Effect analysis on pressure drop of the continuous regeneration-diesel particulate filter based on NO 2 assisted regeneration
111
Citation
35
Reference
10
Related Paper
Citation Trend
Keywords:
Back pressure
Diesel particulate filter (DPF) is widely used to trap fine soot particles emitted from diesel engines. It can collect particles as small as submicron but it is necessary to oxidize accumulated particles by heating the filter. Temperatures of 600 degree C or higher is required to oxidize the soot but it is difficult to maintain stable reaction because this is exoergic reaction. The filter is sometimes damaged due to thermal runaway of the reaction. To address this trade-off problem, we have studied low temperature regeneration of DPF using sliding discharge, which can be generated on the surface of DPF and produces oxidative species at room temperature. Diesel soot collected by DPF was used. Simulated air consisting of N2 and O2 and not including CO2 or CO was used and CO and CO2 concentration was monitored by real time FTIR to estimate the soot oxidation. All the experiment was carried out at temperatures between 100 and 190 degree C to simulate exhaust temperature under low load. Experimental results show that soot was oxidized by generating sliding discharge on the DPF. No thermal damage of the DPF was found. Energy efficiency, denoted by the amount of oxidized soot per electric energy dissipated in the sliding discharge, increased with increasing the temperature as well as oxygen concentration in the test gas. Small amount of Ag2O supported by the DPF significantly increase the energy efficiency of soot oxidation. On the contrary, excessive amount of Ag2O resulted in energy efficiency lower than that of DPF without Ag2O probably because the sliding discharge was not generated favorably due to high conductivity resulted from metal Ag. These results suggest that sliding discharge can induce soot oxidation and that Ag2O possibly catalyzes soot oxidation.
Cite
Citations (2)
Carbon fibers
Mass concentration (chemistry)
Cite
Citations (11)
This paper presents a control-oriented model describing the dynamics of oxygen concentration through a Diesel engine aftertreatment system that includes a Diesel oxidation catalyst (DOC) and a Diesel particulate filter (DPF). Exhaust gas oxygen concentration is important for catalysts such as NOx conversion efficiencies of selective catalytic reduction (SCR) systems and lean NOx traps (LNT). In the presence of low-pressure loop exhaust gas recirculation (EGR), the exhaust gas oxygen concentration after-DPF also influences combustion. Due to the chemical reactions occurring inside DOC and DPF, the exhaust gas oxygen concentration considerably varies through the aftertreatment systems. Directly measuring the exhaust gas oxygen concentrations at different locations through the exhaust gas aftertreatment system is costly and unreliable. A dynamic model is thus needed in order to design model-based observers to estimate the exhaust gas oxygen concentrations at various locations. The oxygen-related reactions within a DOC and a DPF are investigated in this study. A lumped-parameter, control-oriented DOC-DPF oxygen concentration dynamic model was developed by a multi-objective optimization method and validated with experimental data obtained on a medium-duty Diesel engine equipped with full aftertreatment systems. Experimental results show that the model can well capture the oxygen dynamics across the Diesel engine aftertreatment systems.
Limiting oxygen concentration
Diesel exhaust fluid
Oxygen sensor
Cite
Citations (2)
Cite
Citations (27)
Deposition
Cite
Citations (54)
Filtration (mathematics)
Deposition
Cite
Citations (74)
Diesel Particulate Filter (DPF) is one of the prominent after-treatment devices invented to reduce particulate matter (PM) emission from diesel engines. With the latest emission standard becoming more stringent in order to maintain the environment sustainability, the study on soot filtration phenomenon occurring inside the DPF is crucial. In addition, the advancement of computer technology contributes to better understanding by simulating the soot filtration process. The flow pattern and velocity of exhaust gas are analyzed in order to examine the flow path and thus the area for soot deposition inside the channel. After a certain soot deposition time, a pressure drop is created and different patterns are observed during initial stage, soot loading and regeneration steps. The soot cake formation also affects the efficiency and pressure drop of the DPF. Hence, these understanding can be adopted for advanced research in optimizing the DPF design and efficiency.
Filtration (mathematics)
Deposition
Cite
Citations (43)
A major concern in operating a diesel engine is how to reduce the soot emission from the exhaust gases, as soot has a negative effect on both human health and the environment. More stringent emission regulations make the diesel particulate filter (DPF) an indispensable after-treatment component to reduce diesel soot from exhaust gases. The most important issue in developing an effective DPF, however, is regeneration technology to oxidize the diesel soot trapped in the filter, either periodically or continuously, during regular engine operations. Various methods exist for regenerating diesel soot captured by the filter. Of these, NO2 is widely used for continuous regeneration of diesel soot since it can oxidize diesel soot at lower temperatures than the conventional oxidizer O2 In this work, after introducing governing equations for trapping and regenerating diesel soot in the DPF, regeneration behavior is examined by changing such various parameters as exhaust gas temperature and O2 concentration. Numerical investigation is then performed in order to find the optimum NO2/soot ratio required for continuous regeneration of the soot deposited in the DPF.
Cite
Citations (21)
Reactivity
Cite
Citations (2)
Abstract A new reactor designed to test soot combustion on a filter coated with an oxidation catalyst is described. It is designed to achieve screening investigations of catalysts in realistic conditions, i.e., close to those prevailing in a diesel particulate filter (DPF). In a DPF a soot layer is formed at the surface of a porous wall (filtration area) which may or may not be covered with a catalytic layer. In this new setup, the soot is deposited on a sample of a DPF which can be easily impregnated with oxidation catalysts. A model soot (commercial carbon black) is used for the investigation, and different procedures for the soot „deposit on the filter are tested.
Filtration (mathematics)
Carbon fibers
Cite
Citations (2)