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2016-10-17
Technical Paper
2016-01-2165
Kazuya Miyashita, Takamichi Tsukamoto, Yusei Fukuda, Katsufumi Kondo, Tetsuya Aizawa
For better understanding of in-cylinder soot formation processes of Gasoline Direct Injection (GDI) engines, visualization via high-speed UV (266nm) and visible (445nm) laser shadowgraphy of piston surface fuel wetting, vaporization and soot formation processes of in-cylinder pool fire was attempted in a Rapid Compression and Expansion Machine (RCEM). A direct-injection, spark-ignition and single-shot combustion event was achieved in the RCEM operated with engine speed 600 rpm, compression ratio 9.0, equivalence ratio 0.9 and natural aspiration. The tested fuel was composed of 70% iso-octane and 30% toluene by volume and the UV absorption by toluene enabled visualization of the in-cylinder fuel distribution. Significant UV absorption was caused also by in-cylinder soot particles, which was reasonably distinguishable from the fuel by comparing the UV shadowgraphs with visible shadowgraphs and direct photographs of soot taken under identical conditions.
2016-10-17
Technical Paper
2016-01-2179
Marius Zubel, Om Parkash Bhardwaj, Benedikt Heuser, Bastian Holderbaum, Sebastian Doerr, Jukka Nuottimäki
The present work represents a continuation of the earlier results published by the authors on combustion and emission investigation of neat Hydrogenated Vegetable Oil (HVO) in a High Efficiency Diesel Combustion System (SAE Int. J. Fuels Lubr.: 2013-01-1677, 2014-01-2846). The results indicate a significant reduction in CO-, HC- and Noise emissions at constant NOx levels. With regards to soot emissions, at higher part loads the aromatic free, paraffinic composition of HVO shows a significant reduction than EN 590 petroleum Diesel but at lower loads the high cetane number leads to shorter ignition delays, and therefore, ignition under richer conditions caused slightly increased soot emissions. This drawback could be compensated with an optimized engine calibration but in this work, an advanced fuel formulation approach is investigated to further improve the emission behavior.
2016-10-17
Technical Paper
2016-01-2181
Yong Qian, Yahui Zhang, Liang Yu, Zhen Huang, Xing-cai Lu
In this paper, an experimental study based on a modified single cylinder diesel oil engine has been conducted to study the effects of diesel oil blending different iso-alkanes on the combustion and emissions. Iso-octane, iso-dodecane and 2,2,4,4,6,8,8-Heptamethylnonane (HMN) were chosen as iso-alkanes. During the experiment, the direct injection timing was kept at 7 oCA BTDC, and the injection pressure was maintained at 120MPa. The study found that after blending iso-alkanes, the changes of fuel physical properties have significant effects on the heat release phase under low load. However, the effects are weakened gradually with the improvement of loads. The peak value of heat release curves and the maximum pressure rising rate gradually increase with the improvement of loads after mixing with iso-alkanes.
2016-10-17
Technical Paper
2016-01-2180
Vedharaj Sivasankaralingam, Vallinayagam Raman, mohammed jaasim Mubarak ali, Adamu Alfazazi, Tianfeng Lu, Hong Im, S. Mani Sarathy, Robert dibble
The auto ignition behavior of diethyl ether (DEE) in ethanol was investigated in CI engine both numerically and experimentally. While DEE has a higher cetane number of 139, ethanol exhibits poor ignition characteristics with a cetane number of 8. Therefore, DEE was used as an ignition promoter for the operation of ethanol in CI engine. Mixtures of DEE and ethanol (DE) such as DE75 (75% DEE + 25% ethanol), DE50 (50% DEE + 50% ethanol) and DE25 (25% DEE + 75% ethanol) were tested in a CI engine. While DE75 and DE50 autoignited at an inlet air pressure of 1.5 bar, DE25 failed to autoignite even at boosted conditions up to 2 bar. The peak in-cylinder pressures for diesel and DE75 were comparable, while DE50 showed reduced peak in-cylinder pressure with delayed start of combustion (SOC). The combined effect of high reactivity of DEE and the autoignition suppression of ethanol were also numerically investigated.
