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Records with Keyword: Simulation
Showing records 1 to 25 of 41. [First] Page: 1 2 Last
Dynamic Modeling and Simulation of Basic Oxygen Furnace (BOF) Operation
Daniela Dering, Christopher Swartz, Neslihan Dogan
June 23, 2020 (v1)
Keywords: basic oxygen furnace, dynamic model, Simulation
Basic oxygen furnaces (BOFs) are widely used to produce steel from hot metal. The process typically has limited automation which leads to sub-optimal operation. Economically optimal operation can be potentially achieved by using a dynamic optimization framework to provide operators the best combination of input trajectories. In this paper, a first-principles based dynamic model for the BOF that can be used within the dynamic optimization routine is described. The model extends a previous work by incorporating a model for slag formation and energy balances. In this new version of the mathematical model, the submodel for the decarburization in the emulsion zone is also modified to account for recent findings, and an algebraic equation for the calculation of the calcium oxide saturation in slag is developed. The dynamic model is then used to simulate the operation of two distinct furnaces. It was found that the prediction accuracy of the developed model is significantly superior to its pr... [more]
Integrated Method of Monitoring and Optimization of Steam Methane Reformer Process
Nenad Zečević, Nenad Bolf
June 10, 2020 (v1)
Keywords: ammonia production, numerical modelling, Simulation, steam methane reforming
Reforming of natural gas with steam represents the most energy-intensive part of ammonia production. An integrated numerical model for calculating composition of primary reforming products with cross-checking of outlet methane molar concentration, heat duty, maximum tube wall temperature, tube pressure drops, and approach to equilibrium was set up involving production parameters. In particular, the model was used for continuous monitoring and optimization of a steam methane reformer (SMR) catalyst in ammonia production. The calculations involve the solution of material and energy balance equations along with reaction kinetic expressions. Open source code based on Matlab file was used for modelling and calculation of various physical properties of the reacting gases. One of the main contributions is development of the rapid integrated method for data exchange between any distributed control system (DCS) and the model to accomplish continuous monitoring and optimization of SMR catalyst a... [more]
Intelligent Colored Token Petri Nets for Modeling, Control, and Validation of Dynamic Changes in Reconfigurable Manufacturing Systems
Husam Kaid, Abdulrahman Al-Ahmari, Zhiwu Li, Reggie Davidrajuh
May 22, 2020 (v1)
Keywords: colored Petri net, Modelling, Reconfigurable manufacturing system, Simulation
The invention of reconfigurable manufacturing systems (RMSs) has created a challenging problem: how to quickly and effectively modify an RMS to address dynamic changes in a manufacturing system, such as processing failures and rework, machine breakdowns, addition of new machines, addition of new products, removal of old machines, and changes in processing routes induced by the competitive global market. This paper proposes a new model, the intelligent colored token Petri net (ICTPN), to simulate dynamic changes or reconfigurations of a system. The main idea is that intelligent colored tokens denote part types that represent real-time knowledge about changes and status of a system. Thus, dynamic configurations of a system can be effectively modeled. The developed ICTPN can model dynamic changes of a system in a modular manner, resulting in the development of a very compact model. In addition, when configurations appear, only the changed colored token of the part type from the current mo... [more]
Simulation of Solid Oxide Fuel Cell Anode in Aspen HYSYS—A Study on the Effect of Reforming Activity on Distributed Performance Profiles, Carbon Formation, and Anode Oxidation Risk
Khaliq Ahmed, Amirpiran Amiri, Moses O. Tadé
May 2, 2020 (v1)
Keywords: anode oxidation, carbon formation, internal reforming, Simulation, SOFC
A distributed variable model for solid oxide fuel cell (SOFC), with internal fuel reforming on the anode, has been developed in Aspen HYSYS. The proposed model accounts for the complex and interactive mechanisms involved in the SOFC operation through a mathematically viable and numerically fast modeling framework. The internal fuel reforming reaction calculations have been carried out in a plug flow reactor (PFR) module integrated with a spreadsheet module to interactively calculate the electrochemical process details. By interlinking the two modules within Aspen HYSYS flowsheeting environment, the highly nonlinear SOFC distributed profiles have been readily captured using empirical correlations and without the necessity of using an external coding platform, such as MATLAB or FORTRAN. Distributed variables including temperature, current density, and concentration profiles along the cell length, have been discussed for various reforming activity rates. Moreover, parametric estimation of... [more]
