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Viewing 31 to 60 of 22030
2017-10-08
Technical Paper
2017-01-2264
Hyun Woo Won, Alexandre Bouet, Joseph Kermani, Florence Duffour, Simon Dosda
Recent work has demonstrated the potential of gasoline-like fuels to reduce NOx and particulate emissions when used in compression ignition engines. In this context, low RON gasoline, a refinery stream derived from the atmospheric crude oil distillation process, has been identified as a highly valuable fuel. In addition, thanks to its higher H/C ratio and energy content compared to diesel, CO2 benefits are also expected when used in such engines. In previous studies, different Cetane Number (CN) fuels have been evaluated and a CN 35 fuel has been selected. The assessment and the choice of the required engine hardware adapted to this fuel, such as the compression ratio, bowl pattern and nozzle design have been performed on a single cylinder compression-ignition engine. The purpose of this paper is to assess different airpath and after treatment system (ATS) definitions to maximize the potential of a low-RON gasoline fuel running on a multi-cylinder compression ignition engine.
2017-10-08
Technical Paper
2017-01-2263
S. Vedharaj, R Vallinayagam, Yanzhao An, Mohammad Izadi Najafabadi, Bart Somers, Junseok Chang, Bengt Johansson
Naphtha boils in the gasoline range of 40°C to 75°C with a RON of 65, showing increased resistance to auto-ignition. It is not possible to use naphtha as a drop in fuel for CI engine and therefore, it is ideal to investigate premixed combustion of naphtha. Previous studies reports the use of naphtha in CI engine under partially premixed combustion (PPC) mode, wherein the fuel injection timing and intake air temperature controls combustion. In this study, we investigate the combustion visualization and stratification of surrogate fuel in PPC mode. The composition of naphtha surrogate is 2-methyl butane (0.21% mol), 2-methyl hexane (0.07% mol), n-pentane (0.6% mol), n-heptane (0.07% mol) and toluene (0.05% mol). Investigation of surrogate fuel in engine expands on the previous studies on surrogate fuel formation for naphtha. Based on the experimental outcome, start of injection (SOI) was found to be inversely correlated with combustion phasing during early injection timings.
2017-10-08
Technical Paper
2017-01-2265
Hao-ye Liu, Zhi Wang, Bowen Li, Shi-Jin Shuai, Jian-Xin Wang
Wide Distillation Fuel (WDF) refers to the fuels with a distillation range from initial boiling point of gasoline to final boiling point of diesel. Recent experimental results have shown WDF by blending 50% gasoline and 50% diesel (G50) exhibits much lower soot emissions than diesel at medium load with relatively low injection ratio with similar thermal efficiency. However, the engine performances fueled by G50 at both low load end and high load end are still unknown. In this study, the combustion and emission characteristics of G50 and diesel have been compared at 1600 r/min and a wide load range from 0.2 MPa IMEP to 1.4 MPa IMEP at a light-duty diesel engine. The results shown that G50 has much lower soot emissions and similar thermal efficiency compared with diesel at high load end. At 0.2 MPa IMEP, G50 exhibits high cycle-to-cycle variation and low thermal efficiency.
2017-10-08
Technical Paper
2017-01-2267
Erik Svensson, Lianhao Yin, Per Tunestal, Martin Tuner
The concept of Partially Premixed Combustion (PPC) in engines has shown to achieve very high gross indicated efficiencies, but at the expense of gas exchange efficiencies. Most of the experimental research on PPC has been conducted on compression ignition engines designed to operate on diesel fuel and relatively high exhaust temperatures. The PPC concept on the other hand relies on dilution with high exhaust gas recirculation (EGR) rates to slow down the combustion which results in low exhaust temperatures, but also high mass flows over cylinder, valves, ports and manifolds. A careful design of the gas exchange system, EGR and charge air coolers is therefore of utter importance. Experiments were performed on a heavy-duty, compression ignition engine using a fuel consisting of 80 percent 89 RON gasoline and 20 percent n-heptane. A wide range of engine speeds and loads were run using a long route EGR system.
