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Journal of Thermal Science 2024年第2期33卷 408-421页

作者： SINGH Shailendra ANAND Abhishek SHUKLA Amritanshu SHARMA Atul Non-Conventional Energy Laboratory Rajiv Gandhi Institute of Petroleum TechnologyJais Amethi229304India

This study evaluates the effectiveness of phase change materials(PCMs) inside a storage tank of warm water for solar water heating(SWH) system through the theoretical simulation based on the experimental model of S.Canbazoglu et al.The model is explained by five fundamental equations for the calculation of various parameters like the effectiveness of PCMs,the mass of hot water,total heat content,and duration of charging.This study simulated eleven PCMs to analyze their effectiveness like Sodium hydrogen phosphate dodecahydrate(SHPD),OM 37,N-Eicosane(NE),Lauric acid(LA),Paraffin wax(PW),OM 48,Paraffin wax C_(20-33)(PW-C20-33),Sodium acetate trihydrate(SAT),Palmitic acid(PA),Myristic acid(MA),and Stearic acid(SA).Among all PCMs,the SHPD has found the highest value of effectiveness factor of 3.27.So,it is the most recommended PCM for the storage tank of the SWH system.The study also includes the melt fraction analysis of all enumerated PCMs corresponding to container materials of stainless steel,glass,aluminum mixed,tin,aluminum,and copper.This melt fraction analysis is performed by making a coding program in the FORTRAN programming language.Through the analysis,copper container material is found to have high melting rate for all PCMs so it is superior to other container materials.

关键词： theoretical model solar water heating system phase change material effectiveness factor melt fraction

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CALCULATION METHOD OF effectiveness factor FOR NON-LINEAR COMPLEX REACTION SYSTEM

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Journal of Energy Chemistry 1995年第1期 23-31页

作者： LI LinDepartment of Chemical Engineering, Tsinghua University Beijing 100084

A calculation procedure of the effectiveness factor for very complex multiple reaction system is developed by using the concept of continuous lumping. The calculation procedure proposed in this paper enables not only the reaction-diffusion equations to be solved as an initial value problem, but also the number of the nonlinear algebraic equation which have to be solved in each iterative step to be reduced considerably.

关键词： effectiveness factor complex reaction lumping

Diffusion and catalyst efficiency in hierarchical zeolite catalysts

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National Science Review 2020年第11期7卷 1726-1742页

作者： Peng Peng Xiong-Hou Gao Zi-Feng Yan Svetlana Mintova State Key Laboratory of Heavy Oil Processing China University of Petroleum Laboratory of Catalysis and Spectrochemistry (LCS) Normandy University National Graduate School of Engineering of Caen (ENSICAEN)University of Caen (UNICAEN) French National Center for Scientific Research (CNRS) Petrochemical Research Institute China National Petroleum Company

The preparation of hierarchical zeolites with reduced diffusion limitation and enhanced catalyst efficiency has become a vital focus in the field of zeolites and porous materials chemistry within the past decades. This review will focus on the diffusion and catalyst efficiency of hierarchical zeolites and industrial catalysts. The benefits of diffusion and catalyst efficiency at two levels of hierarchies (zeolitic component level and industrial catalyst level) from a chemical reaction engineering point of view will be analysed. At zeolitic component level, three types of mesopores based on the strategies applied toward enhancing the catalyst effectiveness factor are presented:(i)‘functional mesopores’(raising effective diffusivity);(ii)‘auxiliary mesopores’(decreasing diffusion length); and (iii)‘integrated mesopores’(a combination thereof). At industrial catalyst level, location and interconnectivity among the constitutive components are revealed.The hierarchical pore interconnectivity in multi-component zeolite based industrial catalysts is exemplified by fluid catalytic cracking and bi-functional hydroisomerization catalysts. The rational design of industrial zeolite catalysts at both hierarchical zeolitic component and catalyst body levels can be fully comprehended using the advanced in situ and/or operando spectroscopic, microscopic and diffraction techniques.

