| A mathematical model of gasification chamber and dip tube was established for the single-nozzle, quench-cooling entrained-flow pulverized coal gasifier.The 1D model of entrained-flow pulverized coal gasification chamber was established based on resistance time distribution for particle phase from numerical simulation results and random pore model for reaction kinetics of char in MATLAB. The results showed agreement with those from thermodynamic model, but the simulated H2 content was lower than that in industrial data. The 1D simulation was also carried out to study the effect of oxygen-coal ratio, steam-coal ratio, heat loss, ash content and dry feeding fluctuation quantitatively.A 1D dip tube model was established in Chemkin-Pro with GRI-Mech3.0 database to investigate the influence of water quenching on syngas composition, while the evaporation rate of quench water was obtained from 2D numerical simulation involving heat and mass transfer. The simulated syngas composition at dip tube outlet was consistent with industrial data, indicating that the chemical reaction dominated by water gas shift reaction (WGSR) occurs when the syngas flowed through the dip tube.The 1D dip tube model was used to study the effect of inlet syngas temperature and flow rate of quench water on the extent of WGSR. When the temperature inside dip tube was not higher than-1346K, rarely the impact of WGSR on syngas composition could be seen at the dip tube outlet. |
PDF Full Text Request