Alternative combustion turbine designs and cleanup systems for pressurized fluidized-bed combustion (PFBC) power plants: Final report

This report explores effects of alternative gas cleanup systems and utility combustion turbine designs on costs and turbine erosion, deposition and corrosion tolerances for pressurized fluidized bed combustion (PFBC) power plants. The first type of turbine design variation involves ruggedization to increase expander tolerances to the degrading tendencies of PFBC expansion gases which contain particulate and chemical contaminants. The second type of variation involves turbine design to permit expansion of PFB combustion gases below 1000/sup 0/F. Such turbine designs would be applied to PFBC turbocharged boilers. Utilizing these turbine designs, three specific turbine/power plant configurations operating with alternative gas cleanup systems are evaluated and compared. One plant configuration utilizes an existing conventional utility turbine; the second utilizes a ruggedized version of that machine; the third uses a turbine specially modified for the PFBC turbocharged boiler. The alternative gas cleanup systems involve proven cyclones and advanced ceramic bag and candle filter devices currently being developed. Since ruggedized and low temperature utility turbines do not currently exist, specific flow path designs for these turbines matched to the specified power plant configurations were obtained in this work. To minimize the cost of providing ruggedized and low temperature turbines for PFBC power plant applications,more » the machines identified for evaluations are modified versions of existing turbines. Using the expander flowpath descriptions, maintenance intervals and corrosion potential were estimated and compared for all three turbines operating with their respective power plants and alternative gas cleanup systems. Turbine and gas cleanup equipment costs are also estimated and compared for the three PFBC power plant configurations. 14 refs., 14 figs., 17 tabs.« less