Multiparameter Analysis of Cooling Efficiency of Ventilated Fruit Cartons using CFD: Impact of Vent Hole Design and Internal Packaging

Abstract

Forced-air cooling (FAC) efficiency of fruit packed in ventilated cartons can be considerably improved by revising vent hole design and tailoring these openings according to the internal packaging used. Current vent hole designs for fruit cartons, however, often result from trials and errors or are developed in order to improve a specific package functionality, such as fruit cooling rate. This study presents a novel multiparameter evaluation process for ventilated fruit packaging. This multi-parameter strategy evaluates cooling rate and cooling uniformity, airflow resistance and energy efficiency. Computational fluid dynamics is used to evaluate the impact of internal trays and four vent hole designs. One of the designs investigated is currently used in commercial export of apples, while the other three are new configurations proposed to improve fruit cooling efficiency. Results showed that the addition of trays to the existing commercially used Standard Vent hole design increased ventilation energy consumption by 31 % compared to cartons without trays, but in the two newly proposed carton designs (Altvent and Multivent), the energy usage was reduced by 27 and 26 %, respectively, as airflow was distributed more evenly between the five fruit layers. The use of the new vent hole designs (Altvent and Multivent) compared to the Standard Vent design, also considerably improved cooling uniformity and energy efficiency during FAC, reducing cooling heterogeneity by 79 and 51 %, as well as energy consumption by 48 and 7 %, when packed with and without trays, respectively. By simultaneous evaluation of multiple parameters, this analysis approach thus unveiled the benefits and disadvantages of the new ventilated carton designs and can be used to further improve vent hole designs for specific cold chains.