关键词： diffusion effectiveness factor pore connectivity hierarchical zeolite industrial catalyst advanced characterization

Adaptive fault-tolerant control based on boundary estimation for space robot under joint actuator faults and uncertain parameters

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Defence Technology（防务技术） 2019年第6期15卷 964-971页

作者： Rong-Hua Lei Li Chen School of Mechanical Engineering and Automation Fuzhou University

Since the joint actuator of the space robot executes the control instructions frequently in the harsh space environment,it is prone to the partial loss of control effectiveness(PLCE)fault.An adaptive fault-tolerant control algorithm is designed for a space robot system with the uncertain parameters and the PLCE actuator faults.The mathematical model of the system is established based on the Lagrange method,and the PLCE actuator fault is described as an effectiveness factor.The lower bound of the effectiveness factors and the upper bound of the uncertain parameters are estimated by an adaptive strategy,and the estimated value is fed back to the control algorithm.Compared with the traditional fault-tolerant algorithms,the proposed algorithm does not need to predetermine the lower bound of the effectiveness factor,hence it is more in line with the actual engineering application.It is proved that the algorithm can guarantee the stability of the closed-loop system based on the Lyapunov function method.The numerical simulation results show that the proposed algorithm can not only compensate for the uncertain parameters,but also can tolerate the PLCE actuator faults effectively,which verifies the effectiveness and superiority of the control scheme.

关键词： Space robot Actuator faults Uncertain parameters effectiveness factor Fault-tolerant control

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Effect of hierarchical ZSM-5zeolite crystal size on diffusion and catalytic performance of n-heptane cracking

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Frontiers of Chemical Science and Engineering 2018年第4期12卷 780-789页

作者： Shuman Xu Xiaoxiao Zhang Dangguo Cheng Fengqiu Chen Xiaohong Ren Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China School of Chemistry and Chemical Engineering Tianjin University of TechnologyTianjin 300384China State Key Laboratory of Fine Chemicals Dalian University of TechnologyDalian 116024China

Hierarchical ZSM-5 zeolite aggregates with different sizes of nanocrystals were synthesized using different amounts of the mesoporogen 3-aminopropyltriethoxysilane. The effect of the crystal size on the catalytic cracking of -heptane was investigated and the Thiele modulus and effectiveness factor were used to determine the reaction rate-limiting step. The crystal size affected the textual properties of the catalysts but not the acidic properties of the catalysts. The reaction rate was first order with respect to the -heptane concentration. Cracking over hierarchical zeolites with nanocrystal sizes larger than about 50 nm took place under transition-limiting conditions, whereas the reaction over hierarchical zeolites with nanocrystal sizes of 15 or 30 nm proceeded under reaction control conditions. Hierarchical ZSM-5 zeolite aggregates with smaller nanocrystals had better selectivity for light olefins which can be ascribed to the shorter diffusion path lengths and lower diffusion resistance in these catalysts. Furthermore, these catalysts had lower coking levels which can be attributed to the substantial number of mesopores which prevent the formation of coke precursors.

关键词： hierarchical ZSM-5 crystal size catalytic cracking Thiele modulus effectiveness factor

INTRAPARTICLE DIFFUSION EFFECTS IN FISCHER-TROPSCH SYNTHESIS Ⅱ.EFFECTS OF PARTICLE SIZE,TEMPERATURE AND PORE STRUCTURE

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Journal of Energy Chemistry 1996年第2期 107-115页

作者： SHEN Wen-Jie ZHOU Jing-Lai ZHANG Bi-Jiang (Institute of Coal Chemistry, The Chinese Academy of Sciences Taiyuan, Shanxi 030001)

The effectiveness tactors for a commercialized precipitated Fe/Cu/k catalyst used for the Fischer-Tropsch synthesis were found to decrcase with temperature and particlc size. the calculated results showed a good agreement with those obtained by kinetic investigations. The effects of catalyst pore structure on effectivcness factor were investigatcd as well, and it was revealed that the catalyst pore size has no significant cffect on efftectiveness factor tor the special case of Fischer-Tropsch synthesis under industrial operating conditions.

