摘要
焦炭塔是石油化工中常见的重油轻质化利用的反应器,由于内部温度高,实验监测困难,加之内部流动、传热、反应过程复杂,塔内温度场分布不均匀,给反应过程的精准调控带来巨大挑战。本研究根据焦炭塔内气相、液相以及焦炭的分布规律,采用连续介质模型(欧拉方程)模拟气体、液相石油以及焦炭运动,并耦合三相间的传热模型和七集总反应动力学模型,建立了焦炭塔的多尺度计算模型。通过与釜式反应器焦化实验对比,验证了模型的准确性。进一步模拟了焦炭塔中试装置的进料和中间相沥青质成焦过程,研究了不同操作温度下焦炭塔内的流场、温度场分布以及产物的变化规律,从而为精准调控焦炭塔生焦过程提供依据。
Coke drum is the conventional reactor for processing heavy oil into light chemicals in petrochemical industry.Because of the high operation temperature within the reactor,experimental monitoring is particularly difficult.The complex processes within the coke drum involve the fluid flow,heat transfer and reaction,and the heterogeneous temperature distribution make it challenging for precise regulation.This study considers the distribution of gas phase,liquid oil,and solid coke in the reactor and adopts continuous medium model(Eulerian model)to simulate the motion of three phases and couples the heat transfer model and seven-lumped reaction kinetics model,so as to establish a multiscale model for the coke drum reactor.The accuracy of this model is validated by comparing the simulation and experiment results in the kettle reactor.Furthermore,the feeding process and the coke growth from mesoasphaltene are modelled,and the flow field,temperature distribution,and coke generation rate under different operating conditions are studied.The results show that the coking process and the heterogeneous distribution of multi-physical field in the reactor are greatly influenced by temperature.The mass fraction and growth rate of coke and gas products increase a lot at high temperature.In order to regulate the distribution and growth rate of the coke product,the mesoasphaltene,which is the precursor product of the coke,is generated with temperatures no more than 450℃at feeding stage,so that the coke growth rate is restricted.Afterwards,the temperature is improved by heating reactor walls and injecting hightemperature steam,in which the reaction rate of mesoasphaltene towards coke product increases and the uniform distribution of coke can be obtained.This study provides an important case for regulating distribution and growth of coke product by coordinating the temperature field and flow characteristics within the coke drum.
作者
陈渤燕
曹玉亭
张勇
孙国刚
刘银东
王路海
Boyan CHEN;Yuting CAO;Yong ZHANG;Guogang SUN;Yindong LIU;Luhai WANG(Institute of Mechanical and Transportation Engineering,China University of Petroleum(Beijing),Beijing 102249,China;State Key Laboratory of Multiphase Complex Systems,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China;Petrochemical Research Institute,China National Petroleum Corporation,Beijing 102249,China)
出处
《过程工程学报》
CAS
CSCD
北大核心
2024年第4期414-424,共11页
The Chinese Journal of Process Engineering
基金
中国石油科技管理部常规项目(编号:2021DJ5908)
国家自然科学基金资助项目(编号:22008239)。
关键词
焦炭塔
欧拉模型
中间相沥青质
温度场调控
焦炭分布
coke drum
Eulerian model
mesoasphaltene
temperature regulation
coke distribution
