Energie und Mobilität
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Im Zuge der Energiewende werden die erneuerbaren Energien zur tragenden Säule unserer Stromversorgung. Bis 2025 sollen bundesweit 40-45 % des Stroms aus erneuerbaren Quellen stammen, bis 2050 sogar 80 %. Dabei wird der erzeugte Strom hauptsächlich aus Wind und Sonne stammen. Im Norden der Bundesrepublik wird Wind die Erzeugung dominieren, während im Süden, insbesondere in Bayern der Strom vornehmlich aus Photovoltaik gewonnen werden wird. Um die Ziele der Energiewende zu erreichen, wird neben den ausreichenden Erzeugungskapazitäten auch eine leistungsfähige Infrastruktur zur Verteilung und Nutzung des erneuerbaren Stroms notwendig sein. Planbarkeit und Sicherung der Versorgungsqualität bei zunehmenden Anteilen von volatiler Erzeugung werden dabei zu einer immer größeren Herausforderung. Das Projekt neos hat im engen Verbund mit den beteiligten Partnern wichtige tagesaktuelle Fragestellungen wissenschaftlich erörtert und untersucht, die sich durch die laufende Transformation des Energiesystems und den rasanten Ausbau der Anlagen zur erneuerbaren Energieerzeugung den Projektpartnern stellen.
Das vom BMWi geförderte Forschungsprojekt SyNErgie (03/2015 bis 05/2018) beschäftigt sich mit der Weiterentwicklung von Netzplanungsprozessen [1]. Im Fokus steht dabei die Modellierung von Blindleistungsflüssen und die dezentrale Nutzung von Blindleistungsquellen (z. B. Wechselrichter, Ladedrosseln, Kondensatoren) in Mittelspannungsnetzen, über welche der Blindleistungshaushalt letztendlich beeinflusst werden soll. Im Rahmen dieses Beitrags wird anhand eines realen Mittelspannungsnetzes (MS-Netz) gezeigt, welche Modellierungsschritte zur Erstellung eines möglichst realitätsnahen Simulationsabbilds nötig sind. Dies ist notwendig, um der Verteilnetzplanung eine robuste Planungsgrundlage für die Ableitung von Entscheidungen im Rahmen eines Blindleistungsmanagements zur Verfügung zu stellen.
Das vom BMWi geförderte Forschungsprojekt SyNErgie (03/2015 bis 05/2018) beschäftigt sich mit der Weiterentwicklung von Netzplanungsprozessen [1]. Im Fokus steht dabei die Modellierung von Blindleistungsflüssen und die dezentrale Nutzung von Blindleistungsquellen (z. B. Wechselrichter, Ladedrosseln, Kondensatoren) in Mittelspannungsnetzen, über welche der Blindleistungshaushalt letztendlich beeinflusst werden soll. Diese Veröffentlichung konzentriert sich auf die konzipierte Erweiterung des Netzplanungsprozesses zur Einbindung von Blindleistungsquellen im Verteilungsnetz in ein Blindleistungsmanagement. Deren einzelne Phasen werden erläutert und anschließend die Netz-Sensitivitäts- und -Restriktionsanalyse anhand eines realen Mittelspannungsnetzes demonstriert. Abschließend werden mögliche Abschwächungs- und Verstärkungseffekte im Hinblick auf einen Blindleistungsabruf über mehrere Spannungsebenen hinweg diskutiert.
Monitoring of structures and related decisions based on cost optimization are discussed in this contribution. Many research publications and experimental data are currently available on inspection and on monitoring and they represent the outcome of the remarkable work done. Not all the topics of interest are widely debated and implemented in standards. The current state-of-practice in standards is summarized and aspects to be included in future recommendations are proposed. The implementation of risk-based decisions is illustrated in a case study dealing with a stadium roof in Northern Italy. Snow actions are important especially in northern and mountainous regions where heavy snowfalls and related accumulation result to considerable loads. As the roof structure fails to comply with the requirements of Eurocodes, a permanent monitoring system has been installed to allow for real time evaluation of the reliability level of the structure. The system supplies the necessary information supporting immediate decisions on closure of the stadium in case of an extraordinary snow load. Cost-optimal decisions regarding the closure of the stadium are analysed based on a limit state function, on probabilistic models for the influencing parameters including measurement uncertainty, economic losses related to closure and failure consequences. The results demonstrate the potential of the use of the monitoring systems and probabilistic reliability analysis in order to support decisions and highlight the need for their implementation in future standards.
