摘要
对含不凝气体的蒸汽掠过椭圆管外,伴随凝结发生的传热传质现象进行了数值模拟。研究了等周长椭圆管长短轴比（a/b=1.0~4.0）、工质进口速度（v）以及蒸汽质量分数（Y_v）对凝结传热及复合传热的影响。研究发现,当a/b为1.0时,凝结传热最强,随着a/b增大,椭圆管外凝结换热系数有所降低;当椭圆长短轴比为4.0时,约下降20%;椭圆管外的平均凝结换热系数随着进口速度和蒸汽质量分数增大而增大。
Deal with the problem of heat and mass transfer with vapor condensation in the presence of non-con- densable gas outside of isothermal elliptical pipe cross-section placed in a uniform stream, the effect of its major to minor axis ratio（a/b） on the heat transfer process in the range of approaching velocity （v） from 3 to 10 m/s and vapor mass fraction （ Yv ） from 0. 03 to 0. 3 is studied. The study reveals that the condensation heat transfer coeffi- cient of elliptical pipe is decreased, compared with round pipe with same perimeter, for the case of a/b equal to 4. 0, it decreases by 20%. The results also show that higher value of v or Yv gives higher heat transfer rate when a/b remains constant. The effect of ratio of a/b on local heat transfer coefficient for condensation of steam around periphery of ellipse is plotted and this effect on the overall rate of heat transfer is briefly discussed, aim to provide refer- ence for the related research and application.
出处
《科学技术与工程》
北大核心
2016年第5期71-76,共6页
Science Technology and Engineering
基金
国家自然科学基金(51476108)
山西省自然科学基金(2012001024-4)资助
关键词
凝结换热
不凝气体
椭圆管
数值模拟
condensation heat transfer non-condensable gas elliptical pipe numerical simulation
