Optimising building design for cinnamon oil refinery centres: a study of air circulation and occupational safety

Abstract

Cinnamon oil refinery centres in Sri Lanka are commonly operated in naturally ventilated, semi-enclosed buildings where boilers, steam distillation units and cinnamon leaf storage can create localised heat accumulation and weak airflow regions. This study optimised the building design of such refinery centres by evaluating existing layout conditions, measured thermal and airflow data and computational fluid dynamics (CFD)-based design alternatives. Twelve refinery centres were initially observed and one representative refinery at Berathuduwa, Galle was selected for detailed investigation. Field data were used to prepare and validate an ANSYS Fluent model. The validated model was then applied to compare design variants including storage arrangement, boiler relocation, inlet opening, outlet opening, inlet-outlet combination, monitor roof, roof rise and optimised layouts. Results showed that one-sided ventilation improvements were not sufficient. The best performance was obtained by combining a clear inlet to outlet airflow corridor, non-obstructive storage placement, side-based boiler location and supportive roof volume. The study proposes practical guidelines for improving natural ventilation, reducing worker-zone thermal exposure and supporting occupational safety in small- and medium-scale cinnamon oil refinery centres.