Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year.
Solar technology offers great potential in terms of supplying the world’s energy needs. However, its current contribution to the world is still limited. The main factor is related to high initial cost of building the system. This paper will provide an up-to-date review of solar concentrators and their benefits to make solar technology affordable. It will also analyse on some of the existing solar concentrators used in the solar technology for the past four decades. The design and performance of each concentrator will be explained and compared.
This project is about conducting an experimental study on solar heated pipe with parabolic trough reflector. The effect of different parameters on the solar heated pipe will be analyzed for optimum design. Design and construction of the experimental setup for the above study is discussed.
Different parameters which are analyses as follows: Size and thickness of the pipe, size of the casing, flow rate of the fluid, type of fluid, angle of inclination of rim, design parameters etc. These variables will be compared by the efficiency of the solar heated pipe.
Solar technology offers great potential in terms of supplying the world’s energy needs. However, its current contribution to the world is still limited. The main factor is related to high initial cost of building the system. This paper will provide an up-to-date review of solar concentrators and their benefits to make solar technology affordable. It will also analyse on some of the existing solar concentrators used in the solar technology for the past four decades. The design and performance of each concentrator will be explained and compared.
This project is about conducting an experimental study on solar heated pipe with parabolic trough reflector. The effect of different parameters on the solar heated pipe will be analyzed for optimum design. Design and construction of the experimental setup for the above study is discussed.
Different parameters which are analyses as follows: Size and thickness of the pipe, size of the casing, flow rate of the fluid, type of fluid, angle of inclination of rim, design parameters etc. These variables will be compared by the efficiency of the solar heated pipe.
Improvements in efficiency of solar parabolic troughIOSR Journals
Solar energy is primary source of all type of energy which is present in nature i.e. all the energy
derived from it. So, direct utilization of solar energy into useful energy is important. There are so many solar
thermal equipments in which concentrating type collector heated the fluid up to 100 to 4000C. It is employed for
a variety of applications such as power generation, industrial steam generation and hot water production.
Parabolic trough collector is preferred for steam generation because high temperatures can achieve.
Cylindrical parabolic trough type collector consists of selective concentrator and a receiver tube. The
selective cover system prevents the heat loss (convective and radiative) from the receiver tube and improves the
performance of solar parabolic trough. Also evacuated chamber is created to reduce the loss of heat and reduce
the corrosion of concentrator surface. Tracking system is embedded in the solar parabolic trough for tracking
the sun energy movement.
This report presents the evaluation of solar insolation in terms of monthly average hourly global
radiation in Patna on 10th April, 2013. On the basis of this solar energy flux, comparative study of the
instantaneous efficiency of solar parabolic trough is done. Here four different types of cover system are
mathematically analyzed. (i) Single glass cover on receiver (ii) Double glass cover on receiver (iii) Single glass
cover on aperture (iv)Double glass cover on aperture. This report contains many graphs to illustrate the effect
on instantaneous efficiency on variation of primary parameter. With the help of MATLAB R201a software
mathematical calculation is obtained.
Solar to energy presentation geofrey yatorGeofrey Yator
Solar to energy conversion.The definition,need for,technologies and the Future of solar energy in the planet earth.
The article is presented by Geofrey Kibiwott yator University of Eldoret.
Abstract:
Concentrated Solar Power (CSP) technology is one of the most promising candidate for mitigating the future energy crisis. The extracted power from CSP technology is very clean, reliable and environmental friendly. An overview of CSP technologies like Parabolic Trough, Solar Tower, Parabolic Dish, Linear Fresnel technology have been described in this paper. Comparison among these technologies has been illustrated in this work. For extenuating the present power crisis in Bangladesh CSP technology has great opportunities, since the average Direct Normal Irradiance (DNI) in Bangladesh is 4-6.5 KWh/m 2 which is suitable for all types of CSP technology. Suitable locations for different CSP plants in Bangladesh are also proposed on the basis of efficiency, required area and amount of DNI received.
