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1
Fersini, Maurizio, R. Bianco, L. De Lorenzis, Antonio Licciulli, G. Pasquero, and G. Zanon. "Thermo-Structural Analysis of Ceramic Vanes for Gas Turbines." Advances in Science and Technology 45 (October 2006): 1759–64. http://dx.doi.org/10.4028/www.scientific.net/ast.45.1759.
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Advanced structural ceramics such as Hot Pressed Silicon Nitride (HPSN) and Reaction Bonded Silicon Carbide (RBSC), thanks to their low density (3.1 ÷ 3.4 gr/cm3) and to their thermostructural properties, are interesting candidates for aerospace applications. This research investigates the feasibility of employing such monolithic advanced ceramics for the production of turbine vanes for aerospace applications, by means of a finite element analysis. A parametric study is performed to analyse the influence of the coefficient of thermal expansion, the specific heat, the thermal conductivity, and the Weibull modulus on structural stability, heat transfer properties and thermomechanical stresses under take-off and flying conditions. A nodal point that is evidenced is the high intensity of thermal stresses on the vane, both on steady state and in transient conditions. In order to reduce such stresses various simulations have been carried out varying geometrical parameters such as the wall thickness. Several open questions are evidenced and guidelines are drawn for the design and production of ceramic vanes for gas turbines.
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Lock, Gary D., Michael Wilson, and J. Michael Owen. "Influence of Fluid Dynamics on Heat Transfer in a Preswirl Rotating-Disk System." Journal of Engineering for Gas Turbines and Power 127, no. 4 (March 1, 2004): 791–97. http://dx.doi.org/10.1115/1.1924721.
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Modern gas turbines are cooled using air diverted from the compressor. In a “direct-transfer” preswirl system, this cooling air flows axially across the wheel space from stationary preswirl nozzles to receiver holes located in the rotating turbine disk. The distribution of the local Nusselt number Nu on the rotating disk is governed by three nondimensional fluid-dynamic parameters: preswirl ratio βp, rotational Reynolds number Reϕ, and turbulent flow parameter λT. This paper describes heat transfer measurements obtained from a scaled model of a gas turbine rotor-stator cavity, where the flow structure is representative of that found in the engine. The experiments reveal that Nu on the rotating disk is axisymmetric except in the region of the receiver holes, where significant two-dimensional variations have been measured. At the higher coolant flow rates studied, there is a peak in heat transfer at the radius of the preswirl nozzles associated with the impinging jets from the preswirl nozzles. At lower coolant flow rates, the heat transfer is dominated by viscous effects. The Nusselt number is observed to increase as either Reϕ or λT increases.
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Valenti, Michael. "Turbines for Peace." Mechanical Engineering 122, no. 08 (August 1, 2000): 70–72. http://dx.doi.org/10.1115/1.2000-aug-5.
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This article discusses that military-sponsored research tools can improve the machines that drive civil applications. The Defense Evaluation and Research Agency (DERA) researchers tested the engine of the legendary DeHavilland Vampire single seat jet fighter in the late 1940s. This Vampire is owned by Fred Ihlenburg, president of Yakity Yaks Inc., an importer of foreign military aircraft, based in Aurora, Oregon. DERA is investigating heat transfer on turbine blades to help gas turbine manufacturers develop a cooling system that will keep blades at an optimum temperature while minimizing losses in engine performance. More efficient cooling means less air is bled from the compressor, thus improving performance while extending blade life. This work was co-funded by the Central European Commission under the Brite Euram Fourth-Framework Initiative, which is part of the European Union’s strategy to enhance European global competitiveness, and Britain’s Department of Trade and Industry’s Civil Aircraft Research and Technology Demonstration Program. The British program aims to advance the capabilities of the United Kingdom’s civil aerospace companies.
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Rice, I. G. "Thermodynamic Evaluation of Gas Turbine Cogeneration Cycles: Part I—Heat Balance Method Analysis." Journal of Engineering for Gas Turbines and Power 109, no. 1 (January 1, 1987): 1–7. http://dx.doi.org/10.1115/1.3240001.
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This paper presents a heat balance method of evaluating various open-cycle gas turbines and heat recovery systems based on the first law of thermodynamics. A useful graphic solution is presented that can be readily applied to various gas turbine cogeneration configurations. An analysis of seven commercially available gas turbines is made showing the effect of pressure ratio, exhaust temperature, intercooling, regeneration, and turbine rotor inlet temperature in regard to power output, heat recovery, and overall cycle efficiency. The method presented can be readily programmed in a computer, for any given gaseous or liquid fuel, to yield accurate evaluations. An X–Y plotter can be utilized to present the results.
