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1
Shukla, A. K., A. Mondal, and A. Upadhyaya. "Numerical modeling of microwave heating." Science of Sintering 42, no. 1 (2010): 99–124. http://dx.doi.org/10.2298/sos1001099s.
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The present study compares the temperature distribution within cylindrical samples heated in microwave furnace with those achieved in radiatively-heated (conventional) furnace. Using a two-dimensional finite difference approach the thermal profiles were simulated for cylinders of varying radii (0.65, 6.5, and 65 cm) and physical properties. The influence of susceptor-assisted microwave heating was also modeled for the same. The simulation results reveal differences in the heating behavior of samples in microwaves. The efficacy of microwave heating depends on the sample size and its thermal conductivity.
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Bukhmirov, V. V., M. H. Suleimanov, E. N. Bushuev, O. B. Kolibaba, and N. P. Gusenkova. "Development of modern method to calculate thermal performance of chamber heating furnace." Vestnik IGEU, no. 5 (October 31, 2022): 5–11. http://dx.doi.org/10.17588/2072-2672.2022.5.005-011.
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Experiments are often considered as the way to find rational heating modes at manufacturing enterprises. Unlike experimental methods, modern calculation methods use mathematical modeling of physical and chemical processes in heating furnaces. It allows to reduce the time of the research and it is less resource intensive. A mathematical model is proposed to find rational operation modes of thermal furnaces according to the specified criterion. The model considers the porosity of the heated material and the flow of the furnace atmosphere through it. Finite difference method and the zonal method to calculate complex heat transfer is used for numerical implementation of the model. A mathematical model of the thermal operation of a thermal furnace to heat bulk cages has been developed, considering the filtration of combustion products. The developed mathematical model is designed to find new modes of thermal operation of the heating furnace, which provide a specified quality of the final product with a minimum fuel consumption or maximum furnace productivity according to the given fuel consumption rate.
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Eric, Aleksandar, Stevan Nemoda, Mirko Komatina, Branislav Repic, and Dragoljub Dakic. "Modeling of transport processes in the cigarette principle combustion furnace." Thermal Science 23, Suppl. 5 (2019): 1499–510. http://dx.doi.org/10.2298/tsci180226318e.
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This paper presents numerical and experimental investigations of complex and interrelated physical and chemical phenomena that occur during combustion of baled soybean residue in the furnace with the cigarette type of combustion. The result of comprehensive research is reactive flow model of biomass combustion inside furnace. Model is described by set of PDE which define momentum, heat and mass transfer processes in porous and fluid system. The main aim of developed CFD model is numerical simulation of combustion process inside the cigarette furnace. It is also used to provide deeper insight in complex processes occurring during biomass combustion. Verification of proposed numerical model was performed through comprehensive experimental tests on the experimental-industrial plant of 1.5 MW boiler for heating the greenhouses in the Agricultural Corporation in Belgrade. The tests included measurement of flow rate and air and flue gas temperature input and output values on the furnace that are taken as the boundary conditions of the developed model. Comparison of the experimental results shows satisfactory agreement with numerical results (the maximum relative deviation of calculation and measurement temperatures are 10-45%), therefore the developed mathematical model could be used to analyse the effects of structural and parametric (fuel composition, power rate, air excess etc.) changes of the facility, from the standpoint of energy efficiency and ecology.
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Song, Kezhou, and Ari Jokilaakso. "CFD Modeling of Multiphase Flow in an SKS Furnace with New Tuyere Arrangements." Metallurgical and Materials Transactions B 53, no. 1 (2021): 253–72. http://dx.doi.org/10.1007/s11663-021-02362-9.
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AbstractThere has been a great deal of focus on the optimization of tuyere arrangements in SKS bottom blown copper smelting furnaces since the last decade, as the improved furnace operation efficiency of SKS technology has potential that cannot be ignored. New –x + 0 + x deg tuyere arrangements with 14 tuyeres are proposed in this research paper. Using a previously verified numerical model, CFD tests on the velocity distribution and wall shear stress for scaled-down SKS furnace models were conducted, with a constant total volumetric gas flow rate, and different operating parameters and furnace cross-section geometries. The results indicate that, at a relatively low gas injection speed compared with the previously optimized tuyere arrangement, although the –x +0 +x deg tuyere arrangements are unable to supply enhanced agitation in the typical round furnaces, they achieve better performance in elliptical furnaces. At a comparatively higher gas injection speed, the – x + 0 + x deg tuyere arrangements can improve the agitation performance in a round furnace while maintaining an acceptable wall shear stress on the bottom and side wall. The agitation enhancement with the − x +0 +x deg tuyere arrangements can essentially be attributed to stronger interactions between bubble plumes and furnace side walls. To further exploit the advantages of the new tuyere arrangements, an optimized tuyere angle was confirmed by a full-scale furnace model simulation.
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Perevezentsev, G. A., V. A. Gorbunov, and O. B. Kolibaba. "Development of a mathematical model of heat-treating furnaces with sole flues and a numerical study of its operation parameters." Vestnik IGEU, no. 4 (2019): 22–30. http://dx.doi.org/10.17588/2072-2672.2019.4.022-030.
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The main element of metalworking, engineering and other industries is heating and heat-treating furnaces. An array of workpieces that are loaded into the furnace includes bulk tanks with different parameters. The existing designs of heating furnaces have a number of disadvantages, one of which is the lack of heat carrier filtration in the vertical direction. However, this feature can be found in the developed design of the batch furnace with sole flues. The aim of the work is to develop and study the parameters of a mathematical model of the heating process of a bulk tank in a heat-treating furnace with sole flues. The paper describes and studies a mathematical model of a heat-treating furnace equipped with special sole flues. The bulk tank model is built based on a fractal structure, in particular the Menger sponge. To solve the problem of deter-mining the temperature field of the bulk tank, we used a numerical calculation of heat exchange based on the finite-difference method, also called the grid method. For this purpose, a new design of the batch furnace with hearth chambers has been proposed. As a result of mathematical modeling of the heating process, we have obtained a graph reflecting the temperature field of the bulk tank on the surface and in the heating center. We have also compared the temperature regime of bulk tank heating under normal conditions and in conditions of additional heat carrier filtration through the flues from the hearth chambers to the furnace hearth. The reliability of the results is confirmed by comparing the numerical simulation results and the results of the physical experiment. The error is not more than 10 %. The efficiency of the heat-treating furnace is improved by additional heat carrier filtration through special channels in the furnace sole. The obtained mathematical model can be used to calculate different heating modes in heat-treating furnaces and to develop technological maps of heating bulk tanks with different porosity values.
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V. Salomatov, Vladimir, Oleg V. Sharypov, Igor S. Anufriev, Yuri A. Anikin, and Kh Enkhjargal. "Physical Modeling of Interior Aerodynamics of Vortex Furnace of Energy Steam Generator." Siberian Journal of Physics 6, no. 1 (2011): 60–65. http://dx.doi.org/10.54362/1818-7919-2011-6-1-60-65.
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The work is devoted to experimental research of interior aerodynamics of steam generator vortex furnace with using of laser Doppler anemometry method. Measurements of flow velocity field have been carried out on the isothermal model, which is geometrically similar to one section of the experimental-industrial boiler TPE-427 of Novosibirsk TPS-3 (on a scale of 1:15). The obtained results have been compared with heat-loss anemometry and numerical calculation results
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Prokhorov, V. B., N. E. Fomenko, and M. V. Fomenko. "Development of a simplified methodology for furnace aerodynamics with vortex combustion of organic fuel modeling." Journal of Physics: Conference Series 2088, no. 1 (2021): 012016. http://dx.doi.org/10.1088/1742-6596/2088/1/012016.
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Abstract This paper describes the process of developing a simplified methodology for furnace aerodynamics during the development or modernization of combustion schemes with direct-flow burners. This technique is based on the use of numerical modeling of air movement and turbulence phenomena in the furnace volume and allows for a relatively short period of time to analyze a large number of options for the burners and nozzles location. This is its advantage in comparison with the use of experimental modeling or numerical simulation with combustion when analyzing a variety of schemes. The model was developed on the basis of validated results of combustion processes numerical simulation in the K-50 boiler furnace. The paper presents the results of calculations performed for several variants of the simplified methodology. For further use, the option that best corresponds to full-scale studies taking into account the fuel combustion process has been selected. The main states of the methodology are formulated.
