固定管板式换热器的温度场数值分析

在对实际结构进行合理简化的基础上,以影响流动和传热的主要结构建立了某固定管板式换热器温度场数值计算模型,采用分段模拟、整体综合的方法,利用CFD软件Fluent对该换热器在正常操作工况下的流动与传热情况进行了数值模拟,得到了计算流道上有关各个构件的壁温场分布,并把主要结构CFD数值计算的结果与实测温度数据进行了对比。结果表明,CFD模拟模型数值分析得到的温度数据与实测数据相符,说明温度场的数值模拟分析方法及其流动条件的假定是符合实际的,计算参数选择是合理可行的。有关固定管板换热器中管束、管板和壳体的温度梯度变化情况的分析表明,尽管在它们的轴向、周向和径向都存在温度梯度,但是温度梯度变化最大的方向是轴向,这意味着轴向将产生最大热应力。

Numerical Analysis of the Temperature Field of Fixed Tube- Sheet Heat Exchangers

Based on the reasonably simplified actual structure,the numerical calculation model of the temperature field of a fixed tube-sheet heat exchanger was founded using the major structures that affected flow and heat transfer.A numerical simulation was made of the flow and heat transfer of the heat exchanger in a normal operating condition using the method of simulation in selections and comprehensive investigation and Fluent of Computational Fluid Dynamics(CFD)software,and the wall temperature field distribution of each structure in the computational flow channel.The result of numerical calculation of the major structures using CFD software was compared with the actual temperature data.The result shows that the temperature data obtained using the numerical simulation made with CFD simulation model agrees with actual testing data,the analysis method of the numerical simulation of the temperature field and the assumption of its flow condition conforms the actual condition,the selection of the calculation parameters is reasonable and feasible.The analyses of the changes of the temperature gradients of the tube bundles,tube-sheets,and shells in the fixed tube-sheet heat exchanger show that there are temperature gradients in their axial,circumferential,and radial directions,but the temperature gradient is most evident in the axial direction,it means that the most evident heat stress shall occur in the axial direction.