Research On Physical Field Simulation And Working Condition Optimization Of Dry Quenching Furnace Based On COMSOL Multiphysics

The 140 t/h CDQ in a coking plant is taken as the research object.Through on-site testing of CDQ operating parameters,the fluid resistance,airflow velocity and coke burnout rate in the CDQ furnace are calculated to understand the relationship between process parameters and coke burning loss rate under normal production conditions.On this basis,with the help of COMSOL Multiphysics software,the physical field in the CDQ furnace is simulated and calculated,and the change characteristics of the flow field,temperature field and reaction field in the CDQ furnace are analyzed.The method of controlling variables is to study the influence of changes in circulating air volume,inlet air temperature,inlet gas CO concentration,and coke layer porosity on the physical field,heat transfer and coke burning loss in the dry quenching furnace.The results show that:(1)Field tests show that the process parameters of the dry quenching furnace under normal production conditions are the circulating air volume of 180,000 m~3/h,the average air velocity of 2.2 m/s,the porosity of 0.56,the coke layer resistance of268.86 Pa/m,and the furnace gas temperature of 166℃,the inlet gas CO concentration is 5%.At this time,the coke burnout rate is 1.95%>design value 1.0%.The coke burnout rate increases with the increase of gas-to-battery ratio,coke discharge temperature,gasification rate,and material level,decreases with the increase of the inlet gas CO concentration.(2)Multi-physics simulation calculations show that the pressure in the dry quenching furnace shows a decreasing phenomenon from bottom to top,0 Pa appears in the upper part of the cooling chamber,and the top of the cooling chamber and the pre-storage chamber are in a slightly negative pressure state,about-126 Pa;The speed is fast in the periphery and slow in the middle;the temperature distribution of the cooling chamber is high in the middle and low in the periphery;the combustion reaction of coke and oxygen occurs in the lower part of the cooling chamber of the dry quenching furnace,and the water gas reaction between coke and steam and carbon dioxide occurs at the upper part of the cooling chamber above 800 K As the coke reaction in the cooling chamber progresses,the CO concentration continues to accumulate.(3)The research results of the control variables show that with the increase of the circulating air volume,the coke temperature in the dry quenching furnace decreases at a faster rate,the overall temperature of the cooling chamber decreases,and the coke burn rate also increases.The combustion reaction of coke,water gas reaction and carbon dissolution The loss reaction increases;with the increase of the circulating gas inlet air temperature,the coke discharge temperature increases,and the coke burning loss rate tends to increase,but does not change the temperature distribution characteristics in the cooling chamber;the reduction of the porosity of the coke layer is conducive to heat transfer,but cooling The indoor temperature changes unevenly,and the outlet pressure of the fan increases,and the coke burning rate increases;the increase of the inlet gas CO concentration is conducive to reducing the coke burning loss,and the CO concentration can be appropriately increased,but the CO concentration cannot be higher than the 12.5%lower explosive limit.(4)The simulation calculation shows that when the circulating air volume of the dry quenching furnace is 150,000 to 160,000 m~3/h and the coke layer porosity is about0.6,it is conducive to the cooling of the coke in the dry quenching furnace and the reduction of the burning loss rate.