Zigzag PCHE内熔盐/S-CO_(2)流动与换热特性研究

Heat Transfer Performance of zigzag PCHE With Molten Salt and Supercritical CO_(2)in CSP System

印刷电路热交换器(PCHE)是一种高效紧凑型换热器,是高温光热发电技术的理想换热部件。本文构建了Zigzag PCHE数理模型,研究了熔盐/超临界CO_(2)(S-CO_(2))在流道内流动和换热特性。采用SST k-ω湍流模型,分析了流道结构和流体流速对熔盐与S-CO_(2)对流换热特性的影响。结果表明,在流道结构的作用下,流动和换热特性呈周期性变化。传热阻力主要在气体侧,总换热系数随着S-CO_(2)入口流量的增大而提高,压降也随之增大。并基于Zigzag型结构进行了通道优化,压降降低了约50%,提高了换热器性能。

The printed circuit heat exchanger(PCHE)is a highly efficient and compact heat exchanger,and serves as an ideal heat transfer component in high-temperature solar thermal power generation technology.In this study,a mathematical model of Zigzag PCHE is constructed to investigate the flow and heat transfer characteristics of molten salt and supercritical CO_(2)(S-CO_(2)).The SST k-ωturbulence model is utilized to study convective heat transfer characteristics between molten salt and S-CO_(2).Results show that temperature and heat transfer coefficient periodically vary with periodical structure.The heat transfer resistance mainly occurs on the S-CO_(2)side and the overall heat transfer coefficient increases with the inlet flow rate of S-CO_(2).Additionally,Sin structure is performed to improve the heat transfer performance based on the Zigzag PCHE.