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Viewing 1 to 30 of 15125
2017-10-08
Technical Paper
2017-01-2301
Hongli Gao, Fujun Zhang, Wenwen Zeng, Tianpu Dong, Zhengkai Wang
Abstract The electronic control of direct injection fuel system, which could improve engine fuel efficiency, dynamics and engine emission performance through good atomization, precise control of fuel injection time and improvement of fuel-gas mixture, is the key technology to achieve the stratified combustion and lean combustion. In this paper, a direct injection injector that based on voice coil motor was designed aiming at the technical characteristics of one 800cc two-stroke cam-less engine. Prior to a one - dimensional simulation model of injector was established by AMEsim and the maximal fuel injection demand was met via the optimization of the main parameters of the injector, the structure of the voice coil motor was optimized by magnetic equivalent circuit method. After that, the maximal flow rate of the injector was verified by the injector bench test while the atomization characteristic of the injector was verified by using a high-speed camera.
2017-10-08
Technical Paper
2017-01-2323
Lei Li, Kai Sun, Jianyu Duan
Abstract Butanol is a promising alcohol fuel. Previous studies on combustion and diesel engines showed different trends in sooting tendencies of the butanol isomers (n-butanol, iso-butanol, sec-butanol and tert-butanol).The impact of butanol isomers on the particulate emissions of GDI (Gasoline Direct Injection) engines, however, has not been reported. This work examines the combustion performance and particle number emissions of a GDI engine fueled with gasoline/butanol blends in steady state modes. Each isomer was tested at blend ratios from 10% to 50% by volume. Spark timings for all the fuels are set to obtain the maximum break torque (MBT), i.e. the MBT spark timings. Results show that the particle number concentration is reduced significantly with increasing butanol content for all the isomers.
2017-10-08
Technical Paper
2017-01-2312
Raouf Mobasheri, Rahman Akbari
Abstract The scope of this work is to investigate the simultaneous effects of injection pressure and Exhaust Gas Recirculation (EGR) on mixture formation and engine performance in a High Speed Direct Injection (HSDI) diesel engine. For this, the computational results have been firstly compared to the measured data and a good agreement has been achieved in order to predict the in-cylinder pressure, heat release rate and the amount of NOx and soot emissions. Then, various injection pressures have been studied to explore its benefits to achieve the low exhaust emission at different EGR rates. The results show, while no EGR has been applied, decreasing the nozzle diameter causes the reduction of Indicate Specific Fuel Consumption (ISFC) with an increase in Indicated Mean Effective Pressure (IMEP).
2017-10-08
Technical Paper
2017-01-2322
Tankai Zhang, Karin Munch, Ingemar Denbratt
Abstract Reducing emissions and improving efficiency are major goals of modern internal combustion engine research. The use of biomass-derived fuels in Diesel engines is an effective way of reducing well-to-wheels (WTW) greenhouse gas (GHG) emissions. Moreover, partially premixed combustion (PPC) makes it possible to achieve very efficient combustion with low emissions of soot and NOx. The objective of this study was to investigate the effect of using alcohol/Diesel blends or neat alcohols on emissions and thermal efficiency during PPC. Four alcohols were evaluated: n-butanol, isobutanol, n-octanol, and 2-ethylhexanol. The alcohols were blended with fossil Diesel fuel to produce mixtures with low cetane numbers (26-36) suitable for PPC. The blends were then tested in a single cylinder light duty (LD) engine. To optimize combustion, the exhaust gas recirculation (EGR) level, lambda, and injection strategy were tuned.
2017-10-08
Technical Paper
2017-01-2329
Xiao Ma, Yue Ma, Shuaishuai Sun, Shi-Jin Shuai, Zhi Wang, Jian-Xin Wang
Abstract Polyoxymethylene dimethyl ethers (PODEn) are promising alternative fuel candidates for diesel engines because they present advantages in soot reduction. This study uses a PODEn mixture (contains PODE3-6) from mass production to provide oxygen component in blend fuels. The spray combustion of PODEn-diesel bend fuels in a constant volume vessel was studied using high speed imaging, PLII-LEM and OH* chemiluminescence. Fuels of several blend ratios are compared with pure diesel. Flame luminance data show a near linear decrease tendency with the blend ratio increasing. The OH* images reveal that the ignition positions of all the cases have small differences, which indicates that using a low PODEn blend ratio of no more than 30% does not need significant adjustment in engine combustion control strategies. It is found that 30% PODEn blended with diesel (P30) can effectively reduce the total soot by approximately 68% in comparison with pure diesel.
