针对管壳式换热器折流板背部存在流动死区的问题,以低温油封冷却器为研究对象,采用计算流体动力学技术对低温油封冷却器折流板开孔后的整体性能进行机理研究。研究结果表明:折流板背部存在大量的旋涡是导致流动死区的直接原因,折流板开孔后能够形成垂直于折流板的射流,对流动死区有明显改善作用。折流板开孔后,壳程压降有较大的降幅,同时传热系数也有降低,但降低幅度远远小于降低幅度。在等换热面积和等压降情况下,折流板开孔冷却器传热系数可以提高10%。
Aim at the problem of the shell-and-tube heat exchanger existing stagnant zones at the back of baffle, take the low-temperature oil seal cooler as the object of research, numerical simulation was performed for the perforated bame based on CFD techniques. Results show that the directly reason of stagnant zones is that there exist a large amount of swirls at the back of baffles. The jet streams are perpendicular to the baffles when baffles are perforated, and have an obvious effect on stagnant zones. The decline of the shell pressure drop is great when baffles are perforated, meanwhile, the heat transfer coefficient also declined, but the declined magnitude are more less than the shell pressure drop. In the case of equivalent heat transfer area and pressure drop, the heat transfer coefficient of low-temperature oil seal cooler with perforated baffle can be increased by 10%.