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Technical Paper
2014-10-13
Juan J. Hernández, Rosario Ballesteros, Javier Barba, José Guillén-Flores
In order to reduce the pollutant emissions (mainly NOx and PM) of diesel engines, the addition of small gaseous fuel amounts (such as natural gas, biogas, reforming gas, LPG) or dual mode operation (in which a pilot injection of diesel fuel promotes the gaseous fuel combustion) have been proved as potential techniques. This paper is focused on a detailed characterization of the particles emitted from a single cylinder diesel engine when part of the reference diesel fuel (10 and 20% by energy) is replaced by a gaseous fuel (producer gas, mainly composed by H2, CO and CH4) coming from biomass steam gasification (renewable fuel which has not been previously analyzed when used in diesel engines). The engine was operated at constant speed and torque, varying the EGR rate (0 and 15%). Particle samples were collected by means of fiber glass filters placed in a dilution mini-tunnel for both to determine the particle mass and for further characterization. Simultaneously, during tests, part of the exhaust gas was conducted to a system formed by two diluters and a SMPS (Scanning Mobility Particle Sizer) to obtain the particle size distribution.
Technical Paper
2014-10-13
Maria Bogarra, Angel Ramos, Daniel Fennell, Jose Herreros, Andrew York, Paul Millington, Athanasios Tsolakis
Over last few years gasoline direct injection (GDI) engines have become popular in high performance transportation vehicles due to several attractive advantages (e.g. fuel economy, improved power, downsizing, knock resistance, reduced gaseous emissions) over preceding engine technologies (e.g. port injection). GDI engines however are associated with high levels of particulate matter (PM) emissions, which is a major concern on account of the new emission legislation. Thus, this research work is focused on the possible advantages that on-board hydrogen production in the exhaust gas fuel reforming process can offer on PM emissions from the GDI combustion. The potential benefits of reformate, a rich hydrogen gas, on different components of PM emissions (soot and organic material) under different injection strategies. On the other hand, it is well-known the uncertainties related to the measurement of particulates due to the different phenomena occurring in the exhaust pipe (e.g. collision, agglomeration, etc.), sampling lines and dilution system (e.g. adsorption, condensation and nucleation of hydrocarbons) which modify the nature and/or alter the characteristics of particulates formed in the combustion chamber.
Technical Paper
2014-10-13
Matthew McAllister, Stephen Smith, Paul Kapus, Khai Vidmar, Alexander Hochnetz
This paper describes the findings of a design, simulation and test study into how to reduce particulate number (Pn) emissions in order to meet EU6c legislative limits. The objective of the study was to evaluate the Pn potential of a modern 6-cylinder engine with respect to hardware and calibration when fitted to a full size SUV. Having understood this capability, the combustion system was redesigned and the calibration was optimised in order to meet an engineering target Pn value of 3x1011 in the NEDC drive cycle. Extensive design and CFD work was conducted to refine the inlet port, piston crown and injector spray pattern in order to reduce surface wetting and improve air to fuel mixing homogeneity. The design and CFD steps are reported within this paper along with the results compared to target. The ECU software was optimised in order to allow for calibration strategies leading to minimised wall interaction of injected fuel. The Pn optimisation by calibration measures with the improved combustion system followed a specific development process.
Technical Paper
2014-10-13
Christoph Menne, Simon Galbraith, Alan Jones, Lars Henning, Thomas koerfer
In September 2013 the Jaguar XF 2.2l ECO sport brake and saloon were introduced to the European market. They are the first Jaguar vehicles to realize CO2 emissions below 130 g/km. To achieve the significantly reduced fuel consumption values with an existing 2.2l I4 Diesel engine architecture selected air path and fuel path components were optimized for increased engine efficiency. Hardware selection and development in the available short time frame were only enabled by the consequent utilization of the most advanced CAE tools throughout the design phase but also during the complete vehicle application process. Changes to the base engine architecture were ruled out at the beginning of the project due to the implications on manufacturing complexity and the limited given time frame for realization. To allow a fuel consumption reduction of more than 10% vs. the first introduction of the 2.2l I4 Diesel in XF the following measures were identified: - Improved combustion efficiency due to more advanced centre of combustion for most engine operating points - Improved fuel spray and mixture preparation - Air path with reduced pressure losses especially for the high pressure exhaust gas recirculation - significantly enhanced cooling performance of the high pressure exhaust recirculation path - downspeeding with advanced transmission control The potential of the listed measures and their interactions, the chosen hardware components and the used development and application methodologies shall be presented in this paper.
