Solar water heater

Design of solar water heater 2015
WOLLO UNIVERSITY (KIOT)
DEPARTMENT OF MECHANICAL ENGINEERING Page i
Abstract
In today‟s world hot water is used for different purposes beginning from house hold to power
generation. In order to attain those purposes peoples are following different ways like heating by
fire wood and electric power. In this paper we have come with a paramount idea of heating water
using solar energy for KIOT student Cafeteria. The student cafeteria uses 7000 liters of hot water
per day, and this hot water is gained from either heating by fire wood or electrical energy.
This design will heat 7,500 liters of water per day and it will satisfy the need of hot water by the
cafeteria, plus the design is 100% environmental friendly. Employing this solar power heater
can solve problems like: consumption of woods, labor, environmental pollution, etc.
Keywords: Fire wood, Heater, Solar Energy and Environmental Friendly

DEPARTMENT OF MECHANICAL ENGINEERING Page ii
Acknowledgement
First of all we would like to thank our God for helping us in doing the project and for all his
provisions that we really in need of. Our deepest gratitude also goes to our advisor Wubishet
Degife for his tireless advice throughout the entire project. There are also others who willingly
supported us by giving paramount ideas like: Kemal Hedano and Tadesse Mayet and at last but
not the list we would like to thank our families for their encouragement to help us in all means.
Authors Name: Kindye .A, Dawit B., Esubalew A. and Taye A.
ID Number: ITR/573/03, ITR/225/03, ITR/870/03, ITR/362/03
Qualification: BSc, Mechanical Engineering
Kombolcha Institute of Technology, 2015

DEPARTMENT OF MECHANICAL ENGINEERING Page iii
Table of Contents
Abstract............................................................................................................................................ i
Acknowledgement ..........................................................................................................................ii
LIST OF FIGURES .................................................................................................................... v
LIST OF TABLE ....................................................................................................................... vi
1. Introduction................................................................................................................................. 1
1.1 Back Ground of the Project................................................................................................... 1
1.2-Statement of the problem...................................................................................................... 2
1.3- Objective of the project ....................................................................................................... 2
1.3.1General objective .................................................................................................................................2
1.3.2-Specific objective...............................................................................................................................2
1.4 Significance of the project .................................................................................................... 2
1.5-Scope of the project .............................................................................................................. 3
1.6-Methodology......................................................................................................................... 3
1.7-Organization of the project................................................................................................... 3
2: Literature Review ....................................................................................................................... 4
2.1 Definition of solar Heating ................................................................................................... 4
2.2 Historical Background .......................................................................................................... 4
2.3 Types of Solar Water Heating............................................................................................... 4
2.3.1 Passive Systems ..................................................................................................................................4
Figure 2 thermo siphon system.............................................................................................................6
2.3.2 Active s systems..................................................................................................................................6
2.4 Types of solar thermal energy collectors ........................................................................................8
2.4.1Unglazed liquid flat plat collectors..................................................................................... 9
2.4.2 Evacuated Tube Collectors..............................................................................................................9
2.4.3 Parabolic Collectors........................................................................................................................ 10
2.4.4 Glazed liquid flat plat collector ................................................................................................... 11
Benefits of Solar Water Heaters ............................................................................................... 13
3. Design Analysis, Result and discussion.................................................................................... 15
3.1- Preliminary Design Concept.............................................................................................. 15

DEPARTMENT OF MECHANICAL ENGINEERING Page iv
3.1.1 Working principle of Solar Power Water Heater................................................................... 15
3.1.1- Materials selection for an active solar water heater............................................................. 16
3.2- Basic system design........................................................................................................... 20
3.2.1-DESIGN OF SOLAR COLECTOR FOR WATER HEATING........................................ 21
3.2.2- Design of the storage tank........................................................................................................ 29
3.2.2-Design of solar collector tube................................................................................................... 33
3.2.4-Design of shaft................................................................................................................................ 35
3.2.5-Design of spur and pinion gear................................................................................................ 40
3.2.6-Handle design................................................................................................................................. 43
3.2.7- Design of frame link and supporting pole.......................................................................... 47
3.2.8 - Design of support link ....................................................................................................... 48
3.3-Pumps selection.................................................................................................................. 50
3.4 General maintenance........................................................................................................... 51
3.5-Manufacturing process ....................................................................................................... 52
3.5.1 Welding and Fabrication............................................................................................................. 52
3.5.2The spur gear manufacturing process: .................................................................................. 52
3.6 Total Cost Analysis............................................................................................................. 54
Table 4 cost analysis ................................................................................................................. 54
4: CONCLUSION AND RECOMMENDATION....................................................................... 57
4.2-Conclusion.......................................................................................................................... 57
4.1-Recommendation................................................................................................................ 58
APPENDIX A STANARRD TABLE FOR DESIGN.............................................................. 59
Appendix B part drawings .................................................................................................................... 62
Reference .................................................................................................................................. 72

DEPARTMENT OF MECHANICAL ENGINEERING Page v
LIST OF FIGURES
Figure 1 Bath (integral collector storage ........................................................................................ 5
Figure 2 thermo siphon system....................................................................................................... 6
Figure 3 direct circulating active system ........................................................................................ 7
Figure 4 direct drain back system ................................................................................................... 8
Figure 5 types of solar thermal energy collector ............................................................................ 8
Figure 6 Unglazed solar collector................................................................................................... 9
Figure 7 evacuated tube collector ................................................................................................. 10
Figure 8 parabolic collectors......................................................................................................... 11
Figure 9 glazing collectors............................................................................................................ 12
Figure 10 working principle.......................................................................................................... 15
Figure 11 copper tube ................................................................................................................... 18
Figure 12 panel position without tilt angle ................................................................................... 26
Figure 13 position of panel with tilt angle.................................................................................... 27
Figure 14 position of panel with the sun path............................................................................... 29
Figure 15 hoop stress distribution................................................................................................. 31
Figure 16 longitudinal stress......................................................................................................... 33
Figure 17 bending movement ....................................................................................................... 39
Figure 18 Isometric assembly drawing......................................................................................... 55
Figure 19 assembly drawing......................................................................................................... 55

DEPARTMENT OF MECHANICAL ENGINEERING Page vi
LIST OF TABLE
Table 1 selection criterion of solar collector................................................................................. 19
Table 2material specification of solar collector............................................................................ 19
Table 3- analysis of day of year.................................................................................................... 24
Table 4 cost analysis ..................................................................................................................... 54
Table 5 over all dimension............................................................................................................ 56

DEPARTMENT OF MECHANICAL ENGINEERING Page 1
1. Introduction
1.1 Back Ground of the Project
Using solar energy to heat water is not a new idea. More than one hundred years ago black
painted water tank were used as simple solar water heater. Solar water heating technology has
greatly improved during the past centuries. Solar power has a long history for its starting in
1876William Grylls Adeams and his student; Richard Evan discovered that an electrical current
could be generated from selenium solely by exposing it to light. [1]
In 1953, the first solar cell was made from selenium. And in early 1960s solar cells were able to
power both American and Soviet satellites. The solar cells advancement is increasing year to
year and demand of availability varies for different purposes. Among those mechanisms using
black tube Solar glass to absorb energy from sun light radiation. Now day‟s solar energy is used
for different purposes like power production and water heating Ac systems and the likes. [1]
The Solar Water Heating Systems – Design Guide is the first attempt to develop
recommendations on optimal and reliable configurations of solar water heating systems in
different climates along with design specifications, planning principles, and guidelines for such
systems that serve building clusters with significant domestic hot water needs (e.g. for cocking,
boiling tea, cooling, making Injera) that operate in combination with central heating systems
[13].
Solar water heating is one form of using radiation energy to heat or boil water. Solar thermal
systems are commonly used for the domestic water heating, and space heating. The efficiency
and performance of solar water heating system depend on a site or orientation of the plate. Solar
source is measured by the solar radiation intensity of an area; also cloud cover and latitude are
factors of the system [5].
This Energy means is appropriate for KIOT student cafeteria hence; it is renewable,
environmental friendly, and without service cost. Our countries latitude is appropriate to install
and use solar energy for different purposes in this case for water heating.
KIOT‟s student cafeteria is using fire wood for boiling water for different purposes. The need of
hot water demand is increasing from time to time as the number of students is increasing in each
year. What they are using now (fire wood) is not efficient and environmentally friendly plus it is
not adjusted to get optimum temperatures of hot water for different applications at different
temperatures.

