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[ES] Este estudio está enfocado al análisis del potencial de nuevas arquitecturas de vehículos de pila de combustible (FCV) de H2 para incrementar el rendimiento y reducir las emisiones cradle-to-grave de gases de efecto invernadero (GHG-100) y NOx, con respecto a los FCV convencionales. Para ello, se llevarán a cabo tres estudios diferentes, cada uno correspondiente a una publicación distinta. En el primer estudio, se aplicará la metodología del análisis del ciclo de vida (LCA) para evaluar el H2 como combustible para reducir las emisiones GHG-100 y NOx en un proceso cradle-to-grave, comparado frente a vehículos con motor de combustión interna alternativo (ICEV) alimentados por combustibles fósiles y vehículos eléctricos de batería (BEV). Los resultados de este estudio mostrarán como los FCV podrían reducir las emisiones cradle-to-grave comparado con cualquier otra de las opciones consideradas en la actualidad y en el escenario de Europa en 2050, pero de ello depende de la estrategia de producción del H2. En este sentido, se recomienda el H2 azul, obtenido por reformado de gas metano (SMR) con captura de CO2 (CCS), por sus bajas emisiones en el proceso well-to-tank y la posibilidad que ofrece de su uso a gran escala y corto plazo. En el segundo estudio el rendimiento de la nueva arquitectura para vehículos de pasajeros FCREx, que emplea la pila de combustible (FC) como range-extender, se evaluará para diferentes combinaciones de máxima potencia de FC, capacidad de la batería y capacidad del tanque de H2. Para ello, se generarán espacios de diseño en función estos tres parámetros de dimensionamiento que muestren la autonomía, el consumo de energía total y de H2 para cada diseño. Con estos datos, se concluirá que esta arquitectura podría reducir el consumo de energía total hasta un 6.8% y el de H2 de un 16.8% a un 25%, comparada con diseños de FCV comerciales equivalentes en autonomía. El diseño FCREx óptimo debería tener una FC con una potencia máxima ≥80 kW y una capacidad de batería cercana a 30 kWh para minimizar tanto los costes de fabricación como el consumo, aunque el diseño óptimo, sólo en términos de consumo, sugiere que es más adecuado emplear baterías de mayor capacidad. El último estudio es una combinación de los dos primeros. En él se combinarán las metodologías de LCA y dimensionado para entender cómo cambian las emisiones GHG-100 y NOx en un proceso cradle-to-grave emitidas para FCVs con arquitectura FCREx cuando se modifican la potencia máxima de la FC, la capacidad de la batería y la capacidad el tanque de H2. A partir de los resultados de este estudio se concluirá que emplear H2 azul podría reducir las emisiones GHG-100 y NOx en un proceso cradle-to-grave en un 60% y 38% respectivamente, con respecto al H2 negro (obtenido por electrólisis empleando el mix energético europeo actual). El diseño óptimo, en términos de emisiones, es aquel con una capacidad de la batería baja-moderada y una potencia máxima de la FC moderada-alta, en contraste con el diseño óptimo sólo en términos de consumo. Finalmente, se sugiere que con el fin de minimizar las emisiones cradle-to-grave de los vehículos con arquitectura FCREx se debe priorizar la descarbonización del proceso de fabricación de las baterías, considerar el H2 azul como vector energético principal y aumentar la fracción de energía renovable en el mix energético europeo., [EN] This study is focused on analysing the potential of novel architectures for H2-based fuel cell vehicles (FCV) to improve the performance and cradle-to-grave greenhouse gases (GHG-100) and NOx emissions of conventional FCVs. To do so, three different studies will be carried out, each one corresponding to a different paper. In the first study, the life cycle assessment (LCA) methodology will be applied to evaluate H2 as a fuel to decrease cradle-to-grave GHG-100 and NOx emissions compared against hydrocarbon-fueld conventional internal combustion engine vehicles (ICEV) and battery electric vehicles (BEV). This study will show how FCV may decrease cradle-to-grave emissions compared to any of the other options in both the current and the EU 2050 scenarios, but it depends on the H2 production pathway. Blue H2, obtained from steam methane reforming (SMR) with carbon capture and storage (CCS), is recommended for its low well-to-tank emissions and the short-term massive application possibility. In the second study, the performance of the novel architecture for passenger vehicles FCREx, that uses the FC as a range-extender, will be evaluated for different combinations of FC maximum power, battery capacity and H2 tank capacity. Design spaces will be generated as a function of these sizing parameters to show the range, H2 consumption and total energy consumption of each design. In this study, it is concluded that this architecture could provide an overall energy saving consumption up to 6.8% and H2 consumption saving ranging from 16.8% to 25% compared to equivalent-in-range commercial FCV. The optimum FCREx design should have a FC maximum power of ≥80 kW and a battery capacity of ~30 kWh to minimize both manufacturing costs and consumption, although the optimum design, only in terms of consumption, suggested high battery capacity. The last study is a combination of the first and the second study. The LCA and sizing methodologies will be combined to understand how the cradle-to-grave GHG-100 and NOx emissions of the FCREx architecture change when the FC maximum power, the battery capacity and the H2 tank capacity change. From this study, it is concluded that considering blue H2 could decrease cradle-to-grave GHG-100 and NOx emissions by 60% and 38% with respect to black H2 (obtained through electrolysis from the current European electricity mix). The optimum design, in terms of emissions, is found to be with low-moderate battery capacity and moderate-high FC maximum power, in contrast to the optimum design in terms of performance only. Finally, with the produced data, it is suggested to prioritize the decarbonization of the battery manufacturing process, considering blue H2 as the main energy carrier and the increase in the renewable energy share in the EU electricity mix to minimize the cradle-to-grave emissions of FCREx vehicles.

