Mathematical Modeling for Performance Prediction of a Humidification – Dehumidification Solar Water Desalination System in Egypt

Abstract

SIMPLE water desalination system using humidification-……...dehumidification process (HDH) enhanced with solar energy was theoretically studied. In the presented system, a double jacket solar water storage tank was used to heat the saline water in a separate independent circuit. A natural circulation solar water cycle between the flat plate collector and the storage tank was introduced to prevent salt scales formation inside the internal boundary layers of the flat plate collector tubes and heating system network. The humid air in the atomization chamber was collected on the condenser surface that cooled by water using thermoelectric refrigeration technique. This refrigerator was powered by a DC electric source provided by a solar photovoltaic module to maximize the water yield. The simulation model was built using the local meteorological conditions of Cairo, Egypt (30° 2' N latitude, 31° 14' E longitude). Results showed that the daily production of condensed water depended on the flow rate and temperature of saline water in addition to air mass flow rate and its pressure. It is found that the maximum productivity of the system is achieved in summer season with a value of 64.3 L/day and it is found that each kWh/m 2 /day falling on the collector surface produced 7.9 L/day. Although the produced quantity of desalinated water is small, yet it can help inhabitants especially in rural and remote areas where potable water is unavailable to be kept survived. Moreover, this system could be replicated to produce more desalinated water for inhabitants demand. As Egypt enjoys long coastal area of about 2500 km in length as well as abundant solar energy most time of the year will encourage the Egyptian government to install several solar water desalination plants with several technologies. One of the most promising and simple technologies is the HDH Process.