Numerical investigation of the spiral solar air heater performance

Document Type : Research Article

Author

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

Abstract

This paper presents a new design of a spiral solar air heater with a 90 turning of the air inside the passageway assembled between the absorber and bottom plate for the purposes of mixing process and extending the surface of heat transfer that finally leads to higher performance. To enhance the thermal efficiency, an air gap is considered at the top of the solar collector to reduce heat loss. The proposed solar collector is simulated numerically by the Finite Element Method using the COMSOL software. The set of governing equations for both forced and free convection turbulent air flows are solved based on the RNG k–ε turbulence model. In the energy equation solution, the effect of surface-to-surface radiation as an important phenomenon in solar collectors is considered. Numerical results reveal a high thermal efficiency of 75% for the test case with 100  solar heat flux and air mass flow rate of 0.01 kg/s. Compared to the conventional smooth duct solar air heater with 35% thermal efficiency, the designed solar collector operates with higher performance, and a more than 100% increase in thermal efficiency is achieved due to the applied technique with the limitation of pressure drop which is increases about three times in spiral solar air heater.

Keywords

Main Subjects

References

[1] B. kumar Ahirwar, Review on different techniques used to enhance the thermal performance of solar air heater, International Journal of Heat and Mass Transfer, 220 (2024) 124979.
[2] O. Manca, S. Nardini, D. Ricci, Numerical study of air forced convection in a rectangular channel provided with ribs, in:  International Heat Transfer Conference, 2010, pp. 861-870.
[3] S. Singh, S. Chander, J. Saini, Heat transfer and friction factor correlations of solar air heater ducts artificially roughened with discrete V-down ribs, Energy, 36(8) (2011) 5053-5064.
[4] Y. Sheikhnejad, S.A.G. Nassab, Enhancement of solar chimney performance by passive vortex generator, Renewable Energy, 169 (2021) 437-450.
[5] P. Naphon, Effect of porous media on the performance of the double-pass flat plate solar air heater, International communications in heat and mass transfer, 32(1-2) (2005) 140-150.
[6] S. Singh, Utilising fractional porous interface for high thermal performance of serpentine wavy channel solar air heater, Applied Thermal Engineering, 205 (2022) 118044.
[7] S.P. Shetty, N. Madhwesh, K.V. Karanth, Numerical analysis of a solar air heater with circular perforated absorber plate, Solar Energy, 215 (2021) 416-433.
[8] O.R. Alomar, H.M. Abd, M.M.M. Salih, Efficiency enhancement of solar air heater collector by modifying jet impingement with v-corrugated absorber plate, Journal of Energy Storage, 55 (2022) 105535.
[9] S. Gandjalikhan Nassab, Efficient design of converged ducts in solar air heaters for higher performance, Heat and Mass Transfer, 59(3) (2023) 363-375.
[10] S. Gandjalikhan Nassab, Three-dimensional CFD analysis of solar air heaters for improving thermal performance using converged air ducts, International Journal of Green Energy, 21(1) (2024) 43-53.
[11] 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) 031008.
[12] M.M. Addini, S.G. Nassab, Utilization of vortex flow pattern in the design of an efficient solar air heater, Solar Energy, 276 (2024) 112683.
[13] K. Matrawy, Theoretical analysis for an air heater with a box-type absorber, Solar energy, 63(3) (1998) 191-198.
[14] N. Moummi, S. Youcef-Ali, A. Moummi, J. Desmons, Energy analysis of a solar air collector with rows of fins, Renewable energy, 29(13) (2004) 2053-2064.
[15] X. Li, Design and Test of a Serpentine Double Channel Flat Plate Solar Air Heater, Bayi Agricultural University,  (2017).
[16] B. Jia, F. Liu, D. Wang, Experimental study on the performance of spiral solar air heater, Solar Energy, 182 (2019) 16-21.
[17] B. Jia, F. Liu, X. Li, A. Qu, Q. Cai, Influence on thermal performance of spiral solar air heater with longitudinal baffles, Solar Energy, 225 (2021) 969-977.
[18] B. Jia, L. Yang, L. Zhang, B. Liu, F. Liu, X. Li, Optimizing structure of baffles on thermal performance of spiral solar air heaters, Solar Energy, 224 (2021) 757-764.
[19] W.B. Amara, A. Bouabidi, Experimental studies and 3D simulations for the investigation of thermal performances of a solar air heater with different spiral-shaped baffles heights, Journal of Building Engineering, 65 (2023) 105662.
[20] D.P.D. Fran P. Incropera, Introduction To Heat Transfer, 4 ed., Wiley, 2001.
[21] M. Tabatabaian, CFD Module: Turbulent Flow Modeling, Mercury Learning and Information, 2015.
AUT Journal of Mechanical Engineering
Volume 9, Issue 1
2025
Pages 3-18

Files

Share

How to cite

Statistics