2017-10-08
Journal Article
2017-01-2291
Sandro Gail, Takashi Nomura, Hitoshi Hayashi, Yuichiro Miura, Katsumi Yoshida, Vinod Natarajan
In emerging markets, Port Fuel Injection (PFI) technology retains a higher market share than Gasoline Direct Injection (GDI) technology. In these markets fuel quality remains a concern even despite an overall improvement in quality. Typical PFI engines are sensitive to fuel quality regardless of brand, engine architecture, or cylinder configuration. One of the well-known impacts of fuel quality on PFI engines is the formation of Intake Valve Deposits (IVD). These deposits steadily accumulate over time and can lead to a deterioration of engine performance. IVD formation mechanisms have been characterized in previous studies. However, no test is available on a state-of-the-art engine to study the impact of fuel components on IVD formation. Therefore, a proprietary engine test was developed to test several chemistries. Sixteen fuel blends were tested. The deposit formation mechanism has been studied and analysed.
2017-10-08
Technical Paper
2017-01-2287
Aniseh Abdalla, Guoyang Wang, Jun Zhang, Shi-Jin Shuai
Emission control technologies are required to achieve stringent emission regulations such as Beijing 6 (equivalent to Europe 6). In order to meet Europe 6 emission regulation, diesel oxidation catalyst (DOC) upstream of catalyzed diesel particulate filter (CDPF) with supplementary fuel injection (hydrocarbon injection (HCI)) are used for the X7 diesel engine to control the particulate matter (PM) for a heavy-duty diesel engine. This study investigated soot loading and active regeneration process in a CDPF by using secondary fuel injection in order to enhance exothermal heat which is needed to raise the CDPF temperature. The injected fuel is burnt in a DOC where the injector is mounted in the tailpipe upstream of DOC.
2017-10-08
Technical Paper
2017-01-2325
Midhat Talibi, Paul Hellier, Nicos Ladommatos
The conversion of lignocellulosic biomass to liquid fuels presents an alternative to the current production of renewable fuels for IC engines from food crops. However, realising the potential for reductions in net CO2 emissions through the utilisation of, for example, waste biomass for sustainable fuel production requires that energy and resource inputs into such processes be minimised. This work therefore investigates the combustion and emission characteristics of five intermediate platform molecules potentially derived from lignocellulosic biomass: gamma-valerolactone (GVL), methyl valerate, furfuryl alcohol, furfural and 2-methyltetrahydrofuran (MTHF). The study was conducted on a naturally aspirated, water cooled, single cylinder spark-ignition engine. Each of the platform molecules were blended with reference fossil gasoline at 20 % wt/wt.
2017-10-08
Journal Article
2017-01-2285
Eric Randolph, Raphael Gukelberger, Terrence Alger, Thomas Briggs, Christopher Chadwell, Antonio Bosquez Jr.
Abstract The primary focus of this investigation was to determine the hydrogen reformation, efficiency and knock mitigation benefits of methanol-fueled Dedicated EGR (D-EGR®) operation, when compared to other EGR types. A 2.0 L turbocharged port fuel injected engine was operated with internal EGR, high-pressure loop (HPL) EGR and D-EGR configurations. The internal, HPL-EGR, and D-EGR configurations were operated on neat methanol to demonstrate the relative benefit of D-EGR over other EGR types. The D-EGR configuration was also tested on high octane gasoline to highlight the differences to methanol. An additional sub-task of the work was to investigate the combustion response of these configurations. Methanol did not increase its H2 yield for a given D-EGR cylinder equivalence ratio, even though the H:C ratio of methanol is over twice typical gasoline.
