Modeling of Diesel Particulate Filter Regeneration under the Urban Dynamometer Driving Schedule

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Di Huang ◽  
Jason M. Keith
Keyword(s):  
State Standards ◽  
Particulate Filter ◽  
Transient Temperature ◽  
Dimensional Model ◽  
Thermal Regeneration ◽  
Diesel Particulate ◽  
One Dimensional ◽  
Deposit Thickness ◽  
Particulate Filters ◽  
Exhaust Temperature

Abstract Particulate Matter (PM) emissions from either on-road or off-road diesel engines are subject to federal and/or state standards. Recently, Diesel Particulate Filters (DPF) have been shown to be the most efficient way to reduce the PM emissions. However, DPFs need to be regenerated periodically. In order to predict when to regenerate the DPF under real-time driving conditions, a regeneration model for the DPF is needed. In this study, a transient one-dimensional model is used to track gas and solid temperatures and the particulate deposit thickness, and is studied under the Urban Dynamometer Driving Schedule (UDDS) which has variable exhaust flow rate, exhaust temperature, and PM concentration. In order to determine the best conditions, the thermal regeneration is initiated at different time points during the UDDS cycle. Moreover, we also calculate the transient temperature profile and the deposit thickness for each case. We found that the regeneration efficiency is the highest when the regeneration is initiated at 180 seconds into the UDDS cycle which corresponds to a period of extended city driving without stopping.

scholarly journals Late Fuel Post-Injection Influence on the Dynamics and Efficiency of Wall-Flow Particulate Filters Regeneration

2019 ◽  
Vol 9 (24) ◽  
pp. 5384 ◽  
Author(s):  
José Ramón Serrano ◽  
Pedro Piqueras ◽  
Joaquín de la Morena ◽  
Enrique José Sanchis
Keyword(s):  
Fuel Consumption ◽  
Particulate Filter ◽  
Exhaust Gas ◽  
Post Injection ◽  
Gas Temperature ◽  
Diesel Particulate ◽  
Particulate Filters ◽  
Exhaust Temperature ◽  
Injection Parameters ◽  
Wall Flow

Late fuel post-injections are the most usual strategy to reach high exhaust temperature for the active regeneration of diesel particulate filters. However, it is important to optimise these strategies in order to mitigate their negative effect on the engine fuel consumption. This work aims at understanding the influence of the post-injection parameters, such as its start of injection and its fuel quantity, on the duration of the regeneration event and the fuel consumption along it. For this purpose, a set of computational models are employed to figure out in a holistic way the involved phenomena in the interaction between the engine and the exhaust gas aftertreatment system. Firstly, an engine model is implemented to evaluate the effect of the late fuel post-injection pattern on the gas properties at the exhaust aftertreatment system inlet in different steady-state operating conditions. These are selected to provide representative boundary conditions of the exhaust gas flow concerning dwell time, exhaust temperature and O 2 concentration. In this way, the results are later applied to the analysis of the diesel oxidation catalyst and wall-flow particulate filter responses. The dependence of the diesel particulate filter (DPF) inlet temperature is discussed based on the efficiency of each post-injection strategy to increase the exhaust gas temperature. Next, the influence on the dynamics of the regeneration of the post-injection parameters through the change in gas temperature and O 2 concentration is finally studied distinguishing the pre-heating, maximum reactivity and late soot oxidation stages as well as the required fuel consumption to complete the regeneration process.

A control-oriented modular one-dimensional model for wall-flow diesel particulate filters

2017 ◽  
Vol 19 (3) ◽  
pp. 329-346 ◽  
Author(s):  
Soroosh Hassanpour ◽  
John McPhee
Keyword(s):  
Differential Equations ◽  
Dimensional Model ◽  
Orthogonal Collocation ◽  
Diesel Particulate ◽  
One Dimensional ◽  
Diesel Particulate Filters ◽  
Particulate Filters ◽  
Wall Flow ◽  
Flow Pressure ◽  
Regeneration Processes

A comprehensive modular one-dimensional physics-based mathematical model is developed for non-isothermal compressible flow, pressure drop, and filtration and regeneration processes in wall-flow diesel particulate filters. Employing a modified orthogonal collocation method and symbolic computation in Maple™, the governing partial differential equations are reduced to a control-oriented model governed by ordinary differential equations which can be solved in real time. Numerical examples are provided to indicate the accuracy and computational efficiency of the developed model and to study the different behaviors of wall-flow diesel particulate filters.

