Theoretical and Experimental Quantification of Solar Radiation through a Tracking System

This work deals with the estimation of solar radiation through a solar tracker aimed at evaluating the effect of solar tracking on the solar deposit in Burkina Faso. Using a two-axis solar tracking system, we experimentally measured solar radiation at our Joseph KI-ZERBO University site and compared it with that obtained by a numerical simulation run using Fortran programming software based on a mathematical model by Brichambaut. The results obtained from the mathematical and experimental studies show that, with a solar tracker, on a clear-sky day, solar irradiation is between 800 W·m−2 and 1000 W·m−2 between about 8 a.m. and 4 p.m., i.e. a duration of 8 hours of insolation. Analysis of the numerical and experimental results shows very good quantitative and qualitative agreement, with an average relative error of 18%.

Hygrothermal Study of a House Made of Local Biosourced Materials Based on Clay: Experimental Study

The purpose of this study is to experimentally analyze the thermal behavior of the walls of a prototype experimental house. A Datalogger and thermocouples were used on the experimental house to determine the temperatures of the exterior and interior walls. Also, “MSR” type HygroPuce was used to determine the exterior and interior temperatures and relative humidity of the habitat. The results show that a wall made of bio-based materials with a mixture of “earth + Hibiscus cannabinus L. fibers” allows reducing the fluctuations of the interior temperatures. We observe the peaks of temperatures on the external walls at 11:00 am and for the interior walls, the peaks are observed at 5:00 pm. The maximum thermal phase shift between the peaks of the external and internal temperatures is about 7.5 hours, and the maximum damping factor is 0.9. Also, we note that the thermal performance of the material used in the design of the envelope of the house is determined by the improvement of the response of the envelope in front of the external thermal solicitations.

Development of Sensible Heat Storage Materials Using Sand, Clay and Coal Bottom Ash

In this paper, the mechanical and thermal properties of a sand-clay ceramic with additives coal bottom ash (CBA) waste from incinerator coal power plant are investigated to develop an alternative material for thermal energy storage (TES). Ceramic balls are developed at 1000°C and 1060°C using sintering or firing method. The obtained ceramics were compressed with a compression machine and thermally analyse using Decagon devise KD2 Pro thermal analyser. A muffle furnace was also used for thermal cycling at 610°C. It was found that the CBA increased the porosity, which resulted in the increase of the axial tensile strength reaching 3.5 MPa for sand-clay and ash ceramic. The ceramic balls with the required tensile strength for TES were selected. Their volumetric heat capacity, and thermal conductivity range respectively from 2.4075 MJ·m-3·°C-1 to 3.426 MJ·m-3·°C-1 and their thermal conductivity from 0.331 Wm-1·K-1, to 1.014 Wm-1·K-1 depending on sand origin, size and firing temperature. The selected formulas have good thermal stability because the most fragile specimens after 60 thermal cycles did not present any cracks. These properties allow envisioning the use of the ceramic balls developed as filler material for thermocline thermal energy storage (structured beds) in Concentrating Solar Power plants. And for other applications like solar cooker and solar dryer.

Characterization and Potential Recovery of Household Solid Waste in the City of Ouagadougou (Burkina Faso)

This study on physical and physicochemical characteristics of household solid waste (HSW) in the city of Ouagadougou by using MODECOM, “Method of Characterization of Household waste” was done fifteen (15) years after the first study. Special attention has been paid to waste sampled and also to estimate energy content, namely the higher heating value (HHV) and the lower heating value (LHV). As a general tendency, the results showed a sensitive evolution in the physical parameters of waste (composition by size and composition by category) and also in the physicochemical parameters (moisture content and energy content). The results of HSW composition study showed that regardless the seasons, fermentable fraction is dominant (39% in the rainy season and 20% in the dry season) followed by plastics (18% in the rainy season and 20% in the dry season). The moisture content is measured to be 56.69% and 37.69% respectively in the rainy season and dry season. The results analysis of the potential of recovery showed that the organic recovery is more important (60% in the rainy season and 55% in the dry season) than the matter recovery (43% in the rainy season and 46% in the dry season). These results highlight the need for organic recovery and matter recovery of HSW in the city of Ouagadougou. The results from the analysis of the energy content showed that the HHV is estimated to be 17.94 MJ/kg in the rainy season and 17.96 MJ/kg in the dry season. The LHV is calculated to be 6.38 MJ/kg in the rainy season and 10.27 MJ/kg in the dry season. These results suggest that incineration as treatment of HSW in the city of Ouagadougou is not economically an appropriate option.

Assessment of CH4 and C 2 surface emissions from Polesgo’s landfill(Ouagadougou, Burkina Faso) based on static chamber method

Methane (CH4) and carbon dioxide (C02) surface emissions from Polesgo's landfill (Ouagadougou, Burkina Faso) were measured using the static chamber technique in 2017 and 2018. The Polesgo's landfill was composed of four zones: Phase I, II, Phase III, and SP. The surface of Phase I was fully covered and its conditions are better for surface emission measurements. As results concerning the Phase I zone, the geospatial means flux rates of CH4 (657 mg m-2 h l in 2017 and 1210 mg m 2 h_, in 2018, respectively) are measured higher than the tolerable value reported in literature. The emitted CH4 or C 02 have permitted to locate higher surface emissions which are related to the cover state. The calculated gas collection efficiency (27.4% in 2017 and 23.0% in 2018) is low compared to those reported for landfills integrating landfill gas (LFG) extraction system. The carbon footprint calculations (24,966 tC02-eq 2017 and 40,025 tC02-eq in 2018, respectively) shown that Polesgo's landfill is a significant source of greenhouse gases (GHG) and its important potential for organic recovery can contribute to reduce the carbon footprint.

Effect of Adsorbent/Adsorbate Couple on the Performance of Adsorption Solar Refrigerator

This work presents a contribution to the study of the process of cold production by adsorption from solar energy. In this paper, we discuss a comparative study of the operation of a solar adsorption refrigerator using the silica gel-water couple and the zeolite-water couple through dynamic modeling and simulation. The mathematical model representing the evolution of heat and mass transfer at each component of the adsorption solar refrigerator has been developed. It appears from this study that the evolution of the temperature of the two adsorbents (zeolite and silica gel) is quasi-similar throughout the operating cycle. However, the maximum mass of water vapor adsorbed by the silicagel (0.24 kg/kg) is higher than that adsorbed by the zeolite (0.201 kg/kg). In the same way, the mass of water vapor cycled, obtained with the silicagel-water couple which is 0.14 kg/kg, is higher than that obtained with the zeolite-water couple which is 0.081 kg/kg. Therefore, the amount of cold produced 9.178 MJ and the solar coefficient of performance 0.378 obtained with the solar refrigerator using the silica gel-water couple, are better.