关键词： Fiseher-Tropsch synthesis operating temperature catalyst pore structure effectiveness factor precipitated Fe/Cu/K catalyst

INTRAPARTICLE DIFFUSION EFFECTS IN FISCHER-TROPSCH SYNTHESIS Ⅰ. MODELING OF DIFFUSION AND REACTION

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Journal of Energy Chemistry 1996年第1期 59-68页

作者： SHEN Wen-Jie ZHOU Jing-Lai ZHANG Bi-Jiang (Institute of Coal Chemistry, The Chinese Academy of Sciences Taiyuan, Shanxi 030001)

The FTS/WGS over precipitated Fe/Cu/K catalyst could be approximated as a single reaction that forms an average hydrocarbon product (CnHm) with water and carbon dioxide as its by-products. It is generally.assumed that the catalyst pores are filled with liquid wax produced during the synthesis. and thus, diffusivity in wax is inuch less than that in gas phase. Based on the intrinsic kinetics which accounts for water inhibition, as well as reaction diffusion model and single-reaction stoichiometry,effectiveness factors were calculated by assuming different sete of stoichiometric coefficients. Reasonable calculation procedure was established for the investigated catalyst. It was found that the effectiveness factors for gas/liquid system were about half of that for gas phase, which was expected as the diffusivities.

关键词： Fischer-Tropsch synthesis effectiveness factor precipitated Fe/Cu/K catalyst reaction diffusion model

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钢筋混凝土剪力墙塑性铰区受剪承载力分析

钢筋混凝土剪力墙塑性铰区受剪承载力分析

Mass Transfer Model for the Catalyst Capsule in Catalytic Distillation

第六届全国高强与高性能混凝土学术交流会

作者：文保军梁兴文侯莉娜西安建筑科技大土木工程学院西安建筑科技大土木工程学院

＜正＞1．引言钢筋混凝土剪力墙又称抗震墙,是一种有效的抗侧力构件,在高层建筑中得到广泛运用。剪力墙塑性铰区的剪切问题是剪力墙剪切问题中最重要的组成部分,是剪力墙延性设计的重要内容,同时也是尚未很好解决的问题之一。由于其影... 详细信息

＜正＞1．引言钢筋混凝土剪力墙又称抗震墙,是一种有效的抗侧力构件,在高层建筑中得到广泛运用。剪力墙塑性铰区的剪切问题是剪力墙剪切问题中最重要的组成部分,是剪力墙延性设计的重要内容,同时也是尚未很好解决的问题之一。由于其影响因素众多、受力复杂,国内外对此问题研究不够深入,故其受剪机理尚不十分清楚。在我国的混凝土结构设计规范

关键词： shear wall yield hinge regions shear capacity truss and strut actions effectiveness factor

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Mass Transfer Model for the Catalyst Capsule in Catalytic Di...

Study of internal diffusion effect on selective hydrodesulfurization of FCC gasoline

Third Joint China/USA Chemical Engineering Conference

作者： Wu yanxiang Wang liangen Zhao Zhishan (Department of chem. Eng. Fuzhou University Fuzhou 350002 China) Tan Tianen (Department of chem. Eng. Zhejiang University Hangzhou 310027 China)

＜正＞The mass transfer in the catalyst capsule is analysed and a twodimensional model was put forward. By solving the reaction-diffusion equation, the reactant concentration distribution in the catalyst capsule and the effectiveness factor expression are obtained, it is indicated that the catalyst efficiency is influenced by axial liquid flow, diffusion and wetting of catalyst beads.

关键词： mass transfer model effectiveness factor catalyst capsule

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Study of internal diffusion effect on selective hydrodesulfu...