Simulating Area Conservation and the Gas-Wall Interface for One-Dimensional Based Diesel Particulate Filter Models

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Christopher Depcik ◽  
Dennis Assanis
Keyword(s):  
Classical Model ◽  
Particulate Filter ◽  
Gas Temperature ◽  
Flow Area ◽  
Diesel Particulate ◽  
One Dimensional ◽  
Flow Equations ◽  
Particulate Filters ◽  
Soot Loading ◽  
Physical Phenomena

Researchers have been using one-dimensional based models of diesel particulate filters (DPFs) for over two decades with good success in comparison to measured experimental data. Recent efforts in literature have expanded the classical model to account for the effects of varying soot layer thickness on the flow area of the gases. However, some discrepancies exist with respect to this formulation and the physical phenomena modeled in the channel equations. In addition, there is still some discussion regarding the calculation of the gas temperature within the soot and wall layers. As a result, this paper presents a model to discuss these different phenomena to remove or validate previous assumptions. In specific, formulation of the flow equations in area-conserved format (or quasi-one-dimensional) allows the model to account for the changes in the gaseous area as a function of soot loading. In addition, imposing thermodynamic equilibrium at the interface of the channels and wall layers allows the model to capture the thermal entrance lengths. These tasks were undertaken to illustrate whether or not the results justify the effort is worthwhile and this additional complexity needs to be incorporated within the model. By utilizing linear density interpolation in the wall to increase the computational efficiency of the code, it was determined that the classical model assumptions of neglecting soot thickness and gas temperature in the wall are valid within the range of typical DPF applications.

A Numerical Study on Uncontrolled Regeneration Processes in Diesel Particulate Filters

2004 ◽  
Author(s):  
Dong Wang ◽  
Meiping Wang ◽  
Graham T. Reader ◽  
Ming Zheng
Keyword(s):  
Numerical Study ◽  
Soot Oxidation ◽  
Thermal Runaway ◽  
Particulate Filter ◽  
Thermal Regeneration ◽  
Transient Model ◽  
Diesel Particulate ◽  
Exhaust Temperature ◽  
Major Factors ◽  
Regeneration Processes

An effective regeneration is needed to remove the accumulated soot in a Diesel Particulate Filter (DPF). However, the sudden heat release by soot oxidation during an uncontrolled thermal regeneration process may cause the substrate of a DPF to overheat. The consequent thermal stress could even result in structural failure. In this paper, a cone-dimensional transient model was employed to describe the exhaust flow, heat transfer, and chemical reaction processes within the DPF substrate during regeneration. The model was validated preliminarily against the experimental data of previous researchers. By using this mode, a variety of uncontrolled regeneration processes were simulated to analyze the different mechanisms of DPF overheating. The results show that the exhaust temperature, oxygen concentration, and PM loading are three major factors that effect DPF overheating. Furthermore, the tendency of uncontrolled thermal runaway could be reduced by changing either the thermal runaway could be reduced by changing either the thermal properties or the structure of the DPF substrate.

Comparison of intake and exhaust throttling for diesel particulate filter active regeneration of non-road diesel engine with mechanical fuel injection pump

2020 ◽  
pp. 146808742092603
Author(s):  
Wonmo Kang ◽  
Sukang Pyo ◽  
Hongsuk Kim
Keyword(s):  
Fuel Consumption ◽  
Diesel Particulate Filter ◽  
Fuel Injection ◽  
Particulate Filter ◽  
Diesel Particulate ◽  
Air Mass ◽  
Filter Regeneration ◽  
Exhaust Temperature ◽  
Injection Pump ◽  
Fuel Injection Pump

