An Ultra High Temperature Turbine for Maximum Performance and Fuels Flexibility

Abstract

The problems in water-cooled rotors have centered around the high pressuies generated in a closed circuit containing water by the high centrifugal field. The present program focusses on open circuit water cooling in which the water has been allowed to exit freely from the bucket tips. This eliminates the leaks and plugging of cooling channels that have been encountered before permits one to distribute the coolant uniformly around the bucket airfoil contour close to the surface. In this way the thermal gradients and thermal stresses on the airfoil can be held within safe limits. Using this approach a 9.7 in. (24.7 cm) diameter turbine wheel has been built and operated at inlet conditions of 2850 F (1560 C) and 16 atmosphere with tip speeds in excess of 1700 fps (518 m/sec) and with good aerodynamic efficiency. Recent developments in ceramic materials also indicate potential for use in stationary parts.

Two-Phase Microchannel Heat Sinks: Theory, Applications, and Limitations

“…During the 1970s, the U.S. Department of Energy (DOE) initiated an aggressive high-temperature turbine program that was aimed at exploiting the merits of water cooling the turbine blades. Much of this program was based on a study by General Electric Company [20,21] that promised significant power plant combined-cycle efficiency improvements by increasing the firing temperature to 1650 C. Aside from the efficiency improvements, a key goal was to enable the utilization of coal-derived and residual petroleum fuels. These initial studies pointed to a need to greatly decrease turbine blade temperatures in order to prevent hot corrosion effects in such a highly corrosive environment.…”

“…These initial studies pointed to a need to greatly decrease turbine blade temperatures in order to prevent hot corrosion effects in such a highly corrosive environment. Hot corrosion could be largely prevented if the blade surface temperature is maintained below 540 C. Since air film and transpiration cooling techniques cannot maintain blade surface temperature in industrial turbines below 870 C, only water cooling was deemed effective at achieving the 540 C limit [20,21].…”

“…# À1 (20) in order to predict two-phase pressure drop. The SFMs involve determining the accelerational and frictional components of pressure drop independently.…”

Water-Cooled Gas Turbine Technology Development: Fuels Flexibility

“…Water cooling of commercial heavy-duty gas turbine hot section components offers a number of potential advantages over air cooling: (a) cycle performance will be improved because turbines can be operated at higher firing temperatures and pressure levels, (2) reliability will be increased because of the reduction in component metal temperatures, and (c) heavy or contaminated fuels will be accommodated because cooling holes (which are prone to plugging) will be eliminated and because the low surface metal temperatures decrease the corrosion rate and the ash deposition rate. Significant progress has already been made in the development of the technology necessary to commercialize water cooling (1)(2)(3)(4)(5). 1 This paper presents the results obtained from the continuation of the GE/EPRI Water-Cooled Gas Turbine Development program and other related parallel programs since the publication of the last report, in April of 1978 (2).…”

“…Significant progress has already been made in the development of the technology necessary to commercialize water cooling (1)(2)(3)(4)(5). 1 This paper presents the results obtained from the continuation of the GE/EPRI Water-Cooled Gas Turbine Development program and other related parallel programs since the publication of the last report, in April of 1978 (2).…”