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Anikin, Yuriy, Igor Anufriev, Denis Krasinsky, Vladimir Salomatov, Evgeny Shadrin, and Oleg Sharypov. "Physical and Numerical Modelling of Internal Aerodynamics of the Vortex Furnace with Distributed Tangential Input of Burner Streams." Siberian Journal of Physics 8, no. 2 (2013): 86–94. http://dx.doi.org/10.54362/1818-7919-2013-8-2-86-94.
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The work is devoted to experimental and numerical modelling of internal aerodynamics of a new type furnace for the thermal power plant steam generator with technology of pulverized-coal combustion in vortex flow. Measurements of aerodynamic features of the flow in the laboratory air isothermal model of the furnace have been performed with twocomponent laser Doppler velocimeter. Numerical simulation of three-dimensional turbulent isothermal flow in the laboratory model has been carried out with the use of CFD package FLUENT. Detailed 3-D flow structure in the studied model has been obtained. The agreement between numerical predictions and measurements on mean flow velocity distributions has been shown
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Kolibaba, O. B., D. A. Dolinin, R. N. Gabitov, and M. M. Chizhikova. "Development of furnace design to dispose municipal solid waste and study of its operation modes." Vestnik IGEU, no. 4 (August 31, 2022): 5–13. http://dx.doi.org/10.17588/2072-2672.2022.4.005-013.
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Background. Pyrolysis is a promising environmentally friendly thermal method to process municipal solid waste (MSW). Pyrolysis makes it possible to obtain a combination of solid, liquid, and gaseous products in various proportions by changing the operating parameters of the process. Thermal processing of MSW is carried out in special furnaces, thermal reactors. At present, the processes of the pyrolysis technology Purox, Torrax Noell and others are carried out in thermal reactors of various designs that have their own advantages and disadvantages. The design of a furnace is to meet several requirements, such as high productivity, efficiency of operation, ensuring the specified technological conditions of the process, etc. The designed furnace is to meet modern requirements of science and technology in the field of heat and mass transfer theory, hydrodynamics, and technical aesthetics. Materials and methods. The studies have been carried out using the methods of physical and mathematical modeling, the ANSYS software package of finite element analysis. Results. Based on the results of physical and numerical studies, the values of the efficiency of the pyrolysis furnace have been obtained when MSW is heated at speeds of 5, 10 and 15 оС/min. Based on the results a rational operating mode of the installation has been chosen with a heating rate of 10 оС/min. Conclusions. The use of pyrolysis technology for waste disposal will reduce CO2 emissions by 17 % compared to traditional incineration. The proposed design of a pyrolysis furnace for the disposal of pre-prepared waste contributes to energy efficiency improvement of the process.
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Dzhyoiev, Rafael, Andrei Redko, Igori Redko, et al. "Aerodynamic Characteristics of the Combustion Process of Sawdust in a Vortex Furnace with Counter-Swirling Flows." Problems of the Regional Energetics, no. 4(52) (November 2021): 68–78. http://dx.doi.org/10.52254/1857-0070.2021.4-52.07.
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The aim of this work is to study the working processes of burning the low-quality fuels, namely, the saw dust in the swirling-type furnaces with an opposite twisted motion of the air. The goal was achieved using the physical and mathematical modeling of the flows interaction. The article presented the results of numerical study of aerodynamic characteristics of burning the saw dust in the swirling-type furnace with the opposite twisted air flows. For the research, the facility was used for the saw dust burning with the air supply into the lower and upper zones of burning. The most essential result of the work was modeling of the working process at the ratio of the flows of the primary air and secondary air without the fuel admixture, equal to 0.2. The tangential rate of the flow changed according to the horizontal sections from 3-5 m/s to 40-42 m/s and with respect to the furnace height from 51 m/s to 30 m/s. The average angular rate of the mixture changed relatively the furnace height in the ranges of 171-500 l/s to 100—300 l/s. The significance of the results obtained consists in determination of the possibility of increasing the efficiency of the work of the furnace facilities at the expense of the introduction of the primary and secondary air flows. In this situation, the optimal ratio of consumptions of primary and secondary air was 0.2. Thus, in this work the consumption of primary air was 1.285 kg/s, the consumption of the secondary air was 0.255 kg/s.
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Gil, Andrey V., Kirill I. Maltsev, Alexander S. Zavorin, and Alexander V. Starchenko. "Mathematical simulation of furnace processes during fired pulverized coal." Tyumen State University Herald. Physical and Mathematical Modeling. Oil, Gas, Energy 8, no. 3 (2022): 44–58. http://dx.doi.org/10.21684/2411-7978-2022-8-3-44-58.
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The article presents the study of combustion and heat transfer processes in large-scale objects are extremely difficult both analytically and experimentally. The combustion of non-design coals in boiler units is often accompanied by a decrease in the completeness of fuel burnup, undesirable redistribution of heat flows and other negative factors due to different thermal characteristics of the fuel. The possibility of effective burnout of polyfractional non-design solid fuel in the combustion chamber of a boiler unit with solid ash removal is considered on the basis of a numerical study of jointly occurring aerothermochemical processes. The problem of numerical modeling of the staged burnout of coal particles is solved, starting from the evaporation of the moisture contained in them to the burning out of their coke residue when moving in the carrier phase. Numerical studies of physical and chemical processes in the combustion chamber were carried out for three loads (50%, 70%, 100%) based on the developed FIRE 3D calculation complex. The Euler-Lagrange model for a dusty flow is applied, the closure of the averaged Navier-Stokes equations is performed by the k-ε turbulence model, the second order of accuracy is used in numerical calculations. The main results of three-dimensional modeling are presented in the form of velocity and temperature fields, the distribution of O2 and CO concentrations along the height of the furnace volume. The results of mathematical modeling showed good agreement with the available analytical values. Based on the data obtained, it can be stated that it is possible to organize the combustion of non-design fuel in the boiler unit under consideration. It has been established that when operating at loads below the nominal, a redistribution of burner jets is observed, which negatively affects the reliability and efficiency of the boiler. To increase the efficiency of the boiler unit at reduced loads, a wider study of options for redistributing the proportions of the fuel-air mixture and secondary air is necessary.
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Solovei, Vladyslav. "Numerical analysis of the thermal-elastic-plastic state of electrical contact gasket made from dispersion-reinforced composite materials using the fusioned deposition modeling method." Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving, no. 4 (December 23, 2022): 21–31. http://dx.doi.org/10.20535/2617-9741.4.2022.269748.
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The article presents the results of a theoretical study on determining the suitability of using electrical contact gaskets (ECG) in industrial conditions (Castner direct graphitization furnaces), made of coke-pitch composite using additive technologies based on the Fused Deposition Modeling (FDM) method.
 Numerical analysis of the physical state of ECG under the conditions of industrial application was performed on the basis of the mathematical statement of the thermo-elastic-plasticity problem and the algorithm of implicit inverse mapping of its solution based on the finite element method in the Mathcad programming environment. To construct the geometry and tetraid mesh of the ECG model, a freely open program code was used - the Gmsh CAD system for grid generation, and for the visualization of the results of physical field calculations, the free open program code ParaView was used.
 The study of the thermo-elastic-plastic state of ECG under the conditions of the graphitization process in Castner furnaces was carried out in the temperature range up to 900 °С, at which the thermoplastic properties of the material are manifested. At the same time, such physical fields of ECG were analyzed as temperature distribution, resulting displacements, equivalent elastic stresses according to Mises, equivalent total, elastic and plastic deformations according to Mises, and the volume fraction of ECG material in a plastic state, depending on the temperature level and radial gradient temperatures (radial temperature difference) of electrical contact gaskets.
 Numerical simulation of the thermo-elastic-plastic state of the ECG was carried out under the conditions of force loading by external pressure on the lateral surface of the gasket of 2.5 MPa and different values of the radial temperature difference in the range of 15–90 °C in the temperature range up to 900 °C. It was established that: at the stages of formation of semi-coke and coke in the material of the coke-pitch composite ECG under the thermomechanical conditions of operation of the Kastner furnace, a margin of strength of not less than unity was obtained; with the subsequent increase in the temperature level in the Castner furnace to 3000 °C and above, the raw material of ECG, as a result of thermal destruction, has already turned into coke and, therefore, its mechanical properties have become close to the mechanical properties of electrode blanks in columns that are subjected to graphitization. This gives reason to assert that the ECGs will not be mechanically destroyed during the entire graphitization campaign of the Castner furnace.
