大孔径规则多孔介质强化石蜡熔化的实验研究

Experimental Study on Enhancing Paraffin Melting Rate with the Large-Aperture Regular Porous Media

强化相变材料熔化是提高与之相关的储热装置效率的有效途径,区别于既往常见的泡沫金属强化相变材料熔化,本文以黄铜为材料设计加工了一种大孔径规则多孔介质,并将其与石蜡和PC圆管组成实验段.以只填充石蜡的实验段作为对照,通过可视化实验和典型位置处瞬时温度的测量考察了该类型多孔介质强化石蜡熔化的作用效果和机理.结果表明:填充大孔径规则多孔介质实验段内的石蜡在熔化过程中无明显的糊状区.此外,与只填充石蜡的实验段相比,填充大孔径规则多孔介质的实验段内固-液界面向上移动的高度较高且温升速率显著较快.再者,该类型多孔介质可显著强化距离加热壁面较远的测点C的自然对流传热,从而使其温度在500 min后高于距离加热壁面最近的测点C的温度.

It is an effective way of improving related thermal storage equipment to enhance phase change materials melting rate.In the aspect of pore structure,it is different between the common foam metal and the large-aperture regular porous media developed by us,which is made of brass and is part of the test section together with paraffin and PC circular tube.Compared with the test section with only paraffin,the effect and mechanism of the large-aperture regular porous media on paraffin melting rate enhancement was investigated through visualization experiment and transient temperature measurement of typical locations.The results show that,there is no mushy zone during paraffin melting process for the test section with the large-aperture regular porous media.Additionally,the moving height of solid-liquid interface is larger and temperature rise is faster for paraffin in the test section with the large-aperture regular porous media compared with the test section with only paraffin.Also,the large-aperture regular porous media could significantly enhance natural convection at the location of measuring point Cwhere it is farther from the heating surface,and the temperature at this location was higher than that of the nearest measuring point Cafter 500 minutes.