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Number of results: 20
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Abstract

The Exodus method is applied to solve Fourier-Kirchoff's equation in heat transfer problems for flat plate solar collectors. Probabilistic models have been presented for the steady and non-steady conditions. The mathematical description of these models has been derived on the basis of the analogy between the conduction difference equation and the equation describing walking particle movement. The results of computations performed by the Exodus method have been compared to the results obtained by the Equivalent Thermal Network and the Finite Difference methods. The Exodus procedure allows the influence of changeable weather and operating conditions to be considered in calculations.
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Authors and Affiliations

Alicja Siuta-Olcha
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Abstract

Because the heat release of plutonium material, the composite structure is heated and the stress and strain of the composite structure will increase, which will affect the thermodynamic properties of the structure. The thermodynamic analysis of complex structures, which are composed of concentric structures of plutonium, beryllium, tungsten, explosives, and steel, was carried out. The results showed that when the structure is spherical, the temperature is higher than that of the ellipsoid structure. Stress of the elliptical structure is greater than the spherical structure. This study showed that the more flat the shell is, the greater the stress concentration point occurs at the long axis, and the maximum stress occurs at the beryllium layer. These conclusions provide theoretical support for the plutonium composite component testing.

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Authors and Affiliations

Gou Zhenzhi
He Bin
Yang Guilin
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Abstract

The paper evaluates two approaches of numerical modelling of solidification of continuously cast steel billets by finite element method, namely by the numerical modelling under the Steady-State Thermal Conditions, and by the numerical modelling with the Traveling Boundary Conditions. In the paper, the 3D drawing of the geometry, the preparation of computational mesh, the definition of boundary conditions and also the definition of thermo-physical properties of materials in relation to the expected results are discussed. The effect of thermo-physical properties on the computation of central porosity in billet is also mentioned. In conclusion, the advantages and disadvantages of two described approaches are listed and the direction of the next research in the prediction of temperature field in continuously cast billets is also outlined.
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Authors and Affiliations

M. Tkadlečková
K. Michalek
M. Strouhalová
M. Saternus
T. Merder
J. Pieprzyca
J. Sviželová
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Abstract

The paper analysed the influence of current frequency on the thermal field of the insulated busbar. Its physical model consist of two hollow cylinders and a solid cylinder with different material properties. In turn, the mathematical model is a system of heat conduction equations with the appropriate set of the boundary, initial and continuity conditions. The problem was solved using the modified Green’s method. As a result, the following characteristics and parameters of the busbar were determined as a functions of frequency: heating curves, local time constants, steady-state current ratings, and stationary temperature profiles. The results were positively verified by finite element method.

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Authors and Affiliations

J. Gołębiowski
M. Zaręba
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Abstract

The paper presents the analysis of temperature fields, phase transformations, strains and stresses in a cuboidal element made from S235 steel, surfaced with multipass GMA (Gas Metal Arc) method. The temperature field is described assuming a dualdistribution heat source model and summing up the temperature fields induced by the padded weld and by the electric arc. Dependence of stresses on strains is assumed on the basis of tensile curves of particular structures, taking into account the influence of temperature. The calculations were carried out on the example of five welds in the middle of the plate made of S235 steel. The simulation results are illustrated in graphs of thermal cycles, volume shares of structural components and stresses at the selected points of cross-section, and the temperature and strain distributions in the whole cross section.

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Authors and Affiliations

J. Winczek
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Abstract

An electric turnout heating (ETH) system is an essential technical and economic issue. Uninterrupted operation of the turnouts is crucial to maintaining railway transport safety. The classic heating system is characterized by high energy consumption. The usage of it is extremely expensive, so the need to optimize the current system becomes more and more critical. At the same time, the progress in the contactless heating method has become a promising alternative. The paper presents the results of tests performed for electric turnout heating systems for two types of heaters. In the first place, the analysis of heat distribution was performed using the ANSYS Fluent v.16. The temperature fields in the turnout models filled with a model of semi-melting snow were analyzed. Thanks to cooperation with the Railway Institute inWarsaw the second stage of the research was possible to be completed.

