Heat Collection Tracker System for Solar Thermal Applicationssustech.edu/staff_publications/20160119095040634.pdf · Abdelrasoul jabar Alzubaidi1, 1 Sudan university of science and

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]

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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.



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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



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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.



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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 :



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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.


…. Decrement X-axis .

… If ( captured LDR > LDR ) then LDR = captured LDR and ( X-axis = X-axis, Y-axis = Y-axis ) .

.



…. Decrement X-axis

… If ( captured LDR > LDR ) then LDR = captured LDR and ( X-axis = X-axis , Y-axis = Y-axis).




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…. 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.



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Documents

Heat Collection Tracker System for Solar Thermal Applicationssustech.edu/staff_publications/20160119095040634.pdf · Abdelrasoul jabar Alzubaidi1, 1 Sudan university of science and