带小肋片的大小孔弓形折流板换热器的流动与传热研究

Study on Flow and Heat Transfer of Large-and-Small-Hole Segmental Baffle Heat Exchanger with Small Fins

大小孔弓形折流板换热器能减少板后流动死区、降低压降,但对壳程的强化传热效果不明显。而纵向涡发生器能使流体产生强烈的扰动,在实现强化传热的同时流动损失也较小。针对这一情况,提出大小孔弓形折流板耦合纵向涡发生器的换热器结构,此时的纵向涡发生器称之为小肋片。构建带小肋片的大小孔弓形折流板换热器模型并利用ANSYS-Fluent软件对该结构进行数值模拟,对3种不同结构的小肋片进行了流动和传热性能对比分析研究。结果表明,小肋片为小矩形翼阵列对齐布置时,换热器换热性能相对于大小孔弓形折流板换热器传热性能要高,但大小孔弓形折流板换热器的综合性能最高。

The heat exchanger with large-and-small-hole segmental baffles can reduce the flow dead zone and the pressure drop,which behind the baffle,but the heat transfer enhancement effect on the shell side is not obvious.The longitudinal vortex generator can make the fluid produce strong disturbance,which can enhance the heat transfer and reduce the flow loss.Given this situation,the heat exchanger structure of large-and-small-hole segmental baffles coupled with longitudinal vortex generators is proposed,and the longitudinal vortex generators are called small fins.The model of the heat exchanger with small fins and large-and-small-hole segmental baffles was built and the structure was numerically simulated by ANSYS-Fluent software.The thermal-hydraulic performance of three kinds of small fins with different structures was compared and analyzed.The results show that when the small fins are arranged in alignment with the rectangular wing array,the thermal performance of the heat exchanger is the highest,compared with the segmental baffle heat exchanger with large-and-small-hole.The comprehensive performance of the large-and-small-hole segmental baffle heat exchanger without small fins is the highest.