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Kurowski, Marcin, Ryszard Szwaba, Janusz Telega, Pawel Flaszynski, Fernando Tejero, and Piotr Doerffer. "Wall distance effect on heat transfer at high flow velocity." Aircraft Engineering and Aerospace Technology 91, no. 9 (October 7, 2019): 1180–86. http://dx.doi.org/10.1108/aeat-01-2018-0022.
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Purpose This paper aims to present the results of experimental and numerical research on heat transfer distribution under the impinging jets at various distances from the wall and high jet velocity. This work is a part of the INNOLOT Program financed by National Centre for Research and Development. Design/methodology/approach The air jets flow out from the common pipe and impinge on a surface which is cooled by them, and in this way, all together create a model of external cooling system of low-pressure gas turbine casing. Measurements were carried out for the arrangement of 26 in-line jets with orifice diameter of 0.9 mm. Heat transfer distribution was investigated for various Reynolds and Mach numbers. The cooled wall, made of transparent PMMA, was covered with a heater foil on which a layer of self-adhesive liquid crystal foil was placed. The jet-to-wall distance was set to h = from 4.5 to 6 d. Findings The influence of various Reynolds and Mach numbers on cooled flat plate and jet-to-wall distance in terms of heat transfer effectiveness is presented. Experimental results used for the computational fluid dynamics (CFD) model development, validation and comparison with numerical results are presented. Practical implications Impinging air jets is a commonly used technique to cool advanced turbines elements, as it produces large convection enhancing the local heat transfer, which is a critical issue in the development of aircraft engines. Originality/value The achieved results present experimental investigations carried out to study the heat transfer distribution between the orthogonally impinging jets from long round pipe and flat plate. Reynolds number based on the jet orifice exit conditions was varied between 2,500 and 4,000; meanwhile, for such Re, the flow velocity in jets was particularly very high, changing from M = 0.56 to M = 0.77. Such flow conditions combination, i.e. the low Reynolds number and very high flow velocity cannot be found in the existing literature.
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Du, Haifen, Daimei Xie, Wei Jiang, Tong Chen, and Jianshu Gao. "Numerical Study on Heat Transfer Enhancement of Swirl Chamber on Gas Turbine Blade." International Journal of Turbo & Jet-Engines 35, no. 4 (December 19, 2018): 403–12. http://dx.doi.org/10.1515/tjj-2016-0049.
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Abstract The optimization of turbine cooling design has become a new research field of gas turbine. The swirl chamber is a prospect cooling concept. In this paper, the numerical simulation of the swirl chamber is carried out by FLUENT. The influence of inlet size parameters, temperature ratio and inlet Reynolds number on the enhanced heat transfer of swirl chamber is studied. The results show that, in the range of the studied condition, Nusselt number decreases with the height, the width, the ratio of width to height and Reynolds number. It also shows that comprehensive heat transfer effect is best at d=20 mm and enhances observably with the enlargement of width, width height ratio, and Reynolds number. Friction factor increases with height, width, temperature ratio and Reynolds number decreases. It is increased by increasing width height ratio. Nusselt number and comprehensive heat transfer effect decrease a little with aggrandizement of temperature ratio.
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Schiele, Ralf, and Sigmar Wittig. "Gas Turbine Heat Transfer: Past and Future Challenges." Journal of Propulsion and Power 16, no. 4 (July 2000): 583–89. http://dx.doi.org/10.2514/2.5611.
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Freedman, B. Z., and N. Lior. "A Novel High-Temperature Ejector-Topping Power Cycle." Journal of Engineering for Gas Turbines and Power 116, no. 1 (January 1, 1994): 1–7. http://dx.doi.org/10.1115/1.2906793.
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A novel, patented topping power cycle is described that takes its energy from a very high-temperature heat source and in which the temperature of the heat sink is still high enough to operate another, conventional power cycle. The top temperature heat source is used to evaporate a low saturation pressure liquid, which serves as the driving fluid for compressing the secondary fluid in an ejector. Due to the inherently simple construction of ejectors, they are well suited for operation at temperatures higher than those that can be used with gas turbines. The gases exiting from the ejector transfer heat to the lower temperature cycle, and are separated by condensing the primary fluid. The secondary gas is then used to drive a turbine. For a system using sodium as the primary fluid and helium as the secondary fluid, and using a bottoming Rankine steam cycle, the overall thermal efficiency can be at least 11 percent better than that of conventional steam Rankine cycles.
