Browse Topic: Diesel exhaust emissions

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QA Test for CSP-7037053020245/15/2024
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Airlines Electronic Engineering Committee
Exploring the Benefits of Karanja-Oil-Derived Biodiesel-Water Emulsion as a Potential Fuel for Diesel Engines Operated with High-Pressure Fuel Injection Systems03-17-01-00037/21/2023
Abstract Biodiesel is a suitable alternative to diesel because of its carbon neutrality, renewability, lubricity, and lower pollutant emissions. However, extensive research indicates higher oxides of nitrogen (NOx) emissions with biodiesel. A practical method to combat this problem is utilizing water and biodiesel as emulsions. The effect of biodiesel-water emulsion in high-pressure fuel injection systems is not fully explored in the existing literature. The present study addresses this research gap by utilizing biodiesel-water emulsions in a modified light-duty diesel engine. The governor-controlled injection system was adapted to a fully flexible electronic system capable of high-pressure injection. Unlike other literature studies, the fuel injection timings were optimized with biodiesel-water emulsions to maximize brake thermal efficiency (bte) at every load condition. In a novel attempt, the biodiesel source, i.e., raw Karanja oil (RKO), a triglyceride, was utilized as the surfactant to stabilize the biodiesel-water emulsions containing 6%, 12%, and 18% water. The emulsions reduced the ignition delay and cylinder pressures, with less-intense premixed combustion and a more significant diffusion phase combustion than biodiesel. The emulsions also present a delayed combustion phasing following the injection timing trends. Among the tested emulsions, at 5.08 bar brake mean effective pressure (BMEP), 18% biodiesel-water emulsion resulted in an 18% reduced brake specific fuel consumption (bsfc), 5% increase in bte, 30% and 7% mitigation in NOx and smoke levels, with an increase of 10% and 28% for unburned hydrocarbon (HC) and carbon monoxide (CO) emissions.
Gowrishankar, Sudarshan, Krishnasamy, Anand, Aidhen, Indrapal Singh
Impact of Non-Thermal Plasma on Particulate Emissions in Application in a Diesel Engine Exhaust DuctSAE-PP-001611/26/2021
Particulates and nitrogen oxides comprise the main emission components of the Diesel combustion and therefore are subject to exhaust emission legislation in respective applications. Yet, with ever more stringent emission standards and test-procedures, such as in passenger vehicle applications, resulting exhaust gas after-treatment systems are quite complex and costly. Hence, new technologies for emission control have to be explored. The application of non-thermal plasma (NTP) as a means to perform exhaust gas after-treatment is one such promising technology. In several publications dealing with NTP exhaust gas after-treatment the plasma state was generated via dielectric barrier discharges. Another way to generate a NTP is by a corona high-frequency discharge. Hence, in contrast to earlier publications, the experiments in this publication were conducted on an operated series-production Diesel engine with an industrial pilottype corona ignition system. Originally developed as an alternative for a spark-plug system in SI engines its attributed properties, such as large penetrated volume and high radical concentration, may also be utilized in the exhaust gas stream. To investigate the effects of a corona discharge on Diesel engine emissions, four igniters were integrated in the exhaust duct of a common-rail direct-injection 2.0 liter diesel engine equipped with a diesel particulate filter (DPF). The impact on particulate number, size distribution as well as on nitrogen oxides has been studied for various operational parameters of the corona system. The particulate number was measured downstream of the DPF to observe the level of improvement for remaining unfiltered nanoparticulates. In this first series of tests, a reduction in particulate number of up to 10 % was achieved depending on engine load. Particulate size distribution was then measured upstream of the DPF. In this case, the highest reduction of 10 % was observed in the midrange particulate size of about 60 nm. No increase in other particulate size ranges has been observed.
MobrxivNonAdmin, Lindsay
Impact of Non-Thermal Plasma on Particulate Emissions in Application in a Diesel Engine Exhaust DuctSAE-PP-001561/25/2021
Particulates and nitrogen oxides comprise the main emission components of the Diesel combustion and therefore are subject to exhaust emission legislation in respective applications. Yet, with ever more stringent emission standards and test-procedures, such as in passenger vehicle applications, resulting exhaust gas after-treatment systems are quite complex and costly. Hence, new technologies for emission control have to be explored. The application of non-thermal plasma (NTP) as a means to perform exhaust gas after-treatment is one such promising technology. In several publications dealing with NTP exhaust gas after-treatment the plasma state was generated via dielectric barrier discharges. Another way to generate a NTP is by a corona high-frequency discharge. Hence, in contrast to earlier publications, the experiments in this publication were conducted on an operated series-production Diesel engine with an industrial pilottype corona ignition system. Originally developed as an alternative for a spark-plug system in SI engines its attributed properties, such as large penetrated volume and high radical concentration, may also be utilized in the exhaust gas stream. To investigate the effects of a corona discharge on Diesel engine emissions, four igniters were integrated in the exhaust duct of a common-rail direct-injection 2.0 liter diesel engine equipped with a diesel particulate filter (DPF). The impact on particulate number, size distribution as well as on nitrogen oxides has been studied for various operational parameters of the corona system. The particulate number was measured downstream of the DPF to observe the level of improvement for remaining unfiltered nanoparticulates. In this first series of tests, a reduction in particulate number of up to 10 % was achieved depending on engine load. Particulate size distribution was then measured upstream of the DPF. In this case, the highest reduction of 10 % was observed in the midrange particulate size of about 60 nm. No increase in other particulate size ranges has been observed.
MobrxivNonAdmin, Lindsay
011 - State-of-Health Online Estimation for Li-Ion BatterySAE-PP-001231/21/2021
To realize a fast and high-precision online state-of-health (SOH) estimation of lithium-ion (Li-Ion) battery, this article proposes a novel SOH estimation method. This method consists of a new SOH model and parameters identification method based on an improved genetic algorithm (Improved-GA). The new SOH model combines the equivalent circuit model (ECM) and the data-driven model. The advantages lie in keeping the physical meaning of the ECM while improving its dynamic characteristics and accuracy. The improved-GA can effectively avoid falling into a local optimal problem and improve the convergence speed and search accuracy. So the advantages of the SOH estimation method proposed in this article are that it only relies on battery management systems (BMS) monitoring data and removes many assumptions in some other traditional ECM-based SOH estimation methods, so it is closer to the actual needs for electric vehicle (EV). By comparing with the traditional ECM-based SOH estimation method, the algorithm proposed in this article has higher accuracy, fewer identification parameters, and lower computational complexity.
MobrxivNonAdmin, Lindsay
Single vs Double Stage Partial Flow Dilution System: Automobile PM Emission Measurement2020-01-03664/14/2020
The US Code of Federal Regulations (CFR) Title 40 Part 1065 and 1066 require gravimetric determination of automobile Particulate Matter (PM) collected onto filter media from the diluted exhaust. PM is traditionally collected under simulated driving conditions in a laboratory from a full flow Constant Volume Sampler (CVS) system, where the total engine exhaust is diluted by HEPA filtered air. This conventional sampling and measurement practice is facing challenges in accurately quantifying PM at the upcoming 2025-2028 CARB LEVIII 1 mg/mi PM emissions standards. On the other hand, sampling a large amount of PM emitted from large size high power engines introduces additional challenges. Applying flow weighting, adjusting the Dilution Ratio (DR) and Filter Face Velocity (FFV) are proposed options to overcome these challenges. The Partial Flow Dilution System (PFDS) technique has been recognized as a viable alternative to the CVS method, to meet the wide range DR and FFV requirements for PM determination from both Light-Duty Vehicles (LDV) and Heavy-Duty Engines (HDE) [4, 5, 6, 7, 8]. In this study, performance of a PFDS for PM measurement with Single Dilution (SD) and Double Dilution (DD) configurations against conventional CVS sampling was investigated. Tests were run on a Cummins heavy-duty 8.9L engine with maximum rated power of 380 HP in an engine test cell. The engine aftertreatment system is comprised of a combined Diesel Oxidation Catalyst (DOC) and Selective Catalyst Reduction (SCR). The reference data, also referred to as historical data, was generated in a test cell using the CVS method. PM measurements were made over the US Non-road Transient Cycle (NRTC) and Ramped Modal Cycle (RMC). The brake-specific particulate matter (BSPM) was calculated using the raw chemical balance utilizing intake airflow measurements and the measurement of gases in the exhaust. The PFDS with single and double tunnel configuration showed good repeatability with a COV of <6% when compared against the historical data which has a COV of <8%. The PFDS with single and double dilution met all the global regulatory requirements with the correlation coefficient of 1.005 and the coefficient of determination (R2) greater than 0.98.
Rahman, Montajir, Rooney, Rick, Nevius, Tim, Otsuki, Yoshinori, Yoshida, Taisuke, Khan, Yusuf, Liew, Chet Mun, Basrur, Chirag
Impact of Post-Injection Parameters on Soot and Hydrocarbon Emissions in a Common-Rail Heavy-Duty Diesel Engine2020-01-03744/14/2020
In this paper, based on a direct injection (DI) diesel engine, soot and exhaust gaseous emissions were measured by a smoke meter and multi-component gas analyzer based on Fourier Transform Infrared (FTIR) spectroscopy under post-injection condition. The post-injection timing changed from 20 crank angle degree (CAD) after top dead center (ATDC) to 120 CAD ATDC, and the post-injection mass was set to either 5mg, 10mg or 15mg, to find a suitable post-injection strategy in a wide assessment range based on diesel oxidation catalyst (DOC) coupled diesel particle filter (DPF) after-treatment technology demands, considering emission reduction and after-treatment gas atmosphere investigation. The results showed that post-injection could achieve NOx emission reduction, up to 14%. Besides, post-injection led to worsening soot emissions, and more hydrocarbon (HC) emissions were detected compared to the condition without the post-injection. With the post-injection, a higher concentration of unsaturated HC emissions (such as C2H2, C2H4, and C3H6), formaldehyde (HCHO), and acetaldehyde (CH3CHO) appeared at late post-injection (after 70°CA). In the measured species, at 80°CA post-injection timing and with 10mg post-injection mass, species with low emissions (<30ppm), included CH4, C2H2, C3H6, and CH3CHO; species with medium emissions (>30ppm and <100ppm), included NO2, HCHO, C2H4, and NC8; species with large emissions (>100ppm), included NO, NOx and non-methane hydrocarbon (NMHC). Furthermore, the peak position of NMHC was the same as C3~C8 HCs and different from C2 HCs within the scope of the experiment, which indicated that, in terms of concentration, the proportion of C2 HCs was not dominant in total NMHC emissions.
