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.
Due to the lack of fossil fuels and its products quantities,
obtaining difficulties, and its global and local high price. It has
become necessary to look for other means and methods of
providing electrical energy far from fossil resources or suppo
rt
the existing ones.
The study is focused on renewable energy sources, especially
solar energy (both thermal and photovoltaic), wind energy as
well as biomass which are sufficiently available in the Syrian
Arab Republic.
Utilizing the renewable energy sources is the main focus of
this study, in which the investment in the field of photovoltaic
energy and economic efficiency will be reviewed and
compared to generating electricity using diesel generators.
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.
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.
The research aims to optimize the investment in solar cooling process using two
models of vessels (clay- mineral).The study was conducted at the site of Tartous in the
month (the fourth - fifth - sixth) years (2013) and that the fruits of the tomat
o study, she
stated that the pottery is causing a drop in temperature between )4-6( degrees Celsius, and
that the metal causes the low temperature range between (3-5 ) degrees Celsius although
the fruits of tomatoes preserved pottery vessels have not undergone any damage of its
structure or texture during the period of conservation (27 days) compared to the control
which is exposed to damage during the (12 days) .
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.
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%.
Three identical gable-even-span greenhouses were designed, constructed
and installed at the Agricultural and Veterinary Research Station of King
Faisal University in order to produce cucumbers during the winter season.
These experimental greenhous
es were covered by ٠,٨mm thick fiberglass
reinforced plastic. Two different solar heating systems were designed, built and
employed to heat the ambient air temperature inside the greenhouses. The
design of the first one was a surface heating system suspended and fixed on the
southern side of the gable roof of one greenhouse. The second solar heating
system was a solar panel, which was designed, built and situated outside of the
other greenhouse.
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.).
In this research a study effect of absorbed surface shape for solar air collector
(Flat V-Corrugated ,Sinusoidal Wave-Corrugated ,Rectangular-Corrugated) titled to the horizontal by an angle(30) on forced heat transfer and skin friction coefficient
by Fluent Numerical Program at constant solar heat flax (530W/m2) with Reynold’s number (5000≤Re≤8000). The government equation (mass, momentum and energy) are using Finite Volume by (Fluent 6.3) software for considering steady state, two dimensional and turbulent flow. The results show that the different between inlet and outlet air temperature is(13.65oC) and best heat transfer coefficient enhancement is(63%) for (V-Corrugated plate) compared with the flat plate at (Re=8000). Also the results show that the maximum skin friction coefficient is occurred at (V-Corrugated) Cf=0.22 at (Re=8000).
