正交两相射流中煤粉燃烧过程的研究

Pulverized-Coal Combustion Process in Two-Phase Crossflow

正交射流冷态空气动力学试验证明,在它的尾迹能够产生一个稳定的回流区.本文进一步试验证明:在回流区的边界上存在高浓度煤粉集聚区;投入副射流后,一次风喷口附近温度从120℃提高到900℃～1000℃,飞灰含碳量降低,煤粉燃烧更加稳定和强化.

When two free jets of different velocity meet with each other orthogonally, the smaller one with a high velocity can penetrate the main one of a larger cross-sectional area, and a steady recirculation zone will occur in the wake behind the smaller jet. The diameter, length and recirculat-ing rate of the recirculating zone will be in the same order of magnitude as those behind a solid bluff-body. Experiments show that when the smaller jet penetrates the main stream that carries pulverized-coal, there exists a high coal pulverized-concentration region on the edge of the recir- culationzone. With the high temperature gas enrolled into the recirculation zone, the temperature of the main stream rises from 120℃ to 900℃~1000℃. The high temperature and high pulverized-coal concentration result in advance ignition, stabilized and strengthened combustion and a reduction of carbon content in the fly ash, thus saving energy.