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作者： Deming, Fang Ying, Li Baiyang, Lou Zhejiang University of Technology Institute of Process Equipment and Control Engineering MOE Key Laboratory of Mechanical Manufacture and Automation Hangzhou 310032 China

Microstructure, hardness and mechanical properties of the ICr5Mo steel tubes for the coking furnace at super temperature were investigated in this paper. It revealed that under super-temperature, oxidation corrosion for the furnace tubes was strengthened, wall thickness was evident thinner, pearlite in microstructure was spheroidised mostly, strength would be decreased and marked degradation in material occurred.

关键词： Coke fueled furnaces

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Simulation on sensing field of electromagnetic tomography technology 5

Simulation on sensing field of electromagnetic tomography te...

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5th World Congress in Industrial process Tomography

作者： Yixuan, X. Shu, Z. Feng, D. School of Electrical Engineering and Automation Tianjin University Tianjin China Institute of Biomedical Engineering Chinese Academy Medical Science Tianjin China Tianjin Key Laboratory of Process Measurement and Control Tianjin China

ISBN: (纸本)9780853163213

Electromagnetic Tomography (EMT) which combined electromagnetic theory and computerized tomography technology is one of the electrical tomography technologies. This technology can reconstruct the spatiotemporal distributions of the electrically conductive and magnetically permeable materials by detecting the boundary magnetic induction of the researching space. The sensor of the EMT system has advantages of non-invasive, non-contacting and non-hazardous. So it has many potential applications in industrial fields, such as processing, foreign body detection in food processing, geologic exploration and multi-phase flow measurement. This paper studies the sensing field of EMT using the finite element (FEM) simulation, and the magnetic induction distribution of the empty field with this excitation model has been acquired. The influence of objects with different permeability, conductivity, and positions on the excitation sensing field was analyzed. © 2007, International Society for Industrial process Tomography. All rights reserved.

关键词： Electric fields

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Assessment of fire damage to 321 stainless steel equipment in a chemical unit

Assessment of fire damage to 321 stainless steel equipment i...

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作者： Zhang, Wei Gao, Zengliang Zhang, Kangda Fang, Zheng Lu, Xiaoyan Bao, Weiguang Zhu, Guorong Zhejiang University of Technology Institute of Process Equipment and Control Engineering MOE Key Laboratory of Mechanical Manufacture and Automation Hangzhou China Ningbo Special Equipment Inspection and Testing Centre Ningbo China

In the present work, the mechanical properties of 321 stainless steel pressure equipments exposed to an accident fire in a chemical unit were investigated. The performance and microstructure of this material were described by chemical compositions analysis, tensile test, scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The experiment results showed that the mechanical properties of the material were degraded. The grains on the external surface of the fracture became coarse. These results indicated that serious damage to 321 stainless steel had been induced by extreme heat of the fire and this pressure vessel could not be used anymore.

关键词： Stainless steel

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Optimizing control of variable cycle time simulated moving beds 8th

Optimizing control of variable cycle time simulated moving b...

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8th IFAC Symposium on Dynamics and control of process Systems, 2007

作者： Grossmann, Cristian Amanullah, Mohammad Mazzotti, Marco Morbidelli, Massimo Morari, Manfred ETH Zurich Automatic Control Laboratory Physikstrasse 3 Zürich8092 Switzerland ETH Zurich Institute of Process Engineering Sonneggstrasse 3 Zürich8092 Switzerland ETH Zurich Institute for Chemical and Bio-Engineering Zürich8093 Switzerland

Simulated moving bed (SMB) is a cost-efficient chromatographic technique employed for difficult separation tasks. SMB processes exhibit complex dynamics, e.g., its hybrid nature due to the inlet/outlet port switches with nonlinearities and delays. The novel feature presented in this work is the extension of the 'cycle to cycle' control concept to make use as manipulated variables, of the four sectional flow rates and the switch time. Its effectiveness is demonstrated through two case studies;the startup of a SMB unit under plant-model mismatch and the rejection of a pump disturbance. © Copyright 2007 IFAC.

关键词： Disturbance rejection

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RECONFIGURATION OF DISCRETELY controlLED HYBRID SYSTEMS FOR CHANGING SPECIFICATIONS

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IFAC Proceedings Volumes 2007年第6期40卷 115-120页

作者： Thanh Ha Tran Olaf Stursberg Sebastian Engell Process Control Laboratory (BCI-AST) University of Dortmund 44221 Dortmund Germany Institute of Automatic Control Engineering (EI-LSR) Technical University of Munich 80290 Munich Germany

This paper proposes a method for discrete controller reconfiguration of hybrid systems with uncertain linear dynamics to account for abrupt events such as the occurrence of actuator faults or changes in the product specifications. Starting from a hybrid plant model and a controller modeled as a finite state automaton, a new controller is obtained considering an updated specification or changes in the plant structure by switching among logic controllers determined offline. The automatic computation of the controllers is carried out using a controller synthesis approach, which employs the concept of model abstraction and refinement. The method is applied to a multi-tank example.

