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Viewing 61 to 90 of 22754
2015-04-14
Journal Article
2015-01-0810
Hao-ye Liu, Zhi Wang, Jian-Xin Wang
Abstract Wide Distillation Fuel (WDF) refers to the fuels with a distillation range from Initial Boiling Point (IBP) of gasoline to Final Boiling Point (FBP) of diesel. Polyoxymethylene Dimethyl Ethers (PODEn) have high oxygen content and cetane number, are promising green additive to diesel fuel. In this paper, WDF was prepared by blending diesel and gasoline at ratio of 1:1, by volume; the mass distribution of oligomers in the PODE3-4 product was 88.9% of PODE3 and 8.46% of PODE4. Diesel fuel (Diesel), WDF (G50D50) and WDF (80%)-PODE3-4 (20%) (G40D40P20) were tested in a light-duty single-cylinder diesel engine, combustion characteristic, fuel consumption and exhaust emissions were measured. The results showed that: at idling condition, G40D40P20 has better combustion stability, higher heat release rate, higher thermal efficiency compared with G50D50.
2015-04-14
Technical Paper
2015-01-0800
Yann Gallo, Johan Simonsson, Ted Lind, Per-Erik Bengtsson, Henrik Bladh, Oivind Andersson
Abstract Two competing in-cylinder processes, soot formation and soot oxidation, govern soot emissions from diesel engines. Previous studies have shown a lack of correlation between the soot formation rate and soot emissions. The current experiment focuses on the correlation between soot oxidation rates and soot emissions. Laser extinction is measured using a red (690nm) laser beam, which is sent vertically through the cylinder. This wavelength is long enough to minimize absorption interference from poly-aromatic hydrocarbons, while still in the visible regime. It is modulated at 72 kHz in order to produce 10 pulses per crank angle degree at an engine speed of 1200 rpm. The intake oxygen concentration is varied between 9% and 21%. The time resolved extinction measurements are used to estimate soot oxidation rates during expansion.
2015-04-14
Journal Article
2015-01-0255
Claudia Meis, Stefan Mueller, Stephan Rohr, Matthias Kerler, Markus Lienkamp
Abstract Battery aging in electric and hybrid vehicles is a major issue, and one which has to be taken into consideration during all stages of the vehicle lifecycle. It depends on many factors, such as the cell chemistry, the cell design and stress factors as well as the current rate, ΔDOD and temperature. The stress factors have been identified as being crucial due to their influence on two important battery parameters: capacity and inner resistance. Battery aging models are essential to describing the interacting influences that stress factors have on battery parameters. They provide insights about battery aging without the need for extensive measurements. Various battery aging models with widely varying capabilities are described in the literature. The aim of this paper is to provide a decision guide for utilizing the most appropriate aging model for the major stages of the vehicle lifecycle: vehicle development, operation (onboard and offboard) and post-operation.
2015-04-14
Technical Paper
2015-01-0343
Carlo N. Grimaldi, Claudio Poggiani, Alessandro Cimarello, Matteo De Cesare, Giovanni Osbat
Abstract The emissions limits of CO2 for vehicles are becoming more stringent with the aim of reducing greenhouse gas emissions and improve fuel economy. The New European Driving Cycle (NEDC) is adopted to measure emissions for all new internal combustion engines in the European Union, and it is performed on cold vehicle, starting at a temperature of 22°C ± 2°C. Consequently, the cold-start efficiency of internal combustion engine is becoming of predominant interest. Since at cold start the lubricant oil viscosity is higher than at the target operating temperature, the consequently higher energy losses due to increased frictions can substantially affect the emission cycle results in terms of fuel consumption and CO2 emissions. A suitable thermal management system, such as an exhaust-to-oil heat exchanger, could help to raise the oil temperature more quickly.
