Lubricant-Derived Ash Properties and Their Effects on Diesel Particulate Filter Pressure-Drop Performance

2010 ◽  
Vol 133 (3) ◽  
Author(s):  
Alexander Sappok ◽  
Victor W. Wong
Keyword(s):  
Performance Evaluation ◽  
Pressure Drop ◽  
Effective Means ◽  
Engine Performance ◽  
Particulate Filter ◽  
Diesel Particulate ◽  
Particulate Filters ◽  
Loading System ◽  
Filtration Area ◽  
Underlying Mechanisms

Diesel particulate filters (DPFs) have seen widespread use in on- and off-road applications as an effective means for meeting increasingly stringent particle emission regulations. Over time, incombustible material or ash, primarily derived from metallic additives in the engine lubricant, accumulates in the DPF. Ash accumulation leads to increased flow restriction and an associated increase in pressure-drop across the particulate filter, negatively impacting engine performance and fuel economy and eventually requiring periodic filter service or replacement. While the adverse effects of ash accumulation on DPF performance are well known, the underlying mechanisms controlling these effects are not. The results of this work show ash accumulation and distribution in the DPF as a dynamic process with each stage of ash accumulation altering the filter’s pressure-drop response. Through a combined approach employing targeted experiments and comparison with the existing knowledge base, this work further demonstrates the significant effect ash deposits have on DPF pressure-drop sensitivity to soot accumulation. Ash deposits reduce the available filtration area, resulting in locally elevated soot loads and higher exhaust gas velocities through the filter, altering the conditions under which the soot is deposited and ultimately controlling the filter’s pressure-drop characteristics. In this study, a novel accelerated ash loading system was employed to generate the ash and load the DPFs under carefully controlled exhaust conditions. The ash loading system was coupled to the exhaust of a Cummins ISB diesel engine, allowing for accelerated ash loading and DPF performance evaluation with realistic exhaust conditions. Following DPF performance evaluation, the filters were subjected to a detailed post-mortem analysis in which key ash properties were measured and quantified. The experimental results, coupled with the ash property measurements, provide additional insight into the underlying physical mechanisms controlling ash properties, ash/soot interactions, and their effects on DPF performance.

Lubricant-Derived Ash Properties and Their Effects on Diesel Particulate Filter Pressure Drop Performance

2009 ◽  
Author(s):  
Alexander Sappok ◽  
Victor W. Wong
Keyword(s):  
Performance Evaluation ◽  
Pressure Drop ◽  
Effective Means ◽  
Engine Performance ◽  
Particulate Filter ◽  
Diesel Particulate ◽  
Particulate Filters ◽  
Loading System ◽  
Filtration Area ◽  
Underlying Mechanisms

Diesel particulate filters (DPF) have seen widespread use in on- and off-road applications as an effective means for meeting increasingly stringent particle emissions regulations. Over time, incombustible material or ash, primarily derived from metallic additives in the engine lubricant, accumulates in the DPF. Ash accumulation leads to increased flow restriction and an associated increase in pressure drop across the particulate filter, negatively impacting engine performance and fuel economy, and eventually requiring periodic filter service or replacement. While the adverse effects of ash accumulation on DPF performance are well known, the underlying mechanisms controlling these effects are not. The results of this work show ash accumulation and distribution in the DPF as a dynamic process with each stage of ash accumulation altering the filter’s pressure drop response. Through a combined approach employing targeted experiments and comparison with the existing knowledge base, this work further demonstrates the significant effect ash deposits have on DPF pressure drop sensitivity to soot accumulation. Ash deposits reduce the available filtration area, resulting in locally elevated soot loads and higher exhaust gas velocities through the filter, altering the conditions under which the soot is deposited and ultimately control the filter’s pressure drop characteristics. In this study, a novel accelerated ash loading system was employed to generate the ash and load the DPFs under carefully-controlled exhaust conditions. The ash loading system was coupled to the exhaust of a Cummins ISB diesel engine, allowing for accelerated ash loading and DPF performance evaluation with realistic exhaust conditions. Following DPF performance evaluation, the filters were subjected to a detailed post-mortem analysis in which key ash properties were measured and quantified. The experimental results, coupled with the ash property measurements, provide additional insight into the underlying physical mechanisms controlling ash properties, ash/soot interactions, and their effects on DPF performance.