2016-10-17
Technical Paper
2016-01-2184
Manuel A. Gonzalez D, Davide Di Nunno
Future more stringent requirements for emissions reductions and higher fuel economy require more efficient higher energy extraction in the cylinder, trending to lower exhaust gas temperatures, challenging the energy availability for after treatment components. Methods are required to increase the efficiency of the exhaust thermal management, and Internal Exhaust Gas Recirculation (I-EGR) can increase the exhaust temperature in favor of earlier after treatment activation or for maintaining sustained higher after treatment efficiencies. I-EGR capability has been studied in a Diesel engine through the secondary opening of exhaust valves for more efficient recirculation of exhaust gases from a previous engine cycle to the cylinder mass charge during the intake stroke. I-EGR alone could increase exhaust gas temperature up to a limit soot emissions.
2016-10-17
Technical Paper
2016-01-2186
Prakash Narayanan Arunachalam, Marcus Thern, Per Tunestal, Martin Tuner
Humid air motor (HAM) is an engine operated with humidified inlet charge. System simulations study on HAM showed the waste heat recovery potential over conventional system. To comprehend the potential benefits in real-time, an HAM setup was constructed. The HAM setup was built around a 13-litre six cylinder Volvo diesel engine. The HAM engine process is explained in detail in this paper. Emission analysis is also performed for all three modes of operation. The experiments were carried out at part load operating point of the engine to understand the effects of humidified charge on combustion, efficiency and emissions. Experiments were conducted without EGR, with EGR and with humidified inlet charge. These three modes of operation furnished the potential benefits of each system. Exhaust heat is used for partial humidification process. Results shows that HAM operation without compromising on efficiency reduces the NOx and soot significantly over the EGR operated engine.
2016-10-17
Technical Paper
2016-01-2187
Haifeng Liu, Huixiang Zhang, Hu Wang, Xian Zou
In order to meet the IMO Tier III nitrogen oxide (NOX) emission regulations and find a feasible solution, large two-stroke slow speed marine engine are studied. 1-D engine working cycle simulation and 3-D CFD simulation models were established and calibrated against the experiment data for 75% load operation at 112r/min. The models were conducted to predict the performance and emissions for the engine under different exhaust valve close timings, intake pressures and EGR rates. The simulated results indicate that the variation of Miller timings can effectively decrease the region of high temperature and improve the levels and trade-off relationship of NOX and soot. However, the negative effect of Miller cycle brings the deficiency of fresh charge .It is essential to combine the Miller cycle with two-stage turbo charging .It is found that high boost pressure with EGR could further decrease the amount of NOX .In addition ,both NOX and soot can decrease when fuel-air ratio is constant.
2016-10-17
Technical Paper
2016-01-2195
Sebastian Bornschlegel, Chris Conrad, Michael Wensing, Tobias Knorsch, Philipp Rogler, Wolfram Wiese
Tip sooting is a mechanism of soot generation in direct injecting spark ignition (DISI) engines. It occurs during and after the combustion near the injector nozzle tip and is caused by degassing and evaporation of fuel wall films on the injector tip as well as by residual fuel in the dead volume after the end of injection. With the strict regulations of particulate engine emissions, these effects have to be controlled by injector manufacturers in order to meet future emission legislatives. In this paper a highspeed Schlieren measurement technique is presented in detail, which provides a robust possibility for time and space resolved visualization of evaporation processes by using a modern spray chamber. The chamber flushing is optimized in order to minimize perturbation of the degassing phenomena. Due to high sensitivity towards gradients in the refractive index, even small amounts of fuel-vapor can be detected.
