Internationaler Motorenkongress 2020

Frontmatter

Results of a patent analysis and a market study to assess future concepts of hybrid vehicles

Zusammenfassung

Due to changing requirements of automotive customers, society and politics, alternatives to the well-known pure internal combustion engine drives are needed as propulsion concepts. One possibility is the hybridization of an en-gine together with at least one electric motor. By different interconnections of these drive units, a wide variety of propulsion topologies can be provided.

To estimate future concepts, developments reflected in patent applications are used. Basis is an overall analysis of patent applications filed with the European Patent Office. By extracting cumulations of filings in individual categories, trends of developments can be derived.

Applicants based in Europe mainly file a wide range of different topologies of parallel hybrid concepts. Primarily, these are based on further development of the known components. In particular, P1-, and, more recently, P2- and P12-hy-brids are frequently found. In contrast, the majority of Applicants based in Asia are focused on power-split hybrids. Toyota, the largest Applicant for patents in the field of hybrid vehicles, is focused on continuously variable transmissions. Other Applicants from Asia are focused on parallel-serial hybrids. In the US, due to a smaller number of applications no profound statements can be made.

For a vehicle with a retail price of approx. € 20,000, a hybrid powertrain concept is presented based on a simplified three-cylinder gasoline engine in order to achieve the ambitious cost target.

Wilhelm Hannibal, Niklas Haverkamp, Peter Eilts

TwinRex – Dedicated Hybrid Engine for a serial-parallel powertrain with excellent cost-value index

Zusammenfassung

Environmental-friendliness is in the focus of customers and has become a dominant driver for powertrain electrification. FEV has developed the TwinRex hybrid system to match lowest CO2-targets and real life fuel efficiency at affordable costs. A simplified transmission enables full electric driving as well as series and parallel hybrid operation modes. The internal combustion engine (ICE) is dedicated to these hybrid modes. ICE-Technology investment focuses on high efficiency in relevant operation zones, while simplifying technology is sufficient for operation zones of lower interest in this highly electrified environment. Two general engine concepts, a turbocharged and a naturally aspirated version are compared in detail. The turbocharged 1.5 l 3-cylinder engine version achieves a peak efficiency of 43 % at stoichiometric combustion. The naturally aspirated engine version achieves 42.5 % efficiency with a bigger cylinder displacement. Due to the higher torque of the turbocharged engine, the electric machines, inverters and the battery can become smaller, making the hybrid powertrain with the turbocharged engine not only more efficient, but also cheaper. Insight is also given on how such a turbocharged 3-cylinder engine can achieve best NVH performance and how the TwinRex system supports achievement of the expected Post-Euro 6 emission legislation.

Matthias Thewes, Adrian Schloßhauer, Oguz Budak, Jörg Seibel, Reiner Wohlberg, Andreas Müller, Johannes Moritz Maiterth, Markus Eisenbarth, Ruben Keizer, Farouk Odeim, Michael Kauth, Rene Savelsberg, Georg Birmes, Andreas Balazs, Tolga Uhlmann, Johannes Scharf, Norbert Alt, Andreas Sehr

Future diesel powertrain in LCV and SUV – electrified, modular platform with focus on emission, efficiency and cost

(Zukünftige Dieselantriebe in LCV und SUV – Elektrifizierte, modulare Plattform mit Fokus auf Emission, Effizienz und Kosten)

Zusammenfassung

Considering worldwide future emission and CO₂-legislation for the Light Commercial Vehicle segment a wide range of powertrain variants has to be expected. Dependent on the application use case all powertrain combinations from Diesel-propulsion only via various hybrids to pure battery electric variants will be introduced.

Under this aspect as well as facing global legislation updates and market reguirements a modular approach is shown for the LCV and SUV Segment in the displacement range of 2.0L to 2.3L, which allows flexible adjustment for different requirements. In regard of commercial boundaries tailored technology pack-ages, engine related technical features towards emission- and fuel consumption improvement, as well as electrification measures, in particular 48V-MHEV variants, are defined and compared, with cost-effectiveness and efficiency as essential criteria.

