Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
University of Udine, Via delle Scienze 206, 33100, Udine, Italy.
Waste Manag. 2018 Mar;73:322-331. doi: 10.1016/j.wasman.2017.06.031. Epub 2017 Jun 28.
This study reports the thermal analysis of a novel thermal energy storage based on high temperature phase change material (PCM) used to improve efficiency in waste-to-energy plants. Current waste-to-energy plants efficiency is limited by the steam generation cycle which is carried out with boilers composed by water-walls (i.e. radiant evaporators), evaporators, economizers and superheaters. Although being well established, this technology is subjected to limitations related with high temperature corrosion and fluctuation in steam production due to the non-homogenous composition of solid waste; this leads to increased maintenance costs and limited plants availability and electrical efficiency. The proposed solution in this paper consists of replacing the typical refractory brick installed in the combustion chamber with a PCM-based refractory brick capable of storing a variable heat flux and to release it on demand as a steady heat flux. By means of this technology it is possible to mitigate steam production fluctuation, to increase temperature of superheated steam over current corrosion limits (450°C) without using coated superheaters and to increase the electrical efficiency beyond 34%. In the current paper a detailed thermo-mechanical analysis has been carried out in order to compare the performance of the PCM-based refractory brick against the traditional alumina refractory bricks. The PCM considered in this paper is aluminium (and its alloys) whereas its container consists of high density ceramics (such as AlO, AlN and SiN); the different coefficient of linear thermal expansion for the different materials requires a detailed thermo-mechanical analysis to be carried out to ascertain the feasibility of the proposed technology.
本研究报告了一种新型基于高温相变材料（PCM）的热能存储的热分析，该材料用于提高废物能源工厂的效率。目前的废物能源工厂的效率受到蒸汽发生循环的限制，该循环是通过由水冷壁（即辐射蒸发器）、蒸发器、省煤器和过热器组成的锅炉来进行的。尽管这种技术已经得到了很好的应用，但它受到了与高温腐蚀和蒸汽产量波动相关的限制，这是由于固体废物的非均匀组成所致；这导致了维护成本的增加和工厂可用性和电力效率的限制。本文提出的解决方案是用基于 PCM 的耐火砖代替典型的安装在燃烧室中的耐火砖，这种耐火砖能够存储可变的热通量，并根据需要释放稳定的热通量。通过这种技术，可以减轻蒸汽产量波动，在不使用涂层过热器的情况下将过热蒸汽温度提高到当前腐蚀极限（450°C）以上，并将电力效率提高到 34%以上。在目前的论文中，进行了详细的热机械分析，以比较基于 PCM 的耐火砖与传统氧化铝耐火砖的性能。本文中考虑的 PCM 是铝（及其合金），而其容器由高密度陶瓷（如 AlO、AlN 和 SiN）组成；不同材料的线性热膨胀系数不同，需要进行详细的热机械分析，以确定所提出技术的可行性。
