Influence of Heat Transfer Boundary Conditions on the Temperature Field of the Continuous Casting Ingot

2012 ◽  
Vol 57 (1) ◽  
Author(s):  
Z. Malinowski ◽  
T. Telejko ◽  
B. Hadała
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Continuous Casting ◽  
Boundary Conditions

Simulation to the Temperature Field for Continuous Casting Billet during Direct Rolling of Free-Heating

2014 ◽  
Vol 941-944 ◽  
pp. 1890-1894
Author(s):  
Guang Zheng Luo ◽  
Xin Liu ◽  
Ying Zhi ◽  
Xiang Hua Liu
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Finite Element ◽  
Temperature Field ◽  
Continuous Casting ◽  
Transfer Process ◽  
Heat Transfer Process ◽  
Direct Rolling ◽  
Cutting Point ◽  
Continuous Casting Billet

The temperature field of continuous casting billet (CC-billet) is important to carry out the research on direct rolling of free-heating (DROF). The solidification and the heat transfer process of CC-billet from crystallizer to cutting point were studied by finite element method (FEM).The casting speed was improved in order to get reasonable temperature field during DROF.

scholarly journals Mathematical model of heat transfer in roll caliber

2019 ◽  
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Boundary Value Problem ◽  
Boundary Conditions ◽  
Heat Equation ◽  
Rolling Mill ◽  
Thermal Process ◽  
Stationary Heat

A physical model of the thermal process in the roll caliber during the rolling of the tape on a two-roll rolling mill was constructed. A mathematical model of the temperature field of a rolling hollow roll of a rolling state of a cylindrical shape rotating about its axis with constant angular velocity is proposed. The mathematical model takes into account different conditions of heat exchange of the inner and outer surfaces of the roll with the belt and its surrounding environment. The temperature field of a hollow roll of a rolling mill is considered as an initial boundary-value problem for a homogeneous non-stationary heat equation with inhomogeneous, nonlinear boundary conditions, which also depend on the angle of rotation of the roll around its axis. The equation describes the temperature field of the rolls during uncontrolled heat transfer during rolling. It significantly depends on the time and number of revolutions around its axis. With a large number of revolutions of the roll around its axis, a quasi-stationary temperature distribution occurs. Therefore, the simplified problem of determining a quasistationary temperature field, which is associated with a thermal process that is time-independent, is considered further in the work. In this case, the temperature field is described using the boundary value problem in a ring for a homogeneous stationary heat equation with inhomogeneous boundary conditions and heat transfer conditions outside the ring, which lie from the angular coordinate. After the averaging operation, the solution of this problem is reduced to solving the equivalent integral equation of Hammerstein type with a kernel in the form of the Green's function. The Mathcad computer mathematical system builds the temperature distribution of the roll surface. An algorithm for solving a inhomogeneous problem was developed and the temperature distribution of the roll was constructed.

Numerical Model of Heat Transfer and Mass Transfer During the Solidification of a Concasting Steel

2011 ◽  
Author(s):  
Josef Stetina ◽  
Frantisek Kavicka
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Numerical Model ◽  
Boundary Conditions ◽  
Energy Content ◽  
Cast Billet ◽  
Convection Coefficient ◽  
Transfer Coefficients ◽  
Correct Process ◽  
Real Process

The accuracy with which the solidification and cooling of a continuously cast billet is investigated depends on the setting of the boundary conditions of the numerical model of the temperature field. An in-house numerical model of the 3D temperature field of a concast billet had been used. This model enables the analysis of the temperature field of the actual blank as it passes through the zero-, primary-, secondary- and tertiary-cooling zones, i.e. through the entire caster. This paper deals with the derivation of transfer phenomena under the cooling nozzles of the secondary zone. These phenomena are expressed by the values of the heat transfer coefficients (HTCs). The dependences of these coefficients on surface temperature and other operational parameters must also be given. The HTCs beneath the nozzles are given by the sum of the forced convection coefficient and the so-called reduced convection coefficient corresponding to heat transfer by radiation. The definition of the boundary conditions is the most difficult part of the numerical and experimental investigation of the thermokinetics of this process. Regarding the fact that on a real caster, where there are many types of nozzles (with various settings) positioned inside a closed cage, it is practically impossible to conduct measurement of the real boundary conditions. Therefore, an experimental laboratory device was introduced in order to measure the cooling characteristics of the nozzles. It simulates not only the movement, but also the surface of a blank and for the necessary range of water flow in the operation and the casting speeds. The transfer phenomena beneath the water cooling nozzles are presented on a simulated temperature field for a real 150×150 mm steel billet under different operational conditions. This is ensured by the correct process procedure: real process → input data → numerical analysis → optimization → correction of process. The presented model is a valuable computational tool and accurate simulator for investigating transient phenomena in caster operations, and for developing control methods, the choice of an optimum cooling strategy to meet all quality requirements, and an assessment of the heat-energy content required for direct rolling.

