In direct contact membrane distillation (DCMD), heat and mass transfers occur through the porous membrane. Any model developed for the DCMD process should therefore be able to describe the mass transport mechanism through the membrane, the temperature and concentration effects on the surface of the membrane, the permeate flux, and the selectivity of the membrane. In the present study, we developed a predictive mathematical model based on a counter flow heat exchanger analogy for the DCMD process. Two methods were used to analyze the water permeate flux across one hydrophobic membrane layer, namely the log mean temperature difference (LMTD) and the effectiveness-NTU methods. The set of equations was derived in a manner analogous to that employed for heat exchanger systems. The obtained results showed that the permeate flux increases by a factor of approximately 220% when increasing the log mean temperature difference by a factor of 80% or increasing the number of transfer units by a factor of 3%. A good level of agreement between this theoretical model and the experimental data at various feed temperatures confirmed that the model accurately predicts the permeate flux values for the DCMD process.

Solar energy is a renewable and sustainable source of energy, and it has been used in addition of specified technologies, such as solar cooling. The demand for cooling continues to increase in line with environmental changes and a greater desire for human comfort. This study primarily aimed to analyze the performance of an evaporative cooling system powered by solar energy and assess the economic and environmental impact of this system. In this system, hot, dry incoming air is used to evaporate water, thus transforming part of its sensitive heat into latent heat without any variation in enthalpy or total heat. The outputted air then has a lower temperature and a greater humidity, thus providing a more comfortable, healthier environment for its users. To achieve this study’s objectives, numerical code was developed and implemented in MATLAB. The obtained results reveal that the efficiency of the evaporative cooler exceeds 90%, with maximum efficiency being reached at a high wet-bulb depression, while minimum efficiency was observed when the dry air has a high relative humidity and a low dry-bulb temperature.

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