Pan, Wang, Wu, Yan, Jing, Yi, Zizeng, Huang
Impact of Multiple Injection Strategies on Performance and Emissions of Methanol PPC under Low Load Operation2020-01-05564/14/2020
There is growing global interest in using renewable alcohols to reduce the greenhouse gases and the reliance on conventional fossil fuels. Recent studies show that methanol combined with partially premixed combustion provide clear performance and emission benefits compared to conventional diesel diffusion combustion. Nonetheless, high unburned hydrocarbon (HC) and carbon monoxide (CO) emissions can be stated as the main PPC drawback in light load condition when using high octane fuel such as Methanol with single injection strategy. Thus, the present experimental study has been carried out to investigate the influence of multiple injection strategies on the performance and emissions with methanol fuel in partially premixed combustion. Specifically, the main objective is to reduce HC, CO and simultaneously increase the gross indicated efficiency compared to single injection strategy. The work was performed with a single cylinder heavy duty engine, operated at 4 bar gross indicated mean effective pressure, and an engine speed of 1200 rpm. Double and triple injections were implemented with varying dwells, injection timings and fuel mass proportions. The experimental results were analyzed with a merit function to select the optimal injection strategy. Concerning emissions, the constraints for the merit function were based on the EURO VI limits, while the highest gross indicated efficiency for single injection was used to define the performance constraint. The results revealed that with proper dwell and mass proportion, multiple injection strategies can improve the gross indicated efficiency and reduce the emissions compare to single injection strategy.
Aziz, Amir, Garcia, Antonio, Pinto Dos Santos, Clarisse, Tuner, Martin
Nonlinear Identification Modeling for PCCI Engine Emissions Prediction Using Unsupervised Learning and Neural Networks2020-01-05584/14/2020
Premixed charged compression ignition (PCCI) is an advanced combustion strategy, which has the potential to achieve ultra-low nitrogen oxide and soot emissions at high thermal efficiencies. PCCI combustion is characterized by a complex nonlinear chemical-physical process, which indicates that a physical description involves significant development times and also high computation cost. This paper presents a method to use cylinder pressure data and engine operations parameters for prediction of PCCI engine emissions by unsupervised learning and nonlinear identification techniques. The proposed method first uses principal component analysis (PCA) to reduce the dimension of the cylinder-pressure data. Based on the PCA analysis, a multi-input multi-out model was developed for nitrogen oxide and soot emission prediction by multi-layer perceptron (MLP) neural network. Before the training process, a second principal component analysis was done to reduce the input dimension with hyper-parameters thereby reducing memory requirements of the models. The algorithm is applied to an experimental data set from a single-cylinder light-duty engine with piezo injection system. By comparing the model predictions with experimental results, it is shown that the neural network coupling with the unsupervised learning method can successfully capture the nonlinear relationship between the state parameters and the emissions of PCCI combustion system.
Pan, Wang, Korkmaz, Metin, Beeckmann, Joachim, Pitsch, Heinz
Dimensional Optimization of Key Parameters Using DoE Technique to Achieve Better NO X Emission Values in Mass Production of Single Cylinder Small Diesel Engines for 3 Wheeler Applications2020-01-13564/14/2020
Oxides of Nitrogen (NOx) emissions are considered as among the most harmful emissions globally having a direct influence on human beings and the environment. This work deals with a strategy to arrive at achieving lower NOx values consistently in mass production of single cylinder automotive diesel engines meeting BS IV Emission standards using the DoE technique for dimensional optimization of critical parameters. Catalytic converters and particulate filters are mostly used as after - treatment devices for compression Ignition (CI) engines for bringing down the limits (Values) of the pollutants from the tail pipes. But the real ingenuity lies in achieving the same effect through optimization of in - cylinder combustion. Optimization of the critical factors like Nozzle Tip Protrusion (NTP), Static Injection Timing (SIT), Bumping Clearance (BC) and Swirl Number (SN) are considered as the most important engine design parameters for ensuring the optimum combustion which help release of minimal harmful pollutants. In this work, a standard L9 Orthogonal Array (OA) table was used in designing experiments for a study of the interactive model between the said factors and their levels to achieve consistently lower NOx emission values. The design specification of NTP considering the tolerance limit was set between 3.0 mm to 3.30 mm and similarly SIT, BC and Swirl value were set between 0.19 mm to 0.27mm, 0.65mm to 0.75 mm and 2700 rpm to 2800 rpm respectively. Tests were conducted on the basis of standard OA table and the corresponding NOx emissions were measured. It is found that, NTP of 3.2 mm, SIT of 0.19 mm, BC of 0.70 mm and Swirl Rate of 2775 rpm were seen yielding the least NOx emissions. Statistical observations showed the above mentioned combination exhibiting a reduction of NOX achieved with respect to the design specification as 22% and the variation of NOx between engines as 1.1%.
Ramalingam, Jaganathan, B, Prabakaran, Nandagopal, Sasikumar, Venkatesan, Hariram, Mayakrishnan, Jaikumar
A Holistic Approach to Develop a Common Rail Single Cylinder Diesel Engine for Bharat Stage VI Emission Legislation2020-01-13574/14/2020
The upcoming Bharat Stage VI (BS VI) emission legislation has put enormous pressure on the future of small diesel engines which are widely used in the Indian market. The present work investigates the emission reduction potential of a common rail direct injection single cylinder diesel engine by adopting a holistic approach of lowering the compression ratio, boosting the intake air and down-speeding the engine. Experimental investigations were conducted across the entire operating map of a mass-production, light-duty diesel engine to examine the benefits of the proposed approach and the results are quantified for the modified Indian drive cycle (MIDC). By reducing the compression ratio from 18:1 to 14:1, the oxides of nitrogen (NOx) and soot emissions are reduced by 40% and 75% respectively. However, a significant penalty in fuel economy, unburned hydrocarbon (HC) and carbon monoxide (CO) emissions are observed with the reduced compression ratio. Intake air boosting using a mechanically driven supercharger could overcome the penalty in HC and CO emissions. However, the mechanical frictional losses of the supercharger resulted in a further penalty in the fuel economy. The reduced cylinder pressure due to lower compression ratio and the increased air availability due to intake air boosting could be utilized to improve the full-load performance of the engine by 28%. Further, the advantage of improved engine performance was utilized to down-speed the engine by optimizing the transmission gear ratios without compromising the acceleration performance of the vehicle. Overall, with this holistic approach, soot emission could be reduced by a significant margin of 83% whereas the NOx emission is reduced by 5.8%. Moreover, the HC and CO emissions could be reduced by 17.6% and 30.9% respectively. Furthermore, the fuel economy at the vehicle-level could be improved by 5.4% while improving the in-gear acceleration performance by 9%. Thus, the proposed approach is found to be extremely beneficial to develop small, light-duty diesel engines with compliance on future emission regulations. The reasons behind the observed benefits are explained in detail based on the measured in-cylinder pressure and calculated heat release data.
Vellandi, Vikraman, Ramesh, A., Krishnasamy, Anand
The Application of E-Fuel Oxymethylene Ether OME1 in a Virtual Heavy-Duty Diesel Engine for Ultra-Low Emissions2020-01-03494/14/2020
For long haul transport, diesel engine due to its low fuel consumption and low operating costs will remain dominant over a long term. In order to achieve CO2 neutrality, the use of electricity-based, synthetic fuels (e-fuels) provides a solution. Especially the group of oxymethylene ethers (OME) is given much attention because of its soot-free combustion. However, the new fuel properties and the changed combustion characteristics place new demands on engine design. Meanwhile, the use of new fuels also creates new degrees of freedom to operate diesel engines. In this work, the application of dimethoxymethane (OME1) is investigated by means of 1D simulation at three operating points in a truck diesel engine. The subsystems of fuel injection, air path and exhaust gas are sequentially adjusted for the purpose of low emissions, especially for low nitrogen oxides (NOx). Thanks to the inexistent soot-NOx trade-off, NOx can be considerably reduced by high exhaust gas recirculation (EGR) at a nearly stoichiometric operation. In addition, conceivable configurations of exhaust after-treatment system are analyzed. At last, a holistic layout of a future OME-powered engine is proposed.
Yang, Qirui, Grill, Michael, Bargende, Michael
A Time-Saving Methodology for Optimizing a Compression Ignition Engine to Reduce Fuel Consumption through Machine Learning03-13-02-00192/7/2020
Applying a suitable design optimization technique is a crucial task for optimizing compression ignition engines because of the time-consuming process of optimization even with advanced supercomputers. Traditional computational fluid dynamics (CFD) used in conjunction with design of experiment (DOE) methods requires executing the CFD model several times. A response surface is usually fitted to relate the inputs to the outputs, which is often created based on linear regression. This method is not well suited to capture interaction effects between inputs and nonlinearities existing during engine combustion. A combination of genetic algorithm (GA) and CFD tools usually eventuates better optimum results. However, the CFD simulations must be executed sequentially, resulting in extremely high computational times, which makes it impossible to apply an optimization study using a single desktop computer. The current study examines a novel approach, which combines CFD, GA, and a type of machine learning approach, namely artificial neural networks (ANNs), in order to optimize a compression ignition engine to achieve its minimum indicated specific fuel consumption (ISFC). Start of injection (SOI) timing and input pressure were selected as the optimization variables in order to investigate improvement in ISFC without any hardware modifications of the engine. Maximum in-cylinder peak pressure and ringing intensity (pressure rise rate) were chosen as the optimization constraints. Conducting a reliable optimization study with a single desktop computer in a shorter time can be achieved by using the proposed methodology. The results indicate that a 97% decrease in the estimated number of days to achieve the final results was obtained, compared to the traditional CFD-GA approach. Furthermore, adopting this methodology eliminates the necessity for additional response surface fitting to GA data. Therefore, it facilitates an examination of design parameter effects on the engine outputs, doing sensitivity analysis, post-processing the optimization results, and providing a powerful tool to gain optimum designs. The final optimum point illustrates a 10% improvement in ISFC, while avoiding sensitive regions and without exceeding optimization constraints.
