PHASE-CHANGE MATERIALS FOR ENERGY-STORAGE NUCLEATION TO PREVENT SUPERCOOLING
PHASE-CHANGE MATERIALS FOR ENERGY-STORAGE NUCLEATION TO PREVENT SUPERCOOLING
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DOI：
10.1016/0927-0248(92)90116-7
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发表时间：
1992-07-01
影响因子：
6.9
通讯作者：
LANE, GA
中科院分区：
文献类型：
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作者：
LANE, GA
相变材料（PCMs）是有用的存储热作为核聚变的潜热。这种储存在加热和冷却建筑物、废热回收、非高峰电力利用、热泵系统和许多其他应用中具有潜力。已被证明在储热应用中有用的pcm是六水氯化钙，CaCl2。6H2O，六水氯化镁，MgCl2。6H2O和六水硝酸镁，Mg(NO3)2。6水。许多盐水合物pcm，包括上面列出的，缺点是在提取储存热量的过程中，材料在冷冻前过冷。这降低了材料的效用，如果太严重可以完全阻止热回收。许多因素决定了一种特殊的添加剂是否会促进成核，例如晶体结构、溶解度和水合物稳定性。从晶体学数据表中选择晶体结构与PCM结构吻合良好的候选同形和同型成核添加剂。外延形成核材料的选择主要依靠直觉，其促进成核的晶格结构特征不明显。两种方法都发现了有效的成核剂。根据实验室测试结果，有前途的材料被开发成基于CaCl2的配方。6H2O MgCl2。6H2O Mg(NO3)2。6H2O Mg(NO3)2。6 h2o-mgcl2。6H2O共晶，Mg(NO3)2。6H2O-NH4NO3共晶盐水合物PCMs。随后，试图将晶体结构和水合物稳定性与成核效率联系起来，并推测活性成核结构。
Phase change materials (PCMs) are useful for storing heat as the latent heat of fusion. Such storage has Potential in heating and cooling buildings, waste heat recovery, off-peak power utilization, heat pump systems, and many other applications.Among the PCMs that have proven useful in heat storage applications are calcium chloride hexahydrate, CaCl2 . 6H2O, magnesium chloride hexahydrate, MgCl2 . 6H2O, and magnesium nitrate hexahydrate, Mg(NO3)2 . 6H2O.Many salt hydrate PCMs, including those listed above, have the disadvantage that during extraction of stored heat the material supercools before freezing. This reduces the utility of the material, and if too severe can completely prevent heat recovery.Many factors determine whether a particular additive will promote nucleation, for example, crystal structure, solubility, and hydrate stability. Candidate isomorphous and isotypic nucleating additives, with crystal structures that fit well with the PCM structure, were selected from tables of crystallographic data.Epitaxial nucleators, with less obvious lattice structure features that promote nucleation, were selected mostly by intuition. Effective nucleators were discovered by both methods.Based on laboratory test results, promising materials were developed into formulations based on CaCl2 . 6H2O, MgCl2 . 6H2O, Mg(NO3)2 . 6H2O, Mg(NO3)2 . 6H2O-MgCl2 . 6H2O eutectic, and Mg(NO3)2 . 6H2O-NH4NO3 eutectic salt hydrate PCMs. Subsequently, attempts were made to correlate crystal structure and hydrate stability with nucleating efficacy, and to speculate about active nucleating structures.