【作者】 沈学忠；

【导师】 张仁元；

【作者基本信息】 广东工业大学 ， 材料学， 2007， 硕士

【摘要】 受到上世纪七十年代能源危机的影响，相变储热(LTES)的基础理论和应用技术研究在发达国家迅速崛起并得到不断发展。由于相变储能技术可以解决能量供求在时间和空间上不匹配的矛盾，因而是提高能源利用率和保护环境的有效手段。相变储能是利用相变材料(Phase Change Materials)的相变潜热来存储热能的技术，它具有储能密度大，蓄放热过程近似等温，过程易控制等优点，因而是热能储存的主要方式。因为相变储能技术的核心是相变材料，因此研究相变材料的成分、组织、结构和性能是相变储能技术的关键和基础。理想的相变材料应该具有大的相变潜热，不同工作条件下的合适相变温度，良好的储热性能和反复相变后性能的稳定性。铝硅合金的共晶温度一般认为是577℃(±1℃)，当其用作相变储能材料时，它的相变潜热为500 kJ／kg左右，具有储能密度大，所储热能品位高，热效率高，储热热系数大等特点，且价格适中，在中高温储能领域具有很大发展前景。抗高温氧化性能好是中高温储能材料的必备条件。氧化实验在箱式电阻炉中进行，空气为氧化介质，经过长达600小时，温度高达600℃的高温氧化后，铝硅合金每Cm~2的氧化增重仅为3.05mg，试样的增重稳定且缓慢。材料的热稳定性试验采用加速试验法，在自制的热循环试验炉上进行1800次的热循环，在不同的循环次数时取出相变材料以测试其熔点和潜热。实验结果显示，其熔点增高了2.4℃，潜热减低了23.4KJ／Kg。铝硅合金在相变过程中有液相的产生，具有一定的流动性，因此必须有容器盛装，且容器材料相对铝硅合金来说又必须是惰性的，不与铝硅合金生成低熔点的合金，容器材料必须密封，以防止泄露环境，造成对人员的伤害。本实验采取对容器进行热浸镀渗铝。研究了热浸镀渗铝的工艺，以及铝硅熔液对镀铝件的腐蚀性。实验表明，镀铝件具有很好的防铝硅熔液腐蚀的性能。通过本实验的研究，能够为铝硅合金用于相变储能提供必要的实验数据和理论支持。更多还原

【Abstract】 Because the 1980s energy crisis, the basic theory and application of technology of phase change thermal storage had been brought forward brought and continually developed in the developed country. Phase change thermal storage technique can solve the conflict between time and space, therefore, it is an important technique to improve its utilization efficiency and protect environment. Heat energy storage technique is a technique which Phase Change Materials (PCMs) storage energy. It has these virtues, such as: high thermal storage density, isothermal process in melting and freezing and so on. So it’s an important way of energy storage. Obviously, PCM is the key of energy storage technique, thus, studying element composition, structure and heat storage property are hinges and bases of heat energy storage technique. The ideal PCM should have high latent heat, appropriate temperature accord with work conditions, better heat storage property and property stability after repeating melting and freezing.The melting temperatures of Al-Si alloy is 577℃(±1℃) , and the latent heats of Al-Si alloy is about 500 kJ/kg, Ai-Si alloy has these characteristics: high latent heat ,High-grade heat of storages, high thermal efficiency, big heat storage coefficient and moderate prices. In the field of middle-high temperature energy storage Al-Si alloy has great prospects for development.One necessarily property of middle and high temperature PCMs was excellent performance of high temperature resistance oxidation. The oxidation behavior of eutectic Al-Si alloy were studied in air in box electric furnace. After 600 hours, Al-Si alloy added weight 3.05mg per square centimeter at 600℃, and the weight of sample increase steadily and slowly.Accelerated thrmal cycle tests have been conducted to study the changes in melting temperatures (T_m) and the latent heats of fusion (ΔH_m) of eutectic Al-Si alloy as PCMs after repeated numbers of melt/freeze cycles in home-made thermal cycling furnace. Experimental results show that its melting point increased 2.4℃, the latent heats reduced 23.4KJ/Kg. There might appear liquid phase in phase change of metal PCM and it has some flow property, so it must be loaded in the container, container must be inert and do not react with Al-Si alloy to product low-melting-point alloy, it must be airproofed. All of these measures avoid liquid leak, otherwise, that would cause people hurt and environment pollution.The experimental study of Al-Si alloy rovide necessary experiment data and theory support for its application in the field of phase change energy storage.更多还原