In this part, the models were implemented in the real world using the 49E1 railway turnout. The numerical solutions were validated by the experiments. The verification showed a high level of agreement among the results. The obtained results indicate the need for further tests of heating systems, to validate an optimal method of turnout heating. It was found that in the classic ETH, the working space area consumes a tremendous amount of energy. To ensure a higher efficiency of the heating process, the contactless heater is proposed as an alternative.

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Authors and Affiliations

Mateusz Flis
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Abstract

The paper has investigated the effect of wind speed on selected thermal characteristics of the contemporary ACCR line. As wind speed functions, heating curves, stationary temperature profiles, steady-state current ratings and thermal time constants, have been determined. The composite core (Al–Al2O3) and the Al–Zr alloy braid were modeled as porous solids. As a result, the physical model is composed of a solid cylinder and a hollow cylinder with different material parameters of the above-mentioned elements. The mathematical model was formulated as the boundary-initial problem of the parabolic heat equation. The problem was solved by the state-superposition of and variable-separation method. On this basis, a computer program was developed in the Mathematica 10.4 environment and the velocity characteristics sought for were plotted. The results obtained analytically were positively verified by the finite-element method in the NISA v.16 environment. The physical interpretation of the determined characteristics has been given.
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Authors and Affiliations

Marek Zaręba
1
Jerzy Gołębiowski
1

  1. Faculty of Electrical Engineering, Bialystok University of Technology, ul. Wiejska 45D, 15-351 Białystok, Poland
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Abstract

The current passed by the stator coil of the permanent magnet synchronous motor (PMSM) provides rotating magnetic field, and the number of turns will directly affect the performance of PMSM. In order to analyze its influence on the PMSM performance, a 3 kW, 1500 r/min PMSM is taken as an example, and the 2D transient electromagnetic field model is established. The correctness of the model is verified by comparing the experimental data and calculated data. Firstly, the finite element method (FEM) is used to calculate the electromagnetic field of the PMSM. The performance parameters of the PMSM are obtained. On this basis, the influence of the number of turns on PMSM performance is quantitatively analyzed, including current, no-load back electromotive force (EMF), overload capacity and torque. In addition, the influence of the number of turns on eddy current loss is further studied, and its variation rule is obtained, and the variation mechanism of eddy current loss is revealed. Finally, the temperature field of the PMSM is analyzed by the coupling method of electromagnetic field and temperature field, and the temperature rise law of PMSM is obtained. The analysis of this paper provides reference and practical value for the optimization design of PMSM.

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Authors and Affiliations

H. Qiu
Y. Zhang
C. Yang
R. Yi
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Abstract

Postharvest processing of grain is an important step in the overall grain production process. It makes possible not only quantitative and qualitative preservation of the harvest, but also ensures maximum profit from its sale at the most favorable market conditions. Convective heat treatment (drying, cooling) guarantees commercial harvest conservation, prevents its loss, and in some cases improves the quality of the finished product. The necessity of intensification and automation of technological processes of postharvest grain processing requires the development of methods of mathematical modeling of energy-intensive processes of convective heat treatment. The determination and substantiation of optimum modes and parameters of equipment operation to ensure the preservation of grain quality is possible only when applying mathematical modeling techniques. In this work, a mathematical model of particulate material drying is presented through a system of differential equations in partial derivatives of which the variable in time and space relationship between heat and mass transfer processes in the material and a drying agent is reflected. The aim of the research was to determine the dynamics of the interrelated fields of unsteady temperature and moisture content of the material and the drying agent on the basis of mathematical models of heat and mass transfer in the layer of particulate material in convective heat approach or heat retraction. The implementation of the mathematical model proposed in the standard mathematical set allows analyzing efficiency of machines and equipment for the convective heat treatment of particulate agricultural materials in a dense layer, according the determinant technological parameters and operating modes.
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Authors and Affiliations

