Collaborative Advanced Gas Turbine Program: Phase 1. Final report

This report summarizes work performed by Garrett Auxiliary Power Division (GAPD), a unit of Allied-Signal Aerospace Company, during calendar year 1992, toward development and demonstration of structural ceramic technology for automotive gas turbine engines. This work was performed for the US Department of Energy (DOE) under National Aeronautics and Space Administration (NASA) Contract DEN3-335, Advanced Turbine Technology Applications Project (ATTAP). GAPD utilized the AGT101 regenerated gas turbine engine developed under the previous DOE/NASA Advanced Gas Turbine (AGT) program as the ATTAP test bed for ceramic engine technology demonstration. ATTAP focussed on improving AGT101 test bed reliability, development of ceramic design methodologies, and improvement of fabrication and materials processing technology by domestic US ceramics fabricators. A series of durability tests was conducted to verify technology advancements. This is the fifth in a series of technical summary reports published annually over the course of the five-year contract.

Interest in hydrogen as a primary fuel stream in heavy-duty gas turbine engines has increased as precombustion carbon capture and sequestration (CCS) has become a viable option for integrated gasification combined cycle (IGCC) power plants. The U.S. Department of Energy has funded the Advanced IGCC/Hydrogen Gas Turbine Program since 2005 with an aggressive plant-level NOx target of 2 ppm at 15% O2 for an advanced gas turbine cycle. Approaching this NOx level with highly reactive hydrogen fuel at the conditions required is a formidable challenge that requires novel combustion technology. This study begins by measuring entitlement NOx emissions from perfectly premixed combustion of the high-hydrogen fuels of interest. A new premixing fuel injector for high-hydrogen fuels was designed to balance reliable flashback-free operation, reasonable pressure drop, and low emissions. The concept relies on small-scale jet-in-crossflow mixing that is a departure from traditional swirl-based premixing concepts. Single nozzle rig experiments were conducted at pressures of 10 atm and 17 atm, with air preheat temperatures of about 650 K. With nitrogen-diluted hydrogen fuel, characteristic of carbon-free syngas, stable operation without flashback was conducted up to flame temperatures of approximately 1850 K. In addition to the effects of pressure, the impacts of nitrogen dilution levels and amounts of minor constituents in the fuel—carbon monoxide, carbon dioxide, and methane—on flame holding in the premixer are presented. The new fuel injector concept has been incorporated into a full-scale, multinozzle combustor can with an energy conversion rate of more than 10 MW at F-class conditions. The full-can testing was conducted at full gas turbine conditions and various fuel compositions of hydrogen, natural gas, and nitrogen. This combustion system has accumulated over 100 h of fired testing at full load with hydrogen comprising over 90% of the reactants by volume. NOx emissions (ppm) have been measured in the single digits with hydrogen-nitrogen fuel at target gas turbine pressure and temperatures. Results of the testing show that small-scale fuel-air mixing can deliver a reliable, low-NOx solution to hydrogen combustion in advanced gas turbines.

The system-level simulation model for Natural Gas Combined-Cycle (NGCC) plant combines advanced G class turbine with various fuels was performed in the study. The commercial chemical process simulator, Pro/II® V8.1.1, is used in the study to build the analysis model. There are three major sections which are gas turbine (GT), heat recovery steam generator (HRSG) and steam turbine (ST).The study envisages two analyses as the basic and feasibility cases. The former is the benchmark case which is verified with the reference data of exist NGCC power plant located in Dah-Tarn, Taiwan. The Dah-Tarn NGCC power plant introduces the advanced M501G gas turbine from Mitsubishi Heavy Industries, Ltd. (MHI) and the system efficiency of the combined-cycle is 58.75 % (LHV). The latter introduces a feasibility study with advanced gas turbine and actual parameters in Taiwan. The SNG from carbonate fuel feed to M501G based combined-cycle is evaluated in the feasibility study cases first, and the mixture gas of SNG and syngas is also evaluated to compare the different of overall performance with the pure SNG case.The results show that the system efficiency of pure SNG case is around 57 % (LHV). For the mixture gas case, the maximum ratio of syngas to SNG is 1:19, due to keep the same composition of methane is 85.9 % with the Dah-Tarn NGCC power plant. The efficiency of mixture gas case is 55.75 % (LHV).The study shows the possibility way to use coal and reduce the CO2 emission. The another advantage is the using of SNG could increases the usage of combined-cycle in Taiwan, due to the prices of natural gas is higher than coal in Taiwan and results in the higher idle capacity.

