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Automobile Exhaust Emmision Control- A review

Manav Rachna International University-Sunny Bhatia
  • Technical Paper
  • 2019-28-2382
To be published on 2019-11-21 by SAE International in United States
Since the 20th century increase in the number of cars in the major cities is been a point of concern because of the toxic gasses being emitted from the engine of an automobile. These gasses are polluting the atmosphere and degrading the air to breathe. The main gasses responsible for the degradation of air quality are carbon monoxide, hydrocarbon and oxides of nitrogen. There is a necessity to find ways to reduce the pollution emitted into the atmosphere from the automobile. The source of emission is either evaporation from fuel tank or carburetor which is easy to be dealt with or harmful gasses due to improper combustion which is a concern for the environment. The two ways to reduce these emissions are, modification in the engine to minimize the production of harmful gases and to treat the harmful gasses emitted from the engine before blowing it into the atmosphere from the exhaust. Catalysts help to break harmful gasses into smaller compounds that are environment-friendly. The catalysts used are Rhodium Palladium and platinum, these make a…
 

Development of Three Way Catalyst (TWC) ageing model: application of real driving emission condidion

Toyota Motor Europe NV/SA-Julie Le Louvetel-Poilly, Shankar balaji, Francois Lafossas
  • Technical Paper
  • 2019-24-0047
To be published on 2019-09-09 by SAE International in United States
Further reduction of vehicles pollutant and CO2 emissions is required to prevent global warming and to improve air quality. The exhaust system is designed to ensure low emission during all life of the vehicle. As catalyst ageing is affecting the catalyst performance, such impact needs to be consider upfront during the design of the fresh catalyst. Until now, exhaust system design are evaluated based on real tests for each vehicle, using exhaust lines aged on engine test benches or burner benches. This induces major investigation limitations such as: late evaluation in development cycle, high testing and prototyping cost. Usage of Model Based Development approach can be a powerful way to improve this process by allowing system evaluation under several ageing conditions at early development stage. The present study focuses on modelling of Three Way Catalyst (TWC) ageing to predict the mileage impact on tailpipe emissions. The activity was divided in 4 steps: 1- Development of a detailed TWC for 4 different ageing levels. The impact of ageing is considered by tuning Pre-exponential factors of the…
 

Analysis of TWC Operation Characteristics in a Euro6 Gasoline Light Duty Vehicle

Aristotle University Thessaloniki-Grigorios Koltsakis
Empa-Viola Papetti, Panayotis Dimopoulos Eggenschwiler
  • Technical Paper
  • 2019-24-0162
To be published on 2019-09-09 by SAE International in United States
A Euro6 gasoline light duty vehicle has been tested at the engine dynamometer and the emissions have been analyzed upstream and downstream the Three-Way-Catalyst (TWC) during the WLTP cycle. Catalyst simulations have been used for assessing the processes inside the catalytic converter using a reaction scheme based on 19 brutto reactions (Direct oxidation and reduction, selective catalytic re-ductions with CO, C3H6 and H2, steam reforming, water-gas shift and bulk Ceria as well as surface Ce-ria reactions). The reactions have been parametrized in order to best approximate the measurements. Based on the reactions taken into account, the real vehicle emissions can be predicted with good accu-racy. The simulations show that the cycle emissions are comprising mainly by the cold start contribution as well as discrete emission break-through events during transients. During cold start no reactions are evident in the catalyst before the temperature of the gas entering the catalyst reaches 270°C. Following the light-off, prevailing reactions are direct oxidation for CO and direct oxidation as well as surface ceria reactions for THC. NO reduction during cold…
 

One-Dimensional Modeling of a Thermochemical Recuperation Scheme for Improving Spark-Ignition Range Extender Engine Efficiency