This paper deals with the locomotion by tilting sequences of shape-variable compliant tensegrity structures. The shape of these structures is controlled by manipulating their prestress state. The tensegrity structure is tilting as consequence of a suitable variation of its shape. By multiple repetition of such tilting sequences a motion is generated. Quasi-static considerations for the considered structures are presented in order to estimate the actuation parameters. For a proper number of actuators this quasi-static approach enables an analytical calculation of the actuation parameters of the structure in order to control the geometrical configuration as required. As an example a two-dimensional tensegrity structure which is in contact with a horizontal plane due to gravity is considered. By successive tilting sequences a uniaxial motion results. The excitation of the structure is calculated for a given change of shape with the quasi-static analysis. The according results are compared with transient dynamic simulations. Qualitative conclusions about the motion behavior and the usability of the quasi-static approach are given.
Mobile cranes are regularly operated in regions which experience ultra deep operating temperatures of down to -60?C (-76?F). In safety regulated work environments crane operations will be suspended simply because the lowest wire rope working temperature stated in the applicable standards is -40?C/F. Examples of ultra deep temperature wire rope application are shown in Figure 1.1 and 1.3. It should be noted that this paper is written in conjunction with a paper written by the co-author Ulrich Briem titled “Fatigue Behaviour of Rope Wires”, presented and published in unison with this one. In order to analyze the behaviour under ultra deep temperature conditions, tests on wire rope as well as on rope wires were carried out. In the following, static tensile and bending test results with rope and rope wires will be reported, which were carried out in conditions of down to -95?C (-139?F) as well as at room temperature. The conclusion is that the results of these tests can be adopted to crane wire rope as well.
The rope curve line of a tensioned rope can be described by means of the catenary curve. Opposed to that, the curved line of a free bent rope cannot be described by an analytical function. Practical applications of free bending are for example at tail ropes at the bottom of shaft in rope drives with traction sheaves. The question whether the maximum diameter of rope loop is small enough for the diameter of the shaft is highly interesting. In [1] a method was presented to calculate the curved line of free bent ropes numerically by help of energy methods. An analytical description of rope curve line would be very helpful. Beginning with the structure of a rope curve line of tensioned rope (catenary curve) and considering the influence of bending stiffness, the structure of an analytical equation for the curve line of a free bent rope will be developed. The main focus of this paper is to develop and to describe the structure of such an analytical equation. To get a first idea about the values of the constants in that analytical equation a few test results were evaluated. But these equations consider the static rope behavior only. Due to dynamic effects in the rope while running through the loop at the bottom of a shaft, pendulousness of the tail rope occurs.
The rope curve line of a tensioned rope can be described by means of the catenary curve. Opposed to that, the curved line of a free bent rope cannot be described by an analytical function. Practical applications of free bending are for example at tail ropes at the bottom of shaft in rope drives with traction sheaves. The question whether the maximum diameter of rope loop is small enough for the diameter of the shaft is highly interesting. In [1] a method was presented to calculate the curved line of free bent ropes numerically by help of energy methods. An analytical description of rope curve line would be very helpful. Beginning with the structure of a rope curve line of tensioned rope (catenary curve) and considering the influence of bending stiffness, the structure of an analytical equation for the curve line of a free bent rope will be developed. The main focus of this paper is to develop and to describe the structure of such an analytical equation. To get a first idea about the values of the constants in that analytical equation a few test results were evaluated. But these equations consider the static rope behavior only. Due to dynamic effects in the rope while running through the loop at the bottom of a shaft, pendulousness of the tail rope occurs.
Water vapor adsorption kinetics on small and full scale zeolite coated adsorbers; A comparison
(2013)
A possibility to enhance both heat and mass transfer characteristics of an adsorber heat exchanger is to apply the adsorbent directly to its surface in form of a consolidated layer. As the majority of the available publications on the effect of both coating technology and adsorbent layer thickness on the adsorption kinetics deals with small scale adsorbent samples, the results obtained can only represent the best case design of an adsorber heat exchanger. This article presents, therefore, a comparison between the adsorption kinetics of water vapour on small as well as two different full scale coated adsorber heat exchanger types with AQSOA-Z02 layers of Mitsubishi Plastics Incorporation under quasi isobaric conditions of adsorption heat pumps. The small scale coated samples have a zeolite dry mass of 200 mg and layer thicknesses of 200, 300 and 500 μm while the full scale adsorbers have a coated zeolite mass between 1.5 and 2.5 kg and layer thicknesses of 150, 200, 300, 400 and 500 μm. In the investigated adsorption heat pump module, up to 52.7 and 57.3% of the equilibrium differential water loading measured with the small scale coated substrates have been obtained after an adsorption-evaporation times of 300 and 600 s, respectively.
