XU Yin, JIN Baosheng. Numerical simulation and characteristic analysis for flue gas spray decarbonization[J]. Thermal power generation, 2021, 50(12): 169-178.
XU Yin, JIN Baosheng. Numerical simulation and characteristic analysis for flue gas spray decarbonization[J]. Thermal power generation, 2021, 50(12): 169-178. DOI: 10.19666/j.rlfd.202106110.
a three dimensional numerical model was established in the Euler-Lagrange framework
which couples gas-liquid flow
heat and mass transfer
and chemical reactions. A simplified thermodynamic expression is proposed based on thermodynamic consistency
and adopted in the model to reduce computational cost. The model verification result demonstrates that the predicted results agrees well with the experimental results. Moreover
the model is adopted to investigate the characteristics of gas-liquid flow
mass and heat transfer
and CO_2 absorption in the tower. The results show that
the spray mode has an important influence on gas-liquid distribution
temperature profile and CO_2 absorption in the tower. For the downward spray
the flue gas around the nozzle is entrained to flow downward in the middle part of the tower
while the fresh flue gas moves upward along the two sides of the tower. There is an intensive mixing behavior between the two gas streams.Furthermore
it is observed that the droplets aggregate in the middle part of the tower. The distributions of gas temperature
droplet temperature and H_2O gaseous volume fraction have a high correlation. The latent heat for vaporization accounts for 64% of the total gas-liquid heat exchange. The resistance to CO_2 absorption primarily exists at the liquid-side
which is two orders of magnitude higher than that at the gas-side. The maldistribution of the droplets can be mitigated by changing the spray direction
leading to an increase in the CO_2 removal efficiency from 38.3% to 49.6%.