CFD Simulations Of Ethylene Cracking Furnace's Burner

Ethylene cracking furnace is the core device for the ethylene production, while the burner is the most important component which used to generate heat. Large amounts of data can be acquired by simulating the various processes through the establishment of mathematical models, which provide necessary information to improve pyrolysis technology.In this paper, a single burner was chosen for the study using GAMBIT and FLUENT software as a platform; the appropriate mathematical model was selected according to the actual industrial process, to describe some phenomena happened in the furnace such as fuel gas movement and distribution of the species.First of all, the geometry model was established using GAMBIT software, the calculation domain was meshed, the mathematical model was established, and the discretization method was chosen. Then, the numerical results of five different combustion models, ED model, EDC model, the finite rate/eddy dissipation model, non-premixed combustion model and composition PDF transportation model, were compared ignoring radiation. It was concluded that the most suitable combustion model for the industrial situation is finite rate/eddy dissipation model.The influences of inlet velocity and calculation domain were investigated in this paper. The influence of the rate on the combustion was compared at the speed of 50m/s, 100m/s, 200m/s, 300m/s and 409m/s. At the same time, the calculation domain was extended about 0.5m along the X direction to examine the impact of the calculation domain on the combustion.Finally, two radiation models, P-1 radiation model and DO radiation model, were selected to determine the impact of radiation on the combustion. The results indicated that: although the turbulent reaction rate is significant for the turbulent combustion, chemical reaction and interaction between the radiations become important after the radiation model was added, different radiation models have different roles.