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A novel kind of multiple steady states characteristics in the dividing wall column

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Chinese Journal of Chemical Engineering 2019年第4期27卷 869-876页

作者： Erwei Song Zengxi Li Erqiang Wang School of Chemical Sciences University of Chinese Academy of Sciences

In this article, one kind of multiple steady states(MSS) phenomenon was investigated for a dividing wall column(DWC). The four-section model constructed in Aspen Plus was employed to simulate two DWC cases: mixture of n-hexane, n-heptane and n-octane;system of methanol, ethanol and n-propanol. It can be seen that there is a range of vapor split ratio in which multiple solutions of reflux ratio exist for fixed DWC configuration with the same feed and product streams. The width and the curve shapes of the MSS region, and the number of solutions change with the liquid split ratio. This MSS phenomenon was further explained using the component recovery around the prefractionator and the component recycling flow inside the DWC. This MSS phenomenon is helpful for DWC design by knowing the probable existence of multiple solutions in advance.

关键词： dividing wall column Multiple steady states Vapor split ratio Liquid split ratio Recycling flow

Simulated annealing-based optimal design of energy efficient ternary extractive dividing wall distillation process for separating benzene-isopropanol-water mixtures

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Chinese Journal of Chemical Engineering 2021年第5期34卷 203-210页

作者： Min Li Yue Cui Xiaojing Shi Zhishan Zhang Xiaoxiao Zhao Xiuyu Zhu Jun Gao College of Chemical and Biological Engineering Shandong University of Science and TechnologyQingdao 266590China

This article investigates the performances of different extractive distillation processes intensified with dividing-wall column for separating benzene-isopropanol-water ternary mixtures.All the processes with ethylene glycol as solvent are optimized with the minimal total annual cost(TAC)as target.In order to get the global optimal solution intelligently,an improved simulated annealing algorithm is adopted,which is programmed in MATLAB and linked to Aspen Plus.The results show that the extractive dividing wall column-solvent(EDWC-S)process consisting of an extractive dividing wall column and a solvent recovery column is the best scheme.It can reduce the TAC by 28.65%and CO_(2) emissions by 32.84% compared to the conventional triple-column extractive distillation process.

关键词： Extractive distillation dividing wall column Simulated annealing Optimization Benzene/isopropanol/water

Shortcut Method of Design and Energy-Saving Analysis of Sargent dividing Wall Column

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China Petroleum Processing & Petrochemical Technology 2018年第4期20卷 99-108页

作者： Fang Jing Cheng Xiaomin Li Xiaochun Xiang Ning Li Chunli School of Chemical Engineering Hebei University of Technology

The Sargent dividing wall column can implement four products separation sequences in one column based on Fully Thermally Coupled Distillation Column. The initial design parameters are required for the design optimization or dynamic control of the Sargent dividing wall column, and in order to make the rigorous simulation of the Sargent dividing wall column more conducive to convergence, a ten column model for complex Sargent column is established in this paper,and the shortcut design method of this model is proposed. The internal minimum vapor and liquid flow are obtained by the Underwood equations and the mass balance method and the V-min method. The separation for a 4-component shortcut mixture of pentane, hexane, heptane and octane was considered, while the initial values of design parameters and the ratio of vapor-liquid distribution of each column were calculated by using the shortcut design method of a ten column model. And by comparing the shortcut calculations with rigorous simulation results, the practicality and reliability of shortcut calculations were verified. The reason for energy saving was analyzed based on back-mixing. A virtual heat exchanger is proposed to make the Sargent dividing wall column more energy efficient.