2017-10-08
Journal Article
2017-01-2295
Ahmad Omari, Stefan Pischinger, Om Parkash Bhardwaj, Bastian Holderbaum, Jukka Nuottimäki, Markku Honkanen
Abstract The optimization study presented herein is aimed to minimize the fuel consumption and engine-out emissions using commercially available EN15940 compatible HVO (Hydrogenated Vegetable Oil) fuel. The investigations were carried out on FEV’s 3rd generation HECS (High Efficiency Combustion System) multi-cylinder engine (1.6L, 4 Cylinder, Euro 6). Using a global DOE approach, the effects of calibration parameters on efficiency and emissions were obtained and analyzed. This was followed by a global optimization procedure to obtain a dedicated calibration for HVO. The study was aiming for efficiency improvement and it was found that at lower loads, higher fractions of low pressure EGR in combination with lower fuel injection pressures were favorable. At higher loads, a combustion center advancement, increase of injection pressure and reduced pilot injection quantities were possible without exceeding the noise and NOx levels of the baseline Diesel.
2017-10-08
Journal Article
2017-01-2298
Charles S. Shanahan, S. Scott Smith, Brian D. Sears
Abstract The ubiquity of gasoline direct injection (GDI) vehicles has been rapidly increasing across the globe due to the increasing demand for fuel efficient vehicles. GDI technology offers many advantages over conventional port fuel injection (PFI) engines, such as improvements in fuel economy and higher engine power density; however, GDI technology presents unique challenges as well. GDI engines can be more susceptible to fuel injector deposits and have higher particulate emissions relative to PFI engines due to the placement of the injector inside the combustion chamber. Thus, the need for reliable test protocols to develop next generation additives to improve GDI vehicle performance is paramount. This work discloses a general test method for consistently fouling injectors in GDI vehicles and engines that can accommodate multiple vehicle/engine types, injector designs, and drive cycles, which allows for development of effective GDI fuel additives.
2017-10-08
Journal Article
2017-01-2299
Susumu Nagano, Nozomi Yokoo, Koji Kitano, Koichi Nakata
Abstract The effects of high boiling point fuel additives on deposits were investigated in a commercial turbocharged direct injection gasoline engine. It is known that high boiling point substances have a negative effect on deposits. The distillation end points of blended fuels containing these additives may be approximately 15°C higher than the base fuel (end point: 175°C). Three additives with boiling points between 190 and 196°C were examined: 4-tert-Butyltoluene (TBT), N-Methyl Aniline (NMA), and 2-Methyl-1,5-pentanediamine (MPD). Aromatics and anilines, which may be added to gasoline to increase its octane number, might have a negative effect on deposits. TBT has a benzene ring. NMA has a benzene ring and an amino group. MPD, which has no benzene ring and two amino groups, was selected for comparison with the former two additives.
2017-10-08
Technical Paper
2017-01-2378
Takayuki Ogata, Mikio Makino, Takashi Aoki, Takehide Shimoda, Kyohei Kato, Takahiko Nakatani, Koji Nagata, Claus Dieter Vogt, Yoshitaka Ito, Dominic Thier
Abstract In order to meet the challenging CO2 targets beyond 2020 despite keeping high performance engines, Gasoline Direct Injection (GDI) technology usually combined with charged aspiration is expanding in the automotive industry. While providing more efficient powertrains to reduce fuel consumption one side effect of GDI is the increased particle formation during the combustion process. For the first time for GDI from September 2014 there is a Particle Number (PN) limit in EU of 6x10 sup 12 #/km, which will be further reduced by one order of magnitude to 6x10 sup 11 #/km effective from September 2017 to be the same level as applied to Diesel engines. In addition to the PN limit of the certification cycle NEDC further certification of Real Driving Emissions (RDE) including portable PN measurements are under discussion by the European Commission. RDE test procedure requires stable and low emissions in a wide range of engine operations and durable over a distance of 160 000 km.
2017-10-08
Technical Paper
2017-01-2381
Kristian Hentelä, Ossi Kaario, Vikram Garaniya, Laurie Goldsworthy, Martti Larmi
In the present study, a new approach for modelling emissions of coke particles or cenospheres from large diesel engines using HFO (Heavy fuel oil) was studied. The model used is based on a multicomponent droplet mass transfer and properties model that uses a continuous thermodynamics approach to model the complex composition of the HFO fuel and the resulting evaporation behavior of the fuel droplets. Cenospheres are modelled as the residue left in the fuel droplets towards the end of the simulation. The mass-transfer and fuel properties models were implemented into a cylinder section model based on the Wärtsilä W20 engine in the CFD-code Star CD v.4.24. Different submodels and corresponding parameters were tuned to match experimental data of cylinder pressures available from Wärtsilä for the studied cases. The results obtained from the present model were compared to experimental results found in the literature.
