Drying uniformity analysis of an indirect solar dryer based on computational fluid dynamics and image processing


Benhamza A., Boubekri A., Atia A., Hadibi T., ARICI M.

SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS, vol.47, 2021 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 47
  • Publication Date: 2021
  • Doi Number: 10.1016/j.seta.2021.101466
  • Title of Journal : SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS
  • Keywords: Distribution, Solar drying, Uniform drying, Image processing, CFD simulation, CABINET DRYER, BITTER GOURD, AIR HEATER, CFD, PERFORMANCE, IMPROVEMENT, SIMULATION, DESIGN, ENERGY, OPTIMIZATION

Abstract

Indirect solar dryer is used to dry food products. The dried product quality and the drying air temperature distribution are inter-related parameters. Therefore, obtaining a suitable air distribution in the drying chamber via parametric studies is essential to ensure uniform drying of products. Since parametric and optimization investigations by physical experiments are usually expensive and time consuming, computational fluid dynamics (CFD) being a flexible and less expensive tool can be employed to perform such studies. In the current paper, the best design and operating conditions are highlighted through a parametric study using an experimentally validated CFD model and image processing techniques. The effect of adding a passive chimney and the effect of three mass flow rates on the drying air distribution is tested by using ANSYS FLUENT software. The average temperature increased by 16, 11 and 8 K for the mass flow rate of (m) over dot = 0.0141, 0.0636, and 0.0872 kg.s (-1), respectively. The air temperature uniformity was improved significantly by 21.7 and 20.3% for the mass flow rate of (m) over dot =0.0141 and 0.06 kg.s (-1), respectively, while it was marginally increased for (m) over dot = 0.08 kg.s (-1). Using solar chimney improved the drying air temperature by 7 degrees.