An experimental study of annular film flow condensation in a micro-fin tube with high mass flux
An experimental study of annular film flow condensation in a micro-fin tube with high mass flux
复制标题
DOI：
10.1016/j.ijrefrig.2024.01.024
复制
发表时间：
2024-01
影响因子：
3.9
通讯作者：
Qingpu Li;Xiangqi Meng;Lei Li;Neng Gao;Nian Li;Rui Qiu
中科院分区：
文献类型：
--
作者：
Qingpu Li;Xiangqi Meng;Lei Li;Neng Gao;Nian Li;Rui Qiu
在500-1100 kgm-2s-1的质量通量条件下，对R134a在4个水平微翅片管内的环形液膜和流动冷凝换热进行了实验研究。试验管在几何上的最大差异本质上是管径和翅片螺旋角。首先通过液膜变化揭示了质量通量、蒸汽质量、饱和温度、翅片螺旋角、管径等对传热性能的影响机理。换句话说，换热系数随实验变量的变化规律可以进一步用液膜厚度和流量的变化来解释。随后，将测量的传热系数与一些现有相关性的计算值进行了比较。经验证，研究报告的相关系数均低估了高质量通量下的换热系数，实验变量尤其是质量通量和蒸汽质量对相关预测精度影响较大。因此，为了实现对传热系数的高精度预测，在对液膜内的连续性、动量和能量过程进行理论分析的基础上，提出了一种新的关系式，该关系式对实验数据的预测平均偏差为1.61%。
In the work, the annular liquid film and flow condensation heat transfer of R134a inside four horizontal micro-fin tubes were experimentally studied under mass fluxes of 500–1100 kgm-2s-1. The biggest difference of the tested tubes in geometry is essentially tube diameter and fin helical angle. The influencing mechanisms of mass flux, vapor quality, saturation temperature, fin helical angle, tube diameter, etc., on the heat transfer property were firstly revealed through the liquid film variation. In other words, the transformation rules of the heat transfer coefficient with the experimental variable can be further explained by the liquid film thickness and flow variations. The measured heat transfer coefficients, subsequently, were compared with the calculated values of some existing correlations. After verification, all correlations reported in the researches underestimate the heat transfer coefficient at high mass flux, and the experimental variables, particularly mass flux and vapor quality, have a great effect on the correlation prediction accuracy. To achieve a high-accuracy prediction for the heat transfer coefficient, therefore, on the basis of the theoretical analysis of the continuity, momentum and energy processes in the liquid film, a new correlation was proposed and it can predict the experimental data with an average deviation of 1.61 %.