Study On Simulation Of Pulverized Coal Gasification Process

Coal gasification technology is a process that converts coal into a combustible gas, as clean coal technology and new energy key technologies. Coal gasification is strongly advocated technology by national.In this paper, A model of entrained-flow coal gasifier(1920 t/d and single nozzle) was established to simulate the process of pulverized coal on the basis of the ANSYS/FLUENT 12.1 software. The CFD numerical models were constructed to simulate the characteristics of the process of coal gasification. and the devolatilization model, particle surface reaction model, chemical reaction model, turbulent model and radiation model are considered in this simulation. There are three groups of heterogeneous chemical reactions and five groups of homogeneous chemical reaction for the gasification reaction. The standard k-epsilon turbulence model was applied to the gas phase flow. The lagrange model was adopted to obtain properties of particles. Meanwhile, the species transport model and modified Eddy-Dissipation Model (EDM) were used to simulate the species transport and gas phase reaction, respectively. Radiation heat transfer was modeled with the P1 model inside the furnace. The coal from Ningdong factory and the actual production process of gasification conditions as the basic parameters of the simulation. Radiation heat transfer was modeled with the P1 model inside the furnace. The coal from Ningdong factory and the actual production process of gasification conditions as the basic parameters of the simulation. The results show the velocity distribution, temperature and concentration field distribution of the syngas. Flow field inside GSP gasifier can be divided into four zones: the rotary spray zone, internal recirculation zone, external recirculation zone and plug flow zone. Oxidation zone is mainly in the rotating jet and internal recirculation zone. Gasification reaction stronger than the other regions, the temperature distribution is more uniform in these zones. Numerical results agree well with the corresponding actual production data. This work also explores the effects of pressure, temperature, oxygen-coal ratio and steam-coal ratio on the basis of this reasonable model. Increasing the gasification pressure has been strengthen the chemical reaction, but has little effect on the final gas composition. The volume fraction of CO and H2 increased significantly if the temperature increases. The best coal-oxygen ratio range is 0.70～0.85 for this gasifier and coal. Steam-coal ratio should not be too high or too low, Must be combined with actual operating conditions of the gasification to select the appropriate range. These studies can provide a reference for the optimization design of the gas of the processcontrol and the structure of the gasifier.This work is to optimizing control of gasification process for engineering and to put forward the theoretical data support for the actual production of coal gasification and gasifier improvements, also significance for equipment structure and production process.