5 mm微肋管内R404A流动沸腾换热特性研究  

Study on the Flow Boiling Heat Transfer Characteristics of R404A in 5 mm Micro-fin Tube

作　　者：余肖霄 柳建华[1] 何宽 王皓宇 YU Xiao-xiao;LIU Jian-hua;HE Kuan;WANG Hao-yu(Key Laboratory of Multiphase Flow and Heat Transfer in Shanghai Power Engineering,University of Shanghai for Science and Technology,Shanghai,China,200093)

机构地区：[1]上海理工大学上海市动力工程多相流动与传热重点实验室

出　　处：《热能动力工程》2019年第11期82-88,共7页Journal of Engineering for Thermal Energy and Power

基　　金：上海市部分地方院校能力建设专项计划(16060502600)~~

摘　　要：通过实验研究了R404A在5 mm微肋管内的流动沸腾换热特性。热流密度为5~25 kW/m^2、质量流速为200~500 kg/(m^2·s)、饱和温度为-5~5℃、干度为0.1~0.9。结果表明:提高饱和温度可以提高换热系数,在0.1~0.3低干度区提升作用较为明显,在0.3~0.6中干度区提升作用逐渐降低;随着质量流速的增大,换热系数呈上升趋势,其对换热系数的影响主要体现在中干度区;热流密度的增大也能够有效提升换热系数,同时使换热系数的峰值提前出现,加速干涸现象的发生。针对本实验数据,修正后的Gungor模型预测精度较高,修正系数为1.372,统计得出平均绝对偏差仅9.30%,高达98.18%的数据偏差度小于±30%。The characteristics of heat transfer for R404 A flow boiling in horizontal 5 mm micro-fin tube were studied.Experimental conditions: heat flux 5~25 kW/m^2,mass flux 200~500 kg/(m^2·s),saturated temperature-5~5 ℃,vapor quality 0.1~0.9.The experimental results show that increasing saturation temperature can improve the heat transfer coefficient,which is obvious in the low dryness range from 0.1 to 0.3,and gradually decreases in the middle dryness range from 0.3 to 0.6.Increasing mass flow rate can increase the heat transfer coefficient in the middle vapor quality mainly.The increase of heat flux has significant effect on enhancing nucleate boiling heat transfer,meanwhile decreases the vapor quality for peak of heat transfer coefficient and speeds up the dryout process.Compared with the prediction model,the modified Gungor′s model has higher prediction accuracy with a correction coefficient of 1.372.It is presented with 98.18% of predicted points within ±30% and 9.30% mean absolute deviation.

关 键 词：流动沸腾 小管径 换热系数 换热模型 R404A 

分 类 号：TK124[动力工程及工程热物理—工程热物理]