IJE_Vol 06 N 01

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    Solar thermo-chemical process assisting a pressure oxidation process for co-production of electricity and metal
    (جامعة الوادي - university of el oued, 2021-06-03) Behar, Omar; Sbarbaro, Daniel; Moran, Luis
    The mining industry is looking at the use of solar energy to address issues related to highly variable energy prices, falling ore grades, and increasing concern about the industry’s carbon footprint. The pressure oxidation of ore sulfides is an economic alternative to the smelting process because it has the potential to reduce energy consumption and treat low-grade ores. In the pressure oxidation of ore sulfides, the purity and utilization of oxygen are key factors. Indeed, oxygen production and consumption constitute the major operating cost of the pressure oxidation process. Solar thermo-chemical looping processes have been identified as one of the most efficient pathways for the production and storage of oxygen. This study investigates the integration of a solar thermo-chemical looping process with a pressure oxidation process to treat ore sulfide and produce electricity. The analysis shows that the temperature of the cold storage tank has a strong influence on the performance of the complete system. The increase in the cold tank temperature results in a sharp decrease in the size of the receiver. This reduce the investment costs for both the solar receiver and the heliostat field. For the considered case, the useful heat of the solar receiver is 3.7 MWth when the cold tank temperature is set at 100°C. If the cold tank temperature is set at 400°C, the required useful solar heat is about 3.1 MWth and the nominal output of the gas turbine is 0.56 MWe. The analysis showed that about 80% of the useful solar heat can be used to generate oxygen when the temperature of the cold tank is as high as that of the reduction reaction.
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    Simulation of Night Cooling Through Natural Cross Ventilation using ANSYS (Fluent)
    (جامعة الوادي - university of el oued, 2021-05-29) Harnane, Yamina; Bouzid, Sihem; Berkane, Sonia; Brima , ,Abdelhafid; Kaddour, ,Abdelmadjid
    n this study, we carried out a numerical simulation using CFD code “Fluent 14.0” to quantify night ventilation due to convective and radiative phenomena with well-defined boundary conditions. The configuration is an open square cavity. Top & bottom walls are adiabatic, however, vertical walls represent the left/interior wall and right/external wall provided with a top and a bottom opening, at Tcold & Thot temperatures, respectively. The computational domain is two-dimensional with open boundary conditions of the local Bernoulli type. The fluid is incompressible with Boussinesq's approximation and flow regime is stationary turbulent with k-ε RNG model on a 200 * 240 mesh refined near the walls, (ΔT = 10 °C). The obtained results allowed flow dynamics & thermal characterization as well as cooling integral quantities calculation. Introduction of surface emissivity influences heat transfer via active walls and increases (decreases) the lower (upper) passive wall temperature, while no effect was noted on the dynamics.
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    Parametric Study of the Effective parameters on the Performance of Solar Chimney Power Plant
    (جامعة الوادي - university of el oued, 2021-06-25) Nouar, Hadda; Azizi, bdelghani; Chiba, Younes; Tahr, ,Toufik
    The solar chimney power plant (SCPP) is an effective option for electrical energy production from solar energy. In this paper, a numerical model to predict the SCPP performance is developed. The effects of collector angle and solar radiation are investigated on the parameters of air as the velocity and temperature. The study shows that when the collector angle is 20°, the velocity maximum is 1.8 m/s at the chimney base and the maximum temperature is 332.1k. in addition, increased solar radiation produces an increase in temperature (from 400 w/m² to 900 w/m²) and air velocity (from 22.25 m/s to 2.75 m/s) in the solar energy tower
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    Numerical study of a hybrid photovoltaic/thermal PVT solar collector using three different fluids
    (جامعة الوادي - university of el oued, 2021-06-29) Ghellab, A; Boukelia, T; .Djimli, TE.Djimli; . Kaabi, S; . Kaabi, . Kaabi,A A
    Hybrid photovoltaic and thermal (PV/T) systems have been widely used for the combination of PV modules and solar thermal collectors to generate both electrical energy and heat at the same time. In the present work, a numerical model has been developed to simulate the performances of a hybrid photovoltaic/thermal (PV/T) solar collector. Furthermore, a comparative study has been performed between the hybrid PV/T working with three conventional working fluids; air, water, and specified nanofluid (AL2O3+ water). The obtained results show that the use of the Alumina nanofluid is the best choice to increase the heat removal, and to improve the performances of the collector with the values of 73.28%, 10.37% and 99.21% for the thermal, electrical and global efficiency respectively. On the other hand, the PVT collector working with air as the primary fluid is the worst in terms of electrical, thermal, and global performances with the lowest values of 9.506 %, 41.55%, and 65.315% respectively.
