壁流式柴油机颗粒过滤体捕集性能的实验研究

过滤压降和过滤效率是评价过滤体性能的重要指标.实验室搭建了捕集柴油机颗粒的发动机台架.通过台架实验,研究了过滤体结构参数对过滤体性能的影响.研究结果表明;随过滤体长度的增加,过滤压降逐渐减小,初始过滤效率先缓慢增加,后急剧下降;增加过滤体的孔隙率有利于降低过滤体初始压降和压降增长率;孔隙率较低的过滤体具有较高的初始过滤效率,但在颗粒层过滤阶段,孔隙率对过滤效率的影响不明显;颗粒层的沉积结构特性受过滤速度的影响,颗粒层比阻与颗粒层堆积厚度乘积的变化率随过滤速度的变化呈非线性关系变化.

EXPERIMENTAL INVESTIGATION ON THE INFLUENCE OF WALL-FLOW DIESEL PARTICLE FILTER PARAMETERS ON FILTER PERFORMANCE

Filter pressure drop and filter trap efficiency are key parameters for evaluating filter's performance. A diesel engine bench for trapping diesel particle by filter was established. The influence of filter parameters on filter performance was investigated by engine bench testing. The results show that increase in filter length decreases the filter pressure drop, the initial filter trap efficiency increases slightly at first and then decreases sharply. Increase in filter porosity decreases the initial filter pressure drop and its increasing rate. Filter with lower porosity has higher filter trap efficiency in initial loading time, while during cake filtration the influence of porosity on filter trap efficiency is not obvious. From the experimental data, it can be seen that the characteristic of deposited particle layer structure is influenced by filtration velocity, the change rate of the product of particle layer thickness and particle layer specific resistance varies nonlinearly with filtration velocity.