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2017-01-10
Technical Paper
2017-26-0072
Moqtik Bawase, M R Saraf
Abstract Utilization of higher ethanol blends, 20% ethanol in gasoline (E20), as an alternate fuel can provide apparent benefits like higher octane number leading to improved anti-knocking properties, higher oxygen content resulting in complete combustion. Apart from technical benefits, use of ethanol blends offer certain widespread socioeconomic benefits including option of renewable source of energy, value addition to agriculture feedstock resulting in increase in farm income, creation of more jobs in rural sector and creating job at local levels. Use of higher blends of ethanol can reduce dependence on foreign crude leading to substantial savings in cost of petroleum import. The impact of higher Gasoline-Ethanol blend (E20), on the fuel system components of gasoline vehicles must be known for assessment of whether the fuel system will be able to perform as intended for the complete design life of the system.
2017-01-10
Technical Paper
2017-26-0110
Lasse Moklegaard, Amitabh Saran
Abstract Truck and car manufacturers are required to satisfy certain emission standards while driving regulatory prescribed driving cycles on a vehicle chassis dynamometer. In India, the requirement is to use the regulatory Modified Indian Driving Cycle (MIDC), derived from the European Driving Cycle. The MIDC is a modal driving cycle with protracted periods at constant speed and uniform acceleration and deceleration patterns. It does not emulate typical road driving. In this study we instrument vehicles with off-the-shelf On-Board-Diagnostics (OBD) loggers to record actual drive data. The recorded vehicle speed profiles are then used as inputs for the vehicle simulation model we develop. The simulation model uses vehicle speed as an input and then calculates power required at the wheel, gear box, and Internal Combustion Engine (ICE) for the vehicle to achieve the measured speed profile. We use Willans Approximation to model the ICE fuel flow based on torque and speed.
2017-01-10
Technical Paper
2017-26-0107
Monanshi Gupta, Yasser Rafat, M. Saad Alam
Abstract Electric vehicles (EVs) are considered as zero emission vehicles because of no exhaust emissions (tailpipe emission). But electric power generation contributes in the well to wheel emissions. Hence, Electric vehicle cannot be regarded as completely pollution free. In Internal Combustion Engine (ICE) based vehicles, the pollution is from both the tailpipe (exhaust pipe) and from the well to wheel (extraction of the gasoline in this case). Tailpipe emissions are taken in compliance with Bharat stage emission standards. Standard emissions of CO2, NOx, PM and CH from refineries, during extraction of fuel (gasoline/diesel), are considered for well to wheel emissions. In this work a comparative study of tailpipe and well to wheel emissions from EVs and ICE vehicles is carried out. Three vehicle categories namely; Heavy Duty Vehicles, Passenger cars and 2 wheelers and four major pollutants, namely; CO2, NOx, PM and CH (hydrocarbons) are taken into consideration.
2017-01-10
Technical Paper
2017-26-0117
Matti A Harkonen, Alok Trigunayat, Arvind Kumar, Bosco Rajan
Abstract Light Duty Vehicles (LDVs), typically with engine displacement volume of less than 1.5L are an integral part of the India’s automobile sector as they are one of the most preferred means of transportation in rural as well as urban India. This market has always been on the rise as a result of rising population, growing commercialization, increasing commercial activities, etc. which are all contributing to the increased demand for intra city transportation. The passenger LDVs such as the three wheeler segment dominates the market as the need for affordable passenger commutation is higher than the need for goods carriage within a city. With BS VI norms slated to be implemented in 2020, it becomes imperative to understand, plan and work out strategies to meet these norms effectively on the Indian roads & actual Indian driving behavior, especially for these LDVs.
2017-01-10
Technical Paper
2017-26-0132
Abhilash Jain, Jyotirmoy Barman, Kumar Patchappalam, Srikanth Gedela
Abstract Selective Catalytic Reduction has established itself to significantly reduce NOx emissions from diesel engines. Typically, in this technology, aqueous urea solution is injected into hot exhaust stream which chemically decomposes to form ammonia and then reacts with NOx to form safe byproducts as H2O and N2 over the catalyst surface. However, incomplete thermal decomposition of urea not only reduces the NOx conversion efficiency and increases the ammonia slip, but also leads to the formation of solid crystals that adversely affect the performance of the system by increasing the back pressure and lowering the overall fuel economy. The present study discusses about the main reasons that lead to crystal formation in a vanadium based SCR system on a six cylinder 5.6l diesel engine and also design considerations of decomposition tube that affect the formation of crystals and ways to mitigate them.