Diesel particulate filter regeneration using intake and exhaust throttling is technically simple and economically efficient compared to other methods. The purpose of this study is to investigate not only the reasons for the increase in exhaust temperature during intake or exhaust throttling but also their feasibility as a diesel particulate filter regeneration technology. In this study, a non-road diesel engine having a mechanical fuel injection pump was used for experiments. The changes in exhaust temperatures were measured during intake and exhaust throttling for the no-load maximum revolutions per minute engine condition. The experimental results exhibited that both intake and exhaust throttling reduced the intake air mass flow rate and increased piston pumping, which then increased fuel consumption. These effects were the primary reasons for increasing the temperature of exhaust gases. In particular, intake throttling was more effective than exhaust throttling in terms of reducing the intake air mass flow rate. However, exhaust throttling caused larger pumping losses, resulting in higher fuel consumption. Furthermore, in case of exhaust throttling, engine combustion was possible even at high equivalence ratios because of the larger amounts of residual gases in the combustion chamber. In summary, exhaust throttling is more effective for regenerating a diesel particulate filter at a high temperature than intake throttling. In addition, this study verified the feasibility of diesel particulate filter regeneration using exhaust throttling through analyses of diesel particulate filter regeneration efficiency, fuel consumption, and exhaust concentration when regenerating the diesel particulate filter by increasing the exhaust temperature through exhaust throttling.

Experimental study of lubricant-derived ash effects on diesel particulate filter performance

2019 ◽  
pp. 146808741987457 ◽  
Author(s):  
Jun Zhang ◽  
Yanfei Li ◽  
Victor W Wong ◽  
Shijin Shuai ◽  
Jinzhu Qi ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Diesel Particulate Filter ◽  
Particulate Filter ◽  
Maximum Temperature ◽  
Particle Emissions ◽  
Diesel Particulate ◽  
Particulate Filters ◽  
Filter Performance ◽  
Soot Loading ◽  
Active Regeneration

Diesel particulate filters are indispensable for diesel engines to meet the increasingly stringent emission regulations. A large amount of ash would accumulate in the diesel particulate filter over time, which would significantly affect the diesel particulate filter performance. In this work, the lubricant-derived ash effects on diesel particulate filter pressure drop, diesel particulate filter filtration performance, diesel particulate filter temperature field during active regeneration, and diesel particulate filter downstream emissions during active regeneration were studied on an engine test bench. The test results show that the ash accumulated in the diesel particulate filter would decrease the diesel particulate filter pressure drop due to the “membrane effect” when the diesel particulate filter ash loading is lower than about 10 g/L, beyond which the diesel particulate filter pressure drop would be increased due to the reduction of diesel particulate filter effective volume. The ash loaded in the diesel particulate filter could significantly improve the diesel particulate filter filtration efficiency because it would fill the pores of diesel particulate filter wall. The diesel particulate filter peak temperature during active regeneration is consistent with the diesel particulate filter initial actual soot loading density prior to regeneration at various diesel particulate filter ash loading levels, while the diesel particulate filter maximum temperature gradient would increase with the diesel particulate filter ash loading increase, whether the diesel particulate filter is regenerated at the same soot loading level or the same diesel particulate filter pressure drop level. The ash accumulation in the diesel particulate filter shows little effects on diesel particulate filter downstream CO, total hydrocarbons, N2O emissions, and NO2/NO x ratio during active regeneration. However, a small amount of SO2 emissions was observed when the diesel particulate filter ash loading is higher than 10 g/L. The ash accumulated in the diesel particulate filter would increase the diesel particulate filter downstream sub-23 nm particle emissions but decrease larger particle emissions during active regeneration.

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

2019 ◽  
Vol 22 (1) ◽  
pp. 50-63
Author(s):  
Christian Zöllner ◽  
Onoufrios Haralampous ◽  
Dieter Brüggemann
Keyword(s):  
Flow Rate ◽  
Large Particle ◽  
Operating Conditions ◽  
Particulate Filter ◽  
Diesel Particulate ◽  
Agglomerate Size ◽  
Diesel Particulate Filters ◽  
Particulate Filters ◽  
Operating Points ◽  
Particle Agglomerate

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.

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