CFD Applications in Energy Engineering Research and Simulation: An Introduction to Published Reviews
Alfredo Iranzo
January 2, 2020 (v1)
Keywords: combustion, Computational Fluid Dynamics, energy engineering, heat transfer, Modelling, Renewable and Sustainable Energy, Simulation, thermal radiation, turbulence
Computational Fluid Dynamics (CFD) has been firmly established as a fundamental discipline to advancing research on energy engineering. The major progresses achieved during the last two decades both on software modelling capabilities and hardware computing power have resulted in considerable and widespread CFD interest among scientist and engineers. Numerical modelling and simulation developments are increasingly contributing to the current state of the art in many energy engineering aspects, such as power generation, combustion, wind energy, concentrated solar power, hydro power, gas and steam turbines, fuel cells, and many others. This review intends to provide an overview of the CFD applications in energy and thermal engineering, as a presentation and background for the Special Issue “CFD Applications in Energy Engineering Research and Simulation” published by Processes in 2020. A brief introduction to the most significant reviews that have been published on the particular topics is... [more]
Effect of Pre-Combustion Chamber Nozzle Parameters on the Performance of a Marine 2-Stroke Dual Fuel Engine
Hao Guo, Song Zhou, Majed Shreka, Yongming Feng
January 2, 2020 (v1)
Keywords: Computational Fluid Dynamics, dual-fuel engine, pre-combustion chamber, Simulation, two-stroke
In recent years and with the increasing rigor of the International Maritime Organization (IMO) emission regulations, the shipping industry has focused more on environment-friendly and efficient power. Low-pressure dual-fuel (LP-DF) engine technology with high efficiency and good emissions has become a promising solution in the development of marine engines. This engine often uses pre-combustion chamber (PCC) to ignite natural gas due to its higher ignition energy. In this paper, a parametric study of the LP-DF engine was proceeded to investigate the design scheme of the PCC. The effect of PCC parameters on engine performance and emissions were studied from two aspects: PCC nozzle diameter and PCC nozzle angle. The results showed that the PCC nozzle diameter affected the propagation of the flame in the combustion chamber. Moreover, suitable PCC nozzle diameters helped to improve flame propagation stability and engine performance and reduce emissions. Furthermore, the angle of the PCC no... [more]
Hybrid Integrations of Value Stream Mapping, Theory of Constraints and Simulation: Application to Wooden Furniture Industry
Emad Alzubi, Anas M. Atieh, Khaleel Abu Shgair, John Damiani, Sima Sunna, Abdallah Madi
December 16, 2019 (v1)
Keywords: bottleneck detection, OEE, Simulation, value stream map (VSM), wooden furniture manufacturing case study
This paper studies manufacturing processes in a wooden furniture manufacturing company. The company suffers from long manufacturing lead times and an unbalanced production line. To identify sources of waste and delay value stream mapping (VSM) and a discrete event simulation model is implemented. VSM is used to visualize and analyze the major processes of the company and provide quantifiable KPIs; the manufacturing lead-time and then Overall Equipment Effectiveness (OEE) settings. A discrete event simulation model is then built to analyze the company on a wider scale and provide the data required to identify bottlenecks. Building on the data gathered from the production lines and the simulation model, two-bottleneck detection methods are used, the utilization method, and the waiting time method. Then based on the comparison of the two methods a third bottleneck detection is utilized; the scenario-based method, to identify the primary and secondary bottlenecks. After the bottlenecks are... [more]
Development of an Electric Arc Furnace Simulator Based on a Comprehensive Dynamic Process Model
Thomas Hay, Thomas Echterhof, Ville-Valtteri Visuri
December 13, 2019 (v1)
Keywords: electric arc furnace, process model, Simulation, steelmaking
A simulator and an algorithm for the automatic creation of operation charts based on process conditions were developed on the basis of an existing comprehensive electric arc furnace process model. The simulator allows direct user input and real-time display of results during the simulation, making it usable for training and teaching of electric arc furnace operators. The automatic control feature offers a quick and automated evaluation of a large number of scenarios or changes in process conditions, raw materials, or equipment used. The operation chart is adjusted automatically to give comparable conditions at tapping and allows the assessment of the necessary changes in the operating strategy as well as their effect on productivity, energy, and resource consumption, along with process emissions.
