摘要
低温热管换热器是天然气液化系统中的关键装置,液氮脉动热管作为其核心器件具有体积小、换热效率高等特性,可有效克服系统冻堵及设备紧凑等问题,然而开展相应实验难度较大,因此通过数值模拟方法研究其内部传热传质规律具有重要意义。首先,文章通过UDF(User-Defined Functions)编写自适应相变模型,研究了典型液氮脉动热管的传热传质特性。随后,在冷凝段优化设计了波纹结构,结合相态分布与轴线温度方差值,对比分析了充液率为50%情况三种液氮脉动热管传热传质特性,结2果表明5 mm波纹结构热管两侧方差值为51.49 K与99.22 K2,工质循环速率较快且轴线温度分布均匀。最后,研究了充液率分别为30%、50%与70%情况下5 mm波纹结构的脉动热管的传热性能。结合相态、温度及轴线温度分布分析得出充液率过高或过低均会导致热管内部产生液塞,充液率较高时,轴线温度均匀分布,热管充液率为70%时,综合性能最佳。
Low temperature heat pipe heat exchanger is the key device in natural gas liquefaction system.As its core device,liquid nitrogen pulsating heat pipe has the characteristics of small size and high heat exchange efficiency,which can effectively overcome the problems of system freezing and compact equipment.However,it is difficult to carry out corresponding experiments,so it is of great significance to study the internal heat and mass transfer through numerical simulation.Firstly,the heat and mass transfer characteristics of a typical liquid nitrogen pulsating heat pipe are studied by using an adaptive phase transition model compiled by UDF.Then,the corrugated structure is optimized in the condenser,and the heat and mass transfer characteristics of the three types of liquid nitrogen pulsating heat pipes are compared with the phase distribution and the axis temperature variance when the liquid filling ratio is 50%.The results show that the variances on both sides of the 5 mm corrugated heat pipes are 51.49 K2 and 99.22 K2,and the working fluid circulation rate is fast and the axis temperature distribution is uniform.Finally,the heat transfer performance of the pulsating heat pipe with 5 mm corrugated structure is studied with liquid filling ratio of 30%,50%and 70%,respectively.According to the analysis of phase,temperature and axial temperature distribution,too high or too low liquid filling ratio will lead to liquid plug inside the heat pipe.When the liquid filling ratio is high,the axial temperature distribution is uniform,and the comprehensive performance of the heat pipe is the best when the liquid filling ratio is 70%.
作者
沈涛
王强
郭超
代云中
Shen Tao;Wang Qiang;Guo Chao;Dai Yunzhong(College of Engineering,Yibin Vocational and Technical College,Yibin,Sichuan 644000,China)
出处
《化工设备与管道》
CAS
北大核心
2024年第4期64-71,共8页
Process Equipment & Piping
基金
四川省教育厅重点实验室开放课题(SCITLAB-1013)
宜宾职业技术学院科研平台:数字西部机械职业教育研究中心(ybny21kypt-03)。
关键词
液氮
脉动热管
数值模拟
传热传质
liquid nitrogen
pulsating heat pipe
numerical simulation
heat and mass transfer
