Numerical Simulation Of Heating Process Of Glass Melting Furnace

The development and application of glass electrofusion technology is a major technological revolution in glass melting industry.With the continuous development and progress of the society,the melting process of glass electric melting furnace needs to be further explored in order to improve the efficiency of glass production and the quality of glass products.As the most important thermal equipment in the glass manufacturing process,the performance of the glass electric melting furnace would directly determine the quality of the final product and the service life of the melting furnace.Therefore,obtaining an all-round comprehension of the process of glass electrofusion is the only way to lay a firm theoretical foundation to improve the efficiency and quality of grass production.At present,there are still many problems in glass electrofusion technology,such as the distribution of electric field in the melting furnace under different electrode deployment,how to adjust the structure and energy supply of the melting furnace to achieve optimal production,how the electric energy and heat as well as melt flow in the melting furnace affect and restrict each other,etc.Only by figuring out the answers to these questions could the designer design electric melting furnace with better performance to meet the rquirements of glass characteristics.Applying numerical simulation method,this thesis,with the aid of 1 m*1 m*1 m cube furnace structure designed by predecessors,used a pair of rod electrodes for bottom inserting,side inserting and top inserting inside the furnace,explored how current density,power density,temperature and flow changes with the hearting time under different electrode deployment inside the melting furnace and probed into how the physical field changes with the heat preservation time inside the bottom inserting furnace.The simulation was conducted by using the commercial software Fluent.By loading the UDF file,the control electrode provides intermittent power to the melting furnace to realize the insulation process of the melting furnace.The PISO method was used for transient problems with large time step.The accuracy of the results is verified by comparing the previous research conclusions.The research results give the distribution of current density,power density,temperature and flow rate in the electric melting furnace under different electrode arrangements.The results show that during the heating process of the three types of electric melting furnace,the melt current density and power density in the vicinity of and between the two electrodes are relatively concentrated,which are 10³¹0⁴ A/m²,10⁶¹0⁸W/m³respectively,and with the increase of the melt temperature in the furnace,it will concentrate in the high temperature area.The melt in the bottom-plug electric melting furnace shows a large temperature gradient in the horizontal direction;the melt in the side-plug electric furnace has a relatively uniform temperature distribution between Z=0.4-0.7m,and the average temperature is about 2.5×10³K;the top melt temperature of the top plug-in electric furnace is 4 664K.The high temperature melt produced by heating is easy to accumulate on the top of the furnace due to buoyancy.In actual production,the input power of the electrode should not be too large,otherwise it may cause the melting furnace to red top,flip top.The maximum flow velocity of the melt in the three melting furnaces is on the order of 10^-3m/s.The rising high temperature melt is blocked at the top of the melting furnace and diverts to cause high temperature at the top.The ascending melt in the middle and the bottom flows in the opposite direction to the top reflux melt,resulting in a circulation at the top of the furnace.After heat-insulating the bottom-inserted electric melting furnace for 13 940s,the melt temperature in the furnace tends to be consistent,the maximum temperature is reduced from about 4 000K to about 2 000K,the maximum order of flow velocity drops from 10-3m/s to 10-4m/s,and the core position of the circulation remains stable.This result reveals the coupling relationship between electricity,heat and flow in the glass electric melting furnace,which has guiding significance for the design and optimization of the actual melting furnace.