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The largest amount of energy in buildings is consumed to provide heating, cooling, and ventilation. Therefore, a practical solution such as using renewable energy sources can be considered to reduce energy costs and pollutants. In addition, architecture principles must be varied to utilize passive solar energy and also to reduce energy losses. In this research, a numerical study is presented to investigate the thermal behavior of TW-FR (Trombe wall placed in a fenestrated room) in the semiarid region of Tunisia. Computational fluid dynamic (CFD) simulation of fluid flow and heat transfer shows good agreement with published data in literature. The thermal comfort level was calculated according to ASHRAE (55-2013). The results show that (i) the normal Trombe wall cannot assure a satisfactory comfort level even in summer conditions and a higher vertical temperature gradient can take a value of 15°C, and the Trombe wall is shown to be more efficient in heating mode in the studied semi-arid region compared to cooling; (ii) the operative temperature for the coldest winter is between 17.85 and 19.85°C. The air temperature gradient in the comfort ranges between the head and feet is 2.3°C; and (iii) the Trombe wall is an excellent solution for Sousse city weather; it is suggested that the passive system (TW-FR) will be examined for a whole year to have a precise evaluation of its efficiency.

The world’s population is increasing rapidly. This means that energy consumption and demand for energy are also increasing at the same rate. It is estimated that energy will need to be provided to 9 to 10 billion people by 2040. India is a leading consumer of energy in the world. In particular, it consumes a large amount of oil and natural gas to fulfil its energy demand. Due to uncertainty in the supply of oil and natural gas and their prices as well as environmental pollution, there is a need to shift towards other energy sources. Biomass is one of the first energy sources with specific properties and abundant availability. Today, 10% to 14% of the world’s energy supply is provided by biomass sources. Using agricultural waste (biomass) to make briquettes to generate power can be an alternative solution to the problems related to their disposal and pollution. The present work investigates the optimum ratio of dry sugarcane leaves to binders and optimum load and selects the best binder (cow dung, buffalo dung, and press mud) for making high-quality briquettes. The physical parameters and proximate analysis of the dry sugarcane leaf briquettes with the cow dung, buffalo dung, and press mud binders are investigated. The dry sugarcane leaf briquettes with the cow dung binder have the highest gross calorific value, net calorific value, split tensile strength, tumbling resistance, shatter resistance, and energy density ratio (16262.31 kJ/kg, 15362.1 kJ/kg, 7.164 kN/m2, 87.84%, 12.75%, and 0.9296, respectively). The estimated results show that cow dung is a better binder for making high-quality dry sugarcane leaf briquettes than the buffalo dung and press mud binders.

Fouling in crude preheat trains in petroleum refineries affect the heat recovery from product streams significantly. Clear understanding on the effects of various operating conditions on fouling is still lacking among the researchers and practitioners. In the present study, a three-dimensional CFD model of a heat exchanger tube has been developed to predict the rate of coke deposition and fouling resistance through species-transport framework, in which, petroleum, asphaltenes and non-asphaltenes are represented as lumped pseudo-components in the crude oil. Asphaltenes particles were introduced into the bulk of crude oil and considered to be the only reactant for coke formation. The coke deposition rate and fouling resistance are predicted by varying the flow velocity, wall shear stress and surface roughness. From the CFD simulations, it is observed that the fouling resistance reduces under wall shear stress and surface roughness conditions as compared to no-slip and smooth surfaces, respectively.

The enhanced thermal properties are the prominent objective behind the usage of nanofluids. Hence, it is necessary to study the base/nanofluid physical properties at various conditions. This article projects the experimental results of thermal conductivity and viscosity of two different nanofluids. The ratio was considered as 60:40 and 40:40 by volume in water and ethylene glycol, respectively. The preparation of nanofluids was started by scattering SiO2 nanoparticles in EG and “water” (W) blended in “60:40” (60EGW) and “40:60” (40EGW) ratio by volume. The regression analysis was conducted with available data, and correlations were formulated for thermal properties. The nanofluids were used in evaluating “viscosity” and “thermal conductivity” experimentally. From the results, the SiO2 particles have achieved an enhancement of 34% and 32% in thermal conductivity with the two base fluids. Similarly, an enhancement of 102% and 62% was reported in viscosity. Hence, it can be observed that SiO2 nanofluids in 40EGW nanofluid are better heat transfer fluids when compared with SiO2 in 60EGW nanofluid.

Various studies have been made to improve the efficiency of the solar still. These studies had devoted to the combination of solar collectors with solar still. This article proposes the use of all forms of solar thermal or photovoltaic energy. In addition, photovoltaic electric storage systems convert them to thermal energy that increases the temperature of a greenhouse solar still. We investigated the possibility of improving the productivity of a greenhouse still and prolong solar distillation overnight. The proposed system is the incorporation of thermal energy produced by a parabolic-cylindrical concentrator, a greenhouse still, and photovoltaic solar energy by panels. The production at 14 pm reaches 110 L/m2 thanks to the various thermal sources made up of the hybrid still. It has better productivity than other distillers. The distillation is extended in the evening thanks to a storage system using electric batteries. The production at 18 pm to 18 L/m2 is reduced at 24 pm to 5 L/m2 in the dark. The accumulated temperature decreases the negative influence of the physical parameters on the production which exceeds 100 L/m2 per day. In the evening, the production is reached 16 L/m2 at 22 pm, which is an advantage compared to other distillers.

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