DOI: 10.1109/ECACE.2017.7913020
Application of Solar Energy - Environmental Studies BBA (Honors)Samuel pongen
Presentation on Solar Energy application as per prescribed textbook Richard T. Wright – Environmental Science
Most relevant for Christ University BBA (honors)
Solar Energy as an Alternative Energy than the Conventional Means of Electric...Ali Alhelal
Abstract: This study aims to show the feasibility of using solar power in Iraq as an alternative source of power generation. This research investigated the profits of using solar power economically and environmentally. Also, it addressed a set of important charts such as generated power, oil production, the amount of gas that used in the power plant, the average of delivered electricity hours, and CO2 emissions. Ten locations are chosen as the best places according to their total annual solar radiation and each location is assumed to have a 10 MW solar park. The results showed saving about 676,000 USD daily (based on 52 USD per barrel) from petrol can be used to generate electricity from the conventional means, offsetting over 200,000 metric tons of carbon dioxide equivalent emissions annually, and around 111 job will be created during the construction stage of each 10 MW.
Improvements in efficiency of solar parabolic troughIOSR Journals
Solar energy is primary source of all type of energy which is present in nature i.e. all the energy
derived from it. So, direct utilization of solar energy into useful energy is important. There are so many solar
thermal equipments in which concentrating type collector heated the fluid up to 100 to 4000C. It is employed for
a variety of applications such as power generation, industrial steam generation and hot water production.
Parabolic trough collector is preferred for steam generation because high temperatures can achieve.
Cylindrical parabolic trough type collector consists of selective concentrator and a receiver tube. The
selective cover system prevents the heat loss (convective and radiative) from the receiver tube and improves the
performance of solar parabolic trough. Also evacuated chamber is created to reduce the loss of heat and reduce
the corrosion of concentrator surface. Tracking system is embedded in the solar parabolic trough for tracking
the sun energy movement.
This report presents the evaluation of solar insolation in terms of monthly average hourly global
radiation in Patna on 10th April, 2013. On the basis of this solar energy flux, comparative study of the
instantaneous efficiency of solar parabolic trough is done. Here four different types of cover system are
mathematically analyzed. (i) Single glass cover on receiver (ii) Double glass cover on receiver (iii) Single glass
cover on aperture (iv)Double glass cover on aperture. This report contains many graphs to illustrate the effect
on instantaneous efficiency on variation of primary parameter. With the help of MATLAB R201a software
mathematical calculation is obtained.
Solar to energy presentation geofrey yatorGeofrey Yator
Solar to energy conversion.The definition,need for,technologies and the Future of solar energy in the planet earth.
The article is presented by Geofrey Kibiwott yator University of Eldoret.
Abstract:
Concentrated Solar Power (CSP) technology is one of the most promising candidate for mitigating the future energy crisis. The extracted power from CSP technology is very clean, reliable and environmental friendly. An overview of CSP technologies like Parabolic Trough, Solar Tower, Parabolic Dish, Linear Fresnel technology have been described in this paper. Comparison among these technologies has been illustrated in this work. For extenuating the present power crisis in Bangladesh CSP technology has great opportunities, since the average Direct Normal Irradiance (DNI) in Bangladesh is 4-6.5 KWh/m 2 which is suitable for all types of CSP technology. Suitable locations for different CSP plants in Bangladesh are also proposed on the basis of efficiency, required area and amount of DNI received.
DOI: 10.1109/ECACE.2017.7913020
Application of Solar Energy - Environmental Studies BBA (Honors)Samuel pongen
Presentation on Solar Energy application as per prescribed textbook Richard T. Wright – Environmental Science
Most relevant for Christ University BBA (honors)
Solar Energy as an Alternative Energy than the Conventional Means of Electric...Ali Alhelal
Abstract: This study aims to show the feasibility of using solar power in Iraq as an alternative source of power generation. This research investigated the profits of using solar power economically and environmentally. Also, it addressed a set of important charts such as generated power, oil production, the amount of gas that used in the power plant, the average of delivered electricity hours, and CO2 emissions. Ten locations are chosen as the best places according to their total annual solar radiation and each location is assumed to have a 10 MW solar park. The results showed saving about 676,000 USD daily (based on 52 USD per barrel) from petrol can be used to generate electricity from the conventional means, offsetting over 200,000 metric tons of carbon dioxide equivalent emissions annually, and around 111 job will be created during the construction stage of each 10 MW.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Similar to Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year.
