Veröffentlichungen

@incollection{Pohl.2017b,

title = {Experimental plant balancing and cell voltage analysis of a high temperature proton exchange membrane fuel cell stack with natural gas fuel processor},

author = {Elmar Pohl and Frank Beckmann and Carlo Tregambe},

editor = {Isotta Cerri and Angelika Heinzel},

isbn = {978-3-905592-22-1},

year  = {2017},

date = {2017-01-01},

booktitle = {Proceedings of 6th European PEFC & Electrolyser Forum 2017},

publisher = {European Fuel Cell Forum AG},

address = {Luzern-Adligenswil, Switzerland},

keywords = {Fuel Cell, PEM},

pubstate = {published},

tppubtype = {incollection}

}

@incollection{Pohl.2017c,

title = {Improved performance of modular HT-PEM based CHP systems considering seasonal effects and degradation effects},

author = {Elmar Pohl and David Diarra},

editor = {Isotta Cerri and Angelika Heinzel},

isbn = {978-3-905592-22-1},

year  = {2017},

date = {2017-01-01},

booktitle = {Proceedings of 6th European PEFC & Electrolyser Forum 2017},

publisher = {European Fuel Cell Forum AG},

address = {Luzern-Adligenswil, Switzerland},

abstract = {In the European joint research project CISTEM, a modular combined heat and power (CHP) system based on high temperature proton exchange membrane (HT-PEM) fuel cells is developed. The system consists of 10 modules, each with one steam reformer and two HT-PEM stacks. The electrical output per module is up to 8 kW. In order to calculate the primary energy savings (PES) of a CHP system, the fuel demand of the CHP system is compared to conventional separated heat and power generation (boiler and electrical grid). The impact of seasonal effects and performance loss on PES in a modular CHP system is presented in this contribution. In a first step, the demand side and the fuel cell based CHP modules are described. With the data a complete performance map is set up in a second step. The performance map describes the relation of characteristic process parameters (fuel utilization and fuel input) on electrical power output and efficiency. A major benefit of modular fuel cell systems is that the power to heat ratio can be modified in each module. The total amount of generated heat and power can be modified by the number of operating modules. For an optimized operation, following strategy is analyzed in a third step: In winter terms, a lower power to heat ratio is needed than in summer terms. Hence, the operation is performed with high current densities in winter and low current densities in summer. Over time the module suffer losses, represented by a declining polarization curve of the fuel cell stack. In order to remain the power to heat ratio constant, the operating point of the stack is switched towards lower current densities. The stack voltages are held constant for summer and winter mode respectively. Since the total power output per module decreases, more modules are switched on over time. The performance loss is compensated with more operating modules. The numerical analysis show that PES of above 20% is possible compared to separated heat and power generation. The presented operation strategy considers irreversible performance losses and shows how to achieve a high PES level over a theoretical operating time of about 40,000 hours per module. The operating hours are estimated defining 80% of the initial operating point as end of life. Typical degradation rates of the stacks were determined within this project. As a side effect, the CHP module reaches high operating hours per year which also improves economy.},

keywords = {Fuel Cell, PEM},

pubstate = {published},

tppubtype = {incollection}

}

@incollection{Pohl.2014d,

title = {Novel approach for degradation modeling of HT-PEM fuel cells using dual time scale simulation},

author = {Elmar Pohl and Jörg Schloß and Ansgar Bauschulte and Marius Maximini},

year  = {2014},

date = {2014-01-01},

booktitle = {11th Symposium for Fuel Cell and Battery Modelling and Experimental Validation},

keywords = {Fuel Cell, PEM, Reforming},

pubstate = {published},

tppubtype = {incollection}

}

@incollection{Wruck.2009,

title = {Untersuchung der katalytischen Verbrennung von Heizöl EL im Hinblick auf die Einsatzfähigkeiten in einem PEM-Brennstoffzellensystem},

author = {Roland Wruck and S. Tölle and Melanie Grote and Klaus Lucka and Heinrich Köhne},

editor = {Heinrich Köhne and Klaus Lucka},

isbn = {978-3-8322-8484-8},

year  = {2009},

date = {2009-01-01},

booktitle = {6. Aachener Ölwärme-Kolloquium},

volume = {28},

pages = {170--179},

publisher = {Shaker},

address = {Aachen},

series = {Berichte aus der Verbrennungstechnik},

keywords = {Fuel Cell, PEM},

pubstate = {published},

tppubtype = {incollection}

}