Energie-Umweltmanagement
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Browsing Energie-Umweltmanagement by Department "Forschung Burgenland"
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- PublicationAssessing the technical feasibility of value chains for Reed based biofuels(2015)
; ;Kitzler, Hannes ;Beckmann, Georg; ;Pfeifer, Christoph260 1360 - PublicationDevelopment of a Ti-doped Sodium Alanate Hydrogen Storage System(2009)
; ;Reissner, Alexander ;Dudzinski, PiotrTajmar, MartinA trade-off analysis regarding power supply on satellites, which was performed for the European Space Agency (ESA), suggested that fuel cells might be an interesting candidate to replace secondary batteries on satellites. The Austrian Research Centers (ARC) decided to approach this topic by combining a fuel cell with innovative chemical hydrogen and oxygen storage as well as integrating the oxygen storage system into a form that can be used as a structural element. Also an integration of the fuel cell into the hydrogen tank, and the resulting storage of dissipation heat, results in a reduction of the necessary thermal control system. These advantages are very interesting in order to obtain higher weight efficiencies, which are especially important for space and automotive applications. The complete system includes a hydrogen storage tank based on Ti-doped sodium alanate and a novel oxygen tank based on YBaCo4O7 developed at ARC. Water tanks and a micro-fluidic system connected to the fuel cell have been considered as well in order to provide a completely reversible system, competitive to batteries. For the hydrogen storage, a finite elements model has been developed, implementing the reaction kinetics of the storage process, in order to predict the thermal mechanisms during adsorption and desorption of hydrogen in sodium alanate. The present paper discusses these simulations, the development of an experimental hydrogen storage tank and the proposed concepts of a battery replacement system.97 1 - PublicationDevelopment of a µ-scale Turbine Expander for Energy Recovery(American society of mechanical engineers, 2009)
; ;Dudzinski, Piotr ;Tajmar, Martin ;Willinger, ReinhardKäfer, KlausWaste heat is a primary source of energy loss in many applications. A number of developments around a micro rocket engine at the Austrian Research Centers (ARC) promise innovative energy recovery and micro power generation solutions. Here we focus on the investigation of micro technologies for application in HVAC (heating, ventilating, and air conditioning) systems. The use of μ-scale turbine expanders for work recovery in transcritical CO2 heat pump processes has been identified as most interesting and promising for the application in HVAC cases. One of the main drawbacks of transcritical CO2 heat pumps is the lower COP (coefficient of performance) compared to conventional heat pump systems which originates from the non isothermal heat rejection in the gas cooler. This drawback can be compensated by utilizing the pressure difference between the high pressure and low pressure part of the heat pump for work recovery. This is feasible as the pressure difference is considerably larger in case of CO2 heat pumps compared to conventional systems. Work recovery can be realized by substituting the expansion valve between the high and low pressure side by an expansion machine. Due to the low flow rate of the working fluid, the turbine type is based on the Pelton turbine with specific two phase flow turbine blades. In addition to the turbine part a magnetic coupling, miniature bearings and a small scale generator are important parts of the system. Thermodynamic simulations showed an absolute microturbine power yield between 60 W and 150 W for a 2 kW heating system.110 1 - PublicationDevelopment of Innovative Hydrogen and Micro Energy Solutions at the Austrian Research Centers(American Institute of Aeronautics and Astronautics, 2008-07-28)
; ;Tajmar, Martin ;Dudzinski, PiotrReissner, Alexander180 504Scopus© Citations 5 - PublicationDevelopment of Innovative Micro Power Converter Technologies at the Austrian Institute of Technology(American Institute of Aeronautics and Astronautics, 2009-08)
; ;Vasiljevich, Ivanhoe ;Dudzinski, Piotr ;Tajmar, MartinGerger, JoachimWaste heat is a primary source of energy loss in many aerospace and terrestrial applications. The Austrian Institute of Technology (AIT) is presently developing two different types of micro power converters, promising high efficiencies in their respective application areas. The first converter is based on an innovative thermoacoustic Stirling engine concept without moving parts. Such a maintenance-free engine system would be particularly suitable for advanced Stirling radioisotope space power systems. The second converter is based on microturbines to use exhaust-gases for improving the overall efficiency for a number of applications. This paper will summarize our efforts on micro power converter technologies.104 1Scopus© Citations 1 - PublicationENEREED - Sustainable Energy Conversion from Reed(Klima- und Energiefonds, 2013-12-19)
; ; ; ; ; ;Kitzler, Hannes ;Pfeifer, Christoph ;Hofbauer, HermannBeckmann, Georg258 4402 - Publication
255 1598 - PublicationGetting Fit for the Future: Optimizing Energy Usage in Existing Buildings by Adding Non-Invasive Sensor Networks(IEEE, 2018-08)