Wolfgang Schöffmann, Michael Howlett, Bernhard Enzi, Stefan Krapf, Christoph Sams, Hannes Wancura, Michael Weißbäck, Helfried Sorger

MPI valves for use in large engine applications – challenges in the development and derived benefits for operation

Zusammenfassung

Different factors have to be considered during the development of ported fuel injection valves. Customer specifications as well as legal requirements and economical goals pose a challenge during the development process. In this paper the authors presents aspects of an integrated approach for the optimization of ported fuel injection valves for large bore engines in order to meet those requirements with special focus given on current challenges from the market and the achieved benefits for engine operation.

Engine concepts like dual-fuel engines help to combine the advantages of die-sel and pure natural gas engines, but also increase the demands in regards of robustness and durability of the used fuel injection equipment especially in terms of MPI valves. High EGR rates in combination with a dynamic engine operation lead to an increased need of robust valve design.

In order to cope with this market demands and to derive the best possible benefit for the engine operator an integrated approach of component optimization and later validation with component as well as engine tests was chosen to verify the expected benefits of the chosen development approach.

Benefits like long term operation of the developed MPI valves and thereby reduced TCO for the engine operator, minimized valve leakage in combination with high valve dynamics and robust behavior under all kind of operation conditions were achieved. Those benefits are described in the paper and linked to the integrated development process.

Peter Christiner, Claudia Hengstberger, Markus Schmitzberger, Michael Köhler

Direction of gas vehicle development in Japan

Zusammenfassung

Founded in 1916, Isuzu Motors Limited (ISUZU) has the longest history among existing Japanese vehicle manufacturers, with capital of 338,33 million EUR, consolidated 17.91 billion EUR in sales, and 37,263 employees, as of March 2019.

Akiyoshi Kishi

Managing cryogenic fuels on heavy-duty HPDI vehicles

Zusammenfassung

Westport Fuel Systems’ High Pressure Direct Injection (HPDI) technology is commercially available in Europe on OEM Heavy Duty trucks, with further applications expected to be released in China shortly. HPDI allows Heavy Duty trucks to retain the advantages of the diesel engine (torque, transient response, efficiency and durability) while gaining the advantage of a cheaper fuel and maximizing the CO₂ reduction relative to diesel. The latter is particularly important with the latest European legislation, which requires a reduction of 15% by 2025, and 30% by 2030; HPDI equipped engines have already shown a 20% reduction in CO₂, and, coupled with the planned vehicle and engine improvements, is expected to meet the 2030 targets. The potential inclusion of renewable natural gas as a further reduction factor in the legislation could effectively lead to a 100% reduction in the CO₂ emissions of an HPDI vehicle.

While an HPDI engine runs on high pressure compressed gas, the off-engine system typically stores the fuel cryogenically to maximize the vehicle range. Cryogenics present interesting challenges for vehicle applications; hold time is a consideration for any cryogenic system, while customer requirements such as maximizing range, and minimizing weight and space claim add conflicting factors. While these considerations impact any vehicle using a cryogenic system, the high pressure gas requirement for HPDI adds another factor: how to supply compressed gas with minimal parasitic impact to the engine. This paper explores internal and external pumping of gas, and approaches for minimizing vented gas and maximizing hold time. The paper concludes with a look toward future opportunities.

Adrian Post, David Mumford, Robbi McDonald, Gage Garner

Systemic development approach for optimizing piston ring design to reduce particulate raw emissions

Zusammenfassung

Due to growing attention on the effects of air-pollutant emissions on human health and the environment, there is now enormous focus on the influence of energy conversion processes. Different types of emissions are released into the environment during the combustion of fossil fuels and oils. Particulate emissions contribute to a significant extent to total emissions, resulting in negative effects on both the environment and human health [1].