Modeling of Pressure Drop in a 3-D Network Ceramic Diesel Particulate Filter

2011 ◽  
Vol 311-313 ◽  
pp. 1924-1929
Author(s):  
Xu Dong Liu ◽  
Xiao Guo Bi
Keyword(s):  
Pressure Drop ◽  
Effective Means ◽  
Operating Conditions ◽  
Particulate Filter ◽  
Three Dimension ◽  
Promising Alternative ◽  
Diesel Particulate ◽  
Pressure Drops ◽  
Particulate Filters ◽  
Catalytic Coating

Diesel Particulate Filters (DPFs) provide probably the most effective means of trapping the exhaust emitted particulates from diesel engines. Three-dimension network ceramic filters become a promising alternative to the conventional wall flow filters, since they are effective in filtering small sized particles and provide a large specific surface area for catalytic coating. A mathematical model of pressure drop for a three-dimension network ceramic DPFs is developed. The model calculates the pressure drop of a filter as a function of the geometric filtering properties, operating conditions and structure of trapping. The calculated pressure drops of a filter agree well with the experimental results. The pressure drop of DPFs increases linearly with increasing trap length, and there is a nonlinear relationship between the exhaust gas mass flow rate and pressure drop. For optimized traps, the pressure drops are much lower than those of the filters with a unitary trap structure.

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.

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

2020 ◽  
pp. 146808742091667
Author(s):  
Onoufrios Haralampous ◽  
Marios Mastrokalos ◽  
Fotini Tzorbatzoglou ◽  
Chris Dritselis
Keyword(s):  
Steady State ◽  
Pressure Drop ◽  
Filtration Efficiency ◽  
Driving Cycle ◽  
Ceramic Filter ◽  
Particulate Filter ◽  
Local Pressure ◽  
Particulate Filters ◽  
Pressure Loss Coefficient ◽  
Particulate Mass

A model suitable for wall-flow particulate filters with partial rear plug damage is developed and experimentally validated in this work. A ceramic filter with 16% of the rear plugs mechanically removed is tested at steady-state conditions on the engine bench and transient driving cycle conditions on the chassis dynamometer. After decanning of the monolith, destructive analysis is conducted to identify deposit loading variations and scanning electron microscopy is used to study the deposit structures in the channels. It is shown that channels without rear plugs develop distinct deposit structures in the entry zone. Hence, a local pressure loss coefficient is applied to model the effect of entrance flow constrictions, taking also into account deposit restructuring phenomena at higher flow rates. In addition, a deep-bed filtration submodel is used to capture the effect of non-uniform wall velocities on deposit accumulation in the wall. The modified model is first fitted to the engine bench data and then validated in a wider range of conditions using the driving cycle tests. With the exception of prolonged steady-state loading conditions, good pressure drop and filtration efficiency predictions are obtained throughout the tests in conjunction with correct deposit property profiles. Notably, the cold-start worldwide harmonized light vehicles test cycle shows that the current European on-board diagnosis threshold limit for particulate mass is too relaxed to trigger a malfunction indication for moderate filter faults. In conclusion, the model can be applied in damaged particulate filter studies for the assessment of leaked particulate mass, the specification of more effective legislation limits and the development of rigorous on-board diagnosis systems and algorithms.

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.

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.

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 Fault Diagnosis of the Blocking Diesel Particulate Filter Based on Spectral Analysis

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 943 ◽  
Author(s):  
Shuang-xi Liu ◽  
Ming Lü
Keyword(s):  
Spectral Analysis ◽  
Fault Diagnosis ◽  
Diesel Engine ◽  
Characteristic Frequency ◽  
Diesel Particulate Filter ◽  
Engine Performance ◽  
Characteristic Parameter ◽  
Particulate Filter ◽  
Diesel Particulate ◽  
Treatment Techniques

Diesel particulate filter is one of the most effective after-treatment techniques to reduce Particulate Matters (PM) emissions from a diesel engine, but the blocking Diesel Particulate Filter (DPF) will seriously affect the engine performance, so it is necessary to study the fault diagnosis of blocking DPF. In this paper, a simulation model of an R425DOHC diesel engine with wall-flow ceramic DPF was established, and then the model was verified with experimental data. On this basis, the fault diagnosis of the blocking DPF was studied by using spectral analysis on instantaneous exhaust pressure. The results showed that both the pre-DPF mean exhaust pressure and the characteristic frequency amplitude of instantaneous exhaust pressure can be used as characteristic parameters of monitoring the blockage fault of DPF, but it is difficult to monitor DPF blockage directly by instantaneous exhaust pressure. In terms of sensitivity, the characteristic frequency amplitude of instantaneous exhaust pressure is more suitable as a characteristic parameter to monitor DPF blockage than mean exhaust pressure. This work can lay an important theoretical foundation for the on-board diagnosis of DPF.

Sign in / Sign up

Export Citation Format

Share Document