Si粉对太阳能热发电用SiC基陶瓷储热材料热导率的影响  

Effect of Si on the Thermal Condutivity of SiC-based Ceramic Thermal Storage Materials for Solar Thermal Power Generation

作　　者：徐晓虹 宋佳[1,2] 吴建锋 周炀[1,2] 马思童 李美勤[1,2] XU Xiao-hong;SONG Jia;WU Jian-feng;ZHOU Yang;MA Si-tong;LI Mei-qin(Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory,Foshan 528200,China;State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]先进能源科学与技术广东省实验室佛山分中心(佛山仙湖实验室),佛山528200 [2]武汉理工大学硅酸盐建筑材料国家重点实验室,武汉430070

出　　处：《武汉理工大学学报》2022年第11期6-12,共7页Journal of Wuhan University of Technology

基　　金：先进能源科学与技术广东省实验室佛山分中心(佛山仙湖实验室)开放基金(XHD2020-001).

摘　　要：太阳能热发电储热陶瓷材料既要有良好的机械性能、较高的热稳定性,同时又必须具有较高的热导率,以便实现快速的储热和放热,提高储热效率。传统无压烧结法制备的SiC陶瓷材料虽成本较低,但致密度低及热导率远低于高温高压制备的致密化SiC陶瓷。引入结合相或烧结助剂可提高传统无压烧结SiC陶瓷热导率。本研究在SiC基储热陶瓷中引入Si粉,采用XRD、SEM及FE-SEM等研究了Si粉添加量对SiC基复相储热陶瓷结构与性能的影响规律。结果表明,SiC基储热陶瓷中添加Si粉,可改善储热陶瓷结构与性能,当Si粉的添加量达到质量分数4%时(E4),样品的结构与性能较佳,抗折强度为182.56 MPa,体积密度达到2.54g/cm^(3),热导率为13.44 W/(m·K),储热密度高达1020.56kJ/kg。SiC颗粒表面生成SiC晶须属VSL机制,通过SiC表面晶须的桥联作用,提高了SiC基复合储热陶瓷材料的热导率。The thermal storage materials for thermal power generation should have good mechanical properties,high thermal stability and high thermal conductivity,so as to achieve rapid tehrmal storage and thermal release and improve the thermal storage efficiency.SiC materials prepared by traditional pressureless sintering method have low cost,but it is difficult to achieve densification,which leads to its thermal conductivity being far lower than that of densified SiC prepared at high temperature and high pressure.Based on the traditional pressureless sintering,it is feasible to improve its thermal conductivity by introducing bonding phase or sintering additives.The influence of Si content on the microstructure and properties of SiC based thermal storage ceramics was investigated by SEM,XRD,FE-SEM and so on.Sample E4(4%Si)sintered at 1460℃has the best comprehensive performance,and its bending strength and bulk density are 182.56MPa and 2.54g/cm^(3),the thermal conductivity and thermal storage density are 13.44 W/(m·K)and 1020.56kJ/kg.SiC whiskers were formed on the surface of SiC particles by VSL mechanism.The in-situ formed whiskers can form a network structure to connect SiC particles,reduce the scattering effect of phonons,significantly improve the thermal conductivity,and emhance the thermal storage performance.

关 键 词：太阳能热发电 SiC基陶瓷储热材料 热导率 SIC晶须 

分 类 号：TQ174.7[化学工程—陶瓷工业]