Wasserstoff
Wasserstoff weist als zukünftiger Energieträger einige Vorteile auf. Es ist das am häufigsten in der Natur vorkommende Element – die meisten Fixsterne bestehen Großteils aus Wasserstoff – und ist somit theoretisch unbegrenzt verfügbar.
EIGENSCHAFTEN
Wasserstoff ist bei Zimmertemperatur ein farb- und geruchloses Gas, das ca.14,4mal leichter als Luft ist. Es ist das Element mit der geringsten Dichte, daher diffundiert Wasserstoff leicht durch poröse Trennwände, aber auch durch Metalle wie Platin. Das Element Nr. 1 hat nach Helium die tiefste Schmelz- und Siedetemperatur. In der Regel kommt Wasserstoff in einer zweiatomigen Molekülform vor (H2). Es existieren drei natürliche Isotope: Ein normales Wasserstoffatom (Isotop Protium) besteht aus einem Proton und einem Elektron. Dagegen besitzt schwerer Wasserstoff (Isotop Deuterium) zusätzlich ein Neutron und überschwerer Wasserstoff (Isotop Tritium) zwei Neutronen. Das Isotop Deuterium hat im natürlichen Wasserstoff einen geringen Anteil von ca. 0,015%. Während reiner Wasserstoff für den menschlichen Organismus nicht giftig wirkt, gelten der schwere Wasserstoff und das schwere Wasser (Deuteriumoxid) als stark giftig.
Wasserstoffatome kommen in gebundener Form in zahlreichen Verbindungen vor, z.B. in Wasser oder in organischen Verbindungen wie Kohlenwasserstoffen (Methan, Ethan, Benzol), Alkoholen (Methanol, Ethanol), Aldehyden, Säuren, Fetten, Kohlenhydraten und Eiweißen. Wasserstoffatome sind im menschlichen Körper sehr häufig vertreten und an vielen wichtigen Stoffwechselprozessen wie der Verdauung beteiligt.
Wasserstoffmoleküle treten in zwei verschiedenen chemischen Zuständen auf, Ortho- und Para-Wasserstoff. Diese unterscheiden sich in der Orientierung ihres atomaren Spins. Der Spin bezeichnet den Drehimpuls der Elementarteilchen eines Atoms. Ortho-Wasserstoff weist einen parallel Spin auf, während Para-Wasserstoff über einen antiparallelen Spin verfügt. Para-Wasserstoff hat eine geringere spezifische Wärmekapazität als Ortho-Wasserstoff. Bei Umgebungstemperatur kommt Ortho-Wasserstoff dreimal häufiger vor als Para-Wasserstoff. Ein Gemisch aus 25% Para- und 75% Ortho-Wasserstoff wird Normal-Wasserstoff (n-H2) genannt. Unterhalb von –200 °C liegt fast ausschließlich Para-Wasserstoff vor. Das Gemisch aus Para- und Ortho-Wasserstoff, das sich entsprechend dem jeweiligen thermodynamischen Zustand einstellt, wird Gleichgewichts-Wasserstoff genannt. Die Umwandlung von einem zum anderen Zustand ist ein langsamer Prozess, der sich ohne die Anwesenheit von Katalysatoren über mehrere Tage hinstrecken kann. Mittels magnetokalorischer Verfahren kann eine Umwandlung von Ortho- in Para-Wasserstoff in mehreren Stufen erfolgen, bis ein Para-Wasserstoffgehalt von über 95 % erreicht ist.
An der Luft verbrennt Wasserstoff mit einer schwach bläulichen Flamme zu Wasser:
2 H2 + O2 =>2 H2O H = 572 kJ/mol
Gemische mit Sauerstoff oder mit Chlorgas explodieren bei Zündung sehr heftig und werden als Knallgas-Gemische bezeichnet. Im Labor erfolgt der Nachweis von Wasserstoff mit der Knallgasprobe. Diese Probe dient auch zur Überprüfung, ob in einem Gas ein Knallgasgemisch vorliegt. Ertönt ein lauter pfeifender Knall, handelt es sich um Knallgas, bei einem harmlosen, dumpfen Geräusch ist nur reiner Wasserstoff im Reagenzglas. Mit Alkali- oder Erdalkalimetallen bildet Wasserstoff in exothermen Reaktionen Hydride.