2017-10-08
Technical Paper
2017-01-2328
Yuanxu Li, Karthik Nithyanandan, Zhi Ning, Chia-Fon Lee, Han Wu
Abstract Bio-butanol has been widely investigated as a promising alternative fuel. However, the main issues preventing the industrial-scale production of butanol is its relatively low production efficiency and high cost of production. Acetone-butanol-ethanol (ABE), the intermediate product in the ABE fermentation process for producing bio-butanol, has attracted a lot of interest 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. If ABE could be directly used for clean combustion, the separation costs would be eliminated which save an enormous amount of time and money in the production chain of bio-butanol.
2017-10-08
Technical Paper
2017-01-2339
Pi-qiang Tan, Yuan Li
Abstract With increasingly severe atmospheric environmental problems, diesel car emissions have attracted broad attention for its main contribution to air pollutant. Alternative fuels become a hot research point in vehicle for rapidly consuming of fossil oil resources. Biodiesel and GTL (gas to liquid) fuels are two typical alternative fuels for diesel fuel. Low blend ratio (≤10%) biodiesel and GTL fuels can be used in a diesel engine without modifying the engine’s configuration. It is important to investigate the difference of low blend ratio biodiesel and GTL fuels used in the same diesel car and to find the optimum one. Gaseous and particle emissions from a light duty diesel car with B10 (10% biodiesel from cooking oil +90% diesel, v/v) and G10 (10% GTL fuel +90% diesel, v/v) was investigated. It was equipped with high pressure common rail system, cooled EGR and DOC and was tested on a chassis dynamometer under NEDC mode.
2017-10-08
Technical Paper
2017-01-2340
Shashank Mishra, Anand Krishnasamy
Abstract Biodiesel is a renewable, carbon neutral alternative fuel to diesel for compression ignition engine applications. Biodiesel could be produced from a large variety of feedstocks including vegetable oils, animal fats, algae, etc. and thus, vary significantly in their composition, fuel properties and thereby, engine characteristics. In the present work, the effects of biodiesel compositional variations on engine characteristics are captured using a multi-linear regression model incorporated with two new biodiesel composition based parameters, viz. straight chain saturation factor (SCSF) and modified degree of unsaturation (DUm). For this purpose, biodiesel produced from seven vegetable oils having significantly different compositions are tested in a single cylinder diesel engine at varying loads and injection timings. The regression model is formulated using 35 measured data points and is validated with 15 other data points which are not used for formulation.
2017-10-08
Technical Paper
2017-01-2182
Xikai Liu, Xingyu Liang, Yonge Wu, Yuesen Wang
According to the study of the soot emission in marine diesel, ,a new reduced mechanism for n-heptane was constructed to describe the combustion process in diesel engine by using sensitivity analysis.Furthermore,verifying the ignition delay time,the laminar flame speed,the flame propagation distance and species profiles in combustion process by using Chemkin Pro in different pressure(13.5atm and 42 atm),initial temperatures and equivalence ratio(0.5 and 1.0).Then,compare the simulated result with the experiment data and the simulated result by using LLNL(lawrence livermore national laboratory)detail mechanism and SKLE(state key laboratory of engine)mechanism.It is demonstrated that the reduced mechanism can not describe the ignition delay time in low temperature.And then,the reduced mechanism was adjusted and optimized to make it more close to the experiment data,and the reduced mechanism were able to predict ignition delay time,laminar flame speed,flame propagation distance and species profiles.The final reduced n-heptane mechanism are more compact compare with the current detailed mechanisms in literature.Thus,this reduced n-heptane mechanism can reduce the pressure of calculation and save the calculation time.
2017-10-08
Technical Paper
2017-01-2190
Alessandro D'Adamo, Marco Del Pecchia, Sebastiano Breda, Fabio Berni, Stefano Fontanesi, Jens Prager
CFD simulations of reacting flows are fundamental investigation tools used to predict combustion behaviour and pollutants formation in modern spark-ignition internal combustion engines. Most of the flamelet-based combustion models adopted in current simulations use the fuel/air/residual laminar flame speed as a background to predict the turbulent flame speed. This in turn is a fundamental requirement to model the effective burn rate. The consolidated approach in engine combustion simulations relies on the adoption of empirical correlations for laminar flame speed, which are derived from fitting activity of combustion experiments. However, these last are conducted at largely different pressure and temperature ranges from those encountered in engines: for this reason, correlation extrapolation at engine conditions is inevitably accepted and relevant differences between proposed correlations emerge even for the same fuel and conditions.
