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采用直接数值模拟方法对含尘烟气经过受热面管道的气相场和颗粒场进行了数值计算,讨论了管壁后涡结构的脱落,同时分析了灰粒与受热面管壁的碰撞与磨损问题。认为随雷诺数的增加,漩涡脱落频率也随之增加,并得出二维流场向三维转捩的临界雷诺数为170~180。得出灰粒尺寸是影响碰撞频率和磨损率的一个主要因素,随粒径的增大,灰粒与壁面的碰撞频率呈指数增长。颗粒的冲击角度在20°左右颗粒对壁面的冲蚀率最大。
The direct numerical simulation is used to calculate the gas field and the particle field of the flue gas passing through the heated pipe, and the shedding of the rear vortex structure of the pipe wall is discussed. At the same time, the collision and wear of the ash and the heated pipe wall are analyzed . It is considered that with the increase of Reynolds number, the swirl shedding frequency also increases, and the critical Reynolds number of two-dimensional flow field to three-dimensional swirling is 170-180. It is concluded that the size of ash particles is a major factor affecting the collision frequency and wear rate. As the particle size increases, the collision frequency between ash particles and the wall increases exponentially. Particle impact angle of about 20 ° particles on the wall erosion rate of the largest.