Experimental Analysis of Integrated System of Membrane Distillation for pure water with solar domestic hot water

• Main Author: Asim, Muhammad
• Format: Others
• Language: English
• Published: KTH, Energiteknik 2013
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-141141

In GCC countries, especially in UAE desalination of sea water is considered to be one of the most effective and strategic alternative for satisfying the current and future demand of water for domestic purposes. The depletion of ground water aquifers, rapid industrial development and increase of urban population in UAE lead to tremendous increase in fresh water demand during past decade. Although, desalinated fresh water is supplied to the consumers by local municipalities, people in the region rely mostly on bottled water for drinking purpose obtained through post desalination re-processing. Thousands of suppliers in UAE deliver bottled water to homes or offices thus leading to environmental unsustainability in the whole conversion chain from desalinated water to bottling, packaging and delivery. In fact, UAE is one of the leading countries in per capita bottle water consumption. Therefore, a need has been observed to provide safe drinking water for households in a sustainable way.In order to produce drinking water at homes, a concept of integrating Membrane Distillation (MD) based water purification with Solar Domestic Hot Water (SDHW) systems has been proposed and its feasibility has been evaluated in this research study. Present application is for a single family house/villa in UAE region that requires 20 l/day of drinkable water and 250 l/day of hot water for domestic purpose. An experimental pilot system has been installed at CSEM-uae for evaluating different operational parameters of such integrated system and also to determine overall thermal performance of the system. The study provides detailed design of experimental unit, procurement, installation and commissioning of the SDHW-MD integrated system along with estimated annual profiles of pure water and overall energy consumption.Experiments performed for one month during summer and distillate fluxes of around 4.5 – 12 l/m2/hour has been obtained with optimum MD hot and cold side flow rates of 6 and 3 l/min respectively and at hot side temperatures ranging from 50 - 70oC with cold side average temperature of 35oC. With recovery of cold side heat of MD unit, 25% of daily demand of DHW could be reduced and hence the estimated annual combined energy demand of 8220 kWh could be sufficiently fulfilled with either 8.5 m2 aperture area of Flat plate solar thermal collectors or with 7.5 m2 of Evacuated tubular collectors.