1.2-Statement of the problem
In KIOT student cafeteria hot water is attained by firing wood. This method of heating water has
so many draw backs which makes the laborers life harder. Wood firing has the following
disadvantages:
 Health
 Lesser quality
 Stress on workers
 Environmental pollution
These problems have initiated us to design solar water heater for the cafeteria. Therefore,
employing solar water heating system for the student cafeteria is significant to overcome the
listed problems, with advantage of safer environment.
1.3- Objective of the project
1.3.1General objective
The goal of this project is to design solar water heater that can deliver 7,500 liters of hot water
for KIOT student cafeteria.
1.3.2-Specific objective
1. To design two water storage tanks each with 7500 liters storage capacity
2. To design water connecting pipe
3. To select a pump delivering ⁄ of water to the system
4. To design a shaft with bending moment capacity of 2.8845KNm
5. To design spur gear
6. To select temperature sensors
7. To select absorber and insulator
8. To select valves
9. To design supporting frame links and poles
1.4 Significance of the project
The need of this project is on studying the problem of hot water supply for KIOT student
cafeteria and coming up with ideas of solution in order to stop the former mechanism (fire wood)
of hot water supply and gain the following advantages:
 It will improve human power induced
 It will save energy
 It will reduced deforestation
 It will minimize environmental pollution
 It will save time

 It will increase service quality
 It will supply distilled water
 It will heat water at optimum temperature
 It will create safer environment To decrease stress on the workers
1.5-Scope of the project
The scope of this project is limited on the design and selection of solar water storage tank, solar
collectors, pumps and pipes. And its capacity is limited to delivering 7500liters of hot water per
day, plus it incorporates mechanically adjustable system for the panels which allows maximum
traction.
1.6-Methodology
Designing of solar water heater is achieved by the following standard methods of designing
mechanical system. The research methodology of the project is as follows:
 Literature survey; in this stage, the existing works related to solar water heaters are
studied and reviewed.
 Selecting the best mechanism among different alternatives: this is achieved by
 Firstly formal need analysis of the problem
 Secondly by bringing the system analysis the different parts that that
composes the mechanism.
 Thirdly by interconnecting the function of the different parts that
compose the mechanism.
 Finally selecting the best mechanism by prioritizing criteria.
 Technical analysis; the different parts and components of the selecting mechanism are
designed in detail by considering different internal and external effects on mechanism.
For technical analysis we have used analytical design manuals and AUTO CAD.
1.7-Organization of the project
This project is organized by four chapters: the first chapter introduces the background, statement
of the problem, objectives, significance of the study, scope and methodology of the study. The
second chapter deals the overview of solar water heaters and literature survey. Preliminary
design concepts, design works, results and discussions are incorporated in chapter three. The
final chapter illustrates conclusion and recommendation of the study.

2: Literature Review
2.1 Definition of solar Heating
Solar water heating (SWH) is the conversion of sun light in to renewable energy for water
heating using a solar thermal collector. Solar water heating system comprises varies technologies
that are used worldwide increasingly. [12]
2.2 Historical Background
In the 1760s, Horace de Saussure observed "It is a known fact, and a fact that has probably been
known for a long time, that a room, a carriage, or any other place is hotter when the rays of the
sun pass through glass.” de Saussure built a rectangular box out of half-inch pine, insulated the
inside, and had the top covered with glass, and had two smaller boxes placed inside. Sunshine
penetrated the glass covers. The black inner lining absorbed the sunlight and converted it into
heat. Though clear glass allows the rays of the sun to easily enter through it, it prevents heat from
doing the same. As the glass trapped the solar heat in the box, it heated up.
The earliest solar hot water collectors, dating back to the nineteenth century, were tanks filled
with water and painted black. The downside was that even on clear, hot days it usually took from
morning to early afternoon for the water to get hot. And, as soon as the sun went down the tanks
rapidly lost their heat because they had no protection from the night air.
In 1909, William J. Bailey patented a solar water heater that revolutionized the business. He
separated the solar water heater into two parts: a heating element exposed to the sun and an
insulated storage unit tucked away in the house so families could have sun heated water day and
night. The heating element consisted of pipes attached to a black-painted metal sheet placed in a
glass-covered box. Because the water to be heated passed through narrow pipes rather than sat in
a large tank, Bailey reduced the volume of water exposed to the sun at any single moment and
therefore, the water heated up faster. Providing hotter water for longer periods put Bailey's solar
hot water heater, called the Day and Night, at a great advantage over the competition. [12]
2.3 Types of Solar Water Heating
2.3.1 Passive Systems
“Passive” systems solar hot water systems do not have a pump or other moving parts. These
heating systems rely on temperature changes in the water located in the solar collectors on the
roof to move the water through the system. They are typically less expensive than systems
having a pump (active systems) because they have no mechanical parts, but they are usually not
as efficient. However, passive systems can be more reliable and may last longer. There are two
basic types of passive systems: batch and thermo siphon. [11]

Batch or Integrated collector-storage (ICS) systems: These systems work best in areas where
temperatures rarely fall below freezing. They also work well in buildings with significant
daytime and evening hot-water needs. Batch collectors (Figure1) or ICS; use one or more black
tanks or tubes in an insulated, glazed box. Cold water first passes through the solar collector and
is preheated. The water then continues on to the conventional backup water heater, providing a
reliable source of hot water. This type of collector should be installed only in mild-freeze
climates because the outdoor pipes can freeze in severely cold weather. [14]
Figure 1 Bath (integral collector storage
Thermo siphon systems: Thermo siphon systems (Figure2) move water through the system due
to density differences (warm water rises as cooler water sinks). Neither pumps nor electricity are
used. However, the collector must be installed below the storage tank so that warm water can rise
into the tank. These systems are reliable, but contractors must pay careful attention to the roof
design because of the heavy storage tank. Although they are usually more expensive than ICS
systems, they can be used in areas with less sunshine.
Passive solar water heating systems are used on individual buildings or for a single heating
demand. They are not for central heating systems that service several buildings. They are also
inefficient in cooler climates. Since the purpose of this design guide is to focus on systems that
can serve multiple buildings, these systems will not be further discussed. [14]

Figure 2 thermo siphon system
2.3.2 Active s systems
Solar water heating systems that rely on electric pumps to circulate fluid through the collector
are called “active systems.” Active systems are generally categorized into two types: direct and
indirect, which simply means that water in the storage tank is either directly filled using the hot
water flowing from the solar collectors (one loop) or indirectly using two water circulating loops
separated by a heat exchanger. The latter type is normally used in locations where outdoor winter
temperatures below freezing may occur. These systems use an anti-freeze solution such as a
water glycol mixture as a heat transfer medium that circulates through the collectors to avoid
freezing.[10]
Direct circulating active system (no anti-freeze): These systems use pumps to transfer the sun's
energy directly to potable water by circulating this water through the collector tubing and storage
tank; no anti-freeze solution or heat exchanger is used. The pumps circulate water through the
collectors, into the building, and back again. They work well in climates where it rarely freezes.
A direct active system (Figure -3) has one or more solar energy collectors installed and a nearby
storage tank. The system uses a differential controller that senses temperature differences
between water leaving the solar collector and the coldest water in the storage tank. When the

water in the collector is about 15 to 20 °F (-9 to -7 °C) warmer than the water in the tank, the
pump is turned on by the controller. When the temperature difference drops to about 3 to 5 °F (-
16 to -15 °C), the pump is turned off, so the stored water always gains heat from the collector
when the pump operates. A flush-type freeze protection valve installed near the collector
provides freeze protection. Whenever temperatures approach freezing, the valve opens to let
warm water flow through the collector. The collector should also allow for manual draining by
closing the isolation valves (located at a height above the storage tank) and opening the drain
valves. Automatic recirculation is another means of freeze protection. When the water in the
collector reaches a temperature near freezing, the controller turns the pump on for a few minutes
to warm the collector with water from the tank.
Another type of direct active solar water heating system is called “a drain back-system” (Figure
4), which is also designed for cold climates. This type of system typically uses regular water as a
heat transfer fluid, and is designed to allow all of the water in the solar collector to “drain back”
to a holding tank in a heated portion of a building. When no sunlight is available for heating, the
solar pump turns off and the water flows into the drain back tank by means of gravity. Since
these systems use water, they can be designed with or without a heat exchanger.[26]
Figure 3 direct circulating active system

