Heat Collection Tracker System for Solar Thermal Applications
Abdelrasoul jabar Alzubaidi1 ,
1 Sudan university of science and technology- Engineering Collage-School of
electronics- Khartoum- Sudan . [email protected]
Abstract : This paper investigates the
effect of using a continuous operation
two-axes tracking on the solar heat
energy collection. This heat-collection
sun tracking with LDR (light
dependent resistor) sensors installed on
the lens was used to control the
tracking path of the sun with
programming method of a closed loop
control system. The control hardware
was connected to a computer through
(X-bee wireless module) and it also
can monitor the whole tracking process
information on a computer screen. An
experimental study was performed to
investigate the effect of using two-axes
tracking on the solar heat energy
collected. The results indicate that sun
tracking systems are being increasingly
employed to enhance the efficiency of
heat collection by polar-axis tracking
of the sun.
KEYWORDS: solar energy , computer
, X-Bee module , solar cells , LDR
sensors.
I. INTRODUCTION
The alternative for the locations that go
through a shortage of electricity
production due to numerous factor is
the use of solar energy .This study
aimed to reduce the consumption of
electrical energy used for the purpose
of obtaining hot water in the winter
season where the temperature may
drops below zero degrees Celsius on
some days. The study demonstrated the
feasibility of obtaining temperatures in
these systems of up to 90 degrees
Celsius even in the coldest days. The
cost of the design is relatively low and
easy which makes every house in the
city able to used it.
There are many types of solar
collectors such as glazed, unglazed,
and selective surface coated solar
collector. A solar thermal collector is a
special heat exchanger that transforms
solar radiative energy into heat. During
the last two decades a number of
researchers have worked on developing
new and more efficient solar collector
or improving existing ones . The
integral collector/storage solar water
heater (ICSSWH) is quite possibly the
most well known and simplest solar
water heating system. It is developed
from early systems . It was originally
produced in the 1970's but is still in
use now. It is simple, efficient and
cheap to build. Simply painting a tank
black, putting it in a big crate, and
insulate it all around except one side
that needs to be covered by glass or
plastic. To be viable economically, the
system has evolved to incorporate new
Abdelrasoul Jabar Alzubaidi, Int.J.Computer Technology & Applications,Vol 6 (2),295-302
IJCTA | Mar-Apr 2015 Available [email protected]
295
ISSN:2229-6093
and novel methods of maximizing
solar radiation collection whilst
minimizing thermal loss. All it takes is
a tank, insulation and sun. The water is
collected, stored and warmed all in one
container. The advantages to the
integral collector/storage system are
low cost, no pumps or controls ,
simple, and Long-lasting. The
disadvantages are water doesn't get
really hot and discontinuity of the
optimal use of the hot water produced.
II. APPROCH
Over the years, several researchers
have studied the solar tracking systems
with different modes and
electromechanical module to improve
the efficiency of solar systems. The
design of tracker was based on some
criteria: low cost, easy maintenance,
modular, low energy consumption, and
easy adjustment in case of different
location . From previous studies, there
are two tracking types to track the sun.
One is active type and the other is
passive type . In a passive system the
tracker follows the sun from east to
west without using any type of electric
motor to power the movement, but the
active type needs motor, control IC,
track procedure, and detect
components responding to the solar
direction.
Active tracking systems are powered
by small electric motors and require
some type of control module to direct
them. The controller had two modes
that can identify the active tracker to
the location of the sun. One is electro
optical sensors such as solar cell or
LDR (Light Dependent Resistance) or
photodiodes based on the structure of
trackers .The situation of tracking
under cloudy conditions, when the sun
is not visible, a computing program
calculates the position of the sun and
takes control of the movement, until
the detector can sense the sun again.
III. SYSTEM DESIGN AND
COMPONENTS
First of all, it is necessary to analyze
the system operation. According to the
analysis procedures, the system
operations can be transformed from
local mode of operation into remote
mode of operation. The designed
circuit for remote mode must optimize
the capture of the solar energy . An
ASK technology is implemented for
the remote control . Figure (1) below
shows the block diagram for the
remote control system design by using
X-Bee transmitter / receiver modules.
Abdelrasoul Jabar Alzubaidi, Int.J.Computer Technology & Applications,Vol 6 (2),295-302
IJCTA | Mar-Apr 2015 Available [email protected]
296
ISSN:2229-6093
Figure (1) block diagram of the remote control system
The system components in the design contains two parts. The first part is the
hardware and the second part is the software. The details of the hardware and the
software are:
A . HARDWARE :
The hardware components for the design are :
Solar dish :
It is used to capture the solar energy. Figure (2) shows a sketch of a solar dish.