Minimising tailpipe emissions and the decarbonisation of transport in a cost effective way remains a major objective for policymakers and vehicle manufacturers. Current trends are rapidly evolving but appear to be moving towards solutions in which vehicles which are increasingly electrified. As a result we will see a greater linkage between the wider energy system and the transportation sector resulting in a more complex and mutual dependency. At the same time, major investments into technological innovation across both sectors are yielding rapid advancements into on-board energy storage and more compact/lightweight on-board electricity generators. In the absence of sufficient technical data on such technology, holistic evaluations of the future transportation sector and its energy sources have not considered the impact of a new generation of innovation in propulsion technologies. In this paper, the potential impact of a number of novel powertrain technologies are evaluated and presented. The analysis considers heavy duty vehicles with conventional reciprocating engines powered by diesel and hydrogen, hybrid and battery electric vehicles and vehicles powered by hydrogen fuel cells, and free-piston engine generators (FPEGs). The benefits are compared for each technology to meet the expectations of representative medium and heavy-duty vehicle drivers. Analysis is presented in terms of vehicle type, vehicle duty cycle, fuel economy, greenhouse gas (GHG) emissions, impact on the vehicle etc.. The work shows that the underpinning energy vector and its primary energy source are the most significant factor for reducing primary energy consumption and net CO2 emissions. Indeed, while an HGV with a BEV powertrain offers no direct tailpipe emissions, it produces significantly worse lifecycle CO2 emissions than a conventional diesel powertrain. Even with a de-carbonised electricity system (100 g CO2/kWh), CO2 emissions are similar to a conventional Diesel fuelled HGV. For the HGV sector, range is key to operator acceptability of new powertrain technologies. This analysis has shown that cumulative benefits of improved electrical powertrains, on-board storage, efficiency improvements and vehicle design in 2025 and 2035 mean that hydrogen and electric fuelled vehicles can be competitive on gravimetric and volumetric density. Overall, the work demonstrates that presently there is no common powertrain solution appropriate for all vehicle types but how subtle improvements at a vehicle component level can have significant impact on the design choices for the wider energy system.

