气固两相流绕流螺旋翅片管的实验研究

Experimental Study on Gas-Solid Flow around Spiral Finned Tube

应用三维颗粒动态分析仪(PDA)对气固两相流绕流螺旋翅片管进行了实验研究.实验采用的颗粒为玻璃飘珠,对翅片间的速度和颗粒密度分布规律进行了测量.结果表明:在翅片之间,固相颗粒密度分布呈抛物线形规律性分布,即在远离翅片的中心区域颗粒密度较大,离两侧翅片较近的区域颗粒密度逐渐减小,近翅片区域颗粒密度要比中心区域小很多;主流速度也呈现类似规律.颗粒密度和速度的这种分布规律降低了固体颗粒对翅片壁面的撞击能量,从而减轻了翅片和基管的磨损.实验数据表明,螺旋翅片的导流作用使得迎风面的滞点处产生了轴向速度,这和光管有着本质的区别.

The gas-solid two-phase flow around a spiral finned tube was measured using a three dimensional particle dynamic analyzer （PDA）. The particles used were glass beads. A parabolic distribution of the particle concentration and velocity between two adjacent fins was observed. The results show that the concentration and velocity in the center zone are relatively high. Moreover, the closer the zone is to the wall, the lower the values are. This parabolic distribution of velocity and concentration abates the collision energy against the base pipe and the fins. Thus the abrasion is alleviated. In addition, an axial velocity is observed at the windward stagnant point because of the guidance of the spiral fins, which is essentially distinct from bare tubes.