Heat Transfer Boundary Conditions of Piston of Aviation Reciprocating Engine

2014 ◽  
Vol 602-605 ◽  
pp. 357-360
Author(s):  
Shu Xian Chen ◽  
Xin Meng ◽  
Xiang Chuan Guo ◽  
Yong Zhang
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Theoretical Analysis ◽  
Boundary Conditions ◽  
Piston Ring ◽  
Thermal Loads ◽  
Reciprocating Engine ◽  
Engine Piston

To assess piston’s thermal loads, the direct and effective method is to calculate piston’s temperature distribution. A key point in calculating the temperature field of a piston is the determination of heat transfer boundary conditions of each side, especially the gas side. The thermal boundaries of a piston consist of the piston top side (combustion side), the crevice surfaces, the piston ring land and skirt outside surface, piston underside and pin hole side.The calculating methods for the heat transfer boundary conditions of engine piston are studied according to the theoretical analysis of heat transfer of engine piston, which can be taken as a reference for providing precise boundary conditions for the research on piston’s temperature field.

Assessment of Cooling Conditions of a Continuous Casting Machine for Steel Billets Based on Surface Temperature Measurements

2012 ◽  
Vol 730-732 ◽  
pp. 841-846
Author(s):  
Noé Cheung ◽  
Leonardo L. Taconi ◽  
Amauri Garcia
Keyword(s):  
Heat Transfer ◽  
Continuous Casting ◽  
Boundary Conditions ◽  
Surface Temperature ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Temperature Evolution ◽  
Cooling Zone ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients

For the correct simulation of solidification and temperature evolution in the continuous casting of steel, the determination of boundary conditions describing the heat-transfer phenomena through the strand surface, in each cooling zone of the casting machine, is extremely important. These boundary conditions are usually expressed as heat fluxes or heat transfer coefficients. In the present study, the surface temperature of the steel billet was experimentally determined in a steelmaking plant by infrared pyrometers positioned along the secondary cooling zone during real operation of a continuous casting machine. These data were used as input information into an Inverse Heat Transfer Code, implemented in this work, in order to permit the heat transfer coefficients of each spray cooling zone to be determined. The resulting simulations of temperature evolution during continuous casting have shown that the solidification was not complete at the unbending point and that there was a risk of breakout at the mold exit under the adopted operating conditions.

scholarly journals Calculation of temperature and thermoelastic stresses in backups with collars of the unit of combined continuous casting and deformation in steel billets production. Report 1

2021 ◽  
Vol 63 (11-12) ◽  
pp. 960-964
Author(s):  
O. S. Lekhov ◽  
A. V. Mikhalev
Keyword(s):  
Temperature Field ◽  
Continuous Casting ◽  
Boundary Conditions ◽  
Contact Layer ◽  
Temperature Fields ◽  
Field Calculation ◽  
Conductivity Equation ◽  
Thermal Conductivity Equation ◽  
Thermoelastic Stresses ◽  
Effective Heat Transfer Coefficient

The article describes the main loads affecting shaped backups of the unit of combined process of continuous casting and deformation in billets production. Importance of determining the temperature fields and thermoelastic stresses in shaped backups with collars is provided at formation of several billets, at slab compression and at idle during water cooling of backups. The authors describe strength and thermophysical properties of steel from which the backups are made. Geometry of backups with collars used for obtaining billets of three different shapes in one pass is shown. Initial data of the temperature field calculation are given for backups with collars of the combined unit. Temperature boundary conditions are considered for calculation of temperature fields of backups with collars. Boundary conditions determining temperature of such backups are described and values of the heat flow and effective heat transfer coefficient are given. The results of calculation of temperature fields are performed in four sections and are given for typical lines and points located on contact surface of backups with collars and in contact layer at depth of 5 mm from the working surface. The sizes of finite elements grid which is used at calculation of temperature field of backups with collars are provided. Temperature field of backups with collars is determined on the basis of solution of unsteady thermal conductivity equation corresponding initial and boundary conditions. Values and regularities of temperature distribution in bases and in tops of the middle and extreme edges of the shaped backups are presented during slab compression and at idle when obtaining billets of three shapes in one pass at the unit of combined continuous casting and deformation.

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