垂直管内R124-DMAC鼓泡吸收过程流型演化可视化实验

Visual experiment on evolution of flow pattern of R124-DMAC bubble absorption process in vertical tube

通过搭建一套垂直管管内鼓泡吸收热、质耦合传递特性可视化实验平台,对以R124-DMAC(一氯四氟乙烷-二甲基乙酰胺)为工质的鼓泡吸收过程的流型特征与分布规律进行研究。结果表明,制冷剂气体流率、吸收溶液流率和进口温度对鼓泡吸收过程的流型及其分布规律均产生一定的影响。在制冷剂气体流率和溶液入口温度较高的情况下,鼓泡吸收过程存在搅拌流、弹状流、泡状流3种流型。制冷剂气体在吸收管内被完全吸收的条件下,搅拌流流型高度不超过总吸收高度(喷嘴出口到气泡消失的垂直距离)的1/2;弹状流流型所占总吸收高度的比例不超过2/5;其余的吸收高度为泡状流流型。

Through constructing a visual experiment platform of bubble absorption heat and mass coupled transfer characteristics in the vertical tube, the flow pattern characteristic and distribution regularity of bubble absorption process on R124/DMAC （2-chloro-1,1,1,2,-tetrafluoroethane/N＆#39;, N＆#39;-dimethylacetamide） as working medium are studied. The result shows that the flow pattern characteristic and distribution regularity are influenced by the refrigerant vapor flow rate, absorption solution flow rate and its inlet temperature. Under large refrigerant vapor flow rate and high solution inlet temperature conditions, three kinds of flow patterns of churn flow, slug flow and bubble flow can be simultaneously observed in the bubble absorption tube. Under the condition which the vapor is completely absorbed in the absorption tube, the height of churn flow is no more than half of the total absorption height, while the height of slug flow is no more than 2/5 of the total absorption height. The rest of the absorbing height is occupied by bubble flow.