Technical Paper
2014-10-13
Kihyung Joo, Jin Woo Park, Jin-ha Lee, Seok-Jae Kim, Seungbeom Yoo
In diesel engine development, the new technology is coming out to meet the stringent exhaust emission regulation. The regulation demands more eco-friendly vehicles. Euro6c demands to meet not only WLTP mode, but also RDE(Real Driving Emission). In order to satisfy RDE mode, the new technology to reduce emissions should cover all operating areas including High Load & High Speed. It is a big challenge to reduce NOx on the RDE mode and a lot of DeNOx technologies are being developed. So the new DeNOx technology is needed to cover widened operating area and strict acceleration/deacceleration. The existing LNT(Lean NOx Trap) and Urea SCR(Selective Catalytic Reduction) is necessary to meet the typical NEDC or WLTP, but the RDE mode demands the powerful DeNOx technology. Therefore, the LNT & Urea SCR on DPF was developed through this study. This complex new technology consists of new catalysts(to reduce emissions), insulation(to improve fuel economy, and catalytic performance) , and logical controller(to control DeNOx and DePM strategy).
Technical Paper
2014-10-13
Aayush Mehrotra, Simhachalam Juttu, Siva Subramanian Ravishankar, Ghodke Pundlik Rambhaji
Cooling EGR & improving its mixing with air has given consistent improvement in diesel emissions, hence the evolution of superior cooling technologies & low pressure EGR helps in meeting stringent diesel emission norms. For the same volume of exhaust gas, cooled exhaust gas occupies lower volume for the same mass; thereby it is possible for engine to digest more amount of EGR or air depending upon the trade off and substantially improve the heat carrying capacity of exhaust gas. Lowering the temperature of EGR gives a great potential in reducing NOx and smoke in diesel engines, it helps in lowering the EGR mixture temperature and hence reducing the in cylinder temperature. An attempt has been made here to lower the EGR temperature downstream of a conventional cooler without changing the cooler design itself. For this, the source for coolant has been taken from radiator outlet unlike the conventional location of cylinder block. A 12 V electric pump circulates coolant to EGR cooler with a bypass from radiator; since the radiator outlet is much cooler than cylinder block outlet the cooling efficiency increases significantly.
Technical Paper
2014-10-13
Andrew Pedlow, Geoffrey McCullough, Alexandre Goguet, Ken Hansen
Pedlow, A1). McCullough1), G. Goguet, A2). 1) School of Mechanical and Aerospace Engineering, Queen's University Belfast 2) School of Chemistry and Chemical Engineering, Queen's University Belfast Pedlow, A. Email: apedlow01@qub.ac.uk, Tel.: +4428 9097 4569 Mathematical modelling has become an essential tool in the design of modern catalytic systems. Emissions legislation is becoming increasingly stringent, meaning that mathematical models of after-treatment systems must become more accurate in order to provide confidence that a catalyst will convert pollutants over the required range of conditions in order to meet legislated limits. Automotive Catalytic converter models contain several sub-models that represent processes such as mass and heat transfer, and the rates at which the reactions proceed on the surface of the precious metal. Of these sub-models, the prediction of the surface reaction rates is by far the most challenging due to the complexity of the reaction system and the large number of gas species involved.
Technical Paper
2014-10-13
Lubomir Miklanek, Ondrej Gotfryd
Diesel fuel-operated heaters (FOH) are generally used as an independent heat source for any system in which a diesel fuel and a battery power is available. Based on the fact that future engines will become even more efficient and thus less waste heat will be available to heat the passenger compartment, independent heat sources will be even more necessary. Current emission limits for diesel FOHs in Europe are not strict as the engine emission limits. There are only limited exhaust emissions at steady-state operating regimes, not at the both cold-starts and switching-off regimes. However, it can be assumed that these emission limits will be more strict with increasing number of independent FOHs. Thus exhaust emissions at the both cold-starts and switching-off regimes will be also established. Increased emissions of CO, HC and also smoke (especially white smoke emissions) appears at the both cold-starts and switching-off regimes in case of a conventional design of FOHs. The emission limits for steady-state regimes can be exceeded several times at these two unsteady regimes.
