Abstract
Supercritical CO2 pipelines usually are used to link the CO2 capture system to the geological storage. There are severe hazards once the asphyxiating gas leaks from the long-distance pipeline. The uncertainty of near-field jet characteristics results in imprecise consequences assessment of accidental release of supercritical CO2. To improve the prediction of consequences of accidental release accuracy, the near-field mechanisms of flashing-spray jet was investigated. In this work, an experimental setup with multiple measurement instruments was developed to impose controllable CO2 release from a high-pressure vessel. The flashing-spray jet structures of supercritical CO2 from circular and rectangular orifices were recorded by a high-speed camera. Results indicate that the near-field structures of supercritical CO2 jet from circular and rectangular orifices are totally different, which causes the different dispersion consequences. The jet angle and shock waves were analyzed quantitatively. Lastly, the models of flashing-spray based on the two different phenomena from rectangular and circular orifices were discussed. The combination of macroscopic and microscopic data in the jet can help to understand the complex physics and improve discharge and dispersion model. This work provides a fundamental data to consequences assessment of accidental release of supercritical CO2.
Highlights
Carbon dioxide (CO2) as a major greenhouse gas (GHG) has increased significantly impacts on the earth owing to human activities such as burning of oil and gas and the discharge of exhaust gases
This study provides a viable method for assessment of risks associated with Carbon Dioxide Capture and Storage (CCS). (Wareing et al, 2013a) present a composite equation of state accounting for the three-phase CO2 in the modeling of liquid CO2 release
It can be called “ExpansionContraction-Expansion Configuration (ECEC).”. It can be obviously seen from Figure 4; Figure 5 that the shape of jet of supercritical CO2 released from a rectangular orifice is very different from that release from a circular orifice, which may cause the difference of dispersion region
Summary
Carbon dioxide (CO2) as a major greenhouse gas (GHG) has increased significantly impacts on the earth owing to human activities such as burning of oil and gas and the discharge of exhaust gases. Due to a lack of experimental data in supercritical CO2 releases focusing on near-field characteristics, currently the development of more complex models is limited. The under-expanded jet flow structure and phase transitions in the near-field were studied for supercritical CO2 released though different orifice diameters. An experimental setup with a high-speed camera system was designed and constructed to study the near-field characteristics of flashing-spray jet of supercritical CO2 from various orifice geometries. The work focused on (1) the near-field structures during CO2 released from different orifice geometries; (2) the evolution of jet angle which can affect the dispersion region; (3) the shock waves system in the release from orifices with different geometries; (4) models of the flashing-spray jet of supercritical CO2
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
