Particulate matter removal in automotive aftertreatment systems
Examensarbete för masterexamen
Innovative and sustainable chemical engineering (MPISC), MSc
Kannan, Ananda Subramani
There is growing concern in the world with regard to pollution and climate change. The relation between air pollution and climate change in particular is strong and complex. There is thus a shift towards greener technologies and a large amount of resources have been allocated for the research and development of such technologies. As emission regulations are becoming stricter, there is a concerted effort from all fronts in the EU to design and develop an optimal exhaust after-treatment system which would concur with current emission regulations imposed by Euro V and Euro VI (0.005 g/km of particulate matter (PM) and particulate number (PN) 6.0×1011) for both gasoline and diesel powered drives). Open channel substrates (described in this work) are used for the removal of particulate matter from exhaust. Such substrates are made of channels (arranged in a honeycomb structure) which permit the flow of exhaust through them. The PM is ultimately trapped on the wall of these channels. Over the past decade there has been a substantial increase in the computational power available to researchers. This increase of available computational resources has shifted the prime focus of research from time-consuming and expensive construction of pilot-scale prototypes towards simulation-driven development of new after treatment solutions. The current work aims to describe such a feedback between experiments and simulations in order to describe the capture of an inert particle (sodium chloride - NaCl) in an open substrate (monolith channel). The experiments and simulations are done in conjunction and such a systematic approach improves the quality of the experimental evaluation. This congruence is evident throughout this work, with the simulations generally, corresponding to the experimental results (simulations results are within the error limit of the experimental results). Both temperature and residence time have a significant impact on the capture efficiency due to Brownian deposition along an open channel. In addition the general trends with variation in residence time (flow conditions) and temperature are noticeably similar in both experiments and simulations. This indicates that the theory behind the description of capture efficiency in open channels (Brownian deposition in open substrates) is able to explain the capture phenomena of inert particulates accurately.
Grundläggande vetenskaper , Energi , Strömningsmekanik , Hållbar utveckling , Nanovetenskap och nanoteknik , Transport , Basic Sciences , Energy , Fluid mechanics , Sustainable Development , Nanoscience & Nanotechnology , Transport