THE INFLUENCE OF PORES SIZE AND TYPE OF AGGREGATE ON CAPILLARY HEAT AND MASS TRANSFER IN POROUS
One of the latest development of absorber plate in solar still application is the implementation of porous media.This study aims to analyze the effect of aggregate’s pore size and type towards the capillary-driven fl ow and evaporation process in porous media. In order to enhance the evaporation process five different types of porous media had been chosen, namely concrete consisted river sand with the particle size of 0.125 and 0.250 mm, ferrous sand concrete with particle size of 0.125 and 0.250 mm, and natural stone as the comparison material. Top side of the specimens was exposed in a heater with 18.2 W, 27.3 W and 36.4 W. The bottom side of specimen was exposed in seawater which flowed capillary and evaporated. The value of thermal conductivity and porosity in porous media greatly affect the temperature distribution caused by the heat transfer process. Specimens with smaller particle size has a higher thermal conductivity which resulting in a larger heat transfer rate. Concrete with ferrous sand as aggregate has a better heat transfer rate than river sand specimen. The largest heat transfer rate obtained in concrete with 0.125 mm ferrous sand with the value of 0.256 W, 0.402 W and 0.524 W in every power addition. The rate of mass transfer value equals to the rate of evaporation that occurs and strongly depends on the capillary force of each specimen. The evaporation rate data is proportional to the heat transfer rate of each specimen. However the natural stone specimen has a higher evaporation rate than expected due to better interconnectivities between its channels.
1. Siti N.S.; Omar El-Hadad; Syarifah b.A; Rahim; and Chew Few Ne. (2017)Solar still; unrevealed facts and reasons causing its low productivity.Journal of Engg. ResearchVol. 5 No. (1) pp. 181-19
2. Bilal, H.; Gahafoor, Abd.; and Munir, Anjum. (2016). Desalination of brackish water using dual acting solar still. Journal of Engg. ResearchVol. 4 No. (4) pp. 178-193
3. Bouchekima, B.; Gros, Bernard.; Ouahes, Ramdane.; and Diboun, Mostefa. (2001). Brackish water desalination with heat recovery.Desalination. vol.138. 47–155.
4. Bouchekima, B. (2002). A solar desalination plant for domestic water needs in arid areas of South Algeria. Desalination. vol. 153: 65–69.
5. Murugavel Kalidasa K.; Chockalingama Kn.K.S.K.; and Srithar K. (2008). An experimental study on single basin double slope simulation solar still with thin layer of water in the basin. Desalination 220: 687–693 .
6. Hansen R.S.; Narayanan, C.S.; and Murugavel, K.K. (2015). Performance analysis on inclined solar still with different new wick materials and wire mesh. Desalination 358: 1–8
7. Beyhaghi; Saman; Geoffroy; Sandrine, Prat.; Marc.; Pillai.; Krishna M. (2014).Wicking and evaporation of liquids in porous wicks: a simple analytical approach to optimization of wick design. AIChE Journal, vol. 60 (n°5): 1930-1940. ISSN 0001-1541
8. Tiwari, G.; and Yadav, Y. (1987). Comparative designs and long term performance of various designs of solar distiller. Energy conversion and management, 27(3):327-333.
9. Khalifa, A.-J.; Al-Jubouri, A.; and Abed, M. (1999). An experimental study on modifi ed simple solar stills. Energy conversion and management, 40(17):1835-1847
10. Chabane, F., Moumm, N.i, Benramache, S., Bensahal, D., and Belahssen, O.. (2013). Collector efficiency by single pass of solar air heaters with and without using fins. Engineering Journal. Volume 17 Issue 3.
11. Cengel, A. Yunus.; and Cimbala, John M. (2006). Fluid mechanics: Fundamentals and aplication. McGraw Hill. New York
12. Hanzˇicˇa, L. and Ilic´a, R. (2003). Relationship between liquid sorptivity and capillarity in concrete. Cement and Concrete Research 33: 1385–1388
13. Nield D.A.; and A. Bejan. (2013). Convection in Porous Media, in Convection Heat Transfer. John Wiley & Sons, Inc., Hoboken, NJ, USA
14. Anggara, Wahyu Tri. (2011).Studi Pemetaan Potensi Tambak Garam di Kecamatan Kabupaten Probolinggo Jawa Timur,Unpublished, Malang. Brawijaya University
15. Zhao T.S.; Liao Q. (1999). On capillary-driven fl ow and phase-change heat transfer in a porous structure heated by a fi nned surface: measurements and modeling. International Journal of Heat and Mass Transfer 43 (2000) 1141-1155
16. O.I. Popoola, J.A. Adegoke and O.O. Alabi, (2009). The Effects of Porosity and Angle of Inclination on the Defl ection of Fluid Flow in Porous Media. Online Journal of Earth Sciences, 3: 14-22.
17. O.I. Popoola , J.A. Adegoke and O.O Alabi , (2007). A Laboratory Study of the Effects of Porosity on the Deviation from Darcy`s Law in Saturated Porous Media. Research Journal of Applied Sciences, 2: 892-899.