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A Methodology for Monitoring Real-World CO2 Emissions Compliance in Passenger Vehicles

Aristotle University of Thessaloniki-Nikiforos Zacharof, Stylianos Doulgeris, Ioannis Myrsinias, Zisimos Toumasatos, Athanasios Dimaratos, Zissis Samaras
European Commission Joint Research-Georgios Fontaras
  • Technical Paper
  • 2020-37-0034
To be published on 2020-06-23 by SAE International in United States
The road transport CO2 emissions reduction scheme in the European Union foresees mandatory targets for passenger vehicles. However, several studies have shown that there is a divergence between official and real-world values that it could be up to 40% in the NEDC. The introduction of the WLTP was expected to curb this divergence, but it is uncertain whether it can fully address the problem. In order to address this issue, future legislation aims at monitoring on-road fuel consumption and subsequently CO2 emissions by utilizing on-board fuel consumption meters. The current study investigates a monitoring approach that obtains and normalizes on-road vehicle operation data and estimate CO2 emissions through vehicle simulation. The first step is to create the vehicle’s engine fuel consumption map, based on laboratory vehicle measurements in order to use it as reference data. Subsequently, a methodology is developed to produce the vehicle’s engine map from signals retrieved through the OBD port in order to emulate data availability under a monitoring scheme. The methodology to derive the vehicle’s engine fuel consumption map includes an…
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A Novel Option for Direct Waste Heat Recovery From Exhaust Gases of Internal Combustion Engines

Universita degli Studi dell Aquila-Davide Di Battista, Roberto Cipollone PhD, Roberto Carapellucci PhD
  • Technical Paper
  • 2020-37-0004
To be published on 2020-06-23 by SAE International in United States
Among the different opportunities to save fuel and reduce Co2 emissions from internal combustion engines, great attention has been done on the waste heat recovery: the energy wasted is, in fact, almost two thirds of the energy input and even a partial recovery into mechanical energy is really promising . Usually, thermal energy recovery has been referred to a direct heat recovery (furtherly expanding the gases expelled by the engine thanks to their high pressure and temperature) or an indirect one (using the thermal energy of the exhaust gases – or of any other thermal streams discharged into the atmosphere – as upper source of a conversion power unit which favour a thermodynamic cycle of a working fluid ). Limiting the attention to the exhaust gases, a novel opportunity can be represented by directly exploiting the residual pressure and temperature of the flue gases through an Inverted Brayton cycle (IBC), in which the gases are expanded at a pressure below the environmental one, cooled down and then recompressed to the environmental pressure. Considering the thermodynamic…
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Simulation of Driving Cycles by Means of a Co-Simulation Framework for the Prediction of IC Engine Tailpipe Emissions

Exothermia SA-Vasileios Tziolas, Nikolaos Zingopis
Politecnico di Milano-Gianluca Montenegro, Angelo Onorati, Gianluca D'Errico, Tarcisio Cerri, Andrea Marinoni
  • Technical Paper
  • 2020-37-0011
To be published on 2020-06-23 by SAE International in United States
The current European legislation concerning pollutant emissions from IC engine vehicles is very stringent and demanding. In addition, the CO2 fleet emission must obey to a significant reduction path during the next decade, to cope with the prescribed targets recently agreed. The prediction of pollutant emissions from IC engines has been a challenge since the introduction of the emission regulation legislation. During the last decade, along with the more tightening limits and increased public concern about air quality, the capability of simulating different operating conditions and driving cycles with an acceptable computational effort has become a key feature for modern simulation codes. The role of 1D thermo-fluid dynamic simulation models is extremely important to achieve this task, in order to investigate the performances of the next generation of IC engines working over a wide range of operating conditions, under steady-state and transient conditions. This work is based on the idea of integrating two different 1D simulation tools in a co-simulation environment, realizing a strict numerical coupling between the two codes. The main goal is to…
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Effect of Prechamber on Exhaust Emission and Efficiency of a SI Small Engine Fuelled with Gaseous and Liquid Fuels

