关键词: 相变材料, 储热技术, 传热强化, 储热器, 潜热流体

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