Figure 4 direct drain back system
2.4 Types of solar thermal energy collectors
Figure5 shows the four different types of solar hot water collectors. The type of collector
chosen for a certain application depends mainly on the required operating temperature and the
given ambient temperature range. Due to the design and simplicity of design each type has a
maximum temperature that they are best suited to provide:
 Unglazed EPDM collector - below 90 °F (32 °C)
 Flat plate - below 160 °F (71 °C)
 Evacuated tube - up to 350 °F (177 °C)
 Parabolic trough - up to 570 °F (299 °C)
Figure 5 types of solar thermal energy collector

2.4.1Unglazed liquid flat plat collectors
It‟s usually made of a black polymer. They do not normally have a selective coating they are
usually simply laid on or off or on wooden support. These dew-cost collectors are good at
capturing the energy from the sun, but thermal losses to the environment increase rapidly with
H2o temperature particularly in widely locations.
As a result unglazed collector are commonly used for applications requiring energy delivery of a
low temperature (pool heating make up water in finished forms, process of heating applications
etc) in cold climate they are typically e collector. [7]
Figure 6 Unglazed solar collector
2.4.2 Evacuated Tube Collectors
Evacuated tube collectors (Figure7) can be designed to increase water/steam temperatures to as
high as 350 °F (177 °C). They may use a variety of configurations, but they generally encase
both the absorber surface and the tubes of heat transfer fluid in a vacuum sealed tubular glass for
highly efficient insulation. Evacuated tube collectors are the most efficient collector type for cold
climates with low level diffuse sunlight.

Figure 7 evacuated tube collector
2.4.3 Parabolic Collectors
These collectors use curved mirrors to focus sunlight onto a receiver tube (sometimes encased in
an evacuated tube called CPC or compound parabolic collectors) running through the middle or
focal point of the trough (Figure8). They can heat their heat transfer fluid to temperatures as high
as 570 °F (299 °C). Such high temperatures are needed for industrial uses and for making steam
in electrical power generation. Because they use only direct-beam sunlight, parabolic-trough
systems require tracking systems to keep them focused toward the sun and are best suited to
areas with high direct solar radiation like the desert areas of the Southwest United States. These
collector systems require large areas for installation, so they are usually ground mounted. They
are also particularly susceptible to transmitting structural stress from wind loading and being
ground mounted helps with the structural requirements.[7]

Figure 8 parabolic collectors
2.4.4 Glazed liquid flat plat collector
The glazed liquid flat plat collector is shown in fig 9. a flat plat absorber (which often has a
selective coating is fixed in a frame between a single or a double layer of glass and an insulation
panel of the back much of the sun light (solar energy) is prevented from escaping due to the
glazing (the <<greenhouse effect>>) these collector are commonly used in moderate temperature
application, (e.g. domestic hot water, space heating, year round indoor pools and process heating
applications.
Generally the roles of glazing in solar collector are:
1. To minimize the heat loss from the absorber plate o the environment;;
2. To transmit as much as solar energy possible to the absorber plate;
3. To shield the absorber plate from direct exposure to weathering;
Usually the side and the bottom of the plate are insulated to minimize the heat loss. The absorber
heat is must be black in order to increase the absorption.

Figure 9 glazing collectors
The most important and most expensive single component of an active solar energy system is the
collector field, which may be performed in a several version as from constrictions of solar
collectors. Solar collector is a mechanical device which captures the radiant solar energy and
converts it to useful thermal energy. [4]
There are two types of solar water heating system; [10][11]
1. Active solar water heating system
2. Passive solar water heating system
An active system is one where the exchange fluid is actively pumped from the storage tank
though the collectors and back in o the tank, electric collectors, a small pump, valves and other
components are needed for proper operation and future ability to service the system work as first
the fluid is pumped up in to the roof top collectors where it is heated. It is then sent though heat
exchanger typically attached to or near storage tank.
Indirect system uses a heat transfer system fluid which is usually a water anti freeze mixture.
After the heat transfer fluid is heated in the solar collector, it is pumped to a storage tank where a
heat exchanger transfer the heat from the fluid to the house hold water this type of system is
known as closed loop system.
Direct system heat the actual house hold water in the solar collectors. Once heated the water is
pumped to a storage tank and then piped to faults for use in a home ( house hold) since this
system is uses regular house hold water in the collector it should only be used in area that do not
experience freezing condition. These types of system are also known as an open loop system.
[10]

Passive solar technology are means of using a sun light for useful energy without use of active
mechanical system as an active solar water heater passive solar heating relies on a gravity or
natural convection to circulate heated house hold water through the system without any pump.
Passive systems are not efficient as active system but less expensive than active system,
therefore we have selected active direct system based on the above discussion.
Solar water heaters, sometimes called domestic hot water system may be a good investment for
our needs. Solar water heaters are cost competitive in many applications when we account for the
total energy cost over the life of the system. The system is use the sun to heat either water or
water glycol antifreeze mixture, in collectors mounted on the roof rotates with respect to the sun
path. The heated water is then stored in a tank similar to other system. The system is used pump
to circulate the fluid through the collector.
Solar water heaters can operate in any climate. Performance varies depending, in part, on how
much solar energy is available at the site, but also on how cold the water coming into the system
is survived with required. The colder the water, the more efficiently the system operates. In
almost all climates, you will need a conventional backup system i.e. the path of the sun. In fact,
many applications require you to have a conventional water heater as the backup. [11]
Benefits of Solar Water Heaters
There are many benefits to owning a solar water heater, and number one is economics. It is
renewable energy because of the benefits of solar water heating, adding a unit to the required
will also increase its value. So you could end up getting back whatever money you put into a
solar heating system when you use every time. Solar water heater economics compare quite
favorably with those of electric water heaters, so attractive when compared with those of gas
water heaters. Heating water with the sun also means long-term benefits, such as being
cushioned from future fuel shortages and price increases, and environmental benefits.
Based on this solar energy we want to solve the problem of wollo university KIOT student
cafeteria. As we know in Wollo University KIOT student cafeteria servants (workers) are used
heated water for prepare tea and washing basing and kitchen equipment and this hot water uses
cooking Wote. But; they boil or heated by the use of fire wood as source of heat. During this
process the workers scarify their value of life regarding to health, time delay, quality of food, so
on. To avoid such problems solar power water heater with flat plat collectors are favorable.
Most of the existing solar water heater is fixed in position that means doesn‟t rotate with the sun
position due to this the service is limited to in a fixed position. Therefore our solar panel is
movable with sun angle position.
Our project is different from the previous solar water heater the solar panel is rotate with the sun
angle position using spur gear with pinion gear by rotating that mounted on the horizontal

shaft with manually. Why we make this solar panel movable is to get enough solar energy from
sun according to its position and to increase the service.

3. Design Analysis, Result and discussion
3.1- Preliminary Design Concept
3.1.1 Working principle of Solar Power Water Heater
Solar panel collect the sun radiation and then convert in to heat energy the cold water becomes
hot by using pump which is pumped from the storage tank and circulating in to the panel pipe
and to heated hot water regulator then to store the insulation tank. Finally the hot water used the
user as the required goals.
Figure 10 working principle
Solar hot water thermal system: the main components added to a radiation heating system
when solar thermal energy is used are:
 Collector field with collector field piping and support structure
 heat transfer fluid
 a storage tank system

 pump for solar loop and other pump for other loop
 expansion and safety device for each closed loop
 a controller with temperature sensors in a collector field and storage tank and that
turns the pump on and off.
3.1.1- Materials selection for an active solar water heater
1. Copper tubes, this tubes used for making the manifold of riser and heater pipes for
water carriage in the collector. The copper tube of idea (12.7mm and 25.4mm) was used
respectively.
2. Aluminum foil, it was used for making the absorber plat and as insulating material
from the outside of collector
3. Glass wool, was used for making the collector box and stool (set without a back) for
tank
4. Poly glass was used for glazing of collector usually thickness of 4-5mm
5. Silken paste was used for sealing the collector with glazing to avoid any leakage.
6. Iron angles were used for making stand frame for solar collector.
7. Pump, centrifugal type pump have been used storage tank circulating the water in the
collector
8. Aluminum was used for making the storage tank
9. Copper roads, was used for welding of copper tubes. (Read detail)
10. Valve, where used for proper flow control
11. paint were used to painting the supporting stand and storage tank solar radiation
failing on the absorber plat was heating the metal plate and some of heat was transferred
to water flowing through tubes.
12 fiber glass E-type is used for making pipe from collector to storage , because of fiber
glass has high heat resistance in order to reduce heat loss while the heated water flow
from collector to storage tank.
Aluminum foil: aluminum foil is widely regarded as the most effective barrier material in
flexible packaging ,giving almost perfect protection against light and suppressing any transport
of matter .foil is usually converted to flexible packaging laminates by traditional converting
process ,such as, lacquering or 2 –component –adhesive lamination but more and more extrusion
coating and extrusion lamination are being used .almost all is put through an annealing process
,to produce an appropriate surface ,which is good and homogenous as possible with regard to
unwinding properties (at high speed), wet ability, adhesion and chemical resistance the effects
on adhesion performance as a result of replacement of traditional sealants and adhesives by
extrusion coating are described for selected types of packages and packaged goods .[24]
requirements on packaging specially seal performance are usually mastered ,but major effects
such as the interactions between package and the field good are often for gotten .the main
reason for using aluminum foil in the flexible packaging lies in the need to completely super