2016-10-17
Technical Paper
2016-01-2283
Stephane Zinola, Stephane Raux, Mickael Leblanc lng
The more and more stringent regulations on particle emissions at the vehicle tailpipe have led the car manufacturers to adopt suitable emissions control systems, like particulate filters with average filtration efficiency that can exceed 99%, including particulate mass (PM) and number (PN). However, there are still some specific operating conditions that could exhibit noticeable particle number emissions. This paper aims to identify and characterize these persistent sources of PN emissions. Firstly, focus was given to Diesel engines, for which the Diesel Particulate Filter (DPF) is now very widespread. Tests, carried out both on the engine test bench and on the chassis dynamometer, have shown the presence of particles downstream of the DPF during some operation conditions like engine warm up or filter regeneration phases. PN could be 7 times higher during the warm up phase and can reach as much as 500 to 2000 times more during the regeneration phase compared to normal operation.
2016-10-17
Technical Paper
2016-01-2284
Yuan Wen, Yinhui Wang, Yinhui Wang, Haichun ding, Shi-Jin Shuai
Direct Injection Gasoline (DIG) engine developed rapidly in recent years driven by the requirements of higher fuel efficiency and lower fuel consumption, but faces the challenges of injector deposit and emissions especially particulate emission compared to Port Fuel Injection (PFI) engine. However it has not been revealed through system approach that the qualitative and quantitative impact of injector deposit formation on particulate emission of DIG vehicle through vehicle emission testing and injector spray analysis. In this paper, an experimental study was conducted on a DIG vehicle produced by a Chinese Original Equipment Manufacturer (OEM) to investigate the impact of injector deposit on spray and particulate emissions. The DIG car accumulated with 13,000 km mileage was subject to emissions testing including gaseous emissions, particulate mass (PM) and fuel economy on a chassis dynamometer, then replaced all coking injectors with new injectors and tested emissions again.
2016-10-17
Technical Paper
2016-01-2285
Chun Guan, Xinling Li, Zhuyue Zhuang, Zhen Huang
In the present study, the effects of oxygenated fuels on particulate-phase organic pollutants including n-alkanes, polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (oxy-PAHs) were investigated on a diesel engine test bench w/o and with a particle oxidation catalyst (POC) device. Two kinds of oxygenated fuels with different oxygenated functional groups, that are biodiesel and ethanol, were selected as the target fuels to be blended with diesel by various volume percentages. POC performance was also studied to further demonstrate the effect of aftertreatments on diesel engine emissions. The results indicated that diesel-biodiesel (DB) blends presented a good linearship between alkanes suppression and blended ratios, while diesel-biodiesel-ethanol (DBE) blends only presented a better suppression on alkanes at a lower blended ratio. Meanwhile, both DB and DBE blends presented an effective suppression on particulate-phase PAHs.
2016-10-17
Technical Paper
2016-01-2286
Christophe Chaillou, Alexandre Bouet, Arnaud Frobert, Florence Duffour
Adaptation of both oil based fuel and engine technologies are key enablers to reduce the CO2 footprint as well as pollutant emissions. Recent work has demonstrated the potential of gasoline-like fuels to reduce NOx and particulate emissions when used in compression ignition engines. In addition, properties of naphtha produced directly from the atmospheric crude oil distillation process in a refinery offer significant CO2 benefits. When introducing such innovative fuel and engine, after-treatment investigations are mandatory to meet pollutant regulations. In that respect, this work focuses on investigating structure and properties of the particulates produced with naphtha fuel to validate Diesel Particulate Filter (DPF) design requirements. First, soot mass measurement technics are detailed.
2016-10-17
Technical Paper
2016-01-2287
Huifang Shao, William Lam, Joseph Remias, Joseph Roos, Seungmok Choi, HeeJe Seong
Mobile source emissions standards are becoming more stringent and particulate emissions from direct injection gasoline (DIG) engines represent a particular challenge. Gasoline particulate filter (GPF) is deemed as one possible technical solution for particulate emissions reduction. In this work, a study was conducted on eight formulations of lubricants to determine their effect on DIG engine particulate emissions and GPF performance. Ash loading tests were conducted on a 2.4L DIG engine at 1250rpm and 25% load. Engine oil injection rate was 2% of the fuel consumption rate. The matrix of eight formulations was designed with changing levels of SAP level, ZDDP level and detergent type. Comprehensive evaluations of particulates included mass, number, size distribution, composition, morphology and soot oxidation properties. GPF performance was assessed through filtration efficiency, back pressure and morphology.
