基于Matlab的管壳式换热器分段计算研究

摘要

In this paper, on the basis of the baffle plates, a shell and tube heat exchanger is divided into certain cells, and though the study of each cell, the process design and calculation of shell and tube heat exchanger with temperature dependent thermal properties are studied. What’s more, a much more accurate method is put forward for the tube shell heat exchanger to calculate the wall temperature both of the shell and tube side which bases on the differentiation. According to a case analysis, the mean error which separately compared with the HTRI’s in the both of shell and tube sides are 0.94% and 1.76%, which demonstrates the feasibility of the wall temperature calculation method. And from the results compared with the HTRI’s on the heat transfer coefficient and pressure drop, we can conclude that the computed result with variable properties is better than the fixed properties. With the aid of Matlab computer software, a whole set of procedures are compiled for the shell and tube heat exchanger segmented calculation and optimization design, which not only contributes to realizing the precise optimization design but also improving the calculation efficiency, and variable property research theory provides a certain way for efficient and low energy consumption heat exchanger design, it is of certain value for engineering application.%以折流板结构为基础将管壳式换热器分成一定的计算单元，通过对每个分段单元的研究，从流体物性沿壳体方向变化方面来对管壳式换热器进行整体的工艺设计及计算。并且基于微分法，提出了一种较为准确预测出管壳式换热器管、壳侧壁温分布的方法。通过工程案例分析，并将壁温计算结果与HTRI进行对比得出，管、壳程各单元的壁温平均误差分别1.76%和0.94%，该结果也验证了壁温计算方法的可行性。对于传热系数与压降，与 HTRI 对比得出：变物性计算较定物性在精度有一定的提高。同时通过借助Matlab计算机软件编制了一套用于管壳式换热器分段计算及优化设计程序，实现了换热器的精确优化设计的同时也提高了计算效率，变物性的研究理论为高效低能耗换热器的设计提供了思路和方法，具有一定的工程应用价值。