press migration permeation through the package and shield the package d good from the
environment in the most suitable way.
Aluminum foil is usually produced by rolling down strip in number of subsequent by rolling
down strip in a number of subsequent cold rolling steps, which reduce the material thickness by
almost a half in each step. Besides recrystallising the gain structure of the foil and removing the
rolling oil as far as possible ,the main tasks of annealing are to produce a surface which is not
only even ,homogenous and but also displays good wet ability and adhesion properties the best
layer integrity without any defects is seen in pure aluminum foil. Theoretically it has the best
chemical attack. Since there is a need for mechanical strength in converting and packaging
applications, however, alloys with specified grain structure and distribution as well as
perceptions of a particular type and size are required. Aluminum foil surface is well-prepared for
efficient wetting, bonding and adhesion durability. Coating or adhesives the most important pre-
requisite for durability, if they spread the surface completely .plastic coating adhesion the right
choice for the function barrier must be taken. [23]
Aluminum for tank: in the 1890s, aluminum had become popular for lightweight application s
and was used for household cookery, among other applications .Experimental small craft were
constructed of aluminum, further use seemed promising. the first sizable craft constructed of
aluminum was the sloop-rigged yachted vendees‟, which was built at St. Aluminum was first
used in the U.S .navy for some topside fittings for the torpedo boats intended for the battle ship
USS Maine.[2]
Material characteristic: in addition to standard aluminum alloys that have seen many years of
satisfactory service in marine environment, manufacturers have developed new alloys for use in
ship and boat construction. The U.S. Aluminum association maintains the international
standards for aluminum alloys ,including tamper designation ,chemical composition and material
properties .recent problems with corrosion of aluminum from a particular producer led to
revision of the standards of the American society of testing and materials ,and thus standards are
being adopted internationally ,including by the international association of classication of
societies .The marine –grade aluminum alloys used to day have generally good corrosion
resistance .Until recently, there were no standards for evaluating corrosion resistance in actual
seawater environments, and developers of new alloys relied on accelerated lab tests that had not
been rigorously correlated with field-testing to verify suitability of their products for use in
marine environments. Extruded, which leads to structural details that unique to aluminum
structure. The result is generally lighter structure at a reduced total cost. [20]
The copper tubs were joined by welding. Copper road was used for welding the roads. The
arrangement of copper tubes is caring of fluid as shown fig (11). It is better to double glazing
was used as to protect the loss of heat. The thickness of inner glass was kept 3mm and outer

glass 5mm. double glazing result more absorption of heat at the inner side glass is effective in
reducing radiated heat loss because opaque to the longer wave length infrared radiation and re
emitted by the hot absorber plat.
Figure 11 copper tube
One of the key element to design it must be selected the components (material) of solar power
Water heater is among this, solar panel (collector) storage tank, pump, batter (storage solar
energy), sensor to measure heat, water level.
Solar collector selection: Flat plat collectors are the most common collector for water heating (
liquid type ) because to reduce additional material like compressor or as for space heating
insulations ( air type) in simple words a flat plat collectors is an insulated meta with glass cover,
which is called glazing. It is very easy to explain the working phenomenon of flat plat collector.
The sun light passes though the glazing and strikes the absorber plat. The absorber plat then
starts to heat up concentrating solar radiation in to heat energy the heat is then transferred to
liquid passing though the flow tube most solar collectors are boxes, frames, or room. [19] That
contains these parts:
 Clear cover that let in solar energy.
 Dark surface inside, called absorber plates that soak up heat.
 Insulation materials to prevent heat from escaping and
 Vents or pipe that carries that heated air or liquid from inside the collector to where it
can be used.
Clear cover: Much clear material may be used as covers for solar collectors can be used as
covers for solar collectors, but glass is the most common materials. Glass can be made quickly
and easily. The special glass used in solar collectors resists breaking and scratching. When sun
light pass though glass and heat a surface inside a solar collectors it changes in to heat, although
glass allows sunlight to pass though it also traps the heat produced inside the collector. [12]

Absorbers: The heat produced inside a solar collector is soaked up by metal sheet or containers
filled with water that have been painted black or another dark color. These dark colored objects
that soak up heat are called solar heating system could not produced enough heat to warm room
inside the house.
Insulation: Heat always tries s to move from a hotter object to a colder one insulation is what
prevents or slows down the movement of heat. Because insulation prevents the heat inside a solar
collector from moving to the outside where the temperature is lower, it is important part of any
solar collector.
Vent and Pipes: When a solar collector is working properly, the heat that it produce move from
the collector to an area where that it can be used. If the collectors job is to heat air, then vents,
ducts (air tubes), and fans carry those heated air from the collector to another part of the house. If
the collector‟s job is to heat water, then pipes, tubes, and pups to move water from the collector
to water heating or space heating system equipment.
Table 1 selection criterion of solar collector
Type of
material
Size Power Weight Cost Efficiency
Mono crystal
line
1m×1.9m Above 285w Optimum Optimum Medium and
high
Poly crystal
line
1m×1m Power less Flexible Simple cost Lower
amorphous Depend on
the condition
Lower Medium Undefined 30 % (lower)
Generally we can select based on the following properties.
Table 2material specification of solar collector
s/no Collector type Overall
efficiency
a1[W/(k.m2
)] a2
1 High performing
evacuated tube
collector (ETC)
0.75 1.0 0.005
2 High performing
flat plate
collector(FPC)
0.8 3.0 0.008
3 Medium
performing FPC
0.75 4.0 0.010

Therefore we can choose of collector type depends on several factors such as:
 Price
 Efficiency
 Operating temperature
 Location (available solar radiation, ambient temperature)
In most cases the largest system flat plate collectors are used based on the Table 1 and 2 in order
to fulfill the required temperature. One advantage of FPCs is that they are made in larger unite
compared to ETCs, So that we select flat plat collectors. [19]
Type of water storage portable tank selection: The best way of selection of solar water storage
tanks aluminum is fulfill several factors of domestic water. The design of aluminum water tanks
support section should be conform to the design construction standard.
Consideration: Cylindrical shell design of the water tanks should give investigation on the buck
lining of the cylindrical shell conforming circular cylindrical shells under axial compression and
internal pressure. The water tanks and pipe line design should give full preventive measures to
corrosion.
3.2- Basic system design
Solar water heaters are made up of collectors, storage tank, and depending on the system it needs
pump in order to circulate the fluid through the collector. Our design is established based on the
active system and it needs pump. The pump in active system in solar water heaters has low
power requirement and some requirements now include direct current pump powered by small
solar energy i.e. panels distinct sections in rectangular forming control fixed instrument.
Collectors: the energy delivered of solar water heating system depends on the collector types
and condition of cloud cover, site latitude, orientation to path of sun, shading, etc.
Cloud cover: the power of solar radiation entering the atmosphere, or the” solar constant “is
1367W/ .with the atmosphere, this power is reduced by absorption scattering and reflection
effects to about 1000W/m2
on the earth‟s surface if there is a clear sky. The solar radiation that
reaches the earth‟s surface is further reduced by clouds, which reflect part of the radiation back
into space, and absorb another part. Diffuse irradiation on the earth‟s surface consists of the
irradiation coming from angles different than the solar incidence angle (i.e., the actual sun
position), and (due to scattering), it also changes the relation between beam and diffuses
radiation. As the cloud cover changes with the seasons, thus effects are also seasonal dependant.
[26]
Site latitude: The latitude of the site will affect the solar radiation collected, so it is important to
tilt panels based on the latitude of the installation site. The sun slants for south during the shorter