2017-10-08
Technical Paper
2017-01-2383
Guoyang Wang, Jun Zhang, Bo Yang, Chuandong Li, Shi-Jin Shuai, Shi Yin, Meng Jian
Abstract Urea selective catalytic reduction (SCR) is a key technology for heavy-duty diesel engines to meet the increasingly stringent nitric oxides (NOx) emission limits of regulations. The urea water solution injection control is critical for urea SCR systems to achieve high NOx conversion efficiency while keeping the ammonia (NH3) slip at a required level. In general, an open loop control strategy is sufficient for SCR systems to satisfy Euro IV and Euro V NOx emission limits. However, for Euro VI emission regulation, advanced control strategy is essential for SCR systems due to its more tightened NOx emission limit and more severe test procedure compared to Euro IV and Euro V. This work proposed an approach to achieve model based closed loop control for SCR systems to meet the Euro VI NOx emission limits. A chemical kinetic model of the SCR catalyst was established and validated to estimate the ammonia storage in the SCR catalyst.
2017-10-08
Technical Paper
2017-01-2384
Ijhar H. Rusli, Svetlana Aleksandrova, Humberto Medina, Stephen F. Benjamin
Abstract In aftertreatment system design, flow uniformity is of paramount importance as it affects aftertreatment device conversion efficiency and durability. The major trend of downsizing engines using turbochargers means the effect of the turbine residual swirl on the flow needs to be considered. In this paper, this effect has been investigated experimentally and numerically. A swirling flow rig with a moving-block swirl generator was used to generate swirling flow in a sudden expansion diffuser with a wash-coated diesel oxidation catalyst (DOC) downstream. Hot-wire anemometry (HWA) was used to measure the axial and tangential velocities of the swirling flow upstream of the diffuser expansion and the axial velocity downstream the monolith. With no swirl, the flow in the catalyst monolith is highly non-uniform with maximum velocities near the diffuser axis. At high swirl levels, the flow is also highly nonuniform with the highest velocities near the diffuser wall.
2017-10-08
Journal Article
2017-01-2386
Naoki Ohya, Kohei Hiyama, Kotaro Tanaka, Mitsuru Konno, Atsuko Tomita, Takeshi Miki, Yutaka Tai
Abstract Diesel engines have better fuel economy over comparable gasoline engines and are useful for the reduction of CO2 emissions. However, to meet stringent emission standards, the technology for reducing NOx and particulate matter (PM) in diesel engine exhaust needs to be improved. A conventional selective catalytic reduction (SCR) system consists of a diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and urea-SCR catalyst. Recently, more stringent regulations have led to the development of SCR systems with a larger volume and increased the cost of such systems. In order to solve these problems, an SCR catalyst-coated DPF (SCR/DPF) is proposed. An SCR/DPF system has lower volume and cost compared to the conventional SCR system. The SCR/DPF catalyst has two functions: combustion of PM and reduction of NOx emissions.
2017-10-08
Technical Paper
2017-01-2388
Ahmad Khalfan, Gordon Andrews, Hu Li
Abstract The emissions from vehicles in real world driving are of current concern, as they are often higher than on legislated test cycles and this may explain why air quality in cities has not improved in proportion to the reduction in automotive emissions. This has led to the Real Driving Emissions (RDE) legislation in Europe. RDE involves journeys of about 90km with roughly equal proportion of urban, rural and motorway driving. However, air quality exceedances occur in cities with urban congested traffic driving as the main source of the emissions that deteriorate the air quality. Thus, the emissions measured on RDE journeys may not be relevant to air quality in cities. A Temet FTIR and Horiba exhaust flow measurement system was used for the mass emissions measurements in a Euro 4 SI vehicle. A 5km urban journey on a very congested road was undertaken 29 times at various times so that different traffic congestion was encountered.