Technical Paper
2014-10-13
Luke Aubrey William Blades, Roy Douglas, Geoffrey McCullough, Jonathan Stewart, Andrew Woods
Regulations concerning automotive exhaust emissions are becoming more and more stringent, making it necessary for the development of more efficient and resistant catalytic control systems. The three-way catalytic converter acts to reduce these emissions by performing simultaneous oxidation of carbon monoxide (CO) and hydrocarbons (HC) and reduction of oxides of nitrogen (NOx). Conversion of these harmful gases by exothermic reactions leads to high temperatures within the catalytic converter, causing catalyst ageing due to thermal deactivation. At high temperatures the precious metal particles agglomerate, decreasing the surface area of catalytic sites and therefore reducing catalyst activity. Catalyst deactivation can be shown by a shift of light-off temperature. With the increasing complexity of modern automotive after-treatment systems, and the slow and expensive nature of testing and ageing catalyst samples on-road, much more rapid laboratory test methods must be considered. The accelerated thermal ageing of cored catalyst samples was performed in a static air (oxidising) atmosphere, an ageing method which is commonly used in industry.
Technical Paper
2014-10-13
Jonathan Stewart, Roy Douglas, Alexandre Goguet, Cristina Elena Stere, Luke Blades
Kinetic models are becoming an ever present tool in the development of automotive catalysis, primarily used for characterisation of catalysts and as a predictive tool for performance. This has led to a large number of kinetic models related to automotive catalysis appearing in literature in literature in the past decades. Most kinetic models for automotive application focus primarily on the global kinetic approach for reaction kinetics, with the more chemically accurate micro-kinetics appearing more frequently in the past number of years. One of the most critical aspects in the development of a kinetic model in general is the method used to control the switch between limiting factors over the period of the chemical reaction, namely mass transfer and reaction kinetics. This balance becomes increasingly more critical with the automotive application as the gas composition and gas flow vary throughout the automotive cycles resulting in a large number or reactions competing, with a constantly changing space velocity.
Technical Paper
2014-10-13
Kristin Götz, Anja Singer, Olaf Schröder, Christoph Pabst, Axel Munack, Jürgen Bünger, Juergen Krahl
The political and economic major aim in Europe is the increase of the use of renewable energy resources up to 10 % till 2020. This means a reduction in crude oil dependency. Already well known in diesel fuel area are fatty acid methyl esters, named biodiesel. However, this biogenic component has not only advantages, as a further raise of the amount of biodiesel content in diesel fuel higher than seven percent can lead to an increase of the engine oil dilution in passenger cars with diesel particulate filters. Because of the regeneration of the particulate filters, the entry of fuel components increases. This may induce sludge formation in the engine oil. A promising approach to reduce this problem is a new type of biogenic fuel, called HVO (hydrotreated vegetable oil). This is also produced from vegetable oil or animal fat and it is chemically quite similar to fossil diesel fuel. Like biodiesel, HVO is free of sulfur or any aromatics. HVO has a higher cetane number in comparison to biodiesel and most diesel fuels.
Technical Paper
2014-10-13
Simon Reifarth, Hans-Erik Angstrom
The distribution of EGR between the cylinders of an internal combustion engine has been shown to have large impact on the engine emissions. Especially at high EGR, the combustion reacts sensibly to variations in the EGR-rate. A cylinder that receives excessive EGR produces soot particles while a cylinder with too little EGR has increased NOx-emission. It is therefore important to have knowledge about the mixing in an engine. This study compares two different EGR-mixing measurement methods. The first is based on CO2 measurement with standard probes, placed at 36 different locations in the intake manifold of the engine. The second method uses a laser beam and a detector to gain information about the mixing with a high time-resolution, placed at six positions of the intake manifold. Additionally, 1-D simulations are used to gain information about the mixing process. To vary the mixing process on the engine, two different air/EGR mixers are used and their mixing performance is evaluated.