Sintered α-SiC (Hexoloy® SA*) turbine engine components have been fabricated by Carborundum for the Advanced Gas Turbine (AGT) Program and, more recently, for the Advanced Turbine Technology Applications Project (ATTAP) using three primary forming procedures — injection molding, cold isostatic pressing (CIP) followed by green machining, and slip casting. The near net-shape fabrication of injection molded AGT-100 radial rotors for the Allison Gas Turbine Division (AGTD) of General Motors Corporation and, more recently, AGT-5 axial rotors, has been demonstrated. The current emphasis at Carborundum is to refine the injection molding process, bringing it to a performance and reproducibility level sufficient for production needs. The process changes leading to increases in component strength from approximately 380 MPa (55 ksi) to 595 MPa (86 ksi) will be discussed, as well as investigation of the failure mechanism and proposed process modifications to enhance properties even further.

Nowadays, the issues of the energy and environment become more and more serious with the demand of energy increasing drastically. The advanced gas turbine cycles provide the opportunities to solve these issues. Humid air turbine (HAT) cycle, which is one of the most promising cycles with high efficiency, low emissions and low unit investment costs, is a prominent representation of the advanced gas turbine cycles. In this paper, an aero-derivative three-shaft gas turbine was converted to the HAT cycle. The aero-derivative is one of the most efficient simple cycles, whose system efficiency can reach 40%. And it is an effective solution to transform the advanced technology from the aeronautical filed to the industrial application. In order to investigate the performance of the HAT cycle, the saturator model was established based on the saturation curve and the saturator working line. Additionally, it was validated that the saturator model was consistent with the steady state experimental results very well. The maximum error of the outlet air temperature is less than 0.8% and the maximum error of the outlet air humidity is less than 1.9%. Three different HAT cycle systems were designed and simulated on the MATLAB platform. The thermodynamic performance of the three HAT systems on the design point shows that case 2 is the better one, which means that the aftercooler does not have obvious benefits for system performance and NOx emissions. Then, the effects of the ambient temperature on the case 2 and simple cycle were investigated. The results show that the HAT cycle has the more favorable off-design performance than the simple cycle when the ambient temperature is changed.

Under the U.S. Dept. of Energy/National Aeronautics and Space Administration (DOE/NASA) funded Ceramic Turbine Engine Demonstration Project, formerly the Advanced Turbine Technology Applications Project (ATTAP), AlliedSignal Engines is addressing the remaining critical concerns slowing the commercialization of structural ceramics in gas turbine engines. These issues include demonstration of ceramic component reliability, readiness of ceramic suppliers to support ceramic production needs, and development of ceramic design technologies. The AlliedSignal/Garrett Model 331-200[CT] Auxiliary Power Unit (APU) is being used as a ceramics test bed engine. The first-stage turbine blades and nozzles were redesigned using ceramic materials, employing the design methods developed during the earlier DOE/NASA-funded Advanced Gas Turbine (AGT) and ATTAP programs. Ceramic engine components have been fabricated and are now being evaluated in laboratory engine testing. The fabrication processes for these components will provide the framework for a demonstration of manufacturing process scale-up to the minimum level for commercial viability. The laboratory engine testing is helping to refine the component designs and focus the development of ceramic component technologies. Extended engine endurance testing and field testing in commercial aircraft is planned to demonstrate ceramic component reliability. Significant progress has been made during 1994. An engine with ceramic turbine nozzles was successfully operated and engine tests in the laboratory are continuing to gather useful data. An engine equipped with ceramic blades was also tested, but blade fractures occurred, interrupting operation. An extensive investigation has identified possible vibration and contact problems. Investigative evaluation efforts are continuing to identify the problem source and determine go-forward plans for ceramic blade development. Component design technologies have progressed in the areas of modeling particle impact pulverization, development of a ceramic hot corrosion environmental life model, and methods for evaluating ceramic contact damage. The planned ceramic manufacturing scale-up was initiated with two ceramics vendors, Norton Advanced Ceramics (East Granby, CT) and AlliedSignal Ceramic Components (Torrance, CA). The scaleup demonstration program is emphasizing improvement of ceramic processing yields and increased production rates. Work summarized in this paper was funded by the U.S. Dept. of Energy (DOE) Office of Transportation Technologies, as part of the Turbine Engine Technologies Program, and administered by the NASA Lewis Research Center, Cleveland, OH under Contract No. DEN3-335.

