Experimental Analysis of the Voltage and Temperature Behavior of a Solid Oxide Fuel Cell Generator

A solid oxide fuel cell (SOFC) laboratory has been installed in Torino, Italy, in order to analyze the operation, in a cogenerative configuration, of the CHP-100 SOFC Field Unit built by Siemens Power Corporation (SPG) Stationary Fuel Cells (SFC), within the framework of the EOS Project. An experimental session was performed, varying the setpoint temperature T GEN and the fuel consumption (FC), with the aim of characterizing the behaviour of the local voltages and temperatures. A design of experiments procedure was applied to obtain first (simple 2 2 ) and second-order (spherical central composite design (CCD)) regression models, which were then used in subsequent constrained optimization procedures. A sensitivity analysis was also performed: FC revealed as the prevailing control factor of the operation, and it was shown that the analysis of the local voltage and temperature sensitivity to FC can be used as a diagnostic tool for the fuel distribution within a SOFC generator (the homogeneity of the sensitivity of the various cells was ∼10%, depending strongly on the cell bundle arrangement in the stack). Finally, the effect of any changes in the control factors on the tube temperature profile was evaluated and discussed; a link between a high terminal voltage and a more uniform temperature along the cell tube has been pointed out.

[1]  G. Orsello,et al.  The EOS Project: a SOFC pilot plant in Italy- safety aspects , 2005 .

[2]  Pierluigi Leone,et al.  Computer experimental analysis of a tubular SOFC CHP to evaluate factors effects on performances and S/C ratio , 2005 .

[3]  R. H. Myers,et al.  Probability and Statistics for Engineers and Scientists , 1978 .

[4]  N. Bessette,et al.  A Mathematical Model of a Solid Oxide Fuel Cell , 1995 .

[5]  Rory A. Roberts,et al.  Dynamic Simulation of a Pressurized 220kW Solid Oxide Fuel-Cell–Gas-Turbine Hybrid System: Modeled Performance Compared to Measured Results , 2006 .

[6]  Massimo Santarelli,et al.  Experimental analysis of the CHP performance of a PEMFC stack by a 24 factorial design , 2005 .

[7]  Gianfranco DiGiuseppe,et al.  Fuel sensitivity tests in tubular solid oxide fuel cells , 2004 .

[8]  Whitney Colella,et al.  Modelling results for the thermal management sub-system of a combined heat and power (CHP) fuel cell system (FCS) , 2003 .

[9]  Ashok Rao,et al.  Analysis and optimization of a solid oxide fuel cell and intercooled gas turbine (SOFC-ICGT) hybrid cycle , 2004 .

[10]  Raphaël Ihringer,et al.  Dynamic behaviour of SOFC short stacks , 2006 .

[11]  M. Chyu,et al.  Simulation of the chemical/electrochemical reactions and heat/mass transfer for a tubular SOFC in a stack , 2003 .

[12]  Pierluigi Leone,et al.  Computer experimental analysis of the CHP performance of a 100 kW e SOFC Field Unit by a factorial design , 2006 .

[13]  Paola Costamagna,et al.  Modeling of Solid Oxide Heat Exchanger Integrated Stacks and Simulation at High Fuel Utilization , 1998 .

[14]  J. Brouwer,et al.  Fuel flexibility study of an integrated 25 kW SOFC reformer system , 2005 .

[15]  Pierluigi Leone,et al.  Comparison of the behaviour of the CHP-100 SOFC Field Unit fed by natural gas or hydrogen through a computer experimental analysis , 2005 .