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چكيده انگليسي :

Strip Thermal Modeling in Continuous Annealing Furnace Somayye Asadi Somaye asadi@me iut ac ir Date of Submission Sep 18 2012 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Ahmad Saboonchi ahmadsab@cc iut ac irAbstractContinuous annealing is an efficient process to provide a sound heat treatment on strip materials with higherquality faster delivery and higher thermal efficiency than conventional batch annealing This process isdone to improve the physical and mechanical properties of strips after cold rolled Despite directmeasurement of the final temperature of the strip by a pyrometer an accurate estimation of the striptemperature along the continuous annealing furnace is the main concern to guarantee the quality of the stripmaterial produced The present study investigates the temperature distribution from a strip passing throughthe heating zone of continuous annealing furnace It would be helpful to establish a physical model tosimulate the thermal process taking place in the furnace and then to gain a deeper insight into the detailedmechanisms of heat transfer between components For this purpose a suitable mathematical model has beensuggested to predicate the distribution of the strip temperature for both one dimentional and treedimentional cases Both the direct and indirect contact temperature measurements are difficult to implementdue to serious restrictions regarding the concerns of safety operation and complicated radiation interactionbetween several surfaces in the furnace Therefore the scale of the model accuracy is only the producedtemperature At first a suitable numerical method has been chosen for solving the energy equation Then themechanisms of heat transfer in furnace including free force convection and radiation has beeninvestigated The main heat transfer to strip is by radiation To derermine the boundary condition ofradiation considering the furnace geometry and the existence of the radiand tubes as the heat source theMonte Carlo method has been studied and applied to determine the configuration factors in the wholefurnace The results from the mathematical model designed for this process have been compared against real datafrom annealing furnace in galvanizing line of Mobarakeh Steel Complex The slight error of model indicates the capability of the model in predicating the temperature distribution of strip in furnace Theresults show that despite spending too much time and money three dimentional solution has little effect onthe accurancy of the results Due to the accurate calculation of the configuration factors by Monte Carlomethod one dimensional solution offers more accurate answer Also the results obtained from Monte Carlosolution for calculating the view factor for strip elements to walls in furnace and radiant tubes is presentedfor suitable number of rays and the length of strip In addition the effect of the various parameters such asload emissivities load velocities and load thicknesses on the strip temperature distribution has beeninvestigated Once the accuracy and reliability of this simulation model are validated throughexperimentation the model could be used to adjust the operational parameters to obtain the desired existingstrip temperature Keywords Continuous annealing Galvanizing line Mathematical model Mont Carlo method Radiant tube

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مدل گرمايش ورق در كوره آنيل پيوسته

خط گالوانيزه , مدل رياضي , لوله هاي تشعشعي , روش مونت كارلو