Composition of initial mixtures for production of the gaseous CHO fuel for fuel cells with molten alkaline carbonates

ENERGYCONVERSION Summaries for Card Indexes J. M. WU and D. T. SHAW, State University of New York at Buffalo, Buffalo, New York. Forbidden line intensities in c&urn plasmas: Energy Conversion 12, 77-80 (1972). Summary-Profiles of 6G-5D (Al = 2) forbidden line transitions in cesium plasmas have been investigated both theoretically and experimentally. The calculations have been carried out based on a model which assumes the quasi-static approximation for the ion broadening effect and impact approximation for the electron effect. A 0.5 m scanning monochromator is used to measure line shapes and intensities from a cesium thermionic diode operated in the ignited mode. The electron densities are determined from the half-width of the nF-SD lines and the relative continuum radiations from 4000 to 5OOOA are used to determine the temperatures. The experimental data range in electron densities from 7.5 x 10’3 to 6 x 1014cm-3 and temperatures from 2000 to 35OO”K, while the theoretical calculations range from 1013 to 1.6 x 1015cm-3 for densities and 2000-6000°K for temperatures. It is shown that the relative line intensities ratio of 6G-5D transition to 6F-5D transition is found to be proportional to n, 1.2. This is valid for electron densities below 4 x 1014cm-3 and almost temperature independent from 2000 to 6000°K. The possible use of the forbidden line intensities for diagnostic purpose is discussed. Key words: cesium plasma

measurement

forbidden thermionic diode

D. J. CURTIN and A. MEULENBERG,

transition

electron density

COMSAT Laboratories,

spectroscopic

Clarksburg, Maryland.

One MeV electron irradiation of new technology silicon solar cells: Energy Conversion 12, 81-84 (1972). Summary-Silicon solar cells were irradiated with 1 MeV electrons using a Van de Graaff accelerator. Covered cells with TiOz anti-reflective coatings had higher electrical performance before and after irradiation than cells from the same ingot covered with SiOz anti-reflective coatings. High efficiency experimental p-on-n and n-on-p cells were tested and compared to standard cells of the same types. The initial degradation rate of the high efficiency fz-on-p cells was greater than that of the standard cells, but the efficiencyfluence curves for both groups merged after exposure to 3 x 10’4 1 MeV electrons/cmz. In the case of the p-on-n cells, merging of the curves did not occur even at a fluence of lo16 electrons/cm2. Key words: one MeV electron irradiation silicon solar cells TiOz anti-reflective N-on-P cells P-on-N cells coatings SiOz anti-reflective coatings gettering E. CLEMBRONOWICZ, L. SUSKI and Z. KUBAS, School of Mining and Metallurgy, Institute of Metallurgy, Department of Physical Chemistry, Cracow, Poland. Composition of initial mixtures for production of the gaseous C-H-O molten alkaline carbonates: Energy Conversion 12, 85-88 (1972).

fuel for fuel cells with

Summary-The compositions of binary mixtures of aliphatic alcohol or gaseous paraffin and water and of ternary mixtures of aliphatic alcohol or paraffin, water and carbon dioxide, applicable in production of the gaseous C-H-O fuels for high-temperature fuel cells, are given. As criteria for the choice of these compositions the non-intersecting of the oxidation path of the C-H-O fuel, corresponding to the carbon deposition isotherms, with these isotherms at the lowest possible operating temperature, have been assumed. For binary mixtures these lowest temperatures and the corresponding to them molar ratios of the initial components have been determined. For ternary mixtures the molar ratios of the initial components corresponding to the temperatures close to melting points of binary and ternary eutectic mixtures of Li, Na and K carbonates have been given. Key words: fuel cells equilibria in gaseous fuels

molten alkaline carbonates electrode oxidation of fuels

fuel carbond ecomposition high-temperature fuel cells

E. MAIER, Institut fiir Kemenergetik, Universitgt Stuttgart, 7000 Stuttgart-80, Pfaffenwaldring 3 1, Germany. Bestimmung des Austrittspotentials ciisiumhedeekter Ober&chen bei hohen Temperaturen mit einer planparallelen Ctisium-Diode-I. Technologie: Energy Conversion 12, 89-93 (1972). Snmmary-Design and construction of a thermionic cesium diode with plane-parallel electrodes is presented. The diode is used for measuring the work function of various emitter materials under diode operating conditions. The spacing between the exchangeable electrodes is variable and the electrodes themselves are adjustable to obtain and maintain the parallel geometry. The temperature of the tantalum emitter is measured pyrometrically through a sapphire window in a ‘black body’ hole of the emitter. The collector is surrounded by an electrically insulated guardring with separate electrical circuit. Collector and guardring are watercooled and additionally electrically heated. Thermocouples are used for measuring collector and guardring temperatures. Primary operation of the diode was successful. Measurements were carried out in the unignited and ignited mode at emitter temperatures between 1630 and 1900°K and cesium vapor pressures between 0.5 and 6 torr. The maximum electrical power output density was 4.2 W/cmZ. cesium covered surfaces Key words: work function electron-beam-welding energy conversion refractory metals high-temperature brazing thermionic diode i 8