两段式喷煤填充床内煤粉分布规律的试验研究

Experimental Study on Distribution of Pulverized Coal in the Packed Bed with Bi-PCI Process

根据相似原理建立了1∶25的二维冷态填充床模拟高炉喷吹煤粉,通过试验比较了一段式喷煤和两段式喷煤条件下填充床内煤粉的分布规律和压差变化.结果表明:煤粉主要堆积在填充床下部,随高度的增加,煤粉的堆积量呈下降趋势.第二段喷入的煤粉大部分堆积于填充床边缘区域,中心区域堆积的煤粉主要为风口喷入.在喷煤量相同条件下,两段式喷煤时模型高度方向上煤粉分布更加均匀,填充床透气性得到改善;两段式喷煤与一段式喷煤相比,填充床内总压差下降了约29%,主要是填充床下部的压差显著降低;第二段喷入填充床内的煤粉对填充床上部的压差影响不大.

A two-dimensional packed bed model was established with 1∶ 25 scale for simulating the PCI（pulverized coal injection）process and the Bi-PCI（bisegment pulverized coal injection）process based on similarity theory.The distributions of powder and pressure were investigated when PCI and Bi-PCI were used respectively.The results showed that the pulverized coal mainly accumulates in the lower part of packed bed,and the accumulation of pulverized coal decreases with increasing height of packed bed.The pulverized coal from the second lance accumulates in the edge region of the packed bed,and the holdup of the mid region is from the tuyere.At the same conditions,the distribution of pulverized coal becomes more uniform at height direction,and the permeability of packed bed is improved when Bi-PCI is adopted.So the pressure drop in packed bed is reduced by 29% compared with the PCI,mainly because the pressure drop significantly decreases in lower part of packed bed.The pulverized coal that have been injected by the secondary lance has little influence on the pressure drop in the upper of the packed bed.