Analysis of rate of hydrogen reduction of porous wustite pellets basing on zone-reaction models.
Analysis of rate of hydrogen reduction of porous wustite pellets basing on zone-reaction models.
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DOI：
10.2355/isijinternational.30.347
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发表时间：
1990-05
影响因子：
1.8
通讯作者：
T. Usui;M. Ohmi;E. Yamamura
中科院分区：
文献类型：
--
作者：
T. Usui;M. Ohmi;E. Yamamura
在900°C下用氢气还原多孔浮氏体颗粒，测量还原曲线、反应区位置和局部分数还原曲线，重新检查并按原样（非稳态数值解）、准稳态（准稳态数值解）和线性化近似（准稳态解析解）求解颗粒模型的基本方程。当在每种情况下适当地选择速率参数值时，测量的还原曲线和反应区行为由计算结果比较好地再现。在目前的实验条件下，Thiele模量约为10-14，反应方式与未反应核收缩模型的反应方式有很大不同，在计算非稳态数值解时，将可还原氧密度除以M以减少计算时间; M≤2000时的误差在允许范围内，尽管在M=1时得到了最忠实于基本方程的解。非定常数值解与准定常数值解的比较表明，准定常数值解是一种具有较好精度的近似解。从实用的角度来看，准定常解析解的计算时间最短，且实测结果与计算结果的吻合程度相当。
Porous wustite pellets were reduced with hydrogen at 900°C, and reduction curves, position of reaction zone and local fractional-reduction profiles were measured.Basic equations for the grain model were re-examined and solved as they were (unsteady numerical solution), and under quasi-steady (quasi-steady numerical one) and moreover linearization approximations (quasi-steady analytical one). When rate parameter values are selected suitably in each case, measured reduction curves and reaction zone behavior are comparatively well reproduced by the calculated results. Thiele's modulus is about 10-14 under the present experimental conditions and reaction fashion differs much from the one for unreacted-core shrinking model.When the unsteady numerical solution is calculated, reducible oxygen density is divided by M to reduce the computation time; the error at M≤2000 is within a permissible range, although the solution most faithful to the basic equations is obtained at M=1. Comparison between the unsteady and the quasi-steady numerical solutions shows that the latter is an approximate solution having rather good accuracy. The quasi-steady analytical solution is better than the others from practical viewpoint, because its computation time is the shortest and degree of agreement between the measured and the calculated results is much the same among the three.