days of the month starting from October up to January when the sun follows southern part path
in the sky. For this reason, solar collector should face true south in the northern hemisphere.
Solar collector tilt: Solar systems should be designed to match the heating demands with the
solar energy intensity that varies throughout the year in the northern hemisphere ,a solar thermal
system will receive less solar radiation in the summer than in winter . To improve the seasonal
solar energy collection the solar collector can be tilted so, that it would be more perpendicular to
the suns path when the heating demand is greatest. [26]
Orientation to path of sun: Two angles describe the orientation of the collector:
The azimuth angle , also called compass orientation. The angle is in a horizontal surface
between the collector and the due south direction. Due south, towards the equator, is by
definition sun orientation of 0 .
The tilt angle β (sky ward orientation): the angle between the collector and the horizontal
surface.
Basically three types of collectors, flat plate, evacuated-tube and concentrating collectors. Based
on these concepts our system design stands on flat plate collectors. These flat plat collectors the
most common type, is an insulated, weather proofed box containing a dark absorber plate under
one or more transparent or translucent cover. The plate heats up and transfers the heat to the fluid
flowing through tubes in or near the absorber plate. When the fluid circulates through the
collector the water is heated and then it is available for the required. That is the system uses
water as the heat transfer fluid in the collector loop. When the pumps are off, the collectors are
empty, which assures freeze protection and also allows the system to turn off if the water in the
storage tank becomes too hot. [26]
3.2.1-DESIGN OF SOLAR COLECTOR FOR WATER HEATING
Basics of solar energy: Since the solar water heating model deals with solar energy, some basic
concepts of solar energy engineering first needs to be explained. This section does intend,
however, to detail the calculation of a few variables that will be used throughout the model.
Declination: the declination is the angular position of the sun at solar noon, with respect to the
plane of the equator. Its value in degree is given by cooper‟s equation;
3.1

Solar hour angle and sun set hour angle: The solar hour angle is the angular displacement of
the sun east or west of the local meridian; morning negative after noon positive. The solar hour
angle is equal to zero as solar noon and varies by 15 per hour from solar noon. The sun set hour
angle is is the solar hour angle corresponding to the time where the sun sets. It‟s given by the
following equations.
3.2
Where;
-the latitude of the site .specified by the user Extraterrestrial and clearness index
Solar radiation outside the earth‟s atmosphere is called extraterrestrial radiation.
Daily extraterrestrial radiation on a horizontal surface, , can be computed for the day of year n
from the following equation:
( (3.3)
Where are the solar constant equal to 1367 W/m2
and other variable have the same meaning
as before.
Before reaching the surface of the earth, radiation from the sun is attenuated by the atmosphere
and the cloud. The ratio of solar radiation at the surface of the earth to extraterrestrial radiation is
called clearness index. Thus the monthly average clearness index, ̅ is defined as
̅
̅
̅
(3.4)
Where ̅̅̅the monthly is average daily solar radiation on horizontal surface and ̅ is the monthly
average daily extraterrestrial daily solar radiation on horizontal surface. ̅ Value depends on the
location and the time of year considered; they are usually between 0.3(for overcast climates) and
o.99 (for very sunny locations).
Monthly average daily diffuse radiation is calculated from global radiation through the following
formula:
For value of the sun set angle less than 81.4
̅
̅
̅ ̅ ̅ (3.5)
̅
̅
̅ ̅ ̅ (3.6)

The monthly average daily beam radiation ̅ is simply computed from:
̅ ̅ ̅ (3.7)
Sky temperature: sky long wave radiation is originated from the sky at wave lengths greater
than 3 m. It is required to quantify radiation transfer exchanges between a body (solar collector)
and the sky. An alternate variable intimately related to sky radiation sky temperature Tsky which
is the temperature of an ideal black body emitting the same amount of radiation. Its value in
is computed from sky radiation Lsky through:
(3.8)
Where is the Stefan-Boltzmann constant Sky radiation varies
depending on the presence or the absence of clouds – as experienced in everyday life, clear night
tend to be colder and overcast nights are usually warmer. Clear sky long – wave radiation (i.e.in
the absence of cloud) is computed using Swanbank‟s formula:
Where Ta is ambient temperature expressed in . For cloudy (overcast) sky, the model that
clouds are at temperature (Ta -5) and emit long wave radiation with an emittance of 0.96 that is,
overcast sky radiation computed as:
)
The actual sky radiation falls somewhere in between the clear and the cloudy values if c is the
fraction of the sky covered by clouds sky radiation may be approximately by:
(3.11)
To obtain a rough estimate of cover the month, the model establishes a correspondence between
cloud amount and the fraction of monthly average daily radiation that is diffuse.
A clear sky will lead to a diffuse fraction
(3.12)
To compute a speed of water in a pipe and input energy output power, efficiency of collector,
volumetric rate etc. when the input energy can be calculated:

Solar insolation can be calculated as per day:
It is better to analysis of the day of month in a year to be comparing a small value of temperature
in KOMBOLCH listed as follow in the table:
Table 3- analysis of day of year
Month Day of month Date Day of year
January 31 16 47
February 61 16 76
March 89 14 103
April 120 15 135
May 151 15 166
June 181 16 197
July 211 15 226
August 242 16 258
September 272 16 288
October 302 15 317
November 333 16 349
December 364 16 380
From the above table the day counting based on calendar calculation of the date and takes the
value of “n” at the minimum temperature in appendix A1. The minimum temperature can be
taken in the following experimental values in KOMBOLCHA location:-
Therefore the minimum temperature records on December, so the value of n can be taken as
380.substitute the value of n in the above equation (3.1):
Therefore the value of sun set hour angle can be calculated as follow from equation (3.2)

Since the value the sun set hour angle greater than 81.4 , we use equation (3.3) i.e.
(
(
) = 66953225.53J/m2
To determine the monthly average clearness index,̅ from equation (3.4):
To determine the monthly average daily solar radiation on a horizontal surface ̅ and ̅ is the
monthly average extraterrestrial daily solar radiation on a horizontal surface.
̅ ⁄
̅ ⁄
̅
̅
̅
From equation (3.6) ̅ ⁄
From equation (3.7) ̅ ⁄
̅
̅
⁄
⁄
⁄
The sky temperature is related to the sky radiation which is equal to:
Then it can be put in the form of power of the radiation of the sun divided by day radiation:

This sun radiation energy depends on the inclined of solar radiation geometric factor ( ) the
ratio of tilted to horizontal surface of beams or collectors in the following equation.
=
Figure 12 panel position without tilt angle

Figure 13 position of panel with tilt angle
The value and value can be calculated the relation of:
) ½
= 67.37°
Therefore:
Inclined solar insolation becomes:

The total energy output can be calculated by solar insolation and collector. Then output energy
is:
Therefore our design needed 6 collectors to produce the required hot water
Then to determine the input energy (QI)
Where - overall efficiency, for the flat- plate collectors is equal to 80% from the table:
⁄
The power on the collector can be computed by collector efficiency [20]:
Total irradiation can be calculated as follow:
⁄
The efficiency of the collectors is computed as:
( ) ( )
⁄
⁄
( ⁄
)⁄

