@article{MottaghyPechnigVogt2011, author = {Mottaghy, Darius and Pechnig, Renate and Vogt, Christian}, title = {The geothermal project Den Haag: 3D numerical models for temperature prediction and reservoir simulation}, series = {Geothermics}, volume = {40}, journal = {Geothermics}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0375-6505}, doi = {10.1016/j.geothermics.2011.07.001}, pages = {199 -- 210}, year = {2011}, abstract = {The proposed Den Haag Zuidwest district heating system of the city of The Hague consists of a deep doublet in a Jurassic sandstone layer that is designed for a production temperature of 75 °C and a reinjection temperature of 40 °C at a flow rate of 150 m3 h-1. The prediction of reservoir temperature and production behavior is crucial for success of the proposed geothermal doublet. This work presents the results of a study of the important geothermal and geohydrological issues for the doublet design. In the first phase of the study, the influences of the three-dimensional (3D) structures of anticlines and synclines on the temperature field were examined. A comprehensive petrophysical investigation was performed to build a large scale 3D-model of the reservoir. Several bottomhole temperatures (BHTs), as well as petrophysical logs were used to calibrate the model using thermal conductivity measurements on 50 samples from boreholes in different lithological units in the study area. Profiles and cross sections extracted from the calculated temperature field were used to study the temperature in the surrounding areas of the planned doublet. In the second phase of the project, a detailed 3D numerical reservoir model was set up, with the aim of predicting the evolution of the producer and injector temperatures, and the extent of the cooled area around the injector. The temperature model from the first phase provided the boundary conditions for the reservoir model. Hydraulic parameters for the target horizons, such as porosity and permeability, were taken from data available from the nearby exploration wells. The simulation results are encouraging as no significant thermal breakthrough is predicted. For the originally planned location of the producer, the extracted water temperature is predicted to be around 79 °C, with an almost negligible cooling in the first 50 years of production. When the producer is located shallower parts of the reservoir, the yield water temperatures is lower, starting at ≈76 °C and decreasing to ≈74 °C after 50 years of operation. This comparatively larger decrease in temperature with time is caused by the structural feature of the reservoir, namely a higher dip causes the cooler water to easily move downward. In view of the poor reservoir data, the reservoir simulation model is constructed to allow iterative updates using data assimilation during planned drilling, testing, and production phases. Measurements during an 8 h pumping test carried out in late 2010 suggest that a flow rate of 150 m3 h-1 is achievable. Fluid temperatures of 76.5 °C were measured, which is very close to the predicted value.}, language = {en} } @article{BergAngererMartinellietal.2013, author = {Berg, Milena and Angerer, Anita and Martinelli, Walter and Hammer, Stephan and Mottaghy, Darius}, title = {Erkundung des geothermischen Potenzials eines ehemaligen Untertagebergbaus}, series = {BBR - Fachmagazin f{\"u}r Brunnen- und Leitungsbau}, volume = {64}, journal = {BBR - Fachmagazin f{\"u}r Brunnen- und Leitungsbau}, number = {6}, pages = {46 -- 52}, year = {2013}, language = {de} } @article{MottaghyPechnigTaugsetal.2010, author = {Mottaghy, Darius and Pechnig, Renate and Taugs, Renate and Kr{\"o}ger, Jens and Thomsen, Claudia and Hesse, Fabian and Liebsch-Doerschner, Thomas}, title = {Erstellung eines geothermischen Modells f{\"u}r Teile Hamburgs und anliegende Gebiete}, series = {BBR - Fachmagazin f{\"u}r Brunnen- und Leitungsbau}, volume = {61}, journal = {BBR - Fachmagazin f{\"u}r Brunnen- und Leitungsbau}, number = {12}, publisher = {WVGW Wirtschafts- u. Verl.Ges. Gas und Wasser}, address = {Bonn}, issn = {1611-1478}, pages = {52 -- 59}, year = {2010}, language = {de} } @article{MottaghyPechnig2009, author = {Mottaghy, Darius and Pechnig, Renate}, title = {Numerische 3D Modelle zur Temperaturvorhersage und Reservoirsimulationen}, series = {BBR - Fachmagazin f{\"u}r Brunnen- und Leitungsbau}, volume = {60}, journal = {BBR - Fachmagazin f{\"u}r Brunnen- und Leitungsbau}, number = {10}, pages = {44 -- 51}, year = {2009}, language = {de} } @article{MottaghyVosteenSchellschmidt2008, author = {Mottaghy, Darius and Vosteen, Hans-Dieter and Schellschmidt, R{\"u}diger}, title = {Temperature dependence of the relationship of thermal diffusivity versus thermal conductivity for crystalline rocks}, series = {International Journal of Earth Sciences}, volume = {97}, journal = {International Journal of Earth Sciences}, number = {2}, issn = {1437-3262}, doi = {10.1007/s00531-007-0238-3}, pages = {435 -- 442}, year = {2008}, language = {en} } @article{BaierMottaghyZiegleretal.2008, author = {Baier, C. and Mottaghy, Darius and Ziegler, M. and Rath, V.}, title = {Numerische Simulation des Gefrierprozesses bei der Baugrundvereisung im durchstr{\"o}mten Untergrund}, series = {Bauingenieur}, volume = {83}, journal = {Bauingenieur}, number = {2}, issn = {0005-6650}, pages = {49 -- 60}, year = {2008}, language = {de} } @article{RathMottaghy2007, author = {Rath, V. and Mottaghy, Darius}, title = {Smooth inversion for ground surface temperature histories: estimating the optimum regularization parameter by generalized cross-validation}, series = {Geophysical Journal International}, volume = {171}, journal = {Geophysical Journal International}, number = {3}, issn = {1365-246X}, doi = {10.1111/j.1365-246X.2007.03587.x}, pages = {1440 -- 1448}, year = {2007}, language = {en} } @article{VogtMottaghyWolfetal.2010, author = {Vogt, C. and Mottaghy, Darius and Wolf, A. and Rath, V. and Pechnig, R. and Clauser, C.}, title = {Reducing temperature uncertainties by stochastic geothermal reservoir modelling}, series = {Geophysical Journal International}, volume = {181}, journal = {Geophysical Journal International}, number = {1}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1365-246X}, doi = {10.1111/j.1365-246X.2009.04498.x}, pages = {321 -- 333}, year = {2010}, abstract = {Quantifying and minimizing uncertainty is vital for simulating technically and economically successful geothermal reservoirs. To this end, we apply a stochastic modelling sequence, a Monte Carlo study, based on (i) creating an ensemble of possible realizations of a reservoir model, (ii) forward simulation of fluid flow and heat transport, and (iii) constraining post-processing using observed state variables. To generate the ensemble, we use the stochastic algorithm of Sequential Gaussian Simulation and test its potential fitting rock properties, such as thermal conductivity and permeability, of a synthetic reference model and—performing a corresponding forward simulation—state variables such as temperature. The ensemble yields probability distributions of rock properties and state variables at any location inside the reservoir. In addition, we perform a constraining post-processing in order to minimize the uncertainty of the obtained distributions by conditioning the ensemble to observed state variables, in this case temperature. This constraining post-processing works particularly well on systems dominated by fluid flow. The stochastic modelling sequence is applied to a large, steady-state 3-D heat flow model of a reservoir in The Hague, Netherlands. The spatial thermal conductivity distribution is simulated stochastically based on available logging data. Errors of bottom-hole temperatures provide thresholds for the constraining technique performed afterwards. This reduce the temperature uncertainty for the proposed target location significantly from 25 to 12 K (full distribution width) in a depth of 2300 m. Assuming a Gaussian shape of the temperature distribution, the standard deviation is 1.8 K. To allow a more comprehensive approach to quantify uncertainty, we also implement the stochastic simulation of boundary conditions and demonstrate this for the basal specific heat flow in the reservoir of The Hague. As expected, this results in a larger distribution width and hence, a larger, but more realistic uncertainty estimate. However, applying the constraining post-processing the uncertainty is again reduced to the level of the post-processing without stochastic boundary simulation. Thus, constraining post-processing is a suitable tool for reducing uncertainty estimates by observed state variables.