【摘要】 作为一种新型的蓄热材料,纳米相变胶囊能够解决热量供求时间、空间和强度上的不匹配,在余热回收、太阳能热利用、电子器件热管理等多个领域具有广阔的应用前景。从样品制备、物性表征以及传热强化3个方面,对纳米相变胶囊最新的研究成果进行了总结。介绍了常见的纳米相变胶囊制备方法及对形貌、尺寸的影响,比较了各种方法的优劣。物性表征的结果显示,胶囊化的方式可以有效防止相变材料发生泄露,获得更好的热稳定性。纳米相变胶囊显著提升了相变材料的导热系数、降低了相变材料的过冷度,同时也没有造成相变乳液的黏度出现大幅度提高。此外,实验和数值模拟的结果都表明纳米相变胶囊能够有效提升工质的传热性能。更多还原

【Abstract】 Nano-encapsulated phase change materials(NEPCM) have the potential to address the intermittent and less predictable nature of renewable energy resources. Other applications of the NEPCM include waste heat utilization, energy-saving buildings and thermal management of electronics. This paper introduces the latest research in NECPM preparation, characterization and heat transfer enhancement. The influence of preparation method on particle size and morphology of NEPCM are discussed. The characterization results show nanoencapsulation is able to effectively prevent the leakage of PCM and achieve an excellent thermal stability of PCM emulsions. In addition, the use of NEPCM could also effectively alleviate the rapid increase in the viscosity of PCM emulsions, and improve the thermal conductivity while reduce the subcooling degree of PCMs. Furthermore, both numerical and experimental studies have shown the benefit of NEPCM for heat transfer enhancement.更多还原