[EN] Fuel cell (FC) technologies for mobility are gaining interest as promising options to decarbonize the transport sector in line with the current progress towards the H-2 economy. Previous studies show how the fuel cell range extender (FCREx) powertrain architecture can offer flexible and efficient operation along with the potentially low total cost of ownership (TCO) in passenger car applications. Cradle-to-grave emissions of these vehicles have not been estimated, nor their variation with the components sizing or the H-2 production pathway analyzed. In this study, the life cycle assessment (LCA) and sizing methodologies were combined to address these knowledge gaps. The design spaces were generated by varying the FC maximum power, the battery capacity and the H-2 tank capacity and by simulating the resulting designs with the WLTC 3b driving cycle. Then, the lifetime H-2 and energy consumption results and design parameters were calculated and used as inputs to estimate the greenhouse gases (GHG) and NOX emissions on the manufacturing and fuel production cycles. From the results, it was proven how considering steam methane reforming (SMR) with carbon capture and storage (CCS) as the H-2 production pathway could decrease by 60% and 38% GHG-100 and NOX emissions respectively, with respect to electrolysis where electricity is generated with the EU mix. The optimum design, in terms of emissions, was found to be with low-moderate battery capacity and moderate-high FC maximum power in contrast to the optimum design for performance, which had high battery capacity and high FC stack power., This research has been partially funded by the Spanish Ministry of Science, Innovation and University through the University Fac-ulty Training (FPU) program (FPU19/00550) . Funding for open access charge: CRUE-Universitat Politecnica de Valencia

[EN] Aiming to reduce global warming and emissions in general, cleaner technologies are the spotlight of research and industry development. Among them, fuel cell vehicles (FCV) are gaining interest to decarbonize the transport sector. Plug-in FCV or FCV in range-extender configuration (FCREx) is an interesting option to reduce the total cost of ownership (TCO) and the energy usage per km. The aim of this study was to generate design spaces of FCREx by varying the FC stack maximum power output, the battery capacity, and the H-2 tank capacity to understand the implications of this architecture in range, consumption, and cost (estimated with a WLTP driving cycle). Unlike other studies, the approach was focused on a novel architecture for passenger vehicles and was focused on the development of the validated FC system model and the energy management strategy (EMS) optimization for each design, based on the Pontryagin Minimum Principle (PMP). Consumption was found to decrease with increasing battery capacity and FC maximum power due to the higher efficiency of the systems. The design spaces showed how with 5 kg of H-2 and >= 50 kWh of battery capacity the maximum range of FCREx could be over 700 km. The results of this study showed how FCREx architecture could provide overall energy consumption saving up to 6.8% and H-2 consumption saving ranging from 16.8% to 25%, compared to current commercial FCVs. The optimum FCREx design, not only based on performance, should have similar to 30 kWh of battery capacity and >= 80 kW of FC maximum power to minimize manufacturing costs while maximizing efficiency., This research has been partially funded by FEDER, Spain and the Spanish Government through project RTI2018-102025-B-I00 (CLEANFUEL) and through the University Faculty Training (FPU) program