Using the lever handle the position of the panel can be adjusted as the required position of the
sun radiation and the position of the panel is as follow:
Figure 14 position of panel with the sun path
Result: the power of solar collector is achieved that amount of heat energy to transfer the water
pipe and then can be heated easily throughout the collector area. Already the input and output
energy, solar collector power, collector efficiency are done by the reference of environmental
temperature.
3.2.2- Design of the storage tank
Materials selections and analysis
Water heater tanks or solar storage tank are in series with the collector and pump. In this
arrangement, the solar water heater preheats water before store in the storage tank. From this
storage tank the solar water heater is used pump to recirculation warm water through collector
and exposing piping. A challenge in applying renewable energies is often the mismatch between

the time energy is needed and the time energy is available. Thus storage tanks are a necessary
part of any hot water system since they couple the timing of intermittent solar resource with
timing of hot the water load.
Portable water storage are normally constructed using reinforced concrete, pre stressed concrete,
stainless steel, aluminum, steel tank, or any combination of these materials. Based on this
condition we select the parameter of weight and corrosion resistance.
Based on appendix A2 the mass density it is better to selects aluminum materials. Suitable
measures should be taken to prevent a sudden internal pressure drop caused by any uncontrolled
release of water. Bigger commercial solar hot water systems are basically the same as those
used for homes, except that the thermal storage tank, heat exchanger and piping are larger. The
storage tanks in these applications are commonly aluminum as well as steel with an enameled
interior coating. The sizes of this components are proportional the size of the collector array.
Most systems include a backup energy source such as an electric heating element or are
connected to a gas or fuel fired central heating system that will heat the water in the tank if it
fails below a minimum temperature setting, enabling the system to work year-round in all
climates. If the solar hot water system provides for some of a larger storage tank may be
advisable. The storage tank temperature must satisfy the required service temperature and
quantity. A hotter temperature than the service requirements in the storage tank allows for
greater storage of heat, but reduces the collector efficiency. This consideration for the storage
tank normally results in a design that provides stratified water condition in the tank with the hot
water and the cold water. The most commonly used storage tank systems are used for short –
term storage, and are designed to store surplus solar energy. Long term storage tank system can
compensate for seasonal fluctuation in solar irradiation between winter and summer, which can
include solar fractions. Thermal losses from the storage tank have significant effect on the
efficiency of the solar thermal system. Heat is lost via the surface. The capacity of sensible
storage tank (aluminum) is defined by its volume.
The purpose of the tank is to accumulate the required amount of the hot water. The storage tank
connects the pump and the collector in order to facilitate work condition. This storage tank can
be design based on the amount of water which related to the circumference of its dimension. The
amount of water is needs for different purpose up to 7500 liters and more than available and need
of population fulfill their needs/ goals. Based on this reason the dimension of the tank is as
follow:
The storage tank dimension can be calculated considering the volume of water i.e. the amount of
water is 7500 liter. This convert in to in metric system have the following relationship.

Then based on the above relationship we can calculate each dimension of the storage tank. The
relationship of area and volume can be calculated; volume which is equal to area times length.
Since;
Assumed to be the portable storage tank of length is equal to 2.5m; then:
The minimum thickness for hot water tank can be selected based on the following parameter
Classification of vessel (storage tank): according to the dimension; it may be classified as thin
shell or thick shell. If the wall thickness of the shell is less than 1/10 of the diameter of the shell
(d), then it is called thin shell. On the other hand, if the wall thickness of the shell is greater than
1/10 of the diameter of the shell (d), then it is called a thick shell. Thin shells are used in boilers,
tanks and pipes, whereas thick shells are used in high pressures cylinders, gun barrels etc. [22]
According to the end construction; the vessels according to the end construction may classify as
open or close end. A simple cylinder with a piston, such as cylinder of a press is an example of
an open end vessel, whereas a tank is an example of a closed end vessel. In case of closed ends,
longitudinal and circumferential stresses are induced the fluid pressure. [22]
To calculate hoop stress:
Figure 15 hoop stress distribution
Where
p p p p
d
t
x x

P=internal pressure
L=length of the cylinder tank
T=thickness of the cylindrical shape
Total force acting of longitudinal section (along x-x)
(1)
Resisting force acting on the cylinder tank walls ( )
(2)
Equating equation (1) and (2)
(3)
Where; force can be calculated from the input energy divided by the speed of water in a pipe and
then the speed of water which is equal to the square root of two times gravity and height of head
i.e.
√
√
⁄
⁄
The thickness of the storage tank has been selected from the appendix A3 which is t=12mm
From equation (3)
⁄
Assume factor of safety to be 3-5; take 3
That is safe

Longitudinal stress:
Figure 16 longitudinal stress
Total force acting of transverse section (i.e. y-y)
(1)
Resisting force ( )
(2)
Equating the two equations (1) and (2)
m2
The resisting force
I.e. safe
3.2.2-Design of solar collector tube
The diameter of the collector tube can be calculated from the volume flow rate:
To determine the volume flow rate, the amount of water in the tank can be to pass through the
collector pipe is divided to the time taken. The time is depending on the number of pass in the
collector. The time taken is calculated from of power and energy that is the integration of power
yields heat energy. [14] That means:
∫
Where p is power in (watt)
T is time in (second)

⁄ ⁄
Where, v- volume of water
Q- Volume flow rate
t- Time in second
⁄
The mass flow rate of the collector is computed as follow:
⁄
̇
⁄
To determine the speed of water in the pipe, volume flow rate divided by the area the pipe, then
the area of pipe is equal to the volume flow rate divided by the speed of the water in the pipe.
First to calculate the speed of the water in the pipe ( ):
√ Where; h – height of pipe head
√
⁄
The area of the pipe can be computed as:
The diameter of the pipe can be calculated as follow:

Result: the storage tank and the collector pipes are designed based on the amount of water, so
that the diameter of the pipe and the tank, the volume follow rate, the speed of water, and the
time taken, already calculated. In addition to this the longitudinal and hoop stress are determined
to develop on the tank.
3.2.4-Design of shaft
Selection of material; the material used for shaft has the following properties:
 It should have high strength.
 It should have good mach inability.
 It should have low notch senility factor.
 It should have good heat treatment properties.
 It should have high wear resistance properties.
We are selecting the material for design of shaft Carbon steel
The material used for ordinary shaft is carbon steel of 40 c 8, 45 c 8 and 50 c 12. The mechanical
properties of this grade of carbon steel are given in the following table.
The shaft design on the basis of shaft subject to bending moment, when the shaft is subject to a
bending moment only, and then the maximum stress (tensile or compressive) is given by the
bending equation. [25]
Where
I = moment of inertia of cross sectional area of the
shaft about the axis of rotation
= bending stress
Y = distance
We can calculate the diameter of the shaft by using the maximum moment and the bending
stress. According to American society of mechanical engineering (ASME) code for the design of
transmission shaft, maximum permissible working stress in tension or compression may be taken
as:
a) 112Mpa for shaft without allowance for keyways

b) 84Mpa for shaft with allowance for keyways
For shaft purchased under definite physical specifications, the permissible tensile stress
may be taken as 60 percent of the elastic limit in tension Or
whichever is less.
The maximum permissible shear stress may be taken as:
a) 56Mpa for shaft without allowance for keyways
b) 42Mpa for shaft with allowance for keyways
For shaft purchase under definite physical specification, the permissible shear ( )
may be taken as taken as 30 percent of the elastic limit tension ) but not more
than 18 percent of the ultimate tensile strength ( ) in other words, the
permissible shear stress:

To calculating the reaction force by using the moments

To determine the shear force and the bending moment by sectioning in each points
∑ ,

∑

Figure 17 bending movement
Now we can calculate the diameter of the shaft by using the above given
√ ⁄
Where bending stress can be calculated as:
Assumed to be n=2,
√ ⁄

√ ⁄
Therefore the parameter of the shaft is already determined.
3.2.5-Design of spur and pinion gear
A spur and pinion gear is composed of two gears. The spur has teeth cut into it and they mesh the
teeth of the pinion gear. The pinion and spur gear are provides a greater feedback and steering
sensation [24].
A well designed mechanism such as; the spur and pinion gear save effort and time. The spur and
pinion is used to convert between rotary motion to linear change the direction or position of
panel. The diameter of the gear determines the speed of the pinion drives (moves) as the spur
gear turns. Spur and pinion is commonly used in the steering system of rotary motion. A spur
and pinion consists of a pinion engaging and transferring motion and it is used to move the
required direction [25].To determine the dimension of the spur and pinion gear:-
Where,
From the standard the maximum human power is 75 watt and can be rotates 12.5rpm. The teeth
of the pinion gear can be selected based on the pressure angle, from the minimum number of
teeth on pinion:
For 14
For

The panel is mounted on a horizontal beam and changed the direction by the help of pinion and
spur gears rotate the shaft of the gear. Based on the set of tilt angle the tooth of the spur gear is
four times the teeth of the pinion. The speed of the gear ratio is calculated:
And can be calculated;
Tangential tooth load (Ft):
The material for the pinion and the spur is cast steel SAE1030, untreated; allowable stress
For Lewis form factor:
For pinion;
Helical;
Material Y Capacity
Pinion 135 0.10375 14.3
Spur 103 0.119 12.257
The capacity of the spur is less than the pinion. Hence, design is to be considered based on the
spur.

