Influence of flow rate, temperature and pressure on multiphase flows of supercritical carbon dioxide and water using multivariate partial least square regression

Abstract

Supercritical carbon dioxide (scCO 2 ) is often used to replace harmful solvents and can dissolve a wide range of organic compounds. With a favorable critical point at 31 °C and 7.4 MPa, reaching above the critical point for scCO 2 is fairly accessible. Because of the compressible nature of scCO 2 and the large changes of viscosity and density with temperature and pressure, there is a need to determine the behavior of scCO 2 in microfluidic systems. Here, the influence of how parameters such as flow rate, temperature, pressure, and flow ratio affects the length of parallel flow of water and scCO 2 and the length of the created CO 2 segments are investigated and modeled using multivariate data analysis for a 10 mm long double-y channel. The parallel length and segment size were observed in the laminar regime around and above the critical point of CO 2 . The flow ratio between the two fluids together with the flow rate influenced both the parallel length and the segment sizes, and a higher pressure resulted in shorter parallel lengths. Regarding the segment length of CO 2 , longer segments were a result of a higher Weber number for H 2 O together with a higher temperature in the channel.

Thin film metal sensors in fusion bonded glass chips for high-pressure microfluidics

“…To control such a fluid systems, it is necessary to have precise control of the temperature. The large surface to volume ratio in microchips allows for good heat transfer and common approaches for external temperature control includes having chips mounted on heated Cu blocks [19], immersed in oil [20] or mounted on resistive heat stages [21]. For all such systems, the temperature is measured externally and globally.…”