Das Projekt "Full-scale engineered barriers experiment in crystalline host rock" wird vom Umweltbundesamt gefördert und von Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH - Fachbereich Endlagersicherheitsforschung durchgeführt. General Information/Objectives: 1. Firstly to demonstrate the feasibility of handling and construction of the EBS components, including industrial manufacturing of highly compacted bentonite, quality assurance and system monitoring. It is also expected to gain experience and develop standards for the waste disposal techniques by the observation of the EBS during dismantling. 2. Secondly, the project seeks to study the thermo-hydro-mechanical processes in the near field, mainly in the buffer material as well as develop, verify and partially validate existing codes and constitutive relations. 3. Thirdly, the identification and modelling of alteration processes in the buffer including gas generation and transport, is also pursued. Proposal Content: The proposal complies with the CEU programme Workplan. The aim is to install in a 2.40 m diameter new drift at the Grimsel Test Site (Switzerland) two heaters 0.90 m in diameter and 4.54 m in length. The annular space between the heaters and the drift surface will he backfilled with highly compacted bentonite blocks. The drift will be sealed with a 5 meters long concrete plug. Temperature water content total pressure, pore pressure and displacements will be monitored by adequate sensors installed in the buffer and near field rock. The sealed part of the drift will be about 18.00 m long; 25 to 30 additional meters of drift will be required to install the on site control and monitory system. Another remote system will allow to control and monitor the experiment from Madrid (Spain) . Design, installation, heating, dismantling and integrated final analysis will take about 7 years. In the 3 years period covered by the CEU programme, design, installation partial heating and analysis will he achieved. Prior to the 'in situ' experiment, a mock-up test at almost 1:1 scale will be performed. Also two heaters, 0.30 m in diameter and 1.64 m in length, surrounded by bentonite blocks, will he confined within a metallic cylinder of 1.60 m diameter and 6.00 m long, with a hydration system. The sensors and monitory systems will he similar to those of the 'in situ' test. Laboratory test will be run for rock and buffer characterization for determination of the modelling parameters. 'Ad hoc' odometer and triaxial tests with controlled suction and temperature will also he performed in order to verity and partially validate codes and constitutive laws for unsaturated swelling clays. The existing codes and constitutive laws will be further developed during the testing period. In the body of the proposal the milestones and deliverables, partners of the project management structure and other items required are shown. Prime Contractor: Empresa Nacional de Residuos Radioactivos SA, Science and Technology Division; Madrid; Spain.
Das Projekt "Cloud-scale Uncertainties - B4: Radiative heating and cooling at cloud scale and its impact on dynamics" wird vom Umweltbundesamt gefördert und von Ludwig-Maxililians-Universität München, Meteorologisches Institut, Lehrstuhl für Experimentelle Meteorologie durchgeführt. Clouds are important sources and sinks of diabatic heat, not only in terms of latent heat release but also with respect to absorption of solar radiation as well as absorption and emission of thermal radiation. Additionally, cloud shadows on the ground modify surface heating and thus sensible and latent heat fluxes. Although it has been demonstrated that cloud top cooling may reach values of several 100 K/day and that this may have a strong impact on cloud microphysics and local cloud evolution, it has not been demonstrated that there is actually an effect on weather, larger scale dynamics, and on atmospheric flow. This is even more true for radiative cooling from cloud sides which has been shown to reach values comparable to cloud top cooling but is completely neglected by any (one-dimensional) radiation scheme in current NWP or climate models. Radiation firstly affects the growth of cloud droplets, increasing (in case of thermal cooling) or decreasing (in case of solar heating) the rate by which they dissipate the energy released by latent heat. Secondly, the surrounding air is cooled or heated which directly feeds back on dynamics. The aim of the project is to study the question if realistic, three-dimensional radiative heating rates have an impact on cloud formation, and if there is an impact on atmospheric flow beyond cloud scale. To answer these questions, a reasonably fast but accurate representation of radiative heating rates in clouds will be developed for a cloud scale (EULAG) and an NWP model (COSMO). The project builds upon our previous work on three-dimensional heating and cooling rates and on development of reasonably fast approximations. A parameterization of heating rates depends strongly on the scale. For a cloud-resolving model like EULAG with a 100 m grid size and smaller, different approaches are needed compared to a numerical weather forecast model like COSMO: A cloud-resolving model allows properly resolving the radiation processes, but three-dimensional radiation transport requires interaction between many grid columns in the calculation which is a challenge for parallelization. The resolution of COSMO, on the other hand, requires parameterization of un-resolved cloud edge effects and sub-pixel cloudiness, but would need less interaction between individual grid columns. As a first step, we will study the impact of radiative heating and cooling in clouds on local circulation at cloud scale. For that purpose, an accurate yet fast approximation for 3D solar and thermal heating and cooling rates will be developed for the EULAG model in order to systematically study effects for a set of cloud-resolving simulations. (abridged text)
