| The cracking furnace is the core of the ethylene plant.The utilization ratio of raw materials and fuel in the cracking furnace directly affects the target product yield and overall energy consumption of the plant,and determines the economic benefits of the ethylene plant.After a long period of operation,Maoming Petrochemical Cracking Furnace has encountered problems such as reduced processing capacity,reduced thermal efficiency,short operating cycles,increased energy consumption,and poor raw material adaptability.In order to solve the above problems and adapt to the requirements of the country's new green development,this paper analyzes the reasons for the existence of problems,and simulate the cracking furnace by means of computational fluid dynamics(CFD)methods.On this basis,a reasonable reform program was adopted to improve energy efficiency and optimization of cracking furnaces.At the same time,the application of new technologies such as in-situ coating and low-nitrogen combustion in cracking furnaces of Maoming Petrochemical was studied.On the basis of a reasonable analysis of the problem to find the relevance of the problems,the comprehensive reform of the cracking furnace can better improve the overall performance.After the H-119 furnace was upgraded by updating and increasing the convection section coil,replacing the new type of radiant section furnace tube and lining,the original design capacity was restored,the thermal efficiency was improved from 91.78%to 94.28%,and the operation cycle was increased from 40 days to 85 days.In-situ coating technology is suitable for small diameter furnace tubes,which can effectively prolong the operation cycle of the cracking furnace.After the modification of the in-situ coating of H-115 furnace,the feeding load was increased by 0.8t/h,the average operation period was prolonged by nearly 30 days,and the coke removal frequency was reduced by 1.24 times/year.The new low-nitrogen burner is used in Maoming Petrochemical cracking furnace,which effectively reduces the NO_x content in the flue gas of the cracking furnace.The NO_x content was less than 90 mg/m~3,which has reached a new national emission standard.The advanced control system can effectively improve the smooth running rate of the device,reduce the energy consumption of the device and increase the yield of the target product to a certain extent.After the PID setting of the 1#cracking unit,the self-control rate was increased from 56.2%to 96.64%,the stability rate increased from 87.1%to 96.74%;and the automatic control rate of the 2#cracker was increased from 55.6%to 95.71%,the stability rate increased from 80.4%to 97.3%.The energy consumption of 1#cracking unit decreased by about 1%,and 2#cracker energy consumption decreased by about 2%before the same period.The lightening of raw materials is an effective way for crackers to reduce energy consumption and increase the yield of ethylene-propylene.The conversion of the charred gas to the furnace is an effective way to build an environment-friendly enterprise and improve the environmental protection level.1#cracking unit cracking furnace burning charcoal return furnace effectively reduces the pollutants discharged from the burning process,such as the dust and the residues of the reagents,but the charring gas access furnace will cause a certain effect on the furnace negative pressure. |
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