Dynamic Simulation Of Coal Water Slurry Gasification Under Abnormal Conditions

Coal gasification technology has become the core of modern coal chemical technology with its many advantages,but the gasification process is easily affected by many uncertain factors in the actual production process,which pose a threat to the smooth operation of equipment and the safety of personnel,restricting the production and technological development of the coal chemical industry.Based on the coal water slurry gasification process,the abnormal working conditions of gasification process are analyzed and studied by establishing a gasification system model.Comprehensively considering the opposed multi-burner coal-water slurry gasification process and the flow field and chemical reaction characteristics in the gasifier,a coal-water slurry gasification process model was established.The model calculation results were approximately consistent with industrial data,which verified the effectiveness of the model.On this basis,the response of the gasification temperature and the syngas water-gas ratio under small fluctuations in coal water slurry flow rate and concentration and oxygen flow rate were analyzed.Morris method and RSM method were used to study the sensitivity of gasification parameters and the interaction of sensitive parameters.Firstly,a sensitivity analysis was carried out for the main parameters affecting the coal gasification process:coal water slurry flow rate,coal water slurry concentration,oxygen flow rate,circulating ash water flow rate,and condensate flow rate,and the sensitive parameters that have a greater impact on the safe operation of the gasification system were selected.The influence of sensitive parameter interactions on the gasification results was studied by RSM method.By limiting the safe range of the gasification temperature and the syngas water-gas ratio,the safe operating boundaries of the parameters were obtained.The fault tree analysis method was used to analyze the causal relationship between gasifier over-temperature and basic events,and it was determined that the oxygen-coal ratio and the coal water slurry concentration were the main parameters that cause the over-temperature of the gasifier.The ultrasonic test method was used to measure the concentration of coal water slurry online,which proved real-time measurability of coal water slurry concentration.On this basis,a dynamic model of coal water slurry gasifier was established,and then the method of combining dynamic simulation with HAZOP was used to simulate and analyze the abnormal change of oxygen-coal ratio and coal water slurry concentration,the dynamic response law of gasification temperature and the safety deviation range of gasification parameters were obtained.