相变储能技术的传热强化方法综述

Review on Heat Transfer Enhancement Methods of Latent Heat Storage Technology

相变储热技术能够解决热能传递过程中的时空不连续问题,可有效减少热能的损耗,加速中国碳中和目标实现进程。但受限于相变材料的低导热特性,实际应用中的相变储热系统均需配置相应的传热强化装置,使系统复杂性和投资成本大幅增加。本文对相变储热技术的传热强化方法进行了简要分类,即单一传热强化技术、组合传热强化技术、多级传热强化技术以及液态PCM流动强化技术,并对后三者的不足进行阐述和说明。同时,基于相应结论,归纳总结了热源与热汇的三种相对几何关系,即扩张式、平行式和收缩式,可有效指导相变储热器结构总体设计。最后,对相变储热技术的未来应用进行了展望,应基于热力学和系统论等知识,从系统层面完成相变储热器的设计,实现热力学性能和经济性的最优。

Latent heat storage(LHS)technology can solve the time-space non-continuity in the transfer process of thermal energy,which can effectively reduce heat loss and accelerate the realization of China′s carbon neutrality goal.However,the LHS system in practical applications needs to be equipped with heat transfer enhancement devices,considering the low thermal conductivity of phase change materials(PCMs),which significantly increases the system complexity and capital cost.In this review,heat transfer enhancement methods,namely single heat transfer enhancement technology,combined heat transfer enhancement technology,multi-stage heat transfer enhancement technology,and liquid PCM flow enhancement technology,are briefly classified.The corresponding shortcomings of the last three technologies are described and explained.Based on the obtained conclusions,three relative geometric relations between the heat source and heat sink are summarized,namely the expansion type,parallel type,and contraction type,which can effectively guide the overall design of the latent heat storage units.Finally,the future application prospectives of latent heat storage technology are discussed.It is necessary to design latent heat storage from the system level based on knowledge of thermodynamics and system theory to achieve optimal thermodynamic performance and economic efficiency.