Analysis of Power Loss and Improved Simulation Method of a High Frequency Dual-Buck Full-Bridge Inverter
Zhun Meng, Yi-Feng Wang, Liang Yang, Wei Li
December 10, 2019 (v1)
Keywords: dual-buck inverter, grid-connected generation, high frequency conversion, loss analysis, SiC power device, Simulation
A high frequency dual-buck full-bridge inverter for small power renewable energy application is proposed in this paper. A switching frequency of 400 kHz is achieved with the adoption of the SiC power device. A two-pole two-zero (2P2Z) compensator is employed in the outer voltage loop to generate the current reference for inner current loop. A 3P3Z compensator is adopted in the inner current loop to track the current reference. A systematic way for calculating the losses of high frequency inverter is presented, and the losses of the components are thoroughly analyzed. The turn-on and turn-off procedures of the inverter are discussed in detail. The losses caused by high frequency are calculated accurately, and the loss distribution is established as well. The procedure of the loss analysis gives a practical example for calculating the loss of similar type inverters. Moreover, deviation between pulse width modulation (PWM) control signal and switching response in high frequency switching... [more]
Simulation of Ion Exchange Resin with Finite Difference Methods
Yawen Zhu, Bobo Liu, Ruichao Peng, Yunbai Luo, Ping Yu
December 9, 2019 (v1)
Keywords: finite difference method, ion exchange, Matlab, Simulation
Ion exchange resin is used to remove potentially corrosive impurities from coolant in the first circuit of a nuclear power plant. After one operational cycle, the used and unused resin in the mixed bed is discarded as solid waste. The aim of this work is to create a mathematical model to predict the operational cycle time of the mixed bed resin for reducing unused resin discharge. A partial differential equation (PDE) was set up with the conservation of matter. A finite difference method was used to solve the PDE. Matlab was the programming and calculating tool used in this work. The data from solution were obtained at different time and space nodes. The model was then verified experimentally using different ions on exchange columns. Concentrations of K+, Mn2+, and Cl- were calculated to verify the validation of the model by comparing it with experimental data. The calculated values showed good consistency with the experimental value.
Process Cost Management of Alzheimer’s Disease
Hana Tomaskova, Martin Kopecky, Petra Maresova
November 24, 2019 (v1)
Keywords: Alzheimer’s disease, BPMN, process cost management, Simulation, system dynamics
Summary: Determining the cost of healthcare and social care for patients is a crucial issue for many parties; therefore, both public and private payments play a decisive role in patient care. The article deals with the analysis of the possibilities of the simulation of costs related to Alzheimer’s disease. This disease is highly variable, and the cost items vary considerably. Therefore, it is necessary to use simulation methods. The results of simulation models can then be implemented in sophisticated methods working with activity costs. Findings: Models for health and social care are specific. No significant re-engineering is expected in this area, so the models must be unambiguous and easy to understand for all representatives involved. Modeling of business processes is thus a suitable means for analysis in this area. The process cost calculation is built on two simulation models. The first model is the Business Process Model and Notation (BPMN), the results of which are verified in... [more]
Experimental and Numerical Study of Double-Pipe Evaporators Designed for CO2 Transcritical Systems
Junlan Yang, Shuying Ning
November 5, 2019 (v1)
Keywords: Carbon Dioxide, double-pipe evaporator, experimental study, heat transfer, Simulation
The performance of a CO2 double-pipe evaporator was studied through experiments and a simulation model that was established by the steady-state distribution parameter method and experimentally verified while using a CO2 transcritical water‒water heat pump system. The effects of different operating parameters on heat transfer performance were studied over a range of evaporation temperatures (−5 to 5 °C), mass velocity (100‒600 kg/m2s), and heat flux (5000‒15,000 W/m2). It was found that the dryout quality increased at a small evaporation temperature, a large mass velocity, and a small heat flux. The simulation yield means relative error (RE) of heat transfer for the evaporation temperature and that of the CO2 pressure drop for the chilled water inlet temperature were 5.21% and 3.78%, respectively. The effect of tube diameter on the performance of CO2 double-pipe evaporator is probed through simulations. At the same time, this paper defines a parameter α , which is the proportio... [more]
Special Issue: Modeling and Simulation of Energy Systems
Thomas A. Adams
October 26, 2019 (v1)
Keywords: Energy, energy systems, Modelling, operations, Optimization, process design, process systems engineering, Simulation
