Performance Study of a Thermally Double Coupled Multi-Tubular Reactor by Considering the Effect of Flow Type Patterns

2016 ◽  
Vol 14 (1) ◽  
pp. 63-78 ◽  
Author(s):  
Mohsen Abbasi ◽  
Mehdi Farniaei ◽  
Sedigheh Kabiri ◽  
Mohammad Reza Rahimpour ◽  
Saeid Abbasi
Keyword(s):  
Current Flow ◽  
Tubular Reactor ◽  
Current Mode ◽  
Superior Performance ◽  
Performance Study ◽  
Reversed Flow ◽  
One Dimensional ◽  
Production Of Hydrogen ◽  
Simulation Results ◽  
Counter Current

AbstractIn this study, a steady-state heterogeneous one-dimensional model predicts the performance of a thermally double coupled auto-thermal multi-tubular reactor for simultaneous production of hydrogen, benzene, methanol and dimethyether (DME) in an economical approach for both co- and counter- current modes of operation. Reversed flow of cyclohexane has been considered for the counter-current flow regime. The simulation results for co- and counter-current modes have been investigated and compared with corresponding predictions for conventional methanol reactor and traditional coupled methanol reactor. In addition, various operating parameters along the reactor have been studied. The simulation results present that methanol yield in co- and counter- current modes are reached to 0.3735 and 0.3363 in a thermally double coupled reactor, respectively. Also, results for counter-current mode show a superior performance in hydrogen and benzene production. Finally, the results of simulation illustrate that the coupling of these reactions could be beneficial.

Modeling and Comparison a Thermally Coupled Reactor of Methane Tri – Reforming and Dehydrogenation of Cyclohexane Reactions for Syngas Production in Both Co- & Counter-Current Modes

2018 ◽  
Vol 17 (1) ◽  
Author(s):  
E. Dehghanfard ◽  
Z. Arab Aboosadi
Keyword(s):  
Fixed Bed ◽  
Current Mode ◽  
Superior Performance ◽  
Hydrogen Yield ◽  
The Novel ◽  
One Dimensional ◽  
Syngas Production ◽  
Dehydrogenation Of Cyclohexane ◽  
Double Pipe ◽  
Counter Current

Abstract The aim of this work is a comparison of different inlets (Co- and Counter-current modes) to feed a thermally coupled reactor (TCR) in producing syngas as a valuable chemical. The novel thermally coupled reactor has been designed as a double pipe reactor where tri-reforming of methane for syngas production has been considered in the exothermic side of fixed bed plug reactor, and dehydrogenation of cyclohexane reaction occur in the endothermic side. The heat generated in the exothermic part by the walls of the tube side is transferred to the endothermic section. A steady-state homogeneous one-dimensional model predicts the performance of this reactor for simultaneous production of synthesis gas and benzene in an economical approach for both co- and counter-current modes of operation. The reversed flow of cyclohexane has been considered for the counter-current flow regime. The simulation results of co- and counter-current modes of TCR and also an optimized tri-reforming of methane (OTRM) single reactor are investigated and compared with each other. The results showed that methane conversion, hydrogen yield and ${H_2}/Co$ ratio in the exothermic side of TCR reached to 91.1 %, 1.82 and 2.1 in co-current mode and 87.8 %, 1.77 and 2.3 in counter-current mode, respectively. Additionally, the results showed that cyclohexane conversion at the endothermic side of the reactor in co- and counter-current modes achieved to 98.6 % and 99.9 %, respectively. So, the results for counter-current mode showed superior performance in hydrogen and benzene production in the endothermic side of TCR. Also, Changes in various operating parameters during the reactor have been studied.

scholarly journals Injection-rolling nozzle in an imprint system with continuous injection direct rolling for ultra-thin microstructure guide light plate

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110112
Author(s):  
Yan Lou ◽  
Kewei Chen ◽  
Xiangwei Zhou ◽  
Yanfeng Feng
Keyword(s):  
Flow Velocity ◽  
Superior Performance ◽  
Light Transmittance ◽  
Velocity Difference ◽  
Orthogonal Experiments ◽  
Width Direction ◽  
Direct Rolling ◽  
Simulation Results ◽  
Continuous Injection ◽  
Better Than

A novel Injection-rolling Nozzle (IRN) in an imprint system with continuous injection direct rolling (CIDR) for ultra-thin microstructure polymer guide light plates was developed to achieve uniform flow velocity and temperature at the width direction of the cavity exit. A novel IRN cavity was designed. There are eight of feature parameters of cavity were optimized by orthogonal experiments and numerical simulation. Results show that the flow velocity at the width direction of the IRN outlet can reach uniformity, which is far better than that of traditional cavity. The smallest flow velocity difference and temperature difference was 0.6 mm/s and 0.24 K, respectively. The superior performance of the IRN was verified through a CIDR experiment. Several 0.35-mm thick, 340-mm wide, and 10-m long microstructural Polymethyl Methacrylate (PMMA) guide light plates were manufactured. The average filling rates of the microgrooves with the aspect ratio 1:3 reached above 93%. The average light transmittance is 88%.

