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Combining reinforcement learning with mathematical programming:An approach for optimal design of heat exchanger networks

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Chinese Journal of Chemical Engineering 2024年第5期69卷 63-71页

作者： Hui Tan Xiaodong Hong Zuwei Liao Jingyuan Sun Yao yang Jingdai Wang yongrong yang State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China ZJU-Hangzhou Global Scientific and Technological Innovation Center Hangzhou 311215China

Heat integration is important for energy-saving in the process *** is linked to the persistently challenging task of optimal design of heat exchanger networks(HEN).Due to the inherent highly nonconvex nonlinear and combinatorial nature of the HEN problem,it is not easy to find solutions of high quality for large-scale *** reinforcement learning(RL)method,which learns strategies through ongoing exploration and exploitation,reveals advantages in such ***,due to the complexity of the HEN design problem,the RL method for HEN should be dedicated and designed.A hybrid strategy combining RL with mathematical programming is proposed to take better advantage of both *** insightful state representation of the HEN structure as well as a customized reward function is introduced.A Q-learning algorithm is applied to update the HEN structure using theε-greedy *** results are obtained from three literature cases of different scales.

关键词： Heat exchanger network Reinforcement learning Mathematical programming Process design

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镍催化可控/活性自由基聚合反应研究进展

化工学报 2024年第4期75卷 1105-1117页

作者：程骁恺历伟王靖岱阳永荣浙江大学宁波科创中心浙江宁波325000 浙江大学化学工程与生物工程学院浙江杭州310058

可控/活性自由基聚合是近年来发展的温和、聚合反应进程可控、分子结构可设计性强的自由基聚合反应技术,其核心在于活性自由基中间体与催化剂/链转移剂的可逆活化/失活过程,常用于极性单体聚合制备结构多样的有机高分子材料。镍催化剂... 详细信息

可控/活性自由基聚合是近年来发展的温和、聚合反应进程可控、分子结构可设计性强的自由基聚合反应技术,其核心在于活性自由基中间体与催化剂/链转移剂的可逆活化/失活过程,常用于极性单体聚合制备结构多样的有机高分子材料。镍催化剂具有多变的中心金属价态及多样的聚合反应机理,在可控/活性自由基聚合领域存在独特的优势。对近年来原子转移自由基聚合(ATRP)和有机金属控制的活性自由基聚合(OMRP)中的镍催化剂结构、聚合反应机理、反应行为和产物结构特征进行了综述,并对镍催化的可控/活性自由基聚合未来发展方向和应用前景进行了展望。

关键词：镍催化剂自由基聚合可控/活性自由基聚合

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基于自适应变步长同伦法的循环流程收敛算法

化工学报 2024年第7期75卷 2604-2612页

作者：李洪瑞黄纯西洪小东廖祖维王靖岱阳永荣化学工程联合国家重点实验室浙江大学浙江杭州310027 功能材料智能设计与制造浙江省工程研究中心浙江大学杭州国际科创中心浙江杭州311215

包含循环流股的流程模拟面临初值难给定和传统算法收敛困难的问题。针对该问题提出了自适应变步长同伦算法,通过自适应调整同伦参数步长处理中间过程收敛失败的情形,提高收敛效率,并采用回溯线搜索法将迭代变量限制在定义域内,以提升算... 详细信息

包含循环流股的流程模拟面临初值难给定和传统算法收敛困难的问题。针对该问题提出了自适应变步长同伦算法,通过自适应调整同伦参数步长处理中间过程收敛失败的情形,提高收敛效率,并采用回溯线搜索法将迭代变量限制在定义域内,以提升算法的鲁棒性。构建了基于直接迭代法、Wegstein法、Broyden法和牛顿法的同伦算法,分析了同伦参数和辅助函数的影响。以淤浆法工艺生产高密度聚乙烯作为案例,模拟结果表明同伦算法可以提高模型在不同工况下的收敛性。商业流程模型软件Aspen Plus内置的求解器最高仅在21%测试工况下可以获得可行解,而同伦算法收敛案例占比可达88%。

关键词：过程系统算法化学过程模拟同伦法

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基于人工神经网络的工质基础物性预测

石油炼制与化工 2024年第1期55卷 180-188页

作者：林美金董轩洪小东廖祖维孙婧元杨遥王靖岱阳永荣浙江大学化学工程与生物工程学院杭州310030 浙江大学杭州国际科创中心

烃类及卤代烃是制冷及余热发电等热力学循环系统潜在的理想工质,但其数量繁多且多数物性参数未知,建立准确的物性预测模型对新型工质的开发至关重要。从多个公开数据库中收集了2500多种烃类及卤代烃分子(含C,H,F,Cl)的基础物性参数,包... 详细信息

烃类及卤代烃是制冷及余热发电等热力学循环系统潜在的理想工质,但其数量繁多且多数物性参数未知,建立准确的物性预测模型对新型工质的开发至关重要。从多个公开数据库中收集了2500多种烃类及卤代烃分子(含C,H,F,Cl)的基础物性参数,包括正常沸点(T_(b))、临界温度(T_(c))、临界压力(p_(c))、偏心因子(ω),构建了一个工质物性数据库;进一步,通过改进基团贡献-人工神经网络(GC-ANN)的方法,模型的输入参数除基团频率外,还加入相对分子质量、T_(b)、约化维纳指数,建立了预测烃类及卤代烃分子T_(b),T_(c),p_(c),ω的神经网络模型,所开发模型的预测误差小于传统的GC-ANN的误差。

关键词：新型工质物性预测基团贡献法 BP神经网络

Hydrodynamic Instability Analysis of the Axial Flow Pump in an Ethylene Polymerization Loop Reactor

