Work

Performance enhancements of a PCM-integrated triple-pass indirect solar dryer with staggered drying chamber: A CFD investigation

Year: 2026

Type: article

Abstract: Conventional indirect solar dryers suffer from low thermal efficiency and unreliable operation because of poor heat transfer and the intermittent nature of solar energy. The present work numerically investigates a novel triple-pass indirect solar dryer, a fin-enhanced phase change material (PCM) thermal energy storage (TES) unit, and a staggered drying chamber to improve heat transfer, energy storage, and air flow distribution. The thermo-hydraulic performance of the solar air heater and drying chamber was analyzed using computational fluid dynamics (CFD) by ANSYS Fluent, while the charging and discharging characteristics of the PCM-TES unit were simulated using COMSOL Multiphysics. The models were validated against experimental and published numerical data and showed good agreement. The effects of Reynolds number and airflow rate on outlet temperature, thermal efficiency, Nusselt number, pressure drop, and thermohydraulic performance parameter (THPP) were investigated. The triple-pass arrangement produced higher outlet air temperatures than the single- and double-pass arrangements. The heat transfer was significantly improved by the corrugated absorber compared to the conventional flat-plate absorber. The thermal efficiency increased from 41% to 73% as the Reynolds number increased from about 3000 to 15,200, corresponding to the investigated airflow-rate range of 0.01 - 0.07 kg/s, whereas the Nusselt number increased by 32%. The THPP was greater than unity, with a maximum of 1.29 at Re = 9000. Compared with the bare-tube configuration, incorporation of rectangular fins into the PCM-TES unit reduced the charging time by 17.2% for a TES capacity of 4.73 MJ. The proposed system therefore enhances indirect solar-drying performance.

Source: Case Studies in Thermal Engineering

DOI: 10.1016/j.csite.2026.108583

Authors: Tewodros Ayenew Eskemech, Venkata Ramayya Ancha, Getachew Shunki Tibba

Institution: Jimma University

Language: English

Topic: Heat Transfer Mechanisms

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Industry, innovation and infrastructure, Climate action

Open Access status: gold

Estimated APC paid: $1,620