Water-Cooled Gas Turbine Technology Development: Fuels Flexibility

Abstract

A continuing technology development program initiated by General Electric (GE) in the early 1960s and joined by the Electric Power Research Institute (EPRI) in 1974 is successfully resolving potential barrier problems in the development of water cooled turbines. Early work by GE Corporate Research and Development demonstrated the feasibility of closed circuit, pressurized water-cooling of stationary nozzles (vanes), and of open circuit, unpressurized water-cooling of rotating buckets (blades). A small-scale turbine was designed, fabricated, and operated at a gas temperature of 2850 F (1565 C) at 16 atm, with surface metal temperatures less than 1000 F (540 C). Early results from the EPRI sponsored Water-Cooled Gas Turbine Development Programs were presented at the 1978 Gas Turbine Conference (Report #ASME 78-GT-72). This paper reports more recent results, obtained between mid-1977 and mid-1978. Significant progress has been made in a number of areas: (a) water-cooled nozzle and bucket design and fabrication, (b) corrosion kinetics model verification and testing, (c) partially filled internal channel bucket heat transfer testing, and (d) stationary to rotating water transfer and collection testing. Results to date are encouraging with regard to the application of water-cooled turbine components to achieve improved reliability and fuels flexibility at increased turbine firing temperatures.

Prediction of Film Cooling Effectiveness of Steam

“…An alternate cooling method developed by General Electric Company, Electric Power Research Institute, and the Dpeartment of Energy for the combined gas/ steam cycle is the water-cooling technique [8][9][10][11][12]. The vanes (nozzles) are cooled internally by forced convection using a high pressure, closed-loop system.…”

Water-Cooled Gas Turbine Nozzle Technology Demonstration at Ultra-High Firing Temperature

“…Advantages of water cooling have been presented by Caruvana et al [1] and Horner et al [4). With the use of low-Btu coal gas, where almost all of the compressor air is required for the coal gasification and combustion, water cooling hot gas path hardware allows the use of the limited excess air for combustor cooling.…”

“…Moreover, with low-grade fuels, the concern of plugging film-cooling holes is avoided. The inherent low surface temperature of water-cooled hardware reduces Copyright © 1983 by ASME oxidation/hot corrosion and eases ash removal, as discussed by Horner et al [4,5] and Rose et al [6].…”

Testing and Evaluation of a Water-Cooled Gas Turbine Nozzle

“…This paper describes the final testing and evaluation of these nozzles. Further background information concerning the combined-cycle gas turbine design and the definition of the program has also been previously reported [3][4][5][6][7][8][9].…”