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ЭНЕРГЕТИКА И АВТОМАТИКА
1.10. EXPERIMENTAL RESULTS AUTOMATIC SYSTEM OF TRACKING FOR INDEPENDENT CONCENTRATORS OF SUNLIGHT
Akhadov Jobir Zamirovich, PhD, Senior research of the Institute of Material Sciences, SPA «Physics-Sun» Academy of Science of Uzbekistan and International Solar Energy Institute, email: ahadovj@mail.ru
Abdurahmanov Abdujabbar Abdurakhmanovich, Professor, Head of Laboratory of Big Solar Furnace Institute of Material Sciences, SPA «Physics-Sun» Academy of Science of Uzbekistan, email: aabdujabbar46@mail.ru
Saydumarov Ilhomjon Miralimovich, PhD, Head of the chair of «Operation of the radio electric equipment of aircraft and airports» of the Tashkent State Technical University, Tashkent, Uzbekistan, email: saidilh@yandex.ru
Abstract: The new type of the solar gauge working by means of photo diodes SV-256 is developed. Thus accuracy of management of solar concentrators reception processes heated pair for development electricity and heat, and also hydrogen in a focal zone of concentrating systems completely provides. It was shown, that the system of tracking developed by us heliostat for trajectory the Sun has high accuracy. Linear changes of the center of a stain in dynamics makes only 2 mm that corresponds 30-80 angle to seconds. Such accuracy of tracking allows carrying out high-temperature researches in a focal zone of the concentrator.
Index terms: Solar Power Installation, Automatic System of Tracking, Solar Energy, the Solar Independent Combined Installation.
1.10. ЭКСПЕРИМЕНТАЛЬНЫЕ РЕЗУЛЬТАТЫ ИСПЫТАНИЙ АВТОМАТИЧЕСКОЙ СИСТЕМЫ СЛЕЖЕНИЯ ДЛЯ АВТОНОМНЫХ КОНЦЕНТРАТОРОВ СОЛНЕЧНОГО ИЗЛУЧЕНИЯ
Ахадов Жобир Замирович, канд. техн. наук, старший научный сотрудник института Материаловедения НПО «Физика-Солнце» Академия Наук Республики Узбекистан и Международный институт Солнечной энергии. E-mail: ahadovj@mail.ru
Абдурахманов Абдужаббар Абдурахманович, доктор технических наук, Зав. лаборатории Больших Солнечных Установок института Материаловедения НПО «Физика-Солнце» Академия Наук Республики Узбекистан. E-mail: aabdujabbar46@mail.ru
Сайдумаров Илхомжон Миралимович, канд. физ.-мат. наук, зав. кафедры «Эксплуатация радиоэлектрооборудования летательных аппаратов и аэропортов» Ташкентского Технического Государственного Университета. E-mail: saidilh@yandex.ru
Аннотация: Разработан новый тип солнечного датчика работающего с помощью фотодиодов СВ-256. При этом точность управления солнечных концентраторов полностью обеспечивает процессы получения перегретого пара для выработка электричество и тепло, а также водорода в фокальной зоне концентрирующих систем.
Ключевые слова: Солнечная энергетическая установка, автоматическая система слежения, солнечная энергия, автономная комбинированная солнечная установка.
Akhadov J. Z., Abdurahmanov A. A., Saydumarov I. M.
1. MIRROR CONCENTRATING SYSTEMS
One of problems of creation of concentrators of sunlight this maintenance of their orientation after visible movement of the Sun. Generally the problem of orientation of mirror concentrating systems (MCS) consists in maintenance of its such spatial position at which reflected from MCS beams constantly move on the receiver (see fig. 1).
Figure 1. The basic scheme system of tracking of independent solar installations (the Sun- the Concentrator - the Receiver)
1.1. Tracking Systems
Till now are practically investigated accuracy of tracking MCS by means of optical gauges, including the size "tolerance zones" or "a dead zone", together with accuracy the tracking's provided with optical gauges, and also as a whole is investigated dynamics of change of corners of orientation MCS (including heliostat) within day and year, especially in the presence of overcast [1].