Univ of Minnesota-Twin Cities-Darrick Zarling
Univ. of Minnesota-Twin Cities-William F. Northrop
  • Technical Paper
  • 2019-24-0066
To be published on 2019-09-09 by SAE International in United States
Vehicle electrification has accelerated as global fuel efficiency standards have become more stringent and battery costs have decreased. Although full electrification, i.e.; battery electric vehicles, may be appropriate for some light-duty vehicle applications, many vehicles will still require an engine to overcome range limitations. Range extender (REx) engine generators can be used to charge vehicle batteries as needed to meet driver demands. One advantage of REx engines is that they do not have a direct mechanical connection to the wheels and can frequently within the most efficient speed and load ranges. Therefore, REx engines provide an opportunity to implement advanced engine technologies that are more difficult to apply in conventional engine-powered vehicles. Thermochemical recuperation (TCR) schemes use exhaust waste heat to catalytically convert a portion of the fuel into a gas that has increased heating value. TCR schemes are ideal for REx architectures because they yield the most benefit at relatively high engine load and because they do not respond well to rapid transients. This paper explores a TCR scheme for a 2-cylinder BMW spark-ignition…
 

Development of a dedicated CNG three-way catalyst model in 1-D simulation platforms

FPT Industrial SpA-Stefano Golini, Francesco Giovanni Rutigliano
Istituto Motori CNR-Carlo Beatrice, Valentina Fraioli
  • Technical Paper
  • 2019-24-0074
To be published on 2019-09-09 by SAE International in United States
A growing interest in heavy-duty engines powered with CNG dictated by stringent regulations in terms of emissions, has made it essential to study a specific Three-Way Catalyst (TWC). Oxygen storage phenomena characterize catalytic converter efficiency under real world driving operating conditions and, consequently, during strong dynamics in Air-to-Fuel (A/F) ratio. A numerical “quasi-steady” model has been set-up to simulate the chemical process inside the reactor. A dedicated experimental campaign has been performed in order to evaluate the catalyst response to a defined lambda variation pattern of the engine exhaust stream, thus providing the data necessary for the numerical model validation. In fact, goal of the present research activity was to investigate the effect of very fast composition transitions of the engine exhaust typical of the mentioned driving conditions (including fuel cutoffs etc.) on the catalyst performance and on related emissions at the tailpipe. A surface reactions kinetic mechanism, concerning CH4, CO, H2 oxidation and NO reduction, has been appropriately calibrated with a step-by-step procedure in steady-state in the engine work plan at different A/F ratios…
 

Exhaust Purification Performance Enhancement by Early Activation of Three Way Catalysts for Gasoline Engines Used in Hybrid Electric Vehicles

NE Chemcat Corporation-Makoto Nagata
Waseda Univesity-Toshinori Okajima, Ryota Sone, Xieyang Yan, Ryoya Inoue, Suchitra Sivakumar, Hajime Shingyouchi, Jin Kusaka, Kyohei Yamaguchi
  • Technical Paper
  • 2019-24-0148
To be published on 2019-09-09 by SAE International in United States
Three-way catalyst (TWC) converters are used to purify the toxic substances such as carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons (HC) emitted from gasoline engines. However, a large amount of emissions could be emitted before the TWC reaching its light-off temperature during cold start. For hybrid electric vehicles (HEVs) powered by gasoline engines, the emission purification performance by TWC unfortunately become worse caused by mode switching from engine to battery and vice versa, which is possible to generate cold start conditions over and over for TWC In this study, targeting at reducing the emissions from series HEVs by early activation of TWC, numerical simulations with experiments are carried out. A HEV is tested on a chassis dynamometer under Worldwide Light-duty Test Cycle (WLTC) mode; the upstream and downstream gas conditions of the close-coupled catalyst converter are measured. A test piece is taken from the same catalyst and used in model gas experiments for deciding chemical reaction scheme and each corresponding reaction rate parameter. A 1-D numerical simulation TWC model, which includes 13 chemical species…
 

Hybrid Powertrain Calibration Techniques

AVL LIST GmbH-Ernst Winklhofer, Alois Hirsch, Harald Philipp, Michael Trifterer, Manuel Berglez
  • Technical Paper
  • 2019-24-0196
To be published on 2019-09-09 by SAE International in United States
Meeting the particle (PN) emissions limits in dynamic vehicle test sequences needs specific attention on each power variation event occurring in the internal combustion engine (ICE). Such transients arise from engine start onwards along the entire test drive. In hybrid systems, there is one further source for transient ICE response: each power shift between E-motor (EM) and ICE introduces gas flow variations with subsequent temperature response in the ICE and in the engine aftertreatment system (EAS). This bears consequences for engine out emissions as well as for the EAS efficiency and even for the durability of a catalytic converter. As system calibration engineers must decide on numerous actuator parameters, their decisions, finally, are crucial for meeting legislative limits under the boundary conditions given by the ICE’s hybrid and drive environment. The paper reports on a methodology to measure - on a degree crank angle basis - and evaluate the ICE and EAS response to the vehicle drive requirements and the power shift dynamics between EM and ICE. Focus, in particular, is given to 1. particle…
 
