磁场影响的熔盐射流冲击传热实验研究

Experimental Study on Jet Impingement Heat Transfer With Molten Salt Under Influence of Magnetic Field

该文建立射流冲击传热实验装置,以永磁铁构建定磁场,进行外磁场作用下熔盐射流冲击传热的实验研究,得到对流换热系数径向分布及努谢尔特数驻点关联式。实验结果表明,磁场作用对于熔盐射流冲击过程具有一定的强化传热效果,使得熔盐努谢尔特数增大。特别是在驻点区,驻点努谢尔特数随着磁场强度的增加而增大;在雷诺数Re=6400和磁场强度B=2800Gs条件下,熔盐驻点努谢尔特数Nu0达到最大值,与未有磁处理的情况相比,提高了约5.48%;在壁面射流区,传热强化效果逐渐减弱。结果表明,磁场处理对于熔盐射流冲击传热效果具有比较好的促进作用。

In this paper, an experimental setup for jet impingement heat transfer was established. The permanent magnets were used to produce a constant external magnetic field for experimental study on jet impingement heat transfer with molten salt. Both the radial distribution of convective heat transfer coefficient and correlation of stagnation Nusselt number were obtained. The results showed that the heat transfer of molten salt could be enhanced by the function of magnetic field, resulting in increasing of Nusselt number of molten salt. Especially, in the stagnation region, stagnation Nusselt number increased with increasing of the intensity of magnetic field obviously. Under the conditions of Reynolds number Re=6400 and intensity of magnetic field B=2800 Gs, stagnation Nusselt number of molten salt reached a maximum value about 5.48% higher than without magnetic field. In the region of wall jet, the effect of heat transfer enhancement gradually decreased. It was shown that the magnetic treatment may promote distinctly heat transfer in jet impingement of molten salt.