HERSTELLUNG
Zur Herstellung von Wasserstoff sind eine Reihe von Verfahren im Einsatz. Da Wasserstoff in der Natur nur in gebundener Form vorkommt, ist zu seiner Gewinnung der Einsatz von Primärenergie erforderlich. Weltweit werden etwa 500 Mrd. Normkubikmetern Wasserstoff pro Jahr umgesetzt, 40 % davon fallen in der chemischen Industrie als Nebenprodukt an, etwa bei der Herstellung von Chlor mittels der Chlor-Alkali-Elektrolyse oder aus Rohölraffinerieprozessen. Etwa 20% des Wasserstoffs werden zur Energieerzeugung verwendet.
Der weitaus größte Teil des erzeugten Wasserstoffs stammt aus fossilen Energiequellen, aus der katalytischen Dampfspaltung von Methan (Erdgasreformierung), der partiellen Oxidation von Schweröl (Diesel) oder der Vergasung von Kohle. Bei diesen auf kohlenstoffhaltigen Ausgangskomponenten basierenden Herstellungsverfahren entsteht CO2. Die Herstellung von Wasserstoff durch Elektrolyse von Wasser, das mit Natronlauge oder Schwefelsäure elektrisch leitfähig gemacht wurde, erlaubt bei Nutzung von Wind- Wasser- oder Sonnenenergie eine regenerierbare emissionsfreie Energiekette. Ebenso emissionsfrei aber teuer lässt sich Wasserstoff aus einer Reihe chemischer Reaktionen mit Wasser gewinnen, etwa aus der Reaktion von Alkalimetallen und Wasser. Weitere Herstellungsverfahren befinden sich im Forschungs- und Entwicklungsstadium, wie die autotherme Reformierung, das Kværner-Verfahren, die Vergasung von Biomasse oder organischen Abfällen sowie die Hochdruckelektrolyse. Ebenfalls erforscht werden Verfahren zur Wasserstoffgewinnung durch biologische Prozesse.
SPEICHERUNG
Aufgrund der geringen Dichte des Wasserstoffs stellt die Speicherung bei ausreichender Energiedichte technische und wirtschaftliche Herausforderungen dar. Üblich sind Verfahren wie die Speicherung von verdichtetem gasförmigem Wasserstoff, tiefkalt flüssigen Wasserstoff und die Speicherung von Wasserstoff in chemischen oder physikalischen Verbindungen.
Gasförmiger Wasserstoff wird auf Drücke von 200 bar bis 900 bar hoch verdichtet und als CGH2 (compressed gaseous hydrogen) in Druckbehältern gespeichert. Es gibt 4 Arten von Druckbehälter die von einfachen Stahlflaschen bis hin zu Vollverbundflaschen (CFK) reichen.
Um höhere Energiedichten zu erreichen, wird Wasserstoff verflüssigt und als LH2 (liquid hydrogen) tiefkalt gelagert. Da die Kondensation von Wasserstoff bei Umgebungsdruck erst bei -252,85 °C eintritt, ist der Aufwand für die Verflüssigung hoch und muss energetisch optimiert werden.
Leider hat sich in der Vergangenheit das Gerücht etabliert, dass Wasserstoff nicht dauerhaft speicherbar ist. Dies bezieht sich ausschließlich auf die Speicherung als tiefkalten Flüssigwasserstoff, weil dieser verdampft und abgeblasen wird (Boil off). Seit Jahrzehnten wird Wasserstoff in Bündeln (Gestell bestehend aus 12 Gasflaschen) abgefüllt und so auf Dauer gespeichert und gelagert. Des Weiteren kann Wasserstoff wie im Projekt W2H in die Erdgasleitung miteingespeist werden (unter Berücksichtigung des gesetzlich vorgeschriebenen Maximalanteils) und so das Erdgasnetz als Speicher verwenden.
