Coupled simulation of an industrial naphtha cracking furnace equipped with long-flame and radiation burners

A coupled reactor/furnace simulation has been conducted for a 100 kt/a SL-II naphtha cracking furnace containing both long-flame and radiation burners. The computational fluid dynamics approach was used to simulate the flow, combustion and radiative heat transfer in the furnace. The software packages COILSIM1D and SimCO were used to account for the cracking process in the reactor coils. The simulation provides for the first time detailed information about concentration, velocity, and temperature fields for these types of furnaces. Comparison of the calculated product yields against measured industrial data validates the simulation and shows that the difference with using a predefined normalized heat flux profile is limited. The results show that the design of radiation section outlet leads to an asymmetric flue gas-temperature, concentration and velocity profile. Large recirculation zones exist near the reactor tubes, making the temperature in the middle of furnace more uniform.

► A cracking furnace is simulated containing both radiation and long-flame burners
► For the first time detailed information is provided for these types of furnaces.
► Good agreement is obtained between the simulation results and the industrial data.
► This approach provides a theoretical basis for the optimization of cracking furnace.