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Technical Paper
2014-10-13
Jim Barker, Jacqueline Reid, Colin Snape, David Scurr, William Meredith
Abstract Since 2009, there has been a rise in deposits of various types found in diesel fuel injection systems. They have been identified in the filter, the injector tip and recently inside the injector. The latter internal diesel injector deposits (IDIDs) have been the subject of a number of recent publications, and are the subject of investigations by CRC (Central Research Council Diesel Performance Group-Deposit Panel Bench/ Rig Investigation sub panel) in the US and CEN (Committee European de Normalisation TC19/WG24 Injector Deposit Task Force) and CEC (Coordinating European Council TDFG-110 engine test) in Europe. In the literature one of the internal injector deposit types, amide lacquers, has been associated with a poorly characterised noncommercial low molecular weight polyisobutylene succinimide detergent which also lacked provenance. This work will describe a well characterised non-commercial low molecular weight polyisobutylenesuccinimide, the engine tests associated with it and the spectroscopic analysis of the needle of the resultant stuck injectors.
Technical Paper
2014-10-13
Norifumi Mizushima, Daisuke Kawano, Hajime Ishii, Yutaka Takada, Susumu Sato
Abstract Widespread use of biofuels for automobiles would greatly reduce CO2 emissions and increase resource recycling, contributing to global environmental conservation. In fact, activities for expanding the production and utilization of biofuels are already proceeding throughout the world. For diesel vehicles, generally, fatty acid methyl ester (FAME) made from vegetable oils is used as a biodiesel. In recent years, hydrotreated vegetable oil (HVO) has also become increasingly popular. In addition, biomass to liquid (BTL) fuel, which can be made from any kinds of biomass by gasification and Fischer-Tropsch process, is expected to be commercialized in the future. On the other hand, emission regulations in each country have been tightened year by year. In accordance with this, diesel engines have complied with the regulations with advanced technologies such as common-rail fuel injection system, high pressure turbocharger, EGR and aftertreatment system. Unfortunately, the engine control system with these advanced technologies is adapted to conventional diesel fuels.
Technical Paper
2014-10-13
Jonathan Stewart, Roy Douglas, Alexandre Goguet, Cristina Elena Stere, Luke Blades
Abstract One of the most critical aspects in the development of a kinetic model for automotive applications is the method used to control the switch between limiting factors over the period of the chemical reaction, namely mass transfer and reaction kinetics. This balance becomes increasingly more critical with the automotive application with the gas composition and gas flow varying throughout the automotive cycles resulting in a large number of competing reactions, with a constantly changing space velocity. A methodology is presented that successfully switches the limitation between mass transfer and reaction kinetics. This method originally developed for the global kinetics model using the Langmuir Hinshelwood approach for kinetics is presented. The methodology presented is further expanded to the much more complex micro-kinetics approach taking into account various kinetic steps such as adsorption/desorption and surface reactions. The dual kinetic model is then tested against experimental data from two lab reactors one using spatially resolved data and one using the conventional end pipe analysis.
Technical Paper
2014-10-13
Anders Widd, Magnus Lewander
Abstract The Selective Catalytic Reduction (SCR) catalyst with ammonia as reducing agent plays a central role in today's exhaust after-treatment systems for heavy-duty vehicles and there is a wide selection of possible catalytic materials to use. In order to facilitate the design of future catalysts, several aspects of the materials must be evaluated both in steady-state and transient operation. To this end, this paper presents a methodology for comparing the dynamic properties of different catalysts using full-size engine testing. The studied characteristics include the ammonia storage capacity, the effect of starting with an empty catalyst, the transient response to temperature gradients and changes in the urea dosing level. The temperature response is of particular importance in transient operation, where temperature increases may lead to substantial ammonia slip. A vanadium catalyst is compared to a Cu-SAPO-34 catalyst, and they show significant differences in their dynamic response.
Technical Paper
2014-10-13
Rong Ma, Chao He, Jiaqiang Li
A simulation model of catalyzed diesel particulate filter (CDPF) is established based on the CFD software FIRE and has been validated through a series of experimental comparison. This model simulates the CDPF continuous regeneration process, and the factors that influence the exhaust NO2 concentration from CDPF including oxygen concentration, exhaust temperature, space velocity, proportion of NO2/NOX and soot mass fraction are studied. The results show that the higher oxygen concentration causes an increase in NO2/NOX. The NO2/NOX is significantly increased when the exhaust temperature is about 350 °C based on the simulation conditions when the inlet oxygen concentration is at 5.79% and the space velocity is 7s−1. The space velocity in a certain degree leads to higher NO2/NOX. For the soot mass, there is no significant influence of increasing proportion of the NO2/NOX.