2017-10-08
Technical Paper
2017-01-2391
Daisy Thomas, Hu Li, Xin Wang, Bin Song, Yunshan Ge, Wenlin Yu, Karl Ropkins
Abstract The drive characteristics and gaseous emissions of legislated Real Driving Emissions (RDE) test data from 8 different spark ignition vehicles were compared to data from corresponding Worldwide harmonized Light vehicles Test Cycle (WLTC) tests. The effect of the official RDE exclusion of cold start and idling on the RDE test, and the effect of the use of the moving averaging window (MAW) analysis technique, were simultaneously investigated. Specific attention was paid to differences in drive characteristics of the three different driving modes and the effect this had on the distance-based CO2, CO and NOx emission factors for each. The average velocity of the RDE tests was marginally greater than the WLTC tests, while the average acceleration was smaller. The CO2 emission appeared on average 4% lower under the RDE tests compared to the WLTC tests, while the CO was 60% lower.
2017-10-08
Technical Paper
2017-01-2394
Ning Xu, Di-ming Lou, Ji-yao Liu, Piqiang Tan, Zhiyuan Hu
Abstract The range-extended electric transit bus (REEbus) equipped with the auxiliary power unit (APU) using high efficient diesel engine as power source can reduce the cost of power battery and is an ideal transitional powertrain architecture to the pure electric drive. Based on chassis tests of a 12m long REEbus, fuel consumption and emission characteristics during Charge-Sustaining (CS) stage effected by temperature of the REEbus are researched. The APU of REEbus starts to work around just one point with best efficiency and lower emission when the state of charge (SOC) is too low and stop when the SOC is high, which aims to lower fuel consumption. As a result, even during CS stage, the fuel consumption of REEbus is only 22.84 L/100km. Also almost all emissions decrease dramatically and the NOx emission is only 0.68g/km, but the ultrafine-particle number increases owing to better combustion.
2017-10-08
Technical Paper
2017-01-2390
Hongxue Zhao, Daliang Jing, Yinhui Wang, Shi-jin Shuai, Changle PANG
Abstract In this paper, the impacts of Aromatic and Olefin on the formation of poly-aromatic hydrocarbons (PAHs) in the gasoline direct injection (GDI) engine were experimentally and numerically investigated. The objective of this study is to describe the formation process of the soot precursors including one ring to four ring aromatics (A1-A4). In order to better understand the effects of the fuel properties on the formations of PAHs. Three types of fuels, namely base gasoline, gasoline with higher aromatics content, and gasoline with higher olefin content were experimentally studied. At the same time, these aspects were also numerically investigated in the CHEMKIN code by using premixed laminar flame model and surrogated fuels. The results show that higher aromatics content in gasoline will lead to much higher PAHs formation. Similar trend was also found in the gasoline with higher olefin content.
2017-10-08
Technical Paper
2017-01-2393
E. Robert Fanick, Svitlana Kroll
Abstract Semi-volatile organic compounds (SVOC) are a group of compounds in engine exhaust that either form during combustion or are part of the fuel and lubricating oil. Since these compounds occur at very low concentrations in diesel engine exhaust, the methods for sampling, handling, and analyzing these compounds are critical to obtaining good results. An improved dilute exhaust sampling method was used for sampling and analyzing SVOC in engine exhaust, and this method was performed during transient engine operation. A total of 22 different SVOC were measured using a 2012 medium-duty diesel engine. This engine was equipped with a stock diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), and a selective catalytic reduction (SCR) catalyst in series. Exhaust concentrations for SVOC were compared both with and without exhaust aftertreatment. Concentrations for the engine-out SVOC were significantly higher than with the aftertreatment present.
