A Theoretical and Experimental Study for A humidification-Dehumidification (HDD) Solar Desalination Unit
A humidification-dehumidification (HD) solar desalination unit was designed. It seems to be suitable to provide drinking water for population or remote arid areas. Solar water and solar air collectors were designed to provide the hot water and air to the desalination chamber. The desalination chamber was divided into humidifier and dehumidifier towers. The circulation of air in the two towers was maintained by the forced convection. Theoretical and experimental works were done at different environmental conditions. A mathematical model was formulated, in which the thermodynamic relations were used to study the flow, heat and mass transfer inside the humidifier and dehumidifier. Such a technique was performed in order to increase the unit performance. Heat and mass balance was done and a set of governing equations was solved using the finite difference technique. The solar intensity was measured along the working day during the summer and winter months and a comparison between the theoretical and experimental results were performed. The average accumulative productivity of the system in November, December and January was ranged between 2 to 3.5 kg / m day while the average summer productivity was found between 6 to 8 kg/m day in June and 7.26 to 11 22
Water Desalination using Solar Energy: Humidification and Dehumidification Principle
The objective of this paper is to demonstrate an experimental investigation of a water desalination system using solar energy that applies the humidification and dehumidification principle. A prototype/test rig was designed, fabricated and assembled in order to study the effect of water flow rate and the humidifier inlet water temperature against desalinated water productivity. The system consists of a spray type with no packing bed humidifier, a copper coiled Dehumidifier, a flat plate solar water heater, an air blower, a water pump, a water flow meter, a water tank, three thermocouples and four gate water valves. The system is based on an open waterclosed air cycle. A new approach is used such that the humidifier, dehumidifier and the connecting duct between them are made of Poly Vinyl Chloride (PVC) pipes; which makes the system lighter in weight, doesn’t need insulation unlike metal sheets and anti-rust. The effect of operating parameters on the system characteristics has been controlled, measured and investigated. It was found that the hot inlet water temperature to the humidifier has a significant impact on the water productivity; they are relatively proportional, thus, the more the hot inlet water temperature increases, the more the water productivity increases. It was also found that Saline water flow rate has an impact on the water productivity but inversely proportional.
A new stochastic factor model: General explicit solutions
We present a new stochastic factor model. In doing so, we provide general, explicit solutions to the portfolio optimization problem.