Boris Kotov
Roman Kalinichenko
Anatoliy Spirin
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Abstract

Induction surface hardening means the hardening of a thin zone of the material only, while its core remains soft. The paper deals with the modelling of the Consecutive Dual Frequency Induction Hardening (CDFIH) of gear wheels and its validation. For gear wheels with modulus m smaller than 6 mm a contour profile of hardness distribution could be obtained. The investigated gear wheel is heated first by a medium frequency inductor to the temperature approximately equal to the modified lower temperature Ac1m. It means beginning of the austenite transformation. Then the gear wheel is heated by the high frequency inductor to the hardening temperature making it possible to complete the austenite transformation and immediately cooled. In order to design the process it is necessary to identify modified critical temperatures and to obtain expected temperature distribution within the whole tooth.

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Authors and Affiliations

Jerzy Barglik
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Abstract

In order to research the losses and heat of damper bars thoroughly, a multislice moving electromagnetic field-circuit coupling FE model of tubular hydro-generator and a 3D temperature field FE model of the rotor are built respectively. The factors such as rotor motion and non-linearity of the time-varying electromagnetic field, the stator slots skew, the anisotropic heat conduction of the rotor core lamination and different heat dissipation conditions on the windward and lee side of the poles are considered. Furthermore, according to the different operating conditions, different rotor structures and materials, compositive calculations about the losses and temperatures of the damper bars of a 36 MW generator are carried out, and the data are compared with the test. The results show that the computation precision is satisfied and the generator design is reasonable.

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Authors and Affiliations

Yong Liao
Zhen-Nan Fan
Li Han
Li-Dan Xie
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Abstract

To study the principle of loss and heat at the end region of large 4-poles nuclear power turbine generator, 3D transient electromagnetic field and 3D steady temperature field finite element (FE) models of the end region are established respectively. Considering the factors such as rotor motion, core non-linearity and time-varying of electromagnetic field, the anisotropic heat conductivity and different heat dissipation conditions of stator end region, a 50 Hz, 1150 MW, 4-poles nuclear power turbine generator is investigated. The loss and heat at the generator end region are calculated respectively at no-load and rated-load, and the calculation results are compared with the test data. The result shows that the calculation model is accurate and the generator design is suitable. The method is valuable for the research of loss and heat at the end region of large 4-poles nuclear power turbine generator and the improvement of the generator’s operation stability. The method has been applied successfully for the design of the larger nuclear power turbine generators.

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Authors and Affiliations

Guang-Hou Zhou
Li Han
Zhen-Nan Fan
Yong Liao
Song Huang
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Abstract

Cu–4.7 wt. % Sn alloy wire with Ø10 mm was prepared by two-phase zone continuous casting technology, and the temperature field, heat

and fluid flow were investigated by the numerical simulated method. As the melting temperature, mold temperature, continuous casting

speed and cooling water temperature is 1200 °C, 1040 °C, 20 mm/min and 18 °C, respectively, the alloy temperature in the mold is in the

range of 720 °C–1081 °C, and the solid/liquid interface is in the mold. In the center of the mold, the heat flow direction is vertically

downward. At the upper wall of the mold, the heat flow direction is obliquely downward and deflects toward the mold, and at the lower

wall of the mold, the heat flow deflects toward the alloy. There is a complex circular flow in the mold. Liquid alloy flows downward along

the wall of the mold and flows upward in the center.

