OPEN ACCESS
In this current contribution, a parametric investigation of air flow rate at the inlets of solar air collector was carried out. Through a developed Matlab code effort was made to show the effect of the air flow rate on solar collector outlet temperature. From the simulation results a database of outlet temperature and corresponding flow rate variation with time was created. Then, isotherm contours were deduced and plotted. For drying temperature kept constant at a given value regardless the meteorological conditions fluctuation, the flow rate variation with time was fitted by smoothing spline function. The simulation study was done for three different meteorological scenarios: Clear sky day, partly cloudy day and cloudy day. It has been found also that drying with variable flow rate at optimum temperature equal to 50 ±1°C the amount of air that was aspired at the inlet was 1207.8 kg. By contrast, drying with constant flow rate a total 625.5kg of air was aspired and it might result in fluctuation in drying temperature which affects the dried product quality. Thus variable flow rate allows a gain ratio in the aspired air amount of 93% and better product quality. This is valid for clear sky day. In case of partly and cloudy day, flow rate gain ratio was 104% and 78% respectively.
solar drying, mathematical modeling, numerical simulation, parametric investigation, optimal air mass flow rate
[1] Karim MA, Hawlader MNA. (2006). Performance evaluation of a v-groove solar air collector for drying applications. Applied Thermal Engineering 26(1): 121. http://dx.doi.org/10.1016/j.applthermaleng.2005.03.017
[2] Varalakshmi K. (2016). Role of conventional energy in rural development in India: feasibility analysis of solar drying technology. International Journal of Energy and Environmental Engineering 7(3): 321. http://dx.doi.org/10.1007/s40095-016-0210-8
[3] El-Sawi AM, Wifi AS, Younan MY, Elsayed EA, Basily BB. (2010). Application of folded sheet metal in flat bed solar air collectors. Applied Thermal Engineering 30(8-9): 864. http://dx.doi.org/10.1016/j.applthermaleng.2009.12.018
[4] Yeh HM, Lin TT. (1996). Efficiency improvement of flat-plate solar air heaters. Energy 21(6): 435. http://dx.doi.org/10.1016/0360-5442(96)00008-4
[5] Choudhury C. (1988). A solar air heater for low temperature applications. Sol Energy 40(4): 335. http://dx.doi.org/10.1016/0038-092X(88)90006-0
[6] Hollands KGT. (1963). Directional selectivity, emittance, and absorptance properties of vee corrugated specular surfaces. Solar Energy 7(3): 108. http://dx.doi.org/10.1016/0038-092X(63)90036-7
[7] Gao W, Lin W, Liu T, Xia C. (2007). Analytical and experimental studies on the thermal performance of cross-corrugated and flat-plate solar air heaters. Applied Energy 84(4): 425. http://dx.doi.org/10.1016/j.apenergy.2006.02.005
[8] Alvarez G, Arce J, Lira L, Heras MR. (2004). Thermal performance of an air solar collector with an absorber plate made of recyclable aluminum cans. Solar Energy 77(1): 107. http://dx.doi.org/10.1016/j.solener.2004.02.007
[9] Moummi N, Youcef-Ali S, Moummi A, Desmons JY. (2004). Energy analysis of a solar air collector with rows of fins. Renewable Energy 29(13): 2053. http://dx.doi.org/10.1016/j.renene.2003.11.006
[10] Patil AK, Saini JS, Kumar K. (2012). Heat transfer and friction characteristics of solar air heater duct roughened by broken V-shape ribs combined with staggered rib piece. Journal of Renewable and Sustainable Energy 4(1): 013115. http://dx.doi.org/10.1063/1.3682072
[11] Sharma A, Varun, Kumar P, Bharadwaj G. (2013). Heat transfer and friction characteristics of double pass solar air heater having V-shaped roughness on the absorber plate. Journal of Renewable and Sustainable Energy 5(2): 023109. http://dx.doi.org/10.1063/1.4794747
[12] Ravi RK, Saini RP. (2016). Experimental investigation on performance of a double pass artificial roughened solar air heater duct having roughness elements of the combination of discrete multi V shaped and staggered ribs. Energy 116: 507. http://dx.doi.org/10.1016/j.energy.2016.09.138
[13] Lanjewar AM, Bhagoria JL, Agrawal MK. (2015). Review of development of artificial roughness in solar air heater and performance evaluation of different orientations for double arc rib roughness. Renewable and Sustainable Energy Reviews 43: 1214. http://dx.doi.org/10.1016/j.rser.2014.11.081
[14] Nayak RK, Singh SN. (2016). Effect of geometrical aspects on the performance of jet plate solar air heater. Solar Energy 137: 434. http://dx.doi.org/10.1016/j.solener.2016.08.024
[15] Goel AK, Singh SN. (2017). Thermal performance of solar air heater using jet impingement technique with longitudinal fins. Journal of Scientific and Industrial Research 76(12): 780. http://nopr.niscair.res.in/handle/123456789/43196
[16] Abene A, Dubois V, Le Ray M, Ouagued A. (2004). Study of a solar air flat plate collector: use of obstacles and application for the drying of grape. Journal of Food Engineering 65(1): 15. http://dx.doi.org/10.1016/j.jfoodeng.2003.11.002
[17] Singh SN. (2006). Performance studies on continuous longitudinal fins solar air heater. Journal of ISM Dhanbad 2: 39.
