【摘要】 针对一种桨栅呈辐状式分布的冷却塔用新型水轮机,设计出一种适用于该水轮机的特型蜗壳,该蜗壳在结构上首次采用由圆形截面向椭圆截面过渡的轴向出水方式,这种设计不仅能有效节省冷却塔内部空间,同时也具备良好的引水性能。蜗壳设计采用了理论分析和CFD数值模拟计算相结合的方法,根据蜗壳纵向断面压力和速度分布图得出其断面处的压力和速度分布规律;结合蜗壳出口处速度矢量图,分析出口环面上标称圆圆周速度、随机点轴向速度和圆周分速度矩的分布特点。结果表明,该蜗壳的水力性能与理论设计相符,具有很高的实用价值。更多还原

【Abstract】 Aiming at a new type of hydraulic turbine of cooling towers which paddle bars are distributed in a radial pattern,this paper designs a special volute for the turbine. The volute applies the axial drainage outlet transitioning from circular section to elliptical section for the first time,which can not only save the interior space of the cooling tower effectively but also have good performances of the diversion. In this paper,theoretical analysis and CFD numerical simulation are used to design the volute,obtaining the distribution law of the pressure and velocity at the section according to the pressure and velocity distribution diagram of the longitudinal section of the volute. Based on the velocity vector diagram at the volute outlet the distribution characteristics of the nominal peripheral speed,axial velocity of random points and circumferential component of velocity moment on the torus of outlet are analyze. The results show that the hydraulic performance of the volute is consistent with the theoretical design and it has high practical value.更多还原