 On the basis of the analysis of the results of numerical simulation, the possibility of using ECGs made from dispersion-reinforced composite materials (coke-pitch mixtures) by the FDM method in the technology of graphitizing electrode products according to the Сastner method is substantiated.
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Wang, Jing, Nai Lu Chen, and Xue Xiong Shan. "Numerical Simulation and Measurement of Velocity Distribution in a Gas Nitriding Furnace." Solid State Phenomena 118 (December 2006): 331–36. http://dx.doi.org/10.4028/www.scientific.net/ssp.118.331.
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During gas nitriding process, homogeneous velocity distribution is required to ensure uniformity of gas content and temperature fields, which is one of key factors for fine processing results. In order to understand the velocity distribution in a gas nitriding furnace, which was equipped with a stirring motor-driven fan on top, we studied different situations with several fan motor rotational speeds. The whole furnace was modeled by computational fluid dynamics software package FLUENT. The fan boundary condition and standard k-ε equation are chosen for modeling to generate better results in our case. A digital turbine anemometer is used to measurment velocities at various places inside the furnace. Good agreements were found between simulation and measurement.
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Han, Jiade, Lingbo Zhu, Yiping Lu, Yu Mu, Azeem Mustafa, and Yajun Ge. "Numerical Simulation of Combustion in 35 t/h Industrial Pulverized Coal Furnace with Burners Arranged on Front Wall." Processes 8, no. 10 (2020): 1272. http://dx.doi.org/10.3390/pr8101272.
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Coal-fired industrial boilers should operate across a wide range of loads and with a higher reduction of pollutant emission in China. In order to achieve these tasks, a physical model including two swirling burners on the front wall and boiler furnace was established for a 35 t/h pulverized coal-fired boiler. Based on Computational Fluid Dynamics (CFD) theory and the commercial software ANSYS Fluent, mathematical modeling was used to simulate the flow and combustion processes under 75% and 60% load operating conditions. The combustion characteristics in the furnace were obtained. The flue gas temperature simulation results were in good agreement with experimental data. The simulation results showed that there was a critical distance L along the direction of the furnace depth (x) and Hc along the direction of the furnace height (y) on the burner axis. When x < L, the concentration of NO decreased sharply as the height increased. When y < Hc, the NO concentration decreased sharply with an increase in the y coordinate, while increasing dramatically with an area-weighted average gas temperature increase in the swirl combustion zone. This study provides a basis for optimizing the operation of nitrogen-reducing combustion and the improvement of burner structures.
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Luzi, Giovanni, Vinzenz Klapper, and Antonio Delgado. "Asymptotic Modeling of Optical Fibres: Annular Capillaries and Microstructured Optical Fibres." Fibers 11, no. 12 (2023): 104. http://dx.doi.org/10.3390/fib11120104.
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Microstructured optical fibres (MOFs) are a new type of optical fibres that possess a wide range of optical properties and many advantages over common optical fibres. Those are provided by unique structures defined by a pattern of periodic or quasi-periodic arrangement of air holes that run through the fibre length. In recent years, MOFs have opened up new possibilities in the field of optics and photonics, enabling the development of advanced devices and novel optical systems for different applications. The key application areas of MOFs vary from telecommunications and high-power energy transmission to quantum optics and sensing. The stack-and-draw method is a standard manufacturing technique for MOFs, where a preform is first manually created and then drawn in a sophisticated furnace into a fibre with the required final dimensions and position of the air holes. During the manufacturing process, experimenters can control only a few parameters, and mathematical models and numerical simulations of the drawing process are highly requested. They not only allow to deepen the understanding of physical phenomena occurring during the drawing process, but they also accurately predict the final cross-section shape and size of the fibre. In this manuscript, we assume thermal equilibrium between the furnace and the fibre and propose a functional form of the fibre temperature distribution. We utilise it with asymptotic mass, momentum, and evolution equations for free surfaces already available in the literature to describe the process of fibre drawing. By doing so, the complex heat exchange problem between the fibre and the furnace need not be solved. The numerical results of the whole asymptotic model overall agree well with experimental data available in the literature, both for the case of annular capillaries and for the case of holey fibres.
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Lahaye, Domenico, Prajakta Nakate, Kees Vuik, Franjo Juretić, and Marco Talice. "Modeling Conjugate Heat Transfer in an Anode Baking Furnace Using OpenFoam." Fluids 7, no. 4 (2022): 124. http://dx.doi.org/10.3390/fluids7040124.
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The operation of large industrial furnaces will continue to rely on hydrocarbon fuels in the near foreseeable future. Mathematical modeling and numerical simulation is expected to deliver key insights to implement measures to further reduce pollutant emissions. These measures include the design optimization of the burners, the dilution of oxidizer with exhaust gasses, and the mixing of natural gas with hydrogen. In this paper, we target the numerical simulation of non-premixed turbulent combustion of natural gas in a single heating section of a ring pit anode baking furnace. In previous work, we performed combustion simulations using a commercial flow simulator combined with an open-source package for the three-dimensional mesh generation. This motivates switching to a fully open-source software stack. In this paper, we develop a Reynolds-Averaged Navier-Stokes model for the turbulent flow combined with an infinitely fast mixed-is-burnt model for the non-premixed combustion and a participating media model for the radiative heat transfer in OpenFoam. The heat transfer to the refractory brick lining is taken into account by a conjugate heat transfer model. Numerical simulations provide valuable insight into the heat release and chemical species distribution in the staged combustion process using two burners. Results show that at the operating conditions implemented, higher peak temperatures are formed at the burner closest to the air inlet. This results in a larger thermal nitric-oxide concentration. The inclusion of the heat absorption in the refractory bricks results in a more uniform temperature on the symmetry plane at the center of the section. The peak in thermal nitric-oxides is reduced by a factor of four compared to the model with adiabatic walls.
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Zhao, Ming, Yuhua Pan, Aifu Zhao, Shili Zhang, Ping Ma, and Xin Feng. "CFD Modeling and Cold Physical Model Simulation on Single Molten Slag Ligament Disintegration into Droplets." Minerals 13, no. 2 (2023): 139. http://dx.doi.org/10.3390/min13020139.
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Aiming at the mode of liquid ligament disintegration into droplets in the process of the centrifugal granulation of molten blast furnace slag using a spinning cup, in order to gain an in-depth understanding of the behavior and mechanism of droplet formation by liquid ligament disintegration and to obtain appropriate conditions to control the size of the produced slag granules, a three-dimensional CFD model describing water–air two-phase flow with a free surface was established in this work for simulating the process of a single water ligament breakup into droplets under the action of gravity, surface tension and inertial forces, so as to compare with the process of a molten slag ligament disintegration into droplets due to centrifugal force exerted by the spinning cup. By studying the disintegration behavior and mechanism of a single water ligament, the similar phenomenon of a molten slag ligament disintegration is examined. The numerical simulation results on the breakup of a single water ligament show that the length of the ligament before its disintegration and the diameter of the droplets formed both increase with the increase of the velocity of the ligament initially exiting a capillary nozzle. In addition, an experimental set-up was established in the laboratory to conduct cold physical model simulation experiments on single water or liquid paraffin ligament disintegration. The experimental results are compared with the numerical simulation results so that the reliability of the CFD model is verified. The results of the present study show that, in the centrifugal granulation process of blast furnace slag using a spinning cup operated in the ligament disintegration mode, the breakup of a single molten slag ligament is very similar to that of a single water or liquid paraffin ligament, and both approximately follow the Rayleigh Disintegration Mechanism, which provides a theoretical basis for analyzing the breakup process of the ligaments of different liquids as references for guiding the operation of centrifugal granulation of molten slag.
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Nakate, Prajakta, Domenico Lahaye, and Cornelis Vuik. "The nitric oxide formation in anode baking furnace through numerical modeling." International Journal of Thermofluids 12 (November 2021): 100122. http://dx.doi.org/10.1016/j.ijft.2021.100122.
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Hamadeh, Hamzeh, Olivier Mirgaux, and Fabrice Patisson. "Detailed Modeling of the Direct Reduction of Iron Ore in a Shaft Furnace." Materials 11, no. 10 (2018): 1865. http://dx.doi.org/10.3390/ma11101865.
