内旋流流化床颗粒运动的研究

A Study of the Particle Movement in an Internal Circulating Fluidized Bed

内旋流流化床供风的速度较低，颗粒的流动属于稠密气固两相流，利用通常的测量手段研究内旋流流场，尤其是颗粒的速度场存在一定的困难。由于内旋流流化床是一种近似二维床，可以利用瞬态平面二维速度场测量技术（ＰＩＶ和ＤＰＩＶ） 测量流化床某一断面的颗粒流场。对实验室原有的ＤＰＩＶ系统进行了改进，并用该系统初步研究了内旋流流化床颗粒运动的速度场。结果较好地描述了颗粒的二维流动。

Under a relatively low air feed speed the particle flow of an internal circulating fluidized bed (ICFB) pertains to a dense gas solid two phase one. There exist some difficulties in studying the internal circulating flow field, especially the particle velocity field, in case conventional measuring devices are used. As the internal circulating fluidized bed approximates a planar fluidized one, it is possible to utilize the measuring technique of transient planar two dimensional velocity field (PIV and DPIV) to measure the particle flow field of a certain section of the ICFB. An improved version of the existing DPIV (digital particle image velocimetry) in the lab has been employed to conduct a preliminary research of the velocity field of the ICFB particle movement. This has led to a better understanding and characterization of the particle two dimensional movement.