大型工业化费托合成装置气液分离元件的CFD模拟

CFD simulation of gas-liquid separation component in large-scale industrial Fischer Tropsch synthesis plant

为提高费托合成装置关键组分重质烃的气液分离效率,建立了波纹板上气液两相流的三维CFD模型,研究了复杂结构波纹板内流体流动特性,分析了分离器内气相速度场、压力场分布以及雾滴的运动行为,考察了分离器结构参数对压降和分离效率的影响规律,并对两种不同结构的波纹板进行了工业化运行验证。模拟结果表明:带钩波纹板对改善费托合成气相回路气液分离的效果作用明显,分离效率及压降随钩片长度和钩片倾角的增大而增大,随叶片间距的增大而降低;工业化运行验证结果表明:带有钩片的分离元件不适用于费托合成浆态床工艺,与带钩波纹板相比,应用光滑波纹板后,重质烃分离量提高,分离器阻力降降低,循环气量增加,反应转化率增长,重质烃分离性能提高,产物馏程分割更为精细。

To improve the gas-liquid separation efficiency of heavy hydrocarbon,a key composition of the Fischer Tropsch synthesis plant,a three-dimensional CFD model of gas-liquid flow on the corrugated plate was established.The fluid flow characteristics inside a complex corrugated plate were studied,and the gas velocity field,pressure field distribution and droplet motion behavior inside the separator were analyzed.The influence of such parameters as separator structure and operating conditions on the pressure drop and separation efficiency was investigated.And industrial operation verification was carried out on corrugated plates with two different structures.The results showed that the complex structure corrugated plate had a significant effect on improving the gas-liquid separation in the Fischer Tropsch synthesis gas-phase loop.The separation efficiency and pressure drop increased with the increase of the hook piece length and inclination,and decreased with the increase of the blade spacing.The industrial operation verification results showed that the separation element with hook piece was not suitable for the Fischer Tropsch synthesis slurry bed process.Compared with the hook corrugated plate,after the application of smooth corrugated plate,the separation of heavy hydrocarbons was increased,the resistance drop of the separator was reduced,the circulating gas volume increased,the reaction conversion rate increased,the separation performance of heavy hydrocarbons was improved,and the product distillation range division was more refined.