Technical Paper
2014-10-13
Achinta Varna, Konstantinos Boulouchos, Alexander Spiteri, Panayotis Dimopoulos Eggenschwiler, Yuri M. Wright
Simulations for a pressure-assisted multi-stream injector designed for urea-dosing in a selective catalytic reduction SCR exhaust gas system have been carried out and compared to measurements taken in an optically accessible high-fidelity flow test rig. The experimental data comprises four different combinations of mass flow rate and temperature for the gas stream with unchanged injection parameters for the spray. First, a parametric study is carried out to determine the importance of various spray sub-models, including atomization, spray-wall interaction, buoyancy as well as droplet coalescence. Optimal parameters are determined using experimental data for one reference operating condition. The model is subsequently applied to all operating conditions with unaltered parameters and validated by means of the measured droplet velocity fields, droplet diameter distributions and spray-tip propagation which have been characterized by means of Particle Image Velocimetry (PIV), Phase Doppler Anemometry (PDA) and shadowgraph imaging.
Technical Paper
2014-10-13
Benjamin Kingsbury, Jonathan Stewart, Zhentao Wu, Roy Douglas, Kang Li
This study describes an innovative monolith structure designed for applications in automotive catalysis using an advanced manufacturing approach developed at Imperial College London. The production process combines extrusion with phase inversion of a ceramic-polymer-solvent mixture in order to design substrate micro-structures that offer improvements in performance, including reduced PGM loading, reduced catalyst ageing and reduced backpressure. The novel substrate is formed from hollow fibres which are fused together to form a ceramic monolith. A highly ordered micro-structure is present, formed from micro-channels which extend from the inner surface to the outer surface of the hollow fibres. The entrances to the micro-channels are in the range of 10 – 90 μm and are directly accessible to the exhaust gas as it passes along the substrate. The designed micro-structure generates a geometric surface area of 32,000 m²/m³, while at the same time achieving a 40-70 % reduction in pressure drop along the length of the substrate.
Technical Paper
2014-10-13
Xinyu Wang, Yadong Deng
Automotive exhaust-based thermoelectric generators (TEGs) effectively convert exhaust heat into electrical energy, which gradually improve utilization efficiency of the fuel. In this paper, a newly heat exchanger with the shape of regular-octagon cylinder box in TEG is designed. Through building three-dimensional models of different TEGs , it is available to calculate thermal stress field distribution of them separately in ANSYS software and test the reliability of expected TEG .By conducting multi -ordered temperature - fluid - solid coupling of heat exchanger in FLUENT software , adopting different heat exchanger structures, setting different parameters of length, width, height, thickness of the distributing fins, guiding fins, converging fins in the heat exchanger, and installing different distribution angles and spacing of these fins, the temperature field, pressure field and flow field simulation results are gained to explore the influence of air current resistance and the thermal performance of TEG caused by diverse heat exchanger structures and various physical-dimension and distribution of the fins.
Technical Paper
2014-10-13
Jon Andersson, John May, Cecile Favre, Dirk Bosteels, Simon de Vries, Matthew Heaney, Matthew Keenan, Jonathon Mansell
The exhaust emissions of two Euro 6 diesel cars with different emissions control systems have been evaluated both on the road and over various chassis dynamometer test cycles. European emissions limits are currently set using the New European Driving Cycle (NEDC), but the European Commission is preparing additional test procedures to ensure that emissions are well controlled both in real use and over the legislative test cycle. The main focus of this work on ‘Real Driving Emissions’ (RDE) is on measurements using Portable Emissions Measurement Systems (PEMS) in real, on-road driving. A key focus of a test programme undertaken for AECC (the Association for Emissions Control by Catalyst) by Ricardo was therefore the use of PEMS systems to measure on-road emissions of both gaseous pollutants and particulate matter. This included measurement of particle number emissions with a new candidate system for this type of measurement. The results from this testing are compared with emissions measured over four different chassis dynamometer test cycles – the current legislative cycle (New European Driving Cycle, NEDC); the Common Artemis suite of test cycles (CADC) that is widely used in emissions modelling; the new Worldwide Light-duty Test Cycle (WLTC) defined by the UN Working Party on Pollution and Energy (GRPE) as part of the development of the Worldwide harmonised Light vehicles Test Procedure (WLTP); and a set of cycles produced by a Random Cycle Generator based on ‘short trip’ segments from the EU database used to construct WLTC.
