Investigation of Gas Radiation Effect on Thermal Behavior of Solar Gas Heaters under High Irradiation

Document Type : Research Article


Mechanical Engineering Department, School of Engineering, Shahid Bahonar University of Kerman, Kerman, Iran


Based on the global consensus on mitigation of greenhouse gas and human footprint as well as improvement of engineering application sustainability, the mission of this study dedicated to the numerical simulation of plane solar gas heaters under different solar irradiation for both radiating and non radiating working gases. In numerical simulation, the continuity and momentum equations for the gas flow were solved by the finite volume method (FVM) using the SIMPLE algorithm, and the energy equation for the forced convection gas flow coupled with the conduction equation for solid parts have been solved by the finite difference method (FDM). The intensity of radiation in participating gas flow was computed by numerical solution of the radiative transfer equation (RTE) with the discrete ordinate method (DOM). It is seen thatl that increasing in gas optical thickness causes significant reduction in temperature difference between the absorber plate and flowing gas, especially at high solar irradiation. In the cases of using radiative gas with optical thickness of 0.2, instead the non participating gas, numerical results show 55%, 64% and 77% improvement in the gas temperature increase along the heater under the incidence of 900 W/m^2, 1100 W/m^2 and 1400 W/m^2, respectively. This makes the heat transfer more reversible that leads to high performance. Comparison between the present numerical results with experimental data shows good consistency.


Main Subjects

[1] O.V. Ekechukwu, B. Norton, Review of solar-energy drying systems II: an overview of solar drying technology, Energy conversion and management, 40(6) (1999) 615-655.
[2] R. Kumar, M.A. Rosen, Performance evaluation of a double pass PV/T solar air heater with and without fins, Applied Thermal Engineering, 31(8-9) (2011) 1402-1410.
[3] A.E. Kabeel, M.H. Hamed, Z. Omara, A. Kandeal, Solar air heaters: Design configurations, improvement methods and applications–A detailed review, Renewable and Sustainable Energy Reviews, 70 (2017) 1189-1206.
[4] S. Chamoli, R. Chauhan, N. Thakur, J. Saini, A review of the performance of double pass solar air heater, Renewable and Sustainable Energy Reviews, 16(1) (2012) 481-492.
[5] H. Mzad, K. Bey, R. Khelif, Investigative study of the thermal performance of a trial solar air heater, Case Studies in Thermal Engineering, 13 (2019) 100373.
[6] M. Atashafrooz, S.A.G. Nassab, Combined heat transfer of radiation and forced convection flow of participating gases in a three-dimensional recess, Journal of Mechanical Science and Technology, 26(10) (2012) 3357-3368.
[7] M. Atashafrooz, S.G. Nassab, Simulation of three-dimensional laminar forced convection flow of a radiating gas over an inclined backward-facing step in a duct under bleeding condition, Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 227(2) (2013) 332-345.
[8] M. Foruzan Nia, S.A. Gandjalikhan Nassab, A.B. Ansari, Numerical simulation of flow and thermal behavior of radiating gas flow in plane solar heaters, Journal of Thermal Science and Engineering Applications, 12(3) (2020).
[9] M.F. Modest, Radiative heat transfer, Academic press, 2013.
[10] S.V. Patankar, D.B. Spalding, A calculation procedure for heat, mass and momentum transfer in three-dimensional parabolic flows, in:  Numerical prediction of flow, heat transfer, turbulence and combustion, Elsevier, 1983, pp. 54-73.
[11] F. Chabane, N. Moummi, A. Brima, Experimental study of thermal efficiency of a solar air heater with an irregularity element on absorber plate, International Journal of Heat and Technology, 36 (2018) 855-860.