Heat Collection Tracker System for Solar Thermal Applications

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1 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. rasoul46@live.com 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 295

2 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. 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 296

LCD LDR Com puter inter face X-BEE X-BEE Micro control ler inter face Stepper -y Stepper - x Figure (1) block diagram of the remote control system The system components in the design contains two

3 LCD LDR Com puter inter face X-BEE X-BEE Micro control ler inter face Stepper -y Stepper - x 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 297

4 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 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. 298

5 Stepper motors : 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) 299

6 ISSN: The second subroutine performs positioning of the X and Y stepper motors to the Xaxis 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 = 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. 300

7 ISSN: 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. 301

8 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 , 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 , 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 , 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 , 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 , View at Scopus [5] V. Poulek and M. Libra, New solar tracker, Solar Energy Materials and Solar Cells, vol. 51, no. 2, pp , 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 , View at Publisher View at Google Scholar View at Scopus 302

New Approach on Development a Dual Axis Solar Tracking Prototype

Wireless Engineering and Technology, 2016, 7, 1-11 Published Online January 2016 in SciRes. http://www.scirp.org/journal/wet http://dx.doi.org/10.4236/wet.2016.71001 New Approach on Development a Dual