}, language = {en} } @article{MottaghyRath2006, author = {Mottaghy, Darius and Rath, Volker}, title = {Latent heat effects in subsurface heat transport modelling and their impact on palaeotemperature reconstructions}, series = {Geophysical Journal International}, volume = {164}, journal = {Geophysical Journal International}, number = {1}, issn = {1365-246X}, doi = {10.1111/j.1365-246X.2005.02843.x}, pages = {236 -- 245}, year = {2006}, language = {en} } @article{MottaghySchellschmidtPopovetal.2005, author = {Mottaghy, Darius and Schellschmidt, R. and Popov, Y. A. and Clauser, C. and Kukkonen, I. T. and Nover, G. and Milanovsky, S. and Romushkevich, R. A.}, title = {New heat flow data from the immediate vicinity of the Kola super-deep borehole: Vertical variation in heat flow density confirmed and attributed to advection}, series = {Tectonophysics}, volume = {401}, journal = {Tectonophysics}, number = {1-2}, issn = {1879-3266}, doi = {10.1016/j.tecto.2005.03.005}, pages = {119 -- 142}, year = {2005}, language = {en} } @article{WalterBorchert2002, author = {Walter, G. and Borchert, J{\"o}rg}, title = {Der Einsatz von Realoptionen in der Elektrizit{\"a}tswirtschaft}, series = {M \& A Review}, journal = {M \& A Review}, number = {4}, issn = {1616-0878}, pages = {198}, year = {2002}, language = {de} } @article{JungbluthBorchert2008, author = {Jungbluth, Christian and Borchert, J{\"o}rg}, title = {M{\"o}glichkeiten der Strompreisbeeinflussung im oligopolistischen Markt}, series = {ZNER Zeitschrift f{\"u}r Neues Energierecht}, journal = {ZNER Zeitschrift f{\"u}r Neues Energierecht}, number = {4}, pages = {314 -- 323}, year = {2008}, language = {de} } @article{BorchertSchemm2007, author = {Borchert, J{\"o}rg and Schemm, R.}, title = {Einsatz der Portfoliotheorie im Asset Allokations-Prozess am Beispiel eines fiktiven Anlageraumes von Windkraftstandorten}, series = {Zeitschrift f{\"u}r Energiewirtschaft}, volume = {31}, journal = {Zeitschrift f{\"u}r Energiewirtschaft}, number = {4}, issn = {0343-5377}, pages = {311}, year = {2007}, language = {de} } @article{BorchertHasenbeck2009, author = {Borchert, J{\"o}rg and Hasenbeck, Marc}, title = {Bewertung und Steuerung von Kraftwerksscheiben}, series = {Zeitschrift f{\"u}r Energiewirtschaft}, volume = {33}, journal = {Zeitschrift f{\"u}r Energiewirtschaft}, number = {2}, publisher = {Vieweg}, address = {Wiesbaden}, issn = {1866-2765}, doi = {10.1007/s12398-009-0014-0}, pages = {115 -- 126}, year = {2009}, language = {de} } @article{BorchertHasenbeckJungbluthetal.2009, author = {Borchert, J{\"o}rg and Hasenbeck, Marc and Jungbluth, Christian and Schemm, Ralf}, title = {Bewertung und Steuerung von Gasspeichern bzw. Gasspeicherscheiben}, series = {Zeitschrift f{\"u}r Energiewirtschaft}, volume = {33}, journal = {Zeitschrift f{\"u}r Energiewirtschaft}, number = {4}, publisher = {Springer}, address = {Berlin}, issn = {1866-2765}, doi = {10.1007/s12398-009-0033-x}, pages = {279 -- 293}, year = {2009}, abstract = {In diesem Artikel werden zun{\"a}chst einleitend der Gasmarkt Deutschland und der sich daraus ergebende Speicherbedarf skizziert. Folgend wird auf verschiedene Speichernutzen aus betriebswirtschaftlicher Perspektive eingegangen und die in diesem Artikel vorgestellten Bewertungsverfahren einleitend beschrieben. In diesem Artikel werden stochastische Optimierungsmethoden aufgegriffen, die sowohl eine Bewertung der Speicher gegen{\"u}ber einem Spotpreis, als auch gegen{\"u}ber einer gesamten Forwardcurve erm{\"o}glichen. Hierzu werden zun{\"a}chst Modelle zur Beschreibung der Marktpreise vorgestellt und anhand empirischer Daten kalibriert. Dann wird eine beispielhafte Speicherscheibe zun{\"a}chst auf Basis der LeastSquareMonteCarloTechnik gegen{\"u}ber dem stochastischen mehrfaktoriellen Spotpreismodell bewertet. Hieran schließt sich die Vorstellung der Bewertung sowie des Hedgings gegen{\"u}ber der Forwardcurve an. Abschließend erfolgt eine vergleichende Gegen{\"u}berstellung beider Verfahren.}, language = {de} } @article{JildehWagnerSchoeningetal.2015, author = {Jildeh, Zaid B. and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Pieper, Martin}, title = {Simulating the electromagnetic-thermal treatment of thin aluminium layers for adhesion improvement}, series = {Physica status solidi (a)}, volume = {Vol. 212}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201431893}, pages = {1234 -- 1241}, year = {2015}, abstract = {A composite layer material used in packaging industry is made from joining layers of different materials using an adhesive. An important processing step in the production of aluminium-containing composites is the surface treatment and consequent coating