Das Projekt "Design and planning of a demonstration power station with circulating pressurized fluidized bed firing" wird vom Umweltbundesamt gefördert und von Dawid-Saar durchgeführt. Objective: Design and construction of a coal fired power plant based on a combined cycle technology successfully applied to combustion of widely varying fuels for the purpose of steam generation and power production under environmentally acceptable conditions and net efficiency of more than 40 per cent for small plants (40 MWe) and a net efficiency of more than 45 per cent for large plants (smaller than 100 MWe). General Information: For clean gaseous and liquid fuels, combined cycle power plant engineering has in the meantime be accepted. This technology is less expensive and more efficient than that of conventional power plants. If coal is to be used in combined cycle power plant, efficient fuel gas and/or flue gas cleaning is an indispensable requirement. A direct and simple procedure to burn coal under pressure and than clean the flue gases at combustion temperature and combustion pressure with directly following expansion of the flew gas in a gas turbine with high thermal efficiency is the pressurized fluidized bed combustion of coal. Within the project the design of a bubbling pressurized fluidized bed combustor and the design of a circulating pressurized fluidized bed combustor was investigated as a basic for the realisation of a demonstration plant. In the bubbling pressurized fluidized bed combustor heat release and heat transfer are simultaneously taking place in the fluidized bed. This approach is attractive for it leads to very compact solutions. However, the complex requirements resulting from combustion, emission control, heat transfer, part load operation and dynamic process also entail some disadvantages. This comprises are not so notable in the circulating fluidized bed combustion due to separation of functions. In case of bubbling pressurized fluidized bed combustor, the entire combustion air flows through the fluidized bed. With due regard to possible erosion, the fluidizing velocity is limited to 1 m/sec, resulting in a relatively large cross section of the fluidized bed and a large pressure vessel diameter. In the circulating pressurized fluidized bed combustor, the combustion reactor does not contain any immersion-typ heating surfaces. Thus, the fluidizing velocities can be increased to up 5 m/sec which reduces the vessel diameter accordingly. The fluid bed heat exchanger for the circulating pressurized fluidized bed combustor can be conceived at discretion as regards its height/diameter ratio, owing to the small particle diameter of the circulating ash, the fluidizing velocity is here below 0.3 m/sec. Erosion problems are not anticipated in contrast to bubbling pressurized combustion systems. In bubbling pressurized fluidized bed combustion, the bed temperature is given for kinetic-reaction reasons. The transfer coefficient depends on the mean particle diameter and, as a result on the fuel preparation. Thus, dimensioning of the bed heating surface also depends on the fuel and its particle size ...
Das Projekt "Teilvorhaben: Erforschung und Entwicklung der PCM-Speicher und des Energie-Verteilsystems" wird vom Umweltbundesamt gefördert und von Innogration GmbH durchgeführt. Die Bundesregierung plant, bis zur Mitte des Jahrhunderts einen nahezu klimaneutralen Gebäudebestand zu erreichen. Neben dem effizienten Heizen eines Gebäudes wird das Kühlen immer wichtiger, sodass neue nachhaltige Lösungen gefordert sind. Im Rahmen des geplanten Projektes soll ein Wärmespeicher- und Energieerzeugungssystem für Gebäude erforscht und entwickelt werden, um die Gebäudebeheizung und -kühlung sicherzustellen, Überhitzungen zu vermeiden und überschüssige Wärmeenergie im tages- und jahreszeitlichen Zyklus zu speichern bzw. verfügbar zu machen. In Verbindung mit Flächenheizungen und Bauteilaktivierungen lässt sich so eine klimaneutrale Energieversorgung des Heiz-/Kühlsystems bei gleichzeitig hohem thermischen Komfort der Gebäude erreichen. Die Innovation des angestrebten Ziels besteht darin, dass die Energieerzeugung in autarken 'Energiepfählen' stattfindet, sodass im Gebäude selber eine aufwändige Haustechnik vermieden werden kann. Die Besonderheit besteht ferner darin, dass zur Energiespeicherung Speichersysteme auf verschiedenen Temperaturniveaus verwendet werden. Dies soll durch die Anwendung von PCM-Material und Peltier-Elementen ermöglicht werden. Über eine intelligente Steuer- und Regeltechnik soll die Wärmeenergie optimal eingesetzt oder gespeichert werden, sodass über den kompletten Jahresverlauf hinweg möglichst wenig Energie von Netzanbietern benötigt wird.