ANWENDUNG
Unsere heutige Energieversorgung basiert hauptsächlich auf der Nutzung von begrenzt vorhandenen Vorräten an fossilen Brennstoffen, die aus einer Reihe kurz- bis langkettiger Kohlenwasserstoff-Verbindungen bestehen. Die Energiegewinnung durch Verbrennung kohlenwasserstoffhaltiger Substanzen in Luft, die seit der Nutzbarmachung des Feuers die technische Entwicklung der Menschheit begleitet, verursacht verfahrensbedingt die Bildung des Treibhausgases Kohlendioxid und verschiedener Schadstoffe wie Kohlenwasserstoffe, Stickoxide und Ruß.
Wasserstoff kann in Verbrennungskraftmaschinen weitgehend schadstofffrei verbrannt werden, es entstehen weder Kohlenmonoxid, Kohlendioxid noch Kohlenwasserstoffe, die Emission von Stickoxiden kann gering gehalten werden. Nutzt man Wasserstoff in einer Brennstoffzelle, liefert er in einer „kalten Verbrennung“ elektrische Energie ohne die Abgabe von Schadstoffen oder Lärm. Um Wasserstoff als Energieträger zur Stromerzeugung in Brennstoffzellen oder als Fahrzeugantrieb in Brennstoffzellen oder in Verbrennungskraftmaschinen industriell nutzbar zu machen, sind jedoch noch eine Reihe wirtschaftlicher und technischer Fragen zu lösen.
Literatur
Wissenschaftliche Publikationen
Sustainable hydrogen society – Vision, findings and development of a hydrogen economy using the example of Austria
Autoren: Trattner, Alexander; Klell, Manfred; Radner, Fabian
Abstract: Based on technical, environmental, economic and social facts and recent findings, the feasibility of the transition from our current fossil age to the new green age is analyzed in detail at both global and local level. To avert the threats of health problems, environmental pollution and climate change to our quality and standard of life, a twofold radical paradigm shift is outlined: Green Energy Revolution means the complete change from fossil-based to green primary energy sources such as sun, wind, water, environmental heat, and biomass; Green Hydrogen Society means the complete change from fossil-based final energy to green electricity and green hydrogen in all areas of mobility, industries, households and energy services. Renewable energies offer a green future and are in combination with electrochemical machines such as electrolysers, batteries and fuel cells able to achieve higher efficiencies and zero emissions.
Link: Link
Exergy as Criteria for Efficient Energy Systems – Maximising Energy Efficiency from Resource to Energy Service, an Austrian Case Study
Autoren: Sejkora, Christoph; Kühberger, Lisa; Radner, Fabian; Trattner, Alexander; Kienberger, Thomas
Abstract: The EU aims for complete decarbonisation. Therefore, renewable generation must be massively expanded, and the energy and exergy efficiency of the entire system must be significantly increased. To increase exergy efficiency, a holistic consideration of the energy system is necessary. This work analyses the optimal technology mix to maximise exergy efficiency in a fully decarbonised energy system. An exergy-based optimisation model is presented and analysed. It considers both, the energy supply system and the final energy application. The optimisation is using Austria as a case study with targeted renewable generation capacities of 2030. The results show, that despite this massive expansion and the maximum exergy efficiency, about half of the primary energy still be imported. Overall exergy efficiency can be raised from today's 34% (Sejkora et al., 2020) to 56%. The major increase in exergy efficiency is achieved in the areas of heat supply (via complete excess heat utilisation and heat pumps) and transport (via electric and fuel cell drives). The investigated exergy optimisation results in an increase of the final electrical energy demand by 44% compared to the current situation. This increase leads to mainly positive residual loads, despite a significant expansion of renewable generation. Negative residual loads are used to provide heat and hydrogen.
