流型转化对CO_(2)流动沸腾换热的影响研究  

Experimental Investigation on the Effect of Flow Pattern Transformation on CO_(2)Flow Boiling Heat Transfer

作　　者：黄永方 徐肖肖[1] 孙云龙 刘朝[1] HUANG Yongfang;XU Xiaoxiao;SUN Yunlong;LIU Chao(Key Laboratory of Low-grade Energy Utilization Technologies and Systems,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆大学低品位能源利用技术及系统教育部重点实验室,重庆4400044

出　　处：《工程热物理学报》2024年第6期1643-1649,共7页Journal of Engineering Thermophysics

基　　金：国家自然科学基金(No.52376001);重庆市自然科学基金(No.cstc2021jcyj-msxmX0795)。

摘　　要：本文开展了CO_(2)在内径5 mm水平光滑管内的流动沸腾换热及流型可视化实验,结合非绝热流型可视化数据对其流动沸腾换热特性开展研究。结果表明,受重力的影响,换热管顶部在低干度下发生间歇性干涸,导致其换热系数远低于底部换热系数。饱和温度的减小促进了流型的转换,有效减小间歇性干涸引起的管周向局部换热性能的差异,提高了截面的平均换热系数。饱和温度从15℃降至9℃时,截面平均换热系数提高约50%。In this paper,the flow boiling heat transfer and fow pattern visualization experiments of CO_(2)in a horizontal smooth tube with an inner diameter of 5 mm are carried out,and the fow boiling heat transfer characteristics are investigated in combination with the diabatic flow pattern visualization data.The results show that the top of the tube intermittent dry-out at low vapor quality with gravity,resulting in its heat transfer coefficient far lower than the bottom heat transfer coefficient.The reduction of the saturation temperature promotes the transition of the flow pattern,effectively diminishes the difference in local heat transfer of the tube caused by intermittent dry-out,and improves the average heat transfer coefficient.The average heat transfer coefficient is increased by approximately 50%when the saturation temperature is dropped from 15℃to 9℃.

关 键 词：二氧化碳 流动沸腾 流型可视化 沸腾换热特性 

分 类 号：TK124[动力工程及工程热物理—工程热物理]