ABSTRACT
High-flux solar simulators consist of lamps that mimic concentrated sunlight from a field of heliostats or parabolic dish. These installations are used to test promising solar-thermal technologies for commercial potential. Solar simulators can be calibrated with cylindrical calorimeters, devices that approximate black body absorbers. Calorimeter accuracy is crucial to solar simulator characterization and maintenance. To discover the worst-case performance of a cylindrical calorimeter during flux measurement Monte Carlo ray tracing was coupled to finite volume simulations. Results indicated that the calorimeter can exhibit an observer effect that distorts the solar simulator flux profile. Furthermore, the proposed design was sensitive to changes in calorimeter optical properties, changes that can result from oxidation and/or photobleaching over time. Design fidelity and robustness were substantially improved through the use of a beveled (conical) calorimeter aperture.
ABSTRACT
High temperature steam gasification/reforming of biomass-methane mixtures was carried out in an indirectly heated entrained flow reactor to analyze the feasibility of controlling the output composition of the major synthesis gas products: H(2), CO, CO(2), CH(4). A 2(3) factorial experimental design was carried out and compared to thermodynamic equilibrium predictions. Experiments demonstrated the product gas composition is mostly dependent on temperature and that excess steam contributes to CO(2) formation. Results showed that with two carbon-containing reactants it is possible to control the gas composition of the major products. At 1500 °C, the equilibrium results accurately predicted the syngas composition and can be used to guide optimization of the syngas for downstream liquid fuel synthesis technologies.
