Solid oxide fuel cells are high temperature electrochemical devices for direct conversion of fuel and oxidant to electricity and heat. The high temperature and dual atmosphere creates challenges for the materials in solid oxide fuel cell stacks. In this thesis SOFC stack materials were studied and developed. SOFC stacks are assembled at room temperature, then heated up, conditioned and operated...

Downward propagation of a combustion front in a packed bed of wood particles, with air supply from below, is examined theoretically and experimentally. Using a single-step reaction, with a kinetic model of char oxidation as the dominant mechanism, and assuming local thermal equilibrium, but allowing a local chemical nonequilibrium between the solid and gas phases, the front speed u F, the adiab...

Inconel and micro nano WC-12Co powders were deposited on AISI 4140 carbon steel by high-velocity oxy fuel (HVOF) coating followed laser surface modification. Laser power scan speed varied at different levels. Microstructure microhardness investigated. Nanocoatings performed better than microcoatings. Nanostructured WC powder coatings exhibited greater hardness compared to microstructured coatin...

Abstract Driven by the search for an optimum combination of particle velocity and process temperature to achieve dense hard metal coatings at high deposition efficiencies powder feed rates, high-velocity air-fuel spraying (HVAF) was developed. In terms achievable velocities temperatures, this can be classified between oxy-fuel (HVOF) cold gas (CGS). The particular advantages HVAF regarding mode...

Rare earth elements have been widely utilized in material manufacturing to enhance properties various ways. In order obtain the WC-10Co4Cr coating with uniform distribution of rare earths, CeO2-modified powder was prepared by mixing 1 wt.% nano-sized CeO2 during initial ball-milling fabrication process. Bare and coatings were deposited via high velocity oxygen fuel spraying investigate impact m...

In this work, result of experimental investigation on interaction of fuel spray generated by a swirled type injector, with air motion in a prototype cylinder are presented. Experiments were carried out by planar imaging and particle image velocimetry (PIV) techniques in order to provide information about the spray structure evolution and instantaneous velocity distribution of air motion and ...

In recent decades, fuel cells have been widely used in energy generation. In a PEMFC, considering the specific application, two types of oxidants are used. Durability tests, which are highly costly products,  are of crucial importance in evaluating the lifetime of fuel cells. The purpose of the present paper is to investigate the performance of a fuel cell by changing the type of oxidant from a...