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由于在相变过程中相变材料微胶囊能够吸收/释放大量的潜热,使得潜热型功能热流体具有较大的表观比热.然而近年来有学者研究发现,由于潜热型功能热流体热导率较低,其对流换热能力受到了削弱,甚至在某些条件下要低于水的换热性能.本文针对潜热型功能热流体的热导率较低的问题,研制了纳米材料增强的潜热型功能热流体,并且进行了管内强制对流换热实验研究,结果表明:添加0.5%TiO2纳米颗粒使得潜热型功能热流体的对流换热性能得到了明显改善,且相变材料微胶囊的浓度越高,纳米材料对换热性能的改善幅度越大,可使平均壁面温度降低达18.9%.
Due to the phase change material microcapsules can absorb / release a large amount of latent heat, the latent heat functional fluid has a large apparent specific heat. However, some scholars have found in recent years that due to the latent heat function thermal fluid thermal conductivity The convectional heat exchange capacity is weakened and even lower than that of water in some conditions.In this paper, in view of the low thermal conductivity of latent heat functional fluid, the nanomaterial reinforced The results show that the addition of 0.5% TiO2 nanoparticles makes the convective heat transfer performance of the latent heat functional fluid significantly improved, and the concentration of phase change material microcapsules The higher the improvement of the heat transfer performance of nano-materials, the average wall temperature can be reduced by 18.9%.