纵流壳程换热器壳程近壁区流场和温度场数值研究

NUMERICAL RESEARCH ON FLOW FIELD AND TEMPERATURE FIELD OF SHELL SIDE NEAR-WALL REGION OF LONGITUDINAL SHELL-AND-TUBE HEAT EXCHANGER

对新型纵流壳程换热器壳程近壁局部区域的流场和温度场进行了数值模拟研究,总结了换热器横截面内各换热管壁面对流传热系数与换热管距壳体轴心距离的关系,分析了近壁区域非规则流道内流体对流传热系数较壳体中心主流区内规则流道大的原因,为换热器壳程内关键局部区域流体流动和传热状况的改善以及进一步的结构优化提供了直观依据。提出的纵流壳程换热器周期性全截面计算模型,为发现和解决换热器中与局部位置流体流动和传热细节相关的深层次问题提供了良好的辅助手段。

Numerical simulation is carried out on the local flow field and temperature field of the near-wall region in the shell side of new type longitudinal shell-and-tube heat exchanger, the relationship between surface heat transfer coefficient of all tubes in cross section of heat exchanger and the distance from tubes to axis of the shell is summarized, and reasons why the convection heat transfer coefficient in the non-regular ducts in the near-wall region is higher than that in the regular ducts in the centeral main flow region is also analyzed, which can provide the intuitionistic base for improving the flow and heat transfer performance of the fluid in key local region and for the further structure optimization of heat exchangers. The ＂Periodic Whole Cross-Section Computation Model＂ of longitudinal shell-and- tube heat exchanger is proposed and adopted, which provides well aided method for the discovery and solution of deep problems concerned with local fluid flow and heat transfer details of the shell-and-tube heat exchanger.