Abstract:

Increasing the specific heat capacity of the molten salt material can effectively enhance its heat storage capacity, reduce the area of the heat storage system and heat loss, and thus reduce the heat storage cost. It is a research hotspot in the field of medium and high temperature energy storage in recent years. In this paper, the research progress on the enhancement of specific heat capacity of molten salt heat transfer and storage materials in recent years is reviewed from the aspects of necessity, method and mechanism of strengthening molten salt heat storage materials. The methods of adding soluble additives and doped heterogeneous nanoparticles to form nanofluids to enhance the specific heat capacity of molten salt and their current problems are elaborated in detail. The preparation methods of molten salt nanofluids, heterogeneous nanoparticle systems, strengthening effects and the mechanism are emphatically discussed. In addition, the current shortcomings of using nanofluids to strengthen the specific heat capacity of molten salt heat storage materials are pointed out as insufficient research system, poor suspension stability and imperfect specific heat capacity strengthening mechanism. And the future development direction of molten salt nanofluid are prospected, including the development of multi-system molten salt nanofluids, the multi-aspect revealing of specific heat capacity strengthening mechanism and the multi-method measurement of molten salt nanofluid physical properties.

Key words: heat storage, molten salt, specific heat capacity, nanoparticles, agglomeration

摘要：

强化熔盐材料比热容可以有效增强熔盐材料的蓄热能力，减小蓄热系统面积及热损失，进而降低蓄热成本，是近年来中高温储能领域的研究热点。本文主要从熔盐储热材料比热容强化的必要性、强化方法和强化机理等方面综述了近年来熔盐传热蓄热材料比热容强化的研究进展。具体阐述了添加可溶性添加剂和掺杂异质纳米颗粒形成纳米流体两种强化熔盐比热容的方法及目前存在的问题，重点探讨了熔盐纳米流体的制备方法、异质纳米颗粒体系、强化效果及比热容强化机理等问题。此外，指出了当前利用纳米流体强化熔盐储热材料比热容方面存在的不足：研究体系单一、悬浮稳定性差和比热容强化机理不完善等，并对熔盐纳米流体的未来发展方向，即多体系熔盐纳米流体的开发，多手段比热容强化机理的揭示和多方法熔盐纳米流体物性的测量进行了展望。

关键词: 储热, 熔盐, 比热容, 纳米粒子, 团聚