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Authors and Affiliations

J. Luo
X. Liu
X. Wang
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Abstract

In the paper the modelling of thermo-mechanical effects in the process of friction welding of corundum ceramics and aluminium is presented. The modelling is performed by means of finite element method. The corundum ceramics contains 97% of Al2O3. The mechanical and temperature fields are considered as coupled fields. Simulation of loading of the elements bonded with the heat flux from friction heat on the contact surface is also shown. The heat flux was modified in the consecutive time increments of numerical solutions by changeable pressure on contact surface. Time depending temperature distribution in the bonded elements is also determined. The temperature distribution on the periphery of the cylindrical surfaces of the ceramics and Al was compared to the temperature measurements done with a thermovision camera. The results of the simulation were compared to those obtained from the tests performed by means of a friction welding machine

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Authors and Affiliations

Z. Lindemann
K. Skalski
W. Włosiński
J. Zimmerman
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Abstract

It is not easy to make the insulators of the railway catenary for the dry and cold environment of the icy Qinghai-Tibet plateau, without causing serious ice-related flashover accidents. To study the operating status of catenary icing insulators, a two-dimensional icing model of catenary cantilever insulators was established based on the winter environmental characteristics of the Golmud station on the Qinghai-Tibet Railway. Compared different directions of ice growth, the spatial electric field distribution, and surface temperature distribution characteristics of icing insulatorswere analyzed by multi-physical field coupling simulation. The results show that as the thickness of the ice layer increases and the length of the icicle increases, the field intensity of the insulator gradually increases, and the surface temperature continues to rise. When the ice edge grows vertically downward, the electric field intensity of the insulator is the smallest, and the electric field intensity is the largest when the ice edge grows horizontally. Although the surface temperature of the insulator will rise with the increase of icing degree, it is lower than the freezing point and will not have a great impact on insulation performance. Secondly, when the cantilever insulator is arranged obliquely, the increase in the inclination angle will cause the electric field to increase and the temperature to rise slightly, so the inclination angle of the oblique cantilever should be reduced as much as possible during installation. Finally, the insulator with better insulation performance is obtained by optimizing the structure of the flat cantilever insulator.
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Bibliography

[1] Meng Hong, Qinghai-Tibet Railway: The Magical "Sky Road" on the Roof of theWorld, Party Member’s Digest, no. 11, pp. 38–40 (2019).
[2] Fofana I., Farzaneh M. et al., Dynamic Modeling of Flashover Process on Insulator under Atmospheric Icing Conditions, 2001 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, Toronto, Canada, pp. 605–608 (2001).
[3] Tavakoli C., Farzaneh M., Fofana I. et al., Dynamics and Modeling of AC Arc on Surface of Ice, IEEE Transactions on Dielectrics and Electrical Insulation, vol. 13, no. 06, pp. 1278–1283 (2006).
[4] Zhao Jiayao, Study on AC Flashover Characteristics of Nature Icing Suspension Insulator (Short) Strings, PhD Thesis, Chongqing University, Chongqing (2019).
[5] Zhang Zhijin, Cheng Yang, Zhao Jiayao et al., AC Flashover Performances of Artificial Icing and Nature Icing for XP-160 Insulator String, High Voltage Engineering, vol. 44, no. 09, pp. 2777–2784 (2018).
[6] Ciesielka W., Gołas A. et al., Reliability improvement of power distribution line exposed to extreme icing in Poland, Archives of Electrical Engineering, vol. 68, no. 05, pp. 1113–1125 (2020).
[7] Mhaguen N., Development of Dynamic Models for Predicting the Critical Flashover Voltage of Insulators Covered with Ice Based on Finite Element Method, Thesis of Master’s Degree, University of Québec, Canada (2011).
[8] Volat C., Farzaneh M. et al., Improved FEM models of one- and two-arcs to predict AC critical flashover voltage of ice-covered insulators, IEEE Transactions on Dielectrics and Electrical Insulation, vol. 18, no. 02, pp. 393–400 (2011).
[9] Lu Jiazheng, Xie Pengkang et al., Electric field simulation and sheds optimization of anti- icing and anti- lightning insulator under heavy icing condition, Electric Power Automation Equipment, vol. 38, no. 03, pp. 199–204 (2018).
[10] Tu Yewei, Xia Qiangfeng, Simulation of Space Electric Field Distribution Around 220 kV Porcelain Insulator String (XP-160) and the Influencing Factors, High Voltage Apparatus, vol. 48, no. 03, pp. 67–74 (2012).
[11] Qi Guiming, Wang fake, He Haicheng et al., Surface and low altitude wind field characteristics in Golmud city, Journal of Arid Land Resources and Environment, vol. 24, no. 06, pp. 118–120 (2010).
[12] Hu Yuyao, Study on Dynamic Model for Icing with Wet Growth Process and Ice Flashover Voltage Prediction of Suspension Insulators, Master Thesis, Chongqing University, Chongqing (2017).
[13] Luo Jian, The Optimization of the System Parameters and Cantilever and Positioning Device of Overhead Contact System of High-speed Railway, PhD Thesis, Southwest JiaotongUniversity, Chengdu (2017).
[14] Zhang Yuexin, Study on Catenary’s Construction Techniques in High-speed Electric Railway, PhD Thesis, Southwest Jiaotong University, Chengdu (2006).
[15] Sharma R.P., Seema Tinker et al. Effect of Convective Heat and Mass Conditions in Magnetohydrodynamic Boundary Layer Flow with Joule Heating and Thermal Radiation, International Journal of Applied Mechanics and Engineering, vol. 25, no. 03 (2020).
[16] Liao Jiajun, Yang Lin, Hao Yanpeng, Simulation of Electric Field for 110 kV Iced Composite Insulator in Melting Period, High Voltage Apparatus, vol. 51, no. 03, pp. 47–54 (2015), DOI: 10.13296/ j.l001-1609.hva.2015.03.008.
[17] Ravisha M., Raghunatha K.R., Mamatha A.L., B oundary effects on electrothermal convection in a dielectric fluid layer, Archives of Electrical Engineering, vol. 40, no. 1, pp. 3–19 (2019).
[18] Van Brunt R.J., Stochastic properties of partial-discharge phenomena, Electrical Insulation, IEEE Transactions, vol. 26, iss. 5 (1991), DOI: 10.1109/14.99099.
[19] An Dawei, Study on Needle-plate corona Discharge and Migration Characteristics of Ion Space Charge, PhD Thesis, Chongqing University, Chongqing (2017).