2015-04-14
Technical Paper
2015-01-0389
Zhichao Zhao, Zhengxin Xu, Jingping Liu, Mianzhi Wang, Chia-Fon Lee, Wayne Chang, Jie Hou
Abstract A multi-step acetone-butanol-ethanol (ABE) phenomenological soot model was proposed and implemented into KIVA-3V Release 2 code. Experiments were conducted in an optical constant volume combustion chamber to investigate the combustion and soot emission characteristics under the conditions of 1000 K initial temperature with various oxygen concentrations (21%, 16%, 11%). Multi-dimensional computational fluid dynamics (CFD) simulations were conducted in conjunction under the same operation conditions. The predicted soot mass traces showed good agreement with experimental data. As ambient oxygen decreased from 21% to 11%, ignition delay retarded and the distribution of temperature became more homogenous. Compared to 21% ambient oxygen, the peak value of total soot mass at 16% oxygen concentration was higher due to the suppressed soot oxidation mechanism.
2015-04-14
Technical Paper
2015-01-0394
Nicola Giovannoni, Alessandro d'Adamo, Giuseppe Cicalese, Giuseppe Cantore
Abstract Fuel deposits in DISI engines promote unburnt hydrocarbon and soot formation: due to the increasingly stringent emission regulations (EU6 and forthcoming), it is necessary to deeply analyze and well-understand the complex physical mechanisms promoting fuel deposit formation. The task is not trivial, due to the coexistence of mutually interacting factors, such as complex moving geometries, influencing both impact angle and velocity, and time-dependent wall temperatures. The experimental characterization of actual engine conditions on transparent combustion chambers is limited to highly specialized research laboratories; therefore, 3D-CFD simulations can be a fundamental tool to investigate and understand the complex interplay of all the mentioned factors. The aim is pursued in this study by means of full-cycle simulations accounting for instantaneous fuel/piston thermal interaction and actual fuel characteristics.
2015-04-14
Journal Article
2015-01-0440
Julio Carrera, Alfredo Navarro, Concepcion Paz, Alvaro Sanchez, Jacobo Porteiro
Recent emissions standards have become more restrictive in terms of CO2 and NOx reduction. This has been translated into higher EGR rates at higher exhaust gas temperatures with lower coolant flow rates for much longer lifetimes. In consequence, thermal load for EGR components, specially EGR coolers, has been increased and thermal fatigue durability is now a critical issue during the development. Consequently a new Thermo-Mechanical Analysis (TMA) procedure has been developed in order to calculate durability. The TMA calculation is based on a Computational Fluid Dynamics simulation (CFD) in which a boiling model is implemented for obtaining realistic temperature predictions of the metal parts exposed to possible local boiling. The FEM model has also been adjusted to capture the correct stress values by submodeling the critical areas. Life calculation is based on a Multiaxial Fatigue Model that has also been implemented in FEM software for node by node life calculation.
2015-04-14
Technical Paper
2015-01-0264
Jeya Padmanaban
Abstract This study examined the Consumer Product Safety Commission (CPSC) Death Certificate file to identify frequency and rate of accidental CO poisoning deaths associated with exhaust gases of stationary vehicles in enclosed areas. A comprehensive search was then made to determine whether or not there was an increase in such deaths with the introduction of “smart keys” (available as standard equipment beginning in 2004). For 2000-2011 CY, the CPSC file contained 4,760 death certificate records for ICD-10 code X47 (accidental poisoning by exposure to other gases and vapors). The manual review of narratives for these records covered 2004-2011 and found 1,553 CO poisoning deaths associated with vehicle exhaust, including 748 for enclosed areas. For these 748 incidents, information on victim and location was then identified, and an exhaustive effort was undertaken to determine whether the vehicles involved were equipped with rotary or smart keys.
