The electricity generation process from fossil fuels is one of the sources of CO${}_2$ emissions. The post-combustion CO${}_2$ capture is an alternative to minimize emissions. The packed absorption column is the first unit of the CO${}_2$ capture process. In this study, the values of the process parameters were established to reduce the absorber-packed height using a simulator developed in this work. The simulator was validated using measurements in a laboratory-scale absorption unit; simulations were carried out with the same operating conditions as measurements and two different fuels were treated; coal and natural gas. A combined-cycle power plant in Mexico was simulated, with the objective of evaluating the main parameters in the absorption process and required dimensions of the packed absorption column required to carry out the capture of CO${}_2$ in the power plant. From the result of the simulations, three columns treatment with 3 m diameter and 7 m height were established to remove 99% of the CO${}_2$ of the flue gases with 20 wt.% of MEA composition using Mellapak 500Y structured packaging.

With the aim of improving the performance of vertical axis wind turbines, in this article, the flow field and aerodynamic performance of an H-rotor Darrieus turbine are computed using computational fluid dynamics. Specifically, the power coefficient (Cp) of different airfoil profile thicknesses was evaluated as a function of tip-speed ratios (TSRs) and wind speed. Four different thicknesses of the NREL S815 airfoil were evaluated, and the TSR was varied from 0.6 to 2.25 using wind speeds of 6 and 8 m/s. As a result, the power coefficient (Cp) was calculated for each airfoil and the different tip-speed ratios. It was found that for each airfoil profile, the Cp increases when the airfoil thickness and the TSR rise, until reaching a maximum, then the Cp decreases in spite of larger thickness or TSRs. After comparing the performance of each airfoil profile, the Cp is improved 14.96% for 19.2% thicker airfoils, using a TSR of 1.725 and a wind speed of 8 m/s.

Flow Measurement Methods Applied to Hydro Power Plants | InTechOpen, Published on: 2012-03-28. Authors: Gustavo Urquiza, Miguel A. Basurto, Laura Castro, et