摘要
在压力22.5～30 MPa、质量流速1009～1626 kg/(m2.s)、内壁热流密度216～822 kW/m2的试验参数范围内,对均匀加热垂直上升光管内超临界压力水的传热特性进行了系统的试验研究,得到了不同工况下垂直上升光管内超临界水的传热特性,分析了压力、内壁热负荷和质量流速变化对光管内壁温度及换热系数的影响,并给出了能用于工程实际的传热试验关联式。试验结果表明:在拟临界点附近,光管壁温随焓值平缓增加,超临界水的换热系数显著增大,管内出现了明显的传热强化现象;在远离拟临界点的区域,光管壁温随焓值的增大显著升高,换热系数迅速减小;压力与热流密度的增大以及质量流速的减小,均会导致壁温升高,换热系数减小,传热强化减弱;随着热流密度的增大,换热系数峰值提前出现。
Within the range of pressure from 22.5 to 30 MPa,mass flux from 1009 to 1626 kg/（m2·s）,and inner wall heat flux from 216 to 822 kW/m2,an in-depth experiment was conducted under supercritical pressure to investigate the heat transfer characteristics of water in vertical upward smooth tube.The heat transfer characteristics of water under supercritical pressure were obtained in the experiment.The effects of pressure,inner wall heat flux and mass flux on the heat transfer coefficient and inner wall temperature were analyzed,the heat transfer mechanism was discussed,and the corresponding empirical correlations were also presented.The experimental results show that when the bulk fluid temperature is near the pseudo-critical temperature,the tube wall temperature increases slowly with the fluid enthalpy,the heat transfer coefficient gets larger abruptly and the heat transfer enhancement phenomenon occurs in the smooth tube.Otherwise,the tube wall temperature increases obviously with the increasing fluid enthalpy and the heat transfer coefficient is low.With the increase of pressure and inner wall heat flux,and with the decrease of mass flux,the inner wall temperature increases,the heat transfer coefficient decreases and the heat transfer enhancement is weakened.With the increase of inner wall heat flux,the maximum of heat transfer coefficient appears ahead.
出处
《核动力工程》
EI
CAS
CSCD
北大核心
2011年第1期75-80,共6页
Nuclear Power Engineering
关键词
超临界压力
光管
壁温
换热系数
传热强化
拟临界点
Supercritical pressure
Smooth tube
Wall temperature
Heat transfer coefficient
Heat trans-fer enhancement
Pseudo-critical temperature
