Numerical simulation study on soot continuous regeneration combustion model of diesel particulate filter under exhaust gas heavy load

摘要

Soot continuous regeneration combustion under exhaust gas heavy load is effective regeneration method without additional facilities and equipment. In this study, 3D soot continuous regeneration combustion model under exhaust gas heavy load is proposed with UDF function of FLUENT software. FR (Forbid Rate), ED (Effective Definition Rate) and EDC (Effective Definition Calibration Rate) model of different O-2 concentration coefficient and soot concentration coefficient are applied for simulation study of soot fast oxidation regeneration reaction and slow reaction. The soot regeneration combustion efficiency, dynamism performance, pressure field and thermal effects of soot combustion reaction are investigated to evaluate the simulation results. 3 models can achieve the complete soot continuous regeneration with the regeneration efficiency over 88% under the pressure drop of 2 x 10(4) Pa which is consistent with the experimental results. EDC model has higher turbulent kinetic energy (= FR of 48.75 J model and = ED of 49.01 J) and lower Reynolds number which is more suitable for the condition of stable laminar flow state. The temperature of EDC model is higher than that of ED and FR models with the maximum temperature difference of 265.4 K (inlet), 24.7 K (filter body) and 8.4 K (outlet). The results showed that EDC model are more consistent with the experimental data which has obvious good qualities and preponderance of soot regeneration combustion efficiency, dynamism performance, pressure field and thermal effects. EDC model is more appropriate for simulation study of soot continuous regeneration reaction under exhaust gas heavy load which is the rapid oxidation regeneration.