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China Petroleum Processing & Petrochemical Technology 2022年第1期24卷 135-148页

作者： Lu Jin yang Yao Sun Jingyuan Huang Zhengliang yang yongrong Wang Jingdai Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310058 State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310058

The hydrodynamic instability of the axial flow pump in a loop reactor has long been a troubling issue to be solved in the polyethylene industry due to the lack of a better mechanismic ***,the instability of an axial flow pump can be reflected by the fluctuation of the pump *** this study,the transient computational fluid dynamics(CFD)simulation is adopted to study the hydrodynamic instability of the axial flow pump used in an ethylene polymerization loop *** results show that the pump head under single liquid phase nearly remains constant while the pump head under slurry phase fluctuates due to the variation of solid volume fraction distribution in the ***,under the combined effect of the maximum solid volume fraction difference in the pump and the turbulence intensity of the liquid phase,the fluctuation of the pump head under slurry phase increases when the solid volume fraction in the loop reactor increases from 0.10 to 0.29,and the fluctuation decreases,when the solid volume fraction increases from 0.29 to ***,there is a negative correlation between the pump head and the solid volume fraction in the pump;with the increase of solid volume fraction in the loop reactor,and the correlation coefficient increases as ***,a‘spiral particulate band’phenomenon is formed in the ascending leg caused by three mechanisms,viz.:the segregation of particles in all bends,the dispersion of particles by the secondary flow in the ascending leg,and the rotational movement of particles in the pump.

关键词： axial flow pump loop reactor CFD hydrodynamic instability polyethylene

Scale-up and thermal stability analysis of fluidized bed reactors for ethylene polymerization

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Chinese Journal of Chemical Engineering 2023年第10期62卷 281-290页

作者： Xiaoqiang Fan Jingyuan Sun Jingdai Wang Zhengliang Huang Zuwei Liao Guodong Han yongrong yang Ningbo Research Institute Zhejiang UniversityNingbo 315100China State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology Hangzhou 310027China Sinopec Tianjin Company Tianjin 300271China

A set of hydrodynamic similarity laws is applied to the scale-up of ethylene polymerization fluidized bed reactors(FBRs)under the condensed mode *** thermal stability of open-loop controlled FBRs is investigated by the homotopy continuation *** the Hopf bifurcation point is selected as an index of the thermal stability *** simulation results show the similarity in state variables,operation parameters,the space-time yield(STY),and the thermal stability of FBRs with different ***,the thermal stability behaviors and similarity of the closed-loop controlled FBRs with different scales are *** observed similar trend of Hopf bifurcation curves reveals the similarity in the thermal stability of closed-loop controlled FBRs with different scaling *** general,the results of the thermal stability similarity confirm that the hydrodynamics scaling laws proposed in the work are applicable to the scale-up of FBRs under the condensed mode operation.

关键词： Stability Scale-up Polymerization Bifurcation theory Fluidized bed

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微化工精馏分离技术研究进展

化工学报 2024年第1期75卷 47-59页

作者：郑雨婷方冠东张梦波张浩淼王靖岱阳永荣化学工程联合国家重点实验室浙江大学化学工程与生物工程学院浙江杭州310058

综述了以微尺度结构为核心的微化工精馏分离技术的研究进展。基于传统精馏存在的节能技术落后、设备效能低以及难分离近沸点物系等问题,介绍了易于实现过程强化的微精馏分离技术,包括常规微蒸馏/微精馏、毛细管力微精馏、离心力微精馏... 详细信息

综述了以微尺度结构为核心的微化工精馏分离技术的研究进展。基于传统精馏存在的节能技术落后、设备效能低以及难分离近沸点物系等问题,介绍了易于实现过程强化的微精馏分离技术,包括常规微蒸馏/微精馏、毛细管力微精馏、离心力微精馏、真空微精馏、重力微精馏等多种方法,在流动化学应用中将起到重要作用。在微尺度条件下,相间传质传热效率随传质距离的缩短显著增强,同时精馏分离流程具有安全可控、连续高效的特点。微尺度精馏分离技术具有独特优势,为化工精馏实现环保、降耗的目标提供了解决方案,也为流动化学合成系统的开发与完善提供了可能。

关键词：蒸馏精馏微通道分离微化工技术流动化学

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Acidity Modification of ZSM-5 for Methane Conversion in Co-feeding Method with MTA Reaction

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Chemical Research in Chinese Universities 2022年第4期38卷 1012-1017页

作者： YU Yue XI Zhixiang ZHOU Bingjie JIANG Binbo LIAO Zuwei yang Yao WANG Jingdai HUANG Zhengliang SUN Jingyuan yang yongrong Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology College of Chemical and Biological EngineeringZhejiang UniversityHangzhou310027P.R.China

Acidity plays a vital role in methane conversion by co-feeding method,which is one of the best strategies to improve the utilization and gentle the reaction conditions of *** this work,Zn,Ni,Mo,La,Ga,Fe and Co-impregnated ZSM-5 zeolites have been prepared with the same substitutions to variate the acidities and tested in co-aromatization of methanol with *** is demonstrated that the new medium-strong acid sites formed by metal and strong acid sites are the key role to activate methane in ***-modified ZSM-5 catalyst is preferred to exhibit the best methane conversion of 12%,whose aromatic selectivity increases from 27.2%to 52.2%compared with that of ***,the addition of methane further improves the production of high-valued aromatics compared with methanol to aromatics(MTA)reaction.

关键词： Methane Methanol to aromatics(MTA) Co-reaction Acid site

Particle agglomeration and inhibition method in the fl uidized pyrolysis reaction of waste resin

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