Modelling and numerical simulation of isothermal oxidation of an individual magnetite pellet based on computational fluid dynamics

• 作者: Zhou Pu Feng Zhou Yue Sun Ming Zhang Bo-quan Li
• 来源期刊: 钢铁研究学报（英文版）
• 年，卷（期）: 2021,（7）
• 所属期刊栏目: ORIGINAL PAPERS
• 页码范围: 799-808
• 页数: 10页
• 语种: 英文

摘要

A mathematical model based on the computational fluid dynamics method,heat and mass transfer in porous media and the unreacted shrinking core model for the oxidation reaction of an individual magnetite pellet during preheating was established.The commercial software COMSOL Multiphysics was used to simulate the change in the oxidation degree of the pellet at different temperatures and oxygen concentrations,and the simulated results were compared with the exper-imental results.The model considered the influence of the exothermic heat of the reaction,and the enthalpy change was added to calculate the heat released by the oxidation.The results show that the oxidation rate on the surface of the pellet is much faster than that of the inside of the pellet.Temperature and oxygen concentration have great influence on the pellet oxidation model.Meanwhile,the exothermic calculation results show that there is a non-isothermal phenomenon inside the pellet,which leads to an increase in temperature inside the single pellet.Under the preheating condition of 873-1273 K(20％oxygen content),the heat released by the pellet oxidation reaction in a chain grate is 7.8×106-10.8×106 kJ/h,which is very large and needs to be considered in the magnetite pellet oxidation modelling.