Experimental study of the onset of nucleate boiling in vertical helically-coiled tubes  

立式螺旋管内过冷沸腾起始点实验研究（英文）

作　　者：Kong Lingjian Han Jitian Chen Changnian Liu Zhigang 孔令健;韩吉田;陈常念;刘志刚(山东省科学院能源研究所,济南250014;山东大学能源与动力工程学院,济南250061)

机构地区：[1]ZEnergy Research Institute of Shandong Academy Sciences,Jinan 250014,China [2]School of Energy and Power Engineering,Shandong University,Jinan 250061,China

出　　处：《Journal of Southeast University(English Edition)》2018年第3期402-407,共6页东南大学学报（英文版）

基　　金：The National Natural Science Foundation of China(No.50776055,51076084);the Natural Science Foundation of Shandong Province(No.ZR2016YL005)

摘　　要：The experiments of the onset of nucleate boiling using R134a as working fluid were conducted in vertical helically-coiled tubes. The experiments were carried out with a range of pressure from 450 to 850 kPa, inlet subcooling from 4.7 to 15.0℃, heat flux from 0.11 to 8.9 kW/m2 and mass flux from 218. 2 to 443. 7 kg/（ m2 · s ）. The heat flux, superheat and temperature undershoot at the ONB are analyzed in vertical helically-coiled tubes. Also, the effects of mass flux, system pressure, inlet subcooling and geometric parameters on the ONB are studied. The results demonstrate that the inception heat flux and superheat increase with increasing mass flux and inlet subcooling, but decrease with increasing system pressure and helix diameter. The pitch of the helical coil has a slight effect on the wall superheat and heat flux at the ONB. The correlation of heat flux at the ONB of subcooled flow boiling in helical coil is developed based on the experimental data, and it shows a good agreement with the experimental data.以R134a为工质,对立式螺旋管内过冷沸腾起始点进行了实验研究.实验参数范围为:压力450～850kPa,入口过冷度4. 7～15. 0℃,热流密度0. 11～8. 9 kW/m^2,质量流量218. 2 to 443. 7 kg/(m^2·s).对立式螺旋管内过冷沸腾起始点的热流密度、过热度和温度下降幅度进行了分析,研究了质量流量、系统压力、入口过冷度和螺旋管几何参数对过冷沸腾起始点的影响.实验结果表明:过冷沸腾起始点的热流密度和过热度随着质量流量和入口过冷度的增大而增大,但是随着系统压力和螺旋直径的增大而减小;螺旋节距对过冷沸腾起始点的热流密度和过热度的影响很小.基于实验数据提出了螺旋管内过冷沸腾起始点热流密度的关联式,且该关联式的预测精度较高.

关 键 词：two-phase flow subcooled flow boiling onset ofnucleate boiling helical coil 

分 类 号：TK121[动力工程及工程热物理—工程热物理]