水滴形管换热与阻力特性的数值研究

为提高换热管的综合性能,设计并研究了一种新型水滴形换热管,采用CFD软件,在相同管横截面积的前提下,对圆形、椭圆形及水滴形换热管单管和管束的换热与阻力特性进行了模拟计算。研究表明:水滴形管可以明显减小换热管背流面的回流;在相同的进口流速下,水滴形管管束努塞尔数Nu较圆管和椭圆管分别增大了28%和18. 5%,而进出口压降相较于椭圆形及圆形管分别减小了45. 5%及90%,相较于圆形管及椭圆形管,水滴型管具有更好的换热流动特性。

Numerical Simulation on the Heat Exchange and Flow Resistance of Water Drop-shaped Tube

In order to improve the comprehensive performance of heat exchanger tubes,a water drop-shaped heat transfer tube has been developed.The CFD software is used to simulate the heat transfer and flow resistance of single tube and tube bundles of circular,elliptical and water-drop shapes under the same cross-sectional tube area.The results show that the water drop-shaped tube can reduce the recirculation zone of the flue gas outside the pipe.Compared to the circular and elliptical tubes,the Nusselt number of the droplet tube is increased by 28% and 18.5%,while the pressure drop is reduced by 45.5% and 90%,respectively.It indicates that the water droplet type tube has better heat exchange and flow characteristics than the circular and elliptical tubes.