Performance of North Wall Modified Passive and Active Greenhouse Groundnuts Dryers

An even-span greenhouse groundnuts dryer having a reflective north wall has been developed and tested under passive and active modes. The effects of varying sample mass (580, 880, and 1180 g) on the thermal and enviro-economic performance indicators of the dryer have been investigated. The Nusselt number expression, embodied energy (EE), and capital cost (C_c) were used for thermal, environmental, and economic assessment of the dryer. The drying behavior of the groundnuts samples has also been estimated using the moisture ratio in drying models. Thermal indicators were observed to increase with increased sample mass and were found higher under active mode. The values of EE and C_c of the dryer under passive and active modes were 145.24 and 158.42 kWh, and INR 1257.11 and INR 2157.11, respectively. Enviro-economic indicators were also observed to improve with increased sample mass and were comparable for both the passive and active modes. The moisture ratio for all the samples shows an excellent fit with the Midilli–Kucuk model. An average Midilli–Kucuk model has been recommended to predict the drying behavior of groundnuts in the developed greenhouse dryer.