Solar technology is the novel technology which uses the natural sunlight to produce
electricity. It uses the combination of three simple technologies that is turbine, vertical chimney of some
longer height and glass roof collector for absorbing the sun radiations. By proper utilization of this
technology the electricity can be generated in abidance and continuously for twenty four hours
throughout the year in county like India where there is sunlight almost for nine months in the major part
of the country. Much advancement has taken place in this technology for last three decades but the full
utilization of this technology has not taken place because of various aspects. This paper presents the
critical review of this important technology in the form of the advancements and developments taken
place in various parts of the world and analyzes its important aspects
The advent of micro grid has enticed a lot of interest in the research of distribution generation thereby bringing into existence an intelligent electrical generation networks. It ensures security, reliability, stability, and sustainable of energy. Micro grid may include both renewable and non-renewable energy sources. It has been proven to possess the promising potential of providing clean, efficient, and reliable power. The energy sources include solar photovoltaic, wind, fuel cell, micro turbine, bio- mass micro hydro. Various architecture of a micro grid are available and are developed the factors dependable upon availability of renewable resources, geographical location, load demand. For effective and efficient operation unlike main grid, it needs to employ special and control this is so because of combination of conventional and renewable energy sources.
Thermal Storage Comparison for Variable Basement Kinds of a Solar Chimney Pro...Waqas Tariq
A solar updraft tower power plant ‘solar tower’ is a solar thermal power plant utilizing a combination of solar air collector and central updraft tube to generate an induced convective flow which drives pressure staged turbines to generate electricity. The issue of this paper is to present practical results of prototype of a solar chimney with thermal mass, where the glass surface is replaced by transparence plastic cover. The study focused on chimney\'s basements kind effect on collected air temperatures. Three basements were used, concrete, black concrete and black pebbles basements. The study was conducted in Baghdad from August to November 2010. The results show that the best chimney efficiency attained was 49.7% for pebbles base. The highest collected air temperature reached was 49ºC when using the black pebbles basement also. Also, the maximum basement temperature measured was 59ºC for black pebbles. High increments in collected air temperatures were achieved compared to ambient air temperatures for the three basements kind. The highest temperature difference reached was 22ºC with the pebble ground.
Solar technology is the novel technology which uses the natural sunlight to produce
electricity. It uses the combination of three simple technologies that is turbine, vertical chimney of some
longer height and glass roof collector for absorbing the sun radiations. By proper utilization of this
technology the electricity can be generated in abidance and continuously for twenty four hours
throughout the year in county like India where there is sunlight almost for nine months in the major part
of the country. Much advancement has taken place in this technology for last three decades but the full
utilization of this technology has not taken place because of various aspects. This paper presents the
critical review of this important technology in the form of the advancements and developments taken
place in various parts of the world and analyzes its important aspects.
Modeling Of Flat Plate Collector by Using Hybrid TechniqueIOSR Journals
(SWH) are becoming increasingly attractive in sustainable development. Hence the Efforts continuously made here is to reduce their costs to make them more affordable. Solar energy has experienced a remarkable development in recent years because of cost reduction due to technological development as well as renewable energy scheme supported by the government. The process of using sun’s energy to heat water is not a new technology. (SWH) technology has improved a lot during the past century. The primary method of energy transport in solar energy from sun is electromagnetic radiation .This type of radiation coming from the Sun also depends on temperature. The Sun generates electromagnetic radiation in extensive span of wavelengths. However, most of the radiation is being sent out in the observable range due to its surface temperature. The amount of solar energy received in a particular region depends on the time of the day, the season of the year, the sky’s cloudiness, and how closeness of Earth’s equator. For modeling we utilized Genetic algorithm and for prediction we employed hybrid ABC and PSO techniques. Genetic algorithm is utilized in order to optimize the modeling technique by using the dataset collected.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
STUDY OF SOLAR THERMAL CAVITY RECEIVER FOR PARABOLIC CONCENTRATING COLLECTOR ijiert bestjournal
Energy is one of the building blocks of the country . The growth of the country has been fueled by chea p,abundant energy resources. Solar energy is a form of renewable ener gy which is available abundantly and collected unre servedly. The parabolic concentrator reflects the direct incident solar rad iation onto a receiver mounted above the dish at it s focal point. The conversion of concentrated solar radiation to heat takes place in receiver. The heat transfer characteristics of the receiver changes during the rotation of the receiver which affects thermal performance. The working temperature may also influence the ther mal performance and overall efficiency of the system. Thermal as well as optica l losses affect the performance of a solar paraboli c dish-cavity receiver system. The thermal losses of a solar cavity receiver include c onvective and radiative losses to the air in the ca vity and conductive heat loss through the insulation used behind the helical tube surface. Convective and radiative heat losses form the major constituents of the thermal losses. The convection heat loss from cavit y receiver in parabolic dish solar thermal power sy stem can significantly reduce the efficiency and consequently the cost effectiveness of the system. It is important to assess this heat loss and subsequently improve the thermal performance of the receiver.
