管壳式换热器动态特性数值仿真

应用有限差分法对顺流及逆流管壳式换热器动态特性进行了数值预测，计算模型考虑了壳侧流动不均匀性、流体轴向扩散效应及固壁轴向导热对动态特性的影响。采用隐式差分格式进行计算，研究了当进口流量及温度同时发生扰动时换热器温度等参数的动态响应以及换热器壁面比热容和导热系数对其动态响应的影响规律。结果表明，增大比热容能够增加温度响应的上升时间，增大换热器壁面的导热系数能够提高管侧出口的平均温度。

Numerical Study on Convective Heat Transfer and Pressure Drop of Corrugated Tube

The dynamic behavior of two different kinds of shell-and-tube heat exchangers：parallel-flow and counter-flow,were investigated numerically by finite difference method （FDM）. The computational model took the following factors into consideration such as longitudinal conduction of fluid and longitudinal conduction of solid wall. Implicit FDM was adopted to calculate the corresponding outlet temperature of heat exchanger when inlet flow rate and temperature varied at the same time. Moreover,Influence of longitudinal heat conduction and specific heat of solid wall on dynamic behaviors were studied, it is found that ascend time of temperature would increase with the specific heat and the exit temperature of tube side would increase with longitudinal heat conduction.