Moving granular-bed filter development program - option 1 - component test facilities

The Westinghouse Science & Technology Center has proposed a novel moving granular bed filter concept, the Standleg Moving Granular Bed Filter (SMGBF). The SMGBF has inherent advantages over the current state-of-the-art moving granular bed filter technology and is potentially competitive with ceramic barrier filters. The SMGBF system combines several unique features that make it highly effective for use in advanced coal-fueled power plants, such as pressurized fluidized-bed combustion (PFBC), and integrated coal-gasification combined cycles (IGCC). The SMGBF is being developed in a phased program having an initial Base Contract period followed by optional periods. The Base Contract period was successfully completed and previously documented by Westinghouse. The Option 1 period, {open_quote}Component Test Facilities{close_quotes}, has also been completed and its results are reported in this document. The objective of the Option 1 program was to optimize the performance of the SMGBF system through component testing focused on the major technology issues. The SMGBF has been shown to be a viable technology in both cold flow simulations and high-temperature, high-pressure testing, and conditions to lead to best performance levels have been identified. Several development activities remain to be complete before the SMGBF can achieve commercial readiness

Westinghouse Advanced Particle Filter System

Integrated Gasification Combined Cycles (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) are being developed and demonstrated for commercial, power generation application. Hot gas particulate filters are key components for the successful implementation of IGCC and PFBC in power generation gas turbine cycles. The objective of this work is to develop and qualify through analysis and testing a practical hot gas ceramic barrier filter system that meets the performance and operational requirements of PFBC and IGCC systems. This paper reports on the development and status of testing of the Westinghouse Advanced Hot Gas Particle Filter (W-APF) including: W-APF integrated operation with the American Electric Power, 70 MW PFBC clean coal facility--approximately 6000 test hours completed; approximately 2500 hours of testing at the Hans Ahlstrom 10 MW PCFB facility located in Karhula, Finland; over 700 hours of operation at the Foster Wheeler 2 MW 2nd generation PFBC facility located in Livingston, New Jersey; status of Westinghouse HGF supply for the DOE Southern Company Services Power System Development Facility (PSDF) located in Wilsonville, Alabama; the status of the Westinghouse development and testing of HGF`s for Biomass Power Generation; and the status of the design and supply of the HGF unit for the 95 MW Pinon Pine IGCC Clean Coal Demonstration

Real-space local polynomial basis for solid-state electronic-structure calculations: A finite-element approach

We present an approach to solid-state electronic-structure calculations based on the finite-element method. In this method, the basis functions are strictly local, piecewise polynomials. Because the basis is composed of polynomials, the method is completely general and its convergence can be controlled systematically. Because the basis functions are strictly local in real space, the method allows for variable resolution in real space; produces sparse, structured matrices, enabling the effective use of iterative solution methods; and is well suited to parallel implementation. The method thus combines the significant advantages of both real-space-grid and basis-oriented approaches and so promises to be particularly well suited for large, accurate ab initio calculations. We develop the theory of our approach in detail, discuss advantages and disadvantages, and report initial results, including the first fully three-dimensional electronic band structures calculated by the method.Comment: replacement: single spaced, included figures, added journal referenc

Gas Turbine Reheat Using In-Situ Combustion

Siemens Westinghouse Power Corporation (SWPC) is developing in-situ reheat (fuel injection via airfoil injection) as a means for increasing cycle efficiency and power output, with possibly reduced emissions. This report discusses engineering cycle evaluations on various reheat approaches, using GateCycle and ChemCad software simulations of typical F-class and G-class engines, modified for alternative reheat cycles. The conclusion that vane 1 reheat offers the most advantageous design agrees with the conclusions of the detailed chemical kinetics (Task 2) as verified by high temperature testing (Task 3) and Blade path CFD (Task 1) tasks. The second choice design option (vane 2 reheat after vane 1 reheat) is also validated in all tasks. A conceptual design and next recommended development tasks are presented

Gas Turbine Reheat Using in Situ Combustion: Final Report, Draft

In situ reheat is an alternative to traditional gas turbine reheat design in which fuel is fed through airfoils rather than in a bulky discrete combustor separating HP and LP turbines. The goals are to achieve increased power output and/or efficiency without higher emissions. In this program the scientific basis for achieving burnout with low emissions has been explored. In Task 1, Blade Path Aerodynamics, design options were evaluated using CFD in terms of burnout, increase of power output, and possible hot streaking. It was concluded that Vane 1 injection in a conventional 4-stage turbine was preferred. Vane 2 injection after vane 1 injection was possible, but of marginal benefit. In Task 2, Combustion and Emissions, detailed chemical kinetics modeling, validated by Task 3, Sub-Scale Testing, experiments, resulted in the same conclusions, with the added conclusion that some increase in emissions was expected. In Task 4, Conceptual Design and Development Plan, Siemens Westinghouse power cycle analysis software was used to evaluate alternative in situ reheat design options. Only single stage reheat, via vane 1, was found to have merit, consistent with prior Tasks. Unifying the results of all the tasks, a conceptual design for single stage reheat utilizing 24 holes, 1.8 mm diameter, at the trailing edge of vane 1 is presented. A development plan is presented

Estimating evolutionary distances from spaced-word matches

International audienceAlignment-free methods are increasingly used to estimate distances between DNA and protein sequences and to reconstruct phylogenetic trees. Most distance functions used by these methods, however, are heuristic measures of dissimilarity, not based on any explicit model of evolution. Herein, we propose a simple estimator of the evolutionary distance between two DNA sequences calculated from the number of (spaced) word matches between them. We show that this distance function estimates the evolutionary distance between DNA sequences more accurately than other distance measures used by alignment-free methods. In addition, we calculate the variance of the number of (spaced) word matches depending on sequence length and mismatch probability