Technical Paper
2014-10-13
Kotaro Tanaka, Masatoshi Takano, Shuji Iimura, Kai Miyamura, Mitsuru Konno
Abstract Recently, highly sensitive near-IR laser absorption spectrometers have been employed to measure ammonia (NH3) emissions. These instruments allow in-situ measurements of highly time-resolved NH3 emission levels in automobile exhaust. However, the effect of the automobile exhaust CO2 in NH3 measurements has not been studied in detail. Because the CO2 concentration in automobile exhaust is 2 to 3 orders of magnitude higher than the NH3 concentration, there is a possibility that spectral overlap by CO2 lines and/or the spectral broadening of NH3 by CO2 could affect the measured NH3 levels. This study had two major objectives. First, the effect of CO2 on the measured NH3 concentration was assessed using our developed near-IR laser absorption spectrometer. The second objective was to provide on-board NH3 measurements in the hybrid gasoline automobile exhaust using the developed spectrometer. As a result, the CO2 in automobile exhaust was found to affect the measured NH3 concentration.
Technical Paper
2014-10-13
Barouch Giechaskiel, Giorgio Martini
Abstract In the current heavy-duty engine and light-duty diesel vehicle exhaust emission legislation Particle Number (PN) limits for solid particles >23 nm are prescribed. The legislation was extended to include Gasoline Direct Injection (G-DI) vehicles since September 2014 and will be applied to Non-Road Mobile Machinery engines in the future. However there are concerns transferring the same methodology to other engine technologies, where higher concentration of sub-23 nm particles might exist. This paper focuses on the capabilities of existing PN measurement equipment on measuring solid particles smaller than 23 nm. More specifically, it is investigated: 1) whether it is feasible to easily modify existing systems to measure lower particle sizes, 2) whether all volatile particles can be removed efficiently in the PN measurement systems, 3) whether any artifacts happen in the PN systems (e.g. formation of non-volatile particles due to pyrolysis), and 4) whether by lowering the lower size the measurement uncertainty increases significantly.
Technical Paper
2014-10-13
Haichao Fu, Yinhui Wang, Xinyan Li, Shi-Jin Shuai
Abstract An experimental study of particulate matter (PM) emission was conducted on four cars from Chinese market. Three cars were powered by gasoline direct injection (GDI) engines and one car was powered by a port fuel injection (PFI) engine. Particulate mass, number and size distribution were measured based on a chassis dynamometer over new European driving cycle (NEDC). The particulate emission behaviors during cold start and hot start NEDCs were compared to understand how the running conditions influence particulate emission. Three kinds of gasoline with RON 91.9, 94.0 and 97.4 were tested to find the impact of RON on particulate emission. Because of time and facilities constraints, only one cold/hot start NEDC was conducted for every vehicle fueled with every fuel. The test results showed that more particles were emitted during cold start condition (first 200s in NEDC). Compared with cold start NEDC, the particulate mass and number of hot start NEDC decreased by a wide margin. The particulate mass and number reductions of hot start NEDC mainly resulted from ECE cycle sections.
Technical Paper
2014-10-13
Barouch Giechaskiel, Urbano Manfredi, Giorgio Martini
Abstract In the current diesel vehicle exhaust emissions legislation Particle Number (PN) limits for solid particles >23 nm are prescribed. The legislation was extended to include Gasoline Direct Injection (G-DI) vehicles since September 2014. Target of this paper was to investigate whether smaller than 23 nm solid particles are emitted from engines in considerable concentration focusing on G-DI engines. The literature survey and the experimental investigation of >15 vehicles showed that engines emit solid sub-23 nm particles. The average percentage over a test cycle for G-DIs (30-40%) is similar to diesel engines. These percentages are relatively low considering the emission limit levels (6×1011 p/km) and the repeatability (10-20%) of the particle number method. These percentages are slightly higher compared to the percentages expected theoretically not to be counted due to the 23 nm cut-off size (5-15%). Higher fraction can be measured with high ethanol content fuels, at sub-zero ambient temperatures and when additives are added in the fuel or lubricant.
