超临界二氧化碳与液态铅铋合金耦合换热模型与换热特性研究  

Study on coupling heat transfer model and characteristics of supercritical carbon dioxide and liquid lead-bismuth eutectic

作　　者：崔大伟 宋磊 林继铭 CUI Dawei;SONG Lei;LIN Jiming(CGN Research Institute Co.,Ltd.,Shenzhen 518000,China)

机构地区：[1]中广核研究院有限公司,广东深圳518000

出　　处：《热力发电》2022年第6期59-67,共9页Thermal Power Generation

基　　金：国家自然科学基金项目(U20B200381)。

摘　　要：铅冷快堆和超临界二氧化碳(S-CO_(2))布雷顿循环因其高的热效率、紧凑式设计被认为是最具前景的发电系统之一。液态铅铋合金(Pb/Bi)和S-CO_(2)在中间换热器耦合换热,然而2种流体的湍流输运特性与耦合传热行为相较于常规流体差异巨大,常规湍流模型无法准确预测其耦合换热性能。为获得两者间耦合传热的准确预测模型、掌握耦合传热规律,首先针对管内液态Pb/Bi和S-CO_(2)的湍流普朗特数(Prt)模型的适用性进行了比较分析,发现冷、热侧分别选择Tang、Cheng和Tak提出的Prt模型可获得准确结果;对两者的耦合换热模型进行了深入分析与校验,模拟结果与实验数据吻合良好;全面探讨了雷诺数、工质温度对2种特殊流体耦合传热能力的影响,发现套管式换热器热阻主要存在于S-CO_(2)侧,提升S-CO_(2)侧参数可以迅速提高传热性能,且当S-CO_(2)工质温度处于拟临界区时换热器的换热能力将大幅增强。Lead cooled fast reactor and supercritical carbon dioxide(S-CO_(2)) Brayton cycle are considered to be one of the most promising power generation systems because of their high thermal efficiency and compact design.Heat transfer occurs between lead bismuth alloy(Pb/Bi) and S-CO_(2) in the intermediate heat exchanger.However,the turbulent transport characteristics and coupling heat transfer behavior of Pb/Bi and S-CO_(2) are different from that of conventional fluids.The conventional turbulence prediction models can not accurately predict the coupling heat transfer performance.In order to obtain an accurate prediction model and reveal the rules of the heat transfer between Pb/Bi and S-CO_(2),the applicability of the exsiting turbulent Prandtl models of Pb/Bi and S-CO_(2) is compared and analyzed at first.It finds that Tang’s Prandtl model on the S-CO_(2) side and Cheng & Tak’s Prandtl model on the Pb/Bi side can obtain accurate results.Then,the coupling heat transfer models for Pb/Bi and S-CO_(2) are further analyzed and verified,the simulation results are in good agreement with the experimental data.The effects of Reynolds number and inlet temperature on the coupling heat transfer performance between S-CO_(2) and Pb/Bi are fully discussed.It finds that the heat resistance of the casing heat exchanger mainly exists on the S-CO_(2) side,increasing the flow rate of S-CO_(2) can quickly improve the heat transfer performance,and the heat transfer capacity of the heat exchanger is greatly enhanced when the main temperature of S-CO_(2) is in the quasi critical zone.

关 键 词：铅铋合金 超临界二氧化碳 中间换热器 耦合换热 

分 类 号：TL334[核科学技术—核技术及应用]