关键词： Reconfiguration Synthesis Hybrid Systems Automata Logic control

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IDENTIFICATION METHODS FOR EXPERIMENTAL NONLINEAR MODELING OF COMBUSTION ENGINES

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IFAC Proceedings Volumes 2007年第10期40卷 351-357页

作者： Alexander Schreiber Rolf Isermann Darmstadt University of Technology Institute of Automatic Control Laboratory of Control Engineering and Process Automation Landgraf-Georg-Str. 4 D-64283 Darmstadt Germany Phone: +49 6151 16 2114 Fax: +49 6151 16 6114

The optimized control of combustion engines with regard to minimized fuel consumption and emissions requires nonlinear models. Because of an increase of control inputs, like fuel mass flow, injection angle, exhaust gas recirculation flow and several outputs like torque, nitrogen oxides (NOx), hydrocarbons (HC) and particulates the classical grid-based measurement techniques take too long time and do not include dynamics. Therefore different measurement strategies for the stationary and dynamic behavior are described, like Design of Experiments (DoE) and use of suitable neural networks and Pseudo-Random-Binary-Signals (PRBS). As the structure of the models is not precisely known a-priori, nonlinear identification methods in form of special versions of neural networks are good candidates. Therefore, it will be shown how with special amplitude-modulated pseudo random binary signals (APRBS), simultaneous excitation of several input signals, nonlinear multi-input multi-output models can be obtained in relatively short time.

关键词： Engine modeling nonlinear models neural networks dynamic modeling test generation

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Comparison of Event-Triggered and Cycle-Driven Models for Verifying SFC Programs

Comparison of Event-Triggered and Cycle-Driven Models for Ve...

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American control Conference (ACC)

作者： Sven Lohmann Olaf Stursberg Sebastian Engell Department of Biochemical-and Chemical Engineering Process Control Laboratory Universität Dortmund Dortmund Germany Department of Electrical Engineering Institute of Automatic Control Engineering Technical University Munich Munich Germany

As a complement to testing procedures, verification techniques as e.g. model checking have been proposed to analyze logic controllers specified as sequential function charts (SFC). For the success of these techniques suitable execution models of the SFC and of the programmable logic controllers (PLC) on which the SFC are implemented and operated in practice are crucial. This paper investigates and compares two different suggested transformation schemes for mapping SFC into timed automata (TA): an event-triggered and a cycle driven scheme. For the example of a laboratory experiment, the paper shows how the schemes lead to TA models of the controller which can, when complemented with appropriate plant models, be used for verifying properties as e.g. safety by employing the software tool UPPAAL. The event-triggered transformation scheme is found to lead to considerably smaller TA models and hence to be more suitable for verification purposes.

关键词： Programmable control automatic control Automata Laboratories Logic testing Logic programming IEC standards Computer languages Safety Cooling

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OPTIMIZING control OF VARIABLE CYCLE TIME SIMULATED MOVING BEDS

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IFAC Proceedings Volumes 2007年第5期40卷 201-206页

作者： Cristian Grossmann Mohammad Amanullah Marco Mazzotti Massimo Morbidelli Manfred Morari ETH Zurich Automatic Control Laboratory Physikstrasse 3 8092 Zürich Switzerland ETH Zurich Institute of Process Engineering Sonneggstrasse 3 8092 Zürich Switzerland ETH Zurich Institute for Chemical and Bio-Engineering 8093 Zürich Switzerland

Simulated moving bed (SMB) is a cost-efficient chromatographic technique employed for difficult separation tasks. SMB processes exhibit complex dynamics, e.g., its hybrid nature due to the inlet/outlet port switches with nonlinearities and delays. The novel feature presented in this work is the extension of the ‘cycle to cycle’ control concept to make use as manipulated variables, of the four sectional flow rates and the switch time. Its effectiveness is demonstrated through two case studies; the startup of a SMB unit under plant-model mismatch and the rejection of a pump disturbance.

关键词： Optimization Repetitive Model Predictive control automatic process control Simulated Moving Bed

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Fatigue crack growth behavior of 16MnR steel with the overload effect

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Cailiao Yanjiu Xuebao/Chinese Journal of Materials Research 2007年第SUPPL.期21卷 201-204页

作者： Wang, Xiaogui Gao, Zengliang Jiang, Yanyao Key Laboratory of Mechanical Manufacture and Automation Institute of Process Equipment and Control Engineering Zhejiang University of Technology Hangzhou 310032 China

Fatigue crack growth behavior of 16MnR steel was experimentally studied using compact specimens subjected to different R-ratios and overloading. The effects of different notch sizes ranging from very sharp to blunt were also investigated. The experimental results show that stable crack growth rate follows the Paris law and the R-ratio has an insignificant influence. A larger notch results in a larger deviation of the crack growth curve prior to stabilization. In addition, the influences of overload were studied particularly by applying one single overload after the crack growth rate reached the stable state. The results reveal that the crack growth rate was enhanced right after the application of the overload followed by a rapid decrease. And then the crack growth rate started to increase slowly and merged the stable crack growth curve eventually.

关键词： Steel

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Simulation of fatigue crack growth rate of 16MnR steel

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Cailiao Yanjiu Xuebao/Chinese Journal of Materials Research 2007年第SUPPL.期21卷 52-55页

作者： Chen, Jie Gao, Zengliang Zhuang, Lijian Key Laboratory of Mechanical Manufacture and Automation Institute of Process Equipment and Control Engineering Zhejiang University of Technology Hangzhou 310032 China

Fatigue crack growth rate for 16MnR steel was simulated based on a damage model, which is assessed with local stress and strain near the crack tip. The cyclic elastic-plastic stress-strain field near the crack tip is analyzed using the finite element method. Two sets of programs were developed to recall stress-strain responses and to calculate crack tip damage and crack growth rate. CT specimen fatigue crack growth experiments of 16MnR steel with two R-ratios were conducted at room temperature. Comparison of FE simulation and experiment results shows that the current simulation of crack growth based on the fatigue damage criterion is accordant with the results of the experiment.

关键词： Fatigue crack propagation

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