2016-10-17
Technical Paper
2016-01-2301
Xiaoye Han
The homogeneous charge compression ignition (HCCI) and partially premixed combustion (PPC) of neat n-butanol have shown significant benefits in NOx and smoke emissions. However, the rapid burn rate of n-butanol results in excessive maximum pressure rise rates and limits the engine load capability. The combustion process can be slowed down by applying exhaust gas recirculation and/or later injection timing, which usually deteriorates engine efficiency and combustion stability. In this study, the neat n-butanol combustion is optimized using a multi-event combustion strategy to organize the combustion process and control the fuel burn rates for practical engine operation at extended engine loads. As indicated by the experimental results, the combustion phasing of n-butanol HCCI, enabled with port fuel injection (PFI), is generally earlier than that of n-butanol PPC, enabled with single-shot direct injection (DI), under the same engine operating conditions.
2016-10-17
Technical Paper
2016-01-2320
Tsuyoshi Asako
Ammonia Selective Catalytic Reduction (SCR) is adapted for a variety of applications to control NOx in diesel engine emission. Most commonly used catalyst for SCR in established markets is Cu-Zeolite due to excellent NOx conversion and thermal durability. However, most applications in emerging markets and certain applications in established markets utilize Vanadia SCR. The operating temperature is typically maintained below 550C to avoid vanadium sublimation due to passive regeneration of diesel particulate filter (DPF) or eliminating DPF from aftertreatment system. For DPF-less system, particulate matter (PM) standard is achievable without DPF depending on engine tuning. Further improvement of Vanadia SCR durability and NOx conversion at low exhaust gas temperatures will be required in consideration of future emission standards.
2016-10-17
Technical Paper
2016-01-2319
Kihong Kim, Rahul Mital, Takehiro Higuchi
In the previous research1), the authors discovered that the sudden pressure increase phenomenon in diesel particulate filter (DPF) was a result of soot collapse inside DPF channels. The proposed hypothesize for soot collapse was a combination of factors such as passive regeneration, high humidity, extended soak period, high soot loading and high exhaust flow rate. The passive regeneration due to in-situ NO2 and high humidity caused the straw like soot deposited inside DPF channels to take a concave shape making the collapse easier during high vehicle acceleration. It was shown that even if one of these factor was missing, the undesirable soot collapse and subsequent back pressure increase did not occur. Currently, one of the very popular NOx reduction technologies is the Selective Catalytic Reduction (SCR) on Filter which does not have any precious group metal (PGM) in the washcoat.
2016-10-17
Technical Paper
2016-01-2323
Hiroki Nakayama, Yasuharu Kanno, Makoto Nagata, Xiaolai Zheng
Recently, the regulations of exhaust gases for gasoline vehicles are become severe. To meet the regulation of exhaust gases, TWC catalysts with precious metal group were used. On the other hands, It is required the reduction the amounts of precious metal group (Pt, Pd, Rh) of TWC from a point of shortage of resource of PGM and cost issue. Conventional TWC system were composed closed couple catalyst and under floor catalyst. The closed couple TWC promoted the HC/CO oxidation and NOx reduction by CO. The under floor TWC mainly promoted the NOx reduction by CO. In this reports, to reduce the PGM amounts, cc-TWC with PGM, UF-Non PGM system were studied. Non-PGM catalyst has been developed for a gasoline combustion engine exhaust gas treatment. The after-treatment system is composed of PGM based closed couple catalyst, cc-TWC, and non-PGM catalyst in under flower position, UF-non-PGM. This UF-non-PGM is composed of Ni/CeO2 bottom layer and Zeolite based NH3-SCR top layer.