2017-01-10
Technical Paper
2017-26-0127
Antoine Lacarriere, Thierry Seguelong, David Spivey, Ashish DAS
Abstract India is moving to Bharat Stage VI (BS-VI) from 2019 significantly lowering particulate mass (PM) , particle number (PN) and Nitrogen Oxides NOx emissions limits, as well as Carbon Dioxide CO2. BSVI’s particulate limits will require the use of diesel particulate filters (DPFs), which will need to operate properly under the driving conditions prevalent in India. Furthermore, NOx and CO2 emissions control will include advanced combustion modes with advanced fuel injectiontechnologies based on high pressure fuel injection and smaller injector holes, in combination with active NOx reduction measures. These advanced technologies will increase sensitivity to fuel quality, so will require tighter control of sulfur content, water contamination, fuel stability, lubricity and corrosion. These are real challenges for the robustness and durability of strategies developed for BS-VI and beyond.
2017-01-10
Technical Paper
2017-26-0137
Marco Schöggl, Ernst-Georg Lorinser
Abstract With the official publication of the “RDE package 1” on 31st March 2016 the long awaited start of RDE testing is now fixed. This event marks a milestone in the emission legislation for passenger cars and is the first of a series of four RDE packages to fade-in real world testing of passenger cars in Europe. During the same time India announced in the Gazette of India on 19th February, 2016 - G.S.R. 187(E). - the draft of introduction of Bharat VI by April 1st 2020 [5] which also should include the Real Driving Emissions (RDE) on-road certification as per procedure laid down in AIS137 and as amended from time to time. As European RDE legislation will be the baseline for Indian RDE legislation rules this paper will highlight the differences and challenges expected between the requirements in Europe compared to India during the first tests done by AVL Technical Center Private Limited located in Gurgaon.
2017-01-10
Technical Paper
2017-26-0133
Ashok Kumar, Junhui Li, Jinyong Luo, Saurabh Joshi, Aleksey Yezerets, Krishna Kamasamudram, Niklas Schmidt, Khyati Pandya, Prachetas Kale, Thangaraj Mathuraiveeran
Abstract Advanced emission control systems for diesel engines usually include a combination of Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF), Selective Catalytic Reduction (SCR), and Ammonia Slip Catalyst (ASC). The performance of these catalysts individually, and of the aftertreatment system overall, is negatively affected by the presence of oxides of sulfur, originating from fuel and lubricant. In this paper, we illustrated some key aspects of sulfur interactions with the most commonly used types of catalysts in advanced aftertreatment systems. In particular, DOC can oxidize SO2 to SO3, collectively referred to as SOx, and store these sulfur containing species. The key functions of a DOC, such as the ability to oxidize NO and HC, are degraded upon SOx poisoning. The impact of sulfur poisoning on the catalytic functions of a DPF is qualitatively similar to DOC.
2017-01-10
Technical Paper
2017-26-0120
Kevin Hallstrom, Sandip D. Shah
Abstract The legislative decision to accelerate the implementation of regulations requiring advanced emissions control in India have accelerated the need to advanced emissions control systems. Particulate filters and NOx abatement technology will be needed to meet the new BSVI standards. Integration of these emission control technologies into engine design poses new challenges to the Indian Heavy Duty Diesel Truck Industry. Each new market that implements advanced emission regulations faces challenges that are unique to the local regulation, the local vehicle design, and the local operating conditions. This paper will review the technology options available for BSVI, their strengths and weaknesses, and potential system designs. Additionally this paper will review how critical design factors such as filter regeneration conditions, duty cycle temperatures, and urea injection can affect the system design and catalyst selection.
2017-01-10
Technical Paper
2017-26-0118
Satoshi Sumiya, David Bergeal, Kenan Sager
Abstract The Indian government has announced that India will skip BS V legislation and move to BS VI from 2020. In order to meet this NOx emission standard, most vehicles will need to adopt either NOx Storage Catalyst (NSC) or Selective Catalytic Reduction (SCR). It is shown that these two devices have different NOx reduction temperature windows and different sulfur tolerance. In the LDD application, it is highly important to deal with NOx in the low temperature region directly after a cold start. NSC works in this region with better performance than SCR, but its sulfur tolerance is weaker than SCR. To improve the weakness in low temperature NOx control on SCR, SCRF® which is SCR coated Diesel Particulate Filter (DPF) was developed and it demonstrated an advantage in light-off performance, due to the advantage in temperature conditions, by minimizing heat loss upstream of the SCR device.
