This work investigates an optimal model of the heat recovery from a double elliptical latent heat storage system using wavy inner tubes and nano-enhanced phase change material (PCM). A discharging rate and time, as well as the PCM thermal distribution in a three-dimensional simulation, are evaluated considering various alignments for both inner and outer ellipse pipes. The use of two inner tubes in two different cases considering straight and wavy tubes is also examined, followed by influences of various concentrations and types of nanoparticles. The inlet temperature and Reynolds number of heat transfer fluid (HTF) are also examined. ANSYS-FLUENT software is used to perform the numerical simulation. RT 35 and Silicon Carbide (SiC) are employed as the PCM and nanomaterials, respectively. Water is also considered as the HTF with the Reynolds number of 900. Different values of 20 and 40 mm are proposed for the horizontal and vertical radii of the outer tube to examine the different orientations of the elliptical tube considering the inner radius ranged from 4.95 to 14 mm. The findings show that the vertical alignment of the inner tube compound in the centre of the horizontal position of the outer tube presents higher efficiency during the solidification process. Using double pipes in both straight and wavy configurations increases the surface area, which enhances the heat transfer rate, accelerating the solidification rate by 1.26 and 1.1, respectively. The PCM compound with SiC nanoparticles with 2% and 4% concentrations accelerates the discharging rate by 2.8 and 4.8 times, respectively, compared with the single straight inner pipe case. Furthermore, it is found that by decreasing the temperature of the heat transfer fluid from 285 K to 280 K, the total solidification time reduces from 48 to 39 min.

这项工作研究了使用波浪形内管和纳米增强相变材料 (PCM) 的双椭圆潜热存储系统的热回收优化模型。考虑到内外椭圆管的各种对齐方式，评估了放电速率和时间，以及 3D 模拟中的 PCM 热分布。还检查了在考虑直管和波浪管的两种不同情况下使用两个内管，然后是各种浓度和类型的纳米粒子的影响。还检查了传热流体 (HTF) 的入口温度和雷诺数。ANSYS-FLUENT 软件用于进行数值模拟。RT 35 和碳化硅 (SiC) 分别用作 PCM 和纳米材料。水也被认为是雷诺数为 900 的 HTF。考虑到内半径范围为 4.95 到14 毫米。研究结果表明，内管化合物在外管水平位置中心的垂直排列在凝固过程中表现出更高的效率。在直管和波浪配置中使用双管增加了表面积，从而提高了传热速率，分别将凝固速率加快了 1.26 和 1.1。具有 2% 和 4% 浓度的 SiC 纳米颗粒的 PCM 化合物分别将放电速率加快了 2.8 倍和 4.8 倍，与单直内管情况相比。此外，发现通过将传热流体的温度从 285 K 降低到 280 K，总凝固时间从 48 分钟减少到 39 分钟。