Technical Paper
2014-10-13
Piotr Bielaczyc, Andrzej Szczotka, Joseph Woodburn
Abstract Ethanol has a long history as an automotive fuel and is currently used in various blends and formats as a fuel for spark ignition engines in many areas of the world. The addition of ethanol to petrol has been shown to reduce certain types of emissions, but increase others. This paper presents the results of a detailed experimental program carried out under standard laboratory conditions to determine the influence of different quantities of petrol-ethanol blends (E5, E10, E25, E50 and E85) on the emission of regulated and unregulated gaseous pollutants and particulate matter. The ethanol-petrol blends were laboratory tested in two European passenger cars on a chassis dynamometer over the New European Driving Cycle, using a constant volume sampler and analyzers for quantification of both regulated and unregulated emissions. The emissions results revealed non-linear or insignificant changes in response to the addition of ethanol to the base fuel regarding certain parameters; and linear responses regarding others.
Technical Paper
2014-10-13
Kristin Götz, Anja Singer, Olaf Schröder, Christoph Pabst, Axel Munack, Jürgen Bünger, Jürgen Krahl
Abstract One political and economic aim in Europe is to increase the use of renewable energy resources. In the transport sector, up to 10 % of fossil diesel fuel should be replaced by biogenic fuels by 2020. This also means a reduction in crude oil dependency. In the area of diesel fuel, fatty acid methyl esters are introduced since over 20 years as biodiesel. However, biodiesel can lead to an increase of engine oil dilution in passenger cars with diesel particulate filters. During the regeneration of the particulate filters, there is an entry of fuel components in the engine oil. While most of the diesel fuel (DF) evaporates from the engine oil, biodiesel remains in the oil and can cause sludge formation in the engine. A promising approach to reduce this problem is the use of a new type of biogenic fuel, called hydrotreated vegetable oil (HVO). This is also produced from vegetable oil or animal fat. Like biodiesel, HVO is free of sulfur and any aromatics. HVO has a higher cetane number in comparison with biodiesel and most diesel fuels.
Technical Paper
2014-10-13
Jonathan Stewart, Andrew Woods, Roy Douglas, Richard O’Shaughnessy
Abstract With emission legislation becoming ever more stringent, automotive companies are forced to invest heavily in solutions to meet the targets set. To date, the most effective way of treating emissions is through the use of catalytic converters. The catalytic converter will deactivate over its lifetime due to a number of different factors, such as, thermal deactivation, poisoning, fouling and structural breakdown of the catalyst. It is therefore of the utmost importance for automotive companies to test the performance of the catalytic converters under these conditions. Traditionally, catalyst performance testing has been conducted via, vehicle/bench testing, or static thermal aging, with characterization conducted on a laboratory reactor. The disadvantage of vehicle aging is the substantial costs associated with engine testing such as setup and running costs. Static thermal aging using cored samples is more cost effective however not representative of a dynamic testing. This study introduces a methodology in which a full catalyst system with a number of canned catalyst bricks is characterized through a range of performance testing and aging procedures using the Catagen Maxcat at a much reduced cost.
Technical Paper
2014-10-13
Amar Deep, Naveen Kumar, Ashish Karnwal, Dhruv Gupta, Vipul Vibhanshu, Abhishek Sharma, Jitesh Singh Patel
Abstract The interest of using alternative fuels in diesel engines has been accelerated exponentially due to a foreseen scarcity in world petroleum reserves, increase in the prices of the conventional fossil fuels and restrictions on exhaust emissions such as greenhouse gases from internal combustion (IC) engines initiated by environmental concerns. The constant trade-off between efficiency and emissions should be in proper balance with the conventional fuels in a fuel design process for future combustors. Unlike gasoline and diesel, alcohols act as oxygenated fuels. Adding alcohols to petroleum products allows the fuel to combust properly due to the presence of oxygen, which enhances premixed combustion phase, improves the diffusive combustion phase which increases the combustion efficiency and reduces air pollution. The higher activation energy of alcohols leads to better resistance to engine knocking that allows higher compression ratios and greater engine thermal efficiencies. The use of higher alcohols blended with diesel fuel may provide additional advantages compared to short-chain alcohols, i.e. longer molecular un-branched structure of alcohols that means higher calorific value and better cetane number.