of adhesive material on the aluminium surface. To increase adhesion strength between aluminium layer and the adhesive material, the foil is heat treated. For efficient heating, induction heating was considered as state-of-the-art treatment process. Due to the complexity of the heating process and the unpredictable nature of the heating source, the control of the process is not yet optimised. In this work, a finite element analysis of the process was established and various process parameters were studied. The process was simplified and modelled in 3D. The numerical model contains an air domain, an aluminium layer and a copper coil fitted with a magnetic field concentrating material. The effect of changing the speed of the aluminium foil (or rolling speed) was studied with the change of the coil current. Statistical analysis was used for generating a general control equation of coil current with changing rolling speed.}, language = {en} } @article{MarxSchenkBehrensetal.2013, author = {Marx, Ulrich and Schenk, Friedrich and Behrens, Jan and Meyr, Ulrike and Wanek, Paul and Zang, Werner and Schmitt, Robert and Br{\"u}stle, Oliver and Zenke, Martin and Klocke, Fritz}, title = {Automatic production of induced pluripotent stem cells}, series = {Procedia CIRP : First CIRP Conference on BioManufacturing}, volume = {Vol. 5}, journal = {Procedia CIRP : First CIRP Conference on BioManufacturing}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2212-8271}, pages = {2 -- 6}, year = {2013}, language = {en} } @article{SrivastavaLahiriMaitietal.2014, author = {Srivastava, A. and Lahiri, S. and Maiti, M. and Knolle, F. and Hoyler, Friedrich and Scherer, Ulrich W. and Schnug, E. W.}, title = {Study of naturally occurring radioactive material (NORM) in top soil of Punjab State from the North Western part of India}, series = {Journal of Radioanalytical and Nuclear Chemistry}, volume = {2014}, journal = {Journal of Radioanalytical and Nuclear Chemistry}, number = {302}, publisher = {Springer Nature}, address = {Basel}, issn = {1588-2780 (E-Journal); 0022-4081 (Print); 0134-0719 (Print); 0236-5731 (Print); 1417-2097 (Print)}, doi = {0.1007/s10967-014-3450-1}, pages = {1049 -- 1052}, year = {2014}, language = {en} } @article{AlebouyehSamamiPieperBreitbachetal.2014, author = {Alebouyeh Samami, Behzad and Pieper, Martin and Breitbach, Gerd and Hodapp, Josef}, title = {Heat production in the windings of the stators of electric machines under stationary condition}, series = {Heat and mass transfer}, volume = {50}, journal = {Heat and mass transfer}, publisher = {Springer}, address = {Heidelberg}, issn = {0947-7411 (Print) ; 1432-1181 (E-Journal)}, doi = {10.1007/s00231-014-1371-8}, pages = {1707 -- 1716}, year = {2014}, abstract = {In electric machines due to high currents and resistive losses (joule heating) heat is produced. To avoid damages by overheating the design of effective cooling systems is required. Therefore the knowledge of heat sources and heat transfer processes is necessary. The purpose of this paper is to illustrate a good and effective calculation method for the temperature analysis based on homogenization techniques. These methods have been applied for the stator windings in a slot of an electric machine consisting of copper wires and resin. The key quantity here is an effective thermal conductivity, which characterizes the heterogeneous wire resin-arrangement inside the stator slot. To illustrate the applicability of the method, the analysis of a simplified, homogenized model is compared with the detailed analysis of temperature behavior inside a slot of an electric machine according to the heat generation. We considered here only the stationary situation. The achieved numerical results are accurate and show that the applied homogenization technique works in practice. Finally the results of simulations for the two cases, the original model of the slot and the homogenized model chosen for the slot (unit cell), are compared to experimental results.}, language = {en} } @article{Kuperjans1996, author = {Kuperjans, Isabel}, title = {Exergetische und exergo{\"o}konomische Analyse thermischer Prozesse}, series = {Arbeitsbericht / Institut f{\"u}r Wirtschaftswissenschaften, Rheinisch-Westf{\"a}lische Technische Hochschule Aachen}, journal = {Arbeitsbericht / Institut f{\"u}r Wirtschaftswissenschaften, Rheinisch-Westf{\"a}lische Technische Hochschule Aachen}, number = {06}, year = {1996}, language = {de} }