Molecular dynamics simulation of carrier gas pressure affecting water vapor nucleation

To explore the nucleation mechanism during supersonic natural gas dehydration, the effect of carrier gas pressure on water vapor nucleation is studied using molecular dynamics. Using the TIP4P / 2005 water model and considering the effect of impurity particles, the effect of carrier gas pressure on homogeneous and heterogeneous nucleation of water vapor, and the effect of carrier gas pressure on nucleation at different water vapor temperatures and particulate matter diameters are studied. The results show that at a water vapor temperature of 323 K, the nucleation rates corresponding to carrier gas pressures of 0. 043, 0. 081 and 0. 170 MPa are (3. 93 ± 0. 21) × 1032 , (4. 51 ± 0. 35) × 1032 and (8. 14 ± 0. 41) × 1032 m - 3 ·s - 1 , respectively. The increase of carrier gas pressure promotes both homogeneous and heterogeneous nucleation. The increase of water vapor temperature weakens the promotion of carrier gas pressure on nucleation, and the homogeneous nucleation is inhibited due to the decrease of supersaturation, and due to vapor competition between homogeneous and heterogeneous nucleation, heterogeneous nucleation gradually dominates in the vapor competition with the increase of temperature. The increase of particle diameter can greatly promote heterogeneous nucleation. The promotion of heterogeneous nucleation by carrier gas pressure is observed with the increase of particle diameter. © 2024 Southeast University. All rights reserved.