TY - GEN A1 - Lechner, Stefan A1 - Merzsch, Matthias A1 - Krautz, Hans Joachim T1 - Heat-transfer from horizontal tube bundles into fluidized beds with Geldart A lignite particles T2 - Powder Technology N2 - This work investigates the heat transfer mechanism in fluidized beds equipped with horizontal heat exchanger surfaces such as single tubes and especially tube bundles. Previous works were performed for varying operating conditions and solids' material properties, leading to a heterogeneous and therefore not applicable spectrum of derived correlations for the influence of tube diameter and tube bundle geometry on heat transfer. Based on a wide range validation of the correlation for the influence of single tube diameter on heat transfer coefficient, tube bundles with different tube diameters and horizontal and vertical spacings and alignments were investigated. Experiments were carried out using electrical heat transfer probes in a 0.15 m2 fluidized bed test facility at ambient conditions. Geldart A lignite and Geldart D solids were used in order to distinguish between predominant particle-convective and gas-convective heat transfer mechanisms. The tube bundle reduction factor on heat transfer coefficient was derived as a key parameter based on dimensionless geometric numbers. This factor predicts the reduction of the heat transfer coefficient compared to that of the single tube due to the particle and gas flow disturbances caused by the immersed tubes. Tube diameter as well as tube bundle geometry were successfully implemented into useful correlations for predicting tube bundles' heat transfer of gas–solid fluidized bed systems operating with fine particles. KW - Fluidized bed KW - Lignite KW - Drying KW - Heat transfer KW - Horizontal tubes KW - Tube bundle Y1 - 2014 U6 - https://doi.org/10.1016/j.powtec.2013.10.041 IS - 253 SP - 14 EP - 21 ER - TY - CHAP A1 - Ziems, Christian A1 - Tillmann, Christine A1 - Krautz, Hans Joachim T1 - H2-Forschung an der BTU Cottbus T2 - 4. Energiefachtagung, Cottbus, 2012 Y1 - 2012 ER - TY - THES A1 - Höhne, Olaf T1 - Grundlagenuntersuchungen zum Einfluss des Systemdrucks auf die Trocknung von Braunkohle in Wasserdampf Y1 - 2012 UR - http://www.cuvillier.de/flycms/de/html/30/-UickI3zKPS3wdUg=/Buchdetails.html SN - 978-3-9540407-6-6 PB - Cuvillier CY - Göttingen ER - TY - CHAP A1 - Ziems, Christian A1 - Tannert, Daniel A1 - Krautz, Hans Joachim T1 - Grundlagenforschung zur Optimierung des alkalischen Druckelektrolyseprozesses am 25 bar Einzel-Zell-Versuchsstand - Projektvorstellung T2 - 19. Symposium - Nutzung regenerativer Energiequellen und Wasserstofftechnik, 8. - 10. November 2012 Stralsund Y1 - 2012 SN - 978-3-9813334-5-9 PB - Fachhochschule CY - Stralsund ER - TY - CHAP A1 - Ziems, Christian A1 - Krautz, Hans Joachim T1 - Grid integration of renewable energies and hydrogen research at BTU Cottbus T2 - Dena Konferenz "Power to Gas - innovative Systemlösungen für ein zukunftsfähiges Energiesystem entwickeln", Berlin, 2012 Y1 - 2012 ER - TY - JOUR A1 - Kalina, Hartmut A1 - Löffler, Steffen A1 - Krautz, Hans Joachim A1 - Möller, J. T1 - Gesamtbewertung für erneuerbare Energien möglich und sinnvoll Y1 - 2005 ER - TY - GEN A1 - Horsfield, B. A1 - Scheck-Wenderoth, Magdalena A1 - Krautz, Hans Joachim A1 - Mutti, M. T1 - Geoenergy: From visions to solutions KW - CCS Y1 - 2010 U6 - https://doi.org/http://dx.doi.org/10.1016/j.chemer.2010.06.002 ER - TY - CHAP A1 - Menke, Dominik A1 - Klatt, Matthias A1 - Krautz, Hans Joachim A1 - Gade, Udo A1 - Mandel, Hans T1 - Gemeinsame Analyse der Prozesstechnik und Verfügbarkeit moderner Großkraftwerke Y1 - 2001 ER - TY - CHAP A1 - Klatt, Matthias A1 - Warnecke, Martin T1 - Gedanken zur Instandhaltungsperiodenbestimmung mit generischen Algorithmen Y1 - 2005 ER - TY - THES A1 - Tappe, Stephanie T1 - Gaspotentiometrische und thermogravimetrische Abbranduntersuchungen vom Braun- und Steinkohlen in Luft und in O2/CO2-Atmosphären Y1 - 2011 UR - http://www.shaker.de/de/content/catalogue/Element.asp?ID=&Element_ID=42103&Mode=PageFrame SN - 978-3-8440-0290-4 PB - Aachen : Shaker ER -