“HRT”非对称孔道颗粒捕集器压降特性

Pressure drop characteristics of the hexagon rectangle triangle(HRT)-type asymmetric channel particulate filter

为有效控制颗粒捕集器压降,延长清灰里程,本文提出了一种“HRT”非对称孔道结构颗粒捕集器。搭建了“HRT”非对称孔道和其他类型孔道的一维计算模型,对比分析了颗粒捕集器孔道内流动及压降变化情况。研究结果表明:不同孔道边长比下“HRT”非对称孔道结构的压降性能存在一定差异,孔道边长比为3.0时压降性能最好,且孔道内碳烟分布均匀;HRT3.0结构能够有效增加过滤壁面表面积和过滤壁面容积占比,有利于降低过滤壁面压降和滤饼层压降;不同排气流量下HRT3.0结构的压降性能均优于SQ和SQ1.4结构,排气流量越大HRT3.0结构的绝对压降下降越多。在发动机额定工况下,当碳载量为8 g/L时,HRT3.0结构的总压降比SQ结构低20.9%,比SQ1.4低9.4%。

In order to effectively control the pressure drop and prolong particulate filter service life,an HRT-type,asymmetric structure particulate filter is proposed.One-dimensional computational models of the HRT-type asymmetric channel and other types of channels are established,and the flow and pressure drop characteristics of those channels are compared and analyzed.The results show that the pressure drop performances of the HRT-type asymmetric structures are different under different ratios of channel side length.They demonstrate that the best pressure drop performance is reached when the channel side ratio is 3.0,and the soot distribution in the channel is uniform.HRT3.0 structure can effectively increase the proportion of filtration wall surface area and its volume,which is conducive to reducing the pressure drop of the filtration wall and soot layer.The pressure drops of the HRT3.0 asymmetric structure are lower than those of the symmetric and asymmetric structure under different exhaust fluxes,and the absolute pressure drop reduces more of the HRT3.0 asymmetric structure under greater exhaust flux.When engines are underrated conditions and the soot load is 8 g/L,the total pressure drop of HRT3.0 structure is 20.9%lower than that of the SQ structure and 9.4%lower than that of the SQ1.4 underrated conditions.