Technical Paper
2014-10-13
Xiangang Wang, Zhangsong Zhan, Tiegang Hu, Zuohua Huang
Abstract Performance and particulate emissions of a modern common-rail and turbocharged diesel engine fueled with diesel and biodiesel fuels were comparatively studied. An electrical low-pressure impactor (ELPI) was employed to measure particle size distribution and number concentration. Two biodiesel fuels, BDFs (biodiesel from soybean oil) and BDFc (biodiesel from used cooking oil), as well as ultra-low sulfur diesel were used. The study shows that biodiesels give higher thermal efficiency than diesel. Biodiesels give obviously lower exhaust gas temperature than diesel under high engine speed. The differences in fuel consumption, thermal efficiency and exhaust gas temperature between BDFs and BDFc are negligible. The first peaks of heat release rate for biodiesels are lower than that of diesel, while the second peaks are higher and advanced for biodiesels. BDFs show slightly slower heat release than BDFc during the first heat release stage at low engine speed. BDFs and BDFc show similar heat release rate in the first heat release stage at high engine speed.
Technical Paper
2014-10-13
Jinyoung Jang, Young-Jae Lee, Ohseok Kwon, Minseob Lee, Jeonghwan Kim
Abstract This study focused on the effect of engine oils on regulated emissions, particulates and fuel economy. Three engine oils of the same SAE grade (synthetic oil with poly alpha olefins (PAOs), Group III base oil, and Group III genuine oil with additive package) were used in one gasoline and one diesel vehicle. A GDI (Gasoline Direct Injection) vehicle and a diesel vehicle without DPF (Diesel Particulate Filter) were selected because those vehicles obviously emit more particulates than port-injection gasoline vehicles and diesel vehicles with DPF. A combined mode consisting of the US EPA emission test cycles FTP-75 and HWFET was used for these tests. HORIBA and PIERBURG gas analyzers were used to measure regulated emissions and fuel economy, respectively. Unregulated emissions and particulates were analyzed by FTIR and PPM-S, respectively. Samples (300 ml) of test engine oil were taken periodically just after each test, and the colors of the sampled oil compared. The color of the engine oil samples became dark due to contamination.
Technical Paper
2014-10-13
Christophe Barro, Philipp Meyer, Konstantinos Boulouchos
Abstract Past research has shown that post injections have the potential to reduce Diesel engine exhaust PM concentration without any significant influence in the NOx emissions. In earlier research it was observed that soot reduction due to a post injection is based on three reasons: increased turbulence (1) and heat (2) from the post injection during soot oxidation and lower soot formation due to smaller main injection for similar load conditions (3). The second effect of heat addition during the soot oxidation is debated in the literature. The experimental investigation presented in the current work provides insight into the underlying mechanisms of soot formation and reduction using post injections under different operating conditions. The experimental data have been obtained using a cylindrical constant volume chamber with high optical access. The soot evolution has been obtained using 2-color-pyrometry. Furthermore, NO and particle mass and size distribution have been captured from the exhaust.
Technical Paper
2014-10-13
Matthew McAllister, Stephen Smith, Paul Kapus, Khai Vidmar, Alexander Hochnetz
This paper describes the findings of a design, simulation and test study into how to reduce particulate number (Pn) emissions in order to meet EU6c legislative limits. The objective of the study was to evaluate the Pn potential of a modern 6-cylinder engine with respect to hardware and calibration when fitted to a full size SUV. Having understood this capability, to redesign the combustion system and optimise the calibration in order to meet an engineering target value of 3×1011 Pn #/km using the NEDC drive cycle. The design and simulation tasks were conducted by JLR with support from AVL. The calibration and all of the vehicle testing was conducted by AVL, in Graz. Extensive design and CFD work was conducted to refine the inlet port, piston crown and injector spray pattern in order to reduce surface wetting and improve air to fuel mixing homogeneity. The design and CFD steps are detailed along with the results compared to target. The redesigned high tumble combustion system enabled the engine to meet challenging combustion stability targets at low Pn-levels.
