Research Article
Shyam, GN Tiwari
Abstract
In this communication, an attempt has been made to evaluate the performance of mixed mode dryer consists of PVT air collectors and wooden made drying chamber with load condition. Based on energy balances of PVT air collectors and conventional collector, an expression for outlet air temperature of PVT air collector has been derived. Further by using the rate of thermal energy available from PVT air collector, an analytical expression for crop temperatures has also been derived in terms of design and climatic parameters of New Delhi and experimentally validated. The validation of analytical model has been carried out for cauliflower with thin layer drying for last day of drying with reasonable assumptions. It has been observed that the drying time for a half kilogram of cauliflower is achieved in 21 hours due to larger size of the samples. The annual overall thermal energy and exergy were 396.48 kWh and 46.52 kWh respectively. The energy payback time (EPBT) was increased from 3.17 years on thermal energy basis to 27.03 years on exergy basis for mixed mode dryer. The energy production factor and life cycle conversion efficiency were found to be smaller on exergy basis compared to thermal energy basis. For a life time of 30 year the carbon credits earned on overall thermal energy basis was $ 727.9 and on overall exergy basis it was $ 85.5.