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采用实验方法对圆柱空腔内相变材料(石蜡)的熔化过程进行研究,石蜡通过放置在中央位置的加热棒进行定功率加热。通过改变加热功率、水浴温度以及外壁的边界条件,记录石蜡相变过程中不同位置的温度变化情况,对比不同条件对熔化进程的影响。相变界面和熔化份额采用温度的三次插值和位置加权处理获得。熔化起始阶段,受到纯导热的影响,靠近加热棒的石蜡开始熔化,随之的自然对流的产生和加剧加快上部区域固体石蜡的熔化,最终在整个液体区域形成明显的温度分层。实验结果表明,提高斯蒂芬数Ste或者降低过冷度Sc对熔化进程有显著的促进作用。
The melting process of the phase change material (paraffin) in the cylindrical cavity was studied experimentally, and the paraffin wax was heated at a constant power using a heating rod placed in a central location. By changing the heating power, the temperature of the water bath and the boundary conditions of the outer wall, the changes of the temperature at different positions during paraffin phase transformation were recorded, and the influence of different conditions on the melting process was compared. The phase change interface and melting fraction are obtained by cubic interpolation of temperature and position weighting. At the initial stage of melting, due to the effect of pure thermal conductivity, the paraffin wax near the heating rod begins to melt, followed by the natural convection and acceleration of solid paraffin melting in the upper region, finally forming a distinct temperature stratification in the entire liquid region. The experimental results show that increasing the Stefan number Ste or lowering the supercooling degree Sc has a significant effect on the melting process.