This editorial provides a brief overview of the Special Issue “Modeling and Simulation of Energy Systems.” This Special Issue contains 21 research articles describing some of the latest advances in energy systems engineering that use modeling and simulation as a key part of the problem-solving methodology. Although the specific computer tools and software chosen for the job are quite variable, the overall objectives are the same—mathematical models of energy systems are used to describe real phenomena and answer important questions that, due to the hugeness or complexity of the systems of interest, cannot be answered experimentally on the lab bench. The topics explored relate to the conceptual process design of new energy systems and energy networks, the design and operation of controllers for improved energy systems performance or safety, and finding optimal operating strategies for complex systems given highly variable and dynamic environments. Application areas include electric powe... [more]
Distinct and Quantitative Validation Method for Predictive Process Modeling with Examples of Liquid-Liquid Extraction Processes of Complex Feed Mixtures
Axel Schmidt, Jochen Strube
July 31, 2019 (v1)
Keywords: atpe, biologics, design-of-experiments, liquid-liquid extraction, Modelling, monte-carlo, quality-by-design, Simulation, validation, verification
As of today, industrial process development for liquid-liquid extraction and scale-up of extraction columns is based on an experimental procedure that requires tests in pilot-scale. This methodology consumes large amounts of material and time and the utilized scale-up equations are crude estimates including considerable safety margins. This approach is practical for well-known systems or low-value products coupled with high production scale, where such a scale-up methodology has less impact on the overall profitability. However, for new high-value products in biologics manufacturing, a process development based on process understanding and the use of validated process models is imperative. Therefore, a distinct and quantitative validation workflow for liquid-liquid extraction modeling is presented on the example of two complex feed mixtures. Monte-Carlo simulations based on the presented model parameter determination concept result for both examples in prediction accuracy comparable to... [more]
Modernizing the Undergraduate Process Design Curriculum
Thomas Alan Adams II
July 20, 2019 (v1)
Subject: Education
Keywords: Curriculum, Education, Modelling, Process Design, Process Synthesis, Simulation
In this talk, I give an overview of the chemical engineering curriculum at McMaster University as it relates to the 1.5 year process design sequence. The courses outside the design sequence were recently restructured and redesigned to create an environment with more modelling and algorithmic thinking/algorithmic problem solving. This includes a statistics course and a big data / machine learning course. The end result is that the design sequence is able to focus on state of the art tools and methods for process design because students receive many fundamental principles before the design sequence begins.
Analysis of Influencing Factors of Occupational Safety and Health in Coal Chemical Enterprises Based on the Analytic Network Process and System Dynamics
Kai Yu, Lujie Zhou, Chen Hu, Linlin Wang, Weiqiang Jin
April 15, 2019 (v1)
Subject: Energy Policy
Keywords: analytic network process, management and control measures, occupational safety and health, Simulation, system dynamics
In the production process of coal chemical enterprises, there are factors such as dust, poisons, as well as toxic and harmful gases, which seriously restrict the safety and health of employees. It is urgent to strengthen research on occupational safety and health (OSH) of coal chemical enterprises. Research on the influencing factors is very important to improve the level of OSH in coal chemical enterprises. Therefore, this paper analyzed the factors affecting OSH of coal chemical enterprises from four aspects: “human⁻machine⁻environment⁻management„. Then, an influencing factor indicator system was constructed. The weights of the indicator were analyzed using the Analytic Network Process (ANP). On this basis, the primary and secondary indicators of the influencing factors were ranked. Subsequently, the weights of ANP were taken as the influence coefficient between variables, and the System Dynamics (SD) model of OSH control measures was established and analyzed. According to the weight... [more]
Simulation and Test Bed of a Low-Power Digital Excitation System for Industry 4.0
Jun-Ho Huh, Hoon-Gi Lee
April 8, 2019 (v1)
Keywords: computer architecture, digital excitation system, Industry 4.0, low power, operating system, Simulation, smart grid, Test Bed
