氧气高炉新型氧煤燃烧器设计参数对风口区流场影响数值模拟

Numerical analysis of flow behavior in tuyere and raceway of oxygen blast furnace with new type of oxy-coal burner

氧气高炉通过向风口回旋区喷吹煤粉以及脱除CO_2的循环高炉煤气,可有效降低CO_2排放。运用CFD商业软件,建立风口回旋区三维模型,针对氧气高炉所设计的新型燃烧器中氧煤枪数量及其与直吹管所呈角度和空间物理位置对风口回旋区流场的影响进行数值模拟。研究结果表明：采用单支氧煤枪操作,当其位于直吹管上部时,煤气流速度随喷吹角度由7°～15°变化时逐渐减小,且夹角为9°较为适宜,当其位于下部时,随着夹角越大,对风口回旋区深度增加越有利;采用双氧煤枪操作,当其在直吹管上下、左右分布时,夹角分别为11°和13°较合理;当单支氧煤枪位于直吹管上方且夹角为9°、距离d为75 mm时能较好地促进风口回旋区深度增加并保持足够的鼓风动能。

Oxygen blast furnace can effectively reduce CO_2 emissions by two means, pulverized coal injection and recycling of CO_2-removed blast furnace gas. To study the velocity field among the tuyere and raceway region, a three-dimensional model was build up using the commercial CFD software. The factors these numerical simulations mainly focus on the number of oxygen-coal lances, the angle and distance between the blowpipe and oxy-coal lances. Numerical results show that increasing angle between the blowpipe and oxy-coal lance from 7° to 15° results in lower velocity when the oxy-coal lance is set above the blowpipe, the appropriate angle is 9°. When the lance is located below the blowpipe, the bigger the angle is, the deeper the raceway will be. In addition, when the oxy-coal burner has two lances, the lances are set at two sides of the blowpipe, i.e. vertical and horizontal distribution around the blowpipe, and the reasonable angles are 11° and 13°. Besides, the suitable distance between the blowpipe and oxy-coal lance is 75 mm when the oxy-coal lance is set above the blowpipe.