Rahnama, Pourya, Arab, Majid, Reitz, Rolf D.
The Combustion Characteristic of Fuel Additives with Diesel–Ethanol Fuel blends on Engine Performance2019-32-06111/24/2020
Reducing carbon dioxide (greenhouse gas) is one of the most important drivers to promote biofuels. Fuel from biomass has the potential to reduce greenhouse gas emissions and can gradually reduce the dependence on fossil fuels. However, fuel properties can differ significantly from standard diesel fuel and this will affect exhaust emissions and environmental pollution. Diesel – ethanol fuel blends development and specification are currently driven by the engine technology, existing fossil fuel specification and availability of feedstock. Thus, the aims of this study to investigate the effects of fuel additives with diesel–ethanol fuel blend under steady-state conditions. In the present study, the additives were palm diesel, n-butanol, ethyl acetate and di-tert-butyl peroxide (DTBP). The ratio of conventional diesel fuel to ethanol fuel to fuel additive are 80:15:5 by volume of fuel blends. The comparative studies on the effects of fuel additives in the engine performance and phase separation in diesel–ethanol blends. The effects of engine performance included exhaust gas emissions with different fuel additives on small diesel engine are also investigated under different engine conditions in order to considering the engine speed and engine load comparison with conventional diesel. The study found that all the additives are enhanced the stabilities in diesel–ethanol fuel blends and phase separation has not be found under the room temperature. The diesel–ethanol fuel blend with DTBP can improved the highest thermal efficiency with lower exhaust gas emission (e.g. carbon-monoxide, oxides of nitrogen, and soot) compare with conventional diesel with another fuel additives. However, the break specific fuel consumption is higher (>4%) than conventional diesel which could be acceptable range. The results suggest that significant benefits can derive from the use of di-tert-butyl peroxide as fuel additive for diesel and ethanol fuel blends as the alternative fuel for compression ignition engine in terms of engine performance, exhaust gas emissions, after treatment system performance and environmental pollution in the near future.
Theinnoi, Kampanart, Sawatmongkhon, Boonlue, Wongchang, Thawatchai, Sukjit, Ekarong, Chuepeng, Sathaporn
Reduction of a diesel engine NO emissions using the exhaust gas recirculation technique2019-36-00671/13/2020
This paper analyses the effects of the application of the exhaust gas recirculation (EGR) technique in a stationary, single cylinder engine aiming to reduce the emissions of nitrogen oxides (NOx). The engine was operated with diesel oil containing 8% biodiesel (B8) for different load and EGR rates. The engine emissions of carbon monoxide (CO), carbon dioxide (CO2) and nitric oxide (NO) operating without the EGR system were compared with the operation with EGR rates of 15% and 25%. The results revealed that the increase in the EGR rate increased the exhaust gas temperature, the engine specific fuel consumption and the CO and CO2 emissions, but with reduction of up to 72% of NO emissions, when using 25% of EGR rate.
de Oliveira, Alex, Bernardes, Alexandre Pinheiro, Ferreira, Flávio
Arc generated Soot for a Comparison with Practical Diesel Soots using Characterization Analyses with a Time-lapse Regeneration Study on a DPF2019-01-228912/19/2019
This research aims to characterize an arc generated soot that was utilized as a surrogate for diesel engine generated soot. The two laboratory generated soots used in this study are arc generated soot and diesel fuel-lamp flame soot. In order to benchmark these surrogates with diesel engine soot, characterization was done by analyzing their oxidation behaviors, organic elemental composition, and nascent nanostructures. After that, the arc generated soot was utilized in a time-lapse DPF regeneration experiment to investigate its partial oxidation phenomenon using FE-SEM as a visualization tool. As a result, it was found that, by the appearance, arc-soot can be used as a diesel engine soot surrogate to study the shrinkage phenomenon of soot on a DPF substrate.
Srilomsak, Mek, Inaba, Masanobu, Hanamura, Katsunori
Regulated Emissions and Detailed Particle Characterisation for Diesel and RME Biodiesel Fuel Combustion with Varying EGR in a Heavy-Duty Engine2019-01-229112/19/2019
This study investigates particulate matter (PM) and regulated emissions from renewable rapeseed oil methyl ester (RME) biodiesel in pure and blended forms and contrasts that to conventional diesel fuel. Environmental and health concerns are the major motivation for combustion engines research, especially finding sustainable alternatives to fossil fuels and reducing diesel PM emissions. Fatty acid methyl esters (FAME), including RME, are renewable fuels commonly used from low level blends with diesel to full substitution. They strongly reduce the net carbon dioxide emissions. It is largely unknown how the emissions and characteristics of PM get altered by the combined effect of adding biodiesel to diesel and implementing modern engine concepts that reduce nitrogen oxides (NOx) emissions by exhaust gas recirculation (EGR). Therefore, the exhaust from a single-cylinder Scania D13 heavy-duty (HD) diesel engine fuelled with petroleum-based MK1 diesel, RME, and a 20% RME blend (B20), was sampled while the inlet oxygen concentration was stepped from ambient to very low by varying EGR. Regulated gaseous emissions, mass of total black carbon (BC) and organic aerosol (OA), particle size distributions and the soot nanostructure by means of transmission electron microscopy (TEM), were studied. For all EGR levels, RME showed reduced BC emissions (factor 2 for low and 3-4 for higher EGR) and total particulate number count (TPNC) compared with diesel and B20. B20 was closer to diesel than RME in emission levels. RME opens a significant possibility to utilise higher levels of EGR and stay in the region of low NOx, while not producing more soot than with diesel and B20. Adding EGR to 15% inlet O2 did not affect the nanostructure of PM. A difference between the fuels was noticeable: branched agglomerates of diesel and RME were composed of many primary particles, whereas those of B20 were more often “melted” together (necking).
Novakovica, Maja, Shamun, Sam, Malmborg, Vilhelm B., Kling, Kirsten I., Kling, Jens, Vogel, Ulla B., Tunestal, Per, Pagels, Joakim, Tuner, Martin
An Effect of Utilization B30 from Various Blends of B0:FAME and HVO on Emissions, Fuel Consumption and Power of Euro4 Vehicle Technology2019-01-218912/19/2019
Indonesia has implemented mandatory for utilization of high ratio biodiesel starting from B10 (10% of biodiesel and 90% of diesel fuel by volume) in 2013 then it gradually increased to B20 in 2016 and B30 in 2020. On the other hand, Indonesian Government will also strengthen vehicle emission regulation from Euro 2 to Euro4 in 2021. Therefore, B0 (low sulfur diesel fuel) and B100 (biodiesel) fuel properties as blended fuel for B30 must be improved to comply with Euro4 vehicle emission regulation. In this study various formulation of B30 were investigated, in which the B100 was varied from FAME (fatty Acid Methyl Ester), HVO (Hydrotreated Vegetable oil), and blend of FAME and HVO. The test was conducted under Euro4 vehicle technology to investigate their effect on emissions, fuel consumption and power. In this experiment, emission, fuel consumption and power were tested using UN-ECE R83-05 regulation, UN-ECE R101 and acceleration method respectively. The results showed that B30 has lower CO, HC and particulate emission compared with B0. However, NOx emission for some formulation slightly increased. Moreover, B30 could comply with emission limit, as stated under Euro4 regulation. Fuel consumption for B30 with some formulation was 2-3% higher than that of B0, but it was about the same between B0 and B30 with optimization ratio of FAME and HVO.
Setiapraja, Hari, Yubaidah, Siti, Ekasari, Mutia, Haspriyanti, Nita, Rustyawan, Wawan, Rochim, Abdul
Impact of Engine Oil Additives on Nanostructure and Oxidation Kinetics of Diesel and Synthetic Biodiesel Particulate Matters using Electron Microscopy2019-01-235112/19/2019
Physicochemical characteristics of particulate matters which are influenced by engine oil additives from engine combustion of diesel and synthetic biodiesel: hydrotreated vegetable oil (HVO) were successfully investigated using electron microscopy, electron dispersive x-ray spectroscopy and thermogravimetric analysis. The agglomerate structure of diesel PM, HVO PM and diesel blending lubricant PM are similar in micro-scales. However, nanostructure of soot is a spherical shape composed of curve line crystallites while the metal oxide ash nanostructure is composed of parallel straight line hatch patterns. The oxidation kinetics of fuel blending lubricant PMs are higher than neat fuel PMs due to catalytic effect of incombustible metal additives from engine lubricating oil.
Koko, Phyozin, Karin, Preechar, Charoenphonphanich, Chinda, Chollacoop, Nuwong, Hanamura, Katsunori
Injection Strategies for Isobaric Combustion2019-01-226712/19/2019
In a previous study, we demonstrated that the isobaric combustion cycle, achieved with a split injection strategy, can be more suitable for the double compression expansion engine concept than the conventional diesel combustion cycle. The present work is focused on understanding the effect of different injection strategies on the heat release, efficiency, and emissions of isobaric combustion at the peak cylinder pressure of 150 bar. In situ injection rate measurements are performed to improve our understanding of the heat release rate shape and pollutant formation. A variation of load is performed to demonstrate the feasibility of the isobaric combustion cycle at higher loads, and the means of achieving them. The thermal efficiency reduces at lower loads because of heat losses. It peaks at a medium load point before reducing again at higher loads because of exhaust losses. The effect of altering the injection strategy on the isobaric combustion cycle is also studied at a constant equivalence ratio. The alteration of injection strategy is proven to have minimal effect on efficiency, loss mechanisms, and emissions when more than one injection is used.
