Determination of convective heat transfer coefficient and specific energy consumption of potato using an ingenious self tracking solar dryer.

摘要

In the present work, an attempt has been made to experimentally determine the heat transfer properties of potato in terms of convective heat transfer coefficient, specific energy consumption and specific heating rate. Drying experiments with potato cylinders have been performed in an in-house fabricated laboratory scale natural convection indirect solar dryer with self tracking mechanism. The convective heat transfer coefficient of cylindrical potato samples was evaluated by considering the combined effects of heat capacities of food product as well as radiative heat transfer from drying chamber to the food product. This study revealed that the convective heat transfer coefficient for potato cylinders was varying from 11.73 to 16.23 W/m2 degrees C with an experimental error of 7.86%. The specific energy consumption was decreasing exponentially with drying time, and the average value was estimated to be 3,491 kJ/kg. It was also observed that the specific heating rate for potato cylinders decrease with dimensionless moisture content.