IN THIS RESEARCH, THREE-DIMENSIONAL MODEL FOR A PLANAR Solid OXIDE fuel CELL WAS DEVELOPED, WHICH INCLUDES THE FLOW CHANNELS, ELECTRODES, CURRENT COLLECTORS, AND ELECTROLYTE. THE PROPOSED MODEL INCLUDES MASS AND MOMENTUM TRANSPORT IN THE FLOW CHANNELS AND ELECTRODES, ELECTROCHEMICAL REACTION IN ELECTRODES, AND CHARGE TRANSFER IN ALL PARTS OF fuel CELL.THE MOST IMPORTANT CHARACTERISTIC OF THIS MODEL IS CONSIDERATION OF ALL ELECTRODES’ THICKNESS AS TRIPLE PHASE BOUNDARIES, THIN LAYERS IN THE VICINITY OF THE ELECTROLYTE, WHERE THE ELECTROCHEMICAL REACTIONS TAKE PLACE AND PRODUCE ELECTRONS, OXIDE IONS AND WATER VAPOR.IT WAS OBSERVED THAT THE CONCENTRATION PROFILE OF HYDROGEN AND OXYGEN DECREASES WITH INCREASING THE VOLTAGE OF CELL ALONG THE fuel CHANNELS AND ELECTRODES. FURTHERMORE, OUT RESULTS SHOWED THAT THE CONCENTRATION OF GASES, AS WELL AS THE RATE OF REACTION AND CURRENT DENSITY, INCREASES BY RISING THE TEMPERATURE. THE PERFORMANCE OF SOFC IS ALSO VALIDATED WITH MEASURED DATA FOUND IN THE LITERATURES AND GOOD AGREEMENT IS FOUND BETWEEN THE RESULTS OF THIS MODEL AND EXPERIMENTAL DATA.

THIS PAPER, PRESENTS A TWO DIMENSIONAL FINITE DIFFERENCE MODEL OF PLANAR Solid OXIDE fuel CELLS (SOFCS) WITH RESPECT TO CO AND COUNTER-FLOW CONFIGURATION. IN THIS WORK, SOFC IS DIVIDED INTO FIVE CONTROL-VOLUMES (fuel AND AIR CHANNEL, PEN STRUCTURE, fuel SIDE INTERCONNECT AND AIR SIDE INTERCONNECT). ELECTROCHEMICAL MODEL ARE DISCUSSED AND PARAMETERS SUCH AS ELECTROCHEMICAL REACTION AND POLARIZATION LOSSES ARE DEBATED. THE EQUATIONS ARE FINITE DIFFERENCE INTEGRAL FORMS THAT WERE ANALYZED BASED ON THE FINITE VOLUME FORM. NUMBER OF THE FINITE VOLUMES SHOULD BE DEFINED BY THE USER AND THE MORE THE FINITE VOLUMES CAUSE THE MORE ACCURATE MODEL. FOR EACH NODES IN THE CONTROL VOLUMES ELECTROCHEMICAL MODEL WERE WRITTEN.EACH NODE CONTAINS VCELL, VOHM, VCONC AND VACT OR, CAN BE SAID THAT EACH NODE CONTAINS VOLTAGE AND DIFFERENT POLARIZATIONS. ALSO EFFECT OF THE EFFECTIVE AND IMPORTANT PARAMETERS SUCH AS TEMPERATURE AND CURRENT DENSITY ON VOLTAGE AND EFFECT DENSITY ON ELECTRIC POWER FOR BOTH CONFIGURATIONS ARE INVESTIGATED. MOREOVER EFFECT OF CURRENT DENSITY ON DIFFERENT POLARIZATION IS DISCUSSED. THE RESULT SHOWED THAT TEMPERATURE INCREASE THE VOLTAGE. THE OPTIMUM CURRENT DENSITY IS CALCULATED AS 7222 (A/M2) (CO AND COUNTER-FLOW) ALSO INCREASING THE fuel UTILIZATION LEADS TO DECREASE THE VOLTAGE IN BOTH CONFIGURATION.

