This research aims to study the effect of adding alloying elements and heat treatment
of Zinc metal on solar energy absorbing , nine alloys ingots were manufactured by
changing the percentages of added Aluminum and Copper on the pure Zinc, and thes
e
ratios of Aluminum were : (10% , 20% , 30% , 40 % , 50%) to demonstrate the effect of
adding Aluminum to Zinc metal on solar energy absorbing , and ratios of copper were :
(20% , 40%) , as well as we prepare two pure zinc samples with 99.2% of purity , one
was rapidly cooled and the other slowly cooled , to demonstrate the effect of heat treatment
on solar energy absorbing .
In order to measure the solar energy absorbing for prepared samples , we
manufactured a device depends on the methods of heat exchange between solar radiation
and the surface exposed to radiation .
The obtained results showed that adding Aluminum and Copper to the pure Zinc
caused a decrease in solar energy absorbing .
As well as increasing the percentages of adding Aluminum and Copper to the pure
Zinc caused a gradually decrease in solar energy absorbing .
comparing the absorbing of pure zinc samples, one was rapidly cooled and the other
slowly cooled , the results showed that the sample was rapidly cooled was better than the
sample slowly cooled on solar energy absorbing .
We offer in this research, theory study using a modeling tool for the
possibility of improving the performance of solar pumping system
of rivers using submersible centrifugal pump with variable speed
and moving solar panels controlled by logical microcontroller
programmer (plc.).
The research problem is neglecting urban policies and construction
systems to use renewable energy within urban fabric, in particular
solar energy. And it aims to study the relationship between urban
morphology and solar energy potential and its r
ole in the
establishment of more suitable cities in terms of energy, and thus
guide the planning policies to increase utilization of solar energy
within cities.
In this study، a traditional air source heat pump was modified by adding secondary
evaporator within hot water tank which acted as a water heat source of the heat pump. We
made the heat pump to run alternatively either using surrounding air heat or
water heat
gained from solar power.
We have done experiments during five months starting in December of 2014 until
April 2015. Temperature and pressure were measured at specific points of the cycle. Then
we defined the enthalpy at each point for both cycles using EES software (which is a
software to simulate thermodynamic elements)، and calculated the amounts of heat gained
in the evaporator، heat charged from the condenser، compressor work، coefficient of
performance ، and electrical power consumed by the compressor.
Then we made a compare between the two cycles and found that the improvement
ratio in of the modified cycle to the traditional cycle was 77.07%، and the reduction
ratio in electrical power consumed by the compressor of the modified cycle was 33.54%.
The aim of current work is to develop a mathematical model designed by Rabl for
compound parabolic collector (CPC) using tubular receiver instead of the flat receiver. The
simulation was carried out for reflection of direct and indirect solar radia
tion incident on
the compound parabolic collector.
The equations were evaluated using analytical geometry for calculating the Cartesian
coordinates of the reflecting surface, then the falling and reflected rays on the detector
were calculated. A MATLAB program was developed to generate the data and print the
reflected rays through the use of 10000 rays at random position according to the random
Monte Carlo simulation for each angle of the rays. We found that the optimum value of
half acceptance angle is 35.
This investigation showed that the efficiency of compound parabolic collector
decreases with increasing the radius and length of receiver at the same inlet temperature of
working fluid. Also showed that the efficiency of compound parabolic collector with
tubular receiver is higher than collector with flat receiver at the same conditions.
Solar Energy and Hydrogen are possible replacement options for fossil fuel, But a major drawback to the full implementation of solar energy, in particular photovoltaic (PV), is the lowering of conversion efficiency of PV cells due to elevated cell t
emperatures while in operation. Also, hydrogen must be produced in gaseous or liquid form before it can be used as fuel; but its‟ present major conversion process produces an abundance of carbon dioxide which is harming the environment through global warming. In search of resolutions to these issues, this research investigated the application of Thermal Management to Photovoltaic (PV) modules in an attempt to reverse the effects of elevated cell temperature. The investigation also examined the effects of the thermally managed PV module to a Electrolyzer (Hydrogen Generator) for the production of hydrogen gas in an environmentally friendly way.
The results of the investigation showed that the cooling system stopped the cell temperature from rising, reversed the negative effects on conversion efficiency, and increased the power output of the module by as much as 33%. The results also showed that the thermally managed PV module when coupled to the hydrogen generator impacted positively with an appreciablely increase of up to 26% in hydrogen gas production.