Link: Link
Renewable Hydrogen: Modular Concepts from Production over Storage to the Consumer
Autoren: Trattner, Alexander; Höglinger, Martin; Macherhammer, Marie‐Gabrielle; Sartory, Markus
Abstract: A simulation tool called HYDRA to optimize individual hydrogen infrastructure layouts is presented. The different electrolyzer technologies, namely proton exchange membrane electrolysis, anion exchange membrane electrolysis, alkaline electrolysis, and solid oxide electrolysis, as well as hydrogen storage possibilities are described in more detail and evaluated. To illustrate the application opportunities of HYDRA, three project examples are discussed. The examples include central and decentral applications while taking the usage of hydrogen into account.
Link: Link
Capabilities and Limitations of 3D-CFD Simulation of Anode Flow Fields of High-Pressure PEM Water Electrolysis
Autoren: Haas, Christoph; Macherhammer, Marie-Gabrielle; Klopcic, Nejc; Trattner, Alexander
Abstract: In this work, single-phase (liquid water) and two-phase (liquid water and gaseous oxygen) 3D-CFD flow analysis of the anode of a high pressure PEM electrolysis cell was conducted. 3D-CFD simulation models of the anode side porous transport layer of a PEM electrolyzer cell were created for the flow analysis. For the geometrical modelling of the PTL, two approaches were used: (a) modelling the exact geometry and (b) modelling a simplified geometry using a porosity model. Before conducting two-phase simulations, the model was validated using a single-phase approach. The Eulerian multiphase and the volume-of-fluid approaches were used for the two-phase modelling and the results were compared. Furthermore, a small section of the PTL was isolated to focus on the gas bubble flow and behaviour in more detail. The results showed plausible tendencies regarding pressure drop, velocity distribution and gas volume fraction distribution. The simplified geometry using the porous model could adequately replicate the results of the exact geometry model with a significant reduction in simulation time. The developed simulation model can be used for further investigations and gives insight into two-phase flow phenomena in the PTL. Additionally, the information obtained from simulation can aid the design and evaluation of new PTL structures.
Link: Link
Quasi-stationary UI-characteristic model of a PEM fuel cell–Evaluating the option of self-humidifying operation
Autoren: Wallnöfer-Ogris, Eva; Pertl, Patrick; Trattner, Alexander
Abstract: This work presents a zero-dimensional PEM fuel cell UI-characteristic model created in MATLAB Simulink® for operation with dry or humidified air supply. It is parameterised and validated based on the results of stack operation by varying stack temperature (50–80 °C), gas pressure (1.0–2.4 bar) and air humidification (0.0–1.0). The model is based on physical and electrochemical correlations and expanded by empirically assumptions concerning the influence of the humidification and limiting current density on the performance. The UI-model is intended to be integrated into a comprehensive zero-emission powertrain model. Since non-humidified operation of PEM fuel cell systems provides benefits for mobile applications by reducing space demand and system complexity, the objective of the model is to relate performance to the operating conditions and underlying physical parameters. Results confirm the feasibility of a self-humidifying stack operation at high performance by optimal parameter setting.
Link: Link
Advanced Methods of Optimising Fuel Cells on System Testbed
Autoren: Trattner, Alexander; Brandstätter, Stefan; Pertl, Patrick; Dehne, Thomas; Kügele, Christoph; Paulweber, Michael
Abstract: A clear transition from carbon-based energy sources and energy carriers towards renewable and carbon-free energy carriers is necessary in order to meet the climate goals set in the Climate Change Conference in Paris 2015. Hence, the consistent decarbonisation of all sectors of our economy is mandatory, e.g. in mobility and transport, for households and in industry. Electricity and hydrogen are the only two energy carriers that can be produced and used in an emission-free cycle. Particularly in mobility and road transport, battery electric vehicles for short range and fuel cells electric vehicles for long range and fast refuelling are offering the possibility for a complete decarbonisation. When high driving range is required, fuel cell vehicles achieve lower costs at high production volume compared to battery electric vehicles. Moreover, fuel cell vehicles feature significant advantages regarding rare resources and recycling. However, high improvement potentials especially concerning overall efficiency, costs, industrialisation, materials etc. are still existing.
