Leakage of carbon dioxide (CO₂) vessel can significantly affect the safety in the field of carbon capture and storage technology (CCS). Studies of small rupture leakage in the early accidental release stage are required. In this study, to investigate the release from small rupture under different working conditions, an experimental CO₂ blowdown device was presented, transient pressure and mass flow rate were respectively measured and calculated, and also a pressure vessel release model was built. Besides, homogeneous model and phase separation model were employed to analyze the phase distribution in the vessel. According to the experiment results, the phase separation model shows a better applicability in small scale rupture leakage. The effect of initial pressure on pressure release is not obvious, while the effect of the initial temperature and nozzle location on pressure release is significant. When nozzle is located in the bottom of the vessel, pressure release becomes faster and more dangerous.

二氧化碳（CO ₂）容器的泄漏会严重影响碳捕集与封存技术（CCS）领域的安全性。需要研究意外释放早期的小破裂泄漏。在这项研究中，为了研究在不同工作条件下小破裂的释放，我们采用了实验性的CO ₂提出了排污装置，分别测量和计算了瞬态压力和质量流量，并建立了压力容器释放模型。此外，采用均质模型和相分离模型分析了容器中的相分布。根据实验结果，相分离模型在小规模破裂泄漏中显示出更好的适用性。初始压力对压力释放的影响并不明显，而初始温度和喷嘴位置对压力释放的影响却很明显。当喷嘴位于容器底部时，压力释放会变得更快，更危险。