Indexed by:期刊论文

Date of Publication:2019-08-01

Journal:INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER

Included Journals:SCIE、EI

Volume:139

Page Number:1087-1095

ISSN No.:0017-9310

Key Words:Density-driven convection; Finger; Dissolution rate; Large Ra; CO2 storage

Abstract:In this study, we visualized density-driven convection in an improved Hele-Shaw cell at 25 degrees C and 0.1 MPa by examining the convection mixing process of analogous fluids and total dissolution rates in the high Rayleigh number (Ra) region. The high Ra number was inspired by data referring to the geological reservoir at the Sleipner site. We investigated the effect of the density difference between different fluid pairs on the initial moment and development of convective mixing. Though direct imaging and processing, we examined the convective mixing development regime, finger number density, onset time and movement speed of fingers. The fingering instability and mixing time of miscible fluids were also analysed and show that as the density difference increases, the density of the finger number increases and the fingers quickly merge. The onset time decreases sharply and then becomes stable and is inversely proportional to Ra-2. The convection mixing time has the same tendency but is inversely proportional to Ra. Moreover, the finger speed linearly increases and is directly proportional to the characteristic velocity. The dissolution rate was investigated with the dimensionless convection flux Sherwood number (Sh) and shows a power law relationship with Ra. The density difference accelerates the dissolution rate. The experimental conditions were different from those of real CO2 geological storage, but this study has implications for predicting the CO2 dissolution trapping time and accumulation for geological storage of carbon dioxide. (C) 2019 Elsevier Ltd. All rights reserved.