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Event-Driven Simulation of Particle-Particle and Particle-Surface Collisions in Ice Crystal Icing

ICI Physics-Thomas Charles Currie
Published 2019-06-10 by SAE International in United States
This paper describes an event-driven simulation tool for predicting particle-particle and particle-surface interactions in ice crystal icing (ICI). A new accretion model which is much less empirical than existing models for predicting ICI accretion is also described. Unlike previous models, the new “gouge/bounce model” (GBM) differentiates between (erosion) losses resulting from particle bounce and those resulting from particle gouging. A bounce threshold based on the tangential Stokes number is used to calculate most of the bounce loss. The GBM also predicts ejecta velocities and directions, at least approximately, which is important because most of the mixed-phase mass flux impacting a surface actually bounces off or erodes existing material in ICI, thereby increasing the mass flux downstream. The event-driven simulation tool, denoted COLLIDE, has been applied to two test cases in which accretion growth appeared to be affected by TWC in a manner beyond that which would be expected from the accumulation parameters. An existing correlation-based accretion model (CBM), modified to predict erosion dependence on particle diameter, is also implemented and applied to the test cases.…
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Analysis and Automated Detection of Ice Crystal Icing Conditions Using Geostationary Satellite Datasets and In Situ Ice Water Content Measurements

Met Analytics, Inc.-J. Walter Strapp
NASA John Glenn Research Center-Thomas Ratvasky
Published 2019-06-10 by SAE International in United States
Recent studies have found that high mass concentrations of ice particles in regions of deep convective storms can adversely impact aircraft engine and air probe (e.g. pitot tube and air temperature) performance. Radar reflectivity in these regions suggests that they are safe for aircraft penetration, yet high ice water content (HIWC) is still encountered. The aviation weather community seeks additional remote sensing methods for delineating where ice particle (or crystal) icing conditions are likely to occur, including products derived from geostationary (GEO) satellite imagery that is now available in near-real time at increasingly high spatio-temporal detail from the global GEO satellite constellation. A recent study using a large sample of co-located GEO satellite and in-situ isokinetic evaporator probe (IKP-2) total water content (TWC) datasets found that optically thick clouds with tops near to or above the tropopause in close proximity (≤ 40 km) to convective updrafts were most likely to contain high TWC (TWC ≥ 1 g m-3). These parameters are detected using automated algorithms and combined to generate a HIWC probability (PHIWC) product at…
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Evaluation of Emissions from Light Duty Trucks with and without the Use of a Gasoline Particulate Filter

Environment and Climate Change Canada-Fadi Araji, Jonathan Stokes
Published 2019-04-02 by SAE International in United States
The goal of this study was to investigate the emission impacts of replacing the OEM three-way catalyst on light duty trucks using various, commercially available, gasoline particulate filter (GPF) configurations. Three light duty trucks were tested: a Port Fuel Injection (PFI) PFI_1 and two Gasoline Direct Injection (GDI) vehicles GDI_1 and GDI_2. The testing of these vehicles was conducted on a chassis dynamometer in a controlled test cell environment at two temperatures (25 °C and -7 °C) using the Federal Test Procedure (FTP-75) and the US06 test procedure. All three vehicles were tested in stock OEM configuration followed by testing PFI_1 and GDI_1 with a non-catalyzed GPF and GDI_2 with a catalyzed GPF. GDI_2 was also tested on-road using a portable emissions measurement system (PEMS) with and without the use of the catalyzed GPF. Gaseous emissions, Particulate Matter (PM), Black Carbon (BC) and Particle Number (PN) emissions were measured. Results for the non-catalyzed GPF configuration on PFI_1 and GDI_1 showed a decrease in PM at both standard and cold temperatures, with the biggest decrease being…
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