Numerical Simulation of Heat Pump Drying Process of Turmeric Slices

Heat pump drying is an advanced drying technique where the drying product is dehydrated at a low temperature. It was proved that by using both the heat source of the condenser and the heat sink of the evaporator, the drying process can be conducted with a low energy consumption. In this work, the heat and mass transfer process inside the turmeric slices during the heat pump drying process are modeled by using the concept of effective moisture diffusivity. The magnitude of effective moisture diffusivity is numerically determined by using the inverse. The developed model and the determined parameters are validated by comparing experimental data obtained at drying temperatures of 35, 40 and 45 °C. The results indicate that the effective moisture diffusivity strongly depends on both drying temperature and slice thickness. The determined effective moisture diffusivity can readily be used to optimize the design and operation procedures of the turmeric heat pump dryer.