Versa Power Systems

FuelCell Energy is a partner with Versa Power Systems, Nexant, and Gas Technology Institute to develop more affordable fuel-cell-based technology that uses synthesis gas from a coal gasifier. The key objectives include the development of fuel cell technologies, fabrication processes, and manufacturing capabilities for solid oxide fuel cell stacks for multi-mega-watt power plants. 

The gas supply to the stack is accomplished using either external manifolds, usually made of stainless steel, or internal manifolds (Versa Power Systems, HT-ceramix). In the latter case, the manifolds are integrated into the cell design and interconnect (Delphi). 

Fig. 5.1 Commonly used SOFC designs (Celik, 2006). (a) Tubular SOFC, (b) 24 cell tubular SOFC stack, (c) a tubular SOFC module with 48 stacks, (d) 28 cell internally manifolded stack design by Versa Power Systems.

To solve the problem in the electrolyte-supporting cell, anode-supported cells have been developed. Since a thin electrolyte is fabricated on a thick anode, the ohmic resistance of the electrolyte can be reduced. The low resistance of the electrolyte implies that the anode-supported cell can be operated at a low temperature below 800°C. As a result, commercial alloys can be used as the interconnectors and auxiliaries. Using the alloys improves the mechanical reliability of the cell stack. For several years, Versa Power Systems have developed several kW systems with anode-supported cells and have demonstrated the performance of such systems [5],... 

Tang, E., Prediger, D., Pastula, M. and Borglum, B., The status of SOFC development and Versa Power Systems, in Proceedings of Solid Oxide Fuel Cells IX, The Electrochemical Society Proceedings, Electrochemical Society, Pennington, NJ, 2005, p. 89. 89(2005). 

Tang, E., Pastula, M., Wood, T., and Borglum, B. (2009) 10 kW SOFC Cell and Stack Development at Versa Power Systems in Proceedings of the 33rd International Conference on Advanced Ceramics and Composites, Daytona Beach, FL. 

Similar concepts have been developed, for example, by Versa Power Systems (VPS) in Canada, Delphi and PNNL in the USA, and Topsoe Fuel Cells and Ris0... 

As mentiOTied previously, Siemens/Westing-house is no longer in the SOFC business. However, other organizations are cmitinuing work on large-scale SOFC systems. Chief among these are Versa Power Systems... 

A number of companies are working with SOFCs. Some of the main players relevant to this text are Ceramic Fuel Cells, Ceres Power, Kyocera, MHI, Rolls Royce Fuel Cells, Siemens Westinghouse and Versa Power Systems (Figures 2.12 and 2.13). 

Some alternative ways of tackling the sealing problem in stack have also been attempted using metallic gaskets, o-ring etc. (Bram et al. 2001, Duquette et al. 2004). Their studies concentrated on the influence of contact load and internal pressure on the deformation behavior of various metallic gaskets, different in shape and fabricated from different alloys. The testing was carried out at room temperature. However, more work is necessary to establish issues related to its applicability at 800°C. Versa Power Systems Ltd. 

We will notice subsequently that series and shunt compensation are complementary. What a shunt capacitor cannot do, a series capacitor does and vice versa. On a secondary transmission system, say up to 66 kV, a shunt compensation may always be necessary to improve the power factor, as the load would mainly be indtictive. A series compensation may become essential, to improve the stability of the system, to cope with load fluctuations, switching of non-linear loads and voltage fluctuations occurring on the other power system or the grid to which this system may be connected. 

LGs can also serve as powerful alternatives to PDEs themselves in modeling physical systems. The distinction is an important one. It must be remembered, however, that not all PDEs (and perhaps not all physical systems see chapter 12) are amenable to a LG simulation. Moreover, even if a candidate PDE is selected for simulation by a LG. there is no currently known cookbook recipe allowing a researcher to go from the PDE to a LG description (or vice versa). Nonetheless, by their very nature, LGs lend themselves to modeling any partial differential equation (PDE) for which the underlying physical basis for its construction involves a large number of particles with local interactions [wolf86c]. 

For energy security reasons, the presence of an auxiliary power supply unit is necessary. This unit can be preferably either a hydrogen internal combustion engine (H2 ICE) or a fuel cell of corresponding capacity to meet at least the minimum needs of the system. In this case, the system is an autonomous power plant. Figure 5.11 shows a stand-alone wind-hydrogen system that is autonomous. The dashed line in some parts of it implies that these connections may not exist as well. The DC/AC converter/controller should have the capability to operate vice versa and power up the lines through the power controller. 

In the above example, the process characteristics (here, power characteristics) presenting a comprehensive description of the process were evaluated. This often expensive and time-consuming method is certainly not necessary if one has to only scale-up a given process condition from the model to the industrial plant (or vice versa). With the last example and the assumption that the Ne (0 characteristics like those in Figure 3 are not explicitely known, the task is to predict the power consumption of a Rushton turbine of rotating with = 200/min. The air throughput be = 500m /hr and the material system is water/air. 

To overcome these difficulties, Povarnin proposed his theory of polar affinities, in which he assumed that atoms themselves are complex systems of positive and negative affinities in unequal amounts so that an element is positive when the positive charge exceeds the negative, and negative when the situation is vice versa. He therefore regarded the classical unit of valency as composed of two polar charges not identical in absolute magnitude. He postulated that bonds between atoms have the power to oscillate and that atoms tend to form four- or six-membered cyclic molecules. 

Local-rank constraints are related to mathematical properties of a data set and can be applied to all data sets, regardless of their chemical nature. These types of constraints are associated with the concept of local rank, which describes how the number and distribution of components varies locally along the data set. The key constraint within this family is selectivity. Selectivity constraints can be used in concentration and spectral windows where only one component is present to completely suppress the ambiguity linked to the complementary profiles in the system. Selective concentration windows provide unique spectra of the associated components, and vice versa. The powerful effect of these type of constraints and their direct link with the corresponding... 

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