Latent heat storage units are considered as an effective solution for the mismatch problem between energy consumption and energy supply when utilizing solar energy. However, the low thermal conductivity of the current phase change materials (PCMs) is regarded as their main drawback. The present study used dispersing nanoparticles in PCM and installing longitudinal fins on the inner tube simultaneously to enhance the melting rate of PCM in a horizontal shell-and-tube heat exchanger. Different compositions of stearic acid (SA) and titanium dioxide TiO₂-NPs were employed as nano-encapsulated PCMs as well. The results demonstrated that installing fins have a significant effect on the melting rate of PCM and can improve the melting rate by 68%. Although adding 0.39 wt% TiO₂-NPs to PCM enhanced its thermal conductivity of SA by 7 and 15% in liquid and solid phases, respectively, its effect on improving the melting rate of PCM was less than 4%, which is related to the weakening of the natural convection flows because of the increased viscosity.

潜热存储单元被认为是解决利用太阳能时能源消耗和能源供应不匹配问题的有效解决方案。然而，当前相变材料（PCM）的低导热率被认为是它们的主要缺点。本研究使用了将纳米颗粒分散在PCM中并在内部管上同时安装纵向散热片的方法，以提高卧式管壳式换热器中PCM的熔化速率。硬脂酸（SA）和二氧化钛TiO ₂ -NPs的不同组成也被用作纳米封装的PCM。结果表明，安装散热片对PCM的熔化率有显着影响，并且可以将熔化率提高68％。尽管添加0.39重量％的TiO ₂-NPs对PCM在液相和固相中SA的热导率分别提高了7％和15％，其对PCM熔融速率的影响小于4％，这与自然对流的减弱有关，因为粘度增加。