储粮熏蒸过程中磷化氢浓度的分布模型及验证研究

谷物在长期储存过程中会受到害虫的侵扰,通常需要使用诸如磷化氢等适量的熏蒸剂对仓储粮食进行熏蒸,从而杀死害虫,同时又要避免害虫产生耐药性和熏蒸剂的残留。本研究首先建立和验证了熏蒸剂(磷化氢)的对流扩散和吸附模型,并采用计算流体动力学方法对圆筒仓内谷物熏蒸过程中磷化氢质量浓度进行了数值预测,分析了熏蒸过程中磷化氢的质量浓度分布规律,得出熏蒸过程中磷化氢质量浓度分布是不均匀的,并且受到谷物吸附和不可逆化学反应的双重影响。

Study on the Model and Validation of Phosphine Fumigation in Stored Grains in Silos

Grains must be stored free from insect pests. All life stages of insects that infest stored grains may be killed by fumigating them with poisonous gases such as phosphine. In present paper, a mathematical model of the convective diffusion and sorption of fumigants in stored grains was developed so that it can be implemented by computational fluid dynamics (CFD). The model has been compared with published results and found to be in excellent agreement. It is shown that the fumigation is essentially non-uniform and that the spatial distribution of fumigant is affected by its adsorption and non-reversible chemical reaction on the grain kernels.