摘要
为探讨热管最佳工况,搭建了适用于多年冻土区的氨-钢热管试验台。通过监测热管内部轴向、外壁的温度分布以及外壁面的热流密度变化,在负温条件下开展了不同充液率(20%、30%、40%)和倾角(10°、30°、50°、70°、90°)对热管传热性能影响的试验。试验结果表明:在三种充液率下,热管处于10°倾角时均温性最佳;充液率为30%和40%的热管倾角50°时总热阻最小、传热效率最高,充液率为20%条件下热管的总热阻和传热效率在倾角30°时分别达到极小值和最高值。总体而言,充液率为30%的热管具有最佳传热表现。
Two-phase closed thermosyphons(TPCTs)play a significant role in permafrost regions due to their thermal semiconductor effect.Many TPCTs have been used to collect cold energy from the ambient air in permafrost regions to cool the underlying stratum.In this study,an ammonia-steel TPCT test bench suitable for permafrost regions was built to optimize the working conditions of the TPCT.The effects of filling rate and inclination angle on the heat transfer performance of low-temperature TPCTs were analyzed.Experiments were carried out at different filling rates(20%,30%,40%)and inclination angles(10°,30°,50°,70°,90°)under negative temperature conditions.To simulate low-temperature conditions,the ambient temperature difference between the evaporator section and the condenser section was set to 13℃.The heat transfer performance of the TPCT was evaluated based on the temperature distribution inside and outside the TPCT and the variation in the heat flux density of the outer wall.The heat transfer performance of the TPCT was evaluated using indexes such as isothermal characteristics,thermal resistance,and transfer efficiency.The experimental results show that,under three experimental filling rates,all TPCTs with an inclination angle of 10°have the best axial internal isothermal performance.The minimum thermal resistance occurs at an inclination angle of 50°when the TPCT filling rates were 30% and 40%,corresponding to the highest heat transfer efficiency.For the TPCT with a filling rate of 20%,the minimum thermal resistance and the highest heat transfer efficiency both occur at an inclination angle of 30°.Overall,the TPCT with a filling rate of 30% has the optimal heat transfer performance.It is recommended that the inclination angle of TPCTs is between 10°and 50°.This study provides meaningful reference for the best structural parameters in the design of TPCTs for cold regions engineering.
作者
王英梅
王茜
王俊程
马殷军
徐安花
刘永恒
陈继
WANG Yingmei;WANG Xi;WANG Juncheng;MA Yinjun;XU Anhua;LIU Yongheng;CHEN Ji(College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Beiluhe Observation and Research Station on Frozen Soil Environment and Engineering Environment/State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;Key Laboratory of Complementary Energy System of Biomass and Solar Energy,Lanzhou 730050,China;China Railway Qinghai-Tibet Group Co.,Ltd.,Xining 810007,China;Qinghai Communications Technical College,Xining 810003,China)
出处
《冰川冻土》
CSCD
2024年第2期722-730,共9页
Journal of Glaciology and Geocryology
基金
冻土工程国家重点实验室自主研究课题(SKLFSE-ZY-19)
国家重点研发计划项目(2022YFF1302600)
中国铁路青藏集团有限公司科技研究开发计划项目(QZ2022-Z01)资助。
关键词
重力热管
管内温度监测
倾角
充液率
传热性能
two-phase closed thermosyphon
monitoring inside tube
inclination angle
filling rate
heat transfer performance
