Title: Energy and exergy analyses of paddy drying process in a vertical fluidised bed dryer

Authors: Binayak Pattanayak; Siba Shankar Mohapatra; Harish Chandra Das

Addresses: Department of Mechanical Engineering, Siksha 'O' Anusandhan, Deemed to be University, Bhubaneswar, 751030, India ' Department of Mechanical Engineering, Siksha 'O' Anusandhan, Deemed to be University, Bhubaneswar, 751030, India ' Department of Mechanical Engineering, National Institute of Technology, Meghalaya, 793003, India

Abstract: This research article focuses on the energy and exergy analysis of paddy drying using fluidised bed dryer. The energy analysis of paddy drying process is conducted using first law of thermodynamics. The parameters energy utilisation (EU) and energy utilisation ratio (EUR) are determined from the first law analysis. Similarly, second law of thermodynamics is used for the exergy analysis of paddy drying. Exergy analysis is conducted with the help of the parameters like exergy evaporation rate, exergy destruction and exergetic efficiency. Specific moisture extraction rate (SMER) is determined to get the value of moisture vaporisation rate per energy consumed for drying. Paddy grains are dried in a batch of 2 kg and 3 kg at 40°C, 50°C temperature of drying air and drying air velocity of 2 and 3 m/s. From the analysis, it is observed that EU, EUR, SMER and exergy destruction decreased and exergetic efficiency increased with drying time. The exergy evaporation rate first increases to a certain value from zero and then decreases continuously. The exergetic efficiency varies from 12.37% to 86.25% whereas EU and EUR varied from 55 J/s to 549 J/s and 0.087 to 0.656 respectively.

Keywords: energy; energy utilisation; energy utilisation ratio; EUR; exergy; exergy destruction; exergetic efficiency.

DOI: 10.1504/IJEX.2019.097975

International Journal of Exergy, 2019 Vol.28 No.2, pp.113 - 125

Received: 24 Apr 2018
Accepted: 09 Oct 2018
Published online: 25 Feb 2019 *

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