【摘要】 为研究膨胀石墨对石蜡熔化和凝固性能的影响,对膨胀石墨石蜡复合相变蓄热材料的熔化和凝固过程进行数值分析,并与纯石蜡相变蓄热材料的熔化和凝固过程进行对比。且分析不同含量的膨胀石墨及不同壁面温度对石蜡熔化和凝固过程的影响,结果表明:石蜡中添加膨胀石墨能明显缩短石蜡的熔化和凝固时间,且熔化和凝固时间都随着膨胀石墨含量的增加而减少;在同种工况下,与纯石蜡对比,添加1%、2%、5%膨胀石墨的复合石蜡熔化时间分别减少2.14、2.81、9.74倍;凝固时间则分别减少0.77、1.05、3.76倍;壁面温度对复合石蜡的熔化过程影响显著,而对凝固过程影响程度不佳;其中在初始温度相同的条件下,与壁面温度为327 K的工况下5%EG复合石蜡全部熔化的时间对比,壁面温度为332 K及337 K的工况下5%EG复合石蜡全部熔化的时间分别缩短了0.83、1.58倍。更多还原

【Abstract】 To study the effect of expanded graphite on the melting and solidification properties of paraffin wax, the solidification and melting process of expanded graphite paraffin wax composite phase change heat storage material was numerically simulated and compared with that of pure paraffin wax phase change heat storage material. The effects of a different content of expanded graphite and a different wall temperature on the melting and solidification process of paraffin wax were analyzed. The results show that the addition of expanded graphite to paraffin wax can obviously shorten the solidification and melting time of the paraffin wax, and the melting and solidification time decreases with the increase of the expanded graphite content. Under the same working conditions, compared with pure paraffin, the melting times of composite paraffin with 1%, 2%, and 5% expanded graphite were reduced by 2.14, 2.81 and 9.74 times, respectively, and the solidification time was reduced by 0.77,1.05, and 3.76 times, respectively. The wall temperature has a significant effect on the melting process of composite paraffin but not on the solidification process. When the initial temperature is the same,compared with the melting time of 5% EG composite paraffin wax under the wall temperature of 327° K,when the wall temperature is 332° K and 337° K, the melting time of 5% EG composite paraffin wax is shortened by 0.83 and 1.58 times, respectively.更多还原