三种管壳式换热器传热与流阻性能对比实验研究

弓形折流板换热器壳程流体横向冲刷换热管时存在流动阻力大和传热死区大等缺点,折流杆换热器壳程流体纵向流动,但当壳程流体雷诺数Re较小时传热性能不佳。为克服上述缺点,研究开发了一种新型高效节能的斜向流管壳式换热器,该换热器壳程流体总体呈纵向流动,局部区域流体倾斜冲刷换热管束。对斜向流换热器与折流板换热器和折流杆换热器传热与流阻性能的对比实验研究表明,在同等壳程流体流量下,斜向流管壳式换热器的传热系数、压降和综合性能均介于折流板换热器与折流杆换热器之间。研究结果为管壳式换热器升级换代提供了一种新技术和新装备,也为热力系统中换热器选型和结构优化设计提供了重要依据。

Contrast Experimental Research on Heat Transfer and Flow Resistance Performance for Three Kinds of Shell-and-tube Heat Exchangers

There are some disadvantages in segmental baffle heat exchanger for the transversal flow over tubes in its shell side,such as the high flow resistance,large heat transfer dead region,and so on.The fluid flows longitudinally in the shell side of rod baffle heat exchanger,but the heat transfer performance is not perfect when the Reynolds number in shell side is low.For overcoming above mentioned disadvantages,a kind of new efficient and energy saving shell-and-tube heat exchanger with sideling flow in shell side was developed,the fluid flowed longitudinally in general,and the fluid in some local regions flowed over tubes inclinedly.Contrast experiments on heat transfer and flow resistance performances among this new kind of heat exchanger and segmental baffle heat exchanger,rod baffle heat exchanger were carried out,it is indicated that with the same fluid flow in shell side,the heat transfer coefficient,pressure drop,and over-all performance of sideling flow heat exchanger lie in between of those of segmental baffle heat exchanger and rod baffle heat exchanger.With this new kind of heat exchanger,the new technique and products are provided for the upgrade and update of shell-and-tube heat exchanger,and the important basis are also provided by research results for the structure selection and optimization design of heat exchangers in thermal system.