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This paper addresses the modeling of the iron ore direct reduction process, a process likely to reduce CO2 emissions from the steel industry. The shaft furnace is divided into three sections (reduction, transition, and cooling), and the model is two-dimensional (cylindrical geometry for the upper sections and conical geometry for the lower one), to correctly describe the lateral gas feed and cooling gas outlet. This model relies on a detailed description of the main physical–chemical and thermal phenomena, using a multi-scale approach. The moving bed is assumed to be comprised of pellets of grains and crystallites. We also take into account eight heterogeneous and two homogeneous chemical reactions. The local mass, energy, and momentum balances are numerically solved, using the finite volume method. This model was successfully validated by simulating the shaft furnaces of two direct reduction plants of different capacities. The calculated results reveal the detailed interior behavior of the shaft furnace operation. Eight different zones can be distinguished, according to their predominant thermal and reaction characteristics. An important finding is the presence of a central zone of lesser temperature and conversion.
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Akberdin, A. A., A. S. Kim, and R. B. Sultangaziev. "Planning of numerical and physical experiment in simulation of technological processes." Izvestiya Visshikh Uchebnykh Zavedenii. Chernaya Metallurgiya = Izvestiya. Ferrous Metallurgy 61, no. 9 (2018): 737–42. http://dx.doi.org/10.17073/0368-0797-2019-9-737-742.
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Technological processes are multifactorial. The choice of the most significant of them for the correct analysis of the object of research is an important task. For such a ranking of factors, researchers usually rely on their own experience or the opinions of specialists in this field, assessing their consistency in terms of mathematical criteria. However, when developing a new process, this approach can not be used. In this case, experimental methods of selecting factors are preferable. But the cost, duration, and sometimes impossibility of using this method is obvious. In this paper we use a different approach. It was considered that thermodynamic modeling is an experiment, but only numerical. Therefore, you can apply it to the method of mathematical design of the experiment, allowing for one calculation to take into account the effect on the objective function of more than a dozen factors. The partial dependencies of the process indices obtained in this case make it possible, without setting up physical experiments, to weed out insignificant factors and leave strong ones, estimating them by the methods of mathematical statistics. Another important advantage of its application is the ability to evaluate the dynamics of changes in phase and elementary products of smelting, process feasibility according to convection and temperature conditions with the control of and mathematical criterion of the acquired data. The method also allows the process to be controlled by all the factors involved, which cannot be met in everyday modeling. For demonstration, this approach was applied during the development of the ferroborone production technology by carbothermic method using local raw materials. Thermodynamic modeling was performed using pre-selected factors. They were also used in physical simulation of the process in a high-temperature furnace. The experiment confirmed significance of the factors, which were chosen theoretically. The use of the planning method also reduced the number of numerical experiments in 25, and physical – in 125 times for predefined data.Using this approach, the authors have made it possible to compare the obtained data with the results of physical experiment to develop measures to approximate practical results to equilibrium ones with the use of strongly acting factor.
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Drachev, Roman, E. Deyneka, C. Rhodes, J. Schupp, and Tangali S. Sudarshan. "Fundamental Limitations of SiC PVT Growth Reactors with Cylindrical Heaters." Materials Science Forum 527-529 (October 2006): 15–20. http://dx.doi.org/10.4028/www.scientific.net/msf.527-529.15.
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The ability to set and accurately control the desired growth conditions is crucial in order to attain high quality bulk growth of Silicon Carbide (SiC), especially when the ingot size is large (> 2” in diameter by > 2” long). However, these two aspects of SiC PVT (Physical Vapor Transport) growth technology are severely limited in “conventional” SiC PVT growth reactors with single cylindrical heaters. To overcome such shortcomings, an “alternative” furnace design with two plane resistive heaters is proposed. In order to verify benefits of this design, numerical modeling and comparative procedures have been employed. Detailed comparative analysis revealed two fundamental disadvantages of the conventional furnace design, attributed to (a) – significantly higher in magnitude and spatially nonuniform distribution of the thermal stress that consequently deteriorates structural quality of the growing SiC boule, and (b) – inability to grow long (> 2”) monocrystalline ingots of SiC. Furthermore, the potential of the alternative furnace design to overcome fundamental limitations of the conventional design is also analyzed, with particular attention being paid to the processes of source material recrystallization.
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Askarova, A. S., S. A. Bolegenova, E. I. Lavrishcheva, and I. V. Loktionova. "The Modeling of Chemical Technological Process in the Fire Chambers." Eurasian Chemico-Technological Journal 4, no. 3 (2017): 147. http://dx.doi.org/10.18321/ectj527.
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<p>In this paper the results obtained by the method of numerical modeling of Ekibastuz coal burning in furnace on the example of fire chamber fixed on Aksy hydroelectric station are represented. Numerical experiment was carried out on the basis of three-dimensional equations of convective heat and mass transfer, taking into account the heat propagation, heat radiation, chemical reactions and multiphase structure of the medium. After the numerical experiment, the pictures of temperature distribution on the height of the chamber and concentration of CO, CO<sub>2</sub>, ash and coke distribution along the chamber were obtained. The results are represented graphically.</p>
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Litka, Rafał, and Sylwester Kalisz. "Numerical modelling of a stoker furnace operated under indirect co-firing of biomass." Chemical and Process Engineering 37, no. 2 (2016): 235–49. http://dx.doi.org/10.1515/cpe-2016-0019.
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Abstract The subject of the CFD analysis presented in this paper is the process of biomass indirect co-firing carried out in a system composed of a stoker-fired furnace coupled with a gasification reactor. The installation is characterised by its compact structure, which makes it possible to minimise heat losses to the environment and enhance the physical enthalpy of the oxidising agent – flue gases – having a favourable chemical composition with oxygen and water vapour. The test results provided tools for modelling of biomass thermal processing using a non-standard oxidiser in the form of flue gases. The obtained models were used to optimise the indirect co-combustion process to reduce emissions. An overall effect of co-combustion of gas from biomass gasification in the stoker furnace is the substantial reduction in NO emissions by about 22%.
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Sućeska, Muhamed, Zhi-Yue Liu, Sanja Matečić Mušanić, and Ivona Fiamengo. "Numerical modelling of sample–furnace thermal lag in dynamic mechanical analyser." Journal of Thermal Analysis and Calorimetry 100, no. 1 (2009): 337–45. http://dx.doi.org/10.1007/s10973-009-0447-z.
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dos Anjos, Patrick, Jorge Luís Coleti, Eduardo Junca, Felipe Fardin Grillo, and Marcelo Lucas Pereira Machado. "Artificial Neural Network-Based Non-Linear Modeling and Simulation of CaO-SiO2-Al2O3-MgO Blast Furnace Slag Viscosity." Minerals 14, no. 11 (2024): 1160. http://dx.doi.org/10.3390/min14111160.
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Blast furnace slags are formed by CaO-SiO2-Al2O3-MgO systems and have several physical characteristics, one of which is viscosity. Viscosity is an important variable for the operation and blast furnace performance. This work aimed to model viscosity through linear and non-linear models in order to obtain a model with precision and accuracy. The best model constructed was a non-linear model by artificial neural networks that presented 23 nodes in the first hidden layer and 24 nodes in the second hidden layer with 6 input variables and 1 output variable named ANN 23-24. ANN 23-24 obtained better statistical evaluations in relation to 11 different literature equations for predicting viscosity in CaO-SiO2-Al2O3-MgO systems. ANN 23-24 was also subjected to numerical simulations in order to demonstrate the validation of the non-linear model and presented applications such as viscosity prediction, calculation of the inflection point in the viscosity curve by temperature, the construction of ternary diagrams with viscosity data, and the construction of iso-viscosity curves.
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Prokhorov, V.B., S.L. Chernov, V.S. Kirichkov, and A.A. Kaverin. "Investigation of a Boiler's Furnace Aerodynamics with a Vortex Solid Fuel Combustion Scheme on Physical and Mathematical Models." Problemele Energeticii Regionale 1(36) (April 15, 2018): 1–11. https://doi.org/10.5281/zenodo.1217238.