2017-01-10
Technical Paper
2017-26-0125
Sougato Chatterjee, Mojghan Naseri, Jianquan Li
Abstract The next generation advanced emission regulations have been proposed for the Indian heavy duty automotive industry for implementation from 2020. These BS VI emission regulations will require both advanced NOx control as well as advanced PM (Particulate Matter) control along with Particle Number limitations. This will require implementation of full DPF (Diesel Particulate Filter) and simultaneous NOx control using SCR technologies. DPF technologies have already been successfully implemented in Euro VI and US 10 HDD systems. These systems use low temperature NO2 based passive DPF regeneration as well as high temperature oxygen based active DPF regeneration. Effective DPF and DOC designs are essential to enable successful DPF regeneration (minimize soot loading in the DPF) while operating HDD vehicles under transient conditions. DOC designs are optimized to oxidize engine out NO into NO2, which helps with passive DPF regeneration.
2017-01-10
Technical Paper
2017-26-0126
Steve Golden, Zahra Nazarpoor, Ru-Fen Liu
Abstract In the context of evolving market conditions, the three-way catalyst (TWC) design is entering an exciting new phase. It remains the main emission control strategy for gasoline powered vehicles in the broad context of evolving engine technology; the move to more real-world, transient testing and much tighter tailpipe emissions regulations. The specific context here is the launch of BSVI regulations for gasoline passenger cars in India. The key approach described here is to achieve highly beneficial emission performance based on low PGM levels with the emphasis on new materials technology to significantly alter the functional balance between PGM and “promoters”. We will focus on the design of materials with the spinel structure and have developed catalyst products that synergize low levels of PGM (so-called SPGM) leveraging the key properties of the advanced spinel oxides.
2017-01-10
Technical Paper
2017-26-0123
Fabien Ocampo, Naotaka Ohtake, Barry W. L. Southward
Abstract In order to achieve NOx tailpipe targets of current diesel regulation standards two main catalytic technologies have been employed, specifically NH3-SCR and LNT. However both of these technologies face challenges with the implementation of newer / colder test cycles such as “Real Driving Emissions” (RDE), combined with CO2 targets (95 g/km is 2020 target in Europe). These cycles will require higher NOx Storage Capacity (NSC) in the low temperature region (120-350°C). Conversely, lean-burn Gasoline vehicles, with their higher operational temperatures, will require improved NSC over a broader temperature range (200-500°C). Therefore, the development of NSC materials to meet these opposing requirements is an area of extensive study by Original Equipment Manufacturers (OEMs), washcoaters, and raw materials suppliers. Today, ceria is a key component in the formulation of active NSC washcoats.
2017-01-10
Technical Paper
2017-26-0124
Vikram Betageri, R Mahesh
Abstract BS VI or Euro VI Norms mandates the RDE emission compliance for the diesel commercial vehicles. Development of the engine- after treatment system for meeting these requirements needs a greater insight into the emission behavior of the vehicle under current norms i.e. BS IV and Euro V. In other words, quantifying the on road emission of current vehicle will be helpful in developing engine/vehicle for RDE emission compliance. In the current study, the focus is on the assessment of real road NOx emission of a BS IV and Euro V complaint diesel commercial vehicle. The real road emissions of vehicle have been quantified using the onboard NOx sensor mounted on the after treatment system outlet along with a validated exhaust gas model developed and parameterized in engine control unit. The real road NOx emissions were compared with the test bench emissions for various conditions.
2017-01-10
Technical Paper
2017-26-0147
Stefan Lueckenbach, Uwe Moser, Bernd Haake, Johannes Frank
Abstract The decision to leapfrog from the Bharat Stage (BS) IV emission standards directly to the BS VI standards not only effects passenger and commercial vehicles but also India’s by far largest vehicle class, with regards to sales and production, the two-wheelers. The BS VI norm will not only tighten the emission standards, but it will also increase the required emission mileage level and upgrade the On-Board Diagnostic (OBD) requirements, also by introducing In-Use Monitor Performance Ratio (IUMPR) standards. While OBD was already introduced for passenger and commercial vehicles with BS IV in 2010, OBD will be then newly introduced for two-wheelers.