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Authors and Affiliations

Sihua Wang
1
ORCID: ORCID
Junjun Wang
1
Lijun Zhou
1
Long Chen
1
ORCID: ORCID
Lei Zhao
1

  1. Lanzhou Jiaotong University, China
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Abstract

The non-stationary problem of temperature distribution in a circular cylindrical channel of infinite length filled with a homogeneous biomass material moving with a constant velocity in the axial direction was investigated. The heat source was a shaftless helical screw (or auger), which was heated with an electric current due to the Joule–Lenz effect and rotated uniformly around the axis of symmetry of the channel. Similar problems arise in the thermal processing of biomaterials using screw conveyor in pyrolysis and mass sterilization and pasteurization of food products. The problem is solved using the expansion of given and required functions in Fourier series over angular coordinate and integral Fourier and Laplace transforms over axial coordinate and time, respectively. As a result, the temperature field is obtained as the sum of two components, one of which, global, is proportional to time, and the other, which forms the microstructure of the temperature profile, is given by Fourier–Bessel series. The coefficients of the series are determined by the integrals calculated using the Romberg method. Based on the numerical calculations, the analysis of the space-time microstructure of the temperature field in the canal was performed. A significant dependence of the features of this microstructure on the geometric, kinematic and thermodynamic characteristics of the filling biomass and the screw was revealed.
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Bibliography

Abramowitz M., Stegun I.A. (Eds), 1972. Handbook of mathematical functions with formulas, graphs, and mathematical tables. Dover Publ., Inc., New York.

Aramideh S., Xiong Q., Kong S.C., Brown R.C., 2015. Numerical simulation of biomass fast pyrolysis in an screw reactor. Fuel, 156, 234–242. DOI: 10.1016/j.fuel.2015.04.038.