.
Figure (2) solar dish power collector
Com
puter
X-BEE
X-BEE
Micro
control
ler
inter
face
Stepper -
x
Stepper
-y inter
face
LDR LCD
Abdelrasoul Jabar Alzubaidi, Int.J.Computer Technology & Applications,Vol 6 (2),295-302
IJCTA | Mar-Apr 2015 Available [email protected]
297
ISSN:2229-6093
Computer :
To program the microcontroller , an IBM PC or compatible computer system
is used.
Microcontrollers :
Microcontrollers are frequently used devices in embedded electronic systems
in which the applications varies from computing, calculating, smart decision-making
capabilities, and processing the data. Atmega 32 microcontroller is used in the
design.
X-Bee :
X-Bee module is a device used to communicate via wireless network, it utilizes the
IEEE 802.15.4 protocol which implements the entire features to ensure data delivery
and integrity. Figure (3) shows the (X-Bee Pro) module and Pin outs.
Figure (3) X-Bee Pro modules and Pin outs
ULN 2803 Darlington IC:
The ULN2803A is a high-voltage, high-current Darlington transistor array. The
device consists of eight NPN Darlington pairs that feature high-voltage outputs with
common-cathode clamp diodes for switching inductive loads. The collector-current
rating of each Darlington pair is 500 mA. The Darlington pairs may be connected in
parallel for higher current capability.
Abdelrasoul Jabar Alzubaidi, Int.J.Computer Technology & Applications,Vol 6 (2),295-302
IJCTA | Mar-Apr 2015 Available [email protected]
298
ISSN:2229-6093
They are used to track the sun in X and Y coordinates.
Lab link cable:
The lab link cable is used to connect the computer to the interface circuit and for
downloading the ( .hex) file into the microcontroller.
LCD :
It is used for display.
B. SOFTWARE:
Turbo C++ programming language is used in the computer . For the microcontroller ,
Bascom programming language is used.
IV . ALGORITHM
The proposed computer algorithm includes a sequence of steps for the operation of
the solar collection system . Pressing key (0) from the computer initializes the system
.Pressing key (*) ends the program. Equation (1) indicates the position of the stepper
motors for maximum capture of solar energy.
(Solar energy) max = (X coordinates )max + (Y coordinates )max …………….. (1)
The microcontroller algorithm for the maximum solar energy collection contains two
subroutines as follows :
The first subroutine performs scanning of the stepper motors platform in the X and Y
coordinates in order to specify the X-axis and Y-axis locations for capturing
maximum solar energy. The X-axis stepper motor searches for (180 degrees) , while
the Y-axis stepper motor searches for (90 degrees). These assumptions are relevant
for tracking the solar energy .Equation (2) gives the number of steps for the X-axis
stepper motor and Equation (3) gives the number of steps for the Y-axis stepper
motor .
X-axis stepper motor steps = 180 degree / 1.8 degree = 100 steps ……(2)
Y-axis stepper motor steps = 90 degree / 1.8 degree = 50 steps ……(3)
Stepper motors :
Abdelrasoul Jabar Alzubaidi, Int.J.Computer Technology & Applications,Vol 6 (2),295-302
IJCTA | Mar-Apr 2015 Available [email protected]
299
ISSN:2229-6093
The second subroutine performs positioning of the X and Y stepper motors to the X-
axis and Y-axis locations for capturing maximum solar energy .The microcontroller
algorithm is as follows:
Start
Authorization code:
--- Enter authorization code from the keyboard.
--- If the cod is correct , then go to Initialization.
---If the cod is incorrect , then display „ access is denied‟ and go to authorization code.
Initialization:
... Let X-axis =100.
... Let Y-axis =50.
… Let LDR = 0.
System operation:
--- If the (key pressed = 0) , then go to search for maximum solar energy.
… Go to system operation.
Search for maximum solar energy :
--- Call scan solar cell subroutine.
… Decrement Y-axis.
…If (Y- axis = 0 ) then call set maximum platform position subroutine.
… Go to search for maximum solar energy .
--- If the (key pressed = *), then go to end of the program.
--- Go to system operation.
End.
Scan solar cell subroutine : … Activate winding-1 of X stepper motor.
….. Delay 1 second.
…. Decrement X-axis .
… If ( captured LDR > LDR ) then LDR = captured LDR and ( X-axis = X-axis , Y-axis = Y-axis ) .