2016-10-17
Technical Paper
2016-01-2338
Himanshu Gupta, Hardik N. Lakhlani, Jayesh Telang, Abhijit Sahare
Now a day's engine hardware selection will be done with different simulation software however using thermodynamic analytical calculations and use of heat transfer principal we had co-related turbocharger performance with actual performance testing & analytical calculation for turbocharger selection. High BMEP engine with EGR technology to meet emission norms like BSIV (Equal to EUIV) requires fine tuning of engine hardware and increased the number of iterations. Cost effective turbocharger selection will support to identify possible hardware. In EGR engine high pressure ratios required for EGR drivability and higher airflow to reduce particulate matter. EGR drivability completely depends upon turbine in pressure. Small turbine housing will support for developing higher P3 however turbo speed will increases. Selection of turbocharger in primary stage with help of calculation can helps us to reduce the different iteration trials and reduced front loading in stringent time line.
2016-10-17
Technical Paper
2016-01-2211
Peter Larsson, Will Lennard, Oivind Andersson, Per Tunestal
Increased research is being driven by the automotive industry facing challenges, requiring to comply with both current and future emissions legislation, and to lower fuel consumption. The reason for this legislation is to restrict the harmful pollution which every year causes 3.3 million premature deaths worldwide. One factor that causes this pollution is NOx emissions. NOx emission legislation has been reduced from 8 g/kWh (Euro 1) down to 0.4 g/kWh (Euro 6) and recently new legislation for ammonia slip results in even more challenge for the SCR technology. In order to achieve a good NOx conversion together with a low slip of ammonia, small droplets of UREA solution need to be injected which can be rapidly evaporated and mixed into the flow of exhaust gases.
2016-10-17
Technical Paper
2016-01-2212
Peter Larsson, Will Lennard, Jessica Dahlstrom, Oivind Andersson, Per Tunestal
Yearly 3.3 million premature deaths occur worldwide due to air pollution and NOx pollution counts for nearly one seventh of those. This makes exhaust after-treatment a very important research and hase caused the permitted emission levels for NOx to decrease to very low levels, for EURO 6 only 0.4 g/kWh. Recently new legislation on ammonia slip with a limit of 10 ppm NH3 has been added which makes the SCR-technology more challenging. This technology injects small droplets of an aqueous UREA solution into the stream of exhaust gases and through a catalytic reaction within the SCR-catalyst, NOx is converted into Nitrogen and Water. To enable the catalytic reaction the water content in the UREA solution needs to be evaporated and the ammonia molecules need to have sufficient time to mix with the gases prior to the catalyst.
2016-10-17
Technical Paper
2016-01-2213
Tomoaki Ito, Makoto Nagata
Diesel exhaust emission control systems often contain DOC (Diesel Oxidation Catalyst) + CSF (Catalyzed Soot Filter) components. In this system PM (particulate matter) is filtered and accumulated in the CSF and such filtered PM is periodically combusted by supplying heat to the CSF. The heat to CSF is generated within the DOC by an exothermic reaction with extra fuel supplied to the DOC. Here the exothermic performance of DOC depends on not only the active catalytic site (such as Pt and/or Pd) but also on the characteristics of the porous material supporting the precious metals. Various properties of Al2O3, i.e. pore diameter, pore volume, BET, acidity, basicity and the Ea (activation energy) of fuel combustion, used in DOCs and PGM particle size of each DOC were measured. The fuel combustion performance of each DOC was evaluated by diesel engine bench.
2016-10-17
Technical Paper
2016-01-2214
Teuvo Maunula, Thomas Wolf
The emission regulations for mobile on- and off-road applications are becoming stricter in Euro 6/Stage 5 and beyond levels and require the use of SCR for NOx and diesel particulate filter (DPF) for PM removal. The presence of wall-flow filter with active regeneration creates a risk of thermal deactivation of SCR catalyst in the aftertreatment system (ATS). The thermal and chemical durability of Cu- and Fe-SCR catalysts were screened and developed to stand these conditions. The performance of catalysts were investigated with laboratory simulations and engine-bench equipments. New Cu-SCR catalysts have a very high low-temperature SCR activity and a low dependency on NO2 promotion. Developed Fe-SCR catalysts showed also an improved low temperature activity and durability but were more dependant on NO2 concentration too. Low N2O formation with Cu-SCR catalyst is a key factor to minimize green house gas emissions.
