTEM
3.7.1 Concept
We decided to take a backward approach. Our project is based on steam generation for
medical sterilization. So first we calculated the amount of steam required for the sterilization
process. To calculate this, we needed parameters such as mass flow rate of entering the water,
specific heat capacity at 132 o
C and the required temperature difference. We have taken a
sterilization tank having a volume of 1 liter that needs to be heated for 4 minutes up to 132
degree Celsius. Therefore, the temperature difference required would be 100o
C (ambient
water being at 32 o
C), and mass flow rate can be calculated. By the above-mentioned
parameters, we have calculated the required steam for sterilization. The density of steam at
132 o
C was found using regular steam tables and the volume of steam . Next Step was to
calculate the amount of radiation required to fall on the copper tube that has a diameter of 6
mm. The total volume of the tube will be 100 ml. 2 valves are so placed that enough pressure
is generated to form steam instead of just intangible evaporation. As 3 Fresnel lenses are used,
the intensity of rays will be focused at 3 different points on the length of the evacuated tube.
This will lead to continuous heating and an expected time of around 30 minutes will be
required to generate the required steam. The copper tube will be painted black to enhance the
absorptivity. The third step was the calculation of the total radiation falling per Meter Square
on the lens so that we can calculate the area of the required lenses.
3.7.2 FABRICATION
After the design calculations, it was assessed that 675 kW of heat energy was required. Heat
radiation falling on the lens was calculated to be 500 W/m2
. A 3 lens setup was chosen. Iron
frame of around 300 mm X 950 mm was fabricated with the three lenses attached in a vertical
column. The entire lens setup was placed on a metallic stand. These lenses are made of
polyvinyl chloride (PVC). The lenses focus the radiation to three specific spots across the
length of the Copper tube at a distance of 18 cm from each lens’s center. Continuous constant
spot radiation leads to instant heating of the fluid in the tube. The tube is attached to a low
power pump (medium size head) with 2 valves (made of stainless steel) – one inlet and one
outlet. Steam regulating channels attached to a plastic knob regulates steam flow.

18
The sterilization instruments are kept in a plastic composite with a more vertical than
horizontal shape. This is so done to prevent the steam from diverging and cooling. A
microcontroller was used to link the tracking mechanism. A code was incorporated onto it. 3
medium sized light detecting resistors (LDRs) were used to track the sun’s motion. Based on
the intensity of light falling onto it, the LDRs along with the position sensor move a 10 RPM
gear motor on either side of the frame. This motor is attached to an associated LM293D
motor sensor, thus tracking the sun’s motion.
A rough cost chart was set up. Effectively, the Fresnel lenses would not cost anything as they
can be retrieved from any old cathode ray televisions that are no longer in use. Ours was an
experimental setup in which we have purchased Polyvinyl chloride (PVC) lenses and the
success of this experiment has proved the concept right. Now any old Fresnel lens could be
used. Tracking mechanism required can be used from any old and dysfunctional solar
equipment (because usually tracking mechanism lasts longer than the solar equipment it is
attached to). Pumps, valves, and the storage tank could be recycled from any existing
application as they are sturdy and can be re-used. The entire tracking mechanism has a very
minimal cost (shown in the cost chart). The only cost challenging device is when an
evacuated copper tube is used instead of the copper tube to retain more heat and has to be
maintained very delicately, but this is a one-time investment only.
3.8 PROJECT DEMONSTRATION (PROTOTYPE)
Figure 3.3 Constructing the base of the frame

19
FRAME
A cuboidal steel frame of dimensions 300mm X 950mm was designed. Figure 3.3, above,
shows the iron frame being welded. The top, bottom and side parts of the frame were welded
using Tungsten Inert Gas Welding method and Grinded and cut for fine adjustments.
Aluminum plates were screwed followed by permanent gluing to the side top edges of the
frame. Three Fresnel lenses were slid into the frame under the aluminum plates, and the
complete setup is shown below in Figure 3.4. This makes the lenses easily removable and at
the same time very sturdy. A copper tube with a T-shaped ending was attached to the bottom
half of the frame. The volume of this tube is 100 ml.
Figure 3.4 Frame with copper tube welded
Next, a pump that stays in water at all times was attached to the tube. This pump is connected
to the copper tube by an elastic plastic pipe. This tube is tightened at both ends by strong
metallic ring clips.

