Abstract:

In order to make up the drawback of small gap modeling and analysis in current shell & tube heat exchanger numerical simulation on fluid flow and heat transfer，the full fluid flow and heat transfer mode，which contains the main flow stream of B，C and small leakage flow stream of A and E，is developed by the simulation method of “segmented modeling and comprehensive synthesis” that successfully incorporate the small leakage flow stream of A and E paths. The full fluid flow and heat transfer mode are consistent with the actual heat exchanger. The fluid flow and heat transfer is studied in the segmentation model by using CFD software；and the influence of these flow passages in the baffle space on the fluid flow and heat transfer are also discussed. Data of local flow and heat transfer from numerical simulation are further processed comprehensively to get the integrated correlation performance of heat transfer and pressure drop in heat exchanger. The numerical results are compared with several famous formulas，such as method of Donohue，Kern，Bell-Delaware and Flow Stream Analysis. It is shown that the simulation results are well agreed with Bell-Delaware and Flow Stream Analysis Method，the maximum deviation is less than 20%.

摘要：

针对目前管壳式换热器中微小流路建模和分析的缺失，采用“分段建模，整体综合”的模拟方法成功地开发了小间隙流路A和E的建模技术，建立了既包含主体流路（B、C），也包含微小泄漏流道（A、E）的全流路管壳式换热器流动与传热模型，得到了与实际换热器相适应的几何模型。通过应用CFD软件Fluent进行分段模型的流动与传热研究，对各流道在折流空间中对传热和流动的影响进行了分析讨论。同时，采用整体综合技术，将数值模拟获得的局部流动与传热数据综合整理得到了换热器传热和阻力系数的整体法关联式。并将模拟结果与几种著名的壳程计算方法（Donohue、Kern和Bell-Delaware，流路分析）进行了对比，结果发现数值模拟与Bell-Delaware法和流路分析法的结果吻合良好，最大偏差小于20%。