Since modeling and simulation are the two most effective tools that can be used in the design or analysis process, they play a vital role in developing such system. In many cases, they are the only possible means of making a safe engineering decision for a new concept of process for a large-scale system. Elsewhere, they are used as a critical element in the analysis of energy systems or to suggest a method of developing a novel and effective energy system model. Thus, in this study, simulations and test bed experiment were carried out to assess a low-power digital excitation system in order to validate its effectiveness. The excitation systems currently used by most of the power stations in the Republic of Korea were installed during the 1970s or 1980s. Unfortunately, it is difficult to seek technical assistance for them as they depend on foreign technologies, requiring a large sum to be paid when requesting one or more engineers to be dispatched. As such, technical updates have always... [more]
Cold Storage for a Single-Family House in Italy
Luigi Mongibello, Giorgio Graditi
February 27, 2019 (v1)
Keywords: cold storage, cold water, economic analysis, PCM, Simulation, single-family house
This work deals with the operation, modeling, simulation, and cost evaluation of two different cold storage systems for a single-family house in Italy, that differ from one another on the cold storage material. The two materials used to perform the numerical simulations of the cold storage systems are represented by cold water and a phase change material (PCM), and the numerical simulations have been realized by means of numerical codes written in Matlab environment. The main finding of the present work is represented by the fact that, for the considered user characteristics, and under the Italian electricity tariff policy, the use of a proper designed cold storage system characterized by an effective operation strategy could represent a viable solution from an economical point of view.
Three-Dimensional Finite-Element Analysis of the Short-Time and Peak Withstand Current Tests in Substation Connectors
Francesca Capelli, Jordi-Roger Riba, Joan Pérez
November 28, 2018 (v1)
Keywords: connector, finite element method, peak withstand current test, short-time withstand current test, Simulation, substation
Power devices intended for high-voltage systems must be tested according to international standards, which includes the short-time withstand current test and peak withstand current test. However, these tests require very special facilities which consume huge amounts of electrical power. Therefore, mathematical tools to simulate such tests are highly appealing since they allow reproducing the electromagnetic and thermal behavior of the test object in a fast and economical manner. In this paper, a three-dimensional finite element method (3D-FEM) approach to simulate the transient thermal behavior of substation connectors is presented and validated against experimental data. To this end, a multiphysics 3D-FEM method is proposed, which considers both the connector and the reference power conductors. The transient and steady-state temperature profiles of both the conductors and connector provided by the 3D-FEM method prove its suitability and accuracy as compared to experimental data provid... [more]
Shielding Effectiveness Simulation of Small Perforated Shielding Enclosures Using FEM
Zdeněk Kubík, Jiří Skála
November 27, 2018 (v1)
Keywords: electromagnetic compatibility (EMC), finite element method (FEM), measurement, shielding effectiveness (SE), shielding enclosure, Simulation
Numerical simulation of shielding effectiveness (SE) of a perforated shielding enclosure is carried out, using the finite element method (FEM). Possibilities of model definitions and differences between 2D and 3D models are discussed. An important part of any simulation is verification of the model results—here the simulation result are verified in terms of convergence of the model in dependence on the degrees of freedom (DOF) and by measurements. The experimental method is based on measurement of electric field inside the enclosure using an electric field probe with small dimensions is described in the paper. Solution of an illustrative example of SE by FEM is shown and simulation results are verified by experiments.
Progress of Space Charge Research on Oil-Paper Insulation Using Pulsed Electroacoustic Techniques
Chao Tang, Bo Huang, Miao Hao, Zhiqiang Xu, Jian Hao, George Chen
October 23, 2018 (v1)
Keywords: insulation oil, insulation paper, moisture content, pulsed electroacoustic technique (PEA), Simulation, space charge, temperature
This paper focuses on the space charge behavior in oil-paper insulation systems used in power transformers. It begins with the importance of understanding the space charge behavior in oil-paper insulation systems, followed by the introduction of the pulsed electrostatic technique (PEA). After that, the research progress on the space charge behavior of oil-paper insulation during the recent twenty years is critically reviewed. Some important aspects such as the environmental conditions and the acoustic wave recovery need to be addressed to acquire more accurate space charge measurement results. Some breakthroughs on the space charge behavior of oil-paper insulation materials by the research team at the University of Southampton are presented. Finally, future work on space charge measurement of oil-paper insulation materials is proposed.