Technical Paper
2014-10-13
Nobunori Okui, Tetsuya Niikuni
Abstract Next-generation vehicles which include Electric Vehicles (EV) and Hybrid Electric Vehicles (HEV) are researched and expected to reduce carbon dioxide (CO2) emissions in the future. In the national new-car sales in 2012 of Japan, the total sales of hybrid vehicles kept 26.5% share. In the field of passenger cars, this share was 29.7%. And, this share rose about four times compared to that of 2008 [1]. Also, small delivery hybrid trucks are increased in the commercial vehicle class. Fuel economy of hybrid trucks in the catalog specifications is relatively better than that of the diesel tracks which have no hybrid systems. Nevertheless, hybrid trucks' users report that advantages of fuel economy of hybrid trucks at the real traffic driving conditions are small. In this report, in order to research that the actual traveling fuel economy of hybrid truck' users has no advantage compared with the diesel truck' users, the traveling fuel economy of hybrid trucks and diesel trucks was surveyed by using the chassis dynamometer system.
Technical Paper
2014-10-13
Z. Gerald Liu, Dana McGuffin, Chris M. Cremeens, Nathan Ottinger, Niklas Schmidt
Abstract More stringent emission requirements for nonroad diesel engines both in the U.S. and Europe have spurred the development of engines and exhaust aftertreatment technologies. In this study, one such system consisting of a diesel oxidation catalyst, zeolite-based selective catalytic reduction catalyst, and an ammonia oxidation catalyst was evaluated using both nonroad transient and steady-state cycles in order to understand the emission characteristics of this configuration. Criteria pollutants were analyzed and particular attention was given to organic compound and NO2 emissions since both of these could be significantly affected by the absence of a diesel particulate filter that typically helps reduce semi-volatile and particle-phase organics and consumes NO2 via passive soot oxidation. Results are then presented on a detailed speciation of organic emissions including alkanes, cycloalkanes, aromatics, polycyclic aromatic hydrocarbons and their derivatives, and hopanes and steranes.
Technical Paper
2014-09-30
Michael Franke, Shirish Bhide, Jack Liang, Michael Neitz, Thomas Hamm
Abstract Exhaust emission reduction and improvements in energy consumption will continuously determine future developments of on-road and off-road engines. Fuel flexibility by substituting Diesel with Natural Gas is becoming increasingly important. To meet these future requirements engines will get more complex. Additional and more advanced accessory systems for waste heat recovery (WHR), gaseous fuel supply, exhaust after-treatment and controls will be added to the base engine. This additional complexity will increase package size, weight and cost of the complete powertrain. Another critical element in future engine development is the optimization of the base engine. Fundamental questions are how much the base engine can contribute to meet the future exhaust emission standards, including CO2 and how much of the incremental size, weight and cost of the additional accessories can be compensated by optimizing the base engine. This paper describes options and potentials to improve the base engine for future commercial and industrial engines.
Technical Paper
2014-09-30
Harry Dwyer, Seungju Yoon, David Quiros, Mark Burnitzki, Roelof Riemersma, Donald Chernich, John Collins, Jorn Herner
Abstract A novel ambient dilution tunnel has been designed, tested and employed to measure the emissions from active parked regenerations of Diesel Particulate Filters (DPFs) for 2007 and 2010 certified heavy duty diesel trucks (HDDTs). The 2007 certified engine had greater regulated emissions than the 2010 certified engine. For a fully loaded 2007 DPF there was an initial period of very large mass emissions, which was then followed by very large number of small particle emissions. The Particle Size Distribution, PSD, was distributed over a large range from 10 nm to 10 μm. The parked regenerations of the 2010 DPF had a much lower initial emission pattern, but the second phase of large numbers of small particles was very similar to the 2007 DPF. The emission results during regeneration have been compared to total emissions from recent engine dynamometer testing of 2007 and 2010 DPFs, and they are much larger. Due to the very wide spectrum in the PSD a wide variety of instrumentation was used, which included the following: (1) Engine On-board diagnostics; (2) Exhaust flow PEMS; (3) Tunnel temperature, CO2, mixture dilution ratio, and relative humidity; (4) Real-time PM instrumentation: EEPS, SMPS, DustTrak, and Dekati Mass Monitor; and (5) Gravimetric filter media.
