储热型吸附式空气取水器吸附剂与储热材料的选择

摘要

本文针对太阳能储热型吸附式空气取水器吸附剂和储热材料的选择,分别研究了以膨胀硫化石墨(ENG-TSA)和以活性炭纤维(ACF)毡为基质的复合吸附剂的导热系数和吸附性能,硬脂酸/膨胀硫化石墨(ENG-TSA-SA)复合相变储热材料的导热系数与DSC测试.结果表明:ENG-TSA-LiCl复合吸附剂的导热系数最大可达5.67 W/(m·K),吸水量最大可达1.54 g/g.真空浸渍法获得的ACF-LiCl复合吸附剂的吸水量比大气浸渍法高.ASLi40固化吸附剂的吸水量为1.59 g/g,适用于大批量生产.ENG-TSA-SA的径向导热系数为22.2 W/(m·K),相变温度区间为65.9～77.1℃,适用于太阳能等低品位热能.储热器的添加明显延缓了解吸温度降低的趋势.%Alternatives to the sorbents and heat storage materials used for a heat storage sorption air intake device driven by solar energy were examined in this study.These included thermal conductivity and the sorption kinetic performance of composite sorbents using expand ed natural graphite treated with sulfuric acid (ENG-TSA) and activated carbon fiber (ACF) felt as porous host matrixes,and thermal conductivity,and differential scanning calorimetry (DSC) test for the composite phase-change thermal energy storage materials,i.e.,stearic acid (SA)/ENG-TSA.The results revealed that the best thermal conductivity of the composite sorbent ENG-TSA-LiCl was 5.67 W/(m·K),and the largest water uptake was 1.54 g/g.The sorption performance of the composite sorbent ACF-LiCl using a vacuum impregnation method was better than that when using the atmospheric impregnation method.The water uptake of the consolidated sorbent of ASLi40 was 1.59 g/g,which can be applied to mass production.ENG-TSA-SA was suitable for solar energy and other low-grade heat energy recovery applications,with a high radial thermal conductivity (22.2 W/(m·K)) and appropriate internal phase transition temperature (65.9-77.1 ℃).The addition of a heat reservoir significantly slowed down the decrease to the desorption temperature.