Babayev, Rafig, Houidi, Moez Ben, Shankar, VS Bhavani, Aljohani, Bassam, Johansson, Bengt
Numerical Simulations of Methanol Engine Performance for High-altitude, Non-road Applications2019-01-223312/19/2019
Ambient pressure and temperature are two main factors affecting the engine performance. As altitude increases, the air volume and air temperature entering the cylinder per cycle decrease due to the lowering of atmospheric pressure and temperature, which directly affects the engine performance. As a result, engine performance in the plateau environment degrades while the power, economy, and emission performance of the engine significantly deteriorate. This paper focuses on the simulation and parameter optimization of the combustion process of non-road methanol engines, and 1D simulation is for BSFC (Brake Specific Fuel Consumption) prediction while 3D simulation is for soot and NOx (Nitrogen Oxides) predictions. Discusses, analyzes and predicts the feasibility of non-road methanol engines for high altitude conditions. Especially the application of high proportion of methanol in non-road methanol engines at high altitudes. It provides numerical simulations based on the Yuchai YC6M series heavy-duty direct-injection ignition engine and corresponding engine bench test data which elucidate the effects of oxygen-containing methanol fuel on engine performance. The role of methanol in the blend as well as resulting changes in engine power and emissions were investigated; results show that methanol mass fraction of about 40% yields the slowest engine power reduction rate at high altitude. The results also show that the NOx emissions of the engine slowly decrease as altitude increases, by about 4% at altitude of 4000 m; the soot emissions increase as altitude increases.
Yao, Guang, Zhou, Lei, Chen, Zeyu, Weng, Li, Liu, Ke, Zhu, Zan
Combustion Optimization and In-Cylinder NOx and PM Reduction by Using EGR and Split Injection Techniques2019-28-256011/21/2019
Nowadays, the major most challenge in the diesel engine is the oxides of nitrogen (NOx) and particulate matter (PM) trade-off, with minimal reduction in Power and BSFC. Modern day engines also rely on expensive after-treatment devices, which may decrease the performance and increase the BSFC. In this paper, combustion optimization and in-cylinder emission control by introducing the Split injection technique along with EGR is carried out by 1-D (GT- POWER) simulation. Experiments were conducted on a 3.5 kW Single-cylinder naturally aspirated CRDI engine at the different load conditions. The Simulation model incorporates detailed pressure (Burn rate) analysis for different cases and various aspects of ignition delay, premixed and mixing controlled combustion rate, the injection rate affecting oxides of nitrogen and particulate matter. The predictive combustion model (DI-PULSE) has been developed for the calibration of an engine under multiple injections and the detailed injection rates with EGR rates. Split injection with higher fuel quantity injected in the 1st pulse, helped to significantly reduce PM emissions. This reduction is due to the restraint in the premixed phase of the 2nd pulse combustion. Split injections technique is helpful to effectively reduce NOx as well as PM emissions, as compared to increasing dilution rates and injection pressure (700 to 1000 bar) using Cooled EGR and retarding the injection timing. It is noted that for a case of 60(10)40 retarded to injection timings of 20°bTDC, 18°bTDC and 16°bTDC from 23°bTDC has resulted in 31.32% reductions in soot emissions and 38.23% reduction in NOx emissions. Results showing that the simultaneous reduction in NOx emissions and PM emissions is possible with an optimized combination of Split injections & the EGR, under different load conditions and the experimental values are almost matching with the 1-D simulation.
Kumar, Madhan, Jain, Aatmesh, Chhaganlal Vora, Kamalkishore
Development of Diesel Particulate NOx Reduction DPNR System for Simultaneous Reduction of PM and NOx in Diesel Engines2019-28-255411/21/2019
The Diesel Particulate NOx Reduction (DPNR) system is used for simultaneous reduction of PM and NOx in diesel engine. DPF is used to trap particulate matter in diesel engines. NOx absorber technology removes NOx in a lean (i.e. oxygen rich) exhaust environment for both diesel and gasoline lean-burn GDI engines. The NOx storage and reduction catalyst is uniformly coated on the wall surface and in the fine pores of a highly porous filter substrate. Combination of these two components in the DPNR results in a compact size of the system. The base diesel engine model validated with pressure crank angle diagram and performance parameters such as Indicated mean effective pressure. This base engine’s exhaust emission is given as an input to the DPNR system. The surface reaction is connected to the DPF through chemcon template. The surface reaction is NOx storage and reduction chemical kinetics like Lean NOx Trap. The modelling of DPNR and Base engine is done using GT-SUITE. This paper describes about the 1D simulation of DPNR system with base diesel engine model and the percentage reduction of PM and NOx from the base model.
Parthiban, E., Jain, Aatmesh, Chhaganlal Vora, Kamalkishore
Experimental Investigation on Performance and Emission Characteristics of a Single Cylinder CRDI Engine Fueled with Diesel-Methanol Blend2019-28-238011/21/2019
Diesel engine is widely used for its high thermal efficiency and better fuel efficiency. However, increasing usage of petroleum fuel and environmental degradation motivates to use renewable biofuel as a replacement to conventional diesel. Biofuel produced from non-edible sources can be used as a partial substitute of diesel for the significant growth of fuel economy and reduction of environmental pollution. Methanol can be implemented as a blend fuel in the diesel without affecting engine design. In this paper, we study the effect of diesel-methanol blends and injection parameters in particular, start of injection (SOI) and fuel injection pressure (FIP) on a common rail direct injection (CRDI) diesel engine performance and emission were investigated. Four blends were prepared by mixing diesel with methanol (5%, 10%, 15% and 20% by mass) and adding a certain amount of oleic acid and Iso-butanol to get a stable blend. Experiments were performed at an engine speed and load of 1500 rpm and 15 Nm, respectively. FIP governs air-fuel mixture preparation and fuel atomization which control combustion behavior of the engine, whereas SOI was chosen to optimize the combustion delay affecting the overall performance. Results show that the trend of optimum SOI retards 15°, 12° and 5° CA bTDC with the increase in FIP of 200, 300 and 400 bar respectively. However, this does not hold good for M15 and M20 blend at 400 bar FIP due to ignition delay at higher fraction methanol blend. In comparison to baseline diesel, brake specific fuel consumption (BSFC) increases in diesel-methanol blend, which reduces the brake thermal efficiency (BTE). Methanol blend shows a significant impact on the reduction of smoke opacity in all blend fraction compared to baseline diesel operation. This further reduces on advancing SOI and increase in FIP. This mainly attributes the presence of oxygen molecule in methanol as well as sufficient time availability for air-fuel mixing. Higher spray penetration at high FIP removes the deficiency of local oxygen concentration in different regions of the combustion chamber. CO emission shows a negative impact on performance output at all blend fraction, which reduces on advancing SOI and increasing FIP. HC emission shows a similar trend to that of CO, however, at high FIP for all blend fraction, HC emission is lower than the baseline engine due to better mixing and more oxygen availability. The results indicate that methanol blend is an encouraging alternative for lower smoke at the cost of CO and HC emissions. Altogether, it is concluded that diesel-methanol blends can be suitably used in CRDI diesel engines after making a good trade-off between performance and emission.
Sahoo, Sridhar, Nayak, Chinmay, Tripathy, Srinibas, Srivastava, Dhanajay
Effect of Injector Cone Angle and NTP on Performance and Emissions of BS6 Engine2019-28-010810/11/2019
The combustion phenomenon of diesel engines has got a very major impact on the performance and exhaust emission levels. Several important factors like engine components design, combustion chamber design, Exhaust gas recirculation, exhaust after treatments systems, engine operating parameters etc. decide the quality of combustion. The role of fuel injector is crucial on achieving the desired engine performance and emissions. Efficient combustion depends on the quantity of fuel injected, penetration, atomization and optimum timing of injection. The nozzle through flow, cone angle, no of sprays and nozzle tip penetration are the factors which lead to the selection of perfect injector for a given engine. This paper focusses on the selection of the best fit injector suiting the BS6 application on evaluating the performance and emission characteristics. Injectors used were with varying cone angles and NTP. The nozzle tip protrusion of the injectors were varied by changing the sealing washer thickness. With all the above injector configurations, the performance and emission were thoroughly analysed at every level. Final confirmation of the configuration was selected based on the Power & Torque, Fuel consumption, smoke, exhaust temperatures.
Muthusamy, Anbarasu, Shangar Ramani, Vagesh, Sinha, Pranav Kumar
Experimental Test on the Feasibility of Passive Regeneration in a Catalytic DPF at the Exhaust of a Light-Duty Diesel Engine2019-24-00459/9/2019
Diesel engines are attractive thanks to good performance in terms of fuel consumption, drivability, power output and efficiency. Nevertheless in the last years, increasing restrictions have been imposed to particulate emissions, concerning both mass (PM) and number (PN). Different technologies have been proposed to meet emissions standards and the wall-flow Diesel Particulate Filter (DPF) is currently the most common after-treatment system used to trap PM from the exhaust gases. This technology exhibits good features such that it can be regenerated to remove any accumulation of PM. However, this process involves oxidation of the filtered PM at a high temperature through after and post fuel injection strategies, which results in an increase of fuel consumption and may lead to physical damages of the filter in the long term. This work deals with the experimental testing of a catalytic silicon carbide (SiC) wall flow DPF, aiming at decreasing the soot oxidation temperature. The catalyst (CuFe2O4) was deposited on the filter by means of an optimized procedure based on a preliminary controlled chemical erosion of the SiC porous structure. In this way, a uniform distribution of the catalyst on the surface of the filter and in its internal porosities can be obtained. The experimental tests were performed at the exhaust of a EURO V light duty Diesel engine, operating at different speed/load conditions. The results evidence a filtration efficiency higher than 96%, throughout the soot accumulation phase, and, more importantly, a constant value of pressure drop (meaning that the soot oxidation rate equals its deposition rate) at the temperature of 320°C. A further increase of the temperature up to 340 °C, achievable by a small adjustment of engine load, a decrease of the pressure drop is observed, thus evidencing the occurrence of passive regeneration.