Das Projekt "Messung der Einspeicherung und des Verbrauchs von solarer Waermeenergie" wird vom Umweltbundesamt gefördert und von Fachhochschule für Technik Esslingen, Fachbereich Versorgungstechnik durchgeführt. Eine bestehende Warmwasser-Zentralheizung mit Brauchwassererwaermung, bei der Radiatoren-, Fussboden- und Deckenheizung kombiniert sind, ist durch eine Solaranlage erweitert worden, die in erster Linie den Waermebedarf eines neuerbauten Schwimmbades deckt. Ziel der Untersuchung ist die Messung der zugestrahlten Solarenergie, sowie die Verteilung auf die verschiedenen Verbraucher.
Das Projekt "Waermepumpen mit Absorber-Waermetauschern" wird vom Umweltbundesamt gefördert und von Energietechnik GmbH Studiengesellschaft für Energie-Umwandlung, -Fortleitung und -Anwendung durchgeführt. Objective: The demonstration of novel absorber type heat exchanger using environmental heat in combination with electric heat pumps for room heating purposes. General Information: One 8 dwellings multifamily building is equipped with an energy stack of 220 m2 absorber surface and a brine-water heat pump with a capacity of 48.5 kwth. Also one single family house is equipped with an energy fence of 43,2 m2. absorber surface and a brine water heat pump with a capacity of 11 KW/th. The heat pumps are of the bivalent type. When outside air temperatures are below 3 C the existing oil fired boilers are used. The energy stack is installed on the roof of the building and consists of 40 horizontally arranged heat exchanger plates of anodised aluminium (in two units) with an integrated brine duct system. The energy fence deliminates the garden behind the house southwards and consists of bent U-shaped, plastic coated aluminium sheets with an extruded section is glued to their central portion as a brine duct. Achievements: The heating system was monitored for two seasons: September 1982 to May 1983 ; September to May 1984, during which heat pump output and it's COP of 2.3 failed to meet manufacturer's projections. This is attributed to the fact that the evaporator heat exchanger surfaces were poorly adapted to the condensor, a mis-match causing high temperature differentials between the brine and evaporation temperature, and the condensation and heating water temperature. A better matching of the heat exchangers may increase COP by as much as one point. The energy stack operated satisfactorily, in accordance with the manufacturers specifications, and was found to the be the most durable component of the heat pump system. Energy savings for the demonstration period are equivalent to 7.2 TOE. The planned construction of a second multifamily unit, to be supported by the heat pump will increase annual power consumption from 27,000 kWh to 41,000 kWh and, in combination with tax benefits in Germany, will reduce the payback period to 4.5 years. Single Family Building. The heating system operated from October 1982 to April 1983 and from October 1983 to May 1984. Throughout the demonstration, the heat pump supplied the heating requirements for all the houses (except for a few instances of minor problems with the pump e.g. leakage in the refrigerator circuit). One of the two heat pumps was particularly problematic and had to be replaced. The other operated very well, reaching a COP of 2.8 during the second season. The energy fence was problem-free and easily met the manufacturer's output projections. Operating costs for heating the house were reduced by almost 50 per cent, dropping from DM 3,760 to DM 2,020. Annual fuel oil substitution was equivalent to 1.74 TOE for an electricity consumption of 6,900 kWh. The average COP per heating period was 2.2.
