Energy and exergy analyses of a parabolic trough collector operated with nanofluids for medium and high temperature applications

Thermal performance of parabolic trough collectors (PTCs) can be improved by suspending nanoparticles into the traditionally used heat transfer fluids. In this work, a one-dimensional mathematical model is proposed to investigate the effect of various nanoprticles suspended in the working fluid for medium and high temperature PTCs. The major finding of this work is that the nanofluid enhances the thermal efficiency of the PTC slightly. High operating temperatures are more suitable for using nanofluids and generate higher relative gains of energy delivered. It is also found that the exergetic efficiency improvement is more important than energetic efficiency. The peak exergy efficiency is achieved by the CuO based nanofluid and is about 9.05%. The maximum daily relative gain of thermal energy delivered is found to be 1.46% by using 5% of Al2O3 in the base fluid. Optimal control of the operating conditions can lead to maximum energetic and exergetic performances of the PTC

Corrigendum to "Modeling of a Thermal Adsorber Powered by Solar Energy for Refrigeration Applications" [Energy 75 (2014) 589-596] DOI: 10.1016/j.Energy.2014.08.022

International audienceThe authors of the above mentioned article have noted some typing errors in Table 2. Under the heading of ``Adsorption model'' the subheading of m3 kg-1 should be corrected to W0, and the unit is [m3 kg-1]. Also, the next subheading of N must be changed to n. Under the heading of ``Combined heat and mass transfer'' the subheading of E should be corrected to \epsilon and the subheading of T to τ

Solar Absorption Air-Conditioning Systems: An Energy and Economy Approach

International audienceThis paper suggests the analysis and the simulation of a complete solar absorption cooling installation. The building reference is a three floors office located in Fez (Morocco). Energy and economy analysis were investigated based on different performance indicators. It was put in evidence that the adoption of solar air conditioning systems depends strongly on the thermal energy market status

Analysis of the Electrical Energy Consumption and Energy Audit of Interior Lighting for an Industrial Site in Morocco

International audienceThis paper is an energy audit performed for an industrial site based in FEZ (Morocco), specialized in producing and commercializing cattle feed It evaluates the economic gains related to an optimized management of the electrical energy use and focuses on the improvement of energy efficiency for the interior lighting. \textcopyright 2015 IEEE

Yearly Performance of Low-Enthalpy Parabolic Trough Collectors in MENA Region According to Different Sun-Tracking Strategies

International audienceSolar parabolic trough collector (PTC) is a very popular system in solar concentration technology, which is widely used for electric production and heat generation in industrial processes. In this paper, a validated mathematical model has been proposed to evaluate the performance of low-enthalpy PTC in five sites of the MENA region: Ouarzazate (Morocco), Gafsa (Tunisia), Jeddah (Saudi Arabia), Amman (Jordan) and Aswane (Egypt). A MATLAB program was developed to simulate the hourly thermal performance of the PTC under fluctuating climatic conditions. A particular attention has been given to the effect of the sun-tracking technique on the collector's performance. The model validation was carried out in two phases: first, by comparison with the results generated by the System Advisor Model software, and second by comparison with experimental data. In both cases, a very close agreement is obtained. The results have shown clearly that the tracking technique, climate and season of the year have a significant impact on the PTC performance. The best site for implementing such technologies was found to be Ouarzazate (Morocco) with a useful annual energy generation potential varying from 104.85 to 154.57 MWh. On December 24, the PTC operating in Ouarzazate using 0.2 kg/s mass flow rate, the outlet water temperature can achieve a maximum temperature of 70 °C using the full-tracking and N-S tracking techniques, while the outlet temperature does not exceed 46.5 °C using the E-W tracking. This temperature can reach 82 °C on July 07, by using the full-tracking and E-W tracking modes. From a general aspect, it was also concluded that the optimal cost-effective tracking strategy for the annual heat generation is the E-W polar tracking one independently of the geographical location. \textcopyright 2017 Elsevier Lt

Simulation of a Thermoelectric Heating System for Small-Size Office Buildings in Cold Climates

International audienc

Energy and Parametric Analysis of Solar Absorption Cooling Systems in Various Moroccan Climates

International audienceThe aim of this work is to investigate the energetic performance of a solar cooling system using absorption technology under Moroccan climate. The solar fraction and the coefficient of performance of the solar cooling system were evaluated for various climatic conditions. It is found that the system operating in Errachidia shows the best average annual solar fraction (of 30%) and COP (of 0.33) owing to the high solar capabilities of this region. Solar fraction values in other regions varied between 19% and 23%. Moreover, the coefficient of performance values shows in the same regions a significant variation from 0.12 to 0.33 all over the year. A detailed parametric study was as well carried out to evidence the effect of the operating and design parameters on the solar air conditioner performance

Grid-Connected PV Systems Installed on Institutional Buildings: Technology Comparison, Energy Analysis and Economic Performance

International audienceIn this paper, a performance analysis and economical/environmental assessment of two grid-connected PV systems in Meknes (Morocco) were carried out and their real energy production was reported. The PV system installed in an institutional building, consisted of polycrystalline silicon (Poly-Si) and monocrystalline silicon (Mono-Si) solar cell technologies. The monthly average and annual performance parameters of the PV systems assessed include the total energy generated, final yield, capacity factor and overall system efficiency. It is found that, for the same rated capacity, Poly-Si modules have higher monthly total average final yield than Mono-Si modules. Generally, the installed PV systems in Meknes possess higher performance indicators compared to other regions in the world like Greece, Ireland, India, South-Africa and UAE. This study has also evaluated the levelized cost of electricity (LCOE), Payback time (PB) and annual avoided CO2 emissions for the two systems under investigation. The LCOE found to be in the range 0.073\textendash0.082 \/kW h and PB found to be in the range 11.10\textendash12.69 years for this analysis. Furthermore, it was shown that the installed PV systems have the potential of reducing approximately 5.01 tons of CO2 emission per year