International Journal of Computational Engineering Research(IJCER) ijceronline
nternational Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
MASTERS OF ENVIRONMENTAL ARCHITECTURE renewable energy systemsSamanth kumar
RENEWABLE ENERGY SYSTEMS,M.ARCH (ENVIRONMENTAL ARCHITECTURE) ANNA UNIVERSITY
UNIT I SOLAR ENERGY
➔ Solar radiation its measurements and prediction
➔ solar thermal flat plate collectors concentrating collectors –
applications - heating, cooling, desalination, power generation,drying, cooking etc
➔ principle of photovoltaic conversion of solar energy,
➔ types of solar cells and fabrication.
Photovoltaic applications:
➔ battery charger, domestic lighting, street lighting, and water pumping, power generation schemes.
UNIT II WIND ENERGY
➔ Atmospheric circulations and classification
➔ factors influencing wind , wind shear and turbulence
➔ wind speed monitoring
➔ Betz limit
➔ Aerodynamics of wind turbine rotor
➔ site selection
➔ Wind resource assessment
wind energy conversion devices
➔ classification,
➔ characteristics,
➔ applications.
➔ Hybrid systems - safety and environmental aspects.
UNIT III BIO-ENERGY
➔ Biomass resources and their classification
➔ chemical constituents
➔ physicochemical characteristics of biomass
➔ Biomass conversion processes
➔ Thermochemical conversion
➔ direct combustion,
➔ gasification,
➔ pyrolysis and liquefaction
➔ biochemical conversion
➔ Anaerobic digestion
➔ alcohol production from biomass
➔ chemical conversion process
➔ hydrolysis and hydrogenation
➔ Biogas - generation - types of biogas Plants- applications
UNIT IV HYDROGEN AND FUEL CELLS
➔ Thermodynamics and electrochemical principles
➔ asic design, types, and applications
➔ production methods
➔ Biophotolysis
➔ Hydrogen generation from algae biological pathways
➔ Storage gaseous
➔ cryogenic and metal hydride and transportation.
➔ Fuel cell
➔ principle of working
➔ various types
➔ construction and applications.
UNIT V OTHER TYPES OF ENERGY
➔ Ocean energy resources
➔ principles of ocean thermal energy conversion systems
➔ Ocean thermal power plants
➔ principles of ocean wave energy conversion
➔ tidal energy conversion
hydropower
➔ site selection, construction, environmental issues
Geothermal energy
➔ types of geothermal energy sites,
➔ site selection, and geothermal power plants.
This paper is all about how to install solar power stations in space and collecting solar energy with an efficiency of 95% (as proven). And then by using either microwaves or LASER, sending that energy to the power grids on earth and converting it into electricity.