Im Kontext der Energiewende sind Energiespeicher ein zentrales technisches, wirtschaftliches und energiepolitisches Thema.Die Autoren dieses kompakten Werkes geben einen umfassenden Uberblick Uber die verschiedenen Aspekte der Energiespeicherung. Sie beschreiben zunachst die Bedeutung von Energiespeichern in der Energieversorgung und definieren ihre Rolle darin. Dann gehen sie auf den Speicherbedarf in der Strom-, Warme- und Kraftstoffversorgung im Kontext der Energiewende ein. Im Hauptteil werden die verschiedenen Speichertechnologien ausfUhrlich vorgestellt sowie ihre Vor- und Nachteile diskutiert. Praktische Anwendungsbeispiele und die Integration von Speichern Uber alle Energiesektoren hinweg runden das Buch ab. Zahlreiche Grafiken und Beispiele veranschaulichen das gesamte Feld der Energiespeicher und sind als Erganzung samt Animationen online in Farbe verfUgbar.Die ZielgruppenDas Lehr- und Fachbuch wendet sich an Ingenieure, Wissenschaftler, Energieplaner und Energiewirtschaftler in Forschung und Industrie sowie an Studierende an Hochschulen und Universitaten in den Bereichen Maschinenbau, Verfahrenstechnik, Elektrotechnik und Energietechnik.
Die Autoren dieses Werkes geben einen umfassenden Überblick über die verschiedenen Aspekte der Energiespeicherung. Sie beschreiben zunächst die Bedeutung von Energiespeichern in der Energieversorgung und definieren ihre Rolle darin. Dann gehen sie auf den Speicherbedarf in der Strom-, Wärme- und Kraftstoffversorgung im Kontext der Energiewende ein. Im Hauptteil werden die verschiedenen Speichertechnologien ausführlich vorgestellt sowie ihre Vor- und Nachteile diskutiert. Praktische Anwendungsbeispiele und die Integration von Speichern über alle Energiesektoren hinweg runden das Buch ab. Zahlreiche Grafiken und Beispiele veranschaulichen das gesamte Feld der Energiespeicher und sind als Ergänzung mehrsprachig online in Farbe verfügbar.
Die 2. Auflage enthält ein neues Kapitel zu den rechtlichen Rahmenbedingungen, neue Studien zum Speicherbedarf, Power-to-X für die chemische Industrie, neue LOHC- und Lageenergiespeicher sowie neueste Trends zu Kostenentwicklung und Batterieanwendungen.
„Endlich ein umfassendes Buch zur Energiewende, das auch für technische Laien verständlich und inspirierend geschrieben ist." Franz Alt, Journalist und Buchautor
„Das großartige Werk sei allen empfohlen, die sich wirklich für die Zukunft unseres Landes interessieren. Es zeigt auf eindrucksvolle Weise: Es wird nicht einfach, aber wir schaffen das.“ Prof. Dr. Harald Lesch, Physiker und Fernsehmoderator
In this paper, a new method for a minimum-error pose estimation of cylinder axes based on apparent contour line features from multiple views is presented. Novel model equations for both single and particularly multiple views are derived, and based upon these, an algorithm for least squares fitting the model to imaged cylinder contour line features is introduced. The good performance of the proposed algorithm is shown by solving an exemplary fitting problem.
The present paper deals with the experimental validation of tyre dynamics approaches as it is widely applied in tyre models for vehicle dynamics and handling. Firstly it gives a brief derivation of two modelling principles regarding the deflection velocity in the considered direction of the tyre’s deformation. This is than followed by a brief description of the performed measurement procedure. From the measurements, a set of model parameters of the considered tyre, depending on different manoeuvre speeds and frequencies, is identified, where no particular fitting parameters for the tyre dynamics are needed. Based on these model parameters, the related dynamic simulations are carried out. The comparisons show that the applied first-order model describes the behaviour quite well within a certain operation range, whereas the second-order approach cannot deliver better results in spite of the longer computational time. However, for investigations within an enlarged frequency range of the steer input and at high slip angles, a more detailed model is recommended.