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The important problem of developing the low-cost technologies that will be able to provide a deep decrease in the concentration of nitrogen oxides while maintaining fuel burn-up efficiency is considered. This paper presents the results of the aerodynamics study of the furnace of boiler TPP-210A on the base of the physical and mathematical models in the case when boiler retrofitting from liquid to solid slag removal with two to three times reduction of nitrogen oxide emissions andreplacing the vortex burners with direct-flow burners. The need for these studies is due to the fact that the direct-flow burners are "collective action" burners, and efficient fuel combustion can be provided only by the interaction of fuel jets, secondary and tertiary air jets in the furnace volume. The new scheme of air staged combustion in a system of vertical vortexes of opposite rotation with direct-flow burners and nozzles and direct injection of Kuznetsky lean coal dust was developed. In orderto test the functional ability and efficiency of the proposed combustion scheme, studies on the physical model of the boiler furnace and the mathematical model of the experimental furnace bench for the case of an isothermal fluid flow were carried out. Comparison showed an acceptable degree of coincidence of these results. In all studied regimes, pronounced vortices remain in both the vertical and horizontal planes, that indicates a high degree of mass exchange between jets and combustion products and the furnace aerodynamics stability to changes in regime factors.
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Vuigova, K. D., and M. G. Ziganshin. "Numerical modeling of hydrodynamics of spouted bed in solid fuel boiler." Safety and Reliability of Power Industry 17, no. 1 (2024): 19–27. http://dx.doi.org/10.24223/1999-5555-2024-17-1-19-27.
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The issues of numerical modeling of hydrodynamics of a spouted fuel bed in the furnace of a solid-fuel boiler are considered. At present, solid-fuel boilers are widely used in the power industry of the Russian Federation, with the share of coal-fired generation to remain significant in the projected terms. Therefore, the study of the efficiency of thermal and hydrodynamic processes that ensure the implementation of clean coal technologies is a relevant task both today and in the long term. The article presents the following main stages of numerical modelling of the hydrodynamics of the spouted bed: problem formulation with selection of boundary and initial conditions, methods of solving the Navier-Stokes and continuity equations for the air flow, Newton's equations and diffusion equations for particles. The k-omega turbulence model was used in the calculations that is described by means of two partial differential equations for the variables k (kinetic energy of turbulence) and omega (specific dissipation rate). A comparative analysis of environmental advantages and disadvantages of existing methods of combustion of low-grade coal in schemes with in-cycle gasification (ICG) is carried out. Advantages and difficulties of switching to structures with CFB in the spouted bed mode are shown. Numerical modeling of the cold spouted bed created by means of particle injection is performed, a set of initial settings and boundary conditions is presented, the adequacy of the obtained results is verified by hydrodynamic characteristics of the isothermal process. The obtained results allow us to proceed to the next stages with non-isothermal models, with heat exchange and combustion reactions in the spouted bed of coal taken into account. The following refinement of the physical model will allow to achieve more accurate and reliable results and to ensure their correct scaling.
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Coroas, Carlos, Iván Viéitez, Elena Martín, and Manuel Román. "Numerical Modeling for the Prediction of Microstructure and Mechanical Properties of Quenched Automotive Steel Pieces." Materials 16, no. 11 (2023): 4111. http://dx.doi.org/10.3390/ma16114111.
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In this work, we present an efficient numerical tool for the prediction of the final microstructure, mechanical properties, and distortions of automotive steel spindles subjected to quenching processes by immersion in liquid tanks. The complete model, which consists of a two-way coupled thermal–metallurgical model and a subsequent (one-way coupled) mechanical model, was numerically implemented using finite element methods. The thermal model includes a novel generalized solid-to-liquid heat transfer model that depends explicitly on the piece’s characteristic size, the physical properties of the quenching fluid, and quenching process parameters. The resulting numerical tool is experimentally validated by comparison with the final microstructure and hardness distributions obtained on automotive spindles subjected to two different industrial quenching processes: (i) a batch-type quenching process with a soaking air-furnace stage prior to the quenching, and (ii) a direct quenching process where the pieces are submerged directly in the liquid just after forging. The complete model retains accurately, at a reduced computational cost, the main features of the different heat transfer mechanisms, with deviations in the temperature evolution and final microstructure lower than 7.5% and 12%, respectively. In the framework of the increasing relevance of digital twins in industry, this model is a useful tool not only to predict the final properties of quenched industrial pieces but also to redesign and optimize the quenching process.
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Verdério Júnior, S. A., V. L. Scalon, S. R. Oliveira, E. Avallone, P. C. Mioralli, and D. M. Gonçalves. "EXPERIMENTAL METHODOLOGY FOR THE STUDY OF NATURAL CONVECTION ON FLAT AND CORRUGATED PLATES." Revista de Engenharia Térmica 20, no. 4 (2022): 36. http://dx.doi.org/10.5380/reterm.v20i4.84645.
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Natural convection is present in the most different Thermal Engineering systems, such as solar collectors, electric furnaces, electronic equipment cooling, lubrication, thermal comfort projects in buildings, etc. In the last decade, the number of research on natural convection heat transfer has increased considerably, especially in the areas of physical-numerical modeling and validation, experimental construction and efficiency optimization of thermal systems, and related technologies. This work presents an experimental methodology for studying natural convection on flat and corrugated plates. The design and construction stages of the experimental apparatus, data processing and analysis, physical-mathematical modeling and uncertainty analysis were extensively explored. The applications and extensions of the proposed methodology were discussed in the numerical-experimental validation of physical-numerical modeling methodologies, design and optimization of the experimental apparatus and also of measuring instruments and, finally, in sensitivity analysis studies to reduce the propagation of uncertainties. The limitations of the proposed methodology were discussed, pointing out suggestions for future work.
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Verdério Júnior, S. A., V. L. Scalon, S. R. Oliveira, E. Avallone, P. C. Mioralli, and D. M. Gonçalves. "EXPERIMENTAL METHODOLOGY FOR THE STUDY OF NATURAL CONVECTION ON FLAT AND CORRUGATED PLATES." Revista de Engenharia Térmica 20, no. 4 (2022): 36. http://dx.doi.org/10.5380/reterm.v20i4.84645.
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Natural convection is present in the most different Thermal Engineering systems, such as solar collectors, electric furnaces, electronic equipment cooling, lubrication, thermal comfort projects in buildings, etc. In the last decade, the number of research on natural convection heat transfer has increased considerably, especially in the areas of physical-numerical modeling and validation, experimental construction and efficiency optimization of thermal systems, and related technologies. This work presents an experimental methodology for studying natural convection on flat and corrugated plates. The design and construction stages of the experimental apparatus, data processing and analysis, physical-mathematical modeling and uncertainty analysis were extensively explored. The applications and extensions of the proposed methodology were discussed in the numerical-experimental validation of physical-numerical modeling methodologies, design and optimization of the experimental apparatus and also of measuring instruments and, finally, in sensitivity analysis studies to reduce the propagation of uncertainties. The limitations of the proposed methodology were discussed, pointing out suggestions for future work.
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Kislyakov, V. H., D. M. Togobitskaya, L. S. Molchanov, V. I. Yelisieiev, and Y. M. Likhachov. "Analysis of models of non-aggregate cast iron processing processes." Fundamental and applied problems of ferrous metallurgy 37 (2023): 184–200. http://dx.doi.org/10.52150/2522-9117-2023-37-184-200.
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The aim of this paper is to perform a generalized analysis of studies on modeling the processes of out-of-furnace treatment of cast iron. Mathematical models are classified according to the basic principles of modeling. A description of different models based on different principles is given, depending on their type and the differences between them. A more detailed analysis of some of the fundamental models and expressions obtained in their construction is carried out. An example of models built on experimental data is given. Neural network models consist of artificial neurons that are connected to each other by means of connecting weights, i.e., model parameters, in the form of layers. Neurons are a set of mathematical functions that modify the input data to obtain an estimate of the desired result. A large number of network parameters makes training a neural network a cumbersome computational process. The large number of network connection weights that need to be optimized when training such models usually requires a large amount of input data. The paper presents domestic achievements in the construction of mathematical models of the out-of-furnace iron treatment process. The principles of creating an integrated database that summarizes information on the parameters of various technologies for desulphurization of cast iron, including the developed system unit of the information retrieval system, are described; the concept of an expert system for making decisions on process control and selection of a rational technology for out-of-furnace desulphurization of cast iron is developed; the variant of the developed information and mathematical support of the expert system with the module for out-of-furnace treatment of cast iron with granular magnesium and coinjection of magnesium and lime is described; the results of the study are presented. The paper describes the models devoted to numerical and physical modeling of the phenomena that occur in the ladle during injection, as well as to the study of the regularities of the gas-powder flow.
