匹配高温氟盐堆的SCO_(2)系统冷端变工况运行特性研究

Study on Off-design Operating Characteristics of Cold-end System for SCO_(2)Cycle Matching Fluoride-salt-cooled High-temperature Small Reactor

高温氟盐堆与超临界二氧化碳(SCO_(2))布雷顿循环耦合的小型发电系统具有高效、紧凑和高固有安全性而被认为在小型核动力/核发电领域具有良好发展前景。本文针对高温氟盐堆与SCO_(2)布雷顿循环的耦合系统开展了系统优化设计与变工况运行特性研究。基于高温氟盐堆热端特征和冷端环境条件设计和对比了多种循环构型下的系统性能,发现对于2种反应堆循环回路系统,采用再压缩循环在循环热效率和紧凑性综合方面具有优势,在此基础上研究了冷端系统SCO_(2)布雷顿循环系统变工况运行特性,发现当主压缩入口温度改变时,采用定压比运行模式不仅循环效率高,且对冷端环境温度变化适应性范围也大。因此当环境温度变化时,布雷顿循环推荐采用定压比运行模式。

The small power generation system of supercritical carbon dioxide(SCO_(2))Brayton cycle coupled with fluoride-salt-cooled high-temperature small reactor is considered to have a good development prospect in the field of small nuclear power/nuclear power generation because of its high efficiency,compactness and high inherent safety.In this paper,the optimization design and offdesign operation characteristics of cold-side for supercritical carbon dioxide Brayton cycle are studied.Based on the Fluoride-salt-cooled high-temperature small reactor characteristics and environment conditions,various SCO_(2)cycle configurations are compared,and it is found that the main compressor interstage cooling and reheat can improve thermal efficiency,but increase of limited,and extra heat exchangers are added.Then,the off-design operation characteristics of SCO_(2)cycle cold side system is investigated.The operation mode with constant pressure ratio not only has high cycle efficiency,but also has a wide adaptability range to the temperature change of the environment.Therefore,the constant pressure ratio operation mode is recommended for SCO_(2)cycle when the ambient temperature changes.