Technical Paper
2014-10-13
Amar Deep, Dhruv Gupta
The interest of using alternative fuels in diesel engines has been accelerated exponentially due to a foreseen scarcity in world petroleum reserves, increase in the prices of the conventional fossil fuels and restrictions on exhaust emissions such as greenhouse gases from internal combustion (IC) engines initiated by environmental concerns. The constant trade-off between efficiency and emissions should be in proper balance with the conventional fuels in a fuel design process for future combustors. Unlike gasoline and diesel, alcohols act as oxygenated fuels. Adding alcohols to petroleum products allows the fuel to combust properly due to the presence of oxygen, which enhances premixed combustion phase, improves the diffusive combustion phase which increases the combustion efficiency and reduces air pollution. The higher activation energy of alcohols leads to better resistance to engine knocking that allows higher compression ratios and greater engine thermal efficiencies. Direct use of alcohol/diesel fuel blends is one of the most interesting possibilities because of their lower viscosity and similar physio-chemical properties to mineral diesel; most importantly, prior modifications on diesel engine are not required.
Technical Paper
2014-10-13
Seyed Ali Hadavi, Hu Li
Biodiesel have attracted a growing interest worldwide. Biodiesel (Fatty Acid Methyl Ester-FAME) is currently one of the most popular biofuel for reducing greenhouse gas (GHG) emissions for road transport vehicles with in the capabilities of current engine designs. There is a clear need to explore the feasibility of maximising the carbon reduction potentials of plant and vegetable oils by using oils directly in engines with out transesterification. The fuel additives was added to UCO renewable fuel. The largest benefit of using UCO directly is the carbon reduction potentials .A Euro 5 ,11.9 litre heavy duty truck, Mercedes Benz AXOR-C 6x2 with Turbo-intercooler, in-line six cylinders ,Water cooled with electromagnetic fan, and Exhaust Stainless steel ,SCR catalytic converter was used. This study measured Regulated tailpipe exhaust Emission under real world driving condition, and compared with HDV emissions standards. An on-board FTIR (Fourier Transform Infrared) was used for exhaust emission measurement system which can measure up to 51 species with detection limits of 3 to 5 ppm and accuracy of 2% within the calibrated measurement range depending on application and compound.
Technical Paper
2014-10-13
Piotr Bielaczyc, Andrzej Szczotka, Joseph Woodburn, Ryszard Michalowski PhD
Natural gas is widely used in the refining industry of liquid transportation fuels. It is seen as a bridge to a future hydrogen-based economy. For that reason, the natural gas-powered vehicle fleet is growing in many European countries. Technology for light-duty CNG vehicles is well established, and CNG vehicles have performance comparable to their petrol-fuelled equivalents. CNG is commonly used in spark ignition engines because their powertrains are relatively easy to convert from liquid to gaseous fuels. In addition, the importance of natural gas will increase significantly as fuel for transportation. Apart from its massive availability at attractive current market prices, its particular advantages in terms of CO2 and exhaust emission have led to the increased use of natural gas as a fuel source. The aim of this paper was to determine the influence of CNG fuel on emissions in the context of the new Euro 6 emissions requirements and to compare exhaust emissions and performance of the vehicles fuelled with CNG and with petrol.
Technical Paper
2014-10-13
Andrew Smallbone, Amit Bhave, Peter Man
In this paper we combine experimental data, physics-based models and advanced numerical techniques to investigate 1) sources of friction losses in heavy-duty IC engines and, 2) fuel efficiency losses (and CO2 sources) in an engine and vehicle model over 160 ‘real-world’ and legislated drive cycles. These two applications are both typical examples where a multi-dimensional design space means that it is challenging to interpret and communicate the influence of each design parameter effectively and identify those of most importance for your chosen objective. In this paper, the authors present new methods to support a) the parameter estimation (model calibration) with respect to experimental data and, b) advanced global sensitivity analysis using a High Dimensional Model Representation (HDMR).
Technical Paper
2014-10-13
Simon Reifarth, Elias Kristensson, Jesper Borggren, Hans-Erik Angstrom
The use of EGR for NOX reduction is today a standard technology for diesel engines. The mixing of air and EGR is an important issue, especially for high-pressure EGR systems. An uneven distribution of EGR between the cylinders can lead to higher overall engine emissions when some cylinders produce more soot, others more NOX than they would with a perfectly even distribution. It is therefore important to understand the processes that control the mixing between air and EGR. The mixing is influenced by both the geometry of the mixing area and the pulsating nature of the flow. The aim of this work is to point out the high importance of the pulses present in the EGR-flow. By simulation in 1-D and 3-D as well as by a fast measurement method, it is shown that the EGR is transported in the air flow in packets. This implies that the timing between intake valve opening and the positioning of the EGR packets has a high influence of the distribution of EGR between the cylinders. The ability of 1-D and 3-D simulation to predict the behavior is evaluated.