[18] Goel AK, Singh SN. (2017). Performance studies of a jet plate solar air heater with longitudinal fins. International Journal of Ambient Energy https://doi.org/10.1080/01430750.2017.1372808
[19] Giovanni T. (2011). Performance of solar air heater ducts with different types of ribs on the absorber plate. Energy 36(11): 6651. http://dx.doi.org/10.1016/j.energy.2011.08.043
[20] Arunachalam UP, Edwin M. (2017). Experimental investigations on thermal performance of solar air heater with different absorber plates. International Journal of Heat and Technology 35(2): 393. http://dx.doi.org/10.18280/ijht.350223
[21] Saha SN, Sharma SP. (2017). Performance evaluation of corrugated absorber double flow solar air heater based on energy, effective and exergy efficiencies. International Journal of Mechanical & Mechatronics Engineering 17(1): 63
[22] Kundu B. (2008). Performance and optimum design analysis of an absorber plate fin using recto-trapezoidal profile. Solar Energy 82(1): 22. http://dx.doi.org/10.1016/j.solener.2007.05.002
[23] Lim YY, Lim TT, Tee JJ. (2007). Antioxidant properties of several tropical fruits: A comparative study. Food Chemistry 103(3): 1003. http://dx.doi.org/10.1016/j.foodchem.2006.08.038
[24] Omolola AO, Jideani AI, Kapila PF. (2017). Quality properties of fruits as affected by drying operation. Critical Reviews in Food Science and Nutrition 57(1): 95. http://dx.doi.org/10.1080/10408398.2013.859563
[25] Oliveira MS, Ramos IN, Brandão TRS, Silva CLM. (2015). Effect of air-drying temperature on the quality and bioactive characteristics of dried galega kale (brassica oleracea l. var. acephala). Journal of Food Processing and Preservation 39(6): 2485. http://dx.doi.org/10.1111/jfpp.12498
[26] Vega-Galvez A., Scala KD, Rodriguez K, Lemus-Mondaca R, Miranda M, Lopez J, Perez-Won M. (2009). Effect of air-drying temperature on physico-chemical properties, antioxidant capacity, colour and total phenolic content of red pepper (Capsicum annuum, L. var. Hungarian). Food Chemistry 117(4): 647. http://dx.doi.org/10.1016/j.foodchem.2009.04.066
[27] Pendre NK, Nema PK, Sharma HP, Rathore SS, Kushwah SS. (2012). Effect of drying temperature and slice size on quality of dried okra (Abelmoschus esculentus (L.) Moench). Journal of Food Science and Technology 49(3): 378. http://dx.doi.org/10.1007/s13197-011-0427-8
[28] Icier F. (2010). Ohmic blanching effects on drying of vegetable byproduct. Journal of Food Process Engineering 33(4): 661. https://doi.org/10.1111/j.1745-4530.2008.00295.x
[29] Korus A. (2011). Effect of preliminary processing, method of drying and storage temperature on the level of antioxidants in kale (Brassica oleracea L. var. acephala) leaves 44(8): 1711. http://dx.doi.org/10.1016/j.lwt.2011.03.014
[30] Kaya A, Aydına O, Kolaylı S. (2010). Effect of different drying conditions on the vitamin C (ascorbic acid) content of Hayward kiwifruits (Actinidia deliciosa Planch). Food and Bioproducts Processing 88(2-3): 165. http://dx.doi.org/10.1016/j.fbp.2008.12.001
[31] Youcef-Ali S, Desmons JY. (2007). Influence of the aerothermic parameters and the product quantity on the production capacity of an indirect solar dryer. Renewable Energy 32(3): 496. http://dx.doi.org/10.1016/j.renene.2006.05.004
[32] Fudholi A, Sopian K, Ruslan MH, Othman MY. (2013). Performance and cost benefits analysis of double-pass solar collector with and without fins. Energy Conversion and Management 76: 8. http://dx.doi.org/10.1016/j.enconman.2013.07.015
[33] Sopian K, Alghoul MA, Alfegi EM, Sulaiman MY, Mus EA. (2009). Evaluation of thermal efficiency of double-pass solar collector with porous–nonporous media. Renewable Energy 34(3): 640. https://doi.org/10.1016/j.renene.2008.05.027
[34] Agbossou K, Tetang FA, Boroze TE, N’wuitcha K, Napo K, Zeghmati B. (2016). Theoretical and experimental study of thermal performance of flat plate air heating collector. International Journal of Science and Technology 5(10): 473.
