Roll Shell Heat Transfer Of The Skin Effect And The Parameters Affect The Numerical Simulation Study

Two-roll casting, as a new technology to produce metal planks and strips, has become more and more important for its characters such as short process, high productivity and good product qualities. But the roll-casting machines that our country has being used, not only home-made but also foreign, are conventional roll-casting machines. There are some problems in conventional casting technology, such as low casting speed, defective metal structure and few casting breed. So it is necessary to research the new roll-casting technology-the fast-solidification roll-casting. The key of it is to achieve more quick solidification speed, namely approves the cooling capacity of the system as possible.The roll shells are very important in twin-roll casting process. Its thermal conductivity affects the whole casting process directly. The heat that the melted aluminum gives out in the course of cooling and solidification is mostly transferred to the roll shells, then is absorbed and taken out of by the cooling water. So, it's very important to research the rule of heat transfer and analyze the relation with the roll-casting parameter.In this paper, based on the analysis of heat transfer during twin-roll casting process at home and abroad, the ANSYS software is used to analyzed the rule of heat transfer in the roll shells. The most research is as following:1 The mathematical and physical model of heat transfer in the roll shell is established, especially, the problem about the periodically rotational boundary condition is solved with element mass transport velocity.2 The affect of roll-casting parameters to the temperature and cooling capacity of roll shells, such as rotate speed, length of roll-casting zone, convection heat transfer coefficient with the cooling water and the roll shell material, outer diameter, thickness, are systemically analyzed whether in the conventional or fast-solidification roll-casting. So the best matching parameters is provided for the roll-casting, especially for the fast-solidification roll-casting.3 According to the thermal energy balance principle, the maximal roll-casting speed is worked out in casting strips of various thickness in a certain condition.4 Skin effect of the heat transfer in the roll shells is revealed after the temperature and heat flux is analyzed in detail. This make it clear that the conduction ability of bronze is better than steel greatly.5 The surface temperature of the roll shells is tested during the roll-casting experiment and the relative data is gained. The experiment testifies that the simulation result is consisted with the experiment data basically. Thereby, the model and conclusion is right.