Computational fluid dynamics modelling of a sustainable evaporative cooling storage system for agricultural products

Abstract

Evaporative cooling is a sustainable and energy-efficient technique for preserving perishable agricultural products, particularly in off-grid environments. However, existing studies are largely limited to small-scale systems and steady state analyzes, with limited understanding of transient heat and mass transfer behaviour in large storage configurations. This study develops and analyzes a large-scale evaporative cooling storage system using locally available porous materials such as clay, sand, and bricks. A transient three-dimensional Computational Fluid Dynamics model was implemented in ANSYS Fluent, incorporating porous media flow, species transport, and buoyancy-driven natural convection to simulate coupled heat and mass transfer within the chamber. Results indicate a temperature reduction from 310 K to 302.8 K, corresponding to a cooling effect of 7.2 °C within 8.3 h. The airflow stabilizes at approximately 0.85 m/s, promoting uniform cooling. The system demonstrates sustained evaporation-driven heat removal and an approximately 1.6-fold potential increase in shelf life based on temperature-dependent estimation. The findings highlight the coupled role of porous media evaporation and natural convection in governing thermal regulation and provide a scalable, low-cost framework for improving post-harvest storage in resource-constrained environments. Large-scale evaporative cooling storage system developed using clay–sand porous media. Transient 3D CFD model captures coupled heat and mass transfer with natural convection. Temperature reduction of 7.2 °C achieved under passive, energy-free cooling conditions. Porous media evaporation and airflow interaction enhance thermal uniformity inside chamber. Approximately 1.6× potential shelf-life improvement estimated using temperature-dependent model.