The problem consists that such solar gauges already grows old and not where in the world is not issued such gauges. Proceeding from it we developed new systems of tracking for solar installations with accuracy 1 angle/min. Such system of tracking copes very conveniently and easily.
There are the following primary goals of orientation connected with two basic operating modes of system MCS - the receiver. In the first scheme the receiver is established on MCS and moves together with it - the mode of direct tracking and the second scheme the receiver is not connected with MCS and is usually motionless - so-called heliostat operating mode MCS/1/.
The literature analysis [2-3] shows, that generally for creation of control systems by orientation (tracking systems) both on the first and on the second following data are necessary for schemes:
1. The equation of movement of object (in this case the equation of visible movement of the Sun);
2. A range kinematic, dynamic, mechanical and accuracy characteristics of the rotary devices depending on their constructive scheme;
3. Actually knowledge demanded accuracy and dynamic characteristics of control system MCS.
Thus tracking systems can be divided on automatic and the programs the operated. The automated control system of tracking to classify to various signs: to destination, accuracy, a scope, an action principle etc.
The basic problem consists that for individual using of independent solar installations is necessary simple system of tracking of the concentrator for the sun that not knowing what automatics and the computer any person operated system. For this purpose, the automated control systems of tracking of independent solar concentrators have developed the new scheme system of tracking by means of photo diodes SV-256 (fig. 2).
■L \ i
Figure 2. Developed the block of management of orientations MCS and developed solar the gauge on the basis of photo diodes SV-256
For maintenance specified above functions of management by orientation MCS should include following subsystems: the solar gauge, the executive mechanism providing turns MCS and including a reducer, a drive (electric motor); a control system including the block actually of management and the converter of signals, carrying out
transformation and giving of signals on intensifying and executive mechanisms.
2. SOLAR GAUGE
The primary goal which the solar gauge as it has been specified above should carry out is binding MCS and its axes of rotation to local geographical to ordinates concerning which the law of movement of object of tracking (in our case of the Sun) can be usually certain. Developed by us the solar gauge consists of 4 photo diodes which is established one plate and divided into 4 blocks.
2.1. Solar Installations
The developed automatic system of tracking of concentrators about accuracy 1 angle/min. also it is conducted tests in 1500 and 5000 W them solar installations. In further the developed system will be used in parabolic cylinder the concentrator the size 10x10m (fig.3).
Figure 3. A photo of the developed concentrator in diameter of 6 m
The offered automated control system of tracking of independent solar concentrators with the new scheme of systems of tracking by means of photo diodes SV-256 has accuracy 30-80 angle to seconds, tests are spent to 1,5 and 5 kW solar installations.
2.2. Models
The solar power plant thermal capacity 1500 W
consists from heliostatsand the sunlight concentrator. Heliostat directs solar beams on the concentrator in parallel in horizontal an axis. The parabolic concentrator reflects solar beams in focus. The tracking system is necessary for maintenance in focus of the concentrator of a stable power stream of a solar energy heliostat for the sun with high accuracy. Power light exposure of a focal zone of the concentrator it is possible allows to synthesize materials, and also to receive overheated steam for reception electric and thermal energy [4].
If the receiver has rather big thermal inertia its thermal mode will be close to stationary and development of energy or converter efficiency will be defined by an average for the period arrival of energy [5].
In a dynamic mode an average for the period t value of density of energy Eef in a focal point A on an element of surface N, equally
Ef (A, N ) = - ft Ep(A, N)dz (1) T0
where, Ee - density of a direct solar stream.
With certain degree of approach the average for the period in a dynamic mode can be considered a system condition as some static condition in aim position, but with the seeming, effective parameter of accuracy heft. In effect, almost in all cases of natural research of solar power plants their power parameters resulted frequently without references to accuracy of tracking and considered as objective (that is received at exact by adjust on a source), carry actually effective (dynamic) character.
On fig. 4. a, b are shown experimental works a deviation of the center of a stain from a focal point Ain working conditions of system of tracking heliostat on a day trajectory of the Sun. As shows the analysis at such accuracy of tracking heliostat on the Sun trajectory, the deviation of the center of a stain from a focal point essentially does not change (fig. 5).