关键词： Sargent dividing wall column shortcut design method energy saving virtual heat exchangers

Optimization of dividing Wall Column with Heat Transfer Process Across the Wall for Feed Properties Variation

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China Petroleum Processing & Petrochemical Technology 2019年第2期21卷 118-124页

作者： Hu Yuqi Li Chunli National-Local Joint Engineering Laboratory for Energy Conservation of Chemical Process Integration and Resources Utilization School of Chemical Engineering and TechnologyHebei University of Technology

This paper investigates the thermal-coupled effect across the wall and the optimal heat transfer region of the wall for enhancing the energy saving effect of dividing wall column (DWC), and also studies the effects of feed thermal condition (q) and middle component composition of feed (cB) on the heat transfer process, the optimal heat transfer region, and the maximum heat transfer quantity across the wall. The simulation results show that the maximum heat transfer quantity across the wall and the potential for energy saving increase with the increase of q, while with the limitation of temperature difference across the wall, the beneficial heat transfer effect between certain range of stages, which are involved in the optimal heat transfer region, cannot be realized completely for a specific value of q. Besides, compared with q, a changing cB does not change the degree of realizing the beneficial heat transfer effect, but can bring about the variation of liquid split ratio (RL) and vapor split ratio (Rv). Thus, for achieving a maximum energy-saving effect of DWC, different q and cB need to find its own corresponding suitable heat transfer process across the wall.

关键词： dividing wall column heat transfer process thermal-coupled effect feed properties

Simulation Optimization and Experimental Study of Cross-Wall Adiabatic dividing Wall Column Used to Separate Hexane-Heptane-Octane System

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China Petroleum Processing & Petrochemical Technology 2015年第1期17卷 108-116页

作者： Hu Yuqi Fang Jing Li Chunli School of Chemical Engineering and Technology Hebei University of Technology

Through separation of the hexane-heptane–octane system in a cross-wall adiabatic dividing wall column, the effects of feed position, side-draw position, liquid split ratio, vapor split ratio and their interactions on the energy consumption were analyzed by Aspen Plus under the constant product purity, and the response surface model for the energy consumption was regressed. Based on the restriction on the optimal operating zone, the comparison of different combinations of surrogate models and optimization methods showed that, the combination of the Kriging model and multi-island genetic algorithm(Kriging-MIGA) had better prediction ability than the combination of the response surface model and partial derivative method(RSM-PD), and RSM-PD had better optimization effect than Kriging-MIGA. With a self-made cross-wall adiabatic dividing wall column, the temperature at measuring points and the energy consumption were measured during experiments, the comparison between measured values and simulated ones demonstrated that the optimized values of variables searched by RSM-PD and Kriging-MIGA could be both used as the optimum technological conditions since the experimental reliability was ensured, with the optimum technological conditions shown below: The feed position is 6, the side-draw position is 7, the combinations of liquid split ratio and vapor split ratio are [0.14, 0.5] and [0.16, 0.52], respectively. RSM-PD and Kriging-MIGA can provide the appropriate optimization methods for the dividing wall column.

关键词： dividing wall column simulation optimization experimental validation

Endoscopic management of adolescent closed Cowper’s gland syringocele with holmium:YAG laser

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Asian Journal of Urology 2022年第3期9卷 340-342页

作者： Maria F.Becerra Nicholas Smith Abhishek Bhat Hemendra N.Shah Department of Urology Miller School of MedicineUniversity of MiamiMiamiFLUSA

Dear editor,The term“syringocele”originated from Greek words“syringo”meaning tube and“cele”meaning swelling and was first coined by Maizels et al.[1]in 1983 to represent a spectrum of dilatation of the normal Cowper’s gland duct.They classified syringocele into four morphological types:Simple,perforate,imperforate,and ruptured.Melquist et al.[2]simplified the classification by dividing syringocele into two groups:Closed and open syringocele.Usually diagnosed in the pediatric population,only 10 cases of adult syringocele were reported in literature till 2007[3].Endoscopic management is preferred in most symptomatic adolescent patients and various energy sources employed for endoscopic marsupialization include cold knife urethrotomy,electrocautery,or holmium laser[4,5].Use of holmium laser is reported only in three cases with maximum follow-up of up to 1 year[6e8].We herein report three additional cases of adolescent closed syringocele,provide detailed technique of laser marsupialization,and report its long-term postoperative outcome.The study was approved by the University of Miami Ethics Committee(study ID:20180511).