Fabrication, Designing & Performance Analysis of Solar Parabolic TroughIJERA Editor
A parabolic trough solar collector uses a parabolic cylinder to reflect and concentrate sun radiations towards a receiver tube located at the focus line of the parabolic cylinder. The receiver absorbs the incoming radiations and transforms them into thermal energy, the latter being transported and collected by a fluid medium circulating within the receiver tube.This method of concentrated solar collection has the advantage of high efficiency and low cost, and can be used either for thermal energy collection, for generating electricity or for both, This paper focused on the fabrication and designing of solar parabolic trough, The designing of trough is depend upon the following parameters : Aperture of the concentrator , Inner diameter of absorber tube, Outer diameter of absorber tube, Inner diameter of glass tube, Outer diameter of glass tube, Length of parabolic trough, Concentration ratio, Collector aperture area, Specular reflectivity of concentrator, Glass cover transitivity for solar radiation, Absorber tube emissivity/emissivity, Intercept factor, Emissivity of absorber tube surface and Emissivity of glass. The performance analysis will be based on the Experimental data collection and calculations with reference to: Thermal performance calculations, Overall loss coefficient and heat correlations. Heat transfer coefficient on the inside surface of the absorber tube and Heat transfer coefficient between the absorber tube and the Cover.
Hybrid Photovoltaic and thermoelectric systems more effectively converts solar energy into electrical energy. Two sources of energy are used one of the energy is solar,that converts radiant light into electrical energy and heat energy which will convert heat into electricity.Photovoltaic cells and thermoelectric modules are used to capture and convert the energy into electricity.Furthermore solar-thermoelectric hybrid system is environmental friendly and has no harmful emissions.Solar-thermoelectric hybrid system increases the overall reliability without sacrificing the quality of power generated.In this paper an overview of the previous research and development of technological advancement in the solar-thermoelectric hybrid systems is presented.
Similar to Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. (20)
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year.
1. RESEARCH INVENTY: International Journal of Engineering and Science
ISSN: 2278-4721, Vol. 1, Issue 7 (November 2012), PP 56-61
www.researchinventy.com
The Effect of Variable Designs of the Central Receiver to Improve
the Solar Tower Efficiency
1
Miqdam Tariq Chaichan,2,Khalil Ibrahim Abaas,3,Hussain A
Kazem
1
(University of Technology, Baghdad, Iraq)
2
(Sohar University, Sohar, Oman)
Abstract - Concentrated solar power (CSP) is a method of electric generation fueled by the heat of the sun, an
endless source of clean, free energy. This study has focused on the feasibility of improving concentrating solar
power (CSP) plant efficiency, by manufacturing a diminished prototype. Three states were studied, coloring the
central target with a selective black color, fixing a reflector with arc form behind the target, and using these two
changes together. The results showed an improvement in the thermal storage varie d from month to month. The
maximum stored energy was gained at August with increments about 56.1%, 58.63%, 62.23 and 64.69% for
ordinary target, black painting, using reflector alone and black target with reflector together, respectively
compared with stored energy for March.
Keywords - Concentrated solar power, target, reflectors, stored energy, glass transmissivity
I. Introduction
The most important objectives of mankind these days are calming climate change and achieving
stabilization of greenhouse gas atmospheric concentrations. It will require large reductions in global emissions
of energy-related carbon dioxide emissions. It will be needed to developing and spreading new low-carbon
energy technologies [1]. Renewable energy sources offer a great potential fo r satisfying mankind’s energy needs
with neglig ible at mospheric CO2 emissions. They are also contrary to fossil fuels inexhaustible, and more
widely spread over the earth’s surface [2]. A wide nu mber of technologies and sources such as: bio mass,
hydraulics, ocean thermal energy, ocean tides and waves, solar heating and cooling, solar photovoltaic, solar
thermal electricity and wind are encompassing as renewable. Sources of renewable energy, such as solar and
wind power can generate more energy than the immediate demand. Large-scale production of solar electricity is
still technically and economically challenging. For solar energy, concentrating solar power (CSP) plants offer
ways to store this energy on a large scale, either thermally or as chemical fuels [3 & 4].Th is abundance of solar
energy makes concentrating solar power p lants an attractive alternative to traditional power plants, which burn
polluting fossil fuels, such as oil and coal. Fossil fuels also must be continually purchased and refined to u se.
