Fuel Cell Module

The singular fuel cell is characterized by relatively low voltage in the range from 1.1 to 0.4 V. Those values are very impractical, and cells are connected in series to obtain more convenient voltages ( 100V). This construction makes a fuel cell 

An example of an SOFC Module proposed by Siemens is shown in Fig. 5.35. The module is composed of the following main devices  

The air, mostly from behind the compressor, is directed to a regenerative heat exchanger inside the fuel cell module. Then air taken from the pipe system passes through the combustion chamber and the recycle plenum, entering the cathode side of the fuel ceU stack. An outlet of the cathode ends in the combustion chamber, where the air mixes with the anodic gases. 

Electricity generated by the entire SOFC module is determined by the following equation  

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Initial systems will be less than 20 MW, with typical system sizes of 1 to 10 MW. Future systems, in the megawatt class size, will boost efficiency even further by combining two solid oxide fuel cell modules with more advanced gas turbines and introducing sophisticated cooling and heating procedures. 

The Siemens Westinghouse TSOFC commercialization plan is focused on an initial offering of a hybrid fuel cell/gas turbine plant. The fuel cell module replaces the combustion chamber of the gas turbine engine. Figure 1-8 shows the benefit behind this combined plant approach. Additional details are provided in Section 8. As a result of the hybrid approach, the 1 MW early commercial unit is expected to attain -60% efficiency LHV when operating on natural gas. 

Table 9-15 Example Fuel Utilization in a Multi-Stage Fuel Cell Module...

The hot processed fuel and the compressed ambient air are electrochemically combined within the fuel cell module. The fuel hydrocarbons still remaining after the mild reformer are reformed within the fuel cell. The heat required for the endothermic steam reforming reactions is supplied by the exothermic fuel cell reactions. The overall reactions are exothermic, and the fuel and oxidant temperatures rise to 999°C (1830°F) (streams 8 and 12). The fuel cell is capable of utilizing both H2 and CO as fuel and has an overall fuel utilization of 94%. 

The spent fuel (stream 8) and oxidant (stream 12) are combusted upon exiting the multi-stage fuel cell module. The resulting exhaust stream (stream 13) has a temperature of 1119°C (2046°F) before being cooled in a fuel heater and expanded to 1.04 atmospheres and 856°C (1573°F) (stream 15). This nearly atmospheric exhaust stream passes through several additional heat exchangers before leaving the plant stack at 147°C (300°F). 

The example is the fuel cell module of commercial CFD software FLUENT . As was already mentioned, it is a set of additional subroutines (on top of Navier-Stokes equations and other transport models in CFD) to account for electrochemistry inside... 

FLUENT 6.2 (2005) Fuel Cell Modules Manual, FLUENT Inc., Lebanon, NH. 

The cost includes the fuel cell module, precious metals, the fuel processor, compressed hydrogen storage, balance of plant, and assembly, labor, and depreciation. 

The Rolls-Royce fuel cell modules and stacks are devoid of compliant features, as the cross-section in Figure 4.3 shows, unless one counts the gap as compliant. Cell improvement is clearly possible via thin (say 6 p.m) electrolyte layers, as employed in a planar IT/SOFC by Global Thermoelectric (Section 4.9) and Steele etal. (2000a, b). Alternatively, modern reduced temperature electrolytes could be used. 

But another important complication is related to a not uniform distribution of humidity inside the electrolyte and on the catalyzed electrodes, and to the eventuality of incipient flooding phenomena, due to an excess of water bulked inside the fuel cell module that could dangerously limit the reactant entrance to active sites of catalyzed electrodes. This phenomenon could be present also without external water addition, because dry air streams entering into the ceU module gradually moisturize creating the possibility of local flooding at the end of their path [28]. 

John Deere is testing fuel cell modules for off-road applications. Hydrogen is considered a good replacement for diesel in locomotives. Recent testing indicates that it could be economical for railroads. 

The fuel cell module takes a hydrogen inlet flow rate and a requested power, then determines if sufficient power can be supplied. The stack model uses a simple map of efficiency versus power. This data is read from an input file to allow the fuel cell to be calibrated to real performance data. If sufficient... 

Figure 6.2 (a) Assembly of alkaline fuel-cell modules for Project Apollo missions ... 

In the project Fuel Cell Bus, sponsored by the state of Bavaria, a consortium of German industrial companies is planning to realize a zero-emission low-floor bus by the year 1999 [18]. The basis is an MAN bus whose conventional diesel engine will be replaced by four PEM fuel cell modules with a rated ouqiut of 120 kW (Fig. 9-10). The hydrogen fuel will be stored as compressed gas at 25 MPa in nine pressure bottles on the roof, sufficient for a 250 km cruising range. 

ANON, Hydrogen Fed 850 kW Fuel Cells Module for Chemical Industry, World Wide Web, http //www.ansaldo.it/CLC.module.htm, Ansaldo (1998). 

After the analysis of PCFB-1.0 plant design documentation, the circuit of new hybrid co-generation power plant with use of PCFB gasifier, solid oxide fuel cells, and gas turbine power plant with built-in air recuperator was proposed (see Fig. 7). Thermal capacity of power plant will be 1.14 MW at gasifier operation under pressure of 0.35 MPa and Ukrainian bituminous coal consumption of 222.6 kg/h. Electric capacity of solid oxide fuel cell module will be 375 kW and of electric capacity of high-speed gas turbine plant will be 125 kW. 

An alternative could be a fuel cell module. In order to keep the design simple and the operation reliable it is sufficient to use as main components, a fuel cell, an oxygen gas cylinder, an H2 gas cylinder, control valves and cooling. The functionality could be easily tested at any time when installed by an appropriate monitoring system (Fig. 5.6). 

The companies FutureE and Rittal have developed a modular slide-in system that can be scaled at 2 kW steps, and thus a N + 1 redundancy is enabled in the fuel cell modules. Figure 7.5 shows such a system as a protection of a switching unit in the energy sector. 

Kurz, T. and Keller, J. (2011) Heat management in a portable high temperature PEM fuel cell module with open cathode. Fuel Cells, 11 (4), 518-525. 

Peksen, M. (2011) Fuel cell module, European patent application EP 2 372 825 Al. 

The conceptual layout of the power island was prepared to facilitate the Factory Cost estimation. As shown in Figure 2, the power island consists of 8 sections each containing 42 fuel cell modules. The module Sections are grouped with 4 Sections on each side of the centralized Power Island equipment. The footprint of the IGFC plant was found to be comparable to an IGCC plant. Recent Factory Cost Estimates have shown an SOFC power island cost of 635/kW in 2007 US dollars, meeting the DOE cost target of < 700/kW. 

Serenergy (2010) Serenus methanol fuel cell module - 350W. http //www.seienergy.com/files/ assets/documentation/Seienus%20H3%20E-350 datasheet vl.l-0210.pdf... 

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