scholarly journals Zero Watermarking Algorithm for Vector Geographic Data Based on the Number of Neighboring Features

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 208
Author(s):  
Qifei Zhou ◽  
Changqing Zhu ◽  
Na Ren ◽  
Weitong Chen ◽  
Weiteng Gong
Keyword(s):  
Copyright Protection ◽  
Second Order ◽  
Superior Performance ◽  
Statistical Characteristics ◽  
First Order ◽  
Geographic Data ◽  
Simulation Results ◽  
Topological Characteristics ◽  
Zero Watermarking ◽  
Critical Challenge

Zero watermarking is an important part of copyright protection of vector geographic data. However, how to improve the robustness of zero watermarking is still a critical challenge, especially in resisting attacks with significant distortion. We proposed a zero watermarking method for vector geographic data based on the number of neighboring features. The method makes full use of spatial characteristics of vector geographic data, including topological characteristics and statistical characteristics. First, the number of first-order neighboring features (NFNF) and the number of second-order neighboring features (NSNF) of every feature in vector geographic data are counted. Then, the watermark bit is determined by the NFNF value, and the watermark index is determined by the NSNF value. Finally, combine the watermark bits and the watermark indices to construct a watermark. Experiments verify the theoretical achievements and good robustness of this method. Simulation results also demonstrate that the normalized coefficient of the method is always kept at 1.00 under the attacks that distort data significantly, which has the superior performance in comparison to other methods.

Model development and control of an auto-refrigerated polystyrene polymerization reactor

2021 ◽  
pp. 014233122110251
Author(s):  
Reyhane Mokhtarname ◽  
Ali Akbar Safavi ◽  
Leonhard Urbas ◽  
Fabienne Salimi ◽  
Mohammad M Zerafat ◽  
...  
Keyword(s):  
Temperature Control ◽  
Model Development ◽  
Heat Removal ◽  
Superior Performance ◽  
Polymerization Process ◽  
Vacuum System ◽  
Control Scheme ◽  
Simulation Results ◽  
And Control ◽  
Operating Plant

Dynamic model development and control of an existing operating industrial continuous bulk free radical styrene polymerization process are carried out to evaluate the performance of auto-refrigerated CSTRs (continuous stirred tank reactors). One of the most difficult tasks in polymerization processes is to control the high viscosity reactor contents and heat removal. In this study, temperature control of an auto-refrigerated CSTR is carried out using an alternative control scheme which makes use of a vacuum system connected to the condenser and has not been addressed in the literature (i.e. to the best of our knowledge). The developed model is then verified using some experimental data of the real operating plant. To show the heat removal potential of this control scheme, a common control strategy used in some previous studies is also simulated. Simulation results show a faster dynamics and superior performance of the first control scheme which is already implemented in our operating plant. Besides, a nonlinear model predictive control (NMPC) is developed for the polymerization process under study to provide a better temperature control while satisfying the input/output and the heat exchanger capacity constraints on the heat removal. Then, a comparison has been also made with the conventional proportional-integral (PI) controller utilizing some common tuning rules. Some robustness and stability analyses of the control schemes investigated are also provided through some simulations. Simulation results clearly show the superiority of the NMPC strategy from all aspects.

scholarly journals Compressive Sensing Based Sampling and Reconstruction for Wireless Sensor Array Network

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Ming Yin ◽  
Kai Yu ◽  
Zhi Wang
Keyword(s):  
Compressive Sensing ◽  
Sensor Array ◽  
Superior Performance ◽  
Wireless Sensor ◽  
Prototype System ◽  
Reconstruction Method ◽  
Compressed Sampling ◽  
Data Volume ◽  
Simulation Results ◽  
Sparsity Structure

For low-power wireless systems, transmission data volume is a key property, which influences the energy cost and time delay of transmission. In this paper, we introduce compressive sensing to propose a compressed sampling and collaborative reconstruction framework, which enables real-time direction of arrival estimation for wireless sensor array network. In sampling part, random compressed sampling and 1-bit sampling are utilized to reduce sample data volume while making little extra requirement for hardware. In reconstruction part, collaborative reconstruction method is proposed by exploiting similar sparsity structure of acoustic signal from nodes in the same array. Simulation results show that proposed framework can reach similar performances as conventional DoA methods while requiring less than 15% of transmission bandwidth. Also the proposed framework is compared with some data compression algorithms. While simulation results show framework’s superior performance, field experiment data from a prototype system is presented to validate the results.

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