In this paper, various aspects of solar air heaters applied to drying process are investigated. This study presents a mathematical model for simulating the transient processes which occur in solar air collectors with flat plate and V-corrugated absorbers. The proposed model is time-dependent and is based on solving equations which describe the energy conservation in partial differential forms of the components of the system.
The differential equations were solved using the implicit finite-difference method, and the simulation is carried out using MATLAB program. In order to verify the proposed method, an experiment was conducted in variable ambient conditions and flow rates on a solar air collector with a flat plate galvanized iron absorber.
The comparison between computed and measured results of outlet air temperature shows a satisfactory convergence. The simulation results are also verified with distinguished research results from literature.
The results show that the V-corrugated collector has considerably superior thermal performance than the flat plate collector of about 21.64% for single-flow mode and 17.16% for counter-flow mode. Furthermore, the model shows that the efficiency of the double-flow mode is greater than the single-flow mode by 17.01% and 12.53%, respectively, for the flat plate and V-corrugated solar air heaters.
Solar air heaters Flat plate collector V-corrugated collector Thermal efficiency
This is a preview of subscription content, log in to check access.
Duffie, J.A., Beckman, W.A.: Solar Thermal Engineering. Wiley Interscience, New York (1991)Google Scholar
El-Sebaii, A.A., Aboul-Enein, S., Ramadan, M.R.I., Shalaby, S.M., Moharram, B.M.: Investigation of thermal performance of-double pass-flat and v-corrugated plate solar air heaters. Energy. 36, 1076–1086 (2011)CrossRefGoogle Scholar
Hollands, K.G.T., Unny, T.E., Raithby, G.D., Konicek, L.J.: Free convection heat transfer across inclined air layers. ASME J. Heat Transfer. 98, 189–193 (1976)CrossRefGoogle Scholar
Karim, M.A., Hawlader, M.N.A.: Performance investigation of flat plate, v-corrugated and finned air collectors. Energy. 31, 452–470 (2006)CrossRefGoogle Scholar
Karim, M.A., Perez, E., Amin, Z.M.: Mathematical modelling of counter flow v-grove solar air collector. Renew. Energy. 67, 192–201 (2014)CrossRefGoogle Scholar
Kays, W.M., Crawford, M.E.: Convective Heat and Mass Transfer, 2nd edn. McGraw-Hill, New York (1980)Google Scholar
Mercer, W.E., Pearce, W.M., Hitchcock, J.E.: Laminar forced convection in the entrance region between parallel flat plates. J Heat Transf Trans ASME. 89, 251–257 (1967)CrossRefGoogle Scholar
Omojaro, A.P., Aldabbagh, L.B.Y.: Experimental performance of single and double pass solar air heater with fins and steel wire mesh as absorber. Appl. Energy. 87, 3759–3765 (2010)CrossRefGoogle Scholar