相变微胶囊悬浮液喷淋换热特性实验研究

根据相变微胶囊储存和释放潜热的特殊性质，分别使用相变微胶囊悬浮液（MPCMS）和纯水作为喷淋介质，搭建了一个小型喷淋塔装置，其中相变微胶囊的芯材为正二十二烷(C₂₂H₄₆)。实验设定了五个喷淋温度(35、40、44、47、51℃)、三个空气流量(0.011、0.018、0.025 m³/s)和两种直径(SMD=80、240 μm)的大、小液滴作为实验变量，探究了上述两种介质与空气之间的换热特性。实验结果表明：相变微胶囊的过冷会影响换热过程。常温常湿条件下，对于小液滴，当空气流量为0.018、0.025 m³/s时，喷淋温度为44、47℃的MPCMS比相同温度下的纯水更能促进换热；当空气流量为0.011 m³/s时，喷淋温度为44℃的MPCMS比相同温度下的纯水更能促进换热。对于大液滴，在三种空气流量下，喷淋温度为44℃的MPCMS比相同温度下的纯水作为喷淋介质时换热效果更好。

Experimental study on spray heat transfer characteristics of microencapsulated phase change material suspension

According to the special properties of microencapsulated phase change material to store and release latent heat, microencapsulated phase change material suspension (MPCMS) and pure water were used as spray media respectively to build a small spray tower device, in which the core material of microencapsulated phase change material is n-dodecane (C₂₂H₄₆). Five spray temperatures (35, 40, 44, 47, 51℃), three air flows (0.011, 0.018, 0.025 m³/s) and two diameters (SMD=80, 240 μm) were set as experimental variables. The heat transfer characteristics between the two media that described and air were investigated. The experimental results show that the supercooling of the phase change microcapsules will affect the heat transfer process. Under normal temperature and humidity, for small droplets, when the air flow rate is 0.018 and 0.025 m³/s, MPCMS at 44 and 47℃ can promote heat transfer better than pure water at the same temperature. When air flow rate is 0.011 m³/s, MPCMS at 44℃ can promote heat transfer better than pure water at the same temperature. For large droplets, MPCMS with spraying temperature of 44℃ has better heat transfer effect than pure water with spraying medium at the same temperature under three kinds of air flow.