,
(1)
Lewis equation for tangential tooth load:
Where, Lewis factor
P = pitch =
Assume the face width is equal to
The value y is taken the spur,
(2)
√
Therefore we choice the value of
Therefore we can determine the dimension of the pinion and the spur gear:

Pitch diameter;
For pinion
For spur gear,
Center distance
Face width (b),
Pitch,
Tangential tooth load
For addendum,
Dedendum,
Addendum diameter,
For pinion,
For spur,
Result: the required dimension of gear is determined and existing all parameter in the above.
3.2.6-Handle design
The lever can be operated either a single person or by two persons. The maximum force in order
to operate the lever may be taken as average 400N and the length of handle as 300mm.in case of
the lever is operated by two persons, the maximum force of operation will be doubled and length
of handle may be taken as 500mm.the handle is covered in a pipe to prevent handle scoring. The
end of the shaft is usually square so that the lever may be easily fixed of removed. The length (L)
is usually from 400- 450mm and the height of the shaft center line from the ground is usually
1000mm. in order o design such levers:
 The diameter of the handle (d) is obtained from the bending consideration. It is
assumed that the effort (P) applied on the handle acts at of its length (l).
Therefore maximum bending moment,
(1)

And section modulus, (2)
Therefore resisting moment (3)
Where, = permissible bending stress for the material of the handle.
Equating equation (1) and (3) then can be determining the value of diameter of the
handle (d). The cross section of the lever arm is usually uniform thickness throughout.
The width of the lever arm is tapered from the boss to handle. The arm is subjected to
constant twisting moment and varying bending moment near the boss.
That is maximum bending moment
To combine the bending and twisting of rectangular section to enable us to find
equivalent bending and twisting with sufficient accuracy,
(4)
Now by using the relation ⁄ we can find t and B. the width of the lever arm near the
boss is taken as twice the thickness (
After finding the value of t and B, the induced bending stress may be checked which should not
exceed the permissible value.
Knowing the value of the maximum principal or shear stress induced may be checked
by using the following relation:
Maximum principal stress, [ √ ]
Maximum shear stress, √
And bending moment on the journal of the shaft,
( )
Where, x = distance from the end of boss to the center of journal
Now determine equivalent twisting moment,
√ = √
We know that equivalent twisting moment,

Then from the expression, can be determine the diameter of the journal (D).
The material used for handle should have the following properties;
 It should have high strength.
 It should have good Mach inability.
 It should have good heat treatment properties.
 It should have high wear resistant properties. Then it is better to we select the material for
this situation ASTM50 steel.
. The following parameters are available:
Length of the handle (l) =300mm
Length of the lever (L) =400mm
For the selected material
The lever operated by single person.
The force (p) applied at2/3 of handle length.
1. Diameter of the handle (d)
Therefore ( )
Section modules (Z)
Resisting bending moment (M)
Nmm
From the above equation we have
√
2. Cross section of the lever arm:
t=thickness of the lever arm in mm
w=width of the lever arm near to the boss in mm

Therefore the maximum bending moment
Section modules
We know that the bending stress
√ =
After this we can get the bending moment and section modules
Induced bending stress
The induced bending stress is within the safe limit.
Twisting moment:
3. Diameter of the journal:

Since the journal of the shaft subjected to twisting and bending moment therefore the
diameter is obtained from the equivalent equation of twisting moment
d=diameter of the journal
√
√
Equivalent twisting moment
√ =27mm
Result: the dimension of handle is already determined in order to change the direction of panel.
3.2.7- Design of frame link and supporting pole
The frame material made from stainless steel for stability and rigidity, this structure is seated
6000mm length of panel and 1000mm height and 9mm width. Each frame jointed from the base
by welding the frame supports the entire weight of panel can be support.
E=210Gpa, SY=250Mpa
A buckling response leads to instability and collapse of the members. It is the ability of a
structure to support a given load without sudden change in configuration.
For the failure occurs by yielding or crushing without buckling, at stress above proportional
limit.
Le=2000/2=1000mm both ends of the frame are fixed from appendix A5
√ √

=250.014Mpa
Radius of gyration
√ √ √ √
a=b
⁄
=
= (1)
= (2)
Therefore the supporting pole is must be 38mm by 38mm.
3.2.8 - Design of support link
Material selection:-due to the nature of the load applied on the material we select high strength
low alloy steel which have the following properties.
345Mpa
=485Mpa E=200Gpa

Compressive stress ( = or
To calculate buckling load of the link, both ends are considered fixed. Therefore effective length
of the link is
This links are carrying the load of panel and their components which used to support.
Total weight ( acting on the link is equal to:
Working stress per unit area =1923MN/11.04mm2
The Rankin constant a=1/7500=0.0001333
Buckling load
Moment of inertia for rectangular section
According to Rankin formula K=√
√

( )
(1)
And the other,
( )
(2)
Equating the equations
Assume to be the thickness of the supporting link is quarter of the width which is equal to 1mm
thick.
3.3-Pumps selection
Pumps are used the transfer fluids through their piping circuits. The pumps associated with the
collector fluid will be exposed to the highest temperature and the greatest pressure. To minimize
the high temperature in this loop, the pump is paced in the pipe going to the collectors. But even
here there will be short term periods when the pump is handling temperatures greater than the
design collector discharge temperature .Such a time is when the hot heat transfer fluid has been
forced out of the collector in to the recapture tank due to stagnation. If using an anti-freeze as the
collector heat transfer fluid, the pump components will need to be compatible with the water.
These considerations will affect the materials used in the construction of the pump. The pump
will also need to operate through flow range that is designed for the system. In some solar
thermal systems, the heat transfer fluid flow is slowed when the solar radiation is not at its peak.
At this lower flow the pump must still provide the required pressure to obtain fluid movement
through the pipe system. Having clean fluid strainers /filters, a minimum of valves, and properly
operating sensors will aid in keeping the system pressure drop as low as possible. In large
systems, the piping system flow is modeled to define the pump pressure needed for proper
operation. It is important to take in to account that water mixtures have a different viscosity than
water alone. The manufacturer of the heat transfer of the heat transfer medium should provide
the necessary data. The energy needed to pump the heat transfer fluid is considered parasitic
energy; it must be kept as low as possible. The pump should thus not be oversized.
Fluid pumps
The type pump to be used is center type that is used in building heating systems. If the loss of
fluid to the environment is a concern a seal-less magnetic drive centrifugal pump should be
considered. The pump components (seals, gaskets, bearings, etc) must be able to with stand hot
temperatures that could reach may be reach for short periods. Basically, three types of pumps are
available:
Constant flow pumps
Electronic pressure c pumps controlled (variable flow)
High efficient pressure controlled pumps (variable).
If water is the circulated fluid and the system open to the atmosphere or the water is potable then
the pump wilted components should be made from stainless steel or broth to minimize corrosion.

Solar collector pumps should be placed in locations where leakage would not cause serious
damage
Controls: the controller controls the flow of the heat transfer fluid in the collectors by modifying
the pump operation. Normally the pump is just turn on/off in small systems. The most common
pump controller used in solar thermal system is the differential controller. This controller require
two different temperature settings, one for ON (upper band) and one for OFF (Lowe band).The
system temperatures are measured on an absorber in a collector (usually one whose flow is a
short distance to the storage tank) and in the storage tank (near the tank outlet to the collectors)
or in these discharge pipe and adjacent to the tank. If the collector temperature exceeds the
storage tank temperature plus the upper band the pump will turn on. If the collector temperature
drops below the store temperature plus the lower band the pump will turn on. If the collector
temperature drop blows the store temperature plus the lower band the pump will turn off. Some
pump – controller combinations offer different power settings (often step-wise) to be able to
much the mass flow rat with the amount of solar radiation available. This limits the temperature
increase in the solar circuit and prevents unnecessary pumping. More advanced controller offer
additional functionality insulation and heat measurement, data logging, error diagnostics, and
auxiliary heaters (collectors) regulation, and a graphical user inter face.
Method of leak detection: on completion of the piping system, it should be pressure
testing for leaks. All piping systems should always include a pressure gauge (digital or dial) for
monitoring the fluid pressure. The system should be filled with water and put under pressure of
1.5 times the operating pressure for a minimum of two hours, while the pressure is monitor and
the distribution is inspected for leaks. The leak inspection should be completed before installing
any piping insulation.
3.4 General maintenance
 Check the solar collectors and stricture components for any damage. Note
location of panel glazing or broken evacuated tubes needing replacement. Note
that tubing containing heat transfer fluid is in good condition
 Check tightness of mounting connectors. Repair any bent or corroded mounting
components.
 Drain energy storage tank for sediment removal.
 Check condition of heat transfer fluid.
 Determine if any new objects, such as vegetation growth, are causing shading of
the array and remove them if possible.
 Clean outer surface of collector array annually with plain water or mild
dishwashing detergent. Do not use brushes, any types of solvents, abrasives, or
harsh detergents.
 Check all connecting piping for leaks. Repair any damaged components.

