Effect of engine operating conditions on soot layer permeability and density in diesel particulate filters

Abstract

Understanding the variation of soot deposit properties in diesel particulate filters is necessary for their real-life modeling and onboard control. In this study, the effect of exhaust mass flow rate and particle agglomerate size on the soot layer permeability and density was investigated experimentally and analyzed using a well-validated model. A bare and a coated diesel particulate filter were loaded at five different engine operating points, specially selected to explore these effects in a heavily used part of the diesel engine map. Particle emissions were characterized in terms of particle agglomerate size distribution and primary particle diameter, while soot layer permeability and density were estimated indirectly by fitting the model to the pressure drop recordings. To this end, an automatic calibration procedure was applied to obtain values in a consistent and repeatable manner. The results showed considerable variation in both permeability and density. Furthermore, some trends could be identified after depicting the particle characterization data and soot layer properties in contour plots. Increased permeability appeared at the engine operating point with high flow rate and large particle agglomerate size. Lower density was obtained at the operating points with large particle agglomerate diameter.

Diesel particulate filter regeneration mechanism of modern automobile engines and methods of reducing PM emissions: a review

“…In addition, due to different engine operating conditions, the same soot load level may have different soot distribution. This may cause regeneration hot spots and uneven heat transfer (Zöllner et al 2019 ). Therefore, it becomes important to develop a stable soot estimation model.…”

“…The mainstream method is to predict soot load through pressure drop model (Zöllner et al 2019 ). In terms of capture mechanism, the capture process of DPF is mainly divided into two stages: deep bed filtration and cake filtration (Wang et al 2021a ).…”

Filtration efficiency and pressure drop modelling of particulate filters with rear plug damage

“…Deposit density and other properties are a function of the filtration conditions and particle characteristics. 40,54,55 A packing density ρ t is used here to characterize the skin layer formed by the instantaneously collected PM. This parameter differs from density ρ c which is an average value for the whole thickness of the cake.…”

“…Similar values have been reported for most parameters in the past. 40 An empirical value was used for d slip . Figure 6(a) presents the pressure drop measurement and calculation.…”

Enabling robust simulation of polyoxymethylene dimethyl ether 3 (PODE3) combustion in engines

“…[2][3][4] As such, vehicular emission regulations have been regularly updated 2 to put a check on these harmful emissions. In order to allow direct injection compression ignition (DICI) engines pass strict EURO VI requirements, 5 exhaust improvement methods such selective catalyst reduction 6 and diesel particulate filter 7,8 are often employed. These aids are not without shortcomings, which include inefficiency resulting from backpressure and complexity of the vehicle design.…”