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Recently, there was a demand to find unconventional solutions for energy. Therefore, the investigations concerned to discover alternative fuel such as compressed natural gas, methanol, biodiesel, etc. In this study, a new alternative fuel in vehicle engines is evaluated and, the reduction of the emitted pollution as a result of using this fuel. In addition, the effect of biodiesel fuel (cottonseed...
The presented paper deals with simulation of a detailed model of wind conversion chain based on permanent synchronous machine. In this paper, wind energy is transformed to a mechanical energy by blade and turbine and turbine, which is transmitted to the shaft of the PMSM, that's was modeled then simuled with MATLAB. Also the out put voltage of this wind conversion chain is controlled by a PI regulator...
This works deals with the study and control of output voltage of a conversion chain based on wind conversion using a PI controller integrated into the system, and presents a mathematical model that allows the simulation of all under the Matlab environment. This with the implementation of the direct torque control DTC for the synchronous machine supplied with a rectifier installed on the output of...
This paper presents results obtained from monitoring a 3.9 kWp grid connected photovoltaic system installed on a flat roof of a laboratory building of FECE in Prishtina, Kosovo (Latitude 42.6667°N and longitude 21.1667°E). System was monitored between the May 2013 to November 2013, and all the electricity generated was fed into the low voltage network supply to the building. This system consists of...
Characterization of photovoltaic panel is important to predict its long-term performance. In this study a test facility has been designed and built to trace the IV curve of four photovoltaic panels. The system contains four subsystems, Four PV panels containing temperature and radiation sensors (external elements), IV tracer with panel switcher, data acquisition system, and computer command and treatment...
Flange height is between the geometric futures of the diffuser that contributes efficiently in improving diffuser performances. Results obtained from experimental data show a critical ratio (Flange height/Inlet section diffuser diameter = 0.2) has been found. Beyond this value, due to the remoteness of vortices from the flange, the flange height seems to be without significant effect on increasing...
This work presents the results and analysis of a power quality measurement realized in a large scale PV system. The evaluated system is a 1 MVA centralized PV plant with different technologies of photovoltaic panels and inverters. The power quality measurement was made in accordance with the Brazilian and international power quality regulation. The magnitudes measured were voltage, current, power,...
With the aim of arising the temperature of water, the solar still will be augmented with a solar collector or/and a solar reflector. This work is an attempt to assess the changes made in the thermal balance when we added a solar collector and a solar reflector to a simple solar still. After having established the thermal balances of the various solar systems studied at instationary regime, the differential...
The wind, among renewable energies, can play a important role for the water supply, irrigation of agricultural land and the generation of electrical energy. In fact, groundwater can be pumped using wind energy. This paper presents the perspectives of wind mechanical pumping in eight synoptic sites distributed at the Tunisian south. Map of Water Resources showed that Tunisia south is characterized...
Wind energy is one of the fastest growing renewable energy resources worldwide. The estimation of the wind resources depends on the atmospheric circulation data retrieved from meteorological observations or regional climate models outputs. These models provide weather and climate data over specific domains and over time periods where few or no observations exist. In this work we evaluate the sensitivity...
In this paper, a new two stage vapor compression refrigeration cycle is investigated. At this cycle, both the vapor compression and expansion processes are done at two stages. This system, designed to offer two cold temperatures in order to store two categories of food, works with R134a as a refrigerant. To enhance its performance, a heat exchanger and a flash separator are integrated in this cycle...
A 3D numerical model is proposed in this paper to simulate unsteady cavitating flows aroud hydrofoil NACA66mod. The Reynolds-averaged Navier-Stokes equations are solved for the mixture of liquid and vapor, which is considered as a single fluid with variable density. This variable is expressed as function of the vapor volume fraction. The closure of this variable is provided by the transport equation...
Renewable energy generation (Wind, solar …) is rising rapidly around the world, for the most part to reduce the negative environmental impacts (effect of carbon emissions), attributable to consumption of fossil fuels. Energy storage is being today feasible with some kind of variable renewable electricity sources such as the Pumped Hydraulic Storage (PHS). This paper focuses on the applicability of...
Estimation of wind characteristics is considered as the first essential step to evaluate a wind energy project based on information about all aspects of the implementation and operation of the project. It's therefore necessary to have detailed knowledge of the wind to select the suitable wind turbine for a certain zone and also to estimate its performance accurately. Various parameters need to be...
Novel wind tunnel with conical and elevation structure is proposed and demonstrated for power generation. The tunnel is evaluated and characterized using sucking fan which is placed at the front end to simulate available wind in the atmosphere. A wind turbine is placed at the back end of the tunnel to generate electricity. The tunnel structure is made up from galvanized aluminum with square front...
In this research paper, an attempt has been made to come across the effect of multiple glazing covers on the efficiency of a solar thermal collector. This experimental investigation was carried out on an active solar energy demonstration system (ET 200), illuminated with a halogen lamp. Three commercial glass panes of 3 mm thickness, having the same dimensions as that of the apparatus glazing, were...
Concentrating solar thermal power, more commonly referred to as CSP, concentrate direct solar radiation to heat a fluid and produce steam or vapor of another working fluid. Collectors, whether for parabolic trough, power tower, Fresnel mirror, or solar dish, comprise up to 40% of the total system costs for CSP collectors' technologies. Reducing the cost of CSP systems involves improved collector designs...
Nowadays, a lot of attention in the smart grids' development is devoted to methods of estimation of the energy demand by taking into account the behavior of network participants (single prosumers and groups). However, these methods take an advantage from an analysis of the ex-post data, and as such they use mainly the data covering the energy consumption with no additional information about prosumers...
The use of solar energy in sunny countries in rural areas is an effective way to overcome the lack and the difficulty to supply into electrical energy. It is therefore important and necessary to exploit this natural and clean resource. Among the methods of thermal conversion of solar energy, solar refrigeration is the most suitable application for the storage of foodstuffs and pharmaceutical products...
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