As a starting point this paper provides an overview of the status of technology of fuel cells and hydrogen in mobility and road transport. Regarding efficiency analyses, the focus is put on a novel method for evaluating the fuel cell system efficiency using energy and exergy analyses. This innovative approach is based on sophisticated exergy analyses to determine efficiency potentials from fuel cell stack up to fuel cell system level including the auxiliaries - BoP components. In addition, the results are structured into physical, chemical and kinetic efficiency potentials. In this context examples for passenger car as well as for heavy duty applications are presented. As the thermal management of FC propulsion systems is decisive for enabling high efficiencies this method further allows detailed thermodynamic investigations for a single competent as well as for entire propulsion systems on a scientifically established basis. Furthermore, the well-to-wheel as well as life-cycle CO2 emissions of FCEVs in comparison to other powertrains are analysed. This comparison includes passenger cars, busses and trucks.
Link: Konferenz-Link
Exergy as Criteria for Efficient Energy Systems
A Spatially Resolved Comparison of the Current Exergy Consumption, the Current Useful Exergy Demand and Renewable Exergy Potential
Autoren: Christoph Sejkora, Lisa Kühberger, Fabian Radner, Alexander Trattner and Thomas Kienberger
Abstract: The energy transition from fossil‐based energy sources to renewable energy sources of an industrialized country is a big challenge and needs major systemic changes to the energy supply. Such changes require a holistic view of the energy system, which includes both renewable potentials and consumption. Thereby exergy, which describes the quality of energy, must also be considered. In this work, the determination and analysis of such a holistic view of a country are presented, using Austria as an example. The methodology enables the calculation of the spatially resolved current exergy consumption, the spatially resolved current useful exergy demand and the spatially resolved technical potential of renewable energy sources (RES). Top‐down and bottom‐up approaches are combined in order to increase accuracy. We found that, currently, Austria cannot self‐supply with exergy using only RES. Therefore, Austria should increase the efficiency of its energy system, since the overall exergy efficiency is only at 34%. The spatially resolved analysis shows that in Austria the exergy potential of RES is rather evenly distributed. In contrast, the exergy consumption is concentrated in urban and industrial areas. Therefore, the future energy infrastructure must compensate for these spatial discrepancies.
Link: doi:10.3390/en13040843
Development of Hydrogen Powered Fuel Cell e-Snowmobiles
Autoren: Patrick Pertl, Martin Aggarwal, Alexander Trattner, Walter Hinterberger, Nigel Foxhall
Abstract: In the highly innovative and holistic flagship project HySnow (Decarbonisation of Winter Tourism by Hydrogen Powered Fuel Cell Snowmobiles), funded by the Austrian Climate and Energy Fund, the decarbonization of winter tourism is being demonstrated. Within this project, two prototype e-snowmobiles have been developed including the adaption of a Polymer Electrolyte Membrane Fuel Cell (PEM-FC) system for the low temperature and high-performance targets and the integration of the drivetrain into the vehicle. In this paper the drivetrain development process of the prototype e-snowmobiles will be presented with the aim to derive specifications for the drivetrain components as PEM-FC system, hydrogen storage system, electric drive, battery and power electronics. Based on typical use cases for snowmobiles overall vehicle specifications and requirements are defined. Associated driving cycles are investigated and used as input for the development process. Subsequently, analyses regarding possible drivetrain topologies based on technical and economical vehicle requirements are carried out. In parallel, vehicle implementation concepts based on standardized development processes are performed. The development and the design process are verified by verification and optimization loops. The results define technical specifications of the PEM-FC, the battery along with the required hydrogen tank; to give an optimum concerning required drivetrain efficiency, and hence driving range as well as vehicle space and weight. It is expected that the hydrogen powered e-snowmobiles with high power, drivability, driving fun, and the lack of noise emission, pollutants, and GHG will convince the users of the concept benefits.
