A Computational Study on Comparative Analysis of Evaporative Cooling System and Conventional Cold Storage for Onion Preservation
摘要
Onions are a vital commodity that require effective year-round storage to maintain quality and reduce post-harvest losses. The key factors influencing the storage life of onion bulbs include temperature, air circulation, humidity, and post-harvest management practices. While cold storage at 0 °C with 65–70% relative humidity provides optimal preservation, it is associated with high initial and operational costs as well as significant energy demands. This study explores cost-effective and energy-efficient storage alternatives through computational airflow analysis using Ansys Fluent 2021 R1. Specifically, it compares conventional cold storage with a newly designed evaporative cooling storage system. The proposed system accommodates 25 tons of onions within a 165 m3 volume, maintaining temperatures between 26 and 27 °C at 70% relative humidity using 100% fresh air. The evaporative cooling system costs 176,499.42 INR in India (excluding construction and ducting), compared to 177,860.70 INR for traditional cold storage. The total heat load for cold storage was calculated at 102,000 BTU/h, while the evaporative cooling system demonstrated a significantly lower heat load of 23,328 BTU/h, both operating with an airflow of 84.95 CMM. The use of fresh air circulation in the evaporative cooling system improves storage longevity and minimizes the risk of hot spots. Furthermore, the study shows that the evaporative cooling system reduces machinery costs by 1.09% and energy consumption by 86.35% compared to conventional cold storage. These results underscore the potential of the evaporative cooling system as a sustainable and economical solution for onion storage.