Purpose: In the light of decarbonizing the passenger car sector, several technologies are available today. In this paper, we distinguish plug-in hybrid electric vehicles (PHEV), electric vehicles (EV) with a modest battery capacity of 40 kWh, and long-range EVs with 90 kWh installed. Given that the average motorist only rarely performs long-distance trips, both the PHEV and the 90 kWh EV are considered to be over-dimensioned for their purpose, although consumers tend to perceive the 40 kWh EV&rsquo, s range as too limiting. Therefore, in-life range modularity by means of occasionally using a range-extender trailer for a 40 kWh EV is proposed, based on either a petrol generator as a short-term solution or a 50 kWh battery pack. Method: A life cycle assessment (LCA) is presented for comparing the different powertrains for their environmental impact, with the emphasis on local air quality and climate change. Therefore, the combination of a 40 kWh EV and the trailer options is benchmarked with a range of conventional cars and EVs, differentiated per battery capacity. Next, the local impact per technology is discussed on a well-to-wheel base for the specific situation in Belgium, with specific attention given to the contribution of non-exhaust emissions of PM due to brake, tyre, and road wear. Results: From a life cycle point of view, the trailer concepts outperform the 90 kWh EV for the discussed midpoint indicators as the latter is characterized by a high manufacturing impact and by a mass penalty resulting in higher contributions to non-exhaust PM formation. Compared to a petrol PHEV, both trailers are found to have higher contributions to diminished local air quality, given the relatively low use phase impact of petrol combustion. Concerning human toxicity, the impact is proportional to battery size, although the battery trailer performs better than the 90 kWh EV due to its occasional application rather than carrying along such high capacity all the time. For climate change, we see a clear advantage of both the petrol and the battery trailer, with reductions ranging from one-third to nearly sixty percent, respectively. Conclusion: Whereas electrified powertrains have the potential to add to better urban air quality, their life cycle impact cannot be neglected as battery manufacturing remains a substantial contributor to the EV&rsquo, s overall impact. Therefore, in-life range modularity helps to reduce this burden by offering an extended range only when it is needed. This is relevant to bridge the years up until cleaner battery chemistries break through, while the energy production sector increases the implementation of renewables. Petrol generator trailers are no long-term solution but should be seen as an intermediate means until battery technology costs have further dropped to make it economically feasible to commercialize battery trailer range-extenders. Next, active regulation is required for non-exhaust PM emissions as they could dominate locally in the future if more renewables would be applied in the electricity production process.

Das Deutsche Zenrum für Luft- und Raumfahrt (DLR) erforscht einen Freikolbenlineargenerator (FKLG) mit Gasfeder. Erstmals wurde ein solches FKLG-Gesamtsystem in Betrieb genommen und die Machbarkeit des Konzepts nachgewiesen. Das System bietet interessante Potenziale als Range Extender im PKW-Antriebsstrang.

Nowadays, high-pressure gasoline direct injection (GDI) can be considered a standard technology, due to the wide application on 4-stroke turbocharged engines. This technology – in combination with other specific solutions - has been successfully applied to a 500 cc, 30 kW 2-stroke engine, initially developed as a range extender. The engine is valve-less and cam-less, being the scavenge and exhaust ports controlled by the piston. An electric supercharger delivers the required airflow rate, without need of a throttle valve; the lubrication is identical to a 4-stroke. The current study reviews the development process, assisted by CFD simulation, that has brought to the construction of a prototype, tested at the dynamometer bed of the University of Modena and Reggio Emilia (Engineering Department “Enzo Ferrari”). An experimentally calibrated CFD-1d model is applied to predict full load engine performance. The results show an excellent fuel efficiency and a very low level of thermal and mechanical stress despite the high power density.

Dissertation, RWTH Aachen University, 2017; Aachen : Fraunhofer VErlag, Wissenschaftliche Schriftenreihe des Fraunhofer ICT, 76, 1 Online-Ressource (X, 201 Seiten) : Illustrationen (2017). = Dissertation, RWTH Aachen University, 2017, The thesis deals with the design and build-up of a fuel cell system for an autonomous underwatervehicle (AUV). The utilized polymer electrolyte membrane fuel cell (PEMFC) is hybridized with the battery system in order to increase the mission duration and decrease the reloading time. The challenge in this work is to adapt the PEMFC system to a not foreseen environment while using a commercial fuel cell stack. In a first step, the boundary conditions for an operation under water and in the particular AUV have to be defined. In a second step, the development strategy has to be derived. In this sense, the state of the art of the individual subsystems is discussed. The most important system characteristic is the hindered mass transfer with the surrounding. As a result, a closed system with pure oxygen as an oxidant was developed. The inert gas intake, which resulted from impurities present in the gas bottles, had a strong influence on the design. As a consequence, operation time was reduced in a dead-end setup depending on the volume of the gas supply system. In the developed system an operation time of 1.8 hours was achieved. By using a recirculation on both gas sides the operation time could be further increased to a maximum of 71 hours. In the particular case, the available system volume was a restricting factor for the development of the system. The system volume was used as a primary design parameter. Afterwards, it was linked to further optimization parameters system stability, operation time and overall system efficiency. To reduce the system volume, gas conditioning was relinquished. The operation was validated by empiric measurements. Additionally, by using ejectors instead of compressors, the system volume could be reduced by 39 %.The influence of inert gases during dead-end operation of a closed fuel cell system was examined in an especially developed measuring setup. It could be shown, that a stable operation of the fuel cell system was possible up to an inert gas ratio of 3 %. With the designed dead-end-system a 24 hour operation was not possible. Therefore, gas recirculation was used on the cathodic as well as on the anodic side to allow a 24 hour operation. The developed system was assembled and tested in the laboratory. A stable operation of 8 hours was confirmed in an ex-situ measurement., Published by Fraunhofer VErlag, Aachen

