缠绕管式换热器的CFD优化

用ANSYS CFX软件采用基于有限元的有限体积法对简化的缠绕管式换热器的壳程流动进行模拟，考察管束导程和壳程流速等参数对缠绕管式换热器壳程流体流动特性的影响。结果表明，减小缠绕管束的导程可提高壳程流体的湍流程度，增强壳程流体的均匀程度，减少温度死区并提高换热效率，减小同一截面不同区域的压力差，进而减小因流场不均匀而对管束产生的破坏性应力。提高壳程流速可增强换热，但会增加壳程压降。

CFD optimizations of spiral-wound heat exchangers

As a new kind of efficient and compact heat exchange equipment, spiral-wound heat exchangers which has the characteristics of high heat transfer efficiency, high degree of intensification, less floor space and so on can realize heat transfer among multiple logistics. These advantages can decrease the overall investment. Although many scholars have studied the spiral-wound heat exchangers by numerical simulation, the effects of every operating parameter on the flowing and heat transferring in the shell domain still need to be studied deeply. In this work the shell fluid field of a simplified spiral-wound heat exchanger was simulated by finite volume method based on finite element method with the commercial software ANSYS CFX. By changing the helical leads of spiral tubes and shell inlet velocities, the flow characteristics and heat transfer performance of the shell fluids in spiral-wound heat exchangers were discovered. What is more, some beneficial reference basis was provided for the optimization designs of the spiral-wound heat exchangers. The results showed that the less the helical leads of spiral tubes in the spiral-wound heat exchangers, the higher vorticity and turbulence of the shell fluid domain, the less the temperature dead zone, the better the heat transfer performance between the shell fluid domain and tube fluid domain. Furthermore, reducing the helical leads of spiral tubes in the spiral-wound heat exchangers could make the pressure distribution in the shell fluid domain more balance, which reduced the damage caused by the pressure difference between different regions in the shell fluid domain. Increasing the inlet velocity of shell fluid field was beneficial to enhance heat transfer performance between the shell fluid domain and the tube fluid domain, the pressure drop between the inlet of the shell fluid domain and the outlet of the shell fluid domain increased.