内翅式太阳能球形胶囊传热特性研究

采用Fluent软件对球形胶囊蓄热单元进行了传热特性分析;并使用恒温水浴锅加热蓄热单元来模拟恒温加热环境,对球形胶囊内翅片的熔化过程进行实验验证。获得了球形胶囊内部监测点的温度时间曲线。将模拟结果和实验结果进行对比,得到较好的一致性,验证了胶囊内相变材料的熔化模型的准确性。根据模拟与实验的结果优化蓄热单元,以带有内翅片的球形胶囊蓄热单元为研究对象,将KNO3作为相变材料,对翅片同厚度(1.5 mm)、不同翅片长度(0 mm、58.5 mm、68.5 mm、73 mm)的蓄热单元建立四个模型。结果表明,胶囊内添加翅片增大传热效率,且随着翅片长度的增大,胶囊内温度分布均匀化;对球形胶囊内翅片传热分析具有指导意义。

Research on heat transfer characteristics of spherical capsual heat storage unit with internal fins

Conducting heat transfer analysis of the spherical encapsulated phase change materials(Epcms) by using Fluent software. It has been applyed thermostatic water bath heating system to imitating heating environment, and performed both melting and solidification experiments of commercial grade paraffin wax within glass spherical capsules, obtained the temperature time curve of the monitoring point of spherical capsule. The simulated results were comprehensive compared with the experimental results, and it was found in good agreement with the experimental results. It has been verified the accuracy of the melting and solidification model of the PCM material. According to the results of simulation and experiment, taked the spherical Epcms heat storage units with inner fins as the research object, used KNO3 as the PCM, and established four models of the same fin thickness(1.5 mm) and different fin length(0 mm, 58.5 mm, 68.5 mm, 73 mm). The results show that Epcm add the fins to increase heat transfer efficiency and tends to be stable with the increase of the fin length. It has a certain theoretical guiding significance to analysis of the heat transfer in spherical capsules.