Numerical investigation on phosphine flow during fumigation of wheat in a Chinese horizontal warehouse

Abstract

The phosphine flow during fumigation of wheat in a Chinese horizontal warehouse is studied by computational fluid dynamics modeling. The Renormalization Group k-ε turbulence model is adopted to simulate the three-dimensional airflow field and the species transport model is used to calculate the species mixing. The phosphine concentrations in the warehouse with different leaky area positions during the fan-forced fumigation and the tablet fumigation are continuously predicted for 28.5 days. Also, the effects of the fumigation methods and the leaky area positions on the phosphine concentrations are discussed. The results reveal that the phosphine concentration in the tablet fumigation takes longer time to be uniform than that in the fan-forced fumigation. The maximum value of the phosphine concentration in the fan-forced fumigation is larger and appears earlier than that in the tablet fumigation. We also found that the fumigation methods have greater impact on the phosphine concentration than the leaky area positions in this study. And the impacts of the leaky area positions on the phosphine concentration could be further influenced by the fumigation methods.