CFD Simulation of Airflow Distribution in a Heat Pump-Assisted Deep-Bed Paddy Dryer

What is it about?

Heat pump dryers are extensively utilized for drying agricultural products due to their ability to operate at lower temperatures in commercial-scale settings. However, deep-bed heat pump drying (HPD) often results in uneven drying due to inadequate airflow distribution within the drying chamber. Optimal design of a heat pump dryer system can mitigate non-uniform drying and improve dryer efficiency. This study aimed to examine the airflow distribution in a deep bed of rough rice during drying using a heat pump, employing Computational Fluid Dynamics (CFD). Mathematical models incorporating the Navier-Stokes equation, heat transfer equation, and Fick's Law were utilized to simulate air velocity, temperature, and relative humidity, respectively. The COMSOL Multiphysics simulation program v5.4 was employed to solve these models, considering boundary conditions such as inlet velocity, inlet temperature, and drying air moisture content. The simulation predicted the temperature and humidity of the drying air at three different locations within the dryer throughout the drying process. Experimental data were then used to verify the simulated results.

Featured Image

Photo by siva guru on Unsplash

Photo by siva guru on Unsplash

Why is it important?

These results suggest that the developed simulation model can effectively predict air temperature and relative humidity with reasonable accuracy.