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    Influence of the geographical parameters on the performance of hybrid solar gas turbine
    (جامعة الوادي - university of el oued, 2021-06-15) Behar, Omar; Belgasim, Basim; Sbarbaro, Daniel; Moran, Luis
    This study aims to investigate the influence of the geographical and climate parameters on the performance of the hybrid solar gas turbine with a pressurized air receiver. A number of sites located in South America (Chile, Bolivia, and Peru) and North Africa (Algeria and Libya) are considered. The geometric design parameters of the solar receiver and the tower are calculated using an in-house code. The layout and the optical performance of the heliostat field are carried out using SolarPILOT software. The simulation of the complete hybrid solar gas turbine is carried out using TRNSYS software. A 50 MWe hybrid solar gas turbine is chosen in this study. Results show that a hybrid solar gas turbine installed in North Africa performs better than that installed in South America. This is mainly due to the optical performance of the heliostat field, which are better in North Africa are than in South America. The highest annual optical efficiency of a solar field is observed at Bechar (Algeria) 56.8% while the lowest annual efficiency is observed at Antofagasta (Chile) 48.1%.The solar-to-electric efficiency at Atacama Desert is lower than in the Sahara Desert. Indeed, in Atacama region the solar-to-electric efficiency varies from 17% at Antofagasta to about 18% in Arequipa while it is above 19% at Sabha and Bechar
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    Experimental study of the effect of meteorological parameters on the performance of the solar chimney power plant
    (جامعة الوادي - university of el oued, 2021-06-16) Azizi, Abdelghani; Benmenine, Djamel; Nouar, Hadda; Kaddour, Abdelmadjid
    The solar chimney power plant (SCPP) is an economical technology for the production of solar electricity. The increase in the production efficiency of this type of installation is depended of the several theoretical and experimental studies. This paper studied the effect of some key parameters such as (ambient temperature, solar radiation), on the performance of the solar chimney power plant. Using the dimensions of our SCPP prototype and also compared by the Manzanares prototype with Ouargla weather conditions. Where the maximum solar radiation and ambient temperatures are 957 W/m2 and 30 ° C at 15h00. Respectively. The measured average air speed is 1.04 m/s, and the electric power value of the prototype is 2.04W. The results show that the solar radiation and the ambient temperature have a direct effect in the SCPP efficiency, and also confirm that the technology of solar chimneys is the best solution to install in the hot and arid areas like Ouargla city.
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    Effect of Rain on the Aerodynamic Performance of a Horizontal Axis Wind Turbine – A Computational Study
    (جامعة الوادي - university of el oued, 2021-06-26) Douvi, iEleni; Douvi, Dimitra; Pylarinos, Dimitrios; Margaris, Dionissios
    This paper analyzes numerically the impact of rainfall on the aerodynamic performance of a three-bladed Horizontal Axis Wind Turbine, with blades constructed by NACA 4418 airfoil. The simulations were conducted by the help of the commercial Computational Fluid Dynamics code, ANSYS Fluent 19.2. Firstly, the optimum geometry of the blade was designed with an application based on Blade Element Momentum theory. The Moving Reference Frame Model was applicated to simulate the rotation of the blades and the k-ω shear-stress transport turbulence model was added as well. The simulation of rain was accomplished by the Discrete Phase Model and the Taylor Analogy Breakup model was enabled to simulate droplets breakup. Three different rainfall conditions were studied, corresponding to Liquid Water Contents of 10g/m³, 30g/m³ and 60g/m³. The influence of droplet diameter on the aerodynamic performance of the blade was also examined. The results showed that the aerodynamic performance of the wind turbine is degraded in rain conditions, and the degradation is greater for higher values of Liquid Water Content and for larger diameter of water droplets.
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    Dynamic modelling of an earth-to-air heat exchanger for air cooling on the building in hot temperate climate of Beni Mellal Morocco
    (جامعة الوادي - university of el oued, 2021-06-15) Arroub, IsmailIsmail; Bahlaoui, Ahmed; Belhouideg, Soufiane; Kaddour, Abdelmadjid
    In this article, we examined the passive cooling techniques built into a building in hot temperate climate. Our work aims to reduce the energy demand for cooling and progress the thermal comfort of building by decreasing overheating hours. The dynamic simulations of the energy performance in a building with an earth-air heat exchanger (EAHX) are performed in the summer period using TRNSYS software. The building is situated in Beni Mellal city (Morocco) where the climate is a hot temperate one. The results of the simulations show a significant potential for air cooling. Indeed, for the hottest day of July (retained for this study), when the outside temperature is 44.8 °C and the cooled temperature (inside) is 29 °C, the difference of 15.8 °C is obtained. Also, an evaluation of the relative humidity is provided. Finally, we recommend that the Moroccan thermal code encourage the use of passive cooling techniques; precisely in temperate climate.