Link: SAE Mobilus
A novel approach for dynamic gas conditioning for PEMFC stack testing
Autoren: Janos Kancsar, Michael Striednig, David Aldrian, Alexander Trattner, Manfred Klell, Christoph Kügele, Stefan Jakubek
Abstract: The air supply to the polymer electrolyte membrane fuel cell (PEMFC) stack is crucial for the performance of a PEMFC system. To enable modular and transient testing of the stack during development, a novel dynamic gas conditioning system is presented. To meet the requirements of transient stack testing, different hardware concepts for the testbed are evaluated and an experimental setup is realised. The thermodynamic states of this system are coupled through various relations and represent a nonlinear multivariate control problem. For controller design a dynamic nonlinear model of the system is derived and parameterised with measurements from the testbed. To decouple the system and achieve a good transient response the model-based nonlinear control concept of exact inputoutput linearisation is applied. Based on the decoupled system, a Two-Degree-of-Freedom (2DoF) controller is designed. The application of this nonlinear control concept on the realised hardware setup shows that accurate trajectory tracking during dynamic set point changes is ensured. Experimental results are presented to validate the control performance.
Modular Concept of a Cost-Effective and Efficient On-Site Hydrogen Production Solution
Autoren: Markus Sartory, Markus Justl, Patrick Salman, Alexander Trattner, Manfred Klell
Abstract: Hydrogen as carbon-free energy carrier, produced from renewable sources like wind, solar or hydro power, is a promising option to overcome the impacts of the anthropogenic climate change. Recently, great advances regarding the early market introduction of FCVs have been achieved. As the availability of hydrogen refueling stations is highly limited, a modular, scalable and highly efficient hydrogen supply infrastructure concept is presented in this paper. The focus lies on cost-effectiveness and flexibility for the utilization in different applications and for growing markets. Based on the analysis of different use cases, the requirements for the newly developed concept are elaborated. The modular system design, utilizing a standardized high pressure PEM electrolysis module, allows a scalable hydrogen production of up to several hundred kilograms per day. The high pressure electrolyzer produces hydrogen at 35 MPa without mechanical compression and offers the following benefits: highest system efficiencies, dynamic operational behavior, good partial load behavior, low maintenance efforts and highest hydrogen qualities. Refueling processes at both standardized filling pressures, 35 MPa and 70 MPa, can be realized. A major advantage of the modular concept is the capability of a subsequent extension in order to adapt the infrastructure to growing demands. The developed concept represents an important factor for the market penetration of hydrogen technologies as the utilization of a standardized electrolysis module will lead to significant cost reductions as of increasing production figures. Three implementation concepts with different hydrogen capacities are presented: a small-sized infrastructure for home refueling with 1.5 kg/d, a medium-sized infrastructure for industrial utilization with up to 50 kg/d and a large-sized infrastructure with more than 100 kg/d.