Biogreen, 2016. The pyrolyzer Spirajoule®. Available at: https://www.biogreen-energy.com/spirajoule.

Bortolamasi M., Fottner J., 2001. Design and sizing of screw feeders. PARTEC 2001, International Congress for Particle Technology. Nuremberg, Germany, 27–29 March 2001.

Campuzano F., Brown R.C., Martínez J.D., 2019. Auger reactors for pyrolysis of biomass and wastes. Renewable Sustainable Energy Rev., 102, 372–409. DOI: 10.1016/j.rser.2018.12.014.

Carleton A.J., Miles J.E.P., Valentin F.H.H., 1969. A study of factors affecting the performance of screw conveyers and feeders. J. Eng. Ind., 91, 329-333. DOI: 10.1115/1.3591565.

Carslaw H.S., Jaeger J.C., 1959. Conduction of heat in solids. Clarendon Press, Oxford.

Cheney W., Kincaid D., 2008. Numerical mathematics and computing. Thomson Brooks/Cole, Belmont.

ETIA S.A.S., 2019. Thermal processing of bulk and powders powered by electricity. Available at: https://etiagroup. com/operations-for-thermal-processing.

Evstratov V.A., Rud A.V., Belousov K.Y., 2015. Process modelling vertical screw transport of bulk material flow. Procedia Eng., 129, 397–402. DOI: 10.1016/j.proeng.2015.12.134.

Guda V.K., Steele P.H., Penmetsa V.K., Li Q., 2015. Fast pyrolysis of biomass: Recent advances in fast pyrolysis technology, In: Pandey A., Bhaskar T., Stöcker M., Sukumaran R. (Eds.), Recent advances in thermochemical conversion of biomass. Elsevier, Amsterdam etc., 175-211.

Henan Pingyuan Mining Machinery, 2015. What factors that affect the screw conveyor conveying efficiency? Available at: https://www.pkmachinery.com/faq/factors–affect–screw-conveyor-conveying-efficiency.html.

Korn G.A., Korn T.U., 2000. Mathematical handbook for scientists and engineers: Definitions, theorems and formulas for references and review. Dover Publ., Inc., Mineola, New York.

Kovacevic A., Stosic N., Smith I., 2007. Screw compressors: Three dimensional computational fluid dynamics and solid fluid interaction. Springer-Verlag, Heidelberg, Berlin, New York. DOI: 10.1007/978-3-540-36304-0.

Krein S.G. (Ed.), 1972. Functional analysis. Wolters-Noorhoff Publ., Groningen.

Ledakowicz S., Stolarek P., Malinowski A., Lepez O., 2019. Thermochemical treatment of sewage sludge by integration of drying and pyrolysis/autogasification. Renewable Sustainable Energy Rev., 104, 319–327. DOI: 10.1016/j.rser.2019.01.018.

Lepez O., Sajet P., 2009. Patent No. WO 2009/095564 A3. Device for the thermal processing of divided solids. Luikov A.V., 1968. Analytical heat diffusion theory. Acad. Press, New York etc.

Martelli F.G., 1983. Twin-screw extruders: A basic understanding. Van Nostrand Reinhold Co, New York.

Martínez J.D., Murillo R., Garcia T., Veses A., 2013. Demonstration of the waste tire pyrolysis process on pilot scale in a continuous screw reactor. J. Hazard. Mater., 261, 637–645. DOI: 10.1016/j.jhazmat.2013.07.077.

Nachenius R.W., Van De Wardt T.A., Ronsse F., Prins W., 2015. Residence time distributions of coarse biomass particles in a screw conveyor reactor. Fuel Process Technol, 130, 87–95. DOI: 10.1016/j.fuproc.2014.09.039.

Shi X., Ronsse F., Roegiers J., Pieters J.G., 2019a. 3D Eulerian-Eulerian modeling of a screw reactor for biomass thermochemical conversion. Part 1: Solids flow dynamics and back-mixing. Renewable Energy, 143, 1465-1476. DOI: 10.1016/j.renene.2019.05.098.