Um die Grenzen der Traktions-Akkus zu überwinden, finden Range-Extender zunehmend Beachtung. Ein Forscherteam am DLR hat dafür einen Freikolbenlineargenerator entwickelt, der die Bewegungsenergie eines freischwingenden Kolbens einer Verbrennungskraftmaschine in elektrische Energie umwandelt. Als Höhepunkt der langjährigen Entwicklungsarbeit konnte das Team kürzlich den „Proof of Concept“ erbringen. Nun geht es um die Potenziale der Technologie sowie die offenen und die gelösten Herausforderungen.

In this work a research is presented aimed to improve the mechanical performance models used to establish a range-extension methodology, and to introduce the use of computational intelligence to operate a real-time range extension engine management system to replace the current algorithmic approach. This paper describes the initial stage in design of the control strategy, taking into account a number of environmental factors in order to increase the range of series hybrid electric vehicles.

Vorstellung des Freikolbenlineargenerators (FKLG)

Electric vehicles are emission free due to independence from fossil fuels and it has great advantage of environmental sustainability. Under the pressure of stringent emissions legislation in the future, electrification of the drive train is an option in order to meet the emission standards law. Even though the battery technology has advanced greatly during the past decade, it still has some limitations. One limitation is the range, which would make only possible to use an electric vehicle in the urban traffic. An owner of a conventional vehicle is usually not having different vehicles for various applications such as driving to work, shopping, holidays, etc. In the case of the fuel cell range extender concept, as shown in figure 1, is an attractive way, which combine both technologies either permanently or on demand and also promotes the introduction of e-mobility as a sustainable vehicle concept. The on-board fuel cell charging system could also carry the tasks of heat management and the air conditioning, which requires new and innovative concepts, so that the range of the electric vehicle could be increased. In this mentioned range extender vehicle concept, the powertrain is driven mainly by the high performance Li-ion battery. In this project, the variant of lithium iron phosphate Li-FePO4 battery has been used. The on-board fuel cell range extender in this case serves as an additional source of energy unit, which charge the high-performance battery in a low SOC and therefore extend the range. The design of such a vehicle concept is nowadays trend of technology therefore a simulation tool plays a very important role, which allows the prediction of the design. The role of the battery as opposed to the conventional vehicle acts here as the main energy storage, and therefore a study of the essential behavior of the battery must be done. The modeling of the battery was performed partially map-based, which enables a simpler parameterization. Besides the energetic behavior, the thermal behavior also would be described in the model, which is completed by the measurement of the temperature dependent charge and discharge behavior. A comprehensive survey of the behavior of the battery could be done by the integration to the full vehicle model, which are included an on-board fuel cell range extender, power electronics, electric motor, drive train, chassis, and controller cycles. The simulation results could be used as a tool for optimum design for range extender vehicle concepts as shown in the figure 1. A final validation of the complete vehicle model would be done by comparison between the simulation results of the full vehicle model and the results of the driving behavior of the real prototype vehicle on chassis dynamometer.