20
Figure 3.5 Entire Mechanical setup
Once the entire setup was ready, a tracking mechanism was constructed. This tracking
mechanism consists of a few main elements. 3 Light Detecting Resistors (LDRs), a 10 RPM
gear motor and a helical roller. The helical roller prevents the gear motor from overturning
and reduces the speed for minor adjustments. When the LDR detects light intensity, it shows a
signal on the display attached. Then this microcontroller is connected with one end of the
power supply and one end of the motor. The motor with gear wheel turns based on the signal
provided by the circuit. The entire setup is attached with two sets of wires: one that winds in
one direction when the other unwinds and vice versa. A 12.4 Volt and 1 Ampere battery are
used. Current passes from the battery to the micro-controller and from the controller to the
motor. This motor spins the helical gear that controls the plastic gear wheel. The complete
setup is seen in Figure 3.5 with the tracking mechanism attached, and the steam being
released is shown in Figure 3.6.

21
Figure 3.6 Steam release pipe
The Microcontroller display as seen in Figure 3.7 shows 3 alphabets with light intensity
variations – F, S, R. The forward direction is represented by F, which moves the setup in a
clockwise direction. S is when the light intensity is maximum at the center LDR. R
represents reverse direction, and the frame moves anti–clockwise. This is how the tracking is
done.
Figure 3.7 LCD displaying values of three LDRs

22
FEEDBACK
The storage tank used to pump water is placed under the outlet chamber. Hot water comes out
from down when steam is emitted from the top. The hose attached to the pump can be seen
coming out of the bucket in Figure 3.8. The only precaution is to make sure that the pump is
always under water and at no point is it exposed to the air. This leads to conservation of
water, and the subsequent water heats faster as it is already hotter. Time for heating of the
next batches of water is much faster, but the only problem in this could be the maintenance of
the water pump. This can be avoided by placing the pump in a casing with only the plastic
wire coming out of the casing.
Figure 3.8 Water Feedback Mechanism
3.9 COST ANALYSIS
Proposed Design: Fresnel Lens Solar Collector
a) Parabolic Dish Solar Collectors can be replaced by employing Fresnel Lenses as
the concentrator.
b) Such a collector would have the following characteristics:
 Dimensions: 0.26 m x 0.18 m
 Focal Length: 0.33 m

23
 Total Collector Area: 0.2 m2
 Concentrator: Array of 3 Fresnel Lenses
 Frame and stand: Galvanized Iron
 Receiver: Copper Tube with black paint
 Capacity of steam generation: Mass flow rate of steam at the outlet is 1.5827 x
10-3
kg/s, which gives approximately 2.8 kg of steam in 30 minutes.
c) Cost: Rs. 2500/- (Excluding Tracking Mechanism and Pump)
Total cost is Rs. 5500/- (Including Tracking Mechanism and Pump)
COST BREAKDOWN
PRIMARY CHARGES
1. Collector
Fresnel Lenses: Rs. 500 x 3= Rs. 1500/-
Iron: Rs. 200/-
Copper Tube: Rs. 200/-
Wire: Rs.50/-
Pump: Rs. 500/-
Steel Rods: Rs. 100/-
Beading: Rs. 35/-
Pipe: Rs.60/-
Black Paint: Rs. 200/-
Microcontroller Kit: Rs. 1000/-
Gear Wheels: Rs. 100/-
Power Supply: Rs. 200/-
Power Card: Rs. 50/-
Power Board: Rs. 80/-
10 rpm Motor: Rs. 310/-
LM 293D Motor: Rs 200/-
Sensors: Rs. 200/-

24
SECONDARY CHARGES
 Transportation Charges
 Assembly Costs
 Welding Cost
 Maintenance Cost
 Steam Regulator
These charges remain constant but in this prototype, there is no need for massive
transportation or maintenance cost. Assembly cost is a one-time expenditure. Instead of just
screws bolting the components, we weld it so that there are no falling and repair charges. In
heat applications, it is always advisable to weld the parts. As the size of the entire setup is
considerably small as compared to the conventional configuration, moving the entire structure
is a fuss-less process. Fresnel lens setup is almost half the size of a parabolic or cylindrical
lens setup.