Technical Paper
2014-10-13
HaNa Kim, Gwon Koo YEO, Moon Soon Cha, Kyung-Min Lee
With the increasingly stringent regulation of exhaust emissions, more effectively reducing cold-start emission is important. The main challenge is to reduce the cold-start emissions. Closed-coupled catalyst(CCC) provides fast light-off time by utilizing the energy in the exhaust gas. Also, it is a well-known fact that dispersion of PGM(Patinum group metal)particles effects on the catalytic activity. For the high conversion of CO and THC emissions during cold start period, the fact was confirmed that the design of deposition of high Pd in the first brick of the TWC. However, CCC occurred during engine operation and the catalyst temperature exceeds 1050˚C, the pattern Shape on the crystallinity of PGM be effected with high temperature. From two aging temperature conditions(900℃ and 1050℃), the conversion rate of THC showed different behaviors. In this work, We investigates the THC conversion rate of Pd/Rh catalysts to their aging and testing. To show the effcets of Pd distribution on two factor: one featured Zone-coating length ratio: the other, Pd deposition of Zone-coating.
Technical Paper
2014-10-13
Kohei Yoshida, Yusuke Nozaki, Toshihiro Mori, Yuki Bisaiji, Yuki haba, Kazuhiro umemoto, Takao Fukuma
To fulfill upcoming stringent worldwide CO2 emission target, engine thermal efficiency should further be increased and diesel engine is one of the promising solutions. Nevertheless to ensure good air quality, NOx emission should be reduced using a specific catalyst. In order to reduce NOx from a diesel engine operation in lean condition, Urea-Selective Catalyst Reduction (SCR) or NOx Storage and Reduction (NSR) systems have been widely adopted in the European market. The NSR system is most efficient for small/mid vehicle size since it requires less packaging space and it is less expensive than a urea SCR system. However, its NOx reduction performance is currently limited under high temperature and high space velocity conditions since the NOx storage ability as nitrate is insufficient under such conditions. For future NSR usage, it is therefore necessary to improve the NOx reduction performance of NSR. DiAir (Diesel NOx After-treatment by Adsorbed Intermediate Reductants) has been introduced as one of the measures to improve NOx conversion performance under high space velocity (SV) and temperature conditions.
Technical Paper
2014-10-13
Erkka Saukko, Panu Karjalainen, Topi Ronkko, Jorma Keskinen, Pekka Nousiainen, Liisa Pirjola
The Diesel Particulate Filter (DPF) is currently the norm of soot reduction strategy in road transportation. The filters currently in use remove virtually all of the soot mass. As the DPF loading increases the engine backpressure, the filters are regenerated using various techniques. The common denominator in these techniques is the temperature elevation needed to oxidize the captured soot from the filter with NO2 or O2. The frequency and extent of regeneration is an optimization problem for the fuel economy: regeneration uses extra energy while extending the regeneration interval increases the backpressure reducing the total fuel economy of the engine. From the standpoint of soot emission control, the DPF is better to be loaded than fresh, as the collected soot particles generally tend to increase the collection efficiency of the filter. As the energy expenditure on regenerations is also needed to minimize, the collection efficiency optimum is aligned with the regeneration energy saving need.
Technical Paper
2014-10-13
Arjun Prakash, Edward Nelson, Aaron Jones, James Macias, Matthew Hinojosa, Eugene Jimenez
Particulate mass (PM) emissions from DISI engines can be reduced via fuels technology that facilitates injector deposit clean-up. A significant drawback of DISI engines is that they can have higher particulate matter emissions than PFI gasoline engines. Soot formation in general is dependent on the air-fuel ratio, combustion chamber temperature and the chemical structure and thermo-physical properties of the fuel. In this regard, PM emissions and DISI injector deposit clean-up were studied in three identical high-selling vehicles. The tests compared the effects of a fuel (Fuel A) containing a market generic additive at lowest additive concentration (LAC) against a fuel formulated with a novel additive technology (Fuel B). The fuels compared had an anti-knock index value of 87 containing upto 10% ethanol. The vehicles were run on Fuel A for 20,000 miles followed by 5,000 miles on Fuel B using a chassis dynamometer. It was observed that Fuel A gave rise to an increase in PM emissions indicative of DISI injector deposit build-up.