The Ceramic Stationary Gas Turbine (CSGT) Program has utilized the SPSLIFE computer code to evaluate the preliminary design of ceramic components. The CSGT program is being performed under the sponsorship of the United States Department of Energy, Office of Industrial Technology, to improve the performance of stationary gas turbines in cogeneration through the selective replacement of hot section components with ceramic parts. Preliminary design evaluation and life assessment results are presented here for the following components: (1) Stage 1 turbine blade, (2) Stage 1 turbine nozzle, and (3) combustor inner liner. From the results of the analysis, recommendations are made for improving the life and reliability of the components. All designs were developed in Phase I (preliminary design) of the CSGT program and will be optimized in Phase II (detail design) of the program.

This paper describes the FT8A, an advanced state of the art, high performance aeroderivative gas turbine under development for variable speed mechanical drive industrial applications. The gas generator, common to the recently developed FT8, is derived from the Pratt & Whitney JT8D-200 series aircraft engine. The power turbine is being designed and developed by Turbo Power and Marine Systems, Inc. (TPM) and MAN Gutehoffnungshütte AG (MAN GHH) under a joint collaboration program. The power turbine features a three stage rotor simply supported between antifriction bearings, advanced aerodynamics, and a low loss exhaust diffuser/collector system. Design features, performance and typical applications of the FT8A are presented.

29 - Gas turbine support systems

The concept of hybrids combining fuel cell and gas turbine systems is without question neoteric, and probably is less than eight years old. However, this concept is in a sense a logical development derived from the many early systems that embodied the key features of rotating machinery to compress air. It was the introduction of high temperature fuel cells such as the solid oxide fuel cell (SOFC) that allowed the concept of hybrid gas turbine fuel cell systems to take root. The SOFC with an operating temperature circa 1000° C matched well with small industrial gas turbines that had firing temperatures on the same order. The recognition that the SOFC could be substituted for the gas turbine combustor was the first step into the realm of fuel cell topping systems. Fuel cells in general were recognized as having higher efficiencies at elevated pressures. Thus the hybrid topping system where the gas turbine pressurized the fuel cell and the fuel cell supplied the hot gases for expansion over the turbine promised to provide a high level of synergy between the two systems. Bottoming systems using the exhaust of a gas turbine as the working fluid of a fuel cell such as the molten carbonate fuel cell (MCFC) have been identified and are potential future power generation hybrid systems. The MCFC is especially well suited to the bottoming role because of the need to have carbon dioxide present in the inlet air stream. The carbon dioxide in the gas turbine exhaust allows the high temperature blower, normally used to recirculate and inject exhaust products into the inlet air, to be eliminated. Hybrid systems have the potential of achieving fossil fuel to electricity conversion efficiencies on the order of 70% and higher. The costs of hybrid systems in dollars per kilowatt are generally higher than say an advanced gas turbine that is available today but not by much. The net energy output over the life of a hybrid topping system is similar to that of a recuperated gas turbine but possibly lower than a high-efficiency simple-cycle machine, depending on the efficiency of the hybrid. Methodologies to aid in the selection of the hybrid system for future development have to be developed and used consistently. Life cycle analyses (LFA) provide a framework for such selection processes. In particular the concept of net energy output provides a mechanism to assign relative worth to competing concepts.

This paper aims at carrying out comparative performance analysis of simple and advanced cycles large-scale aero-derivative industrial gas turbines derived from aircraft turbofan engines. The investigation involves technical performances of three large-scale aero-derivative engine cycles based on existing and projected cycles for applications in land based power generation and Combined-Heat-and-Power (CHP). Preliminary design and performance simulation were implemented of a simple cycle (baseline) three-spool 100 MW aero-derivative engine model, intercooled and intercooled/recuperated engine cycles of the same 100 MW nominal power rating. In the analysis, design point and off-design performances of the engine models were established. The results indicate that to a large extent, the advanced engine cycles showed superior performance in terms of thermal efficiency, and fuel flow. In numerical terms, thermal efficiencies of intercooled engine cycle, and intercooled/recuperated engine cycles, over the simple cycle at design point increased by 2.42% and 0.94% respectively, whereas heat rates of these cycles over simple cycle at design point decreased by 2.37% and 0.93% respectively. It is worthy of note that for large-scale aero-derivative gas turbines having power rating of 100 MW and above, intercooled cycle would consume less fuel than intercooled-recuperated and simple cycles. This finding would actually aid good choice of cycle option for large-scale aero-derivative gas turbine designers, manufacturers and users.

