乙烯精馏塔异常工况动态建模与分析

Dynamic Modeling and Analysis of Ethylene Column Abnormal Condition

影响乙烯精馏分离效果和产品质量的关键因素是精馏塔板效率,板效率受气相夹带、雾沫夹带及漏液等因素的影响。正常工况时,回流量越大塔顶冷凝量越大,出料板温度越低。当回流量继续增大超过一定范围时,会引起精馏塔漏液导致板效率下降,此时出料板温度不再下降反而升高,出现反转现象,精馏塔进入反转异常工况。针对这个问题,建立乙烯精馏塔异常工况动态数学模型,利用流程模拟软件进行模拟,获取乙烯精馏塔异常工况下出料温度和乙烯摩尔浓度随回流量变化的曲线,分析乙烯精馏塔异常工况特性。

Plate efficiency is the key factor which influences the rectification separation and product quality and is easily affected by vapor entrainment, entrainment and leakage. In normal condition, larger quantity of reflux brings about much more condensation at the column top and lower discharge plate temperature;when the quantity of reflux rises continuously and exceeds certain range, the distillation column may leak and result in the dropping of plate efficiency, and then, the discharge plate’s temperature begins to rise instead of falling and the distillation column comes into abnormal condition. Considering this, a dynamic mathematical model of ethylene column was built and through making use of process simulation software, the outlet temperature and ethylene molar concentration curve which changing with the quantity of reflux were obtained to analyze the feature of ethylene column’s abnormal condition.