中文摘要：

通过对不同螺旋角的螺旋折流板换热器壳程流体流动和传热进行研究,得出壳程进口未充分发展段的分布规律;并在考虑壳程结构特点的基础上,提出了一种新型变角度的螺旋折流板模型,改善壳程进口未充分发展段对换热器的影响。结果表明：换热器折流板的导流作用随着折流板螺旋角的增大而降低,螺旋角的增大使换热器壳程进口流体螺旋流动减弱,螺旋流动未充分发展段长度增加。变角度的螺旋折流板能够有效改善换热器壳程进口未充分发展段的作用,相同工况下通过优化变角度螺旋折流板α角,可使换热器壳程传热系数增加8.9%—9.1%,壳程压力损失增加5.8%—6.9%,综合性能增加6.6%—6.9%。计算结果为改进换热器螺旋折流板结构、强化换热器传热提供了理论依据。

英文摘要：

The fluid flow and heat transfer of helical baffles heat exchangers shell side were studied under three different helical angles,and the distribution rules of non-fully developed section in shell inlet were obtained. The characteristics of shell structure were considered. A new model of helical baffles with variable angles was presented and the impact of non-fully developed section on heat exchangers was improved by optimizing the baffle structures.The results show that the diversion effects of baffles decrease and the helical flow of shell inlet weaken with the increasing of helical angle. The length of non-fully developed section increases with the increasing of helical angle.The helical baffles with variable angles can effectively improve the effect of non-fully developed section in shell inlet. Under the same conditions,through the optimization of angle α for baffles,the heat transfer coefficient of shell-side increases by 8. 9%-9. 1%,the pressure drop increases by 5. 8%-6. 9%,comprehensive performance increases by 6. 6%-6. 9%. The results provide theoretical bases for the improvement of helical baffles structure and the enhancement of heat transfer.