25
CHAPTER-IV
RESULTS AND DISCUSSION
4.1 RESULTS
The Fresnel lens used in the prototype, of dimension 180 mm x 260 mm, concentrates
sunlight at a spot that is at a temperature of 220o
C. 3 such lenses were used, each giving
the same temperature when focused aptly.
The spots are concentrated on the Copper tube that contains water to be converted into
steam, and they heat the tube evenly over the course of the experiment.
The copper tube conducts heat evenly, and transfers it to the water that starts boiling when
it reaches the temperature of 100o
C, after approximately 21 minutes for a volume of
around 100 ml satisfying the requirement as per ASHRAE G-197 Standards for medical
sterilization.
Steam is produced after another 8 – 10 minutes of water starting to boil which is emitted
from the end with a T-section, as shown below in Figure 4.1.
Figure 4.1 Steam Release through T-Section of the pipe

26
The steam generated is slow because of the absence of a constant pressure source that
could be increased using a piston mechanism or syringe push mechanism.
The Tracking Mechanism, which uses Light-Dependent Resistors to track the Sun, moves
the frame periodically in such a manner that the Lenses face the Sun directly at each
instance.
If the tube is filled with already-hot water initially, the process of heat generation is faster.
The water heats maximum up to 4 pm according to the Indian time that is more than
enough for our purpose.
The variation in the temperature and rate of steam generated using the existing setup is
presented in Table 4.1.
Table 4.1 Variation in the temperature and rate of steam generated
Time
(Hrs)
Heat Flux
Temperature at
the flux
Temperature of
the steam
generated
Flow Rate of
steam
(kJ/m2-hour) (oC) (oC) (g/s)
9:30 556.65 225 100.2 0.426
10:30 654.23 240 101.7 0.512
11:30 717.96 250 103.2 0.583
12:30 744.68 250 104.1 0.597
13:30 732.96 250 103.8 0.591
14:30 683.43 240 102.3 0.589
15:30 598.66 230 100.9 0.557
Similarly, the performance of the tracking mechanism with the movement of the sun
during the day is presented in Table 4.2,

27
Table 4.2 Variation in the movement of the tracking mechanism
Time
(Hrs)
Tracking
angle
required
(Degrees)
Measured Angles (Degrees)
Tracking
angle
achieved
(Degrees)
Error
( % )
Day 1 Day 2 Day 3 Day 4 Day 5
9:30 0 0 0 0 0 0 0 0
10:30 15 14 15 14 14.5 14 14.3 -4.6
11:30 30 29 29.5 31 28.5 29 29.4 -2
12:30 45 45.5 45.5 46 46 45 45.6 1.33
13:30 60 59 60.5 59.5 59 60 59.6 -0.66
14:30 75 74 75 73.5 74 74 74.1 -1.2
15:30 90 89 89.5 89.5 88 89 89 -1.11
The cost of steam generation per unit volume is summarized in Table 4.3 and compared
with the existing method of steam generation.
Table 4.3 Difference in cost of the existing and proposed model
Parameter Parabolic Dish collector
(existing)
Fresnel Lens Collector
(proposed)
Time required for steam
generation
30 minutes 30 minutes
Volume of Steam 2 lit @ 1050
C 1.062 lit @ 1050
C
Apprx. Cost per kg of
steam
Rs. 5750/- Rs. 5178/-
4.2 PERFORMANCE METRICS
4.2.1 ECONOMIC DESIGN
The prime driving force behind the project was the ultimate conception of a low-cost Solar
Collector for small-scale applications. To accomplish this goal, the concentrator, traditionally
a parabolic trough made of concentrating material, was replaced by a rectangular Fresnel lens
made of Poly-Vinyl Chloride. The utilization of PVC accomplished two goals:

