Ahmed Mezrhab

Performance of parabolic through solar power plant under weather conditions of the Oujda city in Morocco

A numerical simulation of Concentrating Solar Power (CSP) plant based on an Organic Rankine Cycle (ORC) power generation unit integrated with parabolic trough collectors is carried out. For the study we refer to the Solar Electric Generating System VI (SEGS VI), installed in the Mojave desert-California (USA), whose solar field which is constituted by LS2 parabolic trough collectors and we consider the same plant implementation in the region of Oujda city (Morocco). To predict the energy performance, the simulations are carried out using TRNSYS 16 simulation program known for its modularity and flexibility and the external library known as the Solar Thermal Electric Components (STEC) library. The meteorological parameters including Direct Normal Irradiation (DNI), ambient temperature and other weather conditions are taken from meteorological year database provided by a high precision MHP station located in Mohamed Premier University. The obtained results show that the region of East offers great potential in general for implementing this type of plant. In fact, the value of 30 MWe is reached during the strongest sunshine day and the operating time can go from 7 AM until 19 PM for a summer day.

Combined Natural Convection and Thermal Radiation Heat Transfer in a Triangular Enclosure with an Inner Rectangular Body

In this paper, a numerical simulation was conducted to investigate the steady laminar natural convective heat transfer and surface radiation from a heated rectangular body in a triangular enclosure. The coupled equations of Navier-stockes and energy are both solved using the finite volume method. The velocity-pressure coupling is insured by the SIMPLER algorithm. The fluid used in this study is a dry air of Prandtl number Pr = 0.71.In such way that, the radiative exchanges are made only through solid walls and which are assumed to be gray and diffuse. The physical parameters characterizing the problem and influencing heat transfer are Rayleigh number Ra, aspect ratio A, height h and width w of the body. The results are presented in terms of isotherms, streamlines and average Nusselt number.

The uncertainty of the HelioClim-3 DNI data under Moroccan climate

The purpose of this study is to evaluate the uncertainty of the DNI satellite-derived data from HelioClim-3 against those measured at ground level by calculating the classical statistical performance indicators for different time resolutions (hourly, daily and monthly). Correlations between the errors and the Aerosol optical depth (AOD) data measured by an AERONET sun photometer station at the University of Oujda were performed. Results show that the DNI data derived from Helioclim-3 can be considered as acceptable for satellite data with an RMSE of 19.7 % and a bias of 7.9 % for the hourly data. HelioClim-3 systematically over-estimates the daily DNI sums for the investigated site. The correlation to AOD at 550 nm can only be one of the reasons for the deviation. Corrections or site adaptation could help to increase the accuracy of the data base for that pixel.The purpose of this study is to evaluate the uncertainty of the DNI satellite-derived data from HelioClim-3 against those measured at ground level by calculating the classical statistical performance indicators for different time resolutions (hourly, daily and monthly). Correlations between the errors and the Aerosol optical depth (AOD) data measured by an AERONET sun photometer station at the University of Oujda were performed. Results show that the DNI data derived from Helioclim-3 can be considered as acceptable for satellite data with an RMSE of 19.7 % and a bias of 7.9 % for the hourly data. HelioClim-3 systematically over-estimates the daily DNI sums for the investigated site. The correlation to AOD at 550 nm can only be one of the reasons for the deviation. Corrections or site adaptation could help to increase the accuracy of the data base for that pixel.