Rossomando, Bruno, Arsie, Ivan, Meloni, Eugenio, Palma, Vincenzo, Pianese, Cesare
Oxy-Fuel HCCI Combustion in a CFR Engine with Carbon Dioxide as a Thermal Buffer2019-24-01199/9/2019
Global warming and the increasingly stringent emission regulations call for alternative combustion techniques to reduce CO2 emissions. Oxy-fuel combustion is one of those techniques since the combustion products are easily separated by condensing the water and storing CO2. A problem associated with the burning of fuel using pure oxygen as an oxidant is that it results in high adiabatic flame temperature. This high flame temperature is decreased by introducing a thermal buffer to the system. A thermal buffer in this context is any gas that does not participate in combustion but at the same time absorbs some of the released heat and thus decreases the temperature of the medium. Many experiments have been conducted to study oxy-fuel combustion in ICE using noble gases as thermal buffers. However, those experiments focused on using hydrogen as a fuel to avoid any build-up of CO2 in the system. On the contrary, the work presented in this paper investigates using CO2 as a thermal buffer for oxy-fuel combustion in HCCI engines. Experiments were performed on a standard Waukesha variable compression ratio cooperative fuel research CFR engine, modified to run in HCCI mode. Emissions were measured using an AVL SESAM-i60 FTIR spectrometer. As expected, results showed that the CO2 mixture degraded engine efficiency. The relatively lower engine temperature also decreased NOx emissions, simultaneously increasing CO and unburned hydrocarbon (UHC) emissions.
Mohammed, Abdulrahman, MASURIER, JEAN-BAPTISTE, Elkhazraji, Ali, Johansson, Bengt, Mohammed, Abdulrahman, MASURIER, JEAN-BAPTISTE, Elkhazraji, Ali, Johansson, Bengt
Reduction of NO x in a Single Cylinder Diesel Engine Emissions Using Selective Non-Catalytic Reduction (SNCR) with In-Cylinder Injection of Aqueous Urea2019-24-01449/9/2019
The subject of this study is the effect of in-cylinder selective non-catalytic reduction (SNCR) of NOx emissions in diesel exhaust gas by means of direct injection of aqueous urea ((NH2)2CO) into the combustion chamber. A single cylinder diesel test engine was modified to accept an electronically controlled secondary common rail injection system to deliver the aqueous urea directly into the cylinder during engine operation. Direct in-cylinder injection was chosen to ensure precise delivery of the aqueous urea without the risk of any premature reactions taking place. The injection strategy was four molar ratios, 4.0, 2.0, 1.0 and 0.5 with five varying injection timings of 60, 20, 10, 0, and -30 degrees after top dead center (ATDC). The main secondary injection fluid, aqueous urea, was mixed with glycerol (C3H8O3) in an 80-20 ratio, by mass, with the desire to function as a lubricant for the secondary injector. In addition to the base line and aqueous urea tests, neat water injection and an 80-20 ratio, by mass, water-glycerol solution tests were also conducted to compare the effects of said additives as well. The data collected from the engine tests showed that the aqueous urea-glycerol solution secondary had no effect on the reduction of NOx and even resulted in an increase of up to 5% in some tests. This was due to the low average in-cylinder temperature as well as increasing the required residence time, prohibiting the reduction reaction from taking place. The neat water and water-glycerol solution secondary injection was found to have a reduction effect of up to 59% on NOx production in the emissions due to the evaporative cooling effect and increased heat capacity of the water.
Timpanaro, Anthony, Nuszkowski, John
Smart Cylinder Deactivation Strategies to Improve Fuel Economy and Pollutant Emissions for Diesel-Powered Applications2019-24-00559/9/2019
Further improvement of the trade-off between CO2 and pollutant emissions is the main motivating factor for the development of new diesel engine concepts, from light-duty car applications via medium-duty commercial vehicles up to large long-haul trucks. The deactivation of one or more cylinders of a light-duty diesel engine during low load operation can be a sophisticated method to improve fuel economy and reduce especially NOx emissions at the same time. Dynamic Skip Fire (DSF) is an advanced cylinder deactivation technology, where the decision to fire or skip singular units of a multi-cylinder engine architecture is taken just prior to each firing opportunity, based on a balanced rankling of multiple input parameters. A DSF-equipped engine incorporates the ability to selectively deactivate cylinders on a cylinder event-by-event basis for best matching of the requested driver’s torque demand at optimum fuel efficiency, while ensuring no drawback in terms of drivability with respect to fully firing engine. Dynamic Skip Fire has already demonstrated significant fuel economy improvements for throttled spark-ignition engines on a number of different applications. The publication presents the potential of the DSF technology in improving fuel economy while supporting the realization of ultra-low tailpipe emissions for small cylinder displacements as well as bigger cylinder bore diesel applications, covering LD as well as MD Diesel powertrains. The simulation activity has been carried out using an advanced, internally developed FEV Powertrain Simulation Platform. A representative state-of-the-art 4-cylinder 2.0-liter LD Diesel engine definition has been analyzed. Simulation results highlighted a significant CO2 benefit both on WLTC as well as RDE cycle. The analysis results obtained so far demonstrate that DSF technology, when applied to a light-duty diesel engine with optimized transmission shift scheduling, can achieve up to 0.5% to 1.5% fuel economy benefit, while realizing tailpipe nitrogen oxides (NOx) emissions reduction up to 33%. The reduction of tailpipe NOx is achieved mainly by improved conversion efficiency in the NOx aftertreatment system due to increased exhaust temperatures with DSF technology. The investigations have been extended to a larger 6-cylinder 7.7-liter MD Diesel engine application for commercial applications. On this heavier application DSF shows approximately 50% reduction in terms of tailpipe NOx both on the European and American MD legislation cycle, together with a CO2 benefit respectively of 2.5 and 3.5%.
Scassa, Mauro, Körfer, Thomas, Chen, S Kevin, Fuerst, John, Younkins, Matthew, Nencioni, Marco, George, Shino
Assessment of Hydrotreated Vegetable Oil (HVO) Applicability as an Alternative Marine Fuel Based on Its Performance and Emissions Characteristics04-12-02-00075/16/2019
In current study, the combustion and emission characteristics of hydrotreated vegetable oil (HVO) were studied and compared to those of conventional marine gas oil (MGO). The main goal was to verify its applicability as an alternative marine fuel. All experiments were performed using generator set and propeller-law test cycles, i.e., standardized E2 and E3 cycles respectively. Additional emphasis was paid to the particulate matter (PM) emissions combining gravimetric and particle number measurements. The obtained results indicate average 10-15 % reduction in nitrogen oxides (NOx) emissions, while total unburned hydrocarbons (THC) emissions were reduced by 50-55 %. It is believed that a much higher cetane number of HVO together with its superior chemical composition (overall higher H/C ratio, absence of aromatics and heavy-boiling compounds) plays a vital role here. This may also explain the observed around 30 % PM mass reduction, which however showed a strong dependence on load (fuel-air ratio) and speed (time available for combustion) settings. Measured particle size distributions showed a clearly unimodal nature for both the tested fuels with pronounced accumulation (soot) mode found at around 60-80 nm. The total particle concentration in the measured size range of 14-750 nm was almost 30 % higher for HVO than for MGO. This increase is mainly associated with an increase in the number of produced nanoparticles. The main reason for that is most likely the less-optimal injection (shorter penetration length with larger cone angle due to lower density and longer injection duration related to lower volumetric energy content of HVO). The latter negative factors were however counterweighted by the advantages in terms of better chemical composition/structure resulting in an overall better combustion of HVO.
Ushakov, Sergey, Lefebvre, Nicolas
Ultra-Low NOx Emission Prediction for Heavy Duty Diesel Applications Using a Map-Based Approach2019-01-09874/2/2019
As vehicle emissions regulations become increasingly stringent, there is a growing need to accurately model aftertreatment systems to aid in the development of ultra-low NOx vehicles. Common solutions to this problem include the development of complex chemical models or expansive neural networks. This paper aims to present the development process of a simpler Selective Catalytic Reduction (SCR) conversion efficiency Simulink model for the purposes of modeling tail pipe NOx emission levels based on various inputs, temperature shifts and SCR locations, arrangements and/or sizes in the system. The main objective is to utilize this model to predict tail pipe NOx emissions of the EPA Federal Test Procedures for heavy-duty vehicles. The model presented within is focused exclusively on heavy-duty application compression ignition engines and their corresponding aftertreatment setups. The accuracy of the model depends heavily on the ability to gain precise and repeatable test cell data to calculate an expansive SCR conversion efficiency map for the given aftertreatment system. This conversion efficiency map is verifiable based on expected/known chemical and physical properties of SCR aftertreatment systems. For this application, a 2-dimensional map was created, using SCR temperature and space velocity. The model requires several inputs including engine out NOx concentrations, SCR temperature, and exhaust flow/space velocity to input into the table and thus predict the corresponding tail pipe NOx. While different engine calibrations can impact the accuracy of the model, it was found that error in average tail pipe NOx prediction (g/bhp·hr) was approximately +/- 10%. For the purposes of this model, this error was found to be sufficient in providing the proper direction for ultra-low NOx aftertreatment development.
Singh, Navtej, Adelman, Brad, Malagari, Srinivasulu, Hickey, Kyle
Experimental and Computational Study of DOC on CSF for Heavy Duty Diesel Applications2019-01-05864/2/2019
For diesel exhaust aftertreatment applications with space limitations, as well as to move the selective catalytic reduction system (SCR) to a warmer location closer to the engine, DOC on CSF technology can be used. This technology combines the diesel oxidation catalyst (DOC) and catalyzed soot filter (CSF) functionalities in one component, thereby enabling volume reduction. DOC on CSF maintains the abatement of hydrocarbon (HC), carbon monoxide (CO), and particulate matter (PM), and the oxidation of nitric oxide (NO) to nitrogen dioxide (NO2) for passive soot oxidation and fast SCR reaction of NOx on a downstream SCR catalyst. In this study, the performance of DOC on CSF was compared to a DOC + bare diesel particulate filter (DPF) and a DOC + CSF system, to understand the performance benefits and challenges. All the components were optimized individually for their respective functions. The DOC on CSF was optimized for NO oxidation and passive soot oxidation performance. Experimental data and simulations were used to understand the underlying mechanisms in the DOC on CSF technology. Steady state HC oxidation under active regeneration conditions showed a benefit for DOC on CSF compared to the DOC + DPF system. The soot oxidation characteristics of the DOC on CSF were evaluated in comparison to a DPF or CSF downstream of a DOC under passive and active soot oxidation conditions. In addition, the contribution of NO2 generated within the filter on the soot oxidation was assessed. The passive soot oxidation characteristics of a DOC on CSF were found to be similar, or better, compared to DOC + DPF and DOC + CSF under certain conditions. The active regeneration efficiency was lower for the DOC on CSF due to the gradual increase in temperature along the length of the part during fuel injection. This work demonstrates the differences between the DOC on CSF and DOC + bare/coated DPF systems, thus enabling a better understanding of the performance of DOC on CSF to current applications.
