减压塔模拟计算方法的改进

提出一种改进的减压塔(压力敏感过程)模拟计算方法,该方法考虑了塔内流体负荷变化对减压塔各段填料和内件压力降的影响,将填料压力降和内件压力降关联式嵌入模拟软件中,能够准确地反映塔内各段的压力以及相关的气液平衡、气液负荷和物性。填料压力降采用对应的关联式,内件采用经CFD模拟得到的关联式。采用改进方法考察了减压塔进料量和汽提蒸汽量变化对闪蒸段气化率、平衡常数及气液物性的影响。结果表明,流体负荷变化对减压塔内的压力、平衡关系及物性有较大影响,对于减压塔及其他压力敏感过程时应采用该模拟方法。

Improvement of simulation calculation method for vacuum tower

An improved simulation calculation method for vacuum tower is presented.In this method,the impact of variations of fluid load in the tower on the pressure drop of packings and internals is considered,and correlation equations of packings’ pressure drop and internals’ pressure drop are embedded in simulation software,which can accurately reflect the pressure in different zones of tower,relative gas/liquid phase balance,gas/liquid phase load and physical properties.Corresponding correlation equation is applied for packings’ pressure drop while correlation equation from CFD simulation is applied for internals’ pressure drop.The improved method is adopted to study the impact of variations of feed rate of vacuum tower and flowrate of stripping steam on vaporization rate of flash zone,balance constant and physical properties of gas and liquid.The results show that the variation of fluid loads has a greater impact on the pressure in the vacuum tower,balance relation and physical properties.This simulation method should be used in the engineering design.