Maintenance Factor Identification in Outdoor Lighting Installations Using Simulation and Optimization Techniques
Ana Ogando-Martínez, Javier López-Gómez, Lara Febrero-Garrido
September 21, 2018 (v1)
Keywords: artificial lighting, calibration, GenOpt, radiance, Simulation, street light points
This document addresses the development of a novel methodology to identify the actual maintenance factor of the luminaires of an outdoor lighting installation in order to assess their lighting performance. The method is based on the combined use of Radiance, a free and open-source tool, for the modeling and simulation of lighting scenes, and GenOpt, a generic optimization program, for the calibration of the model. The application of this methodology allows the quantification of the deterioration of the road lighting system and the identification of luminaires that show irregularities in their operation. Values lower than 9% for the error confirm that this research can contribute to the management of street lighting by assessing real road conditions.
Internet of Energy Approach for Sustainable Use of Electric Vehicles as Energy Storage of Prosumer Buildings
Evgeny Nefedov, Seppo Sierla, Valeriy Vyatkin
September 21, 2018 (v1)
Keywords: distributed energy storage, electric vehicles, internet of energy, photovoltaic generation, prosumer, Simulation, smartgrid, vehicle-to-building, vehicle-to-grid
Vehicle-to-building (V2B) technology permits bypassing the power grid in order to supply power to a building from electric vehicle (EV) batteries in the parking lot. This paper investigates the hypothesis stating that the increasing number of EVs on our roads can be also beneficial for making buildings sustainably greener on account of using V2B technology in conjunction with local photovoltaic (PV) generation. It is assumed that there is no local battery storage other than EVs and that the EV batteries are fully available for driving, so that the EVs batteries must be at the intended state of charge at the departure time announced by the EV driver. Our goal is to exploit the potential of the EV batteries capacity as much as possible in order to permit a large area of solar panels, so that even on sunny days all PV power can be used to supply the building needs or the EV charging at the parking lot. A system architecture and collaboration protocols that account for uncertainties in EV... [more]
SOLIS—A Novel Decision Support Tool for the Assessment of Solar Radiation in ArcGIS
Jan K. Kazak, Małgorzata Świąder
September 21, 2018 (v1)
Keywords: ArcGIS, decision support system, photovoltaics, Renewable Energy, Simulation, solar radiation, sustainable development
The global Sustainable Development Goals influence the implementation of energy development strategies worldwide. However, in order to support local stakeholders in sustainable energy development strategies and climate change adaptation plans and the implementation of policies, there is a need to equip local decision makers with tools enabling the assessment of sustainable energy investments. In order to do so, the aim of this study is to create a novel tool for the assessment of solar radiation (SOLIS) in ArcGIS. The SOLIS tool builds on the existing ArcGIS algorithm by including input data conversion and post-processing of the results. This should expand the group of potential users of solar radiation analyses. The self-filtering tool excludes surfaces that are not suitable for solar energy investments due to geometrical reasons. The reduction of the size of the output data is positive for technical reasons (speed of the calculation and occupied storage place) and for cognitive reaso... [more]
Identification of the Heat Equation Parameters for Estimation of a Bare Overhead Conductor’s Temperature by the Differential Evolution Algorithm
Mirza Sarajlić, Jože Pihler, Nermin Sarajlić, Gorazd Štumberger
September 21, 2018 (v1)
Keywords: conductor temperature, measurement, Optimization, overhead transmission line, parameter identification, Simulation
This paper deals with the Differential Evolution (DE) based method for identification of the heat equation parameters applied for the estimation of a bare overhead conductor`s temperature. The parameters are determined in the optimization process using a dynamic model of the conductor; the measured environmental temperature, solar radiation and wind velocity; the current and temperature measured on the tested overhead conductor; and the DE, which is applied as the optimization tool. The main task of the DE is to minimise the difference between the measured and model-calculated conductor temperatures. The conductor model is relevant and suitable for the prediction of the conductor temperature, as the agreement between measured and model-calculated conductor temperatures is exceptional, where the deviation between mean and maximum measured and model-calculated conductor temperatures is less than 0.03 °C.
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