化工学报2018，Vol.69Issue(2)：779-791,13.DOI:10.11949/j.issn.0438-1157.20170791
气相法聚乙烯工艺冷凝态操作模式的稳定性和动态行为
Stability and dynamic behaviors of gas-phase ethylene polymerization process under condensed mode operation
摘要
Abstract
Due to significant enhancement in heat removal capacity of recirculating gas and space-time yield of fluidized bed reactors, condensed mode operation has become most popular in gas-phase ethylene polymerization. A mathematical model for condensing mode operation of gas phase ethylene polymerization process was established, which included fluidized-bed reactor model, stage heat exchanger model, and control model of reactor temperature, pressure, and component partial pressure of recirculating gas. Process simulation was applied to obtain steady state solution when reactor temperature was controlled by close-loop, and dynamic behavior of the system under small perturbation was used to qualitatively analyze stability of ethylene polymerization when reactor temperature was controlled by open-loop and close-loop. Finally, stepwise response characteristics of ethylene polymerization close-loop system was studied under consideration of 1-hexene partial pressure and catalyst feed rate. Simulation results show that the steady state solutions are stable within the scope of studied conditions when reactor temperature is close-loop controlled, whereas the steady state solutions are divided into stable and unstable zone by bifurcation points when reactor temperature is open-loop controlled. The long and short period oscillations observed in stepwise response of reactor temperature to 1-hexene partial pressure reveal that ethylene polymerization system under condensed mode operation is a complex process with multiple coupling control loops.关键词
流化床/聚合/冷凝态/稳定性/动态建模Key words
fluidized-bed/polymerization/condensed mode/stability/dynamic modeling分类
化学化工引用本文复制引用
范小强,韩国栋,黄正梁,孙婧元,王靖岱,阳永荣,吴文清,谢磊..气相法聚乙烯工艺冷凝态操作模式的稳定性和动态行为[J].化工学报,2018,69(2):779-791,13.基金项目
国家自然科学基金项目(91434205) （91434205）
国家杰出青年基金项目(21525627) （21525627）
浙江省杰出青年科学基金项目(LR14B060001) （LR14B060001）
国家自然科学基金创新研究群体项目(61621002) （61621002）
浙江省自然科学青年基金项目(LQ18B060001) （LQ18B060001）
中央高校基本科研业务费专项资金项目(2017QNA4029).supported by the National Natural Science Foundation of China(91434205),the National Science Fund for Distinguished Young Scholars of China(21525627),the Young Scientists of the Natural Science Foundation of Zhejiang Province(LR14B060001),the Science Fund for Creative Research Groups of National Natural Science Foundation of China(61621002),the Natural Science Foundation of Zhejiang Province(LQ18B060001)and the Fundamental Research Funds for the Central Universities(2017QNA4029). （2017QNA4029）