2017-10-08
Technical Paper
2017-01-2398
Bei Liu, Xiaobei Cheng, Jialu Liu, Han Pu, Li Yi
Abstract Partially-premixed low-temperature combustion avoids the soot and NOx generation area on the Ф-T diagram to reduce both engine NOx and soot emissions. Compared with the HCCI combustion mode, partially-premixed combustion (PPC) has better combustion controllability. The purpose of controlling the combustion phase can be achieved by adjusting injection timing and strategy. Based on a 4 cylinder turbocharged diesel engine, this paper aims at investigating the influence of injection strategy to the engine combustion and emission formation under the condition of single injection and split injection PPC strategy respectively, in which the primary purpose focus on the emission characteristics of particles. Results show that the early-injection PPC formed by single injection can reduce the quantity, quality and geometric mean diameter (GMD) of particles obviously.
2017-10-08
Technical Paper
2017-01-2404
Douglas Ball, David Lewis, David Moser, Sanket Nipunage
Abstract Federal Test Procedure (FTP) emissions were measured on a 2009 4 cylinder 2.4L Malibu PZEV vehicle with 10 and 30ppm sulfur fuel while varying the PGM (Platinum Group Metals) of the close-coupled and underfloor converters. Base CARB PH-III certification fuel was used. Three consecutive FTPs were used to measure the impact of fuel sulfur and catalyst PGM loading combinations. In general, reducing fuel sulfur and increasing catalyst PGM loadings, decrease FTP emissions. Increasing Pd concentrations can mitigate the impact of higher fuel sulfur concentrations. The results also suggest that a 50% reduction in PGM can be achieved with a reduction in fuel sulfur from 30 to 10 ppm. On average, NMHC, CO and NOx emissions were reduced by 12, 49 and 64%, respectively with the 10 ppm sulfur fuel. In addition, HC and NOx vehicle emission variability were reduced by 74 and 57% with the 10 ppm sulfur fuel.
2017-10-08
Technical Paper
2017-01-2402
Yoshinori Otsuki, Shigemi Tochino, Kenji Kondo, Kazuhiko Haruta
Abstract Fine particle emissions from engine exhaust have attracted attention because of concern of their higher deposition fraction in alveoli. Since it was observed that sizes of solid particles in exhaust of conventional internal combustion engine technologies are mainly distributed above 30 nm and the mainly irreproducible sensitivity to volatile particles can be reduced, the current solid particle number (PN) measurement methodology was targeted to PN emissions particles larger than 23 nm. The necessity of the measurement of particles smaller than 23 nm is now under discussion. It is also surmised that there is difference between emissions under regulatory defined test cycles and real driving conditions. Currently, implementation of further real driving emission regulations utilizing portable emissions measurement systems (PEMS) is in place for the EU and being actively discussed in other regions.
2017-10-08
Technical Paper
2017-01-2363
Murugesa Pandian M, Anand Krishnasamy
Abstract Advanced low temperature combustion (LTC) modes are most promising to reduce green house gas emissions owing to fuel economy benefits apart from simultaneously reducing oxides of nitrogen (NOx) and particulate matter (PM) emissions from diesel engines. Various LTC strategies have been proposed so far and each of these LTC strategies have their own advantages and limitations interms of precise ignition control, achievable load range and higher unburned emissions. In the present work, a small single cylinder diesel engine is initially operated under conventional combustion mode at rated speed, varying load conditions to establish the base line reference data. Then, the engine is modified to operate under different LTC strategies including Homogenous Charge Compression Ignition (HCCI), Premixed Charge Compression Ignition (PCCI) and Reactivity Controlled Compression Ignition (RCCI).
2017-10-08
Technical Paper
2017-01-2365
Murugesa Pandian M, Anand Krishnasamy
Abstract Reactivity controlled compression ignition (RCCI) is one of the most promising low temperature combustion (LTC) strategies to achieve higher thermal efficiencies along with ultra low oxides of nitrogen (NOx) and particulate matter emissions. Small single cylinder diesel engines of air-cooled type are finding increasing applications in the agriculture pump-set and small utility power generation owing to their lower cost and fuel economy advantages. In the present work, a small single cylinder diesel engine is initially operated under conventional combustion mode at rated speed, varying load conditions to establish the base line reference data. Then, the engine is modified to operate under RCCI combustion mode with a newly designed cylinder head to accommodate a high pressure, fully flexible electronically controlled direct diesel fuel injection system, a low pressure gasoline port fuel injection system and an intake air pre heater.
