壁流式过滤体的流动阻力分析及再生效率研究

分析了工作中的壁流式过滤体的流动阻力,指出过滤过程中,当小孔壁面上的PM滤饼形成后,排气流经壁流式过滤体时的压力降低主要由过滤体小孔壁面、PM层、入口和出口小孔通道等4处的流动阻力产生,其中前两处的流动阻力起主要作用。给出了过滤体再生效率的两种定义,并分析了其差别,指出对相同结构的过滤体,可以用再生前后排气流经过滤体的压差计算其再生效率;对不同结构的过滤体用该定义评价再生效率时,应考虑由于过滤体自身结构参数的变化引起的再生效率的变化。

Flow Resistance Analysis of Wall-Flow Filter and Study of it's Regenerative Efficiency

The flow resistance of wall-flow filters on operation is analyzed.It shows that the pressure drop of wall-flow particulate filter is caused by four flow resistance,they are flow resistance of porous filter wall,of particulate cake,of inlet and outlet channels respectively.Two definition of filters' regenerative efficiency are given,and their difference is studied.It is showed that for filters with the same structure,their regenerative efficiency can be evaluated by the filter's pressure drop before and after regeneration,while for filters with different structure,the changes of regenerative efficiency caused by the structural parameters should be considered.