A HYBRID NUMERICAL MODEL OF LCO{sub}2 AND CO{sub}2 ENRICHED SEAWATER DYNAMICS IN THE OCEAN INDUCED BY MOVING-SHIP RELEASING

摘要

Based on engineering background of direct disposal of liquid CO{sub}2 into the ocean by a moving ship, a numerical model is developed to simulate and predict the physicochemical dynamics of LCO{sub}2 droplets and CO{sub}2 enriched seawater in the ocean. This is a hybrid model consisting of a 3-D small-scale near-field model and a 2-D horizontal turbulent dispersion model. The double-plume formation, interaction, evolution, and coupling with ocean current, are described by using two-fluid large-eddy simulation technology. The further development of CO{sub}2 enriched seawater, as a passive-inert scalar, in relative larger space and time scales (28 × 28 km and up to 100 hours) is then simulated by the horizontal turbulent dispersion model. For case of LCO2 releasing at depth of 2200m with mass flow rate of 100 kg/sec, initial droplet diameter of 8.0 mm, and ship speed of 3.0m/sec, modeling results predicted that it produces a locally minimum pH of 6.20 associated wit the CO{sub}2 concentration of 0.18 kg/m{sup}3, a vertically separated CO{sub}2 enriched seawater plume with 330m in height and 40m in wide at time about one hour after releasing. This CO{sub}2 enriched seawater plume converted and diffused turbulently in horizontal surface to an area in horizontal of 9.8 × 10.5 km{sup}2 in 100 hours later.