Thomas Bastuck, Richard Mittler, Steffen Hoppe

The ring catalyst – an innovative, ultracompact solution for EU7

Zusammenfassung

“Unrestricted clean mobility” is the goal of the development of modern,future powertrain systems. The focus is on robust exhaust gas aftertreatment in theentire engine map with simultaneous CO2 reduction supported by electrification. Highly effective combustion engines, turbocharged with high efficient catalytic converter technology and the latest engine management control are the basic prerequisites for achieving this goal. The ring-catalytic converter, originally developed for truck and non-road applications, enables the extremely compact construction of a new, innovative exhaust gas aftertreatment system as an integrated unit consisting of turbocharger and catalytic converter.

The modification of the turbocharger housing and the turbine outlet including the wastegate also enables the efficiency of the turbocharger to be increased. At high-load points, a perfect mixing of the wastegate flow with the main exhaust gas mass flow leads to a reduction in the local catalytic converter temperatures, which means that the lambda 1 map can be expanded.

The article describes the development of the ring catalyst and the integration into the turbocharger from the design phase to testing on an engine test bench. In addition to CFD simulations, measurements of efficiencies, pressure loss and flow distributions are shown. Final practical tests on the engine test bench show the potential of the close-coupled ring catalyst also in combination with a HC-Adsorber system.

Rolf Brück, Thomas Härig

Variable valve actuation as an efficient measure for Off-Highway (OHW) drive systems

Zusammenfassung

Modern legislation for internal combustion engines is forcing the truck and the Off-highway engine designers to manage the trade-off between efficiency in terms of TCO and the ecological foot print regarding fuel consumption and exhaust gas emissions. Therefore, modern exhaust gas aftertreatment systems are used to decrease the emissions of PM, NOx and CO but these systems require a certain gas temperature to start the exothermal catalytic reaction in the SCR system and ensure an adequate CRT-effect on the Diesel particle filter. In part load conditions the heat from the exhaust gas is often not sufficient and options to increase the temperatures are required. There are different possibilities of engine modifications that can enable such thermal management effects with differences in temperature increase on one hand and the fuel penalty on the other hand.

In this approach DEUTZ, MAHLE and HILITE investigated the use of a variable exhaust valve train in a DEUTZ 4-cylinder SOHC development engine. The variable valve actuation is realized by a MAHLE CamInCam truck camshaft providing DOHC functionality in a SOHC envelope in combination with a truck specific generic phasing system by HILITE.

This paper shall describe the DEUTZ engine architecture and explain the details of the hardware used as functional description of the CamInCam camshaft and the truck phasing system.

The trials itself and the results from these investigations in a fired engine condition in terms of exhaust gas temperature increase will be presented. Additionally, findings on how to improve in parallel (same hardware) the low-end torque potential of the engine are described. Therefore, the system will contribute to the legislative admissions without sacrificing driveability.

Georg Töpfer, Adrian Troeger, Justus Himstedt, Stefan Steichele

CO2 reduction by minimizing friction at the pcu in conflict of targets with increased oil aerosol formation

Zusammenfassung

The reduction of frictions losses in the drivetrain of modern internal combustion engines is one of the main development paths to lower fuel consumption and thus the CO₂ emission.

The Euro VI emissions legislation introduced a total particle number limit. In addition to particle emissions from the aftertreatment system, an open crankcase ventilation system could be another source.

Modern separator systems are capable to eliminating almost all particle mass emissions from the blow-by gas, but even active separators are not capable of separating small aerosol particles of 1μm and smaller in diameter with high efficiency. Therefore, investigations have been carried out to locate the source of these small oil aerosol particles and to reduce their formation. The main source of these small particles was identified as the drivetrain.

However, this is exactly the area were most measures for friction reduction are applied.

Therefore, this publication focuses on the conflict of targets between reduction of friction losses and the increased oil aerosol formation at the drivetrain of a modern diesel internal combustion engine.

This article points out the blow-by flow effect of tangential tension of a spring-loaded oil control ring and the sealing performance of second piston ring as essential lever for small oil aerosol formation.