Technical Paper
2014-10-13
S F Benjamin, C A Roberts
In an attempt to reduce particulate and NOx emissions from Diesel exhaust, the combined DPF and SCR filter is now frequently chosen as the preferred catalyst. When this device functions effectively it saves valuable packaging space in a passenger vehicle. As part of its development, modelling of its emissions performance is essential. Single channel modelling is the obvious choice for a DPF filter because of its complex geometry. This, however, can be computationally demanding. For a normal flow-through catalyst monolith the porous medium approach is an attractive alternative. This paper attempts to model an SCRF by applying the porous medium approach. The model is essentially 1D but as with all porous medium models, can very easily be applied to 3D cases once developed and validated. The model is described in full in this paper and values for all the key parameters are presented. The filter is assumed to collect soot in the inlet channels, but only the output channels are coated with SCR washcoat, as in the most recent devices.
Technical Paper
2014-10-13
Jing Qin, Xiang Li, Yiqiang Pei
Abstract The aim of this detailed research is to experimentally investigate the effects of ignition timings, injection timings, excess air ratio (λ) and lubricating oil on particulate matter (PM) emissions from a 2.0 L turbo-charged gasoline direct injection (T-GDI) engine fueled with gasoline, methanol/gasoline blends and pure methanol. The results of this paper show that the PM number concentration mostly presents a typical bimodal or trimodal distribution in figures. The particle number concentration mainly concentrates in the nucleation mode. With the increase of methanol volume fraction in the blended fuel, the PM emissions decrease significantly. Furthermore, there are few particles when the engine fueled with pure methanol. As advancing ignition timing, the total PM number rises by over about 200%. Under the pre-ignition condition, the higher in-cylinder temperature may also accelerate the formation of the nucleation mode particles. As advancing injection timing, PM emissions decrease first, and then increase.
Technical Paper
2014-10-13
Bhimrao Patil, Vighnesha Nayak, Mohanan Padmanabha
This work aims study on the method of NOx reduction and performance enhancement by analysis of MPFI multi-cylinder gasoline engine running on LPG using gas injection system and vaporized water methanol induction to the intake manifold. For the generation of vaporized water methanol, heat from the exhaust gas has been used. Different percentages of water methanol by mass basis were used with variable engine speed ranging from 2000 to 4500 rpm. The results showed that as the percentage water methanol induction level to the engine increased, there is slight increase in percentage of useful work, while the NOx decreased drastically about 47%. Additionally, the engine brake thermal efficiency increases. The average increase in the brake thermal efficiency for a 20% water methanol with LPG is approximately 1.5% over the use of LPG without water methanol induction.
Technical Paper
2014-10-13
Dave OudeNijeweme, Paul Freeland, Markus Behringer, Pavlos Aleiferis
Particulate emissions are of growing concern due their negative health impacts. Many urban areas around the world currently have levels exceeding the World Health Organisation safe limits. Gasoline engines, especially when equipped with direct injection systems, contribute to this pollution. In recognition of this fact European limits on particulate mass and number are being introduced. A number of ways to meet these new stringent have been under investigation at MAHLE Powertrain, with this paper focussing on the improvement potential of the injection equipment. This investigation is part of MAHLE’s ongoing particulate research and method development that includes optical engine spray and combustion visualisation, CFD method development, engine and vehicle testing with the aim to move particulate emission development upstream in the development process. As part of this work, a spark eroded and a laser drilled injector were fully characterised in a spray vessel under key engine running conditions.
Technical Paper
2014-10-13
Jonathan Stewart, Andrew Woods, Roy Douglas, Richard O’Shaughnessy
With emission legislation becoming ever more stringent, automotive companies are forced to invest heavily in solutions to meet the targets set. To date, the most effective way of treating emissions is through the use of catalytic converters. Since the introduction of these converters as the main method of reducing automotive emissions, catalyst performance testing has become a major part of automotive research and development. One of the most critical aspects of the performance testing process is catalyst ageing. Legislation has been introduced stating that catalytic converters must meet the set emissions standards legislation up to a lifetime of 150,000 miles (LEV 2014-2022). The catalytic converter will deactivate over its lifetime due to a number of different factors, such as, thermal deactivation, poisoning, fouling and structural breakdown of the catalyst. It is therefore of the utmost importance for automotive companies to evaluate the performance of the catalytic converters under these conditions.
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