Heat and Mass Transfer in a Solar Dryer with Biomass Backup Burner

Authors: Andrew R.H. Rigit, Patrick T.K. Low

Abstract:

Majority of pepper farmers in Malaysia are using the open-sun method for drying the pepper berries. This method is time consuming and exposed the berries to rain and contamination. A maintenance-friendly and properly enclosed dryer is therefore desired. A dryer design with a solar collector and a chimney was studied and adapted to suit the needs of small-scale pepper farmers in Malaysia. The dryer will provide an environment with an optimum operating temperature meant for drying pepper berries. The dryer model was evaluated by using commercially available computational fluid dynamic (CFD) software in order to understand the heat and mass transfer inside the dryer. Natural convection was the only mode of heat transportation considered in this study as in accordance to the idea of having a simple and maintenance-friendly design. To accommodate the effect of low buoyancy found in natural convection driers, a biomass burner was integrated into the solar dryer design.

Keywords: Computational fluid dynamics, heat and masstransfer, solar dryer.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1329412

References:

[1] R.K. Goyal and G.N. Tiwari, "Parametric study of a reverse flat plate absorber cabinet dryer: A new concept," Solar Energy, vol. 60, pp. 41- 48, 1997.
[2] A.K. Mahapatra and I. Imre, " Parameter sensitivity analysis of a directly irradiated solar dryer with integrated collector," Solar Energy, vol. 59, pp. 227-231, 1997.
[3] M.A. Hossain and B.K. Bala, "Drying hot chili using solar tunnel drier," Solar Energy, vol. 81, pp. 85-92, 2007.
[4] A. Ayensu, "Dehydration of food crops using a solar dryer with convective heat flow," Solar Energy, vol. 59, pp. 121-126, 1997.
[5] F.K. Forson, M.A.A. Nazha and H. Rajakaruna, "Modeling and experimental studies on a mixed mode natural convection solar crop dryer," Solar Energy, vol. 81, pp. 346-357, 2007.
[6] B. Bena and R.J. Fuller, "Natural convection solar dryer with biomass backup heater," Solar Energy, vol. 72, pp. 75-83, 2002.
[7] A. Madhlopa and G. Ngwalo, "Solar dryer with thermal storage and biomass backup heater," Solar Energy, vol. 81, pp. 449-462, 2007.
[8] H.H. Chen, C.E. Hernandez and T.C. Huang, "A study of the drying effect on lemon slices using a closed-type solar dryer," Solar Energy, vol. 78, pp. 97-103, 2005.
[9] P. Purohit, A. Kumar and T.C. Kandpal, "Solar drying versus open sun drying: A framework for financial evaluation," Solar Energy, vol. 80, pp. 1568-1579, 2006.
[10] A.G. Ferreira, C.B. Maia, M.F.B. Cortez and R.M. Valle, "Technical feasibility assessment of a solar chimney for food drying," Solar Energy, vol. 82, pp. 198-205, 2008.
[11] CD-Adapco. STAR-CD Version 4.02 Methodology. Computational Dynamics Limited, Japan, 2001.