2017-10-08
Technical Paper
2017-01-2364
Jiaqiang Li, Yunshan Ge, Chao He, Jianwei Tan, Zihang Peng, Zidi Li, Wei Chen, Shijie Wang
Abstract Urea SCR technology is the most promising technique to reduce NOx emissions from heavy duty diesel engines. 32.5wt% aqueous urea solution is widely used as ammonia storage species for the urea SCR process. The thermolysis and hydrolysis of urea produces reducing agent ammonia and reduces NOx emissions to nitrogen and water. However, the application of urea SCR technology has many challenges at low temperature conditions, such as deposits formation in the exhaust pipe, lack deNOx performance at low temperature and freezing below -12°C. For preventing deposits formation, aqueous urea solution is hardly injected into exhaust gas stream at temperature below 200°C. The aqueous urea solution used as reducing agent precursor is the main obstacle for achieving high deNOx performances at low temperature conditions. This paper presents a solid SCR technology for control NOx emissions from heavy duty diesel engines.
2017-10-08
Technical Paper
2017-01-2367
Ganesan Mahadevan, Sendilvelan Subramanian
Abstract Control of harmful emissions during cold start of the engine has become a challenging task over the years due to the ever increasing stringent emission norms. Positioning the catalytic converter closer to the exhaust manifold is an efficient way of achieving rapid light-off temperature. On the other hand, the resulting higher thermal loading under high-load engine operation may substantially cause thermal degradation and accelerate catalyst ageing. The objective of the present work is to reduce the light-off time of the catalyst and at the same time reduce the thermal degradation and ageing of the catalyst to the minimum possible extent by adopting an approach with Dynamic Catalytic Converter System (DCCS). The emission tests were conducted at the cold start of a 4 cylinder spark ignition engine with DCCS at different positions of the catalyst at no load conditions.
2017-10-08
Technical Paper
2017-01-2366
Wenzheng Xia, Yi Zheng, Xiaokun He, Dongxia Yang, Huifang Shao, Joesph Remias, Joseph Roos, Yinhui Wang
Abstract Because of the increased use of gasoline direct engine (GDI) in the automobile industry, there is a significant need to control particulates from GDI engines based on emission regulations. One potential technical approach is the utilization of a gasoline particulate filter (GPF). The successful adoption of this emission control technology needs to take many aspects into consideration and requires a system approach for optimization. This study conducted research to investigate the impact of vehicle driving cycles, fuel properties and catalyst coating on the performance of GPF. It was found that driving cycle has significant impact on particulate emission. Fuel quality still plays a role in particulate emissions, and can affect the GPF performance. Catalyzed GPF is preferred for soot regeneration, especially for the case that the vehicle operation is dominated by congested city driving condition, i.e. low operating temperatures.
2017-10-08
Technical Paper
2017-01-2368
Wenji Song, Weiyong Tang, Bob Chen
Abstract The 4JB1 diesel engine originated from Isuzu has large share in the China light duty truck market. However, the tightened NOx emission target enforced by NS-V legislation compared with NS-IV regulatory standard is very challenging for this engine platform which originally adopted the DOC+POC catalyst layout. Furthermore, combustion characterization of this type engine leads to high soluble organic fraction (SOF) content in engine out particulates, which requires the catalysts in the exhaust after-treatment system (ATS) to deliver high SOF conversion efficiency in order to meet the regulation limit for particulate matters (PM). In this paper, an innovative exhaust catalyst layout with DOC+V-SCR is introduced. The front DOC is specially formulated with optimized PGM (Platinum Group Metal) loading which ensures effective SOF oxidation while keeping sulfuric acid and sulfate generation minimal.
Viewing 31 to 60 of 22030