 Check plumbing for signs of corrosion
 Check condition of corrosion inhibitors in heat transfer fluids and the state of
sacrificial anodes in the system.
 Observe that the collector heat transfer fluid pump is running on a sunny day and
not at night.
 Use insolation meter to measure incident sun light and simultaneously observe
temperature and energy output values given by the system controller. Compare
the valves with original efficiency of system.
 Check status indicators provided by system controller compare indicators with
measured values.
 Document all operation and maintenance activities in a work book available to all
service personnel.
 Check proper position of all valves.
 Flush entire piping system to remove mineral deposits every ten years.
3.5-Manufacturing process
3.5.1 Welding and Fabrication:
Aluminum welding is performed with gas metal arc welding (MIG) similar to the use of the
process with steel; the only other process used with aluminum is gas tungsten arc welding (TIG)
which is used for thinner material. The lower elastic modules of aluminum compared to steel has
benefits and drawbacks. Residual stress from welding is lower, but the stress that does occur,
because greater distortion and buckling of thin structure is still limited today, even with very
involved finite element analysis. The prediction models rely to an extent on experimental data.
And there is far less data for aluminum, so that the state of the art in prediction of distortion in
aluminum has not advanced. Rule of thumbs for such thing as weld sequencing are available, but
experienced with fabricated similar structure is the best guide today. Because of the greater
distortion that generally occur in aluminum structure, fabrication tolerance are that for similar
steel structure the lower elastic modules of aluminum compared to steel has benefits and
drawbacks. Residual stress from welding is lower, but the stress that does occurs because greater
distortion in steel structure is still limited today, even with very involved finite element analysis.
The prediction models rely to an extent on experimental data, and there is far less data for
aluminum, so the state of the art in prediction of distortion in aluminum has not advanced. Rule
thumb for such things as weld sequence are available, but experience with fabricating similar
structure is the best guide today. Because of the greater distortion that generally occurs in
aluminum structure in aluminum structure, fabrication tolerance is greater than for similar steel
structure.
3.5.2The spur gear manufacturing process:

Spur gears are the most common type of gear, and are used in all industries. The term spur gears
is used to describe cylindrical gears with straight teeth cut parallel to the axis of the gear, and are
mounted on parallel shafts to transfer power from one shaft to the other. Spur gears give a high
degree of efficiency, and due to having straight teeth produce no end thrust. They give excellent
results at slow to medium peripheral speeds, but tend to be noisy at high speeds due to them
having a parallel line of contact, although profile grinding will greatly improve noise
characteristics.
There are 3 main manufacturing processes for generating spur gears, and these are planning,
shaping and hobbling. A gear planer utilizes a rack cutter, shaping a circular disc cutter and
hobbling a cylindrical hob tool. At Bell Gears we have a variety of machinery which covers all
of these processes.

3.6 Total Cost Analysis
Table 4 cost analysis
materials Part name Density(kg/m3
) Volume(m3
) Material
weight(kg)
Price /gram
(Birr)
Price
per
unit
copper Collector
tube
8900 0.00028 2.3 0.25 500
glass Solar
collector
2500 0.076 19 1.98 22578
aluminum Water
storage tank
2700 0.0358 96.66 0.658 6367
steel absorber 7850 0.00195 15.30.4314 0.44 660
Carbon steel shaft 7850 0.0231 181.33 0.00663 1200
Cast iron gear 7250 0.00316 22.9.2 0.0022 500
Cast steel Supporting
pole
491.4 0,0028 1.418 0.2142 300
ASTM50steel handle 7850 0.00146 11.46 0.03 200
Total 32305ETB

Figure 18 Isometric assembly drawing
Figure 19 assembly drawing

Over all dimension and materials:
Table 5 over all dimension
S/NO Part name materials Quantity Dimension
1 Solar
collector
Polly glass 6 height length width remark
1900 1000 4
2 Support pole stainless steel 2 2000 30 30
3 Spur gear cast-iron 1 30 384 30
4 Pinion gear Cast iron 1 30 96
5 handle ASTM50 1 300 400 27
6 Pump - 1 selection
7 Water storage
tank
aluminum 2 2500 1950 12
8 valve - 2 selection
9 controllers - 1 selection
10 shaft SAE1050
steel
1 70 6000

4: CONCLUSION AND RECOMMENDATION
4.1-Conclusion
The goal of this project is to design a cost effective solar power water heater in preference to
other types of water heating systems. The design satisfies the cause of use and intuitive
requirements as shown through the design parts, specifications, features of designed and selected
equipments. The solar water heater panels were designed within manual tracking system in order
to allow maximum traction. The system satisfies all the objectives; hence the design is able to
deliver 7500liters of water for the cafeteria. This time sustainable energy is the main concern of
our world, so this design depends on design parameters including sustainable energy. Generally
our design satisfies the main goal of this project that is to design a cost effective and efficient
solar power water heater in preferable to the fire wood for KIOT student cafeteria.

4.2-Recommendation
So far we did our strained efforts on the project; there are still a lot to be improved in the design
of different parts. Site temperature, environmental conditions must e studies in details rather than
taking latitudinal and longitudinal values. That is a location must be identify well exposed no
shading (no shadows nearby buildings, trees, and others), plus the components and sensors of
solar water heater must be locked inside the hot water tank to reduce heat losses through the pipe
line. And, the tracking system is adjusted for being operated manually. Therefore it needs an
attendant to do so with the movement of sun; this may take the design quality down therefore we
recommended someone in the future to do studies to make the tracking system automatic
allowing better efficiency for the solar panels. Finally we would like to say someone to improve
all listed problem with advanced systems, KIOT to allow us to employ the first geometric of
solar water heater for student‟s cafeteria.

APPENDIX A STANARRD TABLE FOR DESIGN
Appendix A1 selection criterion of solar collector
Type of
material
Size Power Weight Cost Efficiency
Mono crystal
line
1m×1.9m Above 285w Optimum Optimum Medium and
high
Poly crystal
line
1m×1m Power less 40 pound Simple cost Lower
amorphous Depend on
the condition
Lower Medium Undefined 30 % (lower)
Appendix A2 material specification of solar collector
s/no Collector type Overall
efficiency
a1[W/(k.m2
)] a2
1 High performing
evacuated tube
collector (ETC)
0.75 1.0 0.005
2 High performing
flat plate
collector(FPC)
0.8 3.0 0.008
3 Medium
performing FPC
0.75 4.0 0.010

Appendix A3 experimental value of site temperature
Month Maximum temperature Minimum temperature
January 25.6 9.9
February 26.0 13.3
March 27.7 13.6
April 28.7 14.5
May 28.3 14.8
June 30.9 15.2
July 29.6 15.3
August 27.1 14.9
September 26.7 14
October 25.7 11.5
November 25.8 10.6
December 24.8 7.9
Appendix-A4 densities of different materials
Material Mass density(kg/m3)
Cast iron 7250
Wrought iron 7780
Steel 7810
Brass 8450
Copper 8900
Cobalt 8850
Bronze 8730
Tungsten 19300
Aluminum 2700
Lead 11400
Nickel 8900
Cast steel 491.4

Appendix – A5 thickness specification of storage tank
Diameter of tank Minimum thickness[t]
0.9m or less 6mm
Above 0.9 m and up to 1.35m 7.5mm
Above 1.35m up to 1.8m 9mm
Over 1.8m 12mm
Appendix – A6 properties of carbon steel grade
Indian standard designation Ultimate tensile strength,
(map)
Yield strength,(map)
40 c 8
45 c 8
50 c 8
50 c 12
560-670
610-700
640-760
700Min
320
350
370
390
Appendix – A7 standard value of equivalent length
s/No. End condition Relation between equivalent
length(Le)and actual length(L)
1 Both ends hinged Le = L
2 Both end fixed Le =
3 One end fixed and other
hinged
Le =
√
4 One end fixed and other end
free
Le = 2L

Appendix B part drawings
Appendix B1 solar collector panel

Appendix B2 water storage tank

Appendix 3 collector tube

Appendixes B4 handle

Appendix B5 spur and pinion gear design

Appendix B6 shaft
Appendix B7 supporting frame and mounted supporting poles

Reference
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