[35] Sopian K, Yigit KS, Liu HT, Kaka S, Veziroglu TN. (1996). Performance analysis of photovoltaic thermal air heaters. Energy Conversion and Management 37(11): 1657. http://dx.doi.org/10.1016/0196-8904(96)00010-6
[36] El Khadraoui A, Bouadila S, Kooli S, Guizani A, Farhat A. (2016). Solar air heater with phase change material: An energy analysis and a comparative study. Applied Thermal Engineering 107: 1057. http://dx.doi.org/10.1016/j.applthermaleng.2016.07.004
[37] Harrouni S. (2008). Fractal classification of typical meteorological days from global solar irradiance: application to five sites of different climates. In: Badescu V (ed) Modelling solar radiation at the Earth surface. Springer, Berlin. pp. 29-54.
[38] Padovan A, Col DD. (2010). Measurement and modeling of solar irradiance components on horizontal and tilted planes. Solar Energy 84(12): 2068. http://dx.doi.org/10.1016/j.solener.2010.09.009
[39] Daguenet M. (1985). Les Séchoirs Solaires: Théorie et Pratique, edition de l'UNESCO. Paris.
[40] McAdams, William H. (William Henry). (1954). Heat transmission, third ed., McGraw Hill, New York. https://trove.nla.gov.au/version/12307044
[41] Duffie JA, Beckman WA. (1980). Solar Engineering of Thermal Processes. 0th edition., John Wiley and Sons, New York, pp. 398-402.
[42] Yeh HM, (1992). Theory of baffled solar air heaters. Energy 17(7): 697. http://dx.doi.org/10.1016/0360-5442(92)90077-D
[43] Ramesh KS, Dusan PS. (2003). Fundamentals of heat exchanger design, first ed., John Wiley & Sons, New Jersey, Canada.
[44] Sparrow EM, Ramsey JW, Mass EA. (1979). Effect of Finite Width on Heat Transfer and Fluid Flow about an Inclined Rectangular Plate. Journal of Heat Transfer 101(2): 199. http://dx.doi.org/10.1115/1.3450946
[45] Buchberg H, Catton I, Edwards DK. (1976). Natural convection in enclosed spaces—a review of application to solar energy collection. Journal of Heat Transfer 98(2): 182. http://dx.doi.org/10.1115/1.3450516
[46] Gnielinski V. (1976). New equations for heat and mass transfer in turbulent pipe and channel flow. International Chemical Engineering 16(2): 359.
[47] Swinbank WC. (1963). Long-wave radiation from clear skies. Quarterly Journal of the Royal Meteorological Society 89(381): 339. http://dx.doi.org/10.1002/qj.49708938105
[48] Lienhard IV JH, Lienhard V JH. (2006). A Heat Transfer Textbook, third ed., Phlogiston Press, Cambridge, Massachusetts.
[49] Manglik RM, Bergles AE. (1995). Heat transfer and pressure drop correlations for the rectangular offset strip fin compact heat exchanger. Experimental Thermal and Fluid Science 10(2): 171. http://dx.doi.org/10.1016/0894-1777(94)00096-Q
[50] Hu S, Herold KE. (1995). Prandtl number effect on offset fin heat exchanger performance: experimental results. International Journal of Heat and Mass Transfer 38(6): 1053. http://dx.doi.org/10.1016/0017-9310(94)00220-P
[51] Aoues K, Moummi N, Zellouf M, Benchabane A. (2011). Thermal performance improvement of solar air flat plate collector: a theoretical analysis and an experimental study in Biskra, Algeria. International Journal of Ambient Energy 32(2): 95. http://dx.doi.org/10.1080/01430750.2011.584469
[52] De Boor C. (1978). A Practical Guide to Splines, in Applied Mathematical Sciences, in: John F et al, ed., Springer-Verlag, New York.
[53] Fox J (2000). Nonparametric Simple Regression: Scatterplot Smoothing, ed., Sage Publications, Thousand Oaks, London, New Delhi.
[54] Shahraray B, Anderson DJ. (1989). Optimal estimation of contour properties by cross-validated regularization. IEEE Transactions on Pattern Analysis and Machine Intelligence 11(6): 600. http://dx.doi.org/10.1109/34.24794
[55] Benseddik A, Azzi A, Zidoune MN, Khanniche R, Besombes C. Empirical and diffusion models of rehydration process of differently dried pumpkin slices. Journal of the Saudi Society of Agricultural Sciences xxx (2018). https://doi.org/10.1016/j.jssas.2018.01.003
[56] © 1994-2018 The MathWorks, Inc., Evaluating Goodness of Fit, online available at: https://www.mathworks.com/help/curvefit/evaluating-goodness-of-fit.html, 2017.
[57] Naz R. (2012). Physical properties, sensory attributes and consumer preference of fruit leather. Pakistan Journal of Food Sciences 22(4): 188.
[58] Gupta PM, Das AS, Barai RC, Pusadkar SC, Pawar VG. (2017). Design and construction of solar dryer for drying agricultural products. International Research Journal of Engineering and Technology 4(3): 1946.
[59] Papade CV, Boda MA. (2014). Design & development of indirect type solar dryer with energy storing material. International Journal of Innovative Research in Advanced Engineering 1(12): 109.
[60] Abdullahi Y, Momoh M, Garba MM, Musa M. (2013). Design and construction of an adjustable and collapsible natural convection solar dryer. International Journal of Computational Engineering Research 3(6): 1.