;Sauter, Thilo ;Treytl, Albert ;Diwold, Konrad ;Molnar, David ;Lechner, Daniel ;Krammer, Lukas; ; Optimizing energy usage is becoming an economic necessity for existing buildings. Non-invasive sensors and sensor networks are key technologies for efficiently achieving this goal, since it is of utmost importance that existing hydraulic systems are not changed and the engineering effort for installation remains minimal. This paper presents a data-driven approach that should allow low-cost installation of sensors at arbitrary points of the building and then retrieve the structure of the hydraulic system from the recorded sensor values. The architecture as well as first preliminary results from field test buildings are presented.403 1Scopus© Citations 1 - PublicationImproved µ-scale Turbine Expander for Energy Recovery(ASME, 2010-06-14)
; ;Dudzinski, Piotr ;Reissner, Alexander ;Hummel, StefanTajmar, Martin138 735Scopus© Citations 3 - PublicationInnovative Hydrogen Storage in Hollow Glass-Microspheres(2009)
; ;Schmid, G.Tajmar, Martin84 1 - Publication
132 206 - PublicationMeasurement data from real operation of a hybrid photovoltaic-thermal solar collectors, used for the development of a data-driven model(2023)
; ; ; This article presents a measurement dataset from real operation of a hybrid photovoltaic-thermal solar collector. The data is from a summer period, when the collector works at its higher temperature limit, with low thermal efficiency. The dataset characterizes the output of the collector: thermal (heat transfer fluid flowrate, inlet and outlet temperatures) and electrical (raw current and voltage, Hampel filtered power). Further information on the collector are the PV cell temperature and the back surface temperature (in three points). It provides detailed weather information: ambient temperature, solar resource (direct normal, global and diffuse horizontal, global tilted in the collector plane), equivalent radiative sky temperature (calculated from a pyrgeometer), wind speed and direction both horizontal and in the tilted collector plane. The calculated sun position with Duffie and Beckmann method is also given (elevation and azimuth) . The dataset covers 58 summer days from 11th July to 6th September, with a 5 second time step. The data is available as .mat file (MATLAB) and .csv file. A selection of variables from this dataset has already been used in the development of a data-driven model (see related article) [1]. The extended data presented in this article offers mode detailed weather information, opening further investigations opportunities. Further options for data-driven modelling of PVT collectors could be investigated. The correlation of wind related losses to horizontal wind measurements could be compared to a model with wind measurements in the collector plane. The dataset could support the validation of solar models, with direct and diffuse shares on the horizontal or in the tilted plane. [Duck Duck Go](https://duckduckgo.com)67 603 - PublicationMicro-Propulsion and Power Developments at AIT(2009-01-12)
; ;Tajmar, MartinScharlemann, CarstenThe increasing application of micro-satellites (from 10 kg up to 100 kg) as well as CubeSats for a rising number of various missions demands the development of miniaturized propulsion systems. The Austrian Institute of Technology is developing a number of micropropulsion technologies including both electric and chemical thrusters targeting high-performance at small scales. Our electric propulsion developments include FEEP thrusters with thrust ranges from μN to mN using highly-integrated clusters of indium Liquid-Metal-Ion Sources providing ultralow thrust noise and long-term stability, as well as the development of a micro PPT thruster enabling pointing capabilities for CubeSats. For chemical thrusters, we are developing novel micro-monopropellant thrusters with several hundred mN as well as a 1-3 N bi-propellant micro rocket engine using green propellants and high specific impulse performance. This paper will give an overview of our micropropulsion developments highlighting performance as well as possible applications.102 2 - Publication
73 1176 - PublicationMonitoring data from an office room in a real operating building, suitable for state-space energy modelling(2024)
; ; ; The dataset provides all necessary variables for data-driven energy modelling of an office room. The measurement data have been obtained from an office building operating as living lab in a temperate climate of Central Europe. The temperatures and the ventilation air flowrate are raw measurements, while the heat flows are calculated from measurements. The incoming solar irradiance is calculated with two façade models –simple and enhanced–, using measurements (solar irradiance, movable shading settings) and building characteristics (geometry, glazing and shading properties). One year and four months of data is provided with a fine one-minute time step and a coarser fifteen-minute time step. The dataset can be used to test and validate data-driven models, for example for predictive control applications.14 166 - PublicationNeutron transmission measurements on hydrogen filled microspheres(Elsevier, 2013-10-26)
;Dyrnjaja, Eva ;Hummel, Stefan; ;Smolle, Marie-Theres ;Gerger, JoachimZawiswky, MichaelHollow microspheres are promising candidates for future hydrogen storage technologies. Although the physical process for hydrogen diffusion through glass is well understood, measurements of static quantities (e.q. hydrogen pressure inside the spheres) as well as dynamic properties (e.g. diffusion rate of hydrogen through glass) are still difficult to handle due to the small size of the spheres (d ! 15 lm). For diffusion rate measurements, the long-term stability of the experiment is also mandatory due to the relatively slow diffusion rate. In this work, we present an accurate and long-term stable measurement technique for static and dynamic properties, using neutron radiography. Furthermore, possible applications for hydrogen filled microspheres within the scope of radiation issues are discussed.65 1Scopus© Citations 1