贮热材料四卤合金属酸(Ⅱ)二烷基铵二元亚固相相图的研究

The storage and utilizing of thermal energy by Phase Change Materials is one of the most important technology to improve the energy efficiency and protect the environment. This project is aimed at gaining high enthalpy of the thermotropic solid-solid phase transitions materials and the suitable phase transition temperature in the bis(n-alkylammonium) tetrachlorometallate. Subsolidus binary phase diagram were established by differential thermal analysis (DTA), X-ray diffraction (XRD) and IR in 293K-423 K temperature range, according to the second law of thermodynamics and phase equilibrium theory. It is used to ensure the phase equilibrium process of the materials and determine basic chemical thermodynamics data, discusses structure characteristics of phase change materials and the relationship of between materials heat storage and heat transfer by the phase diagram. The experimental data were further optimized and evaluated by the CALPHAD technology. It is to predict the thermodynamic properties and the phase equilibrium of the expected material for thermal storage. Selecting the suitable heat storage materials from the phase diagram, thermodynamic performance which include the phase-change temperatures, phase change enthalpy, specific heat capacity, heat storage density of were determined. It is experimental determination and theoretical simulation that provide a helpful theory for this project to select the high efficiency, low cost and suitability of the solid-solid phase change heat storage materials.

利用相变贮热材料实现能量的贮存和利用，是提高能源利用效率和保护环境的重要技术之一。本项目为了获得相变焓值高且相变温度适宜的四卤合金属酸(Ⅱ)二烷基铵固-固相变贮热材料，依据热力学第二定律和相平衡理论，通过差热分析、X射线，及变温红外等实验技术，构筑材料在293K-423K温度范围内的二元亚固相实验相图。通过相图确定材料相平衡的过程，测定各相的基础化工热力学数据，探讨相变材料的结构特征与材料贮热、传热之间的关系规律。并利用 CALPHAD技术，对已有的实验结果数据进行理论优化和评估，预测相图中待选贮热材料的热力学性质及相平衡关系。从相图中筛选出适宜的多元相变贮热材料，确定相变温度，相变焓，比热容和能量密度等贮热性能。本项目实验测定相图和理论模拟互为补充，为选择高效、低成本、适宜的固-固相变贮热材料提供理论依据.

利用相变贮热材料实现能量的贮存和利用，是提高能源利用效率和保护环境的重要技术之一。本项目为了获得相变焓值高且相变温度适宜的四卤合金属酸(Ⅱ)二烷基铵(1-CnH2n+1NH3)2MX4(M=Cu、Mn、Zn… …，X=Cl、Br)固-固相变贮热材料，依据热力学第二定律和相平衡理论，通过差热分析、X 射线，及变温红外等实验技术，构筑材料在293K-423K温度范围内的二元亚固相实验相图。在实验相图中确定了中间的化合物的存在，并确定了两个不变的共析点，与同类体系的其他相图相比 , 在此相图的左右边界存在端际固溶体( α和β ) 和中间区域存在非化学计量相( γ ) 。通过相图确定材料相平衡的过程，测定各相的基础化工热力学数据，探讨相变材料的结构特征与材料贮热、传热之间的关系规律。从相图中筛选出适宜的多元相变贮热材料，确定相变温度，相变焓，比热容和能量密度等贮热性能。本项目实验测定相图为选择高效、低成本、适宜的固-固相变贮热材料提供理论依据.