Experimental study on forced convection heat transfer of helium gas through a minichannel
Experimental study on forced convection heat transfer of helium gas through a minichannel
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氦气微通道强制对流换热实验研究
DOI：
10.1016/j.ijheatmasstransfer.2021.121117
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发表时间：
2021
影响因子：
5.2
通讯作者：
Makoto SHIBAHARA
中科院分区：
文献类型：
--
作者：
Feng XU;Qiusheng LIU;Makoto SHIBAHARA
为了提高聚变堆的热效率和安全性，了解聚变包层中氦气冷却的传热过程是至关重要的。本文以氦气为工质，对水平微通道内湍流换热特性进行了实验研究。内径为1.8mm的圆形铂管通过直流电加热并通过氦气冷却。随着产热速率的e折叠时间的延长，热输入呈指数增加。所获得的实验数据进行了比较与经典的相关适用于传统的通道上的预测。阐明了各种实验参数对传热系数的影响。根据计算结果，与常规通道相比，微型通道的传热强化得到了证实。传热系数随流速的增加而增加，随内表面温度与气体本体温度之比的增加而减小。根据大量的实验数据，导出了小通道内氦气湍流流动的经验关联式，其偏差为±10%。
For the development of thermal efficiency and security of fusion reactors, it is vital to know the heat transfer process for helium gas cooling in the fusion blanket. In this paper, an experimental study was performed on the heat transfer characteristics for turbulent flow in a horizontal minichannel employing helium gas as the working fluid. A circular platinum tube with an inner diameter of 1.8 mm was heated by direct current and cooled by helium gas. The heat input was exponentially increased with a relatively long e-folding time of the heat generation rate. The obtained experimental data were compared with the predictions on classical correlations applied to conventional channels. The influence of various experimental parameters on the heat transfer coefficient was clarified. Based on the results, heat transfer enhancement was confirmed in the minichannel compared with the conventional channel. The heat transfer coefficient increased with increasing flow velocity and decreased as the ratio of inner surface temperature to gas bulk temperature increased. An empirical correlation for turbulent flow of helium gas in a minichannel with a deviation of ±10% was derived from a large quantity of experimental data.