Thomas E. Lippert

Status of Westinghouse Hot Gas Filters for Coal and Biomass Power Systems

Several advanced, coal and biomass-based combustion turbine power generation technologies using solid fuels (IGCC, PFBC, Topping-PFBC, HIPPS) are currently under development and demonstration. A key developing technology in these power generation systems is the hot gas filter. These power generation technologies must utilize highly reliable and efficient hot gas filter systems iftheir full thermal efficiency and cost potential is to be realized. This paper reviews the recent test and design progress made by Westinghouse in the development and demonstration of hot gas ceramic barrier filters toward the goal of reliability. The objective of this work is to develop and qualify, through analysis and testing, practical hot gas ceramic barrier filter systems that meet the performance and operational requirements for these applications.

The Influence of In Situ Reheat on Turbine-Combustor Performance

This paper presents a numerical and experimental investigation of the in situ reheat necessary for the development of a turbine-combustor. The flow and combustion were modeled by the Reynolds-averaged Navier-Stokes equations coupled with the species conservation equations. The chemistry model used herein was a two-step, global, finite rate combustion model for methane and combustion gases. A numerical simulation was used to investigate the validity of the combustion model by comparing the numerical results against experimental data obtained for an isolated vane with fuel injection at its trailing edge. The numerical investigation was then used to explore the unsteady transport phenomena in a four-stage turbine-combustor. In situ reheat simulations investigated the influence of various fuel injection parameters on power increase, airfoil temperature variation, and turbine blade loading. The in situ reheat decreased the power of the first stage, but increased more the power of the following stages, such that the power of the turbine increased between 2.8% and 5.1%, depending on the parameters of the fuel injection. The largest blade excitation in the turbine-combustor corresponded to the fourth-stage rotor, with or without combustion. In all cases analyzed, the highest excitation corresponded to the first blade passing frequency.

Cold flow studies of a novel fluidized bed emissions clean-up concept

Abstract Cold flow studies were performed as part of the U.S. Department of Energy Direct Coal-Fired Turbines development program to demonstrate the conceptual feasibility of a fluidized bed contactor containing immersed ceramic candle filters for particle removal, as well as for alkali and sulfur removal. The fluidized bed cold flow unit is constructed of a 25.4-cm transparent Plexiglas pipe, 1.7 m high. Three different arrangements of ceramic candle filters, each 6 cm O.D. by 1 m long, were immersed in the fluidized bed to different depths. Design (filter element design and arrangement) and operating parameters (fluidizing velocity, bed height, dust concentration in the bed, depth of filter immersion in the bed) were changed during the tests. A mathematical model was developed to elucidate the phenomena. The tests have produced preliminary design and operating criteria for the concept, and operability concerns have been identified.

Westinghouse Status of Coal and Biomass Fueled Combustion Turbine Systems for Power Generation

Coal and biomass are of interest today as alternatives to conventional combustion turbine fuels. Significant processing is required for these fuels to be used in combustion turbine applications. Westinghouse is developing and demonstrating technologies for fuel processing, hot gas cleaning, and fuel gas combustion, and is assessing combustion turbine adaptations for coal and biomass fuels. This paper reviews the status of Westinghouse development and demonstration activities for the use of coal and biomass fuels in advanced power generation systems incorporating combustion turbines for pressurized fluidized bed combustion (PFBC), integrated gasification combined cycles (IGCC), and direct coal-fired (DCF) cycle configurations.Copyright

Development of Hot Gas Cleaning Systems for Advanced, Coal Based Gas Turbine Cycles

Westinghouse is developing hot gas cleaning systems for advanced, coal based gas turbine cycles. This paper summarizes the Westinghouse hot gas filter concept and reports on recent in-house and field test programs supporting its design and development. Basic materials issues related to ceramic material stability and hot metals structures are reviewed. Results of recent filter system testing are presented comparing candle and cross flow designs operating in both “simulated” and actual coal derived gas streams. Laboratory tests and analysis are reported relating to integrating sulfur and alkali control with the particle filter function.© 1992 ASME

ANALYSIS OF UNSTEADY AEROTHERMODYNAMIC EFFECTS IN A TURBINE-COMBUSTOR

This paper presents a numerical investigation of the unsteady transport phenomena in a turbine-combustor. The flow and combustion are modeled by the Reynolds-averaged Navier-Stokes equations coupled with the species conservation equations. The chemistry model used herein is a two-step, global, finite rate combustion model for methane and combustion gases. The governing equations are written in the strong conservation form and solved using a fully implicit, finite difference approximation. This numerical algorithm has been used to investigate the airfoil temperature variation and the unsteady blade loading in a four-stage turbine-combustor. The numerical simulations indicated that in situ reheat increased the turbine power by up to 5.1%. The turbine combustion also increased blade temperature and unsteady blade loading. Neither the temperature increase nor the blade loading increase exceeded acceptable values for the turbine investigated.

Development and Commercialization of Hot Gas Filters for Power Generation Applications

Westinghouse is conducting a broad development program under US Department of Energy (DOE) and corporate program initiatives to commercialize hot gas filtration (HGF) for power generation. Coal and biomass gasification combined cycles (GCC), and Pressurized Fluidized Bed Combustion (PFBC) are advanced power generation cycles that will use HGF to achieve maximum performance. Westinghouse, in conjunction with DOE are participating in several pilot and demonstration test programs in which hot gas filter systems are integrated and operated in coal derived gas streams. This paper reports on HGF testing conducted over the past year in the following pilot plant facilities: At the PFBC Hot Gas Clean Slipstream facility installed at the Tidd 70-MWe bubbling-PFBC Clean Coal Demonstration Plant; at the Ahlstrom 10 Mwt Circulating-PFBC facility located in Karhula, Finland; at the Advanced-PFBC subpilot facility located at the Foster Wheeler Development Corporation Livingston, NJ site; at the Biomass subpilot gasification facility located at the Institute of Gas Technology (IGT). Test results include operating experience on both conventional and advanced candle filter elements.