2017-01-10
Technical Paper
2017-26-0144
Dominik Lamotte, Peter Neumann, Klaus Schrewe
Abstract Emissions of diesel engine are considered to be harmful to health especially particulate emissions. Therefore, the introduction of diesel particulate filters (DPF) were successively forced by government due to reducing the emission limits to a level where inner engine measures are not sufficient anymore. To limit additional fuel consumption by increasing backpressure over the DPF, the collected soot has to be regenerated continuously or discrete by active regeneration. Active regeneration is usually realized by injecting additional fuel either due to the engines injection system into the combustion chamber (late post injection) or via an additional fuel injection device in the exhaust line. This enables increasing exhaust temperature and / or an exothermic reaction in the diesel oxidation catalyst (DOC) of the aftertreatment system.
2017-01-10
Technical Paper
2017-26-0284
Anand Subramaniam, Ravindra Shah, Swapnil Ghugal, Ujjwala Shailesh Karle, Anand Deshpande
Abstract On-board diagnostics (OBD) is a term referring to a vehicle's self-diagnostic and reporting capability. It is a system originally designed to reduce emissions by monitoring the performance of major emission related components. There are two kinds of on-board diagnostic systems: OBD-I and OBD-II. In India OBD I was implemented from April 2010 for BS IV vehicles. OBD II was implemented from April 2013 for BS IV vehicles. Apart from the comprehensive component monitors, OBD II system also has noncontinuous monitors like Catalyst monitoring, Lambda monitoring, and other after treatment system monitors. For OBD II verification and Validation, it is required to test all the sensors and actuators that are present in the engine, for all possible failures. From an emissions point of view there are lists of critical failures that are caused due to malfunction of sensors and actuators.
2017-01-10
Technical Paper
2017-26-0128
Om Parkash Bhardwaj, Ketan Krishnamurthy, David Blanco-Rodriguez, Bastian Holderbaum, Thomas Körfer
Abstract Despite the trend in increased prosperity, the Indian automotive market, which is traditionally dominated by highly cost-oriented producion, is very sensitive to the price of fuels and vehicles. Due to these very specific market demands, the U-LCV (ultra-light commercial vehicle) segment with single cylinder natural aspirated Diesel engines (typical sub 650 cc displacement) is gaining immense popularity in the recent years. By moving to 2016, with the announcement of leapfrogging directly to Bharat Stage VI (BS VI) emission legislation in India, and in addition to the mandatory application of Diesel particle filters (DPF), there will be a need to implement effective NOx aftertreament systems. Due to the very low power-to-weight ratio of these particular applications, the engine operation takes place under full load conditions in a significant portion of the test cycle.
2017-01-10
Journal Article
2017-26-0364
Igor Gritsuk, Vladimir Volkov, Vasyl Mateichyk, Yurii Gutarevych, Mykola Tsiuman, Nataliia Goridko
Abstract The article suggests the results of experimental and theoretical studies of the engine heating system with a phase-transitional thermal accumulator when the vehicle is in motion in a driving cycle. The aim of the study is to evaluate the efficiency of the vehicle heating system within thermal accumulator and catalytic converter under operating conditions. The peculiarity of the presented system is that it uses thermal energy of exhaust gases to accumulate energy during engine operation. The article describes the methodology to evaluate vehicle fuel consumption and emission in the driving cycle according to the UNECE Regulation № 83-05. The methodology takes into account the environmental parameters, road conditions, the design parameters of the vehicle, the modes of its motion, thermal state of the engine cooling system and the catalytic converter.
2017-01-10
Journal Article
2017-26-0142
Zahra Nazarpoor, Steve Golden, Ru-Fen Liu
Abstract Stricter regulatory standards are continuously adopted worldwide to control heavy duty emissions, and at the same time, fuel economy requirements have significantly lowered exhaust temperatures. The net result is a significant increase in Precious Group Metal (PGM) usage with current Diesel Oxidation Catalyst (DOC) technology. Therefore, the design and development of advanced DOC with ultra-low PGM to achieve highly beneficial emission performance improvement is necessary. The advanced DOC is synergized PGM (SPGM) with Mixed Metal Oxide (MMO). The presence of MMO in SPGM is responsible for NO oxidation to NO2 which is critical for the passive regeneration of the downstream filter and SCR function. This paper outlines the development of MMO for application in modern DOCs and addresses some specific challenges underlying this application.