Unlike tradit ional power plants, concentrating solar power systems provide an environmentally benign source of
energy, produce virtually no emissions, and consume no fuel other than sunlight.The only impact concentrating
solar power plants have on the environment is land use. Although the amount of land a concentrating solar
power plant occupies is larger than that of a fossil fuel p lant, both types use approximately the same amount of
land, because fossil fuel plants use additional land for mining as well as road building to reach the mines [5 &
6].Concentrating solar power systems generate electricity with heat. Concentrating solar collectors use mirrors
and lenses to concentrate and focus sunlight onto a thermal receiver, similar to a boiler tube. The receiver
absorbs and converts sunlight into heat. The heat is then transported to a steam generator or engine where it is
converted into electricity [7].There are three main types of concentrating solar power systems: parabolic
troughs, dish/engine systems, and central-receiver systems. These technologies can be used to generate
electricity for a variety of applications, ranging from remote power systems as small as a few kilowatts (kW) up
to grid-connected applications of 200-350 megawatts (MW) or more. A concentrating solar power system that
produces 350 MW of electricity displaces the energy equivalent of 2.3 million barrels of oil [8, 9 &10]Central
receiver (solar tower) systems use a circular array of large indiv idually -t racking mirrors (heliostats) to
concentrate the sunlight on a central receiver mounted on top of a tower, with heat transferred for power
generation through a choice of transfer media. After an intermed iate scaling up to 30 MW capacity, solar tower
developers now feel confident that grid-connected tower power plants can be built up to a capacity of 200 MW
56
2. The Effect of Variable Designs of the Central Receiver To…
solar-only units [11 & 12]. Use of thermal storages will increase their flexibility. Although central
receiver plants are considered to be further from co mmercialization than parabolic trough systems, solar towers
have good longer term prospects for high conversion efficiencies. Projects are in various stages of development
(fro m assessment to implementation) in Spain, South Africa and United States. In the future, central receiver
plant projects will benefit fro m similar cost reductions to those expected from parabolic trough plants. The
anticipated evolution of total electricity costs is that they will d rop to 5 cents/kWh in the mid to long term [13,
14 & 15].Iraq can be considered retarded in solar electric technology, because of the 100% dependence on fossil
fuels to produce electricity. Iraq is distinguished as a rich country in solar energy. The solar radiation available
for long times, in view of fact that Iraq has about 3600 sunn y hours per year [15 & 16]. Many valuables Iraqi
researches [17, 18, 19 & 20] clarified and confirmed the excellent activ ity of using sun in electrical power
generation. Iraq posses about 3000 sunny hour per year, and the hourly solar intensity at (Baghda d city as an
example) changes from 416 W/ m2 at Jan. to 833 W/ m2 at June [21 & 22]. The aim of this article is to study the
effect of variable designs of the central receiver (target) to improve the solar tower efficiency in Iraqi weathers.
II. EXPERIMENTAL S ETUP
The concentrated solar power plant is a solar optical concentration technology that uses a tower
receivers and extremely closely spaced reflectors to allow a high delivered output from an area of roof or
ground. It uses the annual solar beam radiat ion s triking an area of ground or roof that can be captured and
efficiently converted into useful electrical, thermal or cooling energy by using this technology .
A small prototype was manufactured with 4 rows of reflectors arranged in an arc form, the inner
diameter was 0.25 m, and the outer diameter was 1 m. The rows were d istributed as arcs with angle 150° at its
centre facing south. The heliostats made up from 2.0×2.0 cm2 mirrors. The first row heliostats were fixed 3 cm
height from the ground. The second heliostats row was fixed 4 cm height fro m the ground and departed from
first row 25 cm. The third heliostats row was fixed 6 cm height fro m the g round and departed fro m second row
25 cm. The forth heliostats row was fixed 8 cm height from the ground and depa rted from third ro w 25 cm.
These arrangements were taken to enhance reflected radiat ion aiming to target by mirrors.
