Optimization analysis of the length of baffles for solar air heaters based on CFD

ABSTRACT

Incorporating baffles was demonstrably efficacious in augmenting the functionality of solar air heaters (SAHs). A duly validated mathematical model is formulated for SAHs with baffles, aimed at the optimization of baffle length (L_b). Our findings demonstrated that with air velocity (v) spanning from 0.5 to 3.0 m·s⁻¹ and baffle length (L_b) varying between 150 and 750 mm, a discernible rise in pressure loss ensued. This phenomenon is ascribed to the extension of baffles, resulting in escalated air velocity and heightened vortex intensity. In the range of v = 0.5 ~ 3.0 m·s⁻¹, the collection efficiency evinced a marked surge by 4.61% to 11.32% when L_b traversed from 150 to 450 mm, while the collection efficiency tended to be constant as L_b exceeded 450 mm. A holistic evaluation of both pressure loss and heat collection efficiency culminates in the deduction that the pinnacle of operational effectiveness, measuring 60.78%, was attained at Lb = 600 mm and v = 3.0 m·s⁻¹. The economic scrutiny of baffled SAHs unveiled a Coefficient of Useful Energy (Cue) of a mere 0.057￥·kwh⁻¹, notably inferior to that resultingensuing from the incineration of fossil fuels under the conditions of v = 3.0 m·s⁻¹ and Lb = 600 mm.

KEYWORDS:

• Solar air heaters
• collection efficiency
• exergy efficiency
• economic
• pressure loss

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Natural Science Foundation of Shandong Province [ZR2022ME015] and the Doctoral Research Foundation of Shandong Jianzhu University.

Notes on contributors

Yuan Chang

Yuan Chang is a doctoral student at School of Architecture and Urban Planning, Shandong Jianzhu University, and a lecturer at School of Art, Shandong Management University.

Tian Mu

Tian Mu is a lecturer at School of Art, Shandong Jianzhu University.

Binguang Jia

Binguang Jia is a doctoral student student at School of Thermal Engineering, Shandong Jianzhu University.