【作者】 郭英利；

【导师】 李新国；

【作者基本信息】 天津大学 ， 制冷与低温工程， 2008， 硕士

【摘要】 能源、环境与节能是全球面临的紧迫和重要工作,要加强新能源与可再生能源的利用,减少常规能源的消耗。实施能量短期或长期蓄存以达到能量补充和再利用目的。相变蓄能技术具有蓄能密度高、易匹配、易控制的众多优点,相变蓄能的研究与应用得到广泛关注。本文将对石蜡相变材料的相变传热过程进行理论与实验研究。对相变传热数学模型和求解方法的研究。介绍对比一般的相变传热模型,研究几种求解方法的主要思想,本文研究圆管外相变材料的相变传热简化数学模型。圆管外石蜡相变蓄热熔化规律的实验研究。建立一个小型圆管外石蜡蓄热实验系统,研究石蜡在不同位置的相变规律,分析自然对流对熔化的影响,得出熔化时间与熔化厚度的优化值;研究不同加热水温与不同水流量对石蜡熔化规律的影响;研究单热源与双热源对石蜡熔化影响的不同。圆管外石蜡相变释热凝固规律的实验研究。分析石蜡在圆管外不同位置的凝固规律,自然对流对释热过程的影响;研究不同冷源温度影响凝固过程的差异性,得出自然对流出现的临界启动温差;研究不同的流量对相变造成的不同影响;以及分析比较单冷源与双冷源造成凝固过程的差别。更多还原

【Abstract】 Energy, environment and energy saving have already been the world’s urgent and important work. New and renewable energy should be used to reduce conventional energy’s consumption. The short-term or long-term energy stored technique would be suitable method to supply and reuse energy. Due to the merits of high-density energy storage, easy to match and easy to control, the research and application of Phase Change Thermal Energy Storage (PCTES) technique has drawn more attention. This paper will research the heat transfer process of paraffin phase change in theoretical and experimental aspects.The mathematical models and methods of phase change heat transfer were studied. And a simplified heat transfer mathematical model of pipe outside phase change was researched in this paper.Experimental study on paraffin melting process’s law of phase change outside pipe was carried out in different locations and the impact of natural convection to melting process was analysed. The optimal melting time and paraffin thickness have been gained. Different impacts caused by different water temperature and flow to paraffin melting were researched. Contrast on different impacts to paraffin melting process between one heat source and two heat sources.In heat release experiment, the paraffin solidification law of phase change outside pipe was carried out in different locations and the impact of natural convection to solidification was analysed. By contrasting on the impacts of different water temperature, a critical temperature different activating natural convection has been gained. Comparing with one cold source, two cold sources would cause different effects to solidification.更多还原