2015-04-14
Technical Paper
2015-01-1740
Kelsie S. Richmond, Stephen Henry, Russell Richmond, David Belton
Gasket materials are utilized for various different types of high temperature testing to prevent leaking at bolted joints. In particular, the automotive test services field uses flanged-gasket bolted exhaust joints to provide a convenient method for installation & removal of exhaust components like catalytic converters for aging, performance testing, etc. Recent improvements in the catalyst aging methods require flanged-gasket joints that can withstand exhaust temperatures as high as 1200°C. Gasket materials previously used in these applications like the graphite based gasket materials have exhibited physical breakdowns, severe leakage, and general thermal failures under these extreme temperatures. In order to prevent these leaks, metal-reinforced gasket materials in a number of configurations were introduced to these extreme temperature environments to evaluate their robustness to these temperatures.
2015-04-14
Journal Article
2015-01-1746
Hassan Karaky, Gilles Mauviot, Xavier Tauzia, Alain Maiboom
Abstract Reducing NOx tailpipe emissions is one of the major challenges when developing automotive Diesel engines which must simultaneously face stricter emission norms and reduce their fuel consumption/CO2 emission. In fact, the engine control system has to manage at the same time the multiple advanced combustion technologies such as high EGR rates, new injection strategies, complex after-treatment devices and sophisticated turbocharging systems implemented in recent diesel engines. In order to limit both the cost and duration of engine control system development, a virtual engine simulator has been developed in the last few years. The platform of this simulator is based on a 0D/1D approach, chosen for its low computational time. The existing simulation tools lead to satisfactory results concerning the combustion phase as well as the air supply system. In this context, the current paper describes the development of a new NOx emission model which is coupled with the combustion model.
2015-04-14
Technical Paper
2015-01-0379
Yongli Qi, Xinyu Ge, Lichun Dong
The hybrid vehicle engines modified for high exhaust gas recirculation (EGR) is a good choice for high efficiency and low NOx emissions. However, high EGR will dilute the engine charge and may cause serious performance problems, such as incomplete combustion, torque fluctuation, and engine misfire. An efficient way to overcome these drawbacks is to intensify tumble leading to increased turbulent intensity at the time of ignition. The enhancement of turbulent intensity will increase flame velocity and improve combustion quality, therefore increasing engine tolerance to higher EGR. To achieve the goal of increasing tolerance to EGR, this work reports a CFD investigation of high tumble intake port design using STAR-CD. The validations had been performed through the comparison with PIV experimental tests.
2015-04-14
Journal Article
2015-01-0730
Tsutomu Miyadera
Abstract A pre-treatment technique for improving coating adhesion on stainless steel has been developed. This method dramatically enhances the adhesion between the stainless steel and the coating by pre-treating the stainless steel with a known nickel strike plating for a short period of time. Furthermore, when this process was applied to stainless fuel filler pipes to improve corrosion resistance, layout restrictions and chipping covers became unnecessary, costs were reduced, and vehicle weight was lowered.
2015-04-14
Journal Article
2015-01-1017
Yuki Jin, Narimasa Shinoda, Yosuke Uesaka, Tatsuyuki Kuki, Masataka Yamashita, Hirofumi Sakamoto, Tasuku Matsumoto, Philipp Kattouah, Claus Dieter Vogt
Abstract Since the implementation of Euro 6 in September 2014, diesel engines are facing another drastic reduction of NOx emission limits from 180 to only 80 mg/km during NEDC and real driving emissions (RDE) are going to be monitored until limit values are enforced from September 2017. Considering also long term CO2 targets of 95 g/km beyond 2020, diesel engines must become cleaner and more efficient. However, there is a tradeoff between NOx and CO2 and, naturally, engine developers choose lower CO2 because NOx can be reduced by additional devices such as EGR or a catalytic converter. Lower CO2 engine calibration, unfortunately, leads to lower exhaust gas temperatures, which delays the activation of the catalytic converter. In order to overcome both problems, higher NOx engine out emission and lower exhaust gas temperatures, new aftertreatment systems will incorporate close-coupled DeNOx systems.