Akhadov J. Z., Abdurahmanov A. A., Saydumarov I. M.
a)
b)
Figure 4. Changes of a stain in a focal zone 1,5 kW the solar furnace.
Figure 5. Dependence of an angular deviation of a
stain on a corner of disclosing of the concentrator at various linear deviations
3. CONCLUSIONS
Experimental and settlement works have shown that the system of tracking developed by us heliostat for trajectory the Sun has high accuracy (figs 4 and 5). Linear changes of the center of a stain in dynamics makes only 2 mm that corresponds 30 - 80 angle to seconds. Such accuracy of tracking allows carrying out high-temperature researches in a focal zone of the concentrator.
Список литературы:
1. Umarov G. J., Zakhidov R. A, Vajner A. A., the Theory and calculation application solar energy concentrating systems. Tashkent, the FAN, 1977, 144с.
2. Zakhidov R. A. Mirror systems of concentration of radiant energy. Tashkent "FAN", 1986. 173с.
3. A control system heliostats. The Sokolov of L. В, Nikolaev of Century П, Semushkin J. M, Sementsov L. V, Novoselova N. G, Cedar B.M. А.с. 1147901, the USSR. Order on 28.03.83, № 3568568/24-06, In B.I, 1985, № 12.
4. J. Z. Akhadov, A. A. Abdurahmanov, A. L. Aguera, A. A. Abdu-muminov, B. Yokubov. Researches and creations independent combined solar power for reception of hydrogen, electric and thermal energy. European Association for the Development of
Renewable Energies, Environment and Power Quality (EA4EPQ). 2012y
5. A. A. Abdurahmanov, Sh. I. Klichev, J. Z. Akhadov, M. A. Mamatkosimov. The technique of a settlement-experimental estimation of characteristics of mirror concentrating systems. Applied Solar energy. Tashkent, 2005. - №1.-pp.62-66.
РЕЦЕНЗИЯ
В статье приведена результаты исследования системы автоматического слежения за положением солнечных концентраторов с точностью 30-80 угл.сек. и результаты испытаний них на солнечных установках мощностью 1500 и 5000 Вт. Такая точность управления солнечными концентраторами обеспечивает процессы получения перегретого пара для выработки электричества и тепла, а также водорода в фокальной зоне автономных концентрирующих систем.
Одна из проблем создания концентраторов солнечного излучения это обеспечение их ориентации вслед за видимым движением Солнца. В общем случае задача ориентации зеркально концентрирующих систем (ЗКС) заключается в обеспечении такого её пространственного положения, при котором отраженные от ЗКС лучи постоянно подаются на приемник. Проблема состоит в том, что такие солнечные датчики уже устарели и их выпуск прекращен.
Системы слежения можно разделить на две группы: автоматические и программно-управляемые. Автоматизированная система управления слежения классифицируется по различным признакам:
- по назначению,
- точности,
- области применения,
- принципу действия и т. д.
Основная проблема заключается в том, что для индивидуального использования автономных солнечных установок необходима простая и надежная система слежения концентратора за солнцем. В связи с этим, авторами разработана новая схема система слежения с помощью фотодиодов СВ-256. Основная задача, которую должен выполнять солнечный датчик, это привязка зеркально концентрирующий систем (ЗКС) и её оси вращения к местным географическим координатам.
Разработанный авторами солнечный датчик состоит из 4 фотодиодов, которые установлены одну пластинку и разделены на 4 блока.
Экспериментальные работы показали, что разработанная система слежения гелиостата за траекторией Солнца имеет высокую точность. Линейное изменения центра пятна в динамике составляет всего 2 мм, что соответствует 30-80 угл. секундам. Такая точность системы слежения позволяет обеспечить непрерывную работу всех типов автономных солнечных концентраторов.
Работа выполнена на высоком научно-техническом уровне и может быть опубликована в открытой печати.
Рецензент, д-р техн. наук
Рахимов Р.Х.