In addition, it is shown that with a fine honing structure of the cylinder liner, both objectives are advantageous.

Magnus Lukas Lorenz, Thomas Koch

HD diesel engine – exhaust gas temperature management and advanced exhaust gas aftertreatment technology for ultra-low NOx emission legislation

Zusammenfassung

Upcoming ultra-low NO_x emission legislations in the USA and Europe will require the fulfilment of very low emission limits. Therefore, a highly efficient exhaust aftertreatment system in combination with a suitable control architecture, low NO_x engine out emissions and rapid heat-up measures becomes mandatory. Using a 2-stage SCR system with a close coupled SCR as a first catalyst in the aftertreatment system combined with enhanced thermal management measures allows high NO_x conversion immediately after cold start and in low load operation. The 2^nd SCR also supports NO_x conversion in high load and high temperature operation. Additionally, a smart NO_x conversion balancing over the two SCR stages leads to benefits in terms of passive DPF regeneration associated with high PN filtration efficiency. In the hot FTP cycle, NO_x conversion above 99.5% is obtained confirming the high potential of the engine and EAS concept to achieve ultra-low NO_x emissions.

Jonas Edvardsson, Klaus Hadl, Eric Hein, Georg Kraus, Hannes Noll, Christina Schwarz, Stefanie Tamm, Helmut Theissl

Processes for the production of OME fuels

Zusammenfassung

Poly(oxymethylene) ethers (OME) are synthetic diesel fuels, which show extremely low soot formation during combustions. They are heavily discussed as future climate-friendly alternative to fossil diesel fuels, e.g. via an e-fuel route. To put this discussion on solid grounds, it is important to look at how OME are actually produced. This paper given an overview of the technology for the production of OME. The raw materials and the roles of the intermediates (synthesis gas, methanol, formaldehyde, dimethyl ether, and trioxane) in the valued added chain toward OME are explained. Technically feasible process concepts are described and assessed regarding economics and energetic efficiency. Current and future research directions for finding novel, improved production routes are discussed, before the paper is concluded.

Jakob Burger, Hans Hasse

Fahrplan zu einer OME-Spezifikation (Roadmap to an OME specification)

Zusammenfassung

Oxymethylenether (OME) ist ein synthetischer Dieselkraftstoff. Der Kraftstoff verbrennt rußfrei und hat eine hohe Cetanzahl. OME verfügt somit über vorteilhafte Verbrennungseigenschaften. In dieser Arbeit wird der Aufbau und der aktuelle Stand der OME-Spezifikation vorgestellt. Die Bedeutung der Parameter ‘Cetanzahl’, ‘Flammpunkt’, ‘Gefrierpunkt’ und ‘Oxidationsstabilität’ für OME als Kraftstoff werden erläutert. Diese Parameter lassen sich in der Produktion durch destillative Abtrennung und Recycling der kurzkettigen OME_1-2 und der langkettigen OME-Komponenten OME_5-6 auf einfache Weise einhalten.

Thomas Wilharm, Hendrik Stein, Innokentij Bogatykh

The second generation electrically driven compressor – more power for more possibilities

Zusammenfassung

In 2017, the BorgWarner eBooster^®, an electrically driven compressor, did make its world premiere in series production on a 3 liter – six-cylinder inline gasoline engine [14]. Vehicle customers and legislators worldwide demand better fuel economy in new engines. Electrically powered turbocharging systems, enabled by increasing electrification of vehicles, allow higher specific torque and engine power, thus enabling downsizing and down-speeding without compromising transient behavior.

Hermann Breitbach, Ralf Christmann, H. Gabriel, Dietmar Metz

Design of electrified turbomachinery for use in modern industrial hybrid powertrains

Zusammenfassung

Whilst the automotive industry has made progress with electrified turbomachinery at the passenger vehicle scale, progress has been slower for heavy duty, on and off-highway, and industrial scale engines. But, the numbers of these engines, and their contribution to carbon emissions and general pollution, are still significant.