… Activate winding-2 of stepper motor.
….. Delay 1 second.
…. Decrement X-axis .
… If ( captured LDR > LDR ) then LDR = captured LDR and ( X-axis = X-axis, Y-axis = Y-axis ) .
.
… Activate winding-3 of stepper motor.
….. Delay 1 second.
…. Decrement X-axis
… If ( captured LDR > LDR ) then LDR = captured LDR and ( X-axis = X-axis , Y-axis = Y-axis).
… Activate winding-4 of stepper motor.
Abdelrasoul Jabar Alzubaidi, Int.J.Computer Technology & Applications,Vol 6 (2),295-302
IJCTA | Mar-Apr 2015 Available [email protected]
300
ISSN:2229-6093
….. Delay 1 second.
…. Decrement X-axis
… If ( captured LDR > LDR ) then LDR = captured LDR and ( X-axis = X-axis , Y-axis = Y-axis ).
… If (X- axis = 0 ) then go to terminate X-axis.
Go to scan solar cell.
Terminate X-axis:
Return
Set maximum platform position subroutine:
… Locate X-stepper motor to position X-axis.
… Locate Y-stepper motor to position Y-axis.
Return
V. RESULTS
There is no doubt that the experiment
is dealing with laboratory models,
which can be generalized to become
available in real application form. In
this study mainly a water solar
collectors for domestic heating and hot
water production is considered. The
choice of the optimal collector depends
on the temperature level required by
the specific application and on the
climatic conditions of the site of
installation. The results also indicated
that the best time to obtain the largest
solar irradiation power is during
10:00 –16:00 in the experiment location area.
VI. CONCLUSION
In this paper an experimental study is
performed to investigate the effect of a
two-axis tracking on the solar heat
energy collected for thermal
application. The hardware and
software elements of the two-axes sun
tracking system were designed and
constructed. According to the results of
the measurements performed in the
present study, it can be concluded that
proper LDR sensor will increase the
accuracy of tracking sun‟s radiation. In
order to totally collect the solar thermal
energy of the sunlight, it is very
important to let the concentrative
sunlight to totally illuminate on the
heating element.
Abdelrasoul Jabar Alzubaidi, Int.J.Computer Technology & Applications,Vol 6 (2),295-302
IJCTA | Mar-Apr 2015 Available [email protected]
301
ISSN:2229-6093
References
[1] P. Roth, A. Georgiev, and H.
Boudinov, “Cheap two axis sun
following device,” Energy Conversion
and Management, vol. 46, no. 7-8, pp.
1179–1192, 2005. View at Publisher ·
View at Google Scholar · View at
Scopus
[2] M. J. Clifford and D. Eastwood,
“Design of a novel passive solar
tracker,” Solar Energy, vol. 77, no. 3,
pp. 269–280, 2004. View at Publisher ·
View at Google Scholar · View at
Scopus.
[3] P. Roth, A. Georgiev, and H.
Boudinov, “Design and construction of
a system for sun-tracking,” Renewable
Energy, vol. 29, no. 3, pp. 393–402,
2004. View at Publisher · View at
Google Scholar · View at Scopus
[4] W. A. Lynch and Z. M. Salameh,
“Simple electro-optically controlled
dual-axis sun tracker,” Solar Energy,
vol. 45, no. 2, pp. 65–69, 1990. View
at Scopus
[5] V. Poulek and M. Libra, “New
solar tracker,” Solar Energy Materials
and Solar Cells, vol. 51, no. 2, pp.
113–120, 1998. View at Scopus
[6] G. C. Bakos, “Design and
construction of a two-axis Sun tracking
system for parabolic trough collector
(PTC) efficiency improvement,”
Renewable Energy, vol. 31, no. 15, pp.
2411–2421, 2006. View at Publisher ·
View at Google Scholar · View at
Scopus
[7] H. Mousazadeh, A. Keyhani, A.
Javadi, H. Mobli, K. Abrinia, and A.
Sharifi, “A review of principle and
sun-tracking methods for maximizing
solar systems output,” Renewable and
Sustainable Energy Reviews, vol. 13,
no. 8, pp. 1800–1818, 2009. View at
Publisher · View at Google Scholar ·
View at Scopus
Abdelrasoul Jabar Alzubaidi, Int.J.Computer Technology & Applications,Vol 6 (2),295-302
IJCTA | Mar-Apr 2015 Available [email protected]
302
ISSN:2229-6093