28
a) It cut down the cost extensively, as PVC is cheap and allows for the fabrication of
Fresnel lens as small rectangles, while retaining the concentrating prowess which is not
easily accomplishable with glass, thereby reducing the weight of the collector and
replacing glass which is costlier.
b) Eliminated the need for frequent replacement, as PVC is durable and does not degrade
easily under direct sunlight.
This turned out to be an efficient and effective cost-cutting measure as the use of Fresnel
lenses is cheaper than using a parabolic trough which is generally made of Aluminium,
glass, mercury and silver. Traditionally Fresnel lenses are large lenses made of glass; the
use of PVC proves to be an adequate substitute and makes the project feasible. Here, the
cost cutting is accomplished while maintaining the efficiency.
4.2.2 ENVIRONMENT-FRIENDLY MACHINE
The foremost objective of any solar energy device is to aid the development of the
unconventional source of energy and turn it into a conventional one, or in simpler terms to use
the energy of the Sun to produce solar power which is completely pollution free. All solar
devices obviously accomplish this primary objective. However, the proposed solar
concentrator not only meets this goal but also eliminates the need to manufacture a
concentrating dish or trough- a process which not only utilizes precious energy but also
requires metals like Mercury and Silver for production which contribute towards waste
generation and need to be mined. Hence, negligible pollution occurs in putting together a
Fresnel lens concentrator. Additionally, the steam generated can be used for various purposes
like sterilization, cooking, and electricity generation that reduces dependence on fossil fuels,
thereby curbing pollution and conserving resources.

29
CHAPTER - V
CONCLUSION AND FUTURE WORK
5.1 CONCLUSION
a) Solar concentrating collectors can be modified to replace the parabolic trough with a
Fresnel lens to increase the intensity with which sunlight is concentrated and also bring
down cost.
b) Fresnel lenses enjoy considerable advantages for use in a solar concentrating collector
over parabolic troughs at a smaller scale:
 They occupy lesser space: an effective parabolic trough unit may take up to 10ft x
3ft of space or more, whereas an effective Fresnel Lens unit may only take up to 2ft
x 3ft of space.
 Though the area of concentration in case of Fresnel lenses is lesser than parabolic
troughs, they make up for it with increased efficiency of concentration: Parabolic
troughs may heat a pipe up to 260o
C, or sometimes more, whereas Fresnel lenses are
capable of superheating a pipe to over 540o
C effectively, depending upon the lens.
 However, Fresnel lenses need more complex tracking mechanisms than parabolic
troughs as they need to be facing direct sun rays at all times to function effectively:
this is factor to be considered because developing the tracking mechanism increases
cost substantially.
 The entire set-up consisting of 3 Fresnel lenses, evacuated tube, cast iron frame,
tracking mechanism using Light-Dependent Resistors, pumps, and valves,
ultimately generates a steady amount of steam at an economic cost as desired.
 The use of Fresnel lens also eliminates the need for manufacturing a solar trough
thereby reducing pressure on fossil fuels and metals.

30
c) At the outset it was expected that 1 Fresnel Lens of A4 size would be sufficient to boil
water equivalent to the quantity of a standard can and generate steam; and this could be
replicated for a correspondingly larger lens and correspondingly higher amount of water.
However, experimentation proved contrary:
 In the above case boiling occurred very slowly and only at the point where the spot
of sunlight was focused. The entire bulk of water had to be heated before efficient
boiling could occur, and this turned out to be an excruciatingly painstaking process
with just one small lens.
 To expedite boiling, either the size of the lens could be increased for the spot of
sunlight to cover the entire length of water, or more lenses could be used for uniform
heating.
 Considering economic and realistic constraints, using an array of 3 lenses instead of
just 1 lens proved to be a better option.
d) The project has many benefits as it develops a mechanism to utilize the Sun’s energy to
produce steam from water that can be used for various purposes such as sterilization,
cooking (by direct steaming or heating the bottoms of vessels), rotating turbines to
generate electricity at a sufficiently lower cost, humidification, treatment of wood and
concrete, and process heat applications.
e) What distinguishes the proposed model from existing solar collectors is that it uses
Fresnel lenses to concentrate sunlight:
 Traditionally Fresnel Lenses have not been successfully used in smaller solar
applications owing to the high cost of spherical glass lenses that cost millions of
dollars and are feasible only for large projects.
 Plastic lenses have been avoided due to their lackluster properties when exposed to
direct sunlight.

