Direct energy conversion of heat to electricity using AMTEC
Former renewable technologies, which did not prosper at that time due to engineering and material limitations, emerge once again, as in the case of the Alkali Metal Thermal to Electric Converter (AMTEC). This energy converter transforms heat to electricity through an electrochemical process at high temperature (700 - 1000 °C). At Karlsruhe Institute of Technology (KIT) an AMTEC test cell and an AMTEC TEst FAcility (ATEFA) have been designed and are under construction. The paper gives an overview of the history of AMTEC converter and its development; and presents the ATEFA facility included its latest progress in design and construction. In addition, a scoping study on the stability of PEEK polymer compound in liquid sodium environment was started and is reported.
The breakdown of β-alumina ceramic electrolyte
Abstract The “breakdown” of β-alumina ceramic electrolyte under continuous electrolysis at 300°C has been shown to involve the formation of molten sodium dendrites. A mechanism of propagation of these dendrites, based on the extension of extant micro-cracks due to the Poiseuille pressure, is suggested.
EFFECT OF SAMPLE PREPARATION ON WATER TREE RESISTANCE OF XLPE/SEBS BLENDS
The effects of an aromatic polymer, such as poly[styrene-b-(ethylene-co-butylene)b-styrene] (SEBS), and its preparation processes on water tree resistance, morphology, crystallinity, dielectric constant and dielectric loss tangent of crosslinked polyethylene (XLPE)/SEBS and XLPE/SEBS/ethylene vinyl acetate (EVA) blends were investigated. The XLPE/SEBS samples were characterized by means of differential scanning calorimetry, scanning electron microscopy, dielectric spectral analysis and the accelerated water treeing experiment. The results clearly showed that although SEBS was partially compatible with LDPE and it was dispersed evenly in XLPE matrix, the blends demonstrated excellent dielectric performances, such as dielectric constant and dissipation factor. The crystallinity of XLPE/SEBS blends was decreased with increase in SEBS content and it was further decreased with the addition of EVA. SEBS could effectively improve the water-tree resistance of XLPE and both SEBS and EVA were found to improve the water tree resistance of XLPE synergistically as expected. The differences in sample preparation processes could change the phase morphology and dielectric performance of the blends, and could also influence the dispersion of SEBS in XLPE matrix as well as the crystallinity of the blends. Different preparation processes led to different water tree resistance behaviours of the samples. The improvement of SEBS dispersion in XLPE matrix helped to improve the water tree resistance of XLPE.