2017-10-08
Technical Paper
2017-01-2194
Mateusz Pucilowski, Mehdi Jangi, Sam Shamun, Martin Tuner, Xue-Song Bai
Experimental heavy-duty DICI methanol engine is studied under high compression ratio conditions (CR=27). The fuel is injected with common-rail injector close to the top-dead-center (TDC) position with three different injector pressures, leading to a spray formation causing a so called wall-wetting. Numerical simulations using RANS/LPT/WSR and PDF models are employed to investigate the local conditions of the injection and combustion process. The CFD results are compared with the pressure trace and emissions from the metal engine experiment. It is shown that the simulations captured the same trend of increased amount of unburned hydrocarbons at higher injection pressures. Moreover, the intake temperature adjustments were required to correctly capture the ignition delay time when WSR model was used, whereas with the PDF method such adjustments were not needed.
2017-10-08
Technical Paper
2017-01-2200
Peter Priesching, Mijo Tvrdojevic, Ferry Tap, Casper Meijer
Turbulent combustion modeling in a RANS or LES context imposes the challenge of closing the chemical reaction rate on the sub-grid level. Many turbulent combustion models exist in literature. Such turbulent models have as their two main ingredients sources from chemical reactions and turbulence-chemistry interaction. The various combustion models then differ mainly by how the chemistry is calculated (level of detail, canonical flame model) and on the other hand how turbulence is assumed to affect the reaction rate on the sub-grid level (turbulence-chemistry interaction - TCI). In this work, an advanced combustion model based on tabulated chemistry is applied for 3D CFD modeling of Diesel engine cases. The combustion model is based on the Flamelet Generated Manifold (FGM) chemistry reduction technique. The underlying chemistry tabulation process uses auto-ignition trajectories of homogeneous fuel/air mixtures, which are computed with detailed chemical reaction mechanisms.
2017-10-08
Technical Paper
2017-01-2405
Christophe Chaillou, Alexandre Bouet, Arnaud Frobert, Florence Duffour
Abstract Fuels from crude oil are the main energy vector used in the worldwide transport sector. But conventional fuel and engine technologies are often criticized, especially Diesel engines with the recent “Diesel gate”. Engine and fuel co-research is one of the main leverage to reduce both CO2 footprint and criteria pollutants in the transport sector. Compression ignition engines with gasoline-like fuels are a promising way for both NOx and particulate emissions abatement while keeping lower tailpipe CO2 emissions from both combustion process, physical and chemical properties of the low RON gasoline. To introduce a new fuel/engine technology, investigation of pollutants and After-Treatment Systems (ATS) is mandatory. Previous work [1] already studied soot behavior to define the rules for the design of the Diesel Particulate Filter (DPF) when used with a low RON gasoline in a compression ignition engine.
2017-10-08
Technical Paper
2017-01-2410
Ji Gao, Tie Wang, Dandan Sun, Jing Qiao, Yizhuo Feng
Abstract As the explosion proof diesel engine (EPD) of underground trackless tyred vehicle dynamic mechanical device, due to its good dynamic and economic performance, the diesel has been widely applied. The flame arrester can prevent the exhaust system from tempering, but the increased resistance will seriously affect the performance of diesel. Through the comparison of the CFD-FLUENT fluid simulation on flow and pressure field, the results show that the corrugated flame arrester performs better on reducing the exhaust back pressure than flat flame arrester and ensures the explosion-proof effect. The bench test of explosion proof diesel engine on intake and exhaust system is conducted, analysing the effect of the exhaust resistance under different speeds of diesel engine on the power, economy and emission of TY4100QFB type diesel engines with equivalent flow area , different specifications of flat versus corrugated flame-arrester in the course of external characteristics.
2017-10-08
Technical Paper
2017-01-2363
Murugesa Pandian M, Anand Krishnasamy
The major limitations in a conventional high temperature diesel combustion are higher oxides of nitrogen (NOx) and particular matter (PM) emissions and a trade-off between them. Advanced low temperature combustion (LTC) strategies are proposed to simultaneously reduce NOx and PM emissions to near zero levels along with higher thermal efficiencies. Various LTC strategies including Premixed Charge Compression Ignition (PCCI), Homogenous Charge Compression Ignition (HCCI), Reactivity Controlled Compression Ignition (RCCI), Stratified Charge Compression Ignition (SCCI) and High Efficiency Clean Combustion (HECC) are proposed so far to achieve near zero NOx and PM emissions along with higher thermal efficiencies. Each of these LTC strategies have their own advantages and limitations interms of precise ignition control, achievable load range and higher unburned emissions.
