熔盐堆超临界二氧化碳布雷顿循环系统与热力学分析

熔盐堆（MSR）能实现在线填料和后处理，出口温度较高，应配备一种与之出口温度相匹配的创新型循环方式，且可达到较高的循环效率。本文基于中国科学院上海应用物理研究所设计的小型模块化熔盐堆（smTMSR-400）设计超临界二氧化碳（SCO₂）布雷顿循环系统，使用控制变量法分析了分流比、压缩机/透平效率、主压缩机出口温度、低温换热器换热温差/阻力对SCO₂布雷顿循环系统的影响。分析结果表明:①存在最佳分流比使低温换热器两侧温差相等；②相较于压缩机效率，等幅度的透平效率提升可使系统循环效率和?效率更高；③主压缩机出口压力增大为系统带来正面影响，但循环效率/?效率与其斜率都逐渐降低；④换热器换热温差和流动阻力都为系统循环带来了可量化的负担: 换热温差每增加10 K，循环效率降低1.85%，?效率降低2.70%；流动阻力每增加1 MPa，循环效率降低6.58%，?效率降低10.22%。最后根据分析结果和系统?流变化设计了5种物理参考方案。 

MSR Supercritical Carbon Dioxide Brayton Cycle System and Thermodynamic Analysis

Molten salt reactor (MSR) can realize on-line packing and post-processing, and the outlet temperature is higher, so it shall be equipped with an innovative cycle mode that matches its outlet temperature, and can achieve higher cycle efficiency. In this paper, a supercritical carbon dioxide (SCO₂) Brayton cycle system is designed based on the small modular molten salt reactor (smTMSR-400) designed by Shanghai Institute of Applied Physics, Chinese Academy of Sciences. The effects of split ratio, compressor/turbine efficiency, outlet temperature of main compressor and heat exchange temperature difference/resistance of low temperature heat exchanger on SCO₂ Brayton cycle system are analyzed by using the control variable method. The analysis results show that: ①there is an optimal split ratio to make the temperature difference between the two sides of the low temperature heat exchanger equal; ②compared with the compressor efficiency, the equal-amplitude turbine efficiency improvement can make the system cycle efficiency and exergy efficiency higher; ③ the increase in the outlet pressure of the main compressor has a positive impact on the system, but the cycle efficiency/exergy efficiency and its slope gradually decrease; ④the heat exchange temperature difference and flow resistance of the heat exchanger bring quantifiable burden to the system cycle: for every 10 K increase in the heat exchange temperature difference, the cycle efficiency decreases by 1.85% and exergy efficiency decreases by 2.70%; When the flow resistance increases by 1 MPa, the cycle efficiency decreases by 6.58% and exergy efficiency decreases by 10.22%. At last ,this paper designs 5 physical reference schemes based on the analysis results and system exergy changes.