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Skakov, Mazhyn, Viktor Baklanov, Assan Akaev, et al. "On the Possibility of Forming a Corium Pool by Induction Heating in a Melt Trap of the Lava-B Facility." Applied Sciences 13, no. 4 (2023): 2480. http://dx.doi.org/10.3390/app13042480.
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This paper presents the results of computational and physical studies on the production of corium and its retention in an MR’s melt trap of the Lava-B facility. A feature of the Lava-B facility used in the IAE NNC RK to study the processes occurring during a severe accident at a nuclear reactor, is the separation of the stages of the reactor core corium formation and its interaction with structural materials. The melting of materials takes place in an induction furnace with a hot crucible, after which it moves to a melt receiver (MR) in which the test object is located. In the case of studies of processes occurring outside the reactor vessel, this is a special trap, which is placed in the inductor to simulate decay heat. However, based on the conservative computational estimates, it was found that the inductor power in the MR can be sufficient to directly produce, melt, and, subsequently, maintain the corium in the liquid phase. In this regard, in order to optimize the experiments under controlled conditions, the authors came up with the idea to experimentally test the possibility of producing corium by induction heating directly in the MR’s melt trap. In addition, according to the authors, this method would obviate the problem of corium contact with the carbon environment of the melting furnace of the Lava-B facility. Previously, burden heating simulating corium was modeled on the computer using available parameters of the MR’s induction heater. Based on the numerical experiment, the conditions for physical modeling of the corium production in the MR’s melt trap were established. An analysis of the physical modeling showed that during the burden heating in the melt trap, its metal components became liquid, thus, forming a melt pool. However, in terms of this design of the trap, there were problems associated with the complete melting of all corium components, as well as with the integrity of the experimental device when forming the corium pool and during the actual physical modeling.
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Cwudziński, Adam, Jacek Pieprzyca, and Tomasz Merder. "Numerical and Physical Modeling of Liquid Steel Asymmetric Behavior during Non-Isothermal Conditions in a Two-Strand Slab Tundish—“Butterfly Effect”." Materials 16, no. 21 (2023): 6920. http://dx.doi.org/10.3390/ma16216920.
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This paper presents the results of studies on the occurrence of transient disturbances in the hydrodynamic system of a tundish feeding area and their effect on the casting process. In addition, the effect of changes in the level of superheating of the molten steel fed to the tundish on the evolution of the hydrodynamic system was analyzed. The studies were conducted with the use of a physical model of the tundish and a numerical model, representing the industrial conditions of the process of the continuous casting of steel. When a tundish is fed through a modified ladle shroud that slows down the momentum of the stream, this creates favorable conditions for the emergence of asymmetrical flow within the working tundish volume. The higher the degree of molten steel reheating in the ladle furnace, the stronger the evolution of the hydrodynamic structures in the tundish during the casting process.
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Gil, Andrey V., Kirill I. Maltsev, Nikita V. Abramov, Alexander S. Zavorin, and Alexander V. Starchenko. "Impact of boiler unit load changes on furnace processes." Bulletin of the Tomsk Polytechnic University Geo Assets Engineering 335, no. 10 (2024): 32–42. http://dx.doi.org/10.18799/24131830/2024/10/4778.
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Relevance. The need to assess the stability of combustion, thermal stress and nitrogen oxides (NOx) emission during load reduction of a steam boiler. Since renewable energy sources and nuclear power plants will receive great attention in the future, coal-fired thermal power plants are to operate at reduced loads, so it is important to investigate the reliability of operation and environmental parameters of the boiler unit in case of load adjustment. Aim. To investigate pulverized coal fuel burnout, temperature parameters and NOx emission at 50 % reduction of boiler unit load in the base configuration and taking into account installation of tertiary blast nozzles. Objects. Furnace chamber of a natural circulation boiler unit with steam capacity of 220 t/h in the baseline layout and with tertiary air nozzles. Methods. The package of application programs FIRE-3D for numerical study was applied. Combustion of pulverized coal fuel is a complex physical and chemical process, therefore the interaction of gas flow and solid particles was modeled using Eulerian and Lagrangian schemes, respectively. In the gas phase, the combustion of volatiles and CO with further combustion of carbon residue are modeled. NOx emission is modeled using post-treatment models including formation of fast, fuel and thermal nitrogen oxides. Results. Temperature fields, flow characteristics, NOx emissions for different loads of the furnace chamber of the boiler unit with steam capacity of 220 t/hour are obtained on the basics of numerical modeling. The authors have obtained quantitative estimations of furnace environment parameters corresponding to several levels of boiler load reduction up to 50% of the nominal one. Installation of four tertiary blast nozzles allows reducing NOx emissions by 12.75% at theoretically required amount of air in burner devices (α=1.0).
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Bublik, Sergey, Jan Erik Olsen, Varun Loomba, Quinn Gareth Reynolds, and Kristian Etienne Einarsrud. "A Review of Ferroalloy Tapping Models." Metallurgical and Materials Transactions B 52, no. 4 (2021): 2038–47. http://dx.doi.org/10.1007/s11663-021-02134-5.
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AbstractTapping is an important furnace operation in the ferroalloy industry and poses a number of complex and coupled challenges of both practical and economical importance. Owing to the hazardous high-temperature conditions surrounding the tap hole, the application of various modeling techniques allows for development and acquisition of both scientific and engineering knowledge of the process through physical or numerical proxies. In this review, earlier work on modeling of ferroalloy tapping is summarized and main principles of the tapping process and multiphase interaction of slag and metal are discussed and summarized. The main focus is on drainage of slag and alloys, but some attention will also be given to metal loss, metal overflow and health, safety and environment. Our review shows that although considerable progress has been made in computational capability over the last decades, However, it is clear that research and development in the field of ferroalloy furnace tapping remains at a relatively nascent stage. The most progress up to date has happened in the area of so called reduced-order models. Such models are robust and simple, and may be easily fitted to process data from a particular operation in order to develop tailored solutions. Such models are more easily combined with software and instruments, ultimately enabling improved automation, process control and ultimately improved tapping consistency.
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Batrakov, P. A., E. A. Ryzhnikova, and A. A. Batrakova. "Numerical modeling of the processes of heating, evaporation and combustion of emulsified fuel." Safety and Reliability of Power Industry 17, no. 4 (2025): 289–98. https://doi.org/10.24223/1999-5555-2024-17-4-289-298.
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The issue of mixing fuel oil with water, i. e. emulsification, is considered. Emulsified fuel of the “water-fuel oil” type is a promising alternative fuel, as it causes water to boil at high temperatures, which can improve the atomization of the fuel spray. The process of heating and evaporation of a droplet of emulsified fuel depends on the diffusion and coalescence of the smallest water particles in the fuel oil, which occur during heating. The article presents a model that accounts for the process of water diffusion in droplets of emulsified fuels, as well as the physical properties of the entire medium. The model incorporates these important physical phenomena and offers an effective method for calculating the ratio of emulsion components. It is designed to describe the heating and evaporation of droplets of emulsified fuel, such as “water-fuel oil”. The process of water coalescence is simplified by the fact that dispersed water droplets instantly combine into a single water subdroplet in the center of the fuel oil droplet. During the calculations, the proportions of each component are taken into account; in addition to the combustion of the carbon content of the fuel oil, it is necessary to consider the heat release of water vapor, the release of hydrogen, the dissociation of water and the thermal effect of hydrogen combustion. These processes occur in the same proportions as in the water-fuel oil emulsion. To address the tasks at hand, the ANSYS CFX module was selected, which allows for the simulation of chemical reactions and combustion processes associated with liquid flow. This will enable a detailed study of the phenomena occurring and help determine the optimal parameters of the water-fuel oil emulsion, thereby increasing operational efficiency. Based on the proposed model, the combustion process in the furnace volume as a function from the water content in the emulsified fuel was analyzed.
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Asad, Amjad, Katrin Bauer, Kinnor Chattopadhyay, and Rüdiger Schwarze. "Numerical and Experimental Modeling of the Recirculating Melt Flow Inside an Induction Crucible Furnace." Metallurgical and Materials Transactions B 49, no. 3 (2018): 1378–87. http://dx.doi.org/10.1007/s11663-018-1200-4.
