Pollutant Emission Diagnosis And Burner Optimization Design Of Aviation Kerosene Hydrogenation Furnace

With the continuous expansion of industrial production scale,the problems of environmental pollution and energy shortage are becoming more and more serious.The petrochemical industry has increasingly stringent requirements for green and low carbon,energy saving and emission reduction.The furnace takes plenty of energy consumption and is one of the significant pollutant emission sources.This paper takes the energy saving and emission reduction of the reaction feed furnace of an aviation kerosene hydrogenation unit in a petroleum refinery as the research target and uses the CFD technology to simulate the combustion characteristics of the existing burner and the new environment-friendly burner.And the operating parameters of the new environment-friendly burner are optimized.In order to analyze the reasons for the excessive emission of pollutants from the existing reaction feed furnace,the combustion of the existing burner and its furnace was simulated.The calculation result shows that:(1)The relative errors between the calculation result and the measured values are less than 10%,which verifies the reliability of the mathematical model and calculation result;(2)The temperature distribution in the furnace is non-uniform and there is a local high temperature zone,which is an important reason for NOx emission,and the NOx concentration at the outlet of the furnace is 69mg/m~3.(3)The unreasonable proportion of fuel classification leads to the short residence time of fuel in the combustion zone.Incomplete combustion of primary fuel is an important cause of excessive CO emissions,and the CO concentration at the outlet of the furnace is 3089mg/m~3.Aiming at the problems existing in the existing burners,combined with the principle of staged combustion,a new three-stage cylindrical flame burner was proposed.The new burner and its furnace were numerically simulated.The calculation result shows that:(1)The first-stage flame of the new burner is straight upward,the second-stage and third-stage flames are distributed in multiple points,the uniformity of the temperature field is improved,the occurrence of local high-temperature areas is avoided,and the generation of NOx is reduced;(2)The use of three-stage combustion makes the fuel-gas mixing and combustion more sufficient and reduces CO emission;(3)The NOx emission concentration at the furnace outlet of the replacement of the new environment-friendly burner is 25.0mg/m~3,which is 62.12%lower than that of the existing burner;The CO emission concentration dropped from 3089mg/m~3 to11.5mg/m~3.The influence of operating parameters on the combustion characteristics of the new environment-friendly burner is also studied in this paper.The effects of the proportion of classified fuel,excess air coefficient and air preheating temperature on the temperature field and pollutant formation were investigated.The result shows that the best combustion effect can be achieved when the fuel ratio of the central gun to the ring gun of the new environment-friendly burner is 30:70,the excess air coefficient is 1.15 and the air preheating temperature is 330K.