Energy and exergy analyses of thin layer drying of tomato in a forced Solar Dryer

In this paper the energy and exergy analyses in chamber drying process of thin layer drying of tomato in a forced solar drying was investigated. The experiments were carried out with two thicknesses of 5 and 7 and two airflows 0. 5 m. s-1 and 1 m. s-1. During the experimental process، ambient temperature was between 22 and 36، air relative humidity between was 14 and 50، and solar radiation ranged from 150 to 850 W. m-2. The effects of drying variables on energy utilization، energy utilization ratio، exergy loss and exergy efficiency were studied by applying the first law of thermodynamics. In chamber drying at airflow of 1 m. s-1 and thickness of 5mm،the values of energy utilization، energy utilization ratio، exergy loss and exergy efficiency varied from 6. 62 to 152. 72W، 0. 02 to 0. 45، 2. 42 to 32W and 32 to 80، Respectively. In addition، the results showed that both energy utilization rate and exergy loss efficiency of the drying chamber decreased with increasing drying mass flow rate and drying thickness while the exergetic efficiency and energy utilization of the drying chamber increased.