EPJ Web of Conferences 143, 02140 (2017)
https://doi.org/10.1051/epjconf/201714302140

Investigation of droplet nucleation in CCS relevant systems – Design and testing of a CO₂ branch of the mixture preparation device

Institute of Thermomechanics of the CAS, Dolejškova 1402/5, Prague 8, 182 00, Czech Republic

^* Corresponding authors: vins@it.cas.cz
^* censky@it.cas.cz

Published online: 12 May 2017

Abstract

A unique in-house designed experimental apparatus for investigation of nucleation of droplets in CCS relevant systems is being developed by our team. The nucleation is measured with the help of a rapid pressure drop within an expansion chamber. In this study, a CO₂ branch representing an important part of the mixture preparation device (MPD) was designed, assembled and tested. MPD is intended for preparation of CO₂-rich mixtures in a sense of accurate setting of flow rates of individual gaseous components through the experimental section with the expansion chamber. In the CO₂ branch, the saturated liquid CO₂ coming from a cylinder with a dip tube is pressurized by a supercritical pump with a constant flow rate to the pressures of up to 340 bar. The required mass flow of the supercritical CO₂ of up to 180 g/h at pressures between 74 bar and 150 bar is accurately tuned with a help of a set of stainless steel capillary tubes with inner diameter of 0.1 mm. Some of the tubes are submerged in a thermostatic bath set to a constant temperature of 70 °C in order to assure the supercritical flow conditions of CO₂. Needed lengths of the capillary tubes were determined with a help of a one-dimensional numerical model allowing prediction of both isothermal and adiabatic flow conditions.