2017-10-08
Technical Paper
2017-01-2364
Jiaqiang Li, Yunshan Ge, Chao He, Jianwei Tan, Zihang Peng, Zidi Li, Wei Chen, Shijie Wang
Urea selective catalytic reduction 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 selective catalytic reduction process. The thermolysis and hydrolysis of urea produces reducing agent ammonia and provides to catalysts to reduce 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℃. For preventing deposits formation, the aqueous urea solution is difficult to be injected into the exhaust gas stream at temperature below 200℃. The aqueous urea solution used as reducing agent precursor is the main obstacle for achieving high deNOx performances at low temperature conditions.
2017-10-08
Technical Paper
2017-01-2458
Mohamed Awadallah, Peter Tawadros, Paul Walker, Nong Zhang
Driven by stricter mandatory regulations on fuel economy improvement and emissions reduction, market penetration of electrified vehicles will increase in the next 10 years, among which mild hybrid will become a leading sector in growth. Researchers forecast the sales of mild hybrid vehicles will reach 1.4 million units per year by 2020, and 7 million units by 2024. The high cost of HEVs has somewhat limited their widespread adoption, especially in developing countries. Conversely, it is these countries that would benefit most from the environmental benefits of HEV technology. Compared to a full hybrid, a plug‐in hybrid or an electric vehicle, a mild hybrid system stands out due to its maximum benefit/cost ratio. As part of our ongoing project to develop a mild hybrid system for these markets to improve the drive performance and efficiency. High power density ultra-capacitors are incorporated for fast charging and discharging during the acceleration and other operations.
2017-10-08
Technical Paper
2017-01-2371
Hiroki Kambe, Naoto Mizobuchi, Eriko Matsumura
Diesel Particulate filter (DPF) is installed as after treatment device of exhaust gas in diesel engine, and it collects Particulate Matter (PM). However, as the operation time of engine increases, the PM is accumulated in the DPF, resulting in deterioration of PM collection efficiency and increase in pressure loss. Therefore, Post injection has been attracted attention as the DPF regeneration method for burning and removing PM in the DPF. But, Post injection causes oil dilution when fuel is injected at the middle to late stage of expansion stroke. Oil dilution are concern to decrease the stroke lubricity of piston movement and the thermal efficiency. In order to estimate deposition amount of fuel spray that influences oil film, we should elucidate spray impingement behavior on wall surface of oil film, to research more from the behavior of in-cylinder spray during post injection.
2017-10-08
Technical Paper
2017-01-2369
Prakash Arunachalam, Martin Tuner, Per Tunestal, Marcus Thern
Humid air motor (HAM) is an engine operated with humidified inlet charge. System simulations study on HAM showed the waste heat recovery potential over a conventional system. An HAM setup was constructed, to comprehend the potential benefits in real-time, 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 provided the potential benefits of each system. Exhaust heat was used for partial humidification process. Results show that HAM operation, without compromising on efficiency, reduces NOx and soot significantly over the engine operated without EGR.
2017-10-08
Technical Paper
2017-01-2368
Wenji Song, Weiyong Tang, Bob Chen
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 fration (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 DOC+V-SCR 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.
2017-10-08
Technical Paper
2017-01-2367
Ganesan Mahadevan, Sendilvelan Subramanian
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
Because of the increased use of gasoline direct engine (GDI) in 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, 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. The details of the study are presented in the paper.