Fig. 1, Photographic picture for the prototype assembly Fig. 2, Photographic picture for the prototype assembly
with black target and reflector
The aiming strategy in which successive rows of rays reflected fro m the mirrors are directed to the
receiver at different day time. Figs. 1 and 2 show the photographic pictures for the used assembly.The receiver
was made of a cylindrical wrought iron rod with 6 cm dia meter, 10 cm height and 2.8 kg mass. Target specific
heat is (Cp= 0.46kJ/kg °C), and its thermal conductivity is (k=59 W/ m °C) [24]. The target was put at a height
of 30 cm above ground level. It was covered by a glass cover box (25 cm×25 cm×25cm) to preserve all the
incident radiation, to prevent heat transfer by convection with ambient air, and to utilize the greenhous e effect.
Three calibrated thermocouples were used to measure the receiver temperature at any time. One thermocouple
was fixed at the top of the receiver, wh ile the second one was fixed at its bottom, and the last one was fixed in
the middle. Another target sample was prepared with the same specifications, except it was painted with a
selective black color, to study the effect of this painting on collecting efficiency. Fig. 2 represents the prototype
assembly. To collect the scattered radiations, an alu minum reflector was manufactured and prepared. It was
fixed behind the target rod departed 17.67 cm fro m it. Ground coverage can be increased to high levels by using
a reflector behind the receiver fro m the north side. This high ground coverage maximizes the c ollectable energy
fro m a given availab le roof or ground space. This reflector was prepared by covering a piece of alu minu m sheet
57
3. The Effect of Variable Designs of the Central Receiver To…
with alu minu m reflecting paper, and it was shaped as an arc. This reflecting arc was put (12 cm far
fro m the target assembly) facing the heliostats in such a manner that it reflected the incident rays coming fro m
the holists directly to the receiver. Fig 3 depicts the prototype assembly in case of black target with reflector.
A calibrated mercury thermo meter was used to read the ambient air temperature every hour. It was fixed in
shadow. The thermal efficiency of the system fro m inco ming solar beam was calculated using the following
equations:
The saved energy in target at each hour, Qact , is
Qact m C p T (kJ/hr) (1)
While the theoretical energy supposed to reach the target every hour fro m sun rise until sunset, Qtheo , is
calculated by the equation:
Qtheo I h r g ab Ap N (2)
The hourly efficiency h was calculated by the equation:
Qact
h (3)
Qtheo
Tests Procedure
The field was divided into three groups of mirro rs. The first gro up was aimed to the target every half an hour,
starting from the first morn ing up to eleven (11:00) o’clock. The second group was aimed to target every half an
hour starting fro m 11:00 o’clock until 14:00 o ’clock. The last group (which is on the right hand side of the
target) was aimed to the target every half an hour starting from 14:00 o’clock until sunset. This procedure was
used to get rid of the crit ical angles of sun radiations.
The prototype was examined for four cases:
1. The sun rays were aimed to target.
2. The sun rays were aimed to black colored target.
3. The sun rays were aimed to target with alu minum reflector behind it.
4. The sun rays were aimed to black target with alu minum reflector behind it.
The tests were conducted in AL Al-Shaab city north of Baghdad, Iraq. These tests were conducted starting from
March 2012 t ill end of August 2012. Every test was conducted in one shiny day starting from day break till
sunset.
III. RESULTS AND DISCUSS IONS
Fig’s (4, 5 & 6) reveal the measured temperature variation of th e four cases compared to air
temperature at Iraqi springtime (March, April and May). The air temperature rises during these months, the
maximu m temperature recorded for March was 20°C, for April was 27°C and for May was 33°C. The solar
intensity increased in these days causing the target temperature to be higher with days advancing. These figures
illustrate a fixed trend for measured temperatures variation. The lo wer measured temperature range was for the
ordinary target. The maximu m temperature range was for black target with reflector. Black target temperatures
exceeded the ordinary target temperatures, but it delayed from the ordinary target with reflector.These figures
show that coloring the target with selective black colo r increased the collected energ y due to black color
absorption. Adding reflector to the assembly increased the collected energy. The reflector acted as a gathering
element that collects the scattering radiation due to sun movement. So metimes, the solar energy use causes
instability in its readings due to the effect of clouds or dust. In April curves, it can be observed that black color
temperatures reduced and approached to ordinary target temperatures.
