同轴型热虹吸系统轴向传热特性实验研究

Experimental Investigation on the Axial Heat Transfer of a Coaxial Thermosyphon

对一种用于冷中子源系统的自然循环进行了轴向传热特性研究,建立了以氟里昂为工质的同轴型热虹吸管传热实验系统。研究表明:同轴型热虹吸系统可强化轴向热传输能力,其传热工况有过冷沸腾流动振荡工况、稳定工况和烧干工况3类。在低功率区,过冷沸腾和携带机制造成启动过程的两相流振荡;进入稳定工况区后,系统具有自调适能力,能够维持恒定的循环质量流率;在高功率区,蒸发器烧干产生传热极限。本研究显示出同轴型热虹吸系统的动力特性与普通自然循环系统有明显区别,其循环机制与普通热虹吸系统有本质区别。

The axial heat transfer performance of a natural circulation, which could be used in the cold neutron source (CNS), was experimentally investigated. A two-phase closed thermosyphon system using Freon-113 as work fluid was established. Three kinds of possible flow modes were observed, namely, subcooled boiling oscillation under lower heating flux, stable flow and heat transfer region and dry-out mode under higher heating flux. The result shows that the CNS type coaxial thermosyphon has distinct dynamic performance obviously different from that of a natural circulation in the boiling water reactor (BWR) as well as that of conventional single tube thermosyphon.