摘要
为有效解决降膜蒸发器加热管中传热效率与结垢问题,提出了一种降膜蒸发管内插往复螺旋强化传热技术,强化管内插螺旋运动与管壁碰撞过程。实验研究内插螺旋的结构参数、螺旋往复行程,以及热通量、蒸发压力以及溶液喷淋密度等工艺参数对降膜蒸发过程传热性能影响。实验结果表明,此技术的除垢防垢性能及传热性能优于空管及单纯的内插螺旋性能,在螺旋外径d=30 mm、螺距f=45 mm、丝径e=1.8 mm、往复行程H=100 mm时,其传热系数分别是空管和单纯的内插螺旋的2.08和1.26倍。通过对管内蒸发侧传热系数进行分析,总结得到与热通量、蒸发压力以及溶液喷淋密度相关的降膜蒸发传热系数关联式。
In order to effectively solve the problems of heat transfer and fouling in the heat exchange tube,a new heat transfer enhancement technique with reciprocating spiral-inserts in falling film evaporator tubes was proposed.It can improve the spiral movement inside the tubes and the collision situation between the spiral and tube wall.The influences of the structure parameters and the reciprocating stroke of the spiral,the process parameters such as the heat flux,the evaporation pressure and the fluid spraying density on the heat transfer performance of the falling film evaporation process were studied experimentally.The results show that the anti-fouling effect and heat transfer performance of the proposed technique are better than those of empty tube and simple spiral-insert.With the spiral outer diameter 30 mm,pitch 45 mm,wire diameter 1.8 mm and the reciprocating stroke 100 mm,the overall heat transfer coefficient is 2.08 times and 1.26 times of that of empty tube and the tube with simple spiral-insert respectively.The correlation of falling film evaporation heat transfer coefficient related to heat flux,evaporation pressure and spraying density are obtained through further data analysis.
作者
彭德其
侯家鑫
陈康
吴淑英
俞天兰
Peng Deqi;Hou Jiaxin;Chen Kang;Wu Shuying;Yu Tianlan(School of Mechanical Engineering,Xiangtan University,Hunan Xiangtan 411105,China;School of Mechanical Engineering,Hunan University of Technology,Hunan Zhuzhou 412007,China)
出处
《化学工业与工程》
CAS
CSCD
2020年第4期15-22,共8页
Chemical Industry and Engineering
基金
湖南自然科学基金(2018JJ4054)。
关键词
降膜
蒸发
传热
结垢
往复螺旋
falling film
evaporation
heat transfer
fouling
reciprocating spiral