NiOx films grown from 50 nm thick Ni on Si(111) were put in contact with oxygen and subsequently water vapor at elevated temperatures. Near ambient pressure (NAP)-XPS and -XAS reveal the formation of oxygen vacancies at elevated temperatures, followed by H2O dissociation and saturation of the oxygen vacancies with chemisorbing OH. Through repeated heating and cooling, OH-saturated oxygen vacancies act as precursors for the formation of thermally stable NiOOH on the sample surface. This is accompanied by a significant restructuring of the surface which increases the probability of NiOOH formation. Exposure of a thin NiOx film to H2O can lead to a partial reduction of NiOx to metallic Ni accompanied by a distinct shift of the NiOx spectra with respect to the Fermi edge. DFT calculations show that the formation of oxygen vacancies and subsequently Ni0 leads to a state within the band gap of NiO which pins the Fermi edge. © the Owner Societies 2023
Das Projekt "Teilvorhaben: Entwicklung der Steuer- und Regelungstechnik" wird vom Umweltbundesamt gefördert und von CuroCon GmbH durchgeführt. Die Bundesregierung plant, bis zur Mitte des Jahrhunderts einen nahezu klimaneutralen Gebäudebestand zu erreichen. Neben dem effizienten Heizen eines Gebäudes wird das Kühlen immer wichtiger, sodass neue nachhaltige Lösungen gefordert sind. Im Rahmen des geplanten Projektes soll ein Wärmespeicher- und Energieerzeugungssystem für Gebäude erforscht und entwickelt werden, um die Gebäudebeheizung und -kühlung sicherzustellen, Überhitzungen zu vermeiden und überschüssige Wärmeenergie im tages- und jahreszeitlichen Zyklus zu speichern bzw. verfügbar zu machen. In Verbindung mit Flächenheizungen und Bauteilaktivierungen lässt sich so eine klimaneutrale Energieversorgung des Heiz-/Kühlsystems bei gleichzeitig hohem thermischen Komfort der Gebäude erreichen. Die Innovation des angestrebten Ziels besteht darin, dass die Energieerzeugung in autarken 'Energiepfählen' stattfindet, sodass im Gebäude selber eine aufwändige Haustechnik vermieden werden kann. Die Besonderheit besteht ferner darin, dass zur Energiespeicherung Speichersysteme auf verschiedenen Temperaturniveaus verwendet werden. Dies soll durch die Anwendung von PCM-Material und Peltier-Elementen ermöglicht werden. Über eine intelligente Steuer- und Regeltechnik soll die Wärmeenergie optimal eingesetzt oder gespeichert werden, sodass über den kompletten Jahresverlauf hinweg möglichst wenig Energie von Netzanbietern benötigt wird.
Das Projekt "Modifizierte Onsite Aluminierung von Stählen mit Randschichtglühmethoden und einem chromat- und halogenaktivatorfreien Slurry" wird vom Umweltbundesamt gefördert und von DECHEMA Forschungsinstitut Stiftung bürgerlichen Rechts durchgeführt. The aluminization by means of commercial slurries is a coating method in which the aluminium (Al) diffusion coating is developed at the substrate surface by covering it with Al slurry, followed by a heat treatment. The disadvantages of this method are that the slurry usually includes toxic chromates and phosphates, that the heat treatment process has to be carried out in an inert atmosphere for several hours, which can be a logistical challenge, and furthermore the material microstructure can be affected adversely. The goal of this project is to develop a coating process by combining a non-toxic water-based slurry with a surface heat treatment, which can be performed by induction heating, burner flame, or heating mat for several minutes at ambient atmosphere. This includes several advantages such as health and environmental compatibility, cost saving, and easier material maintenance. Experiments on specimens of iron- and nickel-based alloys have shown that closed coatings can be developed by this method. However, they consist of intermetallic phases with a high aluminium concentration. The goal of this project is to optimize the coatings by promoting the development of the beta-FeAl and NiAl intermetallic phases and by adding other elements (e.g. Cr, Si, etc.) to the Al coating.
Das Projekt "Teilvorhaben: Wärme- und strömungstechnische Analyse eines ZMW-Rohr-Verbundsystems" wird vom Umweltbundesamt gefördert und von Fraunhofer-Institut für Fertigungstechnik und Angewandte Materialforschung, Institutsteil Dresden durchgeführt. In vielen Bereichen der Gebäudeenergietechnik, ist der Trend zur Kombination von Komponenten zu erkennen. Diese Hybridisierung soll auf Flächenheiz- und -kühlsysteme ausgeweitet werden indem Funktionen der Flächenheizung/-kühlung und Raumluftkonditionierung kombiniert werden. Ziel ist es, durch Verwendung innovativer, zellularer, metallischer Werkstoffe (ZMW, Metallschaum, metallische Faserstrukturen), die thermischen Eigenschaften, wie z.B. die Temperaturwelligkeit an der Oberfläche, deutlich zu verbessern. Dadurch kann die notwendige Übertemperatur des Heizmediums reduziert und Energie eingespart werden. Die wichtigsten Vorhabenziele sind die Auswahl, Konzeption und Entwicklung notwendiger Technologien zum Aufbau hybrider, modularer Flächenelemente. Das Teilprojekt am Fraunhofer IFAM Dresden (IFAM-DD) befasst sich mit der wärme- und strömungstechnischen Auslegung und Charakterisierung der betrachteten ZMW. Das beinhaltet die Herstellung metallischer Faserstrukturen sowie die Untersuchung und thermische Bewertung des Rohr-ZMW-Verbunds.