三套管连续换热式氨合成塔催化床的二维模型

The Two-Dimensional Mathematical Model for Synthetic Ammonia Catalytic Bed with Triple-tube and Internal Heat-Exchanger

本文建立了三套管连续换热式氨合成塔催化床的二维数学模型,用逸度表示反应速率,求得了床层内轴向和径向温度及浓度分布的数值解。模拟计算结果表明,由于冷却段催化床内插冷管,冷管内与床层内的温差较大,使床层的径向存在较大的温差。采用一维模型进行计算与实际情况存在一定的偏差,这一点在反应器的设计和催化剂的还原中是不容忽视的。

In the paper,a two dimensional model for synthetic Ammonia catalytic bed with triple-tube and heat exchangers was established. The reaction rate was expressed by using fugacities instead of partial pressure. The temperature and concentration profiles both in radial and axial directions were numerically calculated. The results showed that the temperature difference between the gas in the bed and gas in the cold tubes is remarkable. If one dimensional model was used in reactor simulation, a considerable deviation as compared with practical operation was observed. Attentions should be paid in ammonia reactor design and catalyst reduction operation when one-dimensional model was used.