Soil inertia and shallow basement envelope impact on cellar internal temperature

This work deals with a three dimensional numerical study of heat transfer by conduction between the soil and the shallow basement in the city of Marrakech (Morocco). The heat transfer equation is solved by the finite difference method using the implicit alternative direction (ADI). The internal temperature of the cellar is computed by using energy balance equation in the cellar. The objective of this work is to evaluate the effects of the nature of the soil, the nature of the walls, the thickness of the walls of the cellar and the distance L far from the cellar on the internal temperature and the heat exchanged between the soil and the shallow basemen

Development of Alfa Fiber-Based Mortar with Improved Thermo-Mechanical Properties

This work deals with the development of a new composite based on mortar reinforced with optimally sized alfa fiber (AF). Experimental investigations of physical and thermo-mechanical properties of the new AF mortar composite are performed for AF weight fraction varying from 0% to 5%. This simple material preparation process is described and scanning electron microscopy (SEM) is undertaken to analyze the morphology of this composite. It shows a random dispersion of the AF into the mortar matrix. Physical properties such as open porosity, water absorption, and bulk density fluctuations with AF mass content are measured. Measured thermal conductivity is compared to the values generated by different prediction models. Good agreement, within 9.6%, is obtained with data predicted by Woodside–Messmer’s method. It is demonstrated that this simple blending of AF into mortar improves significantly the thermo-mechanical behavior of the new composite. An addition of 5% of AF weight content makes composite material lighter by about 15%, enhances its insulating thermal capabilities by about 57% and increases its heat diffusion damping rate by about 49%. Moreover, the composite mechanical (flexural and compressive) strength increases by up to 10% for an AF weight content of 1%

Comparison of shallow basement thermal performance for different regions of Morocco using a three-dimensional heat transfer analysis

A three-dimensional numerical model was built to estimate the heat transfer between the soil and a shallow basement in four different climates (cold, temperate, semi-arid and arid climates) for, respectively, conditioned and unconditioned cases. The governing heat transfer equation in soil and basement was solved by the finite difference method using the alternating-direction implicit scheme (ADI). The air temperature for the case of conditioned shallow basement was maintained constant while it was computed for the case of unconditioned cellar using energy balance equation. The effects of the basement geometry, soil types and climatic conditions on the thermal behavior of the conditioned and unconditioned shallow basement were carried out. The heat losses and isotherms analysis showed that the heat flux is more significant through the walls than the basement floor and occurred mainly in the walls-floor edges. Furthermore, lowering the thermal diffusivity of the soil leads to a decrease in the shallow basement heating load. Our results show that the shallow basement as expected is more beneficial in hot climates than in cold ones. It was also brought to light that the basement thermal load is dependent on the soil type in temperate climates

Experimental and Numerical Investigations on Conductive Drying of Phosphate Washing Waste Clay

Morocco is the leading producer of phosphate and its derivatives in the world with a total production of 35 Mt. However, the extraction and the valorization of this mine generate huge quantities of phosphate washing waste clay (PHWWC) that constitute a main environmental and economic concern. To facilitate this waste clay storage and handling, it is necessary to decrease its moisture content that represents 80% of PHWWC. The present paper is devoted to studying the conductive drying of PHWWC. Drying experiments were conducted in a laboratory pilot. Afterwards, the experiment results were implemented in a one-dimensional numerical model of heat and mass transfer in a porous media to identify the drying parameters and performances. It was found that most of the water contained in PHWWC is free water that is removed with a constant drying rate. The volume reduction with a marked cracks phenomenon attained 65% without any significant effect of drying temperature and sample thickness. The effective moisture diffusivity of the PHWWC for a conductive drying process is ranged between 10−9 and 1.1 × 10−8 m2·s−1. The thermal efficiency of the drying system is up to 86%. The results could be used for the purpose of design and scale-up of the industrial dryer based on laboratory-scale experiments