Numerical Analysis of Gas-Solid Heat Transfer Characteristics in Shaft Furnace for Calcination of Sintered Magnesia

doi:10.12068/j.issn.1005-3026.2022.01.006

Abstract

Abstract: Based on the theory of porous media， a three-dimensional heat transfer model for steady gas-solid flow was established for a shaft furnace of sintered magnesia with annual output of 5×10⁴t. The influences of thermal parameters of the shaft furnace on the gas-solid heat transfer process in the bed were simulated. The results show that， with increasing the cooling air flow by 10%， the outlet flue gas temperature decreases by 50℃， and the outlet pellet temperature decreases by 80℃. When the cooling section length increases by 5%， the outlet pellet temperature decreases by 25℃. Taking the flue gas temperature and pellet temperature at the shaft furnace outlet as the optimization objective functions， the optimum structure and operation parameters of shaft furnace are obtained， including the calcination air flow of 2606.67m³/h， the cooling air flow of 2203.34m³/h， the preheating calcination section of 6.64m， and the cooling section of 11.70m. Under this working condition of the shaft furnace， the outlet pellet temperature is 288.75℃， and the outlet flue gas temperature is 414.32℃.

Key words: magnesia pellets; shaft furnace for calcination; gas-solid heat transfer; numerical simulation; parameter optimization

CLC Number:

TF822
TF068

ZHANG Xiao-hu， ZHANG Sheng， ZHAO Liang， DONG Hui. Numerical Analysis of Gas-Solid Heat Transfer Characteristics in Shaft Furnace for Calcination of Sintered Magnesia[J]. Journal of Northeastern University(Natural Science), 2022, 43(1): 40-47.

References

[1]陈庆明，魏同.中国镁质原料的发展现状和展望［J］.耐火材料，2013，47(3):210-214.(Chen Qing-ming，Wei Tong.Status and prospect of China’s magnesia raw materials［J］.Refractories，2013，47(3):210-214.)
[2]李鑫，罗旭东，于忞.我国超高温镁砂竖窑回顾及发展［J］.硅酸盐通报，2017，36(2):503-506.(Li Xin，Luo Xu-dong，Yu Min.Review and development of ultra high shaft kiln of China［J］.Bulletin of the Chinese Ceramic Society，2017，36(2):503-506.)
[3]Rasul M G，Saotayanan D.Modeling and simulation of thermodynamic processes of vertical shaft kiln used for producing deadburned magnesia［J］.International Journal of Energy and Environment，2007，1(1):37-44.
[4]Huang B.Computer model of the shaft kiln process［D］.Rockhampton:Central Queensland University，1999.
[5]肖奋飞，张林进，陈小娟.高温竖窑煅烧区的燃烧数值模拟［J］.工业炉，2014，36(6):13-15.(Xiao Fen-fei，Zhang Lin-jin，Chen Xiao-juan.Combustion numerical simulation on calcining zone of high temperature shaft kiln［J］.Industrial Furnace，2014，36(6):13-15.)
[6]丛伟.新型重烧氧化镁竖炉能源利用分析［J］.冶金能源，2019，38(3):61-63.(Cong Wei.Analysis of energy utilization of dead-burned magnesia shaft furnace［J］.Energy for Metallurgical Industry，2019，38(3):61-63.)
[7]Karimipour-Fard P，Afshari E，Ziaei-Rad M，et al.A numerical study on heat transfer enhancement and design of a heat exchanger with porous media in continuous hydrothermal flow synthesis system［J］.Chinese Journal of Chemical Engineering，2017，25(10):1352-1359.
[8]Ghadi A Z，Valipour M S，Biglari M.CFD simulation of two-phase gas-particle flow in the Midrex shaft furnace:the effect of twin gas injection system on the performance of the reactor［J］.International Journal of Hydrogen Energy，2017，42(1):103-118.
[9]Yaman O，Kulah G，Koksal M.Surface-to-bed heat transfer for high-density particles in conical spouted and spout-fluid beds［J］.Particuology，2019，42:35-47.
[10]Mahmoudi Y.Effect of thermal radiation on temperature differential in a porous medium under local thermal non-equilibrium condition［J］.International Journal of Heat and Mass Transfer，2014，76:105-121.
[11]Hajipour M，Dehkordi A M.Transient behavior of fluid flow and heat transfer in vertical channels partially filled with porous medium:effects of inertial term and viscous dissipation［J］.Energy Conversion and Management，2012，61:1-7.
[12]Saberinejad H，Keshavarz A.Reciprocating turbulent flow heat transfer enhancement within a porous medium embedded in a circular tube［J］.Applied Thermal Engineering，2016，102:1355-1365.
[13]Dickson C，Torabi M，Karimi N.First and second law analyses of nanofluid forced convection in a partially-filled porous channel—the effects of local thermal non-equilibrium and internal heat sources［J］.Applied Thermal Engineering，2016，103:459-480.
[14]Al-Sumaily G F，Nakayama A，Sheridan J，et al.The effect of porous media particle size on forced convection from a circular cylinder without assuming local thermal equilibrium between phases［J］.International Journal of Heat and Mass Transfer，2012，55(13/14):3366-3378.
[15]董辉，冯军胜，李朋，等.球团竖炉结构参数影响炉内气体流动的数值模拟［J］.东北大学学报(自然科学版)，2013，34(7):980-984.(Dong Hui，Feng Jun-sheng，Li Peng，et al.Numerical simulation on gas flow affected by constructional parameters of pelletizing shaft furnaces［J］.Journal of Northeastern University (Natural Science)，2013，34(7):980-984.)
[16]张晟，张晓虎，董辉，等.基于Ergun方程的菱镁球团填充床层阻力特性实验［J］.东北大学学报(自然科学版)，2021，42(3):347-352.(Zhang Sheng，Zhang Xiao-hu，Dong Hui，et al.Experiment of resistance characteristics for magnesite pellets packed bed based on Ergun equation［J］.Journal of Northeastern University(Natural Science)，2021，42(3):347-352.)
[17]Mahmoudi Y，Maerefat M.Analytical investigation of heat transfer enhancement in a channel partially filled with a porous material under local thermal non-equilibrium condition［J］.International Journal of Thermal Sciences，2011，50 (12):2386-2401.
[18]Alazmi B，Vafai K.Analysis of fluid flow and heat transfer interfacial conditions between a porous medium and a fluid layer［J］.International Journal of Heat and Mass Transfer，2001，44(9):1735-1749.
[19]Hwang K S，Jun J H，Lee W K.Fixed-bed adsorption for bulk component system:non-equilibrium，non-isothermal and non-adiabatic model［J］.Chemical Engineering Science，1995，50(5):813-825.
[20]Chen X，Xia X L，Liu H，et al.Heat transfer analysis of a volumetric solar receiver by coupling the solar radiation transport and internal heat transfer［J］.Energy Conversion and Management，2016，114:20-27.