31
 Therefore, the popular choice has been to use parabolic troughs, which have
undergone various innovations throughout the years.
f) This model, however, had made use of rectangular Fresnel lenses made of Poly-Vinyl
Chloride which are cheap, unlike glass lenses and which are durable and deteriorate much
slowly than plastic.
g) The project’s aim was to generate steam at 104o
C, a realistic goal that has been achieved.
h) A misgiving of the mechanism is that speed with which steam is generated is not as rapid
as expected and can be improved.
 However, a process like sterilization can still be accomplished by subjecting the
equipment to the steam for a larger amount of time.
 The speed of the steam can also be increased by facilitating faster boiling that can be
ensured by employing external media like pairing the collector with reflective mirrors
or small parabolic dishes.
5.2 COST COMPARISON BETWEEN EXISTING AND PROPOSED MODELS
Inspiration for Proposed Model: Parabolic Dish Solar Collector
a) The Dish type Solar Cooker is the popular choice for solar cooking.
b) Large parabolic dish solar collectors are used for industrial applications to
generate steam and produce electricity. For small-scale applications that involve
the use of dry steam, the dish type solar cooker can be replicated to produce a
Parabolic Dish Solar Collector.
c) Such a collector would have the following characteristics:
 Aperture Diameter: 1.4 m
 Focal length: 0.28 m
 Total Collector Area: 3 m2

32
 Concentrator: Parabolic Dish made of approximately 0.4 mm thick Anodized
Aluminium (75 % reflectivity). For higher reflectivity (90 %), imported
higher-grade material is used.
 Frame and stand: Mild Steel with Epoxy/Anti-Rust Coating
 Receiver: Copper Tube with black paint/enamel coating
 The capacity of steam generation: Power delivered is 0.6 kW that can boil 2
liter of water in 30 minutes by generating a temperature of around 350o
C round
receiver.
d) Cost: Rs. 8500/- for collector with 90% reflectivity (Excluding Tracking
Mechanism and Pump)
Total cost is up to Rs. 11,500/-
As already shown in the cost analysis section, the cost of the entire setup is not more than
Rs. 5500/-. Thus there is a clear saving of at least Rs. 5000. Not only is the cost of
components very less, the components are easily available too. This means there would be
further saving in cost as there will be reduced or almost no transport and storage cost
5.3 SCOPE OF FUTURE WORK
Nothing is perfect, and there always exists scope for improvement and for features to be
added. Moreover, then when a certain something has been improved, there exists greater
scope for improvement still. Innovation is a never-ending process.
a) To improve the efficiency of steam generation and speed with which steam is
generated, the process of heating can be catalysed by adding mirrors to the
apparatus such that a greater intensity of sunlight falls on the evacuated tube to aid
the spot focus of Fresnel lens.
b) The system can be paired with a small parabolic trough that heats the water to
almost boiling state such that when Fresnel lenses concentrate sunlight, the water is
immediately zapped into steam.
c) Even though the collector has been designed to work for the minimum value of
incident solar radiation, it does not function in case of cloud cover. To mitigate this

33
limitation, the apparatus can be connected to PV Cells, which convert and store the
Sun’s energy in the form of electricity. This electricity can be used to generate steam
in case sunlight is absent, via an electrical heating mechanism.
d) The current model employs a rather complex tracking mechanism, using Light-
Dependent Resistors, which accounts for a bulk of the collector’s cost. Research can
be done to develop a simpler and less expensive tracking mechanism.
e) A Solar Pond can be integrated to augment the thermal characteristics of the proposed
model.
.

