斜向流换热器壳程流场均匀化研究

Research on Flow Field Homogenization in Shell Side of Sidelling Flow Heat Exchanger

传统弓形折流板换热器壳程流体横向流动时存在流动阻力和传热死区大等缺点。为克服上述不足,研究开发了一种新型高效节能的斜向流管壳式换热器,采用导向型折流栅替代传统弓形折流板,倾斜流道内流体斜向冲刷换热管束。考察和对比了斜向流换热器和弓形折流板换热器壳程主流区的流体流速分布和变化规律,证实了导向型折流栅具有显著的控涡均化壳程流场和提高壳程流体整体流速的作用,有助于减小壳程压降,增大有效换热面积,为管壳式换热器结构改良提供了参考依据。

There are some disadvantages in the traditional segmental baffle heat exchanger for the transversal fluid flow in its shell side,such as the high flow resistance,large heat transfer dead region, and so on.For overcoming those above disadvantages,a kind of new efficient and energy saving shell-and-tube heat exchanger with sidelling flow in shell side is developed,the traditional segmental baffles are substituted by leading type shutter baffles,therefore,the fluid in some local regions flows over tubes inclinedly.The velocity distribution and velocity variation at the same position of main flow region in sidelling flow heat exchanger and segmental baffle heat exchanger is studied and compared.It is confirmed that,with the leading type shutter baffles in shell side,the vortex in shell side is weaken,flow field is greatly homogenized,and the velocity in shell side is increased.Shutter baffles are helpful to reduce the pressure drop in shell side and increase effective heat transfer area, which provides references for structure improving of shell-and-tube heat exchanger.