DPF喷油助燃装置工作参数对再生过程的影响

以喷油助燃再生方式为例，基于柴油机微粒捕集器（DPF）过滤体孔道热再生模型，对喷油助燃再生装置在不同工作参数下即喷油压力、喷油率、补气量等单因素变化时对再生过程过滤体排气背压、孔道内微粒层厚度及壁面峰值温度等变化规律进行了研究与分析.结果表明：燃烧器的工作参数喷油压力、喷油率、补气量等对再生过程有显著影响.随着喷油压力的提高，过滤体孔道再生壁面峰值温度升高，加快再生速率提高喷油率可加大燃烧器的功率，再生过程壁面峰值温度增幅较大，从过滤体的安全耐热温度来看应加以控制，但喷油率提高到一定程度后，使排气中氧含量不足，燃烧器燃烧效率下降，且影响微粒的氧化速度，导致再生速率随之下降.适当补气可增加排气中氧含量，可加快再生过程，但进一步加大补气量后由于对流传热散失作用加强将减缓再生过程.

Study of the Impact of the Working Parameters of a Burner-type DPF on Regeneration

Taking a burner-type diesel particulate filter (DPF) as an example and based on the pyrogenation regeneration model, the variety laws of the exhaust back-pressure, particulate layer thickness and wall maximum temperature, etc.during the burner-type DPF regeneration were studied and analyzed under different working parameters, such as oil-spray pressure, spray rate and air-supply flux.The results indicate that the working parameters could influence the regeneration evidently.With the improvement of the oil-spray pressure, the wall maximum temperature increased markedly, and the regeneration rate was quickened.The burner power became stronger with the increase of oil -spray rate, and the amplitude of the wall maximum temperature was greater.But for the safe endurable temperature of DPF, the oil-spray rate must be controlled.When the oil-spray rate reached a certain extent, the oxygen content in the exhaust was deficient, the combustion efficiency decreased, and the soot oxidation velocity and regeneration rate slowed down.It increased the oxygen content by air supply and the regeneration process quickened.But with more air-supply quantity, the regeneration may slow down because of the enhancement of convection transfer heat loss.