摘要
以高孔隙率泡沫金属材料作为骨架制备而成的新型复合相变储能材料的导热系数将大大高于相变材料本身的导热系数,在储能过程中具有更好的传热效果。给出了较通用的高孔隙率泡沫金属材料等效导热系数的估算公式,并利用准稳态方法建立了复合相变材料在凝固过程的数值模型,对其凝固过程的传热特性进行了理论分析。以铝—石蜡和铜—石蜡复合材料作为研究对象。分析表明,采用复合储能材料可以使得其传热性能得到很大提高,但是也会使复合材料的储能能力有所降低。提出了一种平衡储能能力和传热性能的方法,当泡沫金属处于平衡孔隙率时,在传热性能得到极大提高的同时也使得其储能能力降低不多。同时,分析得到了外部换热环境对储能能力、传热性能以及平衡孔隙率的影响,即较大的对流换热时,若要取得适当的储能能力和传热性能,则需要较小的孔隙率。
The thermal conductivity of a new type of phase change material storage with high porosity metal foams is higher than the thermal conductivity of the phase change material itself, and the composite performs much better on heat transfer. The general formulation of effective thermal conductivity of the composite was used to calculate the solidification process of the composite using the method of thermal resistance and quasi-static. With the example of paraffin-aluminum and paiaffin-cuprmn we can obtain the knowledge that higher bulk porosity results in higher ability of energy storage and lower ability of heat transfer. At the point at which dimensionless thermal power and capacity are equal the composite can be considered suitable for both energy storage and heat transfer. Finally the vesult showed that external thermal environment limits the chosen of the ability of energy storage and heat transfer.
出处
《太阳能学报》
EI
CAS
CSCD
北大核心
2007年第7期739-744,共6页
Acta Energiae Solaris Sinica
关键词
泡沫金属
多孔介质
相变
准稳态法
热阻
metal foams
porous material
phase change
methods of quasi-static
thermal resistance
