Abstract:

Phase change material heat storage technology has the advantages of high heat storage density, stable phase change temperature, and easy process control. It has broad application prospects in the fields of solar thermal utilization, industrial waste heat recovery, building energy conservation, and electronic device thermal management. Under normal circumstances, the phase change material needs to complete the heat storage and release process in the application. The heat transfer enhancement of heat storage technology transfer characteristics directly determine the time of heat storage and release and the application mainly includes three aspects, one is the heat conduction enhancement of the phase change material, the second is the convection heat transfer enhancement of the latent heat functional thermal fluid,and the third is the heat transfer enhancement of the energy storage heat exchanger. Inorganic and organic phase change materials have low thermal conductivity, which can be combined with high thermal conductivity materials to improve their thermal conductivity. The phase change material is used to increase the specific heat capacity of the latent heat thermal fluid, thereby the heat capacity can be improved, and the heat transfer can be enhanced. High-efficiency heat storage devices such as plate type and spiral coil type are used to realize heat transfer enhancement in the process of heat storage and release. This article reviews the research progress of heat transfer enhancement in phase change heat storage technology at home and abroad, mainly introduces the heat conduction enhancement of phase change materials, such as expanded graphite and metal foam. The heat transfer enhancement of microencapsulation phase change material, latent heat emulsion, and the heat transfer enhancement of thermal storage heat exchanger such as shell and tube, plate and spiral coil heat exchanger. On the whole, the expanded graphite-based composite phase change material has high thermal conductivity, large heat storage density and good shaping characteristics, which has great application prospects. Latent functional thermal fluid has the advantages of large apparent specific heat capacity and small flow resistance, but it has disadvantages such as poor stability and large degree of subcooling. The plate heat storage has a large heat transfer area and high heat transfer power, and is suitable for use in a phase change material heat transfer system. However, due to different application backgrounds, the selection and guidance of different heat storage devices for different scenarios is worthy of further research.

Key words: phase change material, energy storage technology, heat transfer enhancement, heat exchanger, latent heat fluid

摘要：

相变储热技术具有储热密度大、相变温度稳定以及过程容易控制等优点，具有广泛应用前景。相变储热技术在应用中需完成热能的储存与释放过程，其传热特性直接决定应用效果。储热技术的传热强化主要包括三个方面：一是相变材料本身的导热强化；二是潜热型功能热流体的对流传热强化；三是储热器的传热强化。本文综述了国内外在相变储热技术的传热强化研究方面的进展，主要介绍了膨胀石墨、泡沫金属等复合相变材料的导热强化，相变微胶囊及相变微、纳米乳液潜热型功能热流体传热强化以及管壳式储热器、板式储热器、螺旋盘管储热器等储热器的传热强化。文章指出，膨胀石墨基复合相变材料具有高热导率、大储热密度以及良好的定型特性，且价格低廉，极具应用前景。纳米乳液功能热流体具有表观比热容大、流阻较小等优势，但存在稳定性较差、过冷度大等问题。板式储热器具有较大的传热面积、较高的传热功率，适宜应用于相变材料传热系统。但应用背景不同，针对不同场景提供不同储热器的选型及指导值得作进一步的研究。

关键词: 相变材料, 储热技术, 传热强化, 储热器, 潜热流体