Applied Thermal Engineering ( IF 6.1 ) Pub Date : 2020-03-23 , DOI: 10.1016/j.applthermaleng.2020.115233 Jianjuan Yuan , Chendong Wang , Ji Zhang , Jihong Ling , Zhihua Zhou , Feng Gao
With the development of building energy saving technology, low-temperature two-phase closed thermosyphon (TPCT) will be widely used in building energy supply and storage. However, the non-condensable gas (NCG) can affect the performance of TPCT. In this paper, experiment, theoretical heat transfer model and CFD simulation model have been established to comprehensive analyze the operation performance of the TPCT with NCG (NTPCT). The research contents include the variation of TPCT wall temperature, heat transfer efficiency (), thermal resistance () and NCG phase distribution. Experimental results showed that the temperature difference between the evaporator and condenser sections of the NTPCT was greater than that of the TPCT in the steady state, resulting in being higher than , and the difference was widening with the decrease of input temperature (), leading to serious adverse impact on heat transfer. When was higher than 60℃, the difference with different mass of NCG (=0.0418%∼0.0746%) was small, but when was low, the difference became larger, and even when =27℃, the =44.02% for =0.0418%, and =0.04% for =0.0746%, i.e., the heat pipe failed to work. In addition, with the decrease of inclination angle, NCG diffused downward and occupied more and more length of the condenser section, resulting in worse and worse heat transfer performance.
中文翻译:
不可冷凝气体对两相闭式热虹吸管热特性的影响
随着建筑节能技术的发展,低温两相闭式热虹吸管(TPCT)将被广泛应用于建筑能源的供应和存储。但是,不可凝气体(NCG)会影响TPCT的性能。本文建立了实验,理论传热模型和CFD仿真模型,以全面分析带NCG(NTPCT)的TPCT的运行性能。研究内容包括TPCT壁温的变化,传热效率(), 热阻 ()和NCG相位分布。实验结果表明,在稳态下,NTPCT的蒸发器和冷凝器之间的温差大于TPCT的, 高于 ,随着输入温度的降低,差异不断扩大(),对传热造成严重不利影响。什么时候 高于60℃, 不同质量的NCG的差异(= 0.0418%〜0.0746%)很小,但是当 低,差异变大,甚至 = 27℃, = 44.02% = 0.0418%,并且 = 0.04% = 0.0746%,即热管无法工作。另外,随着倾斜角的减小,NCG向下扩散并占据越来越多的冷凝器部分的长度,导致传热性能越来越差。