2017-10-08
Technical Paper
2017-01-2365
Murugesa Pandian M, Anand Krishnasamy
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
2017-01-2401
Elana Chapman, Pat Geng, Yaowei Zhao, Susan Zhang, JunJun Ma, Jianqiang Gong
The impact of gasoline compositions to vehicle particular emission response have been widely investigated and documented with recently proposed so called Particulate Matter Index (PMI) and Particulate Evaluation Index (PEI). Vehicle PM/PN data has demonstrated correlations of the indices to vehicle response. In previous paper, global assessment with PEI on fuel sooting tendency was presented. With increasing air pollution concern and ever stringent emission requirements in China, both OEMs and oil industries are facing new challenge. Emission control requires systematic approach on both fuel and vehicle. This paper will focus on China market gasoline on fuel’s sooting tendency. Additional China vehicle response with ranges of PEI fuels are presented. In addition to PEI index, other fuel properties in gums, final boiling, aromatics, and fuel detergency are also reviewed
2017-10-08
Journal Article
2017-01-2400
Yanlong Wu, Jason Ferns, Hu Li, Gordon Andrews
Hydrogenated vegetable oil (HVO) diesel fuels have potential to provide reduced carbon footprint in diesel engines and reduce exhaust emissions. Therefore it is a strong candidate for transport and diesel powered machines including electricity generators and other off-road machines. In this research, a waste cooking oil derived HVO diesel was investigated for its combustion performance including ignition delay and heat release, and particulate number emissions including size segregated values. The results were compared to the standard petroleum diesel. A 3 litre direct injection intercooled IVECO diesel engine equipped with EGR was used which has a maximum power output of 96kW and is EURO5 emission compliant. The engine was equipped with an integrated DOC and DPF aftertreatment system. Both the upstream and downstream of the aftertreatment emissions were measured. The tests were conducted at different RPM and loads at steady state conditions.
2017-10-08
Technical Paper
2017-01-2397
Zhan Gao, Lei Zhu, Xinyao Zou, Chunpeng Liu, Zhen Huang
Biodiesel is a potential alternative fuel which can meet the growing need for sustainable energy. Partially premixed compression ignition (PPCI) is an important low-temperature combustion strategy to reduce NOx and soot emission of diesel engines. To investigate partial premixing impact on particle formation in flames of biodiesel or biodiesel surrogates, an experimental study was performed to compare the soot morphology and nanostructure evolution in laminar co-flow methyl decanoate non-premixed flame (NPF) and partially premixed flame (PPF). The thermophoretic sampling technique was used to capture particles along flame centerlines. Soot morphology information and volume fraction were obtained from TEM analysis and nanostructure features were evaluated by HR-TEM. With primary equivalence ratio of 19, gas temperature of PPF is higher along flame centerline compared with NPF. The results show an initially stronger sooting tendency in PPF at lower positions.
2017-10-08
Journal Article
2017-01-2375
Akihiro Niwa, Shogo Sakatani, Eriko Matsumura, Takaaki Kitamura
Diesel engine has low carbon emissions and high fuel efficiency. However, diesel engine needs to reduce both Nitrogen Oxide (NOx) and Particulate matters (PM). To meet the demand of strict exhaust gas regulation, after-treatment device is required. Therefore, urea SCR (Selective Catalytic Reduction) system is used to clean NOx in diesel engine exhaust gas. In urea SCR system, it is necessary to inject the urea water solution upstream the SCR catalyst. And, it can reduce NOx applying the generated ammonia (NH3) by urea thermolysis and isocyanic acid (HNCO) hydrolysis. In this study, it focused on urea SCR system. The spray behavior injected in tail-pipe can be divided into the regime of a free spray, an impingement spray, an evaporation of liquid film and a separation droplets, and an urea water solution dispersion. Also, in each region, after evaporation of H2O in urea water solution completely, NH3 is generated by urea thermolysis and HNCO hydrolysis.
2017-10-08
Technical Paper
2017-01-2373
Jun Kaniyu, Shogo Sakatani, Eriko Matsumura, Takaaki Kitamura
Diesel Particulate Filter (DPF) is a very effective aftertreatment device to limit particulate emissions from diesel engines. As the amount of soot collected in the DPF increases, the pressure loss increases and the purification rate decreases. Therefore, DPF regeneration needs to be performed. Injected fuel into the exhaust line upstream of the Diesel Oxidation Catalyst (DOC), hydrocarbons are oxidized on the DOC, which increases the exhaust gas temperature at the DPF inlet. Also, it is necessary that the injected fuel is completely vaporized before entering the DOC, and uniformly mixed with the exhaust gases in order to make the DOC work efficiency and durably. However, ensuring complete evaporation and an optimum mixture distribution in the exhaust line are challenging. Therefore, it is important that the fuel spray feature are grasped to perform DPF regeneration effectively. The purpose of this study is the constructing a simulation model.
2017-10-08
Technical Paper
2017-01-2383
Guoyang Wang, Jun Zhang, Bo Yang, Chuandong Li, Shi-Jin Shuai, Shi Yin, Meng Jian
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
2017-01-2381
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 used model 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.
Viewing 1 to 30 of 15125