Hydrogen-Powered Fuel Cell Range Extender Vehicle - Long Driving Range with Zero-Emissions
Autoren: Patrick Salman, Eva Wallnöfer-Ogris, Markus Sartory, Alexander Trattner, Manfred Knell
Abstract: The continuous increasingly stringent regulations for CO2 fleet targets request the introduction of zero-emission solutions in the near future. Moreover, additional customer benefits have to be generated in order to increase customer acceptance of zero-emission technologies. Actually high costs, reduced driving ranges and lack of infrastructures are some aggregative facts for end-customer acceptance thus also for a broad market launch. Plug-in hybrids as intermediate step towards zero-emission vehicles are meanwhile in series production with partly “zero-emission” operation mode and are well accepted by customers. The project partners HyCentA Research GmbH, Magna Steyr Engineering AG & Co KG, Proton Motor Fuel Cell GmbH and the Vienna University of Technology, Institute for Powertrains and Automotive Technology, have developed a hydrogen-powered zero-emission vehicle within a national funded research project. The combustion engine of an existing range extender shuttle van was substituted by a 25 kW proton-exchange-membrane fuel cell system. In addition, the battery capacity was reduced due to weight, size and costs reasons. Approaches for the complete vehicle integration of the fuel cell range extender and the 70 MPa hydrogen storage system are presented. The high voltage architecture was newly developed and the thermal management has been re-designed. A two circuit coolant system fulfills the wide range of component demands with the possibility of fuel cell waste heat usage for cabin heating. Influences of the operation strategy on the energy and cost efficiency of the vehicle are shown and the optimization potentials will be outlined. The adaptive energy management algorithm and its influence on the fuel efficiency and driving range will be presented. Overall, the vehicle setup combines the advantages of the battery and the fuel cell technology to compensate shortcomings like refueling duration, driving range and dynamic operation.
Theoretical and experimental analysis of an asymmetric high pressure PEM water electrolyser up to 155 bar
Autoren: Sartory, Markus; Wallnöfer-Ogris, Eva; Salman, Patrick; Fellinger, Thomas; Justl, Markus; Trattner, Alexander; Klell, Manfred
Abstract: The continuous increasingly stringent regulations for CO2 fleet targets request the introduction of zero-emission solutions in the near future. Moreover, additional customer benefits have to be generated in order to increase customer acceptance of zero-emission technologies. Actually high costs, reduced driving ranges and lack of infrastructures are some aggregative facts for end-customer acceptance thus also for a broad market launch. Plug-in hybrids as intermediate step towards zero-emission vehicles are meanwhile in series production with partly “zero-emission” operation mode and are well accepted by customers. The project partners HyCentA Research GmbH, Magna Steyr Engineering AG & Co KG, Proton Motor Fuel Cell GmbH and the Vienna University of Technology, Institute for Powertrains and Automotive Technology, have developed a hydrogen-powered zero-emission vehicle within a national funded research project. The combustion engine of an existing range extender shuttle van was substituted by a 25 kW proton-exchange-membrane fuel cell system. In addition, the battery capacity was reduced due to weight, size and costs reasons. Approaches for the complete vehicle integration of the fuel cell range extender and the 70 MPa hydrogen storage system are presented. The high voltage architecture was newly developed and the thermal management has been re-designed. A two circuit coolant system fulfills the wide range of component demands with the possibility of fuel cell waste heat usage for cabin heating. Influences of the operation strategy on the energy and cost efficiency of the vehicle are shown and the optimization potentials will be outlined. The adaptive energy management algorithm and its influence on the fuel efficiency and driving range will be presented. Overall, the vehicle setup combines the advantages of the battery and the fuel cell technology to compensate shortcomings like refueling duration, driving range and dynamic operation.
Highly Integrated Fuel Cell Analysis Infrastructure for Advanced Research Topics
Autoren: Stefan Brandstätter, Michael Striednig, David Aldrian, Alexander Trattner, Manfred Klell
Abstract: The limitation of global warming to less than 2 °C till the end of the century is regarded as the main challenge of our time. In order to meet COP21 objectives, a clear transition from carbon-based energy sources towards renewable and carbon-free energy carriers is mandatory. Polymer electrolyte membrane fuel cells (PEMFC) allow an energy-efficient, resource-efficient and emission-free conversion of regenerative produced hydrogen. For these reasons fuel cell technologies emerge in stationary, mobile and logistic applications with acceptable cruising ranges as well as short refueling times. In order to perform applied research in the area of PEMFC systems, a highly integrated fuel cell analysis infrastructure for systems up to 150 kW electric power was developed and established within a cooperative research project by HyCentA Research GmbH and AVL List GmbH in Graz, Austria. A novel open testing facility with hardware in the loop (HiL) capability is presented. Vehicle, driver and driving cycle as well as powertrain components like battery, electric engine, transmission and different balance of plant (BoP) components can be simulated in real time. Ambient conditions and media supply temperatures can be adjusted dynamically in the range of –40 °C to 85 °C. Moreover, cathode air humidity can be varied in the range of 5 % to 95 %. The test bed allows research and development on topics from energy management to thermal management, from complete vehicle to sub-system control and calibration, from vehicle integration to the investigation of dynamics, cold start and lifetime.