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Kovalov, A., Y. Otrosh, V. Tomenko, and V. Slovinskyi. "EVALUATION OF FIRE RESISTANCE OF FIRE PROTECTED STEEL STRUCTURES BY CALCULATION AND EXPERIMENTAL METHOD." Mechanics And Mathematical Methods 3, no. 2 (2021): 29–39. http://dx.doi.org/10.31650/2618-0650-2021-3-2-29-39.
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Based on the developed geometric, physical, computer and finite element model, the fire resistance of fire-resistant steel structures was evaluated by calculation and experimental method. The adequacy of the developed computational-experimental method for assessing the fire resistance of fire-resistant steel structures in assessing the fire resistance of a fire-resistant I-beam steel column was verified. The results of tests for fire resistance of steel columns with fire-retardant coating at standard temperature of the fire without the load applied to them (temperature in the furnace, temperature in certain places on the surface of fire-retardant steel columns, the behavior of the investigated fire-retardant coating). The analysis of tests on fire resistance of fire-resistant steel columns exposed to fire at standard temperature (temperature in the furnace, temperature in places of measurement of temperature on a surface of columns, behavior of a fire-retardant covering) is carried out. A computer model of the «steel column – reactive flame retardant coating» system has been built for numerical simulation of non-stationary heating of such a system. Simulation of non-stationary heating of the system «steel column – fire-retardant coating» in the software package FRIEND with the specified parameters (geometric model, thermal effects, initial and boundary conditions, properties of system materials). The reliability of the results of numerical modeling with real experimental data on the duration of fire exposure at the standard temperature of the fire to reach the critical temperature of steel. Based on the comparison of experimental results and numerical simulations, a conclusion is made about the adequacy of the developed model to the real processes that occur when heating fire-retardant steel columns without applying a load under fire conditions at standard fire temperature. The efficiency of the proposed calculation and experimental method for assessing the fire resistance of fire-resistant steel structures has been confirmed.
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Raja, Ramiz, Supriya Pal, and Arindam Karmakar. "IN-SITU REMEDIATION OF HEAVY METAL CONTAMINATED SITES THROUGH MECHANICAL STABILIZATION USING INDUSTRIAL WASTE PRODUCTS." Journal of Environmental Engineering and Landscape Management 30, no. 2 (2022): 301–7. http://dx.doi.org/10.3846/jeelm.2022.17077.
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The present study aimed to assess the stabilization performance of fly ash, blast furnace slag and quick lime for heavy metals in contaminated soil at a landfill site at Kolkata, West Bengal, India. The physical properties and strength parameters of the contaminated soil substantially increased after additives application. Moreover, the heavy metal concentrations in the leachate of the polluted soil were found almost nil after optimum blending of the additives mechanically with the soil and post-curing for 7 days. The numerical modeling studies were also carried out using PLAXISTM 3D software to ascertain the improvement of safety factor and deformation caused at the foundation level of an embankment constructed on such stabilized soil. The vertical displacement of the embankment founded on stabilized soil reduced from 194.3 to 136.3 mm and the safety factor of the embankment slope (1 V:1.5 H) increased from 2.5 to 3.2 under drained condition.
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Chen, Chunming, and Yogesh Jaluria. "Modeling of Radiation Heat Transfer in the Drawing of an Optical Fiber With Multilayer Structure." Journal of Heat Transfer 129, no. 3 (2006): 342–52. http://dx.doi.org/10.1115/1.2430723.
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A numerical model is developed to study the radiative heat transfer in a furnace for optical fiber drawing with a core-cladding structure in the fiber. The focus is on the effect of the difference in composition and thus the radiation properties in the two regions on radiative transport. The zonal method is applied to calculate the radiative heat transfer within the neck-down region of the preform. The radiative heat transfer between the preform and the furnace is computed by an enclosure analysis. A parallel computational scheme for determining the direct exchange areas is also studied. The radiation model is verified by comparisons with benchmark problems. Numerical results for a pure silica preform, a GeO2-doped silica core with a pure silica cladding preform, and a pure silica core with a B2O3-doped silica cladding preform are presented. Radiation properties for these are obtained from the literatures and a three-band model is developed to represent the values. It is found that radiative heat flux on the surface of the preform is strongly affected by the differences in the absorption coefficient due to doping. However, changes of about 1% in the refractive index have only a small effect on radiative heat transfer. The basic approach is outlined in order to form the basis for simulating optical fiber drawing processes, which typically involve fibers and preforms with a core and a cladding. Furthermore, the approach can apply to estimate the multi-layer fiber drawing, which is of interest in the fabrication of specialty fibers that have been finding uses in a variety of practical applications. The model can be extended to other similar processes, which involve multiple regions with different radiation properties. The main interest in this study is on the approximate representation of radiation properties and on the modeling of the transport process.
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Chen, Chunming, and Yogesh Jaluria. "Numerical Simulation of Transport in Optical Fiber Drawing with Core–Cladding Structure." Journal of Heat Transfer 129, no. 4 (2006): 559–67. http://dx.doi.org/10.1115/1.2709968.
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Optical fibers are typically drawn from silica preforms, which usually consist of two concentric cylinders called the core and the cladding, heated in a high-temperature furnace. For optical communication purposes, the core always has a higher refractive index than the cladding to obtain total internal reflection. In order to investigate the effect of this core–cladding structure on optical fiber drawing, a numerical model has been developed in this work. Axisymmetric flows of a double-layer glass and aiding purge gas in a concentric cylindrical furnace are considered. The thermal and momentum transport in both glass layers and gas are coupled at the interface boundaries. The neck-down profile is generated using an iterative numerical scheme. The zonal method is applied to model the radiation transfer in the glass preform. The gas is taken as nonparticipating. Coordinate transformations are used to convert the resulting complex domains into cylindrical regions. The stream function, vorticity, and energy equations for the core, the cladding, and the purge gas are solved by finite difference methods, using a false transient approach coupled with the alternating direction implicit method. A second-order differencing scheme is used for discretization. The numerical results are validated by comparing with results available in the literature. The effects of changes in the refractive index and absorption coefficient due to doping on fiber drawing are investigated. This problem has received very little attention in the literature, particularly with respect to modeling, and this paper presents an initial study of the underlying transport.
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Huang, Can, Ulrike Hecht, and Andreas Bührig-Polaczek. "Numerical Modeling of Melting and Columnar Solidification with Convection in a Gradient Zone Furnace in a Centrifuge." Metallurgical and Materials Transactions B 51, no. 5 (2020): 2252–67. http://dx.doi.org/10.1007/s11663-020-01914-9.
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Ghannam, Boutros, Maroun Nemer, Khalil El Khoury, and Walter Yuen. "Experimental Validation of the Multiple Absorption Coefficient Zonal Method (MACZM) in a Dynamic Modeling of a Steel Reheating Furnace." Numerical Heat Transfer, Part A: Applications 58, no. 7 (2010): 545–63. http://dx.doi.org/10.1080/10407782.2010.511989.
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Soroka, B. S. "WET BURNING – THE MODERN TREND IN ENVIRONMENTAL BENIGN FUEL COMBUSTION AND IN SOLUTION TO THE PROBLEM OF SUSTAINABLE DEVELOPMENT OF THE POWER GENERATION." Alternative Energy and Ecology (ISJAEE), no. 25-30 (December 7, 2018): 96–117. http://dx.doi.org/10.15518/isjaee.2018.25-30.096-117.
