【作者】 黄金；

【导师】 张仁元；

【作者基本信息】 广东工业大学 ， 材料学， 2005， 博士

【摘要】 热能存储技术可以解决热能供给和需求失配的矛盾,因而是提高能源利用率和保护环境的有效手段。利用相变材料的相变潜热来存储热能的技术,具有储能密度大、蓄放热过程近似等温、过程易控制等优点,倍受研究者的关注。 本文率先采用自发熔融浸渗工艺实现了熔融无机盐和陶瓷预制体的浸渗复合,并成功地制备出Na₂SO₄/SiO₂新型复合相变储能材料。该材料既兼备了现有无机盐相变蓄热材料和固相显热蓄热材料两者的长处,又克服了两者的不足。在储能过程中,该材料可与相容性流体直接接触换热,大大提高了换热效率。 本文从热力学、静力学和动力学的角度出发,分析了自发熔融浸渗全过程,确立了自发浸渗过程应符合的热力学和静力学条件,并建立了熔融无机盐Na₂SO₄渗入SiO₂多孔陶瓷预制体的动力学模型,理论上确定了浸渗过程的各个影响因素并详细分析了它们之间的相互关系,形成了较为完整的无机盐/陶瓷基复合相变储能材料自发熔融浸渗理论体系。在理论研究的基础上,通过实验,以石英粉为骨料,淀粉为造孔剂,配以一定量其它添加剂,采用单面加压成型,1200～1300℃烧结,成功地制备出显气孔率在40～50%,孔径大小介于5～40/μm,平均孔径为26～30/μm之间,骨料颗粒之间粘结较好,形成了较为理想的三维空间网络孔洞结构的多孔陶瓷预制体,该预制体完全可以用于进行后续的自发熔融浸渗研究。 在分析了硫酸钠和石英之间具有很好的高温化学相容性和浸润性的基础上,进行浸渗合成实验,测试了各试样的浸渗率和相对密度,分析了预制体制备工艺和浸渗合成工艺对复合储能材料的浸渗率和相对密度的影响,获得最佳工艺参数,确定浸渗温度在900～1000℃,浸渗时间在1小时左右,浸渗方式采用浸液浸渗,并最终成功地制备出了浸渗率（Na₂SO₄的百分含量）在42.3%～53.4%,相对密度高达92%～95%的复合相变储能材料。 利用金相显微镜、扫描电镜、X射线衍射、X射线能谱仪等手段,分析了复合储能材料的物相组成、晶型变化及其显微组织结构。研究结果表明最终制备出的复合相变储能材料在常温下的主要物相为α—石英和芒硝Na₂SO₄—T,与制更多还原

【Abstract】 Heat energy storage technique can solve the mismatch of energy supply and demand. It is an effective measure to improve energy utilization efficiency and protect environment for lack of energy resource. Research workers pay much attention to the technique that makes full use of phase change materials’（PCMs） latent heat to store heat energy for its high heat storage density and its isothermal process in melting and freezing.In this paper, a new type salt/ceramic composite energy storage material（CESM） is fabricated successfully by applying an innovating technology firstly which is molten Na₂S)₄ infiltrating porous ceramics performs spontaneously. This material which composed of sensible ceramic heat storage materials and molten salt latent heat storage materials integrates their advantages and overcomes their disadvantages. In the process of energy storage, this material can exchange heat by contacting directly with compatible fluid, so the efficiency of exchanging heat is improved greatly.The conditions of thermodynamics and statics and the kinetics model of molten salt infiltrating porous ceramics performs are established. Influence factors of infiltrating process are ascertained theoretically and their correlation is analyzed. A whole system info of molten salt infiltrating porous performs spontaneously is formed. In experimentation, powder of quartz is used for main raw material and starch is used for pore forming material. Through half-dry press molding, 1200-1300 °C sintering, a three-dimensional network structural porous ceramics performs is fabricated successfully that porosity is 40-50%, pore size is 5-40 μ m and average pore size is 26-30 μ m. It is feasible completely that these performs are used for later infiltrating research.High temperature chemical compatibility and wetting between molten Na₂SO₄ and quartz are analyzed. Through infiltrating experiment, a new NaSO₄/SiO₂ CESM is fabricated successfully that infiltration percentage is 42.3-53.4% and relative更多还原