Energy and exergy analysis of a natural convection dryer with and without sensible heat storage medium

In the present work, thermodynamic analysis of a natural convection dryer with and without sensible heat storage material (pebbles) has been studied. The purpose of this study is to enhance the performance of the dryer by using pebbles as a sensible heat storage medium. Energy and exergy analysis has been done to investigate the magnitude of losses whether the pebbles will be appropriate to use as a sensible heat storage material. The experiments were performed under different experimental conditions, without pebbles (case-I), pebbles filled up to the furnace height (case-II), pebbles filled up to the paraffin wax tray (case-III). In the case-IV, pebbles filled up to the paraffin wax tray but hot air is not allowed to flow from the rectangular chamber to the drying chamber. From the 1st three cases (I to III), it was observed that the energy losses and exergy destruction in the rectangular chamber are lower in the case-III. From the result, it can be seen that the use of sensible heat storage material and restricting the hot air in the rectangular chamber is promising in contributing to the performance of the dryer.