EFFECT OF SHADING ON THE PERFORMANCE AND PRODUCTIVITY OF DOUBLE SLOPE SOLAR STILL UNDER CLIMATIC CONDITIONS OF EGYPT | ||
| Misr Journal of Agricultural Engineering | ||
| Article 20, Volume 33, Issue 2, April 2016, Pages 679-696 PDF (484.26 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/mjae.2016.98013 | ||
| Author | ||
| I. H. El-Sheikh | ||
| Associate Prof. of Agric. Eng. Dep., Fac. of Agric., Suez Canal Univ., 41522 Ismailia, Egypt. | ||
| Abstract | ||
| The present work aims to study the possibility of enhancing and increasing the productivity of fresh water from the double slope solar still by improving the performance of its condenser. Single basin asymmetrical double sloped solar still was employed during this study. The study was carried out on the roof of Agricultural Engineering Department, Suez Canal University, Ismailia Governorate (Latitude and Longitude angles, respectively, are 30.62ºN and 32.27ºE, and mean altitude above the sea level is 20 m). The solar still consists mainly of a rectangular iron basin (1.80×0.80 m) and 0.10 m deep. The bottom frame was constructed of wood and insulated by 2 cm thick of rock wool. The outer walls of the bottom frame were insulated with 7 cm thick of foam. The condensing zone consists of two inclined surfaces. The first inclined surface (which has the area of 1.46 × 1.05 m2) covered with glass sheet (3 mm thick) to transmit the maximum possible of solar radiation flux incident on it. It was orientated to face the south direction with an inclination angle of 20○. The second inclined surface (which has the area of 1.05×0.83 m2) covered with the same material and the same thickness. It was orientated to face the north direction with an inclination angle of 30○. Two configurations of experiments were performed. Firstly, studying the thermal performance of solar still under local climatic conditions. Secondly, exam lowering the northern glass cover temperature by shading it. This procedure lowered the high temperature of the northern cover, thus the temperature difference between water and northern cover was increased. The solar radiation intensity, wind speed, ambient temperature, amount of fresh water productivity and temperature of other components of the solar still were continuously measured. The experimental results revealed that, the daily average productivity of fresh water during the first and second configurations was found to be 2.9 and 3.3 l/d, respectively, with an increasing of 13.79%. The maximum values of heat transfer coefficient inside the solar still were 2.2, 7.5 and 33.3 W/m2 K for convective, radiative, and evaporative coefficients, respectively. Because of the evaporative heat transfer coefficient strongly depends on the operating water temperature it was had the highest value. It was also found that, the maximum amount of heat losses that occur in the solar still was the radiation and convection heat transfer from glass to ambient air. | ||
| References | ||
|
Al-Hayek I. and Badran O. (2004) "The effect of using different designs of solar stills on water distillation" Desalination, 169, 121-127
Bahadori M. M. and Edlin F. E. (1973) "Improvement of solar stills by the surface transparency of the glass" Solar energy, 14, 339–352
Boukar, M. and Harim, A. (2003) "Development and testing of vertical solar still" Desalination, 158, 158-179
Cooper, PI. (1973) "The maximum efficiency of a single effect of solar stills" Solar Energy, 15, 3, 205-217
Duffie, J. A. and Beckman, W. A. (2006) "Solar Engineering of Thermal Processes" New York, N.Y., John Wiley and Sons, USA
Dunkle, R. V. (1961) "Solar water distillation, the roof type solar still and a multi effect diffusion still, International developments in heat transfer, ASME Proceedings of International Heat Transfer" University of Colorado. 5, 895-902.
El-Bahi, A. and Inan, D. (1999) "A solar still with minimum inclination, coupled to outside condenser" Desalination, 123, 79-83
Fath, E. S. and Hosny, H. M. (2002) "Thermal performance of a single-sloped basin still with an inherent built-in additional condenser" Desalination, 142, 19-27
Fath, H. E. S. (1998) "Solar desalination: a promising alternative for water provision with free energy, simple technology and a clean environment" Desalination, 116, 45-56
Fernandez, J. and Chargoy, N (1990) "Multi-stage, indirectly heated solar still" Solar Energy, 44 (4): 215-223
Gracia-Rodriguez, L. (2004) "Desalination by wind power" Wind Engineering, 28, 453-466
Kabeel, A. E.; Omara, Z. M.; and Essa, F. A. (2014) "Enhancement of modified solar still integrated with external condenser using nano-fluids: An experimental approach" Energy Conversion and Management, 78, 493-498Malik, M. A.; Tiwar, G. N.; Kumar, A.; and Sodha, M. S. (1982) "Solar Distillation" Pergamon press Ltd, Oxford, UK.
McAdams, W. H. (1954) "Heat Transmission" 3rd ed. McGraw-Hill Book Company, N.Y, USA
Rajaseenivasan, T.; Elango, T.and Mrugavel, K. K. (2013) Comparative study of double basin and single basin solar stills. Desalination, 309, 27-31
Taamneh, Y. and Taamneh, M. M. (2012) "Performance of pyramid-shaped solar still: Experimental study" Desalination, 291, 65–68
Tiwari, G. N. (2002) "Solar Energy, Fundamentals, Designs, Modeling and Application" CRC press, New Delhi, Narosa Publishers, pp. 279-309
Tiwari, G. N. and Tiwari, A. K. (2008) "Solar distillation practice for water desalination systems" New Delhi, Anamaya Publishers.
Tiwari, G. N.; Dimri, V.; Singh, U.; Chel, A. and Sarkar, B. (2007) "Comparative thermal performance evaluation of an active solar distillation system" International Journal of Energy Research, 31, 1465-1482
Velmurugan, V. and Srithar, K. (2007) "Solar stills integrated with a mini solar pond-analytical simulation and experimental validation" Desalination, 216, 232-241
Zeroual, M.; Bouguettaia, H; Bechki D.; Boughali, S; Bouchekima B. and Mahcene, H. (2011) "Experimental investigation on a double slope solar still with partially cooled condenser in the region of Ouargla (Algeria)" Energy Proc., 6, 736-742 | ||
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