Gas turbines are used for aircraft propulsion and land-based power generation or industrial applications. Thermal efficiency and power output of gas turbines increase with increasing turbine rotor inlet temperatures (RIT). Current advanced gas turbine engines operate at turbine RIT (1700 °C) far higher than the melting point of the blade material (1000 °C); therefore, turbine blades are cooled by compressor discharge air (700 °C). To design an efficient cooling system, it is a great need to increase the understanding of gas turbine heat transfer behaviors within complex 3D high-turbulence unsteady engine-flow environments. Moreover, recent research focuses on aircraft gas turbines operating at even higher RIT with limited cooling air and land-based gas turbines burn coal-gasified fuels with a higher heat load. It is important to understand and solve gas turbine heat transfer problems under new harsh working environments. The advanced cooling technology and durable thermal barrier coatings play critical roles for the development of advanced gas turbines with near zero emissions for safe and long-life operation. This paper reviews fundamental gas turbine heat transfer research topics and documents important relevant papers for future research.

In September 1988, a Hitachi-GE model PG5341 gas turbine installed at the Tokuyama refinery of Idemitsu Kosan Co., Ltd. (Japan) successfully recorded 100,325 hours of base load operation over a period of 13 years with 99.4% reliability. The generated power totalled 1,341,770 MWh at the time of final shutdown. The gas turbine, burning Bunker A oil, LPG, and heavy distillate oil, had been the main equipment in a cogeneration plant with a simple heat recovery steam generator using waste heat from the exhaust gas, plus a refired boiler. It was expected that several costly hot gas path components of this turbine would have to be replaced in the near future, and it was not as fuel efficient as more modern designs, so it was decided to replace the PG5341 with a Hitachi H-25 gas turbine. This new model H-25 is designed to have a rated output of 26,200kW and an efficiency of 32.3% (LHV) at the generator terminals under ISO conditions. By the use of a pressure ratio of 14.7 (up from 10.1) and a combustor outlet gas temperature of 1,260°C (up from 980°C), it is expected that efficiency of gas turbine will be improved relatively by 18.7% on a design basis, compared with the PG5341. A factory full-load test of the prototype H-25 gas turbine was completed in August 1988 with excellent results. This machine has been in place and in operation at the Tokuyama plant since the end of November 1988. This is the first commercial application of the Hitachi H-25 advanced gas turbine.

The U. S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) is directing substantial programs in the development and encouragement of new energy technologies. Among them are renewable energy and distributed energy resource technologies. As part of its ongoing effort to document the status and potential of these technologies, DOE EERE directed the National Renewable Energy Laboratory to lead an effort to develop and publish Distributed Energy Technology Characterizations (TCs) that would provide both the department and energy community with a consistent and objective set of cost and performance data in prospective electric-power generation applications in the United States. Toward that goal, DOE/EERE - joined by the Electric Power Research Institute (EPRI) - published the Renewable Energy Technology Characterizations in December 1997.As a follow-up, DOE EERE - joined by the Gas Research Institute - is now publishing this document, Gas-Fired Distributed Energy Resource Technology Characterizations.

The Externally-Fired Combined Cycle (EFCC) is an attractive emerging technology for powering high efficiency combined gas and steam turbine cycles with coal or other ash bearing fuels. In the EFCC, the heat input to a gas turbine is supplied indirectly through a ceramic air heater. The air heater, along with an atmospheric coal combustor and ancillary equipment, replaces the conventional gas turbine combustor. A steam generator located downstream from the ceramic air heater and steam turbine cycle, along with an exhaust cleanup system, completes the combined cycle. A key element of the EFCC Development Program, the 25 MMBtu/h heat-input Kennebunk Test Facility (KTF), has recently begun operation. The KTF has been operating with natural gas and will begin operating with coal in early 1995. The US Department of Energy selected an EFCC repowering of the Pennsylvania Electric Company`s Warren Station for funding under the Clean Coal Technology Program Round V. The project focuses on repowering an existing 48 MW (gross) steam turbine with an EFCC power island incorporating a 30 MW gas turbine, for a gross power output of 78 MW and a net output of 72 MW. The net plant heat rate will be decreased by approximately 30% tomore » below 9,700 Btu/kWh. Use of a dry scrubber and fabric filter will reduce sulfur dioxide (SO{sub 2}) and particulate emissions to levels under those required by the Clean Air Act Amendments (CAAA) of 1990. Nitrogen oxides (NO{sub x}) emissions are controlled by the use of staged combustion. The demonstration project is currently in the engineering phase, with startup scheduled for 1997. This paper discusses the background of the EFCC, the KTF, the Warren Station EFCC Clean Coal Technology Demonstration Project, the commercial plant concept, and the market potential for the EFCC.« less