翅片管式蓄热器固液相变传热特性的实验研究

An Experimental Study of Solid-liquid Phase Change Heat Transfer Characteristics in the Finned Tube Thermal Energy Storage

本文设计搭建了固液相变蓄热实验测试系统,研究翅片管式蓄热器内部的固液相变传热性能,获得了固液相变过程中相变材料区域以及翅片径向,轴向方向上的温度变化,重点讨论相变材料区域的温度变化及翅片对固液相变过程的影响规律。研究结果表明,相变材料区域熔化过程可分成初始升温期,相变平缓期,加速升温期,温度饱和期四个阶段,翅片区域的温度变化则经历了快速升温、温度平缓、缓慢升温三个阶段。在翅片温度变化平缓期,其周围的相变材料处于固液相变期间,当翅片温度开始缓慢升温时,其附近的相变材料区域已处于液体状态。在固液相变发生前,翅片上轴向温度分布较均匀,在整个相变过程中,系统轴向方向相变区域的温度分布较为均匀。

A solid-liquid phase change thermal energy storage system was designed and established to investigate the solid-liquid phase change heat transfer characteristics of the f＇mned tube thermal energy storage system. The temperature variation features in the PCM domain, the radial and axial direction of fins were obtained. Particular attentions were paid on the temperature change regulations of PCM （Phase Change Material） and the influence of fins on phase change process. The results indicate that the melting process of PCM can be divided into four stages： initial temperature rise, steady phase change process, accelerated temperature increase and temperature saturation. Meanwhile, the temperature change of fms has three stages, which are quick temperature increase, gentle temperature variation and slow temperature increase. When the temperature of fins gently changes, the surrounding PCM has been in the duration of the solid-liquid phase transition process. Subsequently, the fin temperature begins to rise slowly with the surrounding PCM being a liquid state. What＇s more, the temperature distribution is relatively uniform in the axial direction of fins before the solid-liquid phase transition occurs. While during the whole phase transition process, the axial temperature distribution in phase change domain becomes gradually uniform.