Study of the slippage of particle/supercritical CO2 two-phase flow

• Published in: The Journal of supercritical fluids Vol. 120; pp. 173 - 180
• Main Authors: Hou, Lei, Sun, Baojiang, Geng, Xueyu, Jiang, Tingxue, Wang, Zhiyuan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2017
• Subjects: Analytic calculations; Slippage behavior; Supercritical CO2; Two-phase flow; Visualization experiments; Visualization experiments; Slippage behavior; Two-phase flow; Supercritical CO2; Analytic calculations
• ISSN: 0896-8446; 1872-8162
• DOI: 10.1016/j.supflu.2016.09.016

[Display omitted] •Particle-SC-CO2 two-phase flow experiments have been performed.•Particle slippage in SC-CO2 is similar to a liquid.•Analytic calculations of slippage velocity and displacement have been derived.•The density of SC-CO2 exerts a greater influence than the viscosity on the slippage. In this paper, the slippage velocity and displacement between particles and supercritical CO2 (SC-CO2) were studied to reveal the particle-SC-CO2 two-phase flow behavior. Visualization experiments were performed to directly measure the slippage velocity and displacement. Eight groups of experiments involving various pressures (7.89–10.96MPa), temperatures (38.6–47.5°C), particle diameters (0.3–0.85mm), particle densities (2630 and 3120kg/m3) and SC-CO2 flow rates (0.920–1.284m/s) were conducted. The measured particle slippage velocities in the flowing direction were approximately 10.3% of the SC-CO2 flow rate. The measured particle slippage displacements were all at the centimeter level, which indicated that SC-CO2 had a superior particle transporting capability that was similar to those of liquids even if it had a low viscosity that was similar to those of gases. A numerical model was built, and analytic slippage calculations were performed for SC-CO2 for additional analyses. The density of SC-CO2 was found to have a greater influence on the slippage than the viscosity. Moreover, a comparison of the slippage between SC-CO2 and water showed that the particle slippage in water was constant, while the particle slippage in SC-CO2 continually accumulated at an extremely slow rate.