Numerical study of combustion performance on an after-treatment burner at different equivalence ratios

• The turbulent kinetic energy in the burner presents a three-stage distribution. • The peak value of emissions occurs in the combustion tube. • The thermal efficiency reaches 71.26% when the equivalence ratio is 2.4. • The overall performance of the burner is better when the equivalence ratio is 2.0. The after-treatment burner can realize the regeneration of diesel particle Filter (DPF) under the cold start condition, which shows strong potential applications to cope with the Euro Ⅶ emission regulations. To ensure the stability of the burner during DPF regeneration, it is the key to grasp the influence law of burner control parameters on its performance. However, there is still a lack of research on the combustion performance of after-treatment burner under cold start condition. The flow field, combustion and emission characteristics of the burner are investigated by numerical simulation methods under the lean and rich fuel combustion conditions with the aim of improving the active regeneration efficiency of burner-type DPF. The results show that the high temperature zone in the burner is generated faster under the lean combustion condition, but the thermal efficiency of the burner lowest, only 61.34%. And the thermal efficiency decreases gradually with the decrease of equivalence ratio. Soot emissions increase sharply in two stages, and with the decrease of the equivalence ratio, the peak value of the soot emission from mix chamber gradually moves towards the combustion tube. It is worth pointing out that the performance of the burner is better when the equivalence ratio is controlled to 2.0. These conclusions provide a reference for the accurate control of the burner in the subsequent DPF active regeneration process.