Fig. 3, Various target temperatures variations with time on Fig. 4, Various target temperatures variations with time
March on April
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4. The Effect of Variable Designs of the Central Receiver To…
Fig. 5, Various target temperatures variations with time on Fig. 6, Various target temperatures variations with time
May on June
The stored energy variation with day time for the four tested cases at Iraqi springtime (March, April &
May, respectively) is demonstrated in Fig’s (10, 11 & 12). These figures illustrate the sequence of stored energy
increments started by ordinary target, black target, target with reflector and the maximu m values always for
black target with reflector. This sequence is always correct, except for some variat ions. As an example in Fig.
10 at April tests, the black target curve comes near the target with reflector, also in May; the two curves
approached each others before sunset.
Fig. 7, Various target temperatures variations with time Fig. 8, Various target temperatures variations with time
on July on August
Fig’s (13, 14 & 15) man ifest the stored energy variations at day time at Iraqi su mmert ime (June, Ju ly &
August respectively). These curves clarify the former sequence without any approaches between the curves.
Also, these figures indicate that when the atmosphere is clear, then the black target with reflector will collect
and store the maximu m energy. The stability of solar intensity in Iraqi su mmert ime made the stored energy
curves taking this order, while the instability of solar intensity in Iraqi springtime caused the black target curve
approaching to target with reflector some times. The hourly incident radiation varies through daytime (where it
increases starting fro m daybreak till it reaches its maximu m value at noon, then it falls down after that). As a
result, the stored energy in the target took the same trend.
Fig. 9, Various targets stored energies variations Fig. 10, Various targets stored energies variations
with time on March with time on April
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5. The Effect of Variable Designs of the Central Receiver To…
Fig. 12, Various targets stored energies variations
Fig. 11, Various targets stored energies variations with with time on June
time on May
Fig. 13, Various targets stored energies variations with time Fig. 14, Various targets stored energies variations with time
on July on August
In view of the fact that the black target with reflector gains and stores the maximu m energy co mpared
to the other cases, the hourly efficiency for th is case was studied, as illustrated in figures 16 & 17 for Iraqi
spring and summert ime. The hourly efficiency increased from month to month and approached its maximu m
values at August. These figures show that the maximu m efficiencies will be reached at 12 AM and 1 PM, when
the solar intensity reached its maximu m values. These results clarify the possibility of improving the thermal
storage of solar station by using any of the tested cases.
Fig. 15, Various targets hourly efficiency variations Fig. 16, Various targets hourly efficiency variations
with time on springtime with time on summertime
IV. CONCLUS ION
A prototype of concentrated solar energy station was designed and constructed. The variation of the
target state was studied. Four cases were studied: using ordinary target, selective black colored target, ordinary
target with reflector and black colored target with reflector. The tests were conducted at Iraqi weathers in
springtime (March, April and May) and summert ime (June, July and August) 2012. The results clarified the
following conclusions:
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6. The Effect of Variable Designs of the Central Receiver To…
1. The Iraqi weathers are suitable for this type of systems. It is possible to attain high target temperatures
which can operate power station.
2. The maximu m temperatures and stored energies reached were at July and August; this indicates the
relationship between the solar intensity and resultant temperatures.
3. Coloring the target with a selective black co lor increased the target absorption which increases its
temperatures and stored energy.
4. Using a reflector behind the target to collect the scattered rays and reaming it to the target increased the
target temperature as well as it increased the stored energy.
5. The use of black colored target with reflector behind it gave the maximu m temperatures and stored energy
results, indicating its preference.
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NOMENCLATURE
m (target mass) = 2.8 kg
Cp (target specific heat (Cp) = 0.46 kJ/kg °C
T (temperature differences between every two hours from sun rise until sunset) = °C/hr
Ih solar intensity for every hour of the day, these data were taken from the Iraqi Metallurgy
Organization.
Ap single mirror area (m2 )
N Mirrors numbers
g The of transmissivity the glass surrounding the target =(90%)
r Mirrors reflection efficiency = (75%) [21]
ab Target absorptive = (0.8) [22]
h The hourly efficiency
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