34
REFERENCES
I. Journal References:
1. Ibrahim Ladan Mohammed, “Design And Development Of A Parabolic Dish Solar Water
Heater”, International Journal of Engineering Research and Applications (IJERA), Vol. 2,
Issue 1, pp. 822-830, Jan-Feb 2012
2. C. Cordy, “A Strong, Low-Cost Mount for Parabolic Dish Solar Collectors”, Journal of
Solar Energy Engineering, Vol. 117, Issue 3, pp. 205-209, August 1995
3. Lifang Li and Steven Dubowsky, “A New Design Approach for Solar Concentrating
Parabolic Dish Based on Optimized Flexible Petals”, Mechanism and Machine Theory,
Vol. 46, Issue 10, pp. 1536-1548, October 2011
4. Luis E. Juanicó and Nicolás Di Lalla, “A New Low-Cost Plastic Solar Collector”, ISRN
Renewable Energy, Vol. 2013, pp. 1-10, 24 July 2013
5. Pankaj D. Menghani, R. R. Udawant, A. M. Funde and Sunil V. Dingare, “Low Pressure
Steam Generation by Solar Energy With Fresnel Lens: A Review”, IOSR Journal of
Mechanical and Civil Engineering (IOSR-JMCE), Vol. 5, Issue , pp. 60-63, 2013
6. Vinod Parashar, Vinod Jat and Swati Chaugaonkar, “Modification in Design of Solar
Parabolic Through”, International Journal of Applied Engineering Research, Vol. 9, Issue
8, pp. 977-984, 2014
II. Books:
1. H.P. Garg and J. Prakash, Solar Energy (Fundamentals and Applications), 1st
Edition,
McGraw Hill Education Private Limited, 1997
2. S.P. Sukhatme and J.K. Nayak, Solar Energy (Principles of Thermal Collection and
Storage), 3rd
Edition, McGraw Hill Education Private Limited, 2014
III. Conference Papers:
1. Eltahir Ahmed Mohamed, “Design And Testing Of A Solar Parabolic Concentrating
Collector”, In proceedings of the 11th
International Conference on Renewable Energies
and Power Quality (ICREPQ ’13), Bilbao, Spain, 20th
-22nd
March 2013
2. Robbie McNaughton, “Advanced Steam Generating Receivers for High-Concentration
Solar”, In proceedings of the Project commissioned by the Australian Renewable Energy
Agency with CSIRO and Abengoa Solar, Newcastle, New South Wales, Australia,
October 2014

35
3. Roland Winston, “Design And Development Of Low‐cost, High‐temperature Solar
Collectors For Mass Production”, In proceedings of the Public Interest Energy Research
Program commissioned by the California Energy Commission, Merced, California, May
2012
4. Steve Ruby, “Industrial Process Steam Generation Using Parabolic Trough Solar
Collection”, In proceedings of the Public Interest Energy Research Program
commissioned by the California Energy Commission, California L.P., Denver, Colorado,
November 2010
IV. URL:
1. https://esc.fsu.edu/documents/DascombJThesis.pdf (9th
December 2014)
2. http://www.lso-inc.com/sterilization-validation-services/iso17665-steam-
sterilization.html (2nd
April 2015)

36
APPENDIX 1
PROGRAMMING CODES
MATLAB CODING
The above calculation is a sample calculation for the solar radiation received by Vellore
(12.9202° N, 79.1333° E) . We have taken the least radiation observed annually calculated by
the below mentioned MATLAB code. The MATLAB coding can be replicated for calculating
changes in radiation for other months and making necessary adjustments.
Clear ;
Clc ;
n=135 ;
L=12.9202 ;
pi=3.14 ;
Isc=1.367 ;
a=0.30 ;
b=0.44 ;
r=0.0513 ;
S=10 ;
d=23.45+sind((360/365)*(284+n)) ;
ws=acosd(-tand(d)*tand(L)) ;
wsr=ws*(pi/180) ;
Smax=(2/15)*ws
Ho=(((1/pi)*Isc)*(1+(0.033*cosd((360*n)/365)))*((wsr*sind(L)*sind(d))+(cosd(L)*cosd(d)*
sind(ws))))*1000;
Hg=Ho*(a+(b*(S/Smax)))
Hd=Hg*(1.411-(1.696*(Hg/Ho)));
beta=0.9*L;
wst=acosd(-tand(d)*tand(L-beta));
wstr=(pi/180)*wst;