2016-10-17
Technical Paper
2016-01-2238
Kazunari Kuwahara, Tadashi Matsuo, Yasuyuki Sakai, Yoshimitsu Kobashi, Tsukasa Hori, Eriko Matsumura, Jiro Senda
Normal tridecane, a low-boiling-point component of gal oil, has been employed as a single-component fuel for diesel combustion model experiments. However, no reaction mechanism for normal tridecane has been applied to three-dimensional modeling to reproduce experimental resulsts. A detailed reaction mechanism for normal tridecane generated by KUCRS (Knowledge-basing Utilities for Complex Reaction Systems), contains 1493 chemical species and 3641 elementary reactions. Reaction paths during ignition process computed using the detailed mechanism, were analyzed with the initial temperatures of 650 K, 850 K and 1100 in the tau1 dominant, negative temperature coefficient and non-tau1 regions, respectively. Based on knowledge derived from the reaction path analysis, a reduced reaction mechanism containing 49 species and 85 reactions, was generated and validated.
2016-10-17
Technical Paper
2016-01-2241
Zhongpan ZHU, Rui Lin, Aimin Du
Researches of Atkinson cycle realized by LIVC (Late Intake Valve Closing) strategy in internal combustion engines show that the extended expansion gasoline engine has a better fuel economic performance compared to traditional gasoline engines. However, LIVC has an intrinsic drawback in that combustion performance deteriorates due to the decline in the effective compression ratio (CR). In this paper, EGR (Exhaust Gas Recirculation) was adapted to improve LIVC strategy for better engine performance. Different EGR and LIVC strategies was simulated by a test verified 1-D numerical model which was set in GT-power software, and the results show that LIVC strategy combined proper EGR rate have good potential in both dynamic and fuel economic improvement.
2016-10-17
Technical Paper
2016-01-2242
Dimitris Assanis, Nayan Engineer, Paul Neuman, Margaret Wooldridge
Lean burn combustion strategies are an attractive option to increase the thermal efficiency of gasoline spark ignition internal combustion engines, but engine design remains challenging due to the lean flammability limits of the fuel/air mixture. A new engine design is proposed in this work where fuel is injected into the main combustion chamber and spark electrodes are located in the pre-chambers. The objective of this computational study was to evaluate the feasibility of several engine design configurations combined with fuel injection strategies to create local fuel/air mixtures in the pre-chambers above the ignition and flammability limits, while maintaining lean conditions in the main combustion chamber.
2016-10-17
Technical Paper
2016-01-2249
Akash Gangwar, Abhinav Bhardawaj, Ramesh Singh, Naveen Kumar
Enhancement of combustion behavior of conventional liquid fuel using nanoscale materials of different properties is an imaginative and futuristic topic. This experiment is aimed to evaluate the performance and emission characteristics of a diesel engine when lade with nanoparticles of Cu-Zn alloy. The previous work reported the effect of metal/metal oxide or heterogeneous mixture of two or more particles; less work had been taken to analyze the homogeneous mixture of metals. This paper includes fuel properties such as density, kinematic viscosity, calorific value and performance measures like brake thermal efficiency (BTE), brake specific fuel consumption (BSFC) and emission analysis of NOx, CO, CO2, HC. For the same solid concentration, nano-fuel is compared with base fuel at different engine loads; and its effect when lade at different concentrations.
2016-10-17
Technical Paper
2016-01-2185
Jialin Liu, Hu Wang, Zunqing Zheng, Zeyu Zou, Mingfa Yao
In this work, both the ‘SCR-only’ and ‘EGR+SCR’ technical routes are compared and evaluated after the optimizations of both injection strategy and turbocharging system over the World Harmonized Stationary Cycle (WHSC) in a heavy duty diesel engine. Moreover, the emissions and fuel economy performance of different turbocharging systems, including wastegate turbocharger (WGT), variable geometry turbocharger (VGT), two-stage fixed geometry turbocharger (WGT+FGT) and two-stage variable geometry turbocharger (VGT+FGT), are investigated over a wide EGR range. The NOx reduction methods and EGR control strategies for different turbocharger systems are proposed to improve the fuel economy. The requirement of turbocharging system at various NOx emissions and their potential to meet future stringent emission regulations are also discussed in this paper.
