过冷水合盐相变材料跨季节储存太阳能研究进展

摘要

Seasonal solar energy storage can be used to alleviate the disadvantages of the solar radiation instability and the mismatch contradiction between the solar energy supply and demands of the building load, and improve the efficiency of solar energy utilization. Based on the comparison among different types of seasonal heat storage methods,the paper mainly reviewed the seasonal thermal storage technology using supercooled salt hydrate phase change materials(PCMs)and corresponding research progress. Firstly,The principle of supercooled thermal storage and key problems in storage system were analyzed,including the selection of salt hydrates,the stable supercooling implementation of salt hydrates,the activation methods of crystallization to release energy,system matching design and performance,phase separation and corrosion of salt hydrates. It was indicated that the calcium chloride hexahydrate,the sodium phosphate dibasic dodecahydrate,the sodium acetate trihydrate and the sodium thiosulfate pentahydrate were suitable PCMs because of appropriate phase transition temperature and the large heat storage density. In addition,corresponding with other key problems of the storage system,the effecting factors and the solution strategies were also analyzed,which could provide theoretical basis and guidance for system design and practical application of seasonal heat storage using supercooled salt hydrates. Finally,the outlook for further research was presented.%跨季节储存太阳能可以缓解太阳辐射不稳定以及与建筑负荷供需不匹配的矛盾,提高太阳能利用效率.本文在比较各类跨季节蓄热方式基础上,着重阐述了过冷水合盐相变材料跨季节蓄热技术及研究进展.分析研究了过冷水合盐跨季节蓄热原理和系统及目前研究的焦点问题,包括水合盐相变材料的选择、稳定过冷的实现、触发释能方法、系统匹配设计和性能、相分离和腐蚀性.结果指出六水氯化钙、十二水磷酸氢二钠、三水合乙酸钠和五水硫代硫酸钠由于相变温度适宜、储热密度较大等优点,是跨季节蓄热材料的研究重点.其次针对系统存在的其他焦点问题,逐一分析其影响因素并总结了目前解决策略,为水合盐过冷跨季节蓄热系统的设计和实际应用提供理论依据和指导,最后指出了进一步研究的方向.