固定床加氢反应器气相分配器数值模拟研究及防腐

Numerical simulation and corrosion protection of gas phase distributor in fixed bed hydrogenation reactor

轻质油品固定床加氢反应器内介质基本为气相,而气相物流流动性大,气体偏流和气体端效应会大大降低设备效率,使产品质量下降,并且传统的泡帽式分配器在高温、临氢环境下容易受到高温氢腐蚀,出现锈蚀、坑蚀、开裂等现象导致分配器失效,因此开发了新型气相分配器。为了深入了解分配器内部流体流动状态,采用CFX软件对单个新型气相分配器的流体力学性能进行模拟研究。模拟研究结果表明:新型气相分配器的扩散面积广,不存在中心汇流现象,气相均布性能好;数值模拟结果与冷模试验结果的出口截面平均流速和压力降的相对误差均小于20%,数值模拟与冷模试验的结果较吻合,证明了新型气相分配器在轻质油品气相加氢过程的优越性。

The reactants were basically gas phase in the light oil fixed-bed hydrogenation reactor;because the fluidity of gas phase was flexible,gas flow deflection and gas end effect greatly reduced equipment efficiency and product quality.The tradition-al bubble cap distributor was prone to high temperature hydrogen attack under high temperature and hydrogen environment,resul-ting in corrosion,pitting,cracking,etc.,which led to the failure of the distributor,so a new gas phase distributor was devel-oped.In order to investigate the fluid flow state inside the distributor,hydrodynamic performance of a single new type gas-phase distributor was simulated by CFX.The research demonstrated the new distributor had wide diffusion area,no central confluence phenomenon,and good distribution performance;the relative errors of the average flow velocity and pressure drop at the outlet section between the numerical simulation data and the cold model test data were both less than 20%,thus the two results were in good agreement,which proved the superiority of the new type distributor in the gas phase hydrogenation process of light oil prod-ucts.Moreover,the failure causes of the distributor were analyzed,and the characteristics of several anti-corrosion methods for distributors were compared.In industrial applications,factors such as anti-corrosion requirement,material of equipment,cost,construction difficulty and maintenance cycle should be considered comprehensively.