Istituto Motori CNR-Paolo Sementa
  • Technical Paper
  • 2020-37-0035
To be published on 2020-06-23 by SAE International in United States
The aim of the study was the optimization of the gasoline combustion process by means of a passive/active prechamber. The improvement of the engine efficiency in lean-burn operation condition is an opportunity to give further use of Spark Ignition (SI) engine. A commercial small Spark Ignition (SI) engine was modified with a proper designed prechamber fuelled with methane. Engine performance in terms of indicated Mean effective pressure, heat release rate and fuel Consumption were evaluated as well as gaseous emissions. Particulate Mass, Number and Size Distributions were measured. Several engine operative conditions were investigated at full load varying the engine speeds for stoichiometric and lean conditions and with different prechamber types. The results were compared with those obtained with the engine equipped with the standard spark plug. The results indicated that both performance and emissions were strongly influenced by the prechamber.
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Fuel Consumption and Emission Reduction for Hybrid Electric Vehicles with electrically heated Catalyst

TU Dresden-Frank Atzler
TU Muenchen-Georg Wachtmeister
  • Technical Paper
  • 2020-37-0017
To be published on 2020-06-23 by SAE International in United States
Hybridization is a promising way to further reduce the CO2 emissions of passenger vehicles. However, high engine efficiencies and the reduction of engine load, due to torque assist by an electric motor, cause a decrease of exhaust gas temperature levels. This leads to an increased time to light-off of the catalysts resulting in an overall lower efficiency of the exhaust aftertreatment system. Especially in low load driving conditions, at cold ambient temperatures and on short distance drives, the tailpipe pollutant emissions are severely impacted by these low efficiency levels. To ensure lowest emissions at all driving conditions, catalyst heating methods must be used. In conventional vehicles internal combustion engine measures, e.g. late combustion can be applied. A hybrid system with an electrically heated catalyst enables further methods such as the increase of engine load, the so-called load point shifting by the electric motor or using the energy from the battery for electric catalyst heating. Since these methods result either directly or indirectly in additional fuel consumption there is a conflict of objectives between a fast…
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Impact of Thermal Management of the Three-Way Catalyst on the Energy Efficiency of a P2 Gasoline FHEV

Università del Salento-Marco Benegiamo, Andrea Valletta, Antonio Carlucci
Università di Roma Tor Vergata-Vincenzo Mulone
  • Technical Paper
  • 2020-37-0019
To be published on 2020-06-23 by SAE International in United States
Gasoline Full Hybrid Electric Vehicles (FHEVs) are recognized as a cost-effective solution to comply with upcoming emissions legislation. However, several studies have highlighted that frequent start-and-stops worsen the HC tail-pipe emissions, especially when the light-off temperature of the three-way catalyst (TWC) has not been reached. In fact, strategies only addressing the minimization of fuel consumption tend to delay engine activation and hence TWC warming, especially during urban driving. Goal of the present research is therefore to develop an on-line powertrain management strategy accounting also for TWC temperature, in order to reduce the time needed to reach TWC light-off temperature. A catalyst model is incorporated into the model of the powertrain where torque-split is performed by an adaptive equivalent consumption minimization strategy (A-ECMS). The developed A-ECMS operates on a domain of power-split combinations between electric machine and internal combustion engine, which, aside from satisfying the torque demand, also ensure a controlled ICE torque derivative as well as a controlled ICE start-and-stop frequency. Hence, the algorithm which is extended for TWC thermal management, incorporates a penalty on…
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Simplified Cost-effective Aftertreatment System for Electrified Diesel Applications

Exothermia SA-Dimitrios Karamitros, Christos Avgerinos, Stavros Skarlis, Grigorios Koltsakis
GM Global Propulsion System-Giuseppe Previtero, Fransesco Bechis
  • Technical Paper
  • 2020-37-0023
To be published on 2020-06-23 by SAE International in United States
The Diesel powertrain remains an important CO2 reduction technology in specific market segments due to its inherent thermodynamic combustion efficiency advantages. Diesel powertrain hybridization can bring further potential for CO2 emissions reduction. However, the associated reduction in the exhaust gas temperature may negatively impact the performance of the exhaust aftertreatment (EAT) system and challenge the abatement of other emissions, especially NOx. Considering that active urea-SCR systems may be required to ensure compliance with the legislative limits, the total cost of the hybrid Diesel powertrain is expected to increase even more, therefore making it less commercially attractive. We present a model-based analysis of a 48V Diesel mild hybrid electric vehicle (MHEV) which is combined with an exhaust aftertreatment (EAT) system using Lean-NOx trap (LNT) technology. The overall de-NOx performance is further enhanced with the addition of passive SCR catalysts to benefit from the on-board ammonia formation during rich combustion events. Since the modeling framework is fully physico-chemically informed, it allows the investigation of various topologies, catalyst geometrical and chemical properties. Moreover, the model includes a simplified…
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The Influence of Fuel Composition and Renewable Fuel Components on the Emissions of a GDI Engine

