CFD modelling of a fungicide thermonebulisation system for fruit storage rooms.

摘要

Inefficiency in fungicide treatment is one of the reasons for postharvest decay of fruits during the storage period. Postharvest treatment of fungicides using thermonebulisation fogging systems offers a promising means to minimize such postharvest decay. Moreover, this treatment method reduces the use of fungicides in the orchards, minimizes residues on the fruits and improves ecological and environmental sustainability. A three-dimensional computational fluid dynamics (CFD) model was developed to help optimize the application of the fungicide particles inside the fruit storage room. An Eulerian-Lagrangian multiphase flow model was used. The model takes into account two-way coupling with turbulent dispersion of the particles. The particle diameter distribution at the exit of the thermonebuliser was measured and used as an input to the model. The product loaded in vented bins was considered as a porous medium, where the loss coefficients to the three orthogonal directions were approximated using simulation of the flow through the vented boxes and stacks. The dynamic behaviour of the fan was also taken into account. The distribution of the fungicide particles was highly affected by the air flow distribution inside the room. Good agreement was found between measured and predicted results of deposition of fungicide particles.