Through combining high speed electrical machines with turbocharger components to create electrified turbomachinery, it is possible for these users to gain responsiveness, reduce engine start times and reduce emissions. By recovering waste exhaust energy, the electrical power generated can be used to feed hybrid system batteries and motors leading to beneficial reductions in specific fuel consumption, NO_x and CO₂ emissions. This paper will explore the development of two products that leverage this technology, the electric compressor and electric turbocharger.

Shinri Szymko, Owen Creese-Smith, Gael de Crevoisier, Michela Mascherin, Richard Goodyear, Henry Carr

Hydrogen to deal with intermittency of renewable electricity generation

Zusammenfassung

The trend towards renewable energy sources will continue under the pre-amble of GHG emission reduction targets. The available renewable energy is higher than the global energy demand. The question is how to harvest and store it properly. Intermittency of renewable energy resources makes the supply less predictable compared to traditional energy sources like coal or gas. Chemical energy carriers like hydrogen and synthetic fuels seem to be at least part of the solution for storing renewable energy. The efficiency of the well-to-wheel energy chain will be essential. Increasing the efficiency in the electrolysis leverages a high potential. Choosing the right energy storage method is linked to the amount of future energy surplus to be stored. In a possible ramp-up scenario small closed fleets can be the starting point for ramping up to a CO₂ neutral transport sector.

Martin Rothbart, Jürgen Rechberger, David Reichholf, Richard Schauperl

Hydrogen as a fuel – Shell’s view on providing hydrogen for heavy-duty mobility applications

Zusammenfassung

Hydrogen and fuel-cell technologies have significant potential to enable the transition to a clean and low-carbon energy system. Hydrogen is a clean and versatile energy carrier that can be used as a fuel for power, transport, and in industry as feedstock. Viewing hydrogen for heavy duty applications in context of the overall fuels landscape, in particular passenger car applications, this paper analyses the needs for heavy duty infrastructure and the remaining development needs. Questions of energy import, distribution and dispensing to the customer are analysed, particularly the differences in liquid and pipeline transport.

Paul Karzel, Jason Munster, Andreas Kolbeck

50 % brake thermal efficiency – the realization of a vision

Zusammenfassung

GHG and CO₂ legislations in US, Europe and China demand a reduction of emissions in the range of 25 to 30% for heavy commercial vehicles in the current decade. To meet these challenging targets, a further increase of the efficiency of the internal combustion engine is one of various optimization parameters. AVL develops engine concepts to increase the brake thermal efficiency (BTE) to 50%, focusing on base-engine improvements. This requires a spec. fuel consumption below 170 g/kwh. This article shows AVL’s research results, which are based on the testing results of a single cylinder research engine and on 1D-thermodynamic simulations. From these results, challenges for design and friction requirements are derived. Finally, the strengths and weaknesses of diesel engine concepts with the potential for 50% BTE are discussed.

Rolf Heinrich Dreisbach, Martin Wieser, Franz Hofer, Helmut Theissl, Hans Felix Seitz, Kurt Schmidleitner, Heinz-Georg Flesch, Andreas Horvath, Jürgen Gelter, Wolfgang Gruber, Martin Piffl

Audi Denkwerkstatt: Which learnings could be transfered from agile start-ups to powertrain world?

Zusammenfassung

Audi Denkwerkstatt aims to develop new products and business models in the sector of mobility – beyond cars. As development of new business is the key asset of start-ups, Audi Denkwerkstatt is located in the heart of Berlin’s start-up ecosystem. A constant resident team of 8 people is offering an empowering platform and network, that enables batches of intrapreneurs throughout a 23 week process to develop new business models.

Matthias Brendel

Passenger Car Emissions and Consumption in Real Driving Conditions from the Point of View of Automobile Clubs

Zusammenfassung

The new exhaust emission standards Euro 6d temp and Euro 6d pose big challenges for car manufacturers. The vehicles tested by the automobile clubs in real driving conditions easily fulfil these stringent limit values. A simplified comparison is drawn with electric vehicles which show that the electricity generated in German power plants exceeds the measured emissions of Euro 6d temp and Euro 6d vehicles in terms of NO_x and particulate matter.

