Flow uniformity assessment in a multi-chamber cabinet of a hybrid solar dryer

Abstract

Solar drying is an important industrial technology with expanding segment in the industrial solar market. The main drawback in commercializing solar dryers is the non-appropriate design of the drying chamber to perform uniform drying and hence producing a nonhomogeneous product. Uniformity of airflow inside the drying chamber has a significant role in the drying process. The current article presents an experimental and computational analysis of a hybrid solar-thermal dryer with a multi-chamber drying cabinet. A prototype was designed and fabricated to including three separate chambers, and each has one angular-movable tray for experimental measurements. The computational model was developed in ANSYS Fluent software for CFD simulation and validated by comparing the experimental results. A statistical analysis of the simulation results has been performed. The focus was made on the effect of tray inclination angle, 0°, 10°, 20°, 30° and 35°, air velocity and turbulence intensity distribution inside the drying cabinet at various operational conditions. Experimental and numerical analysis results indicate that the best uniformity is achieved in the tray with 30° inclination. Statistical analysis results revealed that around 93% of velocity frequency is obtained at 0.7–0.8 m/s air velocity level for 30° tray angle.