Abstract
Tremendous increase in fresh water demand in United Arab Emirates (UAE) over the past few decades, because of rapid industrial growth and increase of urban population, has led to increased stress on underground water aquifers. In order to cater the current and future water requirement for domestic use in UAE, desalination of seawater is considered to be one of the most effective and strategic technique. Therefore, we studied simultaneous production of quality drinking water and solar domestic hot water for a single family villa in UAE resided by 4 to 5 persons. A pilot plant setup was designed, commissioned and installed on site using Air Gap Membrane Distillation desalination process to fulfill the demand of 15-25 L/day of drinking water and 250 L/day of hot water for domestic use. Experimental analyses were performed during a summer season on flat plate solar collectors having different aperture areas; experiments were performed for aperture area of 11.85 m2 for feasibility purpose. The average hot side temperature of membrane distillation circuit ranges from 50°C - 70°C whereas the average cold side temperature is 35°C. The experimental results show that for 10 hours operation of pilot plant, 16 Ls of total volume of distillate has been collected. The specific flow rate of water has been kept low to get higher temperatures and as a result. The total solar yield was 31.3 kWh out of which the membrane distillation energy usage was 41.3% and the domestic hot water energy usage came out to be 18%. The energy consumption per L of water was found to be 0.804 kWh/L. Some of the energy was lost due to long length of piping, which can be avoided by more effective insulation
