Ruhrchemie/Ruhrkohle’s Technical Version of the Texaco Coal Gasifier as Part of a Combined Cycle Plant

The Ruhrchemie/Ruhrkohle variant of the Texaco Coal Gasification Process (TCGP) has been on stream since 1978. As the first demonstration plant of the “second generation” it has confirmed the advantages of the simultaneous gasification of coal: at higher temperatures; under elevated pressures; using finely divided coal; feeding the coal as a slurry in water. The operating time so far totals 9000 hrs. More than 50,000 tons of coal have been converted to syn gas with a typical composition of 55 percent CO, 33 percent H2, 11 percent CO2 and 0.01 percent of methane. The advantages of the process — low environmental impact, additional high pressure steam production, gas generation at high pressure levels, steady state operation, relatively low investment costs, rapid and reliable turn-down and load-following characteristics — make such entrained-bed coal gasification processes highly suitable for power generation, especially as the first step of combined cycle power plants.

Erosion Resistance and Efficiency of Energy Exchangers

Applications of energy exchangers, a type of gasdynamic wave machine, were evaluated in power plants fired by pressurized, fluidized bed combustors (PFBCs). Comparative analyses of overall power plant efficiency indicate that the use of energy exchangers as hot gas expanders may provide a 0.5 to 1.5 efficiency point increase relative to gas turbines. In addition, the unique operating characteristics of these machines are expected to reduce rotating component wear by a factor of 50 to 300 relative to conventional gas turbines operating in the particulate laden PFBC effluent stream.

High-Temperature Turbine Technology Readiness

Final component and technology verification tests have been completed for application to a 2600°F rotor inlet temperature gas turbine. These tests have proven the capability of combustor, turbine hot section, and IGCC fuel systems and controls to operate in a combined cycle plant burning a coal-derived gas fuel at elevated gas turbine inlet temperatures (2600–3000°F). This paper presents recent test results and summarizes the overall progress made during the DOE-HTTT Phase II program.

Atomization Quality of Twin Fluid Atomizers for Gas Turbines

A detailed investigation of the effect of nozzle/needle diameter ratio, normal fuel area, swirler degree, air pressure, fuel pressure on flow number, cone angle and droplet size distribution of external mixing twin fluid atomizers is given in this paper. Forty atomizers have been constructed to prevent mutual effect of various parameters. Flow number and cone angle are found to increase with nozzle/diameter ratio, and to decrease with the increase of air pressure. Optimum fuel flow is obtained at swirler angle 30-deg, while cone angle increases with increase of swirler angle. Sauter mean diameter decreases with the increase of air pressure and decrease of fuel pressure. Suitable functions are derived for droplet size distribution, Sauter mean diameter, and flow number. They are suitable to predict the geometry of the atomizer and to be used also in a prediction model for the calculation of fuel concentration and heat release.

Particulate and Sulfur Oxides Emissions From a 60-MW Heavy Duty Gas Turbine Burning No. 2 Distillate Fuel: Methods Development and Test Results

A method for the measurement of particulate and sulfur oxides emissions has been developed and tested in the laboratory and the field. The development shows that changes in analysis methods, procedures, and materials are necessary in order to adapt standard USEPA methods to gas turbine conditions. In particular, extreme care must be taken to prevent the formation of pseudo particulate from sulfur dioxide. The field results demonstrate that a G.E. MS7001B emits less than 10 lbm/hr of total particulate if the fuel ash and sulfur content are suitably restricted.

The Potential Impact of Future Fuels on Small Gas Turbine Engines

The impact of potential aviation gas turbine fuels available in the near to midterm, is reviewed with particular reference to the small aviation gas turbine engine. The future course of gas turbine combustion R&D, and the probable need for compromise in fuels and engine technology, is also discussed. Operating experience to date on Pratt & Whitney Aircraft of Canada PT6 engines, with fuels not currently considered of aviation quality, is reported.

Dust Removal Concepts for Pressurized Fluidized Bed Systems

Improved high-temperature (1700°F, 925°C) dust removal concepts are being developed for pressurized fluidized bed combined cycle power generation. Recent results on cyclones, electrocyclones, an acoustic agglomerator, a ceramic bag filter, and an electrostatic granular bed filter are reviewed. The development status of each device is described, and the relative merits of each concept are discussed. System designs for employing each of the dust removal concepts in a 650 MWe PFB reference plant are presented in order to illustrate the application of the devices, and approximate economic comparisons are made for this application.

Comparative Performance Study of Closed Cycle Gas Turbine Utilizing Cryogenic Cold

The re-evaporation of Liquefied Natural Gas (LNG) is capable of acting as a low temperature heat sink for power cycles, thereby enhancing the thermal efficiency of the cycle. Leaving aside the detail of the appropriate heat exchanger technology, the comparative performance of improved high and low temperature closed cycle gas turbines is investigated using non-dimensionalized performance analysis. It was shown that the effect of lowering the minimum cycle temperature on the efficiency is equivalent to raising the maximum cycle temperature by a multiple amount. The specific output, however, decreases to a fraction of that achieved by the cycle with the original minimum cycle temperature. Implications are drawn for the application of the closed cycle gas turbine utilizing cryogenic cold.

Design of a 6- by 6-Foot Coal-Fired Heater for a CCGT Air Heater

The U.S. Department of Energy is sponsoring a program of research and development on coal-fired heaters to provide heat input to the working fluid of a closed-cycle gas turbine/cogeneration system. One of the fired heater concepts being researched employs the atmospheric pressure fluidized bed coal combustion concept. This paper describes a research oriented atmospheric fluidized bed of 6- by 6-foot plan dimensions that has been designed and is being constructed for utilization during the R&D program. The design rationale is presented, details of the more significant details are described and discussed, and the planned methods for utilizing the 6- by 6-foot AFB as a research tool are presented.

Acoustic Control of Dilution-Air Mixing in a Gas Turbine Combustor

A small combustor of normal design employing acoustic control of the dilution-air flows has been successfully tested up to “half-load” conditions. It has been shown that this technique can be used to selectively and progressively control the exit plane temperature distribution, and the ability to trim the temperature profile has been convincingly demonstrated. The acoustic driver power requirements were minimal indicating that driver power at “full-load” will not be excessive. The nature of the acoustically modulated dilution-air flows has been clearly establish to the design of combustors such that a desired exit plane temperature distribution may be achieved.