Seithel R.,Karlsruhe Institute of Technology |
Steiner U.,ERDWERK GmbH |
Muller B.,Karlsruhe Institute of Technology |
Hecht C.,Stadtwerke Munich |
Kohl T.,Karlsruhe Institute of Technology
Geothermal Energy | Year: 2015
Background: The characterization of fault zones in the Bavarian Molasse Basin plays a major role for further geothermal reservoir development. Hence, their identification, geological origin, and hydraulic characterization are discussed extensively. Methods: Stress indicators and fractures are interpreted from image and caliper logs of three highly deviated wells at the Sauerlach site. We transform the identified stress field into the borehole coordinate system and compare the observed orientation to the modeled stress field which assumes a homogeneous borehole surrounding. Results: High breakout occurrence, cross-cutting fractures, and a fracture orientation from N-S to NNE-SSW are observed in Sauerlach Th1. In Sauerlach Th2 and Th3, fractures strike primarily ENE-WSW and N-S to NNE-SSW. Drilling-enhanced natural fractures and drilling-induced tensile fractures are observed in all three wells and indicate the orientation of tensile stress at the borehole wall. In Sauerlach Th2 and Th3, stress transformation indicates a SH-dir. ~ N 10°E in a strike-slip stress regime. The modeled stress orientations match the observed orientations within the well Sauerlach Th1 if either SH-dir. is N 320°E in a strike-slip regime or SH-dir. is N 10°E in a normal faulting regime. Conclusion: This approach improves the detection of the local stress field especially for non-vertical wells, which has, in combination with the facture pattern, a major impact on the hydraulic system of the geothermal reservoir. © 2015, Seithel et al.; licensee Springer.
Schacht A.,RWTH Aachen |
Munk M.,Stadtwerke Munich |
Busen C.,RWTH Aachen |
Oeser M.,RWTH Aachen
Bautechnik | Year: 2014
The transportation of goods on roads represents by far the biggest part of the traffic capacity; as a result, this must always be maintained through appropriate procedures, also under unfavourable weather conditions in the winter season. One possible way is the temperature control of the surface with a kind of liquid. With this method, the decisive accident causes in winter, such as slipperiness through rain, snow and ice, which result in great economic damage through hindering the transport, can be counteracted. The conception of temperature control on asphalt road is not brand-new. At the moment, the temperature control is typically achieved by installing tubes assembly, in which a kind of liquid flows. However, the tube system has disadvantages in fabrication and the economical provision. Therefore in this research the concept of porous asphalt interlayer was considered, which is similar to the above method flow through with a liquid. Apart from the porous asphalt interlayer, further applications with polyurethane binding interlayer were investigated. Objects of the investigation were the construction practicability of this porous interlayer and the aspects of durability, deformation behavior, water permeability and the thermal effectiveness of this concept. © 2014 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.
Muhle F.,TU Munich |
Rapp C.,Stadtwerke Munich |
Mayer O.,General Electric
WasserWirtschaft | Year: 2013
As great hydro power potentials are already exploited in Germany the main focus Is on local small scale hydro power. Various concepts for such plants exist; among these Is the water vortex power plant which Is subject to this work. Designs for the vortex chamber, the turbine or the Inlet and outlet configuration are barely available. A design model was developed and according to this a physical model has been set up at scale 1:9. Different quantities were varied to Identify determining parameters. Velocities were measured In the vortex chamber and the performance of the power plant was evaluated. The outlet opening has the greatest Influence on the velocity distribution In the vortex chamber and on the turbine efficiency coefficient (greatest = best) which was approx. 0.5. The efficiency Is strongly depending on the flow depth In the inlet channel. The power plant with an overall efficiency of approx. 31 % is suited for small potential energy heads.
Gunther M.,Stadtwerke Munich |
Greller M.,Stadtwerke Munich |
Fallahnejad M.,Stadtwerke Munich
Informatik-Spektrum | Year: 2015
Stadtwerke München operates a power plant fleet for covering the demand in district heating grids of Munich. Both district heating grids and the power plant fleet will be facing major changes in coming years. In order to assess the impacts of these changes in technical and economic terms, a software solution has been developed at Stadtwerke München containing a long-term unit commitment optimization tool as well as a superior model for scenario building and profit analysis. An in-depth overview of this software solution is presented in this paper. © 2014, Springer-Verlag Berlin Heidelberg.
Gunther M.,Stadtwerke Munich
WasserWirtschaft | Year: 2014
The economy of two pump storage stations at the spot market will be evaluated in this paper. Therefore, a deterministic and a stochastic model were developed. Both models use a fundamental hourly price forward curve, which is based on a fundamental long term model of the European generation system. As a result it will be shown that none of the two pump storage stations are economical, if a fair return is required. Thus, conditions are explained which are important for an economical investment into pump storage stations.