Porsche AG-Hans-Peter Deeg, Dietmar Schwarzenthal
Technical Univ of Braunschweig-Michael Albrecht, Peter Eilts
  • Technical Paper
  • 2020-37-0025
To be published on 2020-06-23 by SAE International in United States
Investigations were performed, in which the emission behavior of renewable and conventional fuels of different composition and renewable fuel components was observed. The influence on the emissions of the start of injection at different load points was investigated. This shows how much wall and valve wetting affects the mixture formation of the different fuels. Further, the air fuel ratio in an operating point for catalyst heating, with medium engine temperatures, was varied. The latter shows the ability of evaporation of the fuels at engine warm-up conditions and sub-stochiometric λ-Values. The studied fuels were four fuel mixtures of significantly different composition of which three were compliant with the European fuel standard EN 228. A RON 98 in-field fuel, a Euro 6 reference fuel, an Anti-Spark-Fouling (ASF) fuel (designed for minimum soot production) and a potentially completely renewable and CO2-neural fuel, which is designed by Dr. Ing. h.c. F. Porsche AG, named POSYN (POrsche SYNthetic fuel) were chosen. Additionally, the fuel components Ethanol as classic biofuel, Isopropanol, Isobutanol and methyl tert-butyl ether (MTBE), which were chosen by…
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Assessment of the Potential of Power to Gas Fuels for Replacement of Fossile Fuels in Switzerland

EMPA-Panayotis Dimopoulos Eggenschwiler, Florian Kiefer, Karin Schröter, Christian Bach
  • Technical Paper
  • 2020-37-0027
To be published on 2020-06-23 by SAE International in United States
In Switzerland, road traffic is responsible for one third of greenhouse gas emissions respectively 40% of the CO2 emissions and therefore accounts for the largest single share of all sectors. These emissions have even increased slightly since 1990 (from 15.5 to 16.2 million tCO2). Private individual road transport achieves a mileage of approximatively 91.0 billion pkm (person-kilometer) and 17.2 billion tkm (tons-kilometer) per year. Therefore, 3.3 billion liters of gasoline and 3.2 billion liters of diesel are used, resulting in 16.2 million tCO2 emissions in total. Thereof, 10.2 million tons of CO2 are emitted by passenger cars and 1.7 million tons by trucks, the two most important means of transport concerning CO2 emissions. The rest is produced by vans, buses, motorcycles, railways and shipping, national air traffic and fuel tourism. The passenger cars are the most relevant application in terms of CO2 emissions with a share of 63% of the road vehicle CO2 emissions. To comply with the 95 g/km target, low CO2 vehicles have to be introduced. In the following, the number of such…
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Energy Management for Electric Vehicle Application: Energy Demand for Cabin Comfort

FCA Italy S.p.A.-Antonio Tarzia
  • Technical Paper
  • 2020-37-0031
To be published on 2020-06-23 by SAE International in United States
The rapid development of CO2 reduction policies pushes an equivalent effort by the OEM to design and produce Battery Electric Vehicles (BEV) in order to lower the global CO2 emission of its fleet. The main effort has been done primarily to the electric traction architecture (electric traction motor and battery energy storage). Anyway, the BEV autonomy range is still a weak point and this is even more critical when the customer operates the air conditioning system to reach and maintain the cabin comfort. The aim of this work is to present how the cabin design have to evolve in order to allow the reduction of the energy demand by the Air conditioning system allowing the vehicle to increase the autonomy range.