When comparing the greenhouse gas CO₂, electric cars perform better than cars with combustion engines due to their high efficiency.

Green NCAP was introduced to provide an evaluation of the environmental characteristics of passenger cars. Analogously to Euro NCAP, vehicles are given a rating of up to 5 stars, which is comprised of a Clean Air Index and an Emissions Efficiency Index.

It is essential to adopt a holistic CO₂ approach to vehicles that takes account of the individual stages of the life cycle: manufacture, fuel/energy provision, utilization and disposal. To this end a Life Cycle Analysis Tool was developed to examine the climate impact of various drives and fuel types.

Thomas Hametner, Lone Otto, Reinhard Kolke

Interaction and influence of HVO-based fuels on diesel combustion

Zusammenfassung

With a share of more than 20% of the total CO2 emissions of the European Union, both individual and freight traffic contribute significantly to climate change. Against the backdrop of the Paris agreement and global commitment to tackle climate change, new ways towards a CO₂-neutral mobility have to be identified. Most stakeholders in business, science and politics agree that no single key technology will be sufficient to address this issue but a range of technologies will be needed to develop the mobility of the future. One way to achieve CO₂ neutrality within the stock fleet is a symbiosis of conventional internal combustion engines and regenerative reFuels.

Especially with regard to the commercial vehicle market and the established diesel technology, the regenerative fuel named R33 (26% Hydrotreated Vegetable Oil (HVO), 7% Fatty Acid Methyl Ester (FAME), 67% diesel fuel) offers an adequate alternative to the conventional B7 as it fully complies with the requirements of the fuel standard DIN EN590. In addition to the sustainable production chain, one of the most important requirements for a regenerative fuel is its compatibility with the existing transport fleet (technical and emissions).

Against this backdrop we engaged in a holistic comparison between a conventional B7 winter diesel and a R33 regenerative fuel. The effects on the resulting emissions of a single-cylinder diesel engine for heavy commercial vehicle applications were analyzed at six stationary operating points, varying load and engine speed. Besides charting common combustion and emission parameters, we closely analyzed the resulting particulate emissions.

Daniel Erforth, Paul Lagaly, Thomas Koch

48 V hybrid system based on a switched reluctance motor for city busses

Zusammenfassung

Mild hybrid functions such as recuperation and start-stop offer signif-icant saving potential for improving the fuel consumption in city bus application with a good cost-benefit ratio. This potential is implemented by MAN in the new city bus with diesel (D15) and natural gas engine (E18) with a 48 V hybrid system in serial production. In both applications, a switched reluctance machine is used as a crankshaft starter alternator in P1 topology. For orientation of the control an algorithm is used and the control is therefore sensorless. The high starting power is provided by an Ultracap. A bidirectional DCDC is the interface to the 24 V on-board network and provides energy for that.

Markus Lampalzer, Michael Lechner

Electrified efficiency – diesel hybrid powertrain concepts for light commercial vehicles

Zusammenfassung

In the light commercial vehicle (LCV) segment, almost exclusively Diesel engines are used today. The reasons are high mileage, low real-world fuel consumption, high loading capacity and therefore low total cost of ownership. In the next decade, very demanding CO₂ targets as well as more stringent legal requirements for pollutant and noise emissions, especially in urban areas, require a substantial increase of electrified powertrain concepts. LCVs are typically employed for freight and passenger transport within urban areas, but are also used in interurban and/or motorway operation. These diverse cases of operation are often not suitable for full electric powertrain concepts, limiting their large-scale introduction. In this context, a Diesel Hybrid powertrain represents a highly capable and flexible propulsion system with attractively low real-world fuel consumption and the ability to achieve ultra-low pollutant emissions.