2015-04-14
Journal Article
2015-01-1027
David Culbertson, Magdi Khair, Sanhong Zhang, Julian Tan, Jacob Spooler
Abstract SCR cold-start effects are increasingly important for meeting today's emission requirements [1]. A significant challenge toward quickly achieving NOx abatement is the presence of moisture in the catalyst at lower temperatures [1]. This paper describes the ability of an electric heater to effectively raise the temperature of the exhaust and overcome the effect of moisture and low exhaust temperature, allowing NOx conversion to begin sooner. A model of the moisture storage and removal is presented, along with results from engine tests. Results show that it is possible to achieve high NOx conversion temperatures quickly with robust heater technology that is suited for diesel applications.
2015-04-14
Technical Paper
2015-01-1067
Kenneth S. Price, Lin Wang, Thomas Pauly
Abstract Investigations of on-road emissions performance of vehicles have been made using various methods and instrumentation, some of which are very complex and costly. For the particular case of NOx emissions on Diesel road vehicles equipped with SCR catalysts (Selective Catalytic Reduction), many of these vehicles are equipped with NOx sensor(s) for the purpose of OBD (On-Board Diagnostics), and the ECU (Engine Control Unit) makes this data available via the diagnostic connector under the SAEJ1979 protocol for light duty vehicles. Data for mass air flow and fuel flow are also available per J1979, so the ongoing NOx mass flow can be estimated when the NOx sensors are active with no additional instrumentation. Heavy duty pickup trucks with SCR systems from 3 major US manufacturers, each certified to the optional chassis certification of 0.2 g/mi NOx on the FTP75, were obtained to be evaluated for SCR system behavior under normal driving conditions.
2015-04-14
Technical Paper
2015-01-0898
Leonardo Pellegrini, Carlo Beatrice, Gabriele Di Blasio
Abstract Hydrotreated vegetable oil (HVO) is a renewable high quality paraffinic diesel that can be obtained by the hydrotreating of a wide range of biomass feedstocks, including vegetable oils, animal fats, waste oils, greases and algal oils. HVO can be used as a drop-in fuel with beneficial effects for the engine and the environment. The main objective of this study was to explore the potential of HVO as a candidate bio blendstock for new experimental formulations of diesel fuel to be used in advanced combustion systems at different compression ratios and at high EGR rates in order to conform to the Euro 6 NOx emission standard. The experiments were carried out in a single-cylinder research engine at three steady-state operating conditions and at three compression ratios (CR) by changing the piston.
2015-04-14
Technical Paper
2015-01-0895
Senthilkumar Masimalai, Venkatesan Kuppusamy, Jaikumar Mayakrishnan
Abstract This paper aims at studying the effect of oxygen enriched combustion on performance, emission and combustion characteristics of a diesel engine using waste cooking oil (WCO) derived from palm oil as fuel. A single cylinder water-cooled, direct injection diesel engine was used. The intake system of the engine was modified to accommodate excess oxygen in the incoming air. Base data was generated using diesel as fuel. Subsequently experiments were repeated with WCO for different oxygen concentrations such as 21% (WCO+21%O2), 23% (WCO+23%O2), 24% (WCO+24%O2) and 25% (WCO+25%O2) by volume. Engine performance, emission and combustion parameters were obtained at different power outputs and analyzed. Results showed reduced brake thermal efficiency, higher smoke, hydrocarbon and carbon monoxide emissions with WCO+21%O2 as compared to diesel at all power outputs.
2015-04-14
Journal Article
2015-01-0902
Koichi Ashida, Hirofumi Maeda, Takashi Araki, Maki Hoshino, Koji Hiraya, Takao Izumi, Masayuki Yasuoka
Abstract To improve the fuel economy via high EGR, combustion stability is enhanced through the addition of hydrogen, with its high flame-speed in air-fuel mixture. So, in order to realize on-board hydrogen production we developed a fuel reformer which produces hydrogen rich gas. One of the main issues of the reformer engine is the effects of reformate gas components on combustion performance. To clarify the effect of reformate gas contents on combustion stability, chemical kinetic simulations and single-cylinder engine test, in which hydrogen, CO, methane and simulated gas were added to intake air, were executed. And it is confirmed that hydrogen additive rate is dominant on high EGR combustion. The other issue to realize the fuel reformer was the catalyst deterioration. Catalyst reforming and exposure test were carried out to understand the influence of actual exhaust gas on the catalyst performance.