Power-to-Gas
(2016)
This chapter provides an overview on the storage technology power-to-gas for the decarbonization of all energy sectors. Other than “negative emissions” with CCS or biomass, which have clear limits in potentials, costs and environmental benefits, storage and energy conversion technologies like power-to-gas and power-to-x enable the decarbonization by neutralizing the CO2 footprint of all energy services. Via the conversion of renewable electricity into chemical energy carriers like renewable hydrogen or renewable hydrocarbons, the existing fossil infrastructure with vast and sufficient storage and transport capacities can be used with carbon neutral renewable energy. After showing the demand for storage technologies, the technology components of power-to-gas are described, building the basis for the storage system power-to-gas itself that is described in detail, including efficiency, potential, CO2 emissions, and costs. In conclusion, a technical pathway of decarbonization including costs is described for the industrial nation of Germany and necessary policy frameworks are derived.
Dieses Lehrbuch stellt die Methoden der Mehrkörpersimulation anschaulich dar und erläutert an einfachen Beispielen die Vor- und Nachteile bei der praktischen Anwendung. In den Text integrierte Matlab-Skripte und -Funktionen verdeutlichen die einzelnen Methoden. Die Modellbildung, die mathematische Beschreibung und die numerische Simulation von Systemen starrer Körper bilden dabei die Schwerpunkte. Konkrete Beispiele beinhalten die Eigendynamik eines Traktors mit Vorderachsfederung, das Hubschrauberrotorblatt sowie eine Pkw- Vorderachse. Die entsprechenden Matlab-Skripte und Lösungen zu den Übungsaufgaben können auf der Springer-Homepage beim Buch heruntergeladen werden. Neu aufgenommen wurden SparseMatrix Operationen sowie ein Beispiel zu einfach geschlossenen kinematischen Schleifen.
Exchange conditions at the forest floor are complex due to the heterogeneity of sources and sinks and the inhomogeneous radiation but are important for linking soil respiration to measurements in the trunk space or above canopy. Far more attention has therefore been paid to above and within canopy flows, but even studies that addressed forest floor exchange do not present measurements below 1 m or 2 m. We used a multilayer model that explicitly resolves the laminar layer, the buffer layer, and the turbulent layer to calculate fluxes from the measured profiles in the lowest meter above ground and to calculate effective surface concentrations from given fluxes. The calculated fluxes were compared to measured eddy covariance fluxes of sensible heat and O3 and to chamber derived soil fluxes of CO2 and 222Rn. Sensible heat fluxes agreed surprisingly well given the heterogeneity of radiative heating and the generally low fluxes (max. 25 W m−2). The chamber fluxes turned out to be not comparable as the chamber fluxes were too low, probably due to one of the well-known problems of enclosures such as pressure differences, disturbed gradients and exclusion of naturally occurring turbulence events and surface cooling. The O3 fluxes agreed well for high O3 values reaching down to the forest floor during full coupling of the canopy by coherent structures. During most of the time, the model overestimated the fluxes as chemical reactions were dominating within the profile. One new approach was to calculate the effective surface concentration from a given flux and compare this to measured surface concentrations. This allowed the identification of situations with a coupled and decoupled forest floor layer, which has important consequences for respiration measurements in the trunk space or above canopy and should be considered in upcoming studies.
Power-to-Gas
(2017)
This chapter provides an overview on the storage technology power-to-gas for the decarbonization of all energy sectors. Other than “negative emissions” with CCS or biomass, which have clear limits in potentials, costs and environmental benefits, storage and energy conversion technologies like power-to-gas and power-to-x enable the decarbonization by neutralizing the CO2 footprint of all energy services. Via the conversion of renewable electricity into chemical energy carriers like renewable hydrogen or renewable hydrocarbons, the existing fossil infrastructure with vast and sufficient storage and transport capacities can be used with carbon neutral renewable energy. After showing the demand for storage technologies, the technology components of power-to-gas are described, building the basis for the storage system power-to-gas itself that is described in detail, including efficiency, potential, CO2 emissions, and costs. In conclusion, a technical pathway of decarbonization including costs is described for the industrial nation of Germany and necessary policy frameworks are derived.