石蜡与石蜡/膨胀石墨复合材料充/放热性能研究  

STUDY ON THE CHARGING/DISCHARGING CHARACTERISTICS OF PARAFFIN AND PARAFFIN/EXPANDED GRAPHITE COMPOSITE MATERIAL

作　　者：夏莉[1] 张鹏[1] 周圆[1] 王如竹[1] 

机构地区：[1]上海交通大学制冷与低温研究所,上海200240

出　　处：《太阳能学报》2010年第5期610-614,共5页Acta Energiae Solaris Sinica

基　　金：上海市教育委员会科研创新项目(No.08ZZ99)

摘　　要：利用相变材料的充/放热实验台测试石蜡及石蜡/膨胀石墨(质量比分别为93/7及90/10)复合相变材料的充/放热性能。实验表明纯石蜡在充热过程中自然对流是其主要的换热方式,而放热过程中导热是主要的换热方式。在充/放热过程中,石蜡的充/放热效率都较低。而对于石蜡/膨胀石墨复合相变材料,其导热能力较石蜡有很大提高,但由于添加了膨胀石墨而削弱了对流换热,其换热方式是以导热为主。因此,添加膨胀石墨对充热速率提高不多,而对放热速率有大幅度提高。石蜡/膨胀石墨(93/7)复合材料充热过程所用时间为石蜡的62%,放热过程的时间为石蜡的43%。石蜡/膨胀石墨(90/10)复合材料充热过程所用时间为石蜡的52%,放热过程的时间为石蜡的35%。The charging/discharging characteristics of paraffin and paraffin/expanded graphite composite materials have been investigated experimentally. Composite paraffin/expanded graphite phase change materials containing 10% and 7% mass fraction of expanded graphite were prepared. During the charging process of paraffin, natural convection played a crucial role in the heat transfer; during the discharging process of paraffin, conduction was the main means of heat trans- fer. The experimental results, during beth charging and discharging process, indicated the heat-transfer rate of paraffin is very small because of its low thermal conductivity. The expanded graphite with high thermal conductivity is added in paraffin and the thermal conductivity of the composite phase change material is remarkably enhanced, whereas natural conv- ection is reduced because the paraffin is absorbed in the holes of the expanded graphite. As for the paraffin/expanded graphite composite material containing 7 % of expanded graphite, the time of charging and discharging process decreased respectively by 38% and 57%, as compared with that of paraffin. As for the paraffin/expanded graphite composite mate-rial containing 10% of expanded graphite, the time of charging and discharging process decreased respectively by 48% and 65 %, as compared with that of paraffin.

关 键 词：相变材料 石蜡 膨胀石墨 充/放热性能 

分 类 号：TK513.5[动力工程及工程热物理—热能工程]