关键词： laser dividing swelling

FLOW CHARACTERISTICS IN dividing FLOW MANIFOLDS

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Journal of Shanghai Jiaotong university(Science) 1998年第1期3卷 64-69页

作者：王峻晔吴东棣

ＦＬＯＷＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＩＮＤＩＶＩＤＩＮＧＦＬＯＷＭＡＮＩＦＯＬＤＳＷａｎｇＪｕｎｙｅ（王峻晔）（Ｄｅｐｔ．ｏｆＥｎｅｒｇｙＥｎｇｉｎｅｅｒｉｎｇ，ＳｈａｎｇｈａｉＪｉａｏｔｏｎｇＵｎｉｖ．，Ｓｈａｎ... 详细信息

ＦＬＯＷＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＩＮＤＩＶＩＤＩＮＧＦＬＯＷＭＡＮＩＦＯＬＤＳＷａｎｇＪｕｎｙｅ（王峻晔）（Ｄｅｐｔ．ｏｆＥｎｅｒｇｙＥｎｇｉｎｅｅｒｉｎｇ，ＳｈａｎｇｈａｉＪｉａｏｔｏｎｇＵｎｉｖ．，Ｓｈａｎｇｈａｉ，Ｃｈｉｎａ）ＷｕＤｏｎｇ...

关键词：王峻 MANIFOLDS FLOW CHARACTERISTICS dividing

基于dividing Rectangles的多模态医学图像配准算法

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中国图象图形学报 2008年第4期13卷 749-755页

作者：张加万李谭孙济洲天津大学计算机科学与技术学院天津300072

为了准确、可靠地配准多模态医学图像,提出了一种基于互信息的全局优化配准算法。该算法首先提取出目标物体的外轮廓面,再用迭代最近点方法初步对齐图像;然后用确定性的全局优化方法—dividing Rectangles搜索归一化互信息的全局最优解... 详细信息

为了准确、可靠地配准多模态医学图像,提出了一种基于互信息的全局优化配准算法。该算法首先提取出目标物体的外轮廓面,再用迭代最近点方法初步对齐图像;然后用确定性的全局优化方法—dividing Rectangles搜索归一化互信息的全局最优解。该算法利用图像的特征信息,为dividing Rectangles方法提供了一个较好的初始配准位置,并充分利用了dividing Rectangles方法在小范围内的高效搜索能力。实验结果表明,对于3维人体脑部数据,该算法配准精度高、速度快,而且有效地避免了配准过程中出现的局部极值。

关键词：图像配准互信息 dividing Rectangles

Cellular senescence in musculoskeletal homeostasis,diseases,and regeneration

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Bone Research 2021年第4期9卷 444-455页

作者： Mei Wan Elise F.Gray-Gaillard Jennifer H.Elisseeff Department of Orthopaedic Surgery The Johns Hopkins University School of MedicineBaltimoreMDUSA Translational Tissue Engineering Center Wilmer Eye Institute and the Department of Biomedical EngineeringThe Johns Hopkins UniversityBaltimoreMDUSA

Emerging insights into cellular senescence highlight the relevance of senescence in musculoskeletal disorders,which represent the leading global cause of disability.Cellular senescence was initially described by Hayflick et al.in 1961 as an irreversible nondividing state in in vitro cell culture studies.We now know that cellular senescence can occur in vivo in response to various stressors as a heterogeneous and tissue-specific cell state with a secretome phenotype acquired after the initial growth arrest.In the past two decades,compelling evidence from preclinical models and human data show an accumulation of senescent cells in many components of the musculoskeletal system.Cellular senescence is therefore a defining feature of age-related musculoskeletal disorders,and targeted elimination of these cells has emerged recently as a promising therapeutic approach to ameliorate tissue damage and promote repair and regeneration of the skeleton and skeletal muscles.In this review,we summarize evidence of the role of senescent cells in the maintenance of bone homeostasis during childhood and their contribution to the pathogenesis of chronic musculoskeletal disorders,including osteoporosis,osteoarthritis,and sarcopenia.We highlight the diversity of the senescent cells in the microenvironment of bone,joint,and skeletal muscle tissue,as well as the mechanisms by which these senescent cells are involved in musculoskeletal diseases.In addition,we discuss how identifying and targeting senescent cells might positively affect pathologic progression and musculoskeletal system regeneration.

关键词： skeletal homeostasis dividing