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The article considers the role and place of water and water vapor in combustion processes with the purpose of reduction the effluents of nitrogen oxides and carbon oxide. We have carried out the complex of theoretical and computational researches on reduction of harmful nitrogen and carbon oxides by gas fuel combustion in dependence on humidity of atmospheric air by two approaches: CFD modeling with attraction of DRM 19 chemical kinetics mechanism of combustion for 19 components along with Bowman’s mechanism used as “postprocessor” to determine the [NO] concentration; different thermodynamic models of predicting the nitrogen oxides NO formation. The numerical simulation of the transport processes for momentum, mass and heat being solved simultaneously in the united equations’ system with the chemical kinetics equations in frame of GRI methane combustion mechanism and NO formation calculated afterwards as “postprocessor” allow calculating the absolute actual [CO] and [NO] concentrations in dependence on combustion operative conditions and on design of furnace facilities. Prediction in frame of thermodynamic equilibrium state for combustion products ensures only evaluation of the relative value of [NO] concentration by wet combustion the gas with humid air regarding that in case of dry air – oxidant. We have developed the methodology and have revealed the results of numerical simulation of impact of the relative humidity of atmospheric air on harmful gases formation. Range of relative air humidity under calculations of atmospheric air under impact on [NO] and [CO] concentrations at the furnace chamber exit makes φ = 0 – 100%. The results of CFD modeling have been verified both by author’s experimental data and due comparing with the trends stated in world literature. We have carried out the complex of the experimental investigations regarding atmospheric air humidification impact on flame structure and environmental characteristics at natural gas combustion with premixed flame formation in open air. The article also proposes the methodology for evaluation of the nitrogen oxides formation in dependence on moisture content of burning mixture. The results of measurements have been used for verification the calculation data. Coincidence of relative change the NO (NOx) yield due humidification the combustion air revealed by means of CFD prediction has confirmed the qualitative and the quantitative correspondence of physical and chemical kinetics mechanisms and the CFD modeling procedures with the processes to be studied. A sharp, more than an order of reduction in NO emissions and simultaneously approximately a two-fold decrease in the CO concentration during combustion of the methane-air mixture under conditions of humidification of the combustion air to a saturation state at a temperature of 325 K.
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Zhang, H., L. L. Zheng, V. Prasad, and D. J. Larson. "Local and Global Simulations of Bridgman and Liquid-Encapsulated Czochralski Crystal Growth." Journal of Heat Transfer 120, no. 4 (1998): 865–73. http://dx.doi.org/10.1115/1.2825905.
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A curvilinear finite volume-based numerical methodology has been developed that can be effectively used for simulation of the Bridgman and Czochralski (Cz) crystal growth processes. New features of grid generation have been devised and added to the original formulation (Zhang et al., 1995, 1996) to make it suitable for global modeling. The numerical model can account for convection in both the melt and the gas phases, convection/radiation in the furnace, and conduction in all solid components. Results for Bridgman growth show that the flow pattern and interface shape strongly depend on thermal conductivities of the crystal, melt, and ampoule materials. Transient simulations have been performed for the growth of Bismuth crystal in a Bridgman-Stockbarger system and the growth of GaAs crystal using liquid-encapsulated Czochralski (LEC) technique. This is the first time that a global high-pressure LEC model is able to account for convective flows and heat transfer and predict the interface shape and its dynamics.
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Nestovito, Gianluca, and Francesco Messina. "Fly Ash/Blast Furnace Slag Geopolymer Repair System as a Sustainable Solution for the Maintenance of an Existing Bridge: Materials Design and Influence on Shear Capacity under Seismic Conditions." Advanced Materials Research 1105 (May 2015): 346–54. http://dx.doi.org/10.4028/www.scientific.net/amr.1105.346.
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This study deals with the paramount topic of sustainable and durable composite materials for repair of damaged existing bridge. Reinforced concrete is the most used composite system in structural design but, across several decades, it has shown some fragilities related to chemico-physical resistance. Durability improvement by means of innovative repair systems represent, therefore, a crucial economic parameter allowing a highly significant reduction of maintenance cost. A maintenance scenario is here simulated, considering a repair composite realized with a binary geopolymer binder, obtained by activating two industrial by-products, namely coal fly ash and blast furnace slag, in alkaline environment. Physico-mechanical characterization of geopolymer concrete is also performed, showing the suitability of this innovative repair system. In order to investigate the effectiveness of geopolymer, a 3D finite element model is developed in Sap2000 to represent the complex behavior of a full-scale Italian highway bridge. Numerical simulations are conducted by modeling the geopolymer concrete as a jacketing applied to the damaged piers. Results reveal that the designed repair system could increase shear capacity of bridge piers under seismic conditions, not neglecting the low cost of raw materials and the high durability of geopolymers.
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Merder, Tomasz, Piotr Warzecha, Jacek Pieprzyca, Marek Warzecha, Robert Wende, and Artur Hutny. "Model Investigation of Argon Injection into Liquid Steel at Ladle Furnace Station with Using of Innovative Module." Materials 16, no. 24 (2023): 7698. http://dx.doi.org/10.3390/ma16247698.
Full textAbstract:
High-quality steels are defined primarily by a small quantity of non-metallic inclusions and a high degree of chemical homogenisation. The ladle furnace (LF) is the most important metallurgical unit in which the quantity of non-metallic inclusions can be significantly reduced while ensuring metal chemical homogenisation. It is achieved largely due to appropriate controlling and the use of increasingly developed inert gas purging techniques. Various types of porous plugs (channel or radial type) are used in the metallurgical ladles. In aggregate units of intermediate-ladle type, various types of channel plugs and/or gas curtains are successfully used. In the research presented herein, a new and innovative module for inert gas injection into liquid steel for deep refining was tested. The presented research relates to the innovative module using to replace the standard porous plug in the steelmaking ladle on the outside-furnace (LF) processing station. Hybrid modelling methods (numerical and physical modelling) were used to carry out research. Module using causes significantly faster alloy additive dispersion in ladle volume compared with the standard solution (the standard porous plug). Furthermore, the obtained flowing structure positively affects liquid steel refining and mixing processes after alloy additive addition. A new technological solution, i.e., gas-injection module—differs from the traditional porous plugs currently used in the steel mills in terms of geometric parameters, external and internal structure, and what is most importantly, terms of the active surface area—shall be understood in as the surface area wherein slots occur.
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Rokhman, B. B., and A. A. Shraiber. "Mathematical modeling of the aerodynamics and physicochemical processes in the freeboard zone of a circulating fluidized bed furnace. 3. Boundary conditions. Some numerical results." Journal of Engineering Physics and Thermophysics 66, no. 6 (1994): 607–14. http://dx.doi.org/10.1007/bf00867958.
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Askarova A.S., Bolegenova S.A., Safarik P., et al. "MODERN COMPUTING EXPERIMENTS ON PULVERIZED COAL COMBUSTION PROCESSES IN BOILER FURNACES." PHYSICO-MATHEMATICAL SERIES, no. 6 (December 15, 2018): 5–14. http://dx.doi.org/10.32014/2018.2518-1726.11.
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The aim of the work is to create new computer technologies for 3D modeling of heat and mass transfer processes in high-temperature physico-chemical-reactive environments that will allow to determine the aerodynamics of the flow, heat and mass transfer characteristics of technological processes occurring in the combustion chambers in the operating coal TPP RK. The novelty of the research lies in the use of the latest information technologies of 3D modeling, which will allow project participants to obtain new data on the complex processes of heat and mass transfer during the burning of pulverized coal in real combustion chambers operating in the CHP of RK. Numerical simulation, including thermodynamic, kinetic and three-dimensional computer simulation of heat and mass transfer processes when burning low-grade fuel, will allow finding optimal conditions for setting adequate physical, mathematical and chemical models of the technological process of combustion, as well as conduct a comprehensive study and thereby develop ways to optimize the process of ignition, gasification and burning high ash coals. The proposed methods of computer simulation are new and technically feasible when burning all types of coal used in pulverized coal-fired power plants around the world. The developed technologies will allow replacing or eliminating the conduct of expensive and labor-consuming natural experiments on coal-fired power plants.
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Reynolds, Q. G., B. Bowman, MW Erwee, et al. "Plasma soup for the pyrometallurgist's soul." Journal of the Southern African Institute of Mining and Metallurgy 125, no. 3 (2025): 129–44. https://doi.org/10.17159/2411-9717/758/2025.
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Understanding the behaviour of plasma arcs is an important part of the design and operation of direct current electric arc furnace smelting processes, which are used in the industrial production of many metallurgical commodities. In recent years numerical and computational modelling techniques have begun to illuminate the complexity of arc behaviour and how it is deeply connected to the thermodynamic and physical properties of the arc plasma. Plasma properties may be estimated from first principles using statistical mechanics methods, but this requires as input some knowledge of the composition of the gas phase that occurs over the process during smelting. In this paper the authors describe a workflow using thermochemistry software to predict the expected gas phase composition through a given process, followed by plasma property calculations using an open-source software tool that has been in development for several years. This tool, 'minplascalc' has been in development for several years and is also described in detail here. The workflow is then applied to the calculation of plasma properties of interest for a variety of historical and current pyrometallurgical processes, and the results are compared. The plasma property data are published in an open-access database for general use.