Siemens operational problems

Currently, there are two main technical solutions for the construction of SOFC flat or tubular. Cells with tubular structures have been proposed by Westinghouse (later bought by Siemens) and work as an experimental-prototype unit with power in the range 100-300 kW across the world (12 such units have been constructed in total). Units with output of 100 kW run at atmospheric pressure in the combined heat and power (CHP) configiuation, and with output of 220 kW as pressurized units in a gas turbine system. Cells with flat design are much easier to produce, but entail the use of certain seals and related operational problems. They are heralded for use mainly in household apphcations as co-generation units. 

Use of the rotary kiln technology on a technical scale depends strongly on the economics of the process. In the past several process types were tested and applied. Usually operative mode or shut down were not affected by technical problems, but by the profitability of the processes. One example is the Siemens-KWU process. It has been... 

From the structure point of view, there are two types of structures of SOFC tubular and planar. Tubular SOFCs have shown some desirable characteristics over systems with planar SOFCs [4]. Tubular SOFCs can alleviate the sealing problem arose by CTE mismatch of planar SOFC therefore, they are robust for repeated cycling under rapid changes in electrical load and in cell operating temperatures. The large form factor tubular SOFC built by Siemens Westinghouse has successfully conducted long-term operation over 70,000 h. Small-scale tubular SOFCs could... 

As Hybrex requires a certain operation system (Windows NT) and Microsoft s Office suite, it is difficult to supply a potential customer with a demo version running on any client. Also the material database used by Hybrex is not intended to be supplied to anyone, because it holds a lot of Siemens know how and research data of the last two decades flow curves, material values etc., valuable and strictly confidential data, Siemens would not want to give outside. Solutions like dongles for the software cause logistic problems. Encryption of the material database solved this issue, but perhaps are not safe for all time. 

Contrary to worldwide steam generator tube degradation problems, steam generators of the Siemens/KWU design operated in Germany have proved by operating experience their low sensitivity to tube corrosion or any other steam-generator-tubes-related problems. 

---