2015-04-14
Technical Paper
2015-01-0903
Neeraj Mittal, Pradeep Patanwal, M Sithananthan, M Subramanian, Ajay Kumar Sehgal, R Suresh, B P Das
Abstract N-butanol is a promising alternative fuel which needs no engine modification when used as a blend with diesel. The miscibility of n-butanol with diesel is excellent in a wide range of blending ratios. N-butanol has high oxygen content and a comparable energy content, specific gravity and viscosity to that of diesel, which makes it attractive for diesel engines as an alternative fuel. An experimental investigation was conducted to assess the performance of a new generation passenger car with respect to power, fuel economy (FE) and mass emission using 5, 10 and 20 percent (by vol.) n-butanol blends with diesel (NB). Computer controlled DC motor driven chassis dynamometer, AVL AMA I60 mass emission measuring system and AVL FSN smoke meter were used for measuring wide open throttle (WOT) power, road load simulation (RLS) fuel economy, mass emissions and smoke in WOT and steady speed driving conditions.
2015-04-14
Technical Paper
2015-01-0889
Jai Gopal Gupta, Avinash Kumar Agarwal
Abstract Use of biodiesel from non-edible vegetable oil as an alternative fuel to mineral diesel is attractive economically and environmentally. Diesel engines emit several harmful gaseous emissions and some of them are regulated worldwide, while countless others are not regulated. These unregulated species are associated with severe health hazards. Karanja biodiesel is a popular alternate fuel in South Asia and various governments are considering its large-scale implementation. Therefore it is important to study the possible adverse impact of this new alternate fuel. In this study, unregulated and regulated emissions were measured at varying engine speeds (1500, 2500 and 3500 rpm) for various engine loads (0%, 20%, 40%, 60%, 80% and 100% rated load) using 20% Karanja biodiesel blend (KB20) and diesel in a 4-cylinder 2.2L common rail direct injection (CRDI) sports utility vehicle (SUV) engine.
2015-04-14
Technical Paper
2015-01-0914
Ehsan Tootoonchi, Gerald Micklow
Abstract Understanding the physics and chemistry involved in diesel combustion, with its transient effects and the inhomogeneity of spray combustion is quite challenging. Great insight into the physics of the problem can be obtained when an in-cylinder computational analysis is used in conjunction with either an experimental program or through published experimental data. The main area to be investigated to obtain good combustion begins with the fuel injection process and the mean diameter of the fuel particle, injection pressure, drag coefficient, rate shaping etc. must be defined correctly. The increased NOx production and reduced power output found in engines running biodiesel in comparison to petrodiesel is believed to be related to the different fuel characteristics in comparison to petroleum based diesel. The fuel spray for biodiesel penetrates farther into the cylinder with a smaller cone angle. Also the fuel properties between biodiesel and petrodiesel are markedly different.
2015-04-14
Technical Paper
2015-01-0905
Seyed Hadavi, Buland Dizayi, Hu Li, Alison Tomlin
Abstract To maximize CO2 reduction, refined straight used cooking oils were used as a fuel in Heavy Goods Vehicles (HGVs) in this research. The fuel is called C2G Ultra Biofuel (C2G: Convert to Green Ltd) and is a fully renewable fuel made as a diesel replacement from processed used cooking oil, used directly in diesel engines specifically modified for this purpose. This is part of a large demonstration project involving ten 44-tonne trucks using C2G Ultra Biofuel as a fuel to partially replace standard diesel fuels. A dual fuel tank containing both diesel and C2G Ultra Biofuel and an on-board fuel blending system-Bioltec system was installed on each vehicle, which is able to heat the C2G Ultra Biofuel and automatically determine the required blending ratio of diesel and C2G Ultra Biofuel according to fuel temperature and engine load. The engine was started with diesel and then switched to C2G Ultra Biofuel under appropriate conditions.
