带防冲板管壳式换热器入口流场数值模拟研究

Numerical Simulation of Inlet Flow Field of Shell and Tube Heat Exchanger with Scour Plate

换热器在化工、石油、热能动力等许多工业领域中应用十分广泛,其中管壳式换热器经常由于流体诱导振动发生破坏,为防止入口处高速流体直接冲刷换热管导致破坏,需在入口处加装防冲板。由于加装防冲板导致壳程流场更加复杂,从而是否导致了换热器的管束流致振动,因此开展带有防冲板管壳式换热器入口壳程流场研究具有重要意义。本文以化工生产中某一管壳式换热器为研究对象,采用计算流体力学(CFD)方法建立入口壳程流场数值计算模型,研究在加装防冲板情况下,不同管束排布条件流场的分布特点。数值模拟结果表明,在正三角形排布方式下,靠近壳体的外排管束受到的扰动最大,但正方形排布方式下的流场分布与其不同,受到最大扰动的为靠近壳体的内排管束。并且数据显示,在正三角形排布方式下,靠近壳体的外排管束受到的扰动最大,但正方形排布方式下的流场分布与其不同,受到最大扰动的为靠近壳体的内排管束。

The heat exchanger is widely used in many industrial fields, such as chemical industry, petroleum, thermal power, and so on. The shell and tube heat exchangers are often damaged due to fluid-induced vibration. In order to prevent the high-speed fluid from directly flushing the entrance, it is supposed to install the defending wave board at the entrance. We need a specific analysis, because the shell flow field is more complex, and even causes flow-induced vibration of the tube as a result of the installation of the defending wave board. Therefore, it is very important to carry out the study of the flow field of the inlet shell with defending wave board in the shell and tube heat exchangers. In this paper, a special type of shell and tube heat exchanger in chemical production is taken as the research object. The Computational Fluid Dynamics method (CFD) is used to establish the model of the inlet shell flow field. The paper studies the distribution characteristics of flow field under the installation of the defending wave board. The data obtained by numerical simulation show that the divergence of the outer tube bundle near the shell is the largest in the triangular arrangement, but the distribution of the flow field in the square arrangement is different from that of the casing tube bundle. Therefore, the significance of this research is to explore a new research system that can describe the relationship between different arrangements, different flow rates, and the characteristics of different flow fields. Try to offer some structure design ideas for defending wave board shell and tube heat exchanger. And the data show that the outer tube bundles close to the shell are the most disturbed in the equilateral triangle arrangement, but the flow field distribution is most disturbed in the square arrangement, where the inner tube bundles close to the shell.