泡沫金属铜布置方式对石蜡相变放热性能的影响

Effect of Layout of Copper Foam on Heat Release Performance of Paraffin Wax

为改善石蜡作为相变材料导热差、蓄热时间长的问题,本文将泡沫金属铜放入填充石蜡的圆柱体蓄热箱内,设计泡沫金属铜垂直蓄热箱横截面半径方向布置、沿横截面半径方向布置、沿横截面水平方向布置3种方案,研究不同布置方案对石蜡基复合相变材料的传热影响以及石蜡/泡沫金属铜复合材料的放热特性。实验结果表明:泡沫金属铜的加入缩短了石蜡凝固时间,方案一和方案三中凝固时间均缩短5 min,方案二中凝固时间缩短4 min,同时改善了石蜡不同位置的温度均匀性,内圈测点中复合材料区的温度均匀性比纯石蜡区增大80%,外圈测点中方案一的温度波动是方案二和方案三的33%和50%;方案一比方案二的有效放热量多2.2%,放热效率增加5.05%;方案一比方案三的有效放热量多1.1%,放热效率增加2.01%,而且保持70%以上的传热效率,与冷流体换热效果最佳,方案一为最优布置方案。

In order to improve the poor thermal conductivity and long-term heat storage of paraffin as a phase change material(PCM),this study placed copper foam into a cylindrical heat storage device filled with paraffin.Three cases were designed,namely,the vertical distribution of copper foam in the radius direction of the cross section,distribution along the radius direction of the cross section,and distribution along the horizontal direction of the cross section.The influence of different layout cases on the heat transfer of paraffin-based PCM and the heat release characteristics of paraffin/metal copper foam composites were studied.The experimental results show that the addition of copper foamed metal shortens the solidification time of paraffin.The solidification time of case 1 and case 3 is shortened by five minutes,and the solidification time of case 2 was shortened by four minutes.Simultaneously,the temperature uniformity of the paraffin at different positions was improved.The temperature fluctuation of case 1 in the outer ring measurement point is 33%and 50%of those of cases 2 and 3,respectively.The effective heat release of Case 1 is 2.2%higher than that of Case 2,and the heat release efficiency increases by 5.05%.The effective heat release of Case 1 is 1.1%higher than that of Case 3,and the heat release efficiency increases by 2.01%.The heat transfer efficiency of case 1 is maintained at more than 70%,and the heat transfer effect with cold fluid is the best,which is the optimal layout case.