2015-04-14
Technical Paper
2015-01-0910
Lei Zhou, Benedikt Heuser, Michael Boot, Florian Kremer, Stefan Pischinger
Abstract Lignocellulosic biomass consists of (hemi-) cellulose and lignin. Accordingly, an integrated biorefinery will seek to valorize both streams into higher value fuels and chemicals. To this end, this study evaluated the overall combustion performance of both cellulose- and lignin derivatives, namely the high cetane number (CN) di-n-butyl ether (DnBE) and low CN anisole, respectively. Said compounds were blended both separately and together with EN590 diesel. Experiments were conducted in a single cylinder compression ignition engine, which has been optimized for improved combustion characteristics with respect to low emission levels and at the same time high fuel efficiency. The selected operating conditions have been adopted from previous “Tailor-Made Fuels from Biomass (TMFB)” work.
2015-04-14
Technical Paper
2015-01-0908
Yuqiang Li, Karthik Nithyanandan, Jiaxiang Zhang, Chia-Fon Lee, Shengming Liao
Abstract Butanol has proved to be a very promising alternative fuel in recent years. The production of bio-butanol, typically done using the acetone-butanol-ethanol (ABE) fermentation process is expensive and consumes a lot of energy. Hence it is of interest to study the intermediate fermentation product, i.e. water-containing ABE as a potential fuel. The combustion and emissions performance of ABE29.5W0.5 (29.5 vol.% ABE, 0.5 vol.% water and gasoline blend), ABE30 (30 vol.% ABE and gasoline blend) and ABE0 (pure gasoline) were investigated in this study. The results showed that ABE29.5W0.5 enhanced engine torque by 9.6%-12.7% and brake thermal efficiency (BTE) by 5.2%-11.6% compared to pure gasoline, respectively. ABE29.5W0.5 also showed similar brake specific fuel consumption (BSFC) relative to pure gasoline.
2015-04-14
Technical Paper
2015-01-0909
Karthik Nithyanandan, Jiaxiang Zhang, Li Yuqiang, Han Wu, Chia-Fon Lee
Abstract Alcohols, especially n-butanol, have received a lot of attention as potential fuels and have shown to be a possible alternative to pure gasoline. The main issue preventing butanol's use in modern engines is its relatively high cost of production. ABE, the intermediate product in the ABE fermentation process for producing bio-butanol, is being studied as an alternative fuel because it not only preserves the advantages of oxygenated fuels, but also lowers the cost of fuel recovery for individual component during fermentation. With the development of advanced ABE fermentation technology, the volumetric percentage of acetone, butanol and ethanol in the bio-solvents can be precisely controlled. In this respect, it is desirable to estimate the performance of different ABE blends to determine the best blend and optimize the production process accordingly.
2015-04-14
Technical Paper
2015-01-0863
Hideyuki Ogawa, Peilong Zhao, Taiki Kato, Gen Shibata
Abstract Dual fuel combustion with premixed natural gas as the main fuel and diesel fuel as the ignition source was investigated in a 0.83 L, single cylinder, DI diesel engine. At low loads, increasing the equivalence ratio of natural gas to around 0.5 with intake throttling makes it possible to reduce the THC and CO emissions as well as to improve the thermal efficiency. At high loads, increasing the boost pressure moderates the combustion, but increases the THC and CO emissions, resulting in deterioration of the thermal efficiency. The EGR is essential to suppress the rapid combustion. As misfiring occurs with a compression ratio of 14.5 and there is excessively rapid combustion with 18.5 compression ratio, 16.5 is a suitable compression ratio.
