大型电站锅炉燃烧器区向火侧剪切大涡的尺度及其旋转速度

采用IFA30 0恒温式热线风速仪 ,首次使用六线涡量探针及其定位坐标系统 ,对具有普适性的HG - 2 0 0 8-YM2型切向燃烧煤粉锅炉燃烧器区的涡量场进行了测量 ,采用兰金复合涡 (RankineVortex)旋涡模型描述了切向炉四角燃烧器射流向火侧的剪切大涡 ,由冷模试验确定了该剪切大涡的尺度及其旋转速度 ,该剪切大涡的涡核半径r0 为 2 5mm ,炉内流体微团作刚体式旋转的角速度为 - 1.5 6× 10 5r/min ,分析了剪切大涡对煤粉着火以及燃烧器区涡相干结构中NOx初生形态的影响。

Scale and Rotating Velocity of a Big Shear Vortex at the Fire-facing Side of a Burner Region in a Large-sized Utility Boiler

Measurements were taken of the vorticity field in the burner region of a HG-2008-YM2 type tangentially fired pulverized-coal boiler, which is considered as having a universal significance. The above measurements were conducted by employing a IFA300 constant-temperature hot wire anemometer with the use for the first time of a six-sensor hot-wire probe and its locating coordinate system. The big shear vortex at the fire-facing side of the tangentially fired burner jets is described by the use of a Rankine composite vortex. The scale and rotating velocity of the big shear vortex has been determined by a cold model test. The vortex core radius of the big shear is 25mm, and the rotating angular velocity of an in-furnace fluid tiny ball rotating as a rigid body, -1.56 x 105 rmin. The influence of the big shear vortex on pulverized-coal ignition and the NO X nascent state in the relevant structure of the burner zone vortex was also analyzed.