37
Rb=((wstr*sind(d)*sind(L-beta))+(cosd(d)*sind(wst)*cosd(L-
beta)))/((wsr*sind(L)*sind(d))+(cosd(L)*cosd(d)*sin(ws)));
Rd=(1+cosd(beta))/2;
Ht=(((1-(Hd/Hg))*Rb)+((Hd/Hg)*Rd))*Hg
CIRCUIT CODING
#define LED PORTB.F0
#define MOTOR_FWD PORTB.F7
#define MOTOR_RVS PORTB.F6
// LCD module connections
sbit LCD_RS at RD2_bit;
sbit LCD_EN at RD3_bit;
sbit LCD_D4 at RD4_bit;
sbit LCD_RS_Direction at TRISD2_bit;
sbit LCD_EN_Direction at TRISD3_bit;
sbit LCD_D4_Direction at TRISD4_bit;
// End LCD module connections
void led_blink(){

38
LED = 1;
Delay_ms(100);
LED = 0;
Delay_ms(400);
}
unsigned int ldr1, ldr2, ldr3;
char buffer[20];
void main(){
CM1CON0 = 0;
CM2CON0 = 0;
CM2CON1 = 0;
ADCON0 = 0b00001111;
ADCON1 = 0;
ANSEL = 0b00001111;
TRISA=0xFF;
TRISB=0b00111110;
TRISC=0XFF;
LED =0;
MOTOR_FWD =0;
MOTOR_RVS =0;
ADC_Init();
Lcd_Init();

39
Lcd_Cmd(_LCD_CLEAR);
Lcd_Cmd(_LCD_CURSOR_OFF);
Lcd_Out(1, 1, "SOLAR VALUE");
led_blink();
led_blink();
MOTOR_FWD = 1;
MOTOR_RVS = 0;
led_blink();
led_blink();
MOTOR_FWD = 0;
MOTOR_RVS = 0;
led_blink();
led_blink();
MOTOR_FWD = 0;
MOTOR_RVS = 1;
Lcd_Cmd(_LCD_CLEAR);
while(1){
ldr1 = ADC_Read(1) / 10;
IntToStr(ldr1, buffer);
Lcd_Out(1, 1, buffer);

40
if(ldr2 > ldr1 && ldr2 > ldr3){
Lcd_Out(1, 10, "S");
MOTOR_FWD = 0;
MOTOR_RVS = 0;
}
else if(ldr1 > ldr3){
Lcd_Out(1, 10, "F");
MOTOR_FWD = 1;
MOTOR_RVS = 0;
}
else{
Lcd_Out(1, 10, "R");
MOTOR_FWD = 0;
MOTOR_RVS = 1;
}
led_blink();
} }