2016-10-17
Technical Paper
2016-01-2216
Brad Richard, Martha Christenson, Deborah Rosenblatt, Aaron Conde
Five Ford Transit Connect vans, operating on alternative fuels and propulsion systems, were tested on a chassis dynamometer. The vehicles were powered with petrol, low blend ethanol (E10), compressed natural gas (CNG), liquefied petroleum gas (LPG), and an electric battery. Four test cycles were used representing city driving and cold-start (FTP-75), aggressive high speed driving (US06), free flow highway driving (HWFCT), and a combination of urban, rural, and motorway driving (WHVC). Tests were performed at temperatures of 22°C, with select tests at -7oC and -18°C. Exhaust emissions were measured and characterized including, on all cycles, CO, NOX, THC, TPM (except on WHVC), and CO2. On the FTP-75, WHVC, and US06 cycles additional exhaust emission characterization included N2O, and CH4. On the FTP-75 and WHVC, carbonyl compounds and volatile organic compounds (VOCs) were also characterized.
2016-10-17
Technical Paper
2016-01-2282
Toru Uenishi, Eijiro Tanaka, TAKAO FUKUMA, Jin Kusaka, Yasuhiro Daisho
Experimental and numerical studies were conducted on diesel particulate filter (DPF) under different Particulate Matter (PM) loading and DPF regeneration conditions.Pressure losses across DPF loaded with PM having different mean particle diameters and regenerated with introducing hot gas created in Diesel Oxidation Catalyst(DOC)with oxidized hydrocarbon injected by fuel injector place on exhaust gas pipe were measured by introducing exhaust gases from a 2.2 liter inline four- cylinder, TCI diesel engine designed for use in passenger cars.Pressure drops across DPF loaded with PM having larger mean particle diameters expressed smaller than smaller mean particle diameters in PM loading phase.Meanwhile, the combustion amount and the decrease of pressure losses across DPF loaded with PM having larger mean particle diameters expressed smaller than smaller mean particle diameters in DPF regeneration phase.A mechanistic hypothesis was then proposed to explain the observed trends,accounting for the effects of the soot loading regime in the wall and the soot cake layer on the pressure drop.This hypothesis was used to guide the development and validation of a numerical model for predicting the pressure drop in the DPF.The relationship between the permeability and the porosity of the wall and soot cake layer was modeled under various soot loading conditions.The percolation coefficient at which the soot filtering regime changed from wall trapping to cake layer trapping was also determined by considering the filtering efficiency.The activation energy and exponential factor in the reaction rate constant was calibrated by each the mean diameter of secondary soot particles.The model was validated by comparing its output to the results of experimental test cell studies and used to analyze transport phenomena in particular filters.
2016-10-17
Technical Paper
2016-01-2288
Sam Shamun, Mengqin Shen, Bengt Johansson, Martin Tuner, Joakim Pagels, Anders Gudmundsson, Per Tunestal
The focus has recently been directed towards the engine out soot from Diesel engines. Running the engine in PPC mode has a proven tendency of reducing these emissions significantly. In addition to combustion strategy, several studies have suggested that using alcohol fuels will aid in reducing soot emissions to ultra-low levels. This study analyzes and compares the characteristics of PM emissions from naphtha gasoline PPC, ethanol PPC, methanol PPC and methanol diffusion combustion in terms of soot mass concentration, particle size and distribution in a single cylinder Scania D13 engine, while varying the intake O2. Intake temperature and injection pressure sweeps were also conducted. The fuels emitting the highest amount of particles were gasoline followed by methanol. The two alcohols tested emitted nucleation mode particles only, whereas gasoline emitted accumulation mode particles as well.
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