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Lock, Gary D., Youyou Yan, Paul J. Newton, Michael Wilson, and J. Michael Owen. "Heat Transfer Measurements Using Liquid Crystals in a Preswirl Rotating-Disk System." Journal of Engineering for Gas Turbines and Power 127, no. 2 (April 1, 2005): 375–82. http://dx.doi.org/10.1115/1.1787509.
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Preswirl nozzles are often used in gas turbines to deliver the cooling air to the turbine blades through receiver holes in a rotating disk. The distribution of the local Nusselt number, Nu, on the rotating disk is governed by three nondimensional fluid-dynamic parameters: preswirl ratio, βp, rotational Reynolds number, Reϕ, and turbulent flow parameter, λT. A scaled model of a gas turbine rotor–stator cavity, based on the geometry of current engine designs, has been used to create appropriate flow conditions. This paper describes how a thermochromic liquid crystal, in conjunction with a stroboscopic light and digital camera, is used in a transient experiment to obtain contour maps of Nu on the rotating disk. The thermal boundary conditions for the transient technique are such that an exponential-series solution to Fourier’s one-dimensional conduction equation is necessary. A method to assess the uncertainty in the measurements is discussed and these uncertainties are quantified. The experiments reveal that Nu on the rotating disk is axisymmetric except in the region of the receiver holes, where significant two-dimensional variations have been measured. At the higher coolant flow rates studied, there is a peak in heat transfer at the radius of the preswirl nozzles. The heat transfer is governed by two flow regimes: one dominated by inertial effects associated with the impinging jets from the preswirl nozzles, and another dominated by viscous effects at lower flow rates. The Nusselt number is observed to increase as either Reϕ or λT increases.
10
Becker, B., and B. Schetter. "Gas Turbines Above 150 MW for Integrated Coal Gasification Combined Cycles (IGCC)." Journal of Engineering for Gas Turbines and Power 114, no. 4 (October 1, 1992): 660–64. http://dx.doi.org/10.1115/1.2906639.
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Commercial IGCC power plants need gas turbines with high efficiency and high power output in order to reduce specific installation costs and fuel consumption. Therefore the well-proven 154 MW V94.2 and the new 211 MW V94.3 high-temperature gas turbines are well suited for this kind of application. A high degree of integration of the gas turbine, steam turbine, oxygen production, gasifier, and raw gas heat recovery improves the cycle efficiency. The air use for oxygen production is taken from the gas turbine compressor. The N2 fraction is recompressed and mixed with the cleaned gas prior to combustion. Both features require modifications of the gas turbine casing and the burners. Newly designed burners using the coal gas with its very low heating value and a mixture of natural gas and steam as a second fuel are developed for low NOx and CO emissions. These special design features are described and burner test results presented.
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Wedlake, E. T., A. J. Brooks, and S. P. Harasgama. "Aerodynamic and Heat Transfer Measurements on a Transonic Nozzle Guide Vane." Journal of Turbomachinery 111, no. 1 (January 1, 1989): 36–42. http://dx.doi.org/10.1115/1.3262234.
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Experimental determination of heat transfer rates to gas turbine blading plays an important part in the improvement of both the validation of existing design methods and the development of improved design codes. This paper describes a series of tests on an annular cascade of nozzle guide vanes designed for a high-work-capacity single-stage transonic turbine. The tests were carried out in the Isentropic Light Piston Cascade at the Royal Aerospace Establishment, Pyestock, and a brief description of this new test facility is included. Measurements of local heat transfer rates and aerodynamic data around the blade surface and on the end walls are described.
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Nakagaki, T., T. Ogawa, H. Hirata, K. Kawamoto, Y. Ohashi, and K. Tanaka. "Development of Chemically Recuperated Micro Gas Turbine." Journal of Engineering for Gas Turbines and Power 125, no. 1 (December 27, 2002): 391–97. http://dx.doi.org/10.1115/1.1520158.
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Micro gas turbines (MGTs) are subject to certain problems, notably low thermal efficiency of the system and high emission including NOx. The chemically recuperated gas turbine (CRGT) system introduced in this paper is one of the most promising solutions to these problems. The CRGT system we propose uses an endothermic reaction of methane steam reforming for heat recovery. It is usually thought that the reaction of methane steam reforming does not occur sufficiently to recover heat at the temperature of turbine exhaust, but we confirmed sufficient reaction occurred at such low temperature and that applications of the chemical recuperation system to some commercial MGTs are effective for increasing the efficiency.
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Chmielniak, Tadeusz, Gerard Kosman, and Wojciech Kosman. "Analysis of Cycle Configurations for the Modernization of Combined Heat and Power Plant by Fitting a Gas Turbine System." Journal of Engineering for Gas Turbines and Power 126, no. 4 (October 1, 2004): 816–22. http://dx.doi.org/10.1115/1.1765126.
