匹配高温氟盐堆的SCO₂系统冷端变工况运行特性研究

The small power generation system of supercritical carbon dioxide (SCO₂) 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 off-design 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 SCO₂ 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 SCO₂ 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 SCO₂ cycle when the ambient temperature changes.