Shi X., Ronsse F., Nachenius R., Pieters J.G., 2019b. 3D Eulerian-Eulerian modeling of a screw reactor for biomass thermochemical conversion. Part 2: Slow pyrolysis for char production. Renewable Energy, 143, 1477-1487. DOI: 10.1016/j.renene.2019.05.088.
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Authors and Affiliations

Stanisław Ledakowicz
1
ORCID: ORCID
Olexa Piddubniak
1

  1. Faculty of Process and Environmental Engineering, Lodz University of Technology, Wolczanska St. 215, 90-924 Lodz, Poland
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Abstract

The paper consists the problem of developing a scientific toolkit allowing to predict the thermal state of the ingot during its formation in all elements of the casting and rolling complex, between the crystallizer of the continuous casting machine and exit from the furnace. As the toolkit for the decision making task the predictive mathematical model of the ingot temperature field is proposed. Displacement between the various elements of the CRC is accounted for by changing the boundary conditions. Mass-average enthalpy is proposed as a characteristic of ingot cross-section temperature state. The next methods of solving a number of important problems with the use of medium mass enthalpy are developed: determination of the necessary heat capacity of ingots after the continuous casting machine for direct rolling without heating; determination of the rational time of alignment of the temperature field of ingots having sufficient heat capacity for rolling after casting; determination of the total amount of heat (heat capacity) required to supply the metal for heating ingots that have insufficient amount of internal heat.

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Authors and Affiliations

A. Biryukov
A. Ivanova
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Abstract

To study the influence of temperature field and stress field on the cracking of the small thickness steel plate concrete composite shear wall (SPCW) in the early stage of construction. The temperature field and stress field of a 400 mm thickness SPCW was monitored and simulated through experimental research and numerical simulation. Moreover, a series of parameter analyses were carried out by using ANSYS to investigate the distribution of temperature field and stress field of SPCW. Based on the analysis results, some suggestions are put forward for controlling the cracking of SPCW in the early stage of construction. The results show that the temperature stress of 400 mm thickness SPCW in the early stage of construction is small, and there is no crack on the wall surface. For SPCW with thickness less than 800mm, the temperature stress caused by hydration heat in the early stage of construction is small, and the wall will not crack. The parameters such as wall thickness, steel plate thickness, boundary condition and stud space significantly influence the temperature field and stress field distribution of the small thickness SPCW in the early stage of construction, and reasonable maintenance measures can avoid cracking.
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Authors and Affiliations

Yun Sun
1
Yaojie Guo
1

  1. Wuhan University, School of Civil Engineering, No.8 of Donghu South Road in Wuhan, Hubei, China
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Abstract

The non-uniformity of temperature field distribution of long-span steel structure is proportional to the intensity of solar radiation. Based on the background of Guangzhou Baiyun Station large-span complex steel roof structure, this paper studies the non-uniformtemperature field distribution of large-span steel structure under the Summer Solstice daily radiation-thermal-fluid coupling action based on Star-ccm¸ finite element software, and uses Spa2000 software to analyze the stress and deformation of steel roof under temperature action. Combined with the on-site temperature monitoring, the maximum difference with the measured value is 2.5˚C compared with the numerical simulation results, which verifies the validity of the finite element simulation. The results show that: from 8:00, with the increase of solar altitude angle, the intensity of solar radiation increases, the temperature rises, and the temperature distribution of large-span steel structure becomes more and more non-uniform. From14:00 to18:00, the solar radiation weakens, and the temperature distribution tends to be uniform. Finally, reasonable construction suggestions and measures are proposed to reduce the adverse effects of temperature effects, which can provide theoretical references for the safe construction and normal operation of large-span steel structures located in the subtropics.
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Authors and Affiliations

Pengcheng Jiang
1
ORCID: ORCID

  1. Station Construction Command, China Railway Guangzhou Group Co., Ltd., Guangzhou, Guangdong, China

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