Liquid Phase Distribution Characteristics Study In Trickle Bed Baesd On Porous Media Model

Trickle-Bed-Reactor is widely used in petroleum refining,petrochemical industry,and waste water purification processes to separate organic pollutants.The homogeneity of liquid phase distribution in the fixed bed of trickle bed catalyst is the main factor affecting the reaction efficiency and reliability,and is also the key index for optimizing the structure and operation parameters of trickle bed catalyst.In this paper,the fixed bed of catalyst in a trickle bed is equivalent to a porous medium with solid particle accumulation.The gas-liquid two-phase flow in the fixed bed of catalyst is numerically simulated by using the porous medium model.The liquid volume in the trickle bed with different catalyst particle diameter,structure of distributor and liquid flow rate is obtained.Fractional distribution nephogram.On this basis,the mean square deviation of liquid volume fraction is used as the evaluation index of liquid phase bias in each section of trickle bed to realize the quantitative evaluation of liquid phase distribution uniformity in trickle bed.The results show that when the particle diameter is small,the gap between particles is small,and the capillary force between particles is large,which promotes the dispersion of liquid and hinders the formation of local liquid flow path.Therefore,the degree of deviation is relatively low and the distribution of liquid is uniform.In addition,when the inlet flow rate is large,the flow velocity of liquid phase increases,the conflict between liquid and solid phase intensifies,and the radial dispersion velocity of liquid phase increases,thus improving the uniformity of liquid phase distribution.The effect of the structure of the distributor on the uniformity of liquid phase distribution is similar to that of the flow rate.Under the same conditions,the velocity of liquid phase increases when the inlet of a single hole is used,so the deflectivity is smaller and the distribution uniformity is better.In this paper,the effects of particle diameter,inlet flow rate and structure of distributor on liquid phase distribution in trickle bed reactor were studied by numerical simulation and experimental comparison,which can provide theoretical and data support for the optimization of structure and operation parameters of trickle bed reactor.