Effect of Phase Change Materials on the Performance of Natural Convection Indirect Type Solar Dryer during Drying Ivy Gourd

Abstract

The effect of integrating thermal energy storage (TES) unit with a natural convection indirect type solar dryer was investigated by drying ivy gourd in the dryer without TES (setup I) and with TES (setup II) provisions. Paraffin wax was filled in the concentric tubes of polycarbonate and finned aluminum to make setup II by updating setup I. The experimental data from both setups were used to estimate the drying parameters. The average collector's efficiencies were 62.6% and 63.3%. Drying efficiencies were 6.6% and 13.1% for the setup I and II, respectively. The average moisture diffusivity, mass transfer and heat transfer coefficients were 7.1 × 10⁻⁹ and 8.1 × 10⁻⁹ m²/s, 0.0033 and 0.0041 m/s and 3.9 and 4.7 W/m²K for the setup I and II, respectively. The enhancements of drying efficiency, effective diffusivity, mass and heat transfer coefficients were 98.3%, 14.2%, 24.2% and 22.1%, respectively, in setup II compared to setup I. The activation energy, average specific energy consumption, and specific moisture extraction rate were evaluated. The drying kinetics were correlated with time and moisture variations. It took 18 and 16 h to reduce the moisture content of the sample from 15.32 (db) to 0.144 (db) for the setup I and II, respectively.

Acknowledgments

The authors indebted to thank Department of Mechanical Engineering, NIT Warangal, India for supporting the project in finance which is referred as: NITW/MED/Head/2015/408 dated 3rd Dec. 2015.

Additional information

Notes on contributors

Mulatu C. Gilago

Mulatu Chake Gilago is a Ph.D. student in the Mechanical Engineering Department at the National Institute of Technology Warangal, India, under the supervision of Dr. V. P. Chandramohan. He is also a staff member in Mechanical Engineering Department at Wachemo University, Ethiopia. He received his M.Sc. degree in Materials Science from Hawassa University, Ethiopia. He is currently researching experimental investigation of solar dryers.

V. P. Chandramohan

V.P. Chandramohan is presently working as an Associate Professor in the Department of Mechanical Engineering, National Institute of Technology Warangal, India. He graduated in Mechanical Engineering from Manonmaniam Sundaranar University in 2001, completed his Master of Engineering in Thermal Power Engineering from Annamalai University in 2002, and MBA Project Management in 2009. He obtained his Ph.D. from IIT Delhi, India in 2012. His research interests are (i) computational fluid dynamics (ii) convection and conduction heat transfer (iii) drying and simultaneous solution of heat and mass transfer (iv) solar energy (v) solar updraft tower and solar vortex plant. He has more than 120 publications in International reputed journals, book chapters, and conferences. He is handling a lot of sponsored research projects from various funding sources. He got various awards such as a gold medal for ME (Thermal Power) and Dr. S. Sathik prize from Annamalai University, DST-SERB Empowerment Scheme Award 2016, and ScienceDirect TOP 25 Hottest Articles award. He is serving as editorial board member and reviewer in various reputed journals in his field of expertise.