Research On Energy Dissipation Mechanism Of Polysilicon Reduction Furnace Under The Action Of Multi-field Coupling

With the development of information technology and new energy,the demand of polysilicon as the core raw material of semiconductor and photovoltaic industry is increasing day by day.The improved Siemens process has become the main production process of polysilicon with mature process and simple equipment.However,the main problem is that the energy consumption is too high when using this process.The heat transfer process in polysilicon deposition has a major impact on the total energy consumption.In order to solve the problem of high energy consumption in the production process of improved Siemens method,this paper carried out the research on reducing the consumption of polysilicon reduction furnace under the effect of multi field coupling.Based on the theory of computational fluid dynamics(CFD),the fluid dynamics and heat transfer model of reduction furnace were established by introducing the conservation equation of energy,the law of mass conservation,continuity equation,turbulence model and radiation model.The model is applied to study the transfer phenomenon of operating conditions in large(42 pairs of rods)siemens reduction furnace.The distribution of flow field,temperature field and electromagnetic radiation field in the process of convection and heat transfer in the reduction furnace is studied,and the influencing factors and rules of energy consumption are obtained:(1)Through the simple annular silicon rod layout,the annular silicon rod layout model in the reduction furnace is deduced.12 pairs of silicon rod reduction furnaces are used to describe the implementation of silicon rod layout model.42 pairs of silicon rod reduction furnaces are analyzed,and the furnace behavior and rod behavior under different layout modes are obtained,Combined with the furnace behavior and rod behavior in the reduction furnace,the energy consumption of convective heat transfer and radiation heat transfer under different silicon rod radius were analyzed,and the energy consumption law of silicon rod growth process in the reduction furnace was obtained: the temperature field and flow field in the furnace jointly affect the energy consumption of convective heat transfer,with the increase of silicon rod radius,the energy consumption of convective heat transfer in the furnace increases,and the radius of silicon rod affects the energy consumption of radiation heat transfer in the furnace,With the increase of the silicon rod radius,the radiation energy consumption of the silicon rod in the furnace relative to the inner ring first increases and then decreases.When the silicon rod radius increases from 30 mm to 50 mm and finally increases to 70 mm,the radiation energy consumption of the silicon rod increases from 517832.38 W to 571554.94 W,and then decreases to 517170.06 W,while the energy consumption of the silicon rod relative to the outer ring increases all the time.In order to reduce the energy consumption of convection heat transfer and radiation heat transfer in the reduction furnace,a new method of reducing the energy consumption of polycrystalline silicon reduction furnace with annular arrangement of silicon rods is proposed.(2)A new type of heat transfer model of reduction furnace is established,which is characterized by the "honeycomb" arrangement of silicon rods.A simulation model describing the flow field,temperature field and electromagnetic field in the reactor is established,and the law of physical field in the reduction furnace under different operating conditions is obtained: the temperature in the furnace increases with the increase of silicon rod temperature,and the radiation intensity in the furnace decreases with the increase of wall emissivity.Different process parameters were used to analyze the energy consumption of the reduction furnace,and the influence on the energy consumption of the reduction furnace was obtained.Finally,the energy consumption under different radius of silicon rod is analyzed by coupling multi physical field.When the radius of silicon rod in the new type reduction furnace increases from 30 mm to 70 mm,the total energy consumption of the reduction furnace increases from 4053649.23 W to 5831481.13 W.Compared with the traditional reduction furnace,the total energy consumption of the new type reduction furnace is11.86% less than that of the four ring arrangement.