2017-01-10
Journal Article
2017-26-0116
Mahesh Govindareddy, Achim Heibel
Abstract With Bharat Stage VI (BSVI) regulations on the horizon [3],[4]tighter particulate matter (PM) regulations will require the use of wall flow diesel particulate filters for on-road heavy duty (HD) diesel engines in India. The Indian HD vehicle market is very cost sensitive, especially with the majority of engine displacement being less than 7L [5] therefore, after treatment cost plays a significant role in design of the system. Robust wall flow diesel particulate filter solutions with the ability to deliver high filtration requirements required for particle number regulations can be designed in a cost-efficient manner. In this paper advanced design for diesel particulate filters with pressure drop, ash capacity, regeneration, and filtration performance are discussed. Corning’s asymmetric cell technology (ACT) was created to improve ash capacity and reduce pressure drop and has the potential to downsize up to 45%.
2017-01-10
Journal Article
2017-26-0056
Suramya Naik, David Johnson, Laurence Fromm, John Koszewnik, Fabien Redon, Gerhard Regner, Neerav Abani
Abstract The government of India has decided to implement Bharat Stage VI (BS-VI) emissions standards from April 2020. This requires OEMs to equip their diesel engines with costly after-treatment, EGR systems and higher rail pressure fuel systems. By one estimate, BS-VI engines are expected to be 15 to 20% more expensive than BS-IV engines, while also suffering with 2 to 3 % lower fuel economy. OEMs are looking for solutions to meet the BS-VI emissions standards while still keeping the upfront and operating costs low enough for their products to attract customers; however traditional engine technologies seem to have exhausted the possibilities. Fuel economy improvement technologies applied to traditional 4-stroke engines bring small benefits with large cost penalties. One promising solution to meet both current, and future, emissions standards with much improved fuel economy at lower cost is the Opposed Piston (OP) engine.
2017-01-10
Journal Article
2017-26-0073
B Ashok, K Nantha Gopal, Thundil Karuppa Raj Rajagopal, Sushrut Alagiasingam, Suryakumar Appu, Aravind Murugan
Abstract With the alarming increase in vehicular population, there is depletion of fossil fuel availability. Hence to overcome the difficulties, alternative fuels are tested and used in parts of the world. One of the difficulties with usage of alternate fuels is their high viscosity in comparison to fossil fuels. To overcome this, preheating of biofuel is a good option as it makes the fuel less viscous. In our research, we have used a helical coil heat exchanger to preheat the inlet fuel using the engine’s exhaust gas, making the system more sustainable since no external energy is used. In order to evaluate the effectiveness of preheating device a simulation study has been carried for the ethanol based biofuels. For simulation work, a set of boundary conditions has been arrived based on the experimental analysis. The results from the experiment such as velocity of air and fuel inlet were utilized as input for simulation work.
2017-01-10
Journal Article
2017-26-0074
Jayakrishnan Krishnan Unni, Divesh Bhatia, Viresh Dutta, Lalit Mohan Das, Srinivas Jilakara, GP Subash
Abstract Air pollution caused by vehicular tail pipe emissions has become a matter of grave concern in major cities of the world. Hydrogen, a carbon free fuel is a clean burning fuel with only concern being oxides of nitrogen (NOx) formed. The present study focuses on the development of a hydrogen powered multi-cylinder engine with low NOx emissions. The NOx emissions were reduced using a combination of an in-cylinder control strategy viz. Exhaust Gas Recirculation (EGR) and an after treatment method using hydrogen as a NOx reductant. In the present study, the low speed torque of the hydrogen engine was improved by 38.46% from 65 Nm to 90 Nm @ 1200 rpm by operating at an equivalence of 0.64. The higher equivalence ratio operation compared to the conventional low equivalence ratio operation lead to an increase in the torque generated but increased NOx as well.
2017-01-10
Journal Article
2017-26-0053
Sumit Rawat, Kumar Patchappalam, Abhijit Sahare
Abstract BSIV implementation for commercial vehicle in pans India effectively from April 2017. It’s very challenging job for performance and emission engineer to meet engine performance & fuel economy with stringent emission norms for high power and torque density HD diesel engine. In Altitude, lack of air availability & combustion energy passes by mechanical waste gate, lead to lower boost at partial load in waste gate region; which in turn leads to poor engine performance & fuel efficiency and higher turbo speed. To control the turbocharger design speed limit various methodologies adopted like engine derating or optimizing the combustion parameters leads to poor vehicle performance. Combustion parameter optimsation is having limited scope for turbocharger speed control.