Sethuraman, Sharan, Sitamraju, Siddarth, Lopez-De Jesus, Yaritza M, Markatou, Penelope
Ash Transport and Deposition, Cake Formation and Segregation-A Modeling Study on the Impact of Ash on Particulate Filter Performance2019-01-09884/2/2019
Non-combustible particles, commonly summarized as ash, influence the lifetime performance of wall flow filters. This study aims to investigate this influence by means of simulation. An existing transient 1D+1D wall flow filter model is extended by dedicated transport balances for soot and ash (1), by a discrete cake model describing changing soot and ash compositions over the cake height (2), by a phenomenological cake filtration model (3), by dedicated cake property models (4) and by a phenomenological model capturing the radial mobility of solids within the cake (5). Results of three different types of simulations are shown. First, the various sub-models are assessed in isolated simulation configurations. The combination of these shall serve as theoretical model validation. Second, isolated loading and passive regeneration simulations are performed. This aims to identify the impact of different filtration and cake migration constants on soot and ash segregation (i.e. ash accumulation) and on soot conversion performance. Third, the impact of ash during a combined loading and passive regeneration cycle is investigated. This aims to identify the impact of ash on the formation of a soot balance point.
Wurzenberger, Johann C., Kutschi, Susanne, Nikodem, Astrid
Sensitivity Study on Thermal and Soot Oxidation Dynamics of Gasoline Particulate Filters2019-01-09904/2/2019
Gasoline particulate filters (GPFs) are devices used to filter soot emitted by gasoline direct injection (GDI) engines. A numerical model for a ceria-coated GPF presented in a previous paper by H. Arunachalam et al. in 2017 was developed to predict internal temperature and soot amount combusted during regeneration events. Being that both the internal temperature and the accumulated soot cannot be directly measured during real-time operation and owing to their critical importance for GPF health monitoring as well as regeneration scheduling, the above model turns out to be a valuable tool for OBD applications. In this paper, we first conduct a stochastic analysis to understand the relation between the model parameters and the initial value of the ceria (IV) oxide volume fraction, as a deterministic value for such a state is not known. A particle swarm optimization (PSO) algorithm was employed to define what type of relationship the model parameters were with respect to the initial state of the ceria (IV) oxide volume fraction. A sensitivity study is then conducted over the model parameters to study parameter identifiability from system measurements. Effects of the initial temperature and initial amount of soot were studied as well. Results indicated that the model is most sensitive to the activation energy of GPF regeneration, agreeing with previous studies. Additionally, the model was shown to be able to predict the GPF temperature with less than 5% error when there was at most 20% uncertainty in the parameters. The results of the relationship between ceria (IV) oxide and the parameters, as well as the sensitivity analysis can be used simultaneously in the future for observer-based design.
Takahashi, Aki, Korneev, Slava, Onori, Simona
Dilution and Injection Pressure Effects on Ignition and Onset of Soot at Threshold-Sooting Conditions by Simultaneous PAH-PLIF and Soot-PLII Imaging in a Heavy Duty Optical Diesel Engine2019-01-05534/2/2019
Although accumulated in-cylinder soot can be measured by various optical techniques, discerning soot formation rates from oxidation rates is more difficult. Various optical measurements have pointed toward ways to affect in-cylinder soot oxidation, but evidence of effects of operational variables on soot formation is less plentiful. The formation of soot and its precursors, including polycyclic aromatic hydrocarbons (PAHs), are strongly dependent on temperature, so factors affecting soot formation may be more evident at low-temperature combustion conditions. Here, in-cylinder PAHs are imaged by planar laser-induced fluorescence (PAH-PLIF) using three different excitation wavelengths of 355, 532, and 633 nm, to probe three different size-classes of PAH from 2-3 to 10+ rings. Simultaneous planar laser-induced incandescence of soot (soot-PLII) using 1064-nm excitation provides complementary imaging of soot formation near inception. To achieve low combustion temperatures at the threshold of PAH and soot formation, the engine operating conditions are highly diluted, with intake-O2 mole-fractions as low as 7.5%. The optical diagnostics show that increasing dilution delays the inception of PAH by over 2.5 ms as the intake-O2 mole-fraction decreases from 15.0% to 9.0%. At 7.5% intake-O2, no large PAH or soot are formed, while the 9.0% intake-O2 condition forms PAH but virtually no detectable soot. Conditions with 10.0% or more intake-O2 form both PAH and soot. For the threshold-sooting condition with 10.0% intake-O2, large PAH typically forms broadly throughout the cross-section of the downstream jets and along the bowl-wall. Soot appears after PAH, and in narrower ribbons in the jet-jet interaction region. These soot ribbons are on the periphery of the PAH, near the diffusion flame, where the highest temperatures are expected. With increasing intake-O2, the delay time between soot and PAH shortens, and soot tends to shift upstream to the jet region prior to wall impingement, though still on the periphery of the PAH. The spatial distributions of PAH and soot overlap slightly under these threshold-sooting conditions, with soot typically surrounding the PAH. This may indicate that temperatures are only high enough for soot formation on the jet periphery, near the diffusion flame. The minimal overlap also suggests that PAHs are rapidly consumed and/or adsorbed when soot is formed. Additionally, increasing the fuel-injection pressure from 533 to 800 and then to 1200 bar increases soot and large PAH formation, which is opposite to the trend for conventional diesel combustion.
Li, Zheming, Roberts, Gregory, Musculus, Mark
High-Load Compression-Ignition Engine Emissions Reduction with Inverted Phi-Sensitivity Fuel Using Multiple Injection Strategies2019-01-05544/2/2019
Inverted phi (ϕ)-sensitivity is a new approach of NOx reduction in compression-ignition (C.I.) engines. Previously, pure ethanol (E100) was selected as the preliminary test fuel in a single injection compression-ignition engine, and was shown to have good potential for low engine-out NOx emissions under low and medium load conditions due to its inverted ignition sequence. Under high load, however, the near-stoichiometric and non-homogeneous fuel/air distribution removes the effectiveness of the inverted ϕ-sensitivity. Therefore, it is desirable to recover the combustion sequence in the chamber such that the leaner region is burned before the near-stoichiometric region. When the combustion in near-stoichiometric region is inhibited, the temperature rise of that region is hindered and the formation of NOx is suppressed. To achieve the goal of homogenizing the mixture before combustion, thus switching ignition mode and lowering emissions when fueling with the target fuel, multiple direct-injection strategies are applied to this study. 3-D engine CFD simulations are conducted with different multiple injection strategies under high-load operations in a compression-ignition engine. The injection characteristics of optimized cases are examined in KIAV-3V coupled with a Genetic Algorithm(GA). An objective function is used to qualify the realization of optimized cases with minimized engine-out NOx, carbon monoxide (CO), soot and unburned hydrocarbon (UHC), while preserving engine performance. It is found that with multiply direct-injection strategies, the desired inverted ϕ-sensitivity dominated ignition can be regained under high-load engine operation conditions, uniform fuel-air mixture before combustion can be retrieved, and lower in-cylinder temperature and pressure are possible. Comparing to the double-injection strategy, the optimized triple-injection strategy shows more pronounced effects in terms of combustion quality and emission reduction.
Gao, Suya, Lee, Chia-Fon
Measurement of Gasoline Exhaust Particulate Matter Emissions with a Wide-Range EGR in a Heavy-Duty Diesel Engine2019-01-07614/2/2019
A large number of measurement techniques have been developed or adapted from other fields to measure various parameters of engine particulates. With the strict limits given by regulations on pollutant emissions, many advanced combustion strategies have been developed towards cleaner combustion. Exhaust gas recirculation (EGR) is widely applied to suppress nitrogen oxide (NOx) and reduce soot emissions. On the other hand, gasoline starts to be utilized in compression ignition engines due to great potential in soot reduction and high engine efficiency. New engine trends raise the need for good sensitivity and suitable accuracy of the PM measurement techniques to detect particulates with smaller size and low particulate mass emissions. In this work, we present a comparison between different measurement techniques for particulate matter (PM) emissions in a compression ignition engine running on gasoline fuel. A wide-range of EGR was used with lambda varied from 3 down to 1. The compared equipment includes AVL smoke meter, AVL Micro Soot Sensor, Pegasor and Cambustion Differential Mobility Spectrometer (DMS). The goal of this paper is to compare the recorded values and show the sensitivity of the instruments to soot properties altering, in both lean and stoichiometric combustion situations.
Shen, Mengqin, Shamun, Sam, Tunestal, Per, Tuner, Martin
On Developing Advanced Catalysts Systems to Meet China New Regulations2019-01-09784/2/2019
Over the past few years, China has made major legislative advancements on vehicle emissions, having set forth Stage 6 regulations for both LD and HD vehicles. To meet stricter standards, OEMs and associated suppliers of the exhaust aftertreatment value chain have gone through a period of unprecedented development. This paper selectively describes key challenges and highlights corresponding solutions of those development for both segments. In doing so, the authors wish to provide an overview of the catalyst systems used in upcoming China automobile market. A key challenge for LDG Stage 6 is the introduction of FWCTM (Four-Way Catalysts, aka cGPF - Coated Gasoline Particulate Filter). This paper discusses advantages and disadvantages of different system solutions. Experimental study showed oxygen and temperature are critical factors to achieve effective soot regeneration in a FWCTM. Careful debugging and analysis are needed to identify causes in FWCTM system when tail-pipe emissions do not meet the PM and PN targets. The LDD segment is a niche market in China. It however has same level of technical complexity as in Europe when it comes to develop exhaust aftertreatment system to meet Stage 6. Technical trend and mainstream solution for China market are reviewed. The HDD Stage VI is very similar to EU VI regulation. Due to uneven market application and diesel fuel quality, OEMs tend to adopt the conventional DOC+CSF+Cu-SCR system and use proven catalyst technologies. This paper discusses those durability concerns and reviews dedicated experiments for design validation, especially on effect of prolonged thermal aging and high sulfur fuel. The off-road Stage IV standard has strong China attributes. Its gaseous emission limits are same as Europe Stage IIIB however it has a PN requirement not imposed until EU Stage V. This paper discusses possible off-road aftertreatment system pathways, with an emphasis on SCRoF for fit-for-market solution.
