固-固相变储热及其材料制备和性能优化技术(Ⅰ)  

Fabrication and Performance Optimization Technology of Materials for Solid-Solid Phase Change Thermal Energy Storage(Ⅰ)

作　　者：李天天[1,3] 李宝让 刘文洁[1] 赵鹏翔[2] 杜小泽 LI Tiantian;LI Baorang;LIU Wenjie;ZHAO Pengxiang;DU Xiaoze(North China Electric Power University Key Laboratory of Power Station Energy Transfer Conversion and System,Ministry of Education,Beijing 102206,China;State Grid Integrated Energy Service Group Co.,Ltd,Beijing 100052,China)

机构地区：[1]华北电力大学,电站能量传递转化与系统教育部重点实验室,北京102206 [2]国网综合能源服务集团有限公司,北京100052 [3]华北电力大学能源动力与机械工程学院

出　　处：《材料导报》2022年第5期165-179,共15页Materials Reports

基　　金：国家电网公司《多能互补分布式能源系统的关键技术研究》项目。

摘　　要：相变储热技术作为当前储热研究领域中的重点,在能源利用效率的提高方面效果显著。作为高效储热技术之一,固-固相变储热主要通过固体相变实现热量的吸收和释放。相比于固-液相变储热,固-固相变储热相变过程中体积变化小,同时无明显相分离、泄露等现象,在节能、环保和新能源等诸多领域中具有巨大的发展潜力。有机固-固相变储热材料主要包括高分子聚合物、多元醇以及层状钙钛矿,其中聚合物类主要由"软相"大分子借助化学键连接"硬相"聚合物骨架形成。"软相"作为相变过程的主体,升温至转变温度发生固-液转变;而"硬相"骨架限制其宏观流动,起到维持固体形态的作用。多元醇在低温下呈现层状晶体结构,层间分子通过氢键相连接,进行固相转变时部分氢键断裂,分子转向面心立方晶体结构。层状钙钛矿则是由有机层的长链烷烃以及无机层的金属配位四面体[MX_(4)^(2-)]交替组合而成的夹层状晶体结构,其固-固相变机理与高聚物相似,即有机层的长烷基链进行有序-无序转变,而无机层结构保持不变。现阶段在有机固-固相变储热材料的制备技术方面,聚合物类材料主要通过接枝共聚、嵌段共聚等方法,以聚乙二醇为相变介质借助化学键结合到聚合物骨架上而形成;多元醇适用于中高温工作条件下,其相变温度和相变焓与所含氢键数相关,通过多元复合配比可调整其热物性能;层状钙钛矿的热物性取决于其组成烷基链的长度,可选择制备多元体系以拓宽相变温度范围。近年来,为满足实际应用中对高储热功率的要求,除了致力于开发新型相变储热材料外,研究人员对相变材料的导热强化技术也在不断改进中。本文基于固-固相变的机理,针对当前国内外固-固相变储热技术的研究,分别从相变行为的特征、材料制备、性能优化技术和应用等方面对固-固相变储Thermal energy storage technology depending upon phase change is the hot spot in the field of heat storage research,which has a significanteffect on improving energy utilization efficiency.As one of the high-efficiency thermal energy storage technologies,solid-solid phase change thermal energy storage mainly realizes the absorption and release of heat through solid phase transformation process.Compared with the solid-liquid phase change thermal energy storage,the volume change of solid-solid phase change is smaller,and there is no obvious phase separation and leakage phenomenon.It has attractive development potential in many fields such as energy conservation,environmental protection and new energy.The organic materials in solid-solid phase change thermal energy storage field mainly include polymer,polyhydric alcohols and layered perovskite.Among them,polymeric phase change materials are mainly formed by the‘soft phase’macromolecules connected with the‘hard phase’polymer skeleton by means of chemical bonds.The‘soft phase’is the main part of the phase transformation process,and the solid-liquid transition occurs when the temperature rises to the transition temperature.The‘hard phase’skeleton restricts its macro flow and plays an important role in maintaining the solid morphology.At low temperature,polyhydric alcohols present a layered crystal structure.The interlayer molecules are connected by hydrogen bonds,and part of the hydrogen bonds break during the solid phase transition,and the molecules change to face centered cubic crystal structure.Layered perovskite is an intercalated crystal structure composed of long chain alkanes in organic layer and metal coordination tetrahedron[MX_(4)^(2-)]in inorganic layer.Its solid-solid phase transition mechanism is similar to that of polymer,that is,the long alkyl chain of organic layer undergoes order-disorder transformation,while the inorganic layer structure remains unchanged.At present,in the preparation technology of organic solid-solid phase change ther

关 键 词：固-固相变 储热材料 相变机制 

分 类 号：TK02[动力工程及工程热物理]