41
APPENDIX 2
STEAM STERILIZATION FOR MEDICAL EQUIPMENT
The basic principle of steam sterilization, as accomplished in an autoclave, is to expose each
item to direct steam contact at the required temperature and pressure for the specified time.
Thus, there are four parameters of steam sterilization: steam, pressure, temperature, and time.
The ideal steam for sterilization is dry saturated steam and entrained water (dryness fraction
≥97%). Pressure serves as a means to obtain the high temperatures necessary to quickly kill
microorganisms. Specific temperatures must be obtained to ensure the microbial activity. The
two common steam-sterilizing temperatures are 121o
C (250o
F) and 132o
C (270o
F). These
temperatures (and other high temperatures) must be maintained for a minimal time to kill
microorganisms. Recognized minimum exposure periods for sterilization of wrapped
healthcare supplies are 30 minutes at 121o
C (250o
F) in a gravity displacement sterilizer or 4
minutes at 132o
C (270o
C) in a pre-vacuum sterilizer. At constant temperatures, sterilization
times vary depending on the type of item (e.g., metal versus rubber, plastic, items with
lumens), whether the item is wrapped or unwrapped, and the sterilizer type.
According to ISO 17665, Steam Sterilization is a simple yet very effective decontamination
method. Sterilization is achieved by exposing products to saturated steam at high
temperatures (121°C to 134°C). Product(s) are placed in a device called the autoclave and
heated through pressurized steam to kill all microorganisms including spores. The device's
exposure time to steam would be anywhere between 3 to 15 minutes, depending on the
generated heat. Sterilized packages need to be allowed to dry before being removed from the
autoclave to prevent contamination. Once removed, they must be allowed to cool to ambient
temperatures, which may take several hours.
For effective sterilization it is critical that the steam covers all surfaces of the device. To
ensure optimal conditions, many autoclaves have built in meters that display temperature and
pressure conditions with respect to time. Biological indicator devices and Indicator tape
which changes color are also used to gauge the performance of the autoclave. The chemical
tape is placed both inside and outside the sterilized packages, whereas bio-indicator devices
release spores inside the autoclave. The spores are incubated for 24 hours at the end of which

42
time their growth rate is measured. If the spores have been destroyed it indicates that the
sterilization process was effective.
ISO 17665 specifies requirements for the development, validation and routine control of a
moist heat sterilization process for medical devices.
ISO 17665 covers sterilization of solid as well as liquid medical devices. According to the
standard it is the manufacturer's responsibility to develop the process and provide guidelines/
instructions for operation and validation of the process. The standard also requires detailed
documentation of all conditions that affect the process performance now and in the future.

43
APPENDIX 3
LIGHT -DEPENDENT RESISTORS
A photo-resistor or light-dependent resistor (LDR) or photocell is a light-controlled
variable resistor. The resistance of a photo-resistor decreases with increasing
incident light intensity; in other words, it exhibits photoconductivity. A photo-resistor is made
of a high resistance semiconductor. In the dark, a photo-resistor can have a resistance as high
as a few mega ohms (MΩ), while in the light, a photo-resistor can have a resistance as low as
a few hundred ohms. If incident light on a photo-resistor exceeds a
certain frequency, photons absorbed by the semiconductor give bound electrons enough
energy to jump into the conduction band. The resulting free electrons (and their hole partners)
conduct electricity, thereby lowering resistance. The resistance range and sensitivity of a
photo-resistor can substantially differ among dissimilar devices. Moreover, unique photo-
resistors may react substantially differently to photons within certain wavelength bands.
This property of LDRs can be used to develop tracking mechanisms. As light intensity
increases on the photo sensor, it reduces the variable resistance and thus allows current to
flow which completes the circuit and keeps the motor stationary. As light intensity decreases
on the photo sensor, it increases the variable resistance and thus does not let current pass, and
hence the motor is indicated to be switched on. Sample LDRs are shown in Figure 5.
Figure A3.1 Light-Dependent Resistors (LDRs)

44
APPENDIX 4
PHOTOGRAPHS OF THE PROJECT
Figure A4.1 Initial Experimentation for Project
Figure A4.2 Testing of Tracking Mechanism

45
Figure A4.3 Frame in the Initial Stages of Development

46
APPENDIX 5
SCHEDULE, TASKS, AND MILESTONES
Month Jan'15 Feb'15 March'15 April'15 May'15
Week & Task 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
Literature Review
Study Of Existing Designs
Study Of Methodology
Design Constrains
Trail Methods To Check Feasibility
Of Concentrator
Basic Testing To Find The
Efficiency Of Fresnel Lens
Concept Studies And Working
Revision On Literature Studies And
To Find Voids
Calculations And Design Constrains
Design Specifications
Basic Prototype Of The Project
Testing Of The Prototype
Modification In The Design
Modifying The Materials To Make
It Economic
Final Assembly Of The
Components And Project
Submission
Final Review Of The Project
Figure A5.1 Schedule and Milestone Layout

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