Comprehensive Analysis of Solar Dryer with a Natural Draught

ABSTRACT

A solar dryer has been examined critically by using a constant drying model. The effect of the dynamic losses, intrinsic properties such as thermodynamic, hydrodynamic and psychometric factors, and natural draught during the practical application of the solar drying unit has been investigated. Carson and Moses, and the dynamic and static pressure correlations with the flow field have been used to determine the flow pattern inside the collector, the drying chamber, and the chimney. The energy allocation throughout the drying process has been evaluated by a Sankey diagram. The psychrometric calculation has been made by applying the steady-state-steady flow conditions (SSSF) on the carrier fluid (air). The average drying rate for the given design is 0.31 kg·h⁻¹. The overall drying system efficiency is found to be 19%. The net static-regain (S.R) in the ducting system due to the sudden expansion is 2.22 N·m⁻². The plume height for an efficient dilution of outgoing hot air is 1.17 m in addition to the given design. The flat plate collector efficiency for the given design was 26%. The surface temperature of the specimen should not be more than 321 K during a constant rate period. The pressure loss due to sudden contraction was found to be 73.48% lower than that of sudden expansion. Drying consumed 0.3% of the global irradiance for the drying purpose, whereas 57% of net received energy was absorbed by carrier fluid. The study encompassed the variability in the input that influence the performance of the solar collector since quantitative workout might not be effective unless the rheology is considered.

KEYWORDS:

• Thermal
• heat transfer
• hydrodynamics
• psychrometry
• solar
• drying
• collector

CRediT author statement

Alok Dhaundiyal: Conceptualization, Formal Analysis, Methodology, Writing – Original draft preparation (Partial), Supervision, Software, Writing – Reviewing and Editing; Gedion H. Gebremichael: Data curation, Writing – Original draft preparation (Partial), Software. Divine Atsu: Writing – Original draft preparation (Partial).

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Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

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Notes on contributors

Alok Dhaundiyal

Alok Dhaundiyal has completed his M.Tech with a major in Thermal Engineering from Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India, in 2014.  The author’s area of expertise is in thermal engineering applications, applied mathematics, and biomass waste management.  He has been awarded the Graduate Aptitude Test Engineering (GATE) fellowship by the Govt. of India. In 2017,  the Faculty of Engineering Excellence Award bestowed upon him by the University of Strathclyde, Scotland, United Kingdom. He is a member of the American Chemical Society, the American Society of Mechanical Engineers and the International Solar Energy Society.

Gedion H. Gebremichael

Gedion H. Gabremichael received his B.E. degree (Mechanical Engineering) from Asmara University in 2002 and his M. Tech degree from Chongqing University, China in 2012. He is currently working on experimental and numerical analysis of solar dryers for drying agricultural products.

Divine Atsu

Atsu Divine obtained his B.Sc. degree from the University of Cape Coast, Ghana, in 2002 and received the MSc degree in Solar Energy Engineering from the University of Dalarna, Borlange, Sweden. He is currently a PhD researcher in Mechanical Engineering (Solar Energy) at the Szent Istvan University, Godollo, Hungary. He has been a lecturer at Koforidua Technical University, Koforidua, Ghana, from 2010 to date. His research interests include technical development and sustainability of second-generation energy sources, data analytics for determining PV system performance, power system planning for PV system penetration.