Tang, Weiyong, Siani, Attilio, Chen, Frank, Chen, Bob
Engine-Aftertreatment in Closed-Loop Modeling for Heavy Duty Truck Emissions Control2019-01-09864/2/2019
An engine-aftertreatment computational model was developed to support in-loop performance simulations of tailpipe emissions and fuel consumption associated with a range of heavy-duty (HD) truck drive cycles. For purposes of this study, the engine-out exhaust dynamics were simulated with a combination of steady-state engine maps and dynamic correction factors that accounted for recent engine operating history. The engine correction factors were approximated as dynamic first-order lags associated with the thermal inertia of the major engine components and the rate at which engine-out exhaust temperature and composition vary as combustion heat is absorbed or lost to the surroundings. The aftertreatment model included catalytic monolith components for diesel exhaust oxidation, particulate filtration, and selective catalytic reduction of nitrogen oxides (NOx) with urea. Both the engine and aftertreatment models have been calibrated with dynamometer measurements from a commercial 2010-certificated 15-L Cummins diesel engine. The fuel consumption engine map with the reduced data is attached in the appendix. Simulations with the combined engine and aftertreatment models above appear to reveal important trends among the fuel efficiency, emissions control, power demand for HD trucks under realistic drive cycle conditions. Thus, this type of computational simulation appears to have significant value in choosing among options for HD vehicle design and operation.
Gao, Zhiming, Deter, Dean, Smith, David, Pihl, Josh, Daw, C. Stuart, Parks, James
Characterization of Particulate Matter Emissions from Heavy-Duty Partially Premixed Compression Ignition with Gasoline-Range Fuels2019-01-11854/2/2019
In this study, the compression ratio of a commercial 15L heavy-duty diesel engine was lowered and a split injection strategy was developed to promote partially premixed compression ignition (PPCI) combustion. Various low reactivity gasoline-range fuels were compared with ultra-low-sulfur diesel fuel (ULSD) for steady-state engine performance and emissions. Specially, particulate matter (PM) emissions were examined for their mass, size and number concentrations, and further characterized by organic/elemental carbon analysis, chemical speciation and thermogravimetric analysis. As more fuel-efficient PPCI combustion was promoted, a slight reduction in fuel consumption was observed for all gasoline-range fuels, which also had higher heating values than ULSD. Since mixing-controlled combustion dominated the latter part of the combustion process, hydrocarbon (HC) and carbon monoxide (CO) emissions were only slightly increased with the gasoline-range fuels. In contrast, soot emissions were significantly reduced with the gasoline-range fuels, including a ~70% reduction in micro soot sensor measurements and a >50% reduction in smoke meter measurements. All gasoline-range fuel PM samples were also found to contain higher amount of volatile species and organic carbon fractions compared to ULSD PM samples as measured by thermogravimetric and EC-OC analyses. Various partially oxidized HC species and nitrophenolic compounds were also detected by TDP-GC-MS and CE-MS techniques, which indicated that more pronounced PPCI combustion occurred with the gasoline-range fuels. Overall similar PM oxidation behavior was observed despite the differences in reactivity and chemical properties of the fuels, although there may be some significant impacts under certain operating conditions.
Lee, Jong, Tzanetakis, Tom, Zhang, Yu, Traver, Michael, Lewis, Sam, Moses-DeBusk, Melanie, Storey, John
Impact of CO 2 Dilution on Ignition Delay Times of Iso-Octane at 15% and 30% Dilution Levels in a Rapid Compression Machine2019-01-05694/2/2019
Iso-Octane (2,2,4-trimethlypentane) is an important gasoline primary reference fuel (PRF) surrogate. Auto ignition of iso-octane was examined using a rapid compression machine (RCM) with iso-octane, air and carbon dioxide (CO2) mixtures. Experiments were conducted over a temperature range of 650K-900K at 20bar and 10 bar compressed conditions for equivalence ratios (Φ =) 0.6, 0.8, 1.0 and 1.3. CO2 dilution by mass was introduced at 0%, 15% and 30% levels with the O2:N2 mole ratio fixed at 1:3.76 emulating the exhaust gas recirculation (EGR) substitution in spark ignition (SI) engines. In this study the direct test chamber (DTC) approach is used for introducing iso-octane directly into the RCM test chamber via a direct injector. The results using this approach are compared with other RCM data available in the literature at undiluted Φ = 1.0 and 20 bar compressed pressure and show good agreement. For a given equivalence ratio, the negative temperature coefficient (NTC) region was fixed irrespective of the dilution levels confirming the fact that CO2 does not participate in the chemistry of the base fuel but rather reduces the reactivity leading to increased ignition delay times. At 30% dilution levels the increase in ignition delay times is more than twice that of the 15% dilution levels for the same compressed conditions and stoichiometry.
Chinnathambi, Prasanna, Wadkar, Chaitanya, Toulson, Elisa
A Real-Time Control Framework for Integrated Diesel Engine and Selective Catalytic Reduction System2019-01-12874/2/2019
Diesel engines have been widely adopted in medium- to heavy-duty ground vehicles, due to high engine efficiency, high power output, and superior reliability. However, as Diesel engine emission regulation has been significantly tightened in the past decade, emission control has become a major barrier for Diesel engine efficiency improvement. Integrated Diesel engine and aftertreatment system controls are very important for modern Diesel engines to further improve fuel efficiency while facing increasingly stringent NOx and particulate matter (PM) emission regulations. In this paper, a real-time implementable, integrated engine-aftertreatment control framework was proposed to coordinate a modern Diesel engine with the coupled urea-based selective catalytic reduction (SCR) system for achieving close-to-optimal engine efficiency while meeting tight tailpipe NOx and NH3 slip requirements. With engine-out NOx emissions being considered as an additional active control input (other than urea solution injection rate) to the SCR system, both engine fuel efficiency and tailpipe emissions were incorporated in the new multi-input SCR control problem formulation. Nonlinear backstepping-based control allocation algorithms were designed to intentionally increase engine-out NOx emissions without sacrificing the tailpipe emission control performance. With the relaxed engine-out NOx emission constraint, engine start of injection (SOI) timing control was optimized for achieving higher engine efficiency. Simulation results based on experimentally calibrated Diesel engine and aftertreatment system models demonstrated significant fuel saving by 10.86% over the transient US06 cycle with the proposed integrated control, compared to an isolated Diesel engine control. In addition, the computationally-efficient integrated control algorithms can be implemented on the existing engine control units for realizing the fuel saving and emission control benefits in the near future.
Yang, Kuo, Chen, Pingen
Advances in Partial Oxidation of Palm Oil Based Biodiesel Reforming to Hydrogen Production for Diesel Engine Applications2019-01-14123/25/2019
The aims of this research is investigate the hydrogen production via biodiesel fuel partial oxidation reforming. Hydrogen production can enhance combustion in cylinder and improved aftertreatment activities. A reforming reaction is when a chemical reacts with oxygen available in exhaust gas and diesel fuel injection. The 2%Pt-1%Rh-CeO2-ZrO2/γ-Al2O3 was selected as the active catalyst in this research. This study investigates the effect of gas space velocity (SV) (e.g., 10k h-1 and 16k h-1) and fuel addition flow rate (10-30 ml/h) on hydrogen production efficiency. As can be seen that the hydrogen from reforming reaction was promoted under the real engine operating conditions. Hydrogen is produced via partial oxidation of hydrocarbons reforming. The effects of space velocity SV (h−1) and hydrocarbon addition, which enhanced energy input for the reforming process, are the main effect on hydrogen production over the reforming catalyst. The maximum hydrogen yield are achieved 11%. In the future, hydrogen production via partial oxidation fuel reforming could be developed for production of hydrogen on-board the vehicle.
Theinnoi, Kampanart, Sawatmongkhon, Boonlue, Temwutthikun, Warirat, Wongchang, Thawatchai
Q&A19TOFHP02_132/1/2019
In October 2018, Tenneco Inc. completed its “transformational” acquisition of Federal-Mogul LLC, and now is working to realign the businesses and establish two independent companies by late 2019: an Aftermarket and Ride Performance company, and a Powertrain Technology company that will continue to address fuel economy, power output, and criteria pollution requirements for gasoline, diesel and hybrid-electric powertrains across the various regions of the world. The Tenneco name will remain with the Powertrain, or Clean Air, side of the business, according to John Wehrenberg, the leader of the Commercial Truck Off-Highway (CTOH) business for Clean Air. “The most exciting space in truck and off-highway, at the moment, is in the Asian markets, driven by the regulatory changes that are coming less than 18 months from now” with Bharat VI in India and China VI, he said during an interview with Truck & Off-Highway Engineering this past fall. Wehrenberg and Bernd Scherer, Tenneco's Executive Director of Engineering, offered their viewpoints on these markets and other topics. What approach is Tenneco taking to upcoming emissions standards in India and China?
Gehm, Ryan
Experimental Study of Ignition Delay, Combustion, and NO Emission Characteristics of Hydrogenated Vegetable Oil04-12-01-00022/1/2019
In this article, a comparative study of hydrogenated vegetable oil (HVO) and diesel was performed in two constant volume combustion rigs and an optical accessible compression-ignited chamber (OACIC). Ignition, combustion, and nitric oxide (NO) emissions were studied under constant ambient gas density of 16.4 kg/m3, 21% vol oxygen concentration, and two different injection pressures of 800 and 1000 bar. Emission of NO was measured only in the OACIC, while a line-of-sight soot temperature distribution by applying two-color pyrometry was investigated in both setups. In general, the HVO as alternative fuel showed shorter ignition delay and less NO emission than diesel for both injection pressures. Due to difference in the molecular structure, soot temperature of biofuel flames had narrower temperature spectrum than conventional fuel. Moreover, this study reveals the significance of wall-jet interaction for utilization of the biofuel. The HVO was not found to bounce off the wall as conventional diesel, which led to relatively long flame residence time for the tested biofuel. Based on the revealed results, it is clear that a diesel engine operated on biodiesel will be characterized by lower NOx emissions comparatively to the one operated on conventional diesel fuel. This will ultimately lead to reduced energy consumption for exhaust gas aftertreatment in order to comply with environmental regulations. At the same time, the shift toward HVO, due to its both physical and thermodynamic properties, will require additional optimization of combustion chamber geometry and injection system and readjusting the injection strategies and timings.