Technical Paper
2014-09-30
Meng-Huang Lu, Figen Lacin, Daniel McAninch, Frank Yang
Abstract Diesel exhaust aftertreatment solutions using injection, such as urea-based SCR and lean NOx trap systems, effectively reduce the emission NOx level in various light vehicles, commercial vehicles, and industrial applications. The performance of the injector plays an important role in successfully utilizing this type of technology, and the CFD tool provides not only a time and cost-saving, but also a reliable solution for extensively design iterations for optimizing the injector internal nozzle flow design. Inspired by this fact, a virtual test methodology on injector dosing rate utilizing CFD was proposed for the design process of injector internal nozzle flows. For a low-pressure (less than 6 bar) injector application, the characteristic Reynolds number based on the diameter and mass flow rate of the inlet, return flow outlet, and nozzle exit of the injector might range from 2000 to 20000, therefore, employing a flow-physics based viscous model for building up a virtual test methodology is critical to properly capture the fluid dynamics of injector internal nozzle flow.
Technical Paper
2014-09-30
Zhiguo Zhao, Guanyu Zheng, Fengshuang Wang, Suying Zhang, Jianhua Zhang
In order to satisfy China IV emissions regulations, a unique design concept was proposed with injector closely coupled with Selective Catalytic Reduction (SCR) system outer body. The benefit of this design is significant in cost reduction and installation convenience. One paper was published to describe the vertical inlet layout [1]; this work is the second part describing applications of this concept to horizontal inlet configurations. For horizontal inlet pipe, two mixing pipe designs were proposed to avoid urea deposit and meet EU IV emission regulations. Computational Fluid Dynamics (CFD) technique was used to evaluate two design concepts; experiments were performed to validate both designs. CFD computations and experiments give the same direction on ranking of the two decomposition tubes. With the straight decomposition pipe design and unique perforated baffle design, no urea deposits were found; in addition, the emission level satisfied EU IV regulations. Modeling of acoustic insertion loss with GT-Power was implemented and correlated with the tests, the resulting system insertion loss is higher than 20 dB under the rated engine load condition, meeting the acoustic performance targets.
Technical Paper
2014-09-30
Alexander Sappok, Leslie Bromberg
Abstract Diesel Particulate Filters (DPF) are a key component in many on- and off-road aftertreatment systems to meet increasingly stringent particle emissions limits. Efficient thermal management and regeneration control is critical for reliable and cost-effective operation of the combined engine and aftertreatment system. Conventional DPF control systems predominantly rely on a combination of filter pressure drop measurements and predictive models to indirectly estimate the soot loading state of the filter. Over time, the build-up of incombustible ash, primarily derived from metal-containing lubricant additives, accumulates in the filter to levels far exceeding the DPF's soot storage limit. The combined effects of soot and ash build-up dynamically impact the filter's pressure drop response, service life, and fuel consumption, and must be accurately accounted for in order to optimize engine and aftertreatment system performance. This work applied a radio frequency (RF) sensor to directly monitor diesel particulate filter soot and ash levels, thereby enabling direct feedback control of the filter based on its actual loading state.
Technical Paper
2014-09-30
Britney J. McCoy, Arman Tanman
Abstract In-use testing of diesel emission control technologies is an integral component of EPA's verification program. Device manufacturers are required to complete in-use testing once 500 units have been sold. Additionally, EPA conducts test programs on randomly selected retrofit devices from installations completed with grants by the National Clean Diesel Campaign. In this test program, EPA identified and recovered a variety of retrofit devices, including diesel particulate filters (DPFs) and diesel oxidation catalysts (DOCs), installed on heavy-duty diesel vehicles (on-highway and nonroad). All of the devices were tested at Southwest Research Institute in San Antonio, Texas. This study's goal was to evaluate the durability, defined here as emissions performance as a function of time, of retrofit technologies aged in real-world applications. A variety of operating and emissions criteria were measured to characterize the overall performance of the retrofit devices on an engine dynamometer.
Technical Paper
2014-09-30
Manoj K. Sampath, Figen Lacin
Abstract The Diesel engine combustion process results in harmful exhaust emissions, mainly composed of Particulate Matter (PM), Hydro Carbon (HC), Carbon monoxide (CO) and Nitrogen Oxides (NOx). Several technologies have been developed in the past decades to control these diesel emissions. One of the promising and well matured technology of reducing NOx is to implement Selective Catalytic Reduction (SCR) using ammonia (NH3) as the reducing agent. For an effective SCR system, the aqueous urea solutions should be fully decomposed into ammonia and it should be well distributed across the SCR. In the catalyst, all the ammonia is utilized for NOx reduction process. In the design stage, it is more viable to implement Computational Fluid Dynamics (CFD) for design iterations to determine an optimized SCR system based on SCR flow distribution. And in later stage, experimental test is required to predict the after-treatment system performance based on NOx reduction. The SCR model predicts the NH3 formation from urea decomposition and it is quantified at the SCR inlet, whereas experimental data involves the NOx reduction process.
