【摘要】 为研究壳程多通道管壳式换热器中并列分置管束长宽比锐减对其内部速度场及深度换热性能的影响,抽取具有代表性的单元流路区域建立并列分置管束模型。对长宽比范围在1.85～9.23、传热管数目分别为10,20,30,40和50的5个并列分置管束模型应用FLUENT软件进行了数值模拟。研究结果表明:当管程与壳程轴流段平均速度均为10 m/s时,随长宽比锐减,并列分置管束换热性能下降且壳程阻力显著增加,壳程流体速度分布越来越不均匀。在典型工况下,长宽比大于4.62的并列分置管束中冷流体出口温度高于热流体出口温度,即可以实现深度换热,在长宽比小于3.08的并列分置管束模型中不能实现深度换热。这为壳程多通道管壳式换热器的结构设计提供参考依据。更多还原

【Abstract】 In order to investigate the effect of ratio of length to width(L/W) decrease on velocity distributions and deep heat transfer performances in tube bundles in multi-parallel-channel(MPC) shell-and-tube heat exchangers(STHXs),tube bundle model was formulated based on a classical flow channel unit.Numerical investigation was carried out for five tube bundle models with tube numbers of 10,20,30,40 and 50 for L/W ranging from 1.85 to 9.23,respectively.The computations were carried out using FLUENT,a commercial CFD code.The simulation results show that when axial average velocity is 10 m/s both in the shell side and the tube side,outlet temperature of cold air is bigger than that of hot one,that is,deep heat transfer performance can be achieved in tube bundles with L/W bigger than 4.62,and deep heat transfer performance can not be achieved in tube bundles with L/W smaller than 3.08.A powerful reference for optimal design of multi-parallel-channel STHXs is provided by the results.更多还原