Krivopolianskii, Vladimir, Bjørgen, Karl Oskar P., Emberson, David, Ushakov, Sergey, Æsøy, Vilmar, Løvås, Terese
Effects of Isotopic Calibration Gases on IR Quantification Analyzer Techniques to Measure CO and CO 2 in Engine Emissions Testing2019-01-00761/15/2019
Infrared spectroscopic methods are the most common methods in the automotive industry for measuring carbon monoxide (CO) and carbon dioxide (CO2) gases. Concentrations of both gases, which are emitted from the combustion of fuels, are required to be determined accurately in order to follow strict environmental regulations. Appropriate analytical techniques and accurate calibration gas mixtures are therefore critical for successful measurements. Regulatory documents such as the EPA’s Code of Federal Regulations 40 (CFR 40) part 1065.250, UN ECE-R83, and (EU) 2017/1151 recommend a nondispersive infrared (NDIR) analyzer to measure CO and CO2 concentrations in raw or diluted exhaust gas samples. Over the last decade, Fourier Transform Infrared (FTIR) spectrometry has been validated and recommended in engine exhaust certification testing as well as in engine and vehicle development activities. The variation in the isotopic ratio of 13C/12C in natural atmospheric CO2 is in the range of ± 2‰ however, artificial or non-natural sources of CO or CO2 can potentially have much larger variances. To fully understand the impacts of isotopic composition on the analyzers, the δ13C values used in this study were selected to cover a broad range of non-natural isotope ratios (very depleted and enriched). In the present work on both FTIRs and NDIRs, up to 4% deviation in analytical results were observed relative to the base case composition (-12‰ 13CO) when the CO/N2 gas mixture was enriched to 2630‰ with 13C content. Analytical deviations measured on NDIR analyzers were more pronounced (4-14%) relative to the base case composition with the change of 13C in the CO2/N2 mixture from -982‰ to 6783‰. Moreover, the error with FTIR measurements could rise up to a factor of 2 or more depending on the 13C and 12C band selection and their evaluation methods. Known isotopic gas mixtures and careful evaluation band selection in the FTIR method were observed to reduce the analytical errors. Even though calibration gases were prepared accurately for molecular concentrations, carbon isotopic concentrations far removed from natural abundance showed significant errors in the measurements. It is therefore essential to have either known or natural ratios of carbon isotope calibration gas mixtures for accurate emission measurements.
Kumar, Anuj, Arlitt, Bertold, Jacksier, Tracey
Integrated AHP and WED Based Approach to Select Optimal Combination of Operating Parameters on Spark Ignition Engine2019-01-00251/15/2019
The influence of operating parameters on the performance of spark ignition engine has attracted the interest of engine manufacturers and researchers. In this instance, selection of optimum criteria of operating parameters based on experimental results is expressed as a multi attribute decision making (MADM) problem. In this study, a mathematical model which is an integration of Analytic hierarchy process (AHP) and Weighted Euclidean distance based approach (WED) is proposed to select optimal combination of operating parameters. The parameters chosen are compression ratio (6,7,8,9), fuel blends (E10, E20, E30, E40) and load (25%, 50%, 75%, 100%). Consistency check of weights of attributes was carried out by AHP and the weighted distance of attributes from the most and least favorable situations was evaluated using WED. Optimum criteria with the combination of compression ratio of 8, fuel blend of E20 at load of 100% was found to be optimum. The results of proposed mathematical model were compared with another MCDM tool, Graph theory matrix approach. The proposed model allows the decision maker to analyze and evaluate the weights of attributes logically and systematically to make decision.
Geetha, Narayanan Kannaiyan, Pappula, Bridjesh
Thermally Durable Zeolite Based SCR Catalysts for Controlling NOx Emissions in Diesel Exhaust to Meet BS VI Norms2019-26-01301/9/2019
From the recent past, automotive exhaust emission management strategies has been progressing towards an alternative for vanadia based selective catalytic reduction (V-SCR) of NOx in diesel powered vehicles. Some of the major inadequacies of existing V-SCR technology were as follows: poor thermal endurance (deteriorates at 550°-600°C), volatilization of harmful vanadium into environment and inadequate NO2 conversion. Metal incorporated zeolite systems, (the metals being preferably selected from transition metal elements), has gained momentum for commercial DeNOx applications. However, the major challenge with this zeolite SCR (Z-SCR) was its low thermal/hydrothermal stability. In the current study, it has been attempted to overcome this by various zeolites and metals combinations. Various combinations of metallic Z-SCR were extensively studied for their low and high temperature activities. The host zeolites were selected on the basis of various properties such as surface area, crystallinity, crystal size and pore opening etc. The active transition metals were also selected based on its affinity to react and attach with the zeolytic framework elements. It has been observed that when the selected transition metal is substituted in small pore zeolites, the resultant Z-SCR gains high thermal and hydrothermal stability. It was also observed that, in addition to the selection of the zeolites & transition metals, the choice of binder, plays a vital role in achieving the required DeNOx activity in the wide temperature range (180°C - 650°C). Z-SCR washcoat derived from above combinations were coated on a ceramic substrate. And the developed new technology washcoats have been undergone proprietary treatment. The washcoats were evaluated for physical properties as well as its DeNOx activity. It was found to have excellent adhesion, high surface area and optimal NH3 adsorption capacity. The coated ceramic substrates were tested on simulated gas test bench (SGTB) for its DeNOx activity and it was found that the total NOx conversion reaches higher than benchmark and meeting BS VI norms. The catalysts have been tested again as aged on the simulated gas test bench for its DeNOx activity and it has been found that the total NOx conversion has been substantially enhance ed.
Muthusamy, Vishnuvarthan, Harkonen, Matti, Kumar, Arvind, Trigunayat, Alok, Rajan, Bosco
48 V Diesel Hybrid - Advanced Powertrain Solution for Meeting Future Indian BS 6 Emission and CO2 Legislations2019-26-01511/9/2019
The legislations on emission reduction is getting stringent everywhere in the world. India is following the same trend, with Government of India (GOI) declaring the nationwide implementation of BS 6 legislation by April 2020 and Real Driving Emission (RDE) Cycle relevant legislation by 2023. Additionally GOI is focusing on reduction of CO2 emissions by introduction of stringent fleet CO2 targets through CAFE regulation, making it mandatory for vehicle manufacturers to simultaneously work on gaseous emissions and CO2 emissions. Simultaneous NOx emission reduction and CO2 reduction measures are divergent in nature, but with a 48 V Diesel hybrid, this goal can be achieved. The study presented here involves arriving at the right future hybrid-powertrain layout for a Sports Utility Vehicle (SUV) in the Indian scenario to meet the future BS 6 and CAFÉ legislations. Diesel engines dominate the current LCV and SUV segments in India and the same trend can be expected to continue in future. An existing SUV from the Indian market has been selected as a target base vehicle for this study. The base SUV vehicle meets the BS 6 legislative requirements with MIDC cycle. The focus is on 48 V P0 and P2 hybrid layout evaluation and optimization through simulation techniques using Matlab/Simulink models. This RDE cycle (Pune RDE), has been developed out of actual vehicle measurement in and around Pune city, capturing real transient vehicle behavior and start-stop / energy recuperation potential availability. The study also includes the effect of these hybridized powertrain architecture on the reduction/optimization of the needed Exhaust After Treatment System (EATS) size as well as fluid consumption, due to reduced engine out NOx emission. Existing vehicle platform is on a 12 V system and migration to a 48 V system will call for additional system and development cost.
Emran, Ashraf, Ehrly, Markus, Sandhu, Rouble, Chavan, Sagar, Sharma, Vijay, Körfer, Thomas
Optimized In Cylinder NOx Reduction Strategy for Meeting BSVI Emission Limits2019-26-01421/9/2019
The tough emission limits of BSVI norms with very low levels of NOx and PM emissions presents major techno economic challenges for the automobile industry. Combined efforts of pollutants reduction by combustion modification as well as the exhaust after treatment devices could only facilitate to achieve the desired emission targets. selective catalytic reduction technology is a mandatory system which uses ammonia from the aqueous urea solution to react with NOx forming nontoxic by products. The cost spent on aqueous urea solution in addition to the cost of BSVI diesel encounters high operating cost for the vehicle. NOx reduction by SCR too requires adequate quantity of ammonia from the AdBlue. Hence sensible utilization of DEF is essential for reduced running cost of the SCR system. SCR efficiency is higher for higher exhaust temperature and it requires minimum exhaust temperature above which only it operates. For conditions like cold start and low temperature combustion, SCR may not be effective and combustion optimization is the only way to reduce NOx. This article focuses on the reduction of NOx emission of the 2.2 l engine on adjustment of EGR rate and Main injection timing on different operating points on various equivalence ratios. The operating points for optimization were determined by conducting various drive trials on different type of road conditions along with consideration of NEDC. NOx, BSFC, soot and CO were measured and studied thoroughly from richer to leaner fuel-air mixtures. Calibration strategy involved the safe limits of NOx, soot, CO emissions and fuel consumption. Combustion optimization for NOx reduction was done keeping the in mind the consumption of DEF as well as diesel and the cost factor of both. Finally the best fit of strategy for reduced NOx and fuel consumption was arrived ensuring lower operating fuel and DEF cost.
Muthusamy, Anbarasu, Shangar Ramani, Vagesh, Sinha, Pranav Kumar, J, Giftson, R, Sivasubramamanian, Halbe, Vasudeo Ganesh
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