Design and Validation of Silicon Carbide Diesel Particulate Filter with High Effective Filtration Area 2020-01-5044
The effective filtration area of a diesel particulate filter (DPF) can be improved by novel cell structure design and valuable plugging layout simultaneously without sacrificing the reduction of the inlet aperture ratio. A prototype silicon carbide DPF characterized with about more than 14 cm2/cm3 filtration area and more than 43% of the inlet aperture has been designed, optimized, and manufactured. Based on a single-cylinder diesel engine test bench, the performance of this prototype has been evaluated, such as its filtration efficiency, pressure loss, active/passive regeneration efficiency, etc. Upon comparing the conventional 200 cells per square inch (CPSI) with 300 CPSI DPFs with square cell structure, this prototype shows some advantage of pressure loss in the conditions with higher soot loading, and its filtration efficiency can compete with previously designed counterparts, but its active regeneration efficiency is lower than that of 300 CPSI DPFs with square cell structure and normal plugging layout alike. This prototype is characterized by a trade-off performance. Finally, the catalytic coating accommodation for this prototype with a diameter size of 10.5″ and length of 6″ has been evaluated and, due to its unique plugging layout, could pose some challenge for coating a uniform layer on the surface of the filtration wall. A molten alkali metal sulfate catalyst technology has been applied for this purpose, and the scanning electron microscopy (SEM) results of a catalyst substrate surface and cross-section show that the coating layer adheres to the filtration wall surface very well. The further performance of regeneration efficiency has been evaluated based on a Cambustion DPG equipment (DPF Testing System), and its particle number control under cold/hot WHTC based on a 4.8 L diesel engine test bench has been evaluated; this prototype with an optimized cell structure DPF and diameter size of 10.5″ and length of 6″ can effectively control the particle number emission from a diesel engine.