This paper introduces an integrated study concerning the technical and economical sides for supplying the electrical loads of a rural isolated society or small isolated village represented in Almazraa village relevant to Nawa Town located at the nort
h western of Daraa Governorate at a distance of about 30[Km]. The followed methodology of this study aims at the comparison between two states required electrical loads according to special scenario of each state, the first scenario represents the feeding of special loads of a daily lifetime activity performed by the inhabitants of this village representing a case of typical rural society, and the second scenario adding the loads of irrigation of surrounding agricultural lands to the first scenario. For supplying the required loads then making a comparison between two choices, the first choice is the usage of solar cells as a renewable energy source, while the second choice is the usage of diesel generation units as a traditional energy source. This paper included the preparation of the mathematical model of previous system then to determine the volume of this system for each of the two cases of loads and the previous two choices of energy sources. The preparation of computer programs of previous study because of the easiness of projecting them two similar cases. The research also included an economical study of the previous cases then coming through them into the computation of fixed cost or construction cost, running cost and the annual cost and then estimating the production cost of Kilo Watt-hour and to identify the more economically feasible of choice. Then to complete this study by focusing on the volume mass of contamination wastes caused by the daily work of diesel units and presentation of the economical importance for the usage of solar cells especially in the isolated areas and in the rural and agricultural societies as economical choice and without an environmental damaging wastes.
This research aims to study the effect of the tilt angle of PV panels on the daily discharge a water pump powered by solar energy, and to determine the optimal tilt of these panels during summer months in the Syrian coast.
The results demonstrated t
hat the change of the tilt angle of PV panels from (25˚) to (35.5˚), has no effect on the curve of the solar radiation intensity and flow rate. However the resulting impact was represented by low amount of solar energy falling onto PV panels, resulting in a reduction in hydraulic energy of the pump and consequently low flow rate per day. The study showed that the amount of water flow rate at the two angels (25˚ and 22˚) for the tilt of panels was close, with preference for the angle (22˚). Reduction of water amount from one month to another during the months (June, July, August) didn't exceed (2.5%), while it was (7.5%) in September. At angle (35.5˚), water amount was approximately constant during June, July and August, while it decreased by (6%) in September. Flowing water largely decreased at angle (35.5˚) in comparison with the two angles (25˚and 22˚), so the reduction was (13, 12, 9 and 7.5%), respectively in June, July, August and September.
The rising in the world’s population leads automatically to the rising in water demand. As a consequence
the lack of drinking water increases Currently, approximately 1.2 billion people globally (one-sixth of the
world’s population) do not have acc
ess to adequate clean water. Since a large part of the world’s
population is concentrated in coastal areas, the desalination of seawater seems to be a promising solution,
especially in our Arab world. An innovative stand-alone solar desalination system could be used to
produce drinking water from seawater or any brackish water sources. The great advantage of such a
system is that it combines efficient desalination technology, reverse osmosis, with a renewable energy
source. The main goal is to improve the technical feasibility of such systems, There are many advantages
of this coupling with RE resources ; first of all we separate the drinking water from the electricity grid
and its faults, save burning the fossil fuel and its emissions, and provide fresh water to remote
communities that do not have sufficient traditional energy sources. But as we see in this study we don’t
have economic benefit; because these projects depend on the electricity cost in each country and the
location and its solar specifications.
We designed and implemented a small laboratorial model for PV-RO (Photo-Voltaic Powered Reverse
Osmosis) to recognize the performance for seawater and brackish water, we faced some problems such as
embargo on Syria; so have done project using affordable local potentialities, but we craved to keep the
principle of operation, so we make it for the tap water which close to brackish.
The electrical performance of the PV modules can be severely affected by operating temperature of silicon cells due to properties of the crystalline silicon used; the energy generated from these cells decreases with their high temperatures. To reduce
this decline in energy, the PV modules use cooling water by placing a tube containing many regular holes on the top end of the module, and water flows on the surface freely in several flows. So, with flow rate (4.224 l/min.m2), module temperature decreases up to (20C°); the record of increased value of electrical yield over the whole day is about (12.8%). and efficiency rises (from 8.31% to 9.62%) of (1.31%). With Flow rate (3.167 l/min.m2), temperature of module decreases up to (18C°); the record of increased value of electrical yield is about (9.8%), and efficiency rises by (1.03%). But with flow rate (2.112 l/min.m2), temperature of module decreases up to (15.5C°); the record of increased value of electrical yield is about (7.8%), and efficiency rises by (0.83%). Furthermore, flow of water on the surface of PV module reduces the reflection losses because the refractive index of water with (1.3) is intermediate between air (1) and glass (1.5). In addition, the surface of module remains clean.