Technical Paper
2014-09-30
Xinyu Ge, Yongli Qi, Kai Zhang
Fuel properties impact the engine-out emission directly. For some geographic regions where diesel engines can meet emission regulations without aftertreatment, the change of fuel properties will lead to final tailpipe emission variation. Aftertreatment systems such as Diesel Particulate Filter (DPF) and Selective Catalytic Reduction (SCR) are required for diesel engines to meet stringent regulations. These regulations include off-road Tier 4 Final emission regulations in the USA or the corresponding Stage IV emission regulations in Europe. As an engine with an aftertreatment system, the change of fuel properties will also affect the system conversion efficiency and regeneration cycle. Previous research works focus on prediction of engine-out emission, and many are based on chemical reactions. Due to the complex mixing, pyrolysis and reaction process in heterogeneous combustion, it is not cost-effective to find a general model to predict emission shifting due to fuel variation. Some empirical models use testing data as input to locate relationships between controlled inputs and engine response.
Technical Paper
2014-09-30
Xiangang Wang, Zhangsong ZHAN, Tiegang Hu, Zuohua Huang
Abstract Experiments were conducted in a turbocharged, high-pressure common rail diesel engine to investigate particulate emissions from the engine fueled with biodiesel and diesel blends. An electrical low-pressure impactor (ELPI) was employed to measure the particle size distribution and number concentration. Heated dilution was used to suppress nuclei mode particles and focus on accumulation mode particles. The experiment was carried out at five engine loads and two engine speeds. Biodiesel fractions of 10%, 20%, 40%, 60% and 80% in volume were tested. The study shows that most of the particles are distributed with their diameters between 0.02 and 0.2 μm, and the number concentration becomes quite small for the particles with the diameters larger than 0.2 μm. With the increase of biodiesel fraction, engine speed and/or engine load, particle number concentration decreases significantly, while the particle size distribution varies little. The analysis on heat release rate, excess air ratio and exhaust gas temperature were provided to help interpret the particulate emissions.
Technical Paper
2014-09-30
Ilya A. Kulikov, Elena E. Baulina, Andrey I. Filonov
Abstract The paper gives a short description of the University's developments in the field of hybrid electric powertrains and vehicles as well as a survey of theoretical instruments utilized in these works for elaboration of powertrains control strategies. At the present, two units fitted with hybrid powertrains are in operation. These are the four-wheel-drive SUV and the powertrain test rig. Both allow to test different powertrain configurations. Prior to implementing a certain configuration in the rig, a theoretical research of powertrain is conducted to reveal its properties and find a way to control it optimally. The basic tool adopted for that purpose is R.Bellman's dynamic programming (DP). The paper gives an example of applying DP to explore a potential of decreasing fuel consumption and pollutant emissions of a light commercial vehicle by converting its powertrain into hybrid one. During this study, a contradiction has emerged between minimizing fuel consumption and emissions of NOx.
Technical Paper
2014-09-30
Philipp Scherer, Marcus Geimer
Abstract As a result of the Kyoto Protocol [1], the European Union's legislation demands higher saving rates for the total energy consumption of technical equipment. Heavy Equipment, such as construction- and agricultural machines, contributes over 80% of the total off-road diesel fuel consumption in Germany per annum. It is therefore necessary to provide helpful solutions in order to reach this ambitious aim. The German Federal Ministry of Education and Research cooperates with machine manufacturers, component suppliers and research institutes in the area of heavy equipment. Under the project name TEAM [2] a three year project has been started, which is focused on the development and integration of new propulsion and steering systems for heavy equipment. One task within the project is finding an appropriate way of evaluating the energy efficiency of the enhanced machines, after the powertrain modifications have been applied to it. The wide range of applicability, as well as the existence of one or more work functions, require a special approach for evaluating the energy efficiency of this category of vehicles.
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