2017-01-10
Journal Article
2017-26-0143
Saroj Pradhan, Arvind Thiruvengadam, Pragalath Thiruvengadam, Berk Demirgok, Marc Besch, Daniel Carder, Bharadwaj Sathiamoorthy
Abstract Three-way catalyst equipped stoichiometric natural gas vehicles have proven to be an effective alternative fuel strategy that has shown superior low NOx benefits in comparison to diesels equipped with SCR. However, recent studies have shown the TWC activity to contribute to high levels of tailpipe ammonia emissions. Although a non-regulated pollutant, ammonia is a potent pre-cursor to ambient secondary PM formation. Ammonia (NH3) is an inevitable catalytic byproduct of TWCduring that results also corresponds to lowest NOx emissions. The main objective of the study is to develop a passive SCR based NH3 reduction strategy that results in an overall reduction of NH3 as well as NOx emissions from a stoichiometric spark ignited natural gas engine. The study investigated the characteristics of Fe-based and Cu-based zeolite SCR catalysts in storage, and desorption of ammonia at high exhaust temperature conditions, that are typical of stoichiometric natural gas engines.
2017-01-10
Journal Article
2017-26-0138
B Sakthivel, R Sridhar, Subin Ansh, B Srinivasan, J Suresh Kumar
Abstract The air pollution is increasing at an alarming rate now a day mainly due to emissions coming out of automotive vehicles. The exhaust emissions gases are hazardous to human health. The increased number of vehicles on road will make the scenario even worse. In order to control the pollution level, the regulatory bodies are now implementing stringent emission norms. In India, the regulatory authorities has framed the transition of BS IV to BS VI emission norms in 2020 by skipping the BS V emission norms which makes the automotive industries to work on more advanced fuel management technologies. It is more tedious to control the tail pipe emissions beyond BS IV emission norms with the conventional carburetor system since it is operating on open loop system.
2017-01-10
Journal Article
2017-26-0121
Grigorios C. Koltsakis, Ioannis Kandylas, Vaibhav Gulakhe
Abstract Modern ‘DOC-cDPF’ systems for diesel exhaust are employing Pt-, Pd- as well as Pt/Pd alloy- based coatings to ensure high conversion efficiency of CO, HC even at low temperatures. Depending on the target application, these coatings should be also optimized towards NO2 generation which is involved in low temperature soot oxidation as well as in SCR-based deNOx. Zeolite materials are also frequently used to control cold-start HC emissions. Considering the wide variety of vehicles, engines and emission targets, there is no single optimum coating technology. The main target is therefore to maximize synergies rather than to optimize single components. At the same time, the system designer has nowadays a wide range of technologies to choose from, including PGM alloyed combinations (Pt/Pd), multiple layers and zones applicable to both DOCs and DPFs.
2017-01-10
Journal Article
2017-26-0119
Ragupathi Soundara Rajan, Vijay Sharma, Ashraf Emran, Devising Rathod, John Henry Kwee, Thorsten Michaelis-Hauswaldt, Thomas Körfer
Abstract The emission legislations are becoming increasingly strict all over the world and India too has taken a big leap in this direction by signaling the migration from Bharat Stage 4 (BS 4) to BS 6 in the year 2020. This decision by the Indian government has provided the Indian automotive industry a new challenge to find the most optimal solution for this migration, with the existing BS 4 engines available in their portfolio. Indian market for the LCV segment is highly competitive and cost sensitive where the overall vehicle operation cost (vehicle cost + fluid consumption cost) is the most critical factor. The engine and after-treatment technology for BS 6 emission levels should consider the factors of minimizing the additional hardware cost as well as improving the fuel efficiency. Often both of which are inversely proportional. The presented study involves the optimization of after treatment component size, layout and various systems for NOx and PM reduction.
2017-01-10
Journal Article
2017-26-0113
Azael J. Capetillo, Fernando Ibarra, Dominik Stepniewski, Jo Vankan
Abstract Selective catalytic reduction (SCR) systems have become the preferred technology to deal with NOx emissions in Diesel engines. Their efficiency is highly reliant, among other factors, on the uniformity of distribution - known as Uniformity Index (UI) - of NH3 which is injected into the system through a urea-water solution (UWS). SCR system make use of a mixer component designed to achieve the desired UI levels. However, the great variety of exhaust systems, makes it impossible to employ a universal solution. Therefore, each SCR system requires of a tailor made mixer, capable of achieving the required UI, while preventing urea crystallisation and minimising pressure drops. Computer fluid dynamics (CFD) tools together with optimisation techniques based on the design of experiments (DoE) can be used to obtain the appropriate mixer design.
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