2015-04-14
Technical Paper
2015-01-0854
Jeongwoo Lee, Sanghyun Chu, Jaehyuk Cha, Hoimyung Choi, Kyoungdoug Min
Abstract In this work, the operating strategy for diesel injection methods and a way to control the exhaust gas recirculation (EGR) rate under dual-fuel PCCI combustion with an appropriate ratio of low-reactivity fuel (propane) to achieve high combustion stability and low emissions is introduced. The standards of combustion stability were carbon monoxide (CO) emissions below 5,000 ppm and a CoV of the indicated mean effective pressure (IMEP) below 5 %. Additionally, the NOx emissions was controlled to not exceed 50 ppm, which is the standard of conventional diesel combustion, and PM emissions was kept below 0.2 FSN, which is a tenth of the conventional diesel value without a diesel particulate filter (DPF). The operating condition was a low speed and load condition (1,500 rpm/ near gIMEP of 0.55 MPa).
2015-04-14
Technical Paper
2015-01-0861
Matthew Younkins, Margaret S. Wooldridge, Brad A. Boyer
Abstract Hydrogen fueled internal combustion engines have potential for high thermal efficiencies; however, high efficiency conditions can produce high nitrogen oxide emissions (NOx) that are challenging to treat using conventional 3-way catalysts. This work presents the results of an experimental study to reduce NOx emissions while retaining high thermal efficiencies in a single-cylinder research engine fueled with hydrogen. Specifically, the effects on engine performance of the injection of water into the intake air charge were explored. The hydrogen fuel was injected into the cylinder directly. Several parameters were varied during the study, including the amount of water injected into the intake charge, the amount of fuel injected, the phasing of the fuel injection, the number of fuel injection events, and the ignition timing. The results were compared with expectations for a conventionally operated hydrogen engine where load was controlled through changes in equivalence ratio.
2015-04-14
Technical Paper
2015-01-0873
Bin Mao, Mingfa Yao, Zunqing Zheng, Yongzhi Li, Haifeng Liu, Bowen Yan
Abstract An experimental study is carried out to compare the effects of high-pressure-loop, low-pressure-loop and dual-loop exhaust gas recirculation systems (HPL-EGR, LPL-EGR and DL-EGR) on the combustion characteristics, thermal efficiency and emissions of a diesel engine. The tests are conducted on a six-cylinder turbocharged heavy-duty diesel engine under various operating conditions. The low-pressure-loop portion (LPL-Portion) of DL-EGR is swept from 0% to 100% at several constant EGR rates, and the DL-EGR is optimized based on fuel efficiency. The results show that the LPL-EGR can attain the highest gross indicated thermal efficiency (ITEg) in the three EGR systems under all the tested conditions. At a middle load of 0.95 BMEP, 1660 r/min, the pumping losses of LPL-EGR lead to the lowest BTE among the EGR systems. The HPL-EGR can achieve the best brake thermal efficiency (BTE) and emissions within the EGR rate of 22.5% mainly due to the reduced pumping losses.
2015-04-14
Technical Paper
2015-01-1001
Shinichiro Otsuka, Yukio Suehiro, Hiroshi Koyama, Yoshiaki Matsuzono, Cameron Tanner, David Bronfenbrenner, Tinghong Tao, Kenneth Twiggs
Abstract With the increasing number of automobiles, the worldwide problem of air pollution is becoming more serious. The necessity of reducing tail-pipe emissions is as high as ever, and in countries all over the world the regulations are becoming stricter. The emissions at times such as after engine cold start, when the three-way catalyst (TWC) has not warmed up, accounts for the majority of the emissions of these pollutants from vehicles. This is caused by the characteristic of the TWC that if a specific temperature is not exceeded, TWC cannot purify the emissions. In other words, if the catalyst could be warmed up at an early stage after engine start, this would provide a major contribution to reducing the emissions. Therefore, this research is focused on the substrate weight and investigated carrying out major weight reduction by making the porosity of the substrate larger than that of conventional products.
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