超临界CO₂临界流实验研究

Experimental Study on Critical Flow of Supercritical CO₂

摘要: 以超临界二氧化碳工质的动力转换系统发生破口时，由于系统内处于高压状态，破口处会发生临界流现象，对核电系统的安全运行产生了巨大的威胁，分析超临界二氧化碳临界流动对该系统安全分析十分重要。建立超临界二氧化碳临界流实验装置，实验研究超临界二氧化碳临界流现象，比较上游滞止温度、上游滞止压力和长径比对临界流量的影响规律，获得实验数据库。实验发现，二氧化碳质量流量随着上游滞止温度和长径比的增加而减小，随上游滞止压力的增加而增加。对典型实验现象进行分析，探讨了超临界二氧化碳在管内的临界流机理，实验结果为进一步开展实验研究和理论研究提供支持和参考。

Abstract: The power conversion system of supercritical carbon dioxide is the frontier of the current inter-national energy and power field. When the system is broken, the critical flow phenomenon occurs at the high temperature and high pressure in the system, and the safety of the nuclear power system operation has produced a huge threat, analysis of supercritical carbon dioxide critical flow of the system safety analysis is very important. The critical flow of supercritical carbon dioxide was studied by establishing a supercritical carbon dioxide critical flow experimental device. The influence of upstream stagnation temperature, upstream stagnation pressure and aspect ratio on critical flow was compared. It was found that the mass flow rate of carbon dioxide decreased with the increase of upstream stagnation temperature and aspect ratio, and increased with the increase of upstream stagnation pressure. The typical experimental phenomena are analyzed and the critical flow mechanism of supercritical carbon dioxide in the tube is discussed. The experimental results provide support and reference for further experimental research and theoretical research.