The potential of such a Diesel Hybrid powertrain for LCVs is investigated in a joint research project between FEV and VW. For this purpose, a demonstrator vehicle has been set-up with a P02 hybrid topology. The P02 hybrid topology is selected to be able to emulate different hybrid systems as well as different levels of hybridization from a 48V Mild Hybrid to a high voltage Plug-In Hybrid. The paper discusses future legal boundary conditions and describes the concept definition, the demonstrator vehicle setup as well as first vehicle results. The investigations are supported by simulation model calculations focusing on dedicated operating strategy optimization and an evaluation of the CO₂ and pollutant emission reduction potential for different use cases in the LCV segment.

Joschka Schaub, Martin Pieper, Stefan Klopstein, Matthias Übbing, Pascal Knappe, Paul Muthyala, Thorsten Schmidt

Renewable drop-in fuels as an immediate measure to reduce CO2 emissions of heavy-duty applications

Zusammenfassung

According to a report from the 2018 International Council on Clean Transportation, the transport sector alone is contributing 32 % of the total CO₂ emission in the European Union. Here, heavy duty vehicles are responsible for 25 % of the CO₂ emissions. The joint project “Robust and Efficient Processes and Technologies for Drop-In Renewable Fuels for Road Transport” (REDIFUEL) aims to produce an ultimate renewable drop-in biofuel, which is compliant with EN590 norms in a sustainable manner. In this project, a holistic fuel characterization is planned to assess the fuel characteristics and engine performance of this new paraffinic biofuel, consisting of about 30 vol% bio-alcohols. This work presents a first characterization and engine testing of a surrogate REDIFUEL mixture representative of the expected real end-product. Density, viscosity and cetane number of different blending proportion of this renewable fuel with diesel are screened, to assess its drop-in capability and the inherent impact on engine performance. With 40 vol% share of REDIFUEL in diesel, both the minimum EN590 requirements for cetane number and density are met. When this blend is compared against diesel, a relative reduction in indicated specific particulate matter, indicated specific carbon monoxide, indicated specific hydrocarbon and CO₂ emissions by 12 %, 6 %, 18 %, and 2.7 %, is respectively observed at a selected engine operated point. Numerical simulations show that blending REDIFUEL with diesel enhances the mixture formation, enabling a higher level of oxygen entrainment in the spray plume.

Jaykumar Yadav, Vikram Betgeri, Barbara Graziano, Avnish Dhongde, Benedikt Heuser, Markus Schönen, Nina Sittinger

Sustained CO2 reduction in vehicle traffic with renewable fuels

Zusammenfassung

Porsche is facing the challenge of achieving the Paris Agreement climate targets. Our new drive concepts focus in particular on electric mobility as a contributor to reducing greenhouse gas emissions. The new, pure-electric Taycan sends a clear signal in this regard.

Karl Dums, Hans-Peter Deeg, Marcos Remedios Marques, Andre Casal Kulzer, Dietmar Schwarzenthal

Life cycle assessment as a tool for analyzing the CO2 footprint of passenger cars with different powertrains

Zusammenfassung

In order to comply with increasingly strict CO₂ emission limits under tightened boundary conditions, automobile manufacturers rely more and more on electrified and purely electric powertrains. This trend can be explained by EU regulations, which do not attribute CO₂ emissions to battery electric vehicles (BEV), as BEVs do not cause local CO₂ emissions during the use phase. However, in order to evaluate the effective contribution of private transport to climate protection goals, a holistic system perspective on greenhouse gas emissions – i.e. cradle-to-grave instead of tank-to-wheel – is required.

In this regard, life cycle assessment (LCA) is an appropriate tool as it considers the entire product life cycle, which involves production, use and disposal/recycling of the product. Moreover, it allows the evaluation of different environmental impact categories, such as climate change (units of kg CO₂ equivalent), agricultural land occupation, natural land transformation, water depletion, etc.