Fuel cell range extended electric vehicle FCREEV long driving ranges without emissions
Autoren: Mueller, Helfried; Bernt, Axel-Oscar; Salman, Patrick; Trattner, Alexander;
Abstract: The limitation of global warming to less than 2 °C till the end of the century is regarded as the main challenge of our time. In order to meet COP21 objectives, a clear transition from carbon-based energy sources towards renewable and carbon-free energy carriers is mandatory. Polymer electrolyte membrane fuel cells (PEMFC) allow an energy-efficient, resource-efficient and emission-free conversion of regenerative produced hydrogen. For these reasons fuel cell technologies emerge in stationary, mobile and logistic applications with acceptable cruising ranges as well as short refueling times. In order to perform applied research in the area of PEMFC systems, a highly integrated fuel cell analysis infrastructure for systems up to 150 kW electric power was developed and established within a cooperative research project by HyCentA Research GmbH and AVL List GmbH in Graz, Austria. A novel open testing facility with hardware in the loop (HiL) capability is presented. Vehicle, driver and driving cycle as well as powertrain components like battery, electric engine, transmission and different balance of plant (BoP) components can be simulated in real time. Ambient conditions and media supply temperatures can be adjusted dynamically in the range of –40 °C to 85 °C. Moreover, cathode air humidity can be varied in the range of 5 % to 95 %. The test bed allows research and development on topics from energy management to thermal management, from complete vehicle to sub-system control and calibration, from vehicle integration to the investigation of dynamics, cold start and lifetime.
Thermodynamic real gas analysis of a tank filling process
Autoren: Striednig, Michael; Brandstätter, Stefan; Sartory, Markus; Klell, Manfred
Abstract: A zero-dimensional thermodynamic real gas simulation model for a tank filling process with hydrogen is presented in this paper. Ideal gas and real gas simulations are compared and the entropy balance of the filling process is formulated. Calculated results are validated for a type I tank (steel vessel) with measurements. The simulation is used to accurately predict the maximum gas temperature during the refueling of pressurized gaseous hydrogen storages, which must not exceed 85 °C according to international standards. The influences of ambient temperature, initial pressure and pressure ramp rate on the resulting hydrogen gas temperature in the tank are investigated. In experiments, the effect of pressure pulses applied in practice on the resulting gas temperature is investigated as is the influence of the Joule–Thomson effect of hydrogen and methane. Finally simulations and experimental results are used to develop a refueling protocol for hydrogen powered industrial trucks, in operation at Europe's first indoor hydrogen filling station in Linz, Austria.
Fachbücher
Wasserstoff in der Fahrzeugtechnik
Erzeugung, Speicherung, Anwendung
Zusammenfassung: Dieses Buch bietet einen allgemeinen Überblick über die verschiedenen Aspekte von Eigenschaften, Erzeugung, Speicherung und Anwendung von Wasserstoff. Schwerpunkte liegen auf der Thermodynamik von Wasserstoff sowie auf dessen Anwendung in der Fahrzeugtechnik und in der Energietechnik. Mit Bezug zu Forschungsvorhaben an der Technischen Universität Graz und dem HyCentA, Hydrogen Center Austria, wird der aktuelle Stand der Technik fundiert dargestellt. Aktualisiert und ergänzt wurden vor allem die Abschnitte über die Elektrolyse zur Erzeugung von Wasserstoff aus grünem Strom und über Brennstoffzellen zur Stromerzeugung für Elektroantriebe.
Autoren: Klell, Manfred; Eichlseder, Helmut; Trattner, Alexander
ISBN: 365820446X