Papers by Keyword: Solar Desalination

Abstract: In the present study, three different D-Mannitol based activated bio-char composite shape-stable phase change materials (PCM) were developed for medium temperature energy storage applications like solar desalination, solar thermal storage and waste heat recovery with varying bio-char compositions. The activated bio-char (A-BC) composite-based samples were prepared from sawdust by using the pyrolysis method. The phase composition, morphology, latent heat capacity and phase change temperature of the fabricated samples were assessed by XRD, SEM, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The fabricated bio-char composite materials exhibited good thermal properties and structural stability compared to pure PCM. The phase change material with a blend of minimum 15 wt.% activated bio-char and 85% D-Mannitol was observed to be leak resistant. FTIR and XRD results confirm that the chemical properties of the bio-char composite remain the same as the pure PCM, which confirms that there are no chemical interactions between the PCM and bio-char. PCM sample with 15% activated bio-char exhibited an enhanced thermal stability compared to the pure PCM.

Abstract: Population density and automation is the main reason for the demand of drinking water. Water purification without affecting an ecosystem is the important need for daily life. Desalination is the best and effective way to satisfy the demand of fresh water. It is the most effective application of the solar energy. There are many conventional and non-conventional techniques available to make drinking water from the saline water. Among these solar desalination proves to be both economical and eco-friendly system particularly for rural areas. Solar stills are simple device which is used to provide pure water from the saline water by the principle of evaporation and condensation. This article reviews on the several research done on the solar stills to enhance productivity. Different designs of solar still and energy storage materials have been used to increase the yield and also this study proved the fact that efficiency of the solar still is majorly influenced by design and operating parameters.

Abstract: This paper presents the results of the experimental investigation on a solar flat plate collector carried out at Coimbatore, India (11°N Latitude and 74°E Longitude). The collector tubes allowed the water to flow twice across the flat plate collector using a circulating pump during which the water gets heated by the solar radiation received by the absorber. The maximum temperature of water obtained on a typical day in the month of April was 64°C with a solar radiation of 932.2651 W/m². The available solar radiation strongly influences the temperature gain of the system while the wind velocity plays a considerable role in influencing the heat lost by the system. It is observed that the two-pass flow of water across the absorber plate results in a maximum temperature gain with an overall collector efficiency of 43.7 %. This solar water heating system using flat plate collector can be used for small-scale desalination applications.

Abstract: This paper presents the thermal performance of a multi-effect distillation (MED) solar desalination unit located in southern China. The system was designed and installed in April 2011, and has been in operation since that time till now. The seawater desalination system is driven by 60 m² all-glass vacuum tubes solar collector with an additional rainwater utilization system to produce fresh water on both sunny and rainy days. The preliminary experimental results show that the water production of the system for per unit of solar collector area could reach up to more than 12.5kg/m²·day under the fine weather conditions. Water production of the system was stable in long period and the annual production could reach to 387.5 m³ in southern China. The economic performance of the system is also discussed. The cost of water production is estimated approximately 4.15 $/m³ for the 15-year service life.

Abstract: Abstract: Based on the analysis of heat and mass transfer and an empirical correlation, a new desalination unit which utilizes solar or waste energy has been developed and tested. In this desalination, a considerable fraction of the latent and sensible heat was successfully recycled and utilized for enhancing falling evaporation-condensation and preheating seawater via remaining heat. The performance of the unit was tested through experiments using an electric heater as heat source. The results indicate that the unit has excellent transient-state performance for effective heat and mass transfer. As a result of the unit operating with a solar system under practical weather conditions, the yield was about five times greater than that of a conventional single solar basin still with the same thermal energy input. The main factors which influence the freshwater yield were researched and analyzed. The reasonable ranges of some parameters were presented.