Within this paper, a comprehensive and well-defined goal and scope phase of the LCA – different comparisons of passenger cars will be presented. This includes an internal combustion engine vehicle, both with conventional and renewable fuel, and a BEV, mainly with regard to greenhouse gas emissions as well as the aforementioned additional impact categories. Some of the most striking sensitivities are discussed, including the effect of the chosen amount of vehicle kilometers as a functional unit, the electricity mix in the production and use phase.

Philipp Weber, Jens Buchgeister, Olaf Toedter, Thomas Koch

Synthetic, regenerative fuels (reFuels) as enabler for climate neutral mobility and transport

Zusammenfassung

The use of synthetic, CO2-neutral fuels is one way to ensure a climate-neutral and low-emission transport in the future. OME has repeatedly proven to be an excellent alternative to conventional diesel fuel. The potential could already be demonstrated on the basis of various experimental setups on the engine testbeds as well as with the research vehicle at the Institute for Internal Combustion Engines and Powertrain Systems.

Alexander Mokros, Philipp Demel, Friedemar Knost, Markus Münz, Christian Beidl

Synthesis of Oxymethylene Ether (OME) – a 2nd generation E-fuel

Zusammenfassung

The reduction of CO₂ emission is one of the most important challenges regarding the Paris Agreement, which limits the increase of global warming to be below 2 °C or 1.5 °C respectively. [1] The mobility sector contributes with a share of 23 % largely to the global CO₂ emission. [2] One possibility to counteract this mobility based emission is the substitution of conventional fuels by sustainable synthetic fuels.

Andreas Peter, Harald Scherer, Eberhard Jacob, Ingo Krossing

Environmental assessment of OME3-5 synfuel production via the power-to-liquid pathway

Zusammenfassung

Oxymethylene Dimethyl Ethers (OME) are promising diesel fuel alternatives and interesting solvents for various industrial applications. In this report (Reproduced from [Hank et al. 2019] with permission from the Royal Society of Chemistry), a well-to-wheel Life Cycle Assessment of short OME oligomers as produced via a Power-to-Liquid (PtL) pathway has been conducted. Variations in electricity and carbon dioxide supply as well as the hardware demand for the PtL plant components (e.g. PEM water electrolysis, carbon capturing, 36 kta OME plant capacity) have been considered. Conventional diesel fuel is used as the comparative benchmark.

Christoph Hank, Lukas Lazar, Franz Kaspar Mantei, Mohamed Ouda, Robin J. White, Tom Smolinka, Achim Schaadt, Christopher Hebling, Hans-Martin Henning

Potential analysis and virtual development of SI engines operated with DMC+

Zusammenfassung

On the way to emission-free mobility, future fuels must be CO2 neutral. To achieve this, synthetic fuels are being developed. In order to better assess the effects of the new fuels on the engine process, simulation models are being developed that reproduce the chemical and physical properties of these fuels.

In this paper, the fuel DMC+ is examined. DMC+ (a mixture of dimethyl carbonate (DMC) and methyl formate (MeFo) mainly, characterized by the lack of C-C Bonds and high oxygen content) offers advantages with regard to evaporation heat, demand of oxygen and knock resistance. Furthermore, its combustion is almost particle free. With the aid of modern 0D/1D simulation methods, an assessment of the potential of DMC+ can be made.

It is shown that the simulative conversion of a state-of-the-art gasoline engine to DMC+ fuel offers advantages in terms of efficiency in many operating points even if the engine design is not altered. This is mainly due to the higher knock resistance and the lower temperatures in the intake stroke resulting from the higher amount of evaporated fuel. For a fixed amount of fuel energy, a lower air mass flow rate is needed, making the fuel particularly interesting for down-sizing concepts.

Therefore, the engine design is adapted for the new fuel to take full advantage of the fluid properties. In a first step, the adaptions include the compression ratio, the engine displacement and the turbocharger matching. A considerable efficiency gain in the whole operating range can be demonstrated, making DMC+ a highly promising prospective for future SI engines.

Cornelius Wagner, Michael Grill, Mahir-Tim Keskin, Liming Cai, Heinz Pitsch