管壳式换热器的热流固耦合数值分析

Numerical Analysis of Thermal Fluid Structure Coupling in Shell and Tube Heat Exchangers

为了研究列管式换热器在工作过程中由于壳程内温差过大导致的热应力梯度问题,以换热器固体域和内部流体域为研究对象,基于SIMPLE算法,建立三维管壳式换热器稳态运行模型。通过换热器内部的温降和压降结果分析,对换热器进行热流固耦合计算,通过研究流体动力学特性以及管壳式换热器筒体、折流板、换热管等结构的温度和压力分布特点,分析换热器结构的热应力分布情况,在此基础上对典型换热器进行了形变分析。结果表明:换热器产生的应力变化主要是由温度场引起,换热管与管板的连接处应力最大,产生形变的主要位置在壳程入口以及换热器外壁上,通过对换热器应力进行评定,指出该换热器在模拟环境中是安全可靠的。研究结果为其进一步研究奠定了基础。

In order to study the thermal stress gradient problem caused by excessive temperature difference in the shell side during the operation of a tube and tube heat exchanger,a three-dimensional steady-state operation model of the tube and tube heat exchanger was established based on the SIMPLE algorithm,taking the solid and internal fluid domains of the heat exchanger as the research objects.By analyzing the temperature drop and pressure drop results inside the heat exchanger,the heat flow structure coupling calculation was carried out,and the fluid dynamics characteristics and temperature and pressure distribution characteristics of the shell and tube heat exchanger cylinder,baffle plate,heat exchange tube,and other structures were studied.The thermal stress distribution of the metal structure of the heat exchanger was analyzed,and based on this,deformation analysis on a typical heat exchanger was carried out.The results showed that the stress changes generated by the heat exchanger were mainly caused by the temperature field.The stress at the connection between the heat exchange tube and the tube sheet was the highest,and the main locations for deformation were at the shell side inlet and the outer wall of the heat exchanger.Through corresponding stress assessment,it was concluded that the heat exchanger was safe and reliable in the simulated environment.The research results laid the foundation for further research.