高炉喷吹煤粉颗粒与热风间动量能量交换的数值仿真

Numerical simulations of momentum and heat exchange between pulverized coal particles and hot gas in blast furnace

为了揭示高炉风口回旋区周边颗粒对煤粉颗粒受力和传热特性的影响机理,建立了基于CPU-GPU异构并行模式的三维浸没边界-格子Boltzmann法(IB-LBM)模型,针对串列三颗粒在流场中的曳力和传热特征开展数值模拟研究,详细讨论了雷诺数(10≤Re≤100)和颗粒间距(s=2D,4D)对曳力系数Cd和平均努塞尔数Nu的影响.结果表明:第2个和第3个颗粒置入后,随着Re的增大,3个颗粒的Cd均减小(Cd_(1)>Cd_(2)>Cd_(3)),而3个颗粒的Nu均增大(Nu1>Nu2>Nu3);根据数值模拟结果,分别构建了串列三颗粒的Cd与Nu的新关联式,新关联式得出的Cd和Nu预测值与数值模拟结果相比,最大误差分别为2.5449%和0.4480%,这表明该关联式适用于高炉喷吹煤粉颗粒在热风中受力和传热机制的数值仿真过程.

In order to reveal the influence mechanism of the surrounding particles on the force and heat transfer characteristics for pulsedcoal particles in the blast furnace tuyere,a three⁃dimensional immersed boundary⁃lattice Boltzmann model(IB⁃LBM)based on CPU⁃GPU heterogeneous architecture is built.The momentum and heat transfer characteristics of three particles in tandem arrangement with fluids are studied,and the effects of Reynolds number(10≤Re≤100)and particle distance(s=2D,4D)on the drag coefficient(Cd)and average Nusselt number(Nu)are discussed in detail.Numerical results show thatwhen the other two particles are put into the system with the existing one,the Cd of all the three particles decreases with increasing Re,and Cd_(1)>Cd_(2)>Cd_(3).Furthermore,the Nu of the three particles also increases as Re increases,and Nu1>Nu2>Nu3.Based on the current numerical results,new correlations of Cd and Nu are constructed considering the influence of surrounding particles with the maximum errors of 2.5449%and 0.4480%,respectively.They can be easily used for the numerical simulations of momentum and heat exchange characteristics of pulverized coal particles and hot gas during the blast furnace blowing process.