IN THIS RESEARCH, THREE-DIMENSIONAL MODEL FOR A PLANAR Solid OXIDE fuel CELL WAS DEVELOPED, WHICH INCLUDES THE FLOW CHANNELS, ELECTRODES, CURRENT COLLECTORS, AND ELECTROLYTE. THE PROPOSED MODEL INCLUDES MASS AND MOMENTUM TRANSPORT IN THE FLOW CHANNELS AND ELECTRODES, ELECTROCHEMICAL REACTION IN ELECTRODES, AND CHARGE TRANSFER IN ALL PARTS OF fuel CELL.THE MOST IMPORTANT CHARACTERISTIC OF THIS MODEL IS CONSIDERATION OF ALL ELECTRODES’ THICKNESS AS TRIPLE PHASE BOUNDARIES, THIN LAYERS IN THE VICINITY OF THE ELECTROLYTE, WHERE THE ELECTROCHEMICAL REACTIONS TAKE PLACE AND PRODUCE ELECTRONS, OXIDE IONS AND WATER VAPOR.IT WAS OBSERVED THAT THE CONCENTRATION PROFILE OF HYDROGEN AND OXYGEN DECREASES WITH INCREASING THE VOLTAGE OF CELL ALONG THE fuel CHANNELS AND ELECTRODES. FURTHERMORE, OUT RESULTS SHOWED THAT THE CONCENTRATION OF GASES, AS WELL AS THE RATE OF REACTION AND CURRENT DENSITY, INCREASES BY RISING THE TEMPERATURE. THE PERFORMANCE OF SOFC IS ALSO VALIDATED WITH MEASURED DATA FOUND IN THE LITERATURES AND GOOD AGREEMENT IS FOUND BETWEEN THE RESULTS OF THIS MODEL AND EXPERIMENTAL DATA.

OXIDATION RESISTANCE, AND THE LONG- TERM STABILITY OF INTERCONNECTS IN Solid OXIDE fuel CELLS, CAN BE AMELIORATED BY THE USE OF A PROTECTIVE, EFFECTIVE, RELATIVELY DENSE AND WELL ADHERENT COATING. FOR THIS AIM MN CAN BE DEPOSITED ON THE SURFACE OF METALLIC INTERCONNECTS BY PACK CEMENTATION PROCESS. IN THIS STUDY MN WAS DEPOSITED ONTO THE UNS 430 FERRITIC STAINLESS STEEL BY PACK CEMENTATION PROCESS. IN ORDER TO MAKE THE BEST CHARACTERISTICS OF THE FORMED COATING, THE EFFECTIVE FACTORS OF PACK CEMENTATION PROCESS WAS INVESTIGATED BY ALTERING THESE FACTORS, WHICH WERE SALT ACTIVATOR CONTENT IN THE PACK POWDER (2-6%W.T.), DEPOSITION TEMPERATURE (700-800 OC) AND DEPOSITION TIME (3-5 H). THE AS-COATED SAMPLES WERE EXAMINED WITH SCANNING ELECTRON MICROSCOPY (SEM) ASSOCIATED WITH ENERGY DISPERSIVE SPECTROSCOPY (EDS). IT WAS REVEALED THAT EACH PARAMETER AFFECT THE COATING THICKNESS, COATING QUALITY AND INTEGRITY.

IN THIS PAPER, NANOTECHNOLOGY APPLICATIONS ARE REVIEWED TO BE FABRICATED Solid OXIDE fuel CELLS WITH NOVEL STRUCTURES. NANOPARTICLES, NANO POWDERS, NANO-NETWORKS, NANOSTRUCTURES, AND NANO COMPOSITES ARE USED TO MAKE NANOSTRUCTURED LAYERS OF Solid OXIDE fuelS CELLS AS ANODES, ELECTROLYTES AND CATHODES. THESE NANOSTRUCTURED SOFCS ARE DEMONSTRATED MORE POWER DENSITY AT LOWER OPERATING TEMPERATURE. THESE RESULTS LEAD US TO MAKE NEW EFFECTIVE SOFCS WHICH ARE EXPLOITED NANOTECHNOLOGY TECHNIQUES.

Solid OXIDE fuel CELL (SOFC) IS A TYPE OF fuel CELLS IDENTIFIED AS THE LIKELY fuel CELL TECHNOLOGIES THAT WILL CAPTURE THE MOST SIGNIFICANT MARKET IN THE FUTURE. SOFC USES A SPECIAL Solid OXIDE CERMET (MOSTLY YTTRIA-STABILIZED ZIRCONIA, YSZ) AS THE ELECTROLYTE AND USUALLY WORKS AT A HIGH TEMPERATURE, IN THE RANGE OF 800-1000 OC TO REACH THE ELECTROLYTES IONIC CONDUCTIVITY REQUIREMENT. ...