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The application of a gas turbine generally allows to increase the number of possible configurations of cogenerated heat and electrical power systems, which became a significant substitute for classic, coal-fired power plants. They are characterized by better thermodynamical, economical, ecological, and operating indexes. Gas turbine units are also the best option for the modernization of existing power plants. This paper discusses the effectiveness of various technological configurations with gas turbines, which are to be applied during modernization projects of already existing conventional combined heat and power plants. In the analysis enthalpy and entropy methods were applied. Algorithms of the entropy method allow to determine the entropy generation in each section of a combined heat and power (CHP) plant. Several criteria were taken into consideration while analyzing the effectiveness of technological cycle configurations with gas turbines. These include the energy effectiveness, the efficiency of the HRSG and the steam cycle, the efficiency of the whole thermal electric power station, the exergetic efficiency of the HRSG and the steam cycle, and the fuel efficiency index. It was assumed that gas turbines operate under their nominal conditions. The composite curves were also taken into consideration while choosing the type of the turbine. The modernization project tends not to eliminate those existing power plant sections (machines and equipment), which are able to operate further. The project suggests that those units should remain in the system, which satisfy the applied durability criterion. The last phase of the optimization project focuses on the sensibility verification of several steam-gas CHP plant parameters and their influence on the whole system.
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El Hadik, A. A. "The Impact of Atmospheric Conditions on Gas Turbine Performance." Journal of Engineering for Gas Turbines and Power 112, no. 4 (October 1, 1990): 590–96. http://dx.doi.org/10.1115/1.2906210.
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In a hot summer climate, as in Kuwait and other Arabian Gulf countries, the performance of a gas turbine deteriorates drastically during the high-temperature hours (up to 60°C in Kuwait). Power demand is the highest at these times. This necessitates an increase in installed gas turbine capacities to balance this deterioration. Gas turbines users are becoming aware of this problem as they depend more on gas turbines to satisfy their power needs and process heat for desalination due to the recent technical and economical development of gas turbines. This paper is devoted to studying the impact of atmospheric conditions, such as ambient temperature, pressure, and relative humidity on gas turbine performance. The reason for considering air pressures different from standard atmospheric pressure at the compressor inlet is the variation of this pressure with altitude. The results of this study can be generalized to include the cases of flights at high altitudes. A fully interactive computer program based on the derived governing equations is developed. The effects of typical variations of atmospheric conditions on power output and efficiency are considered. These include ambient temperature (range from −20 to 60°C), altitude (range from zero to 2000 m above sea level), and relative humidity (range from zero to 100 percent). The thermal efficiency and specific net work of a gas turbine were calculated at different values of maximum turbine inlet temperature (TIT) and variable environmental conditions. The value of TIT is a design factor that depends on the material specifications and the fuel/air ratio. Typical operating values of TIT in modern gas turbines were chosen for this study: 1000, 1200, 1400, and 1600 K. Both partial and full loads were considered in the analysis. Finally the calculated results were compared with actual gas turbine data supplied by manufacturers.
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Rice, I. G. "Split Stream Boilers for High-Temperature/High-Pressure Topping Steam Turbine Combined Cycles." Journal of Engineering for Gas Turbines and Power 119, no. 2 (April 1, 1997): 385–94. http://dx.doi.org/10.1115/1.2815586.
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Research and development work on high-temperature and high-pressure (up to 1500°F TIT and 4500 psia) topping steam turbines and associated steam generators for steam power plants as well as combined cycle plants is being carried forward by DOE, EPRI, and independent companies. Aeroderivative gas turbines and heavy-duty gas turbines both will require exhaust gas supplementary firing to achieve high throttle temperatures. This paper presents an analysis and examples of a split stream boiler arrangement for high-temperature and high-pressure topping steam turbine combined cycles. A portion of the gas turbine exhaust flow is run in parallel with a conventional heat recovery steam generator (HRSG). This side stream is supplementary fired opposed to the current practice of full exhaust flow firing. Chemical fuel gas recuperation can be incorporated in the side stream as an option. A significant combined cycle efficiency gain of 2 to 4 percentage points can be realized using this split stream approach. Calculations and graphs show how the DOE goal of 60 percent combined cycle efficiency burning natural gas fuel can be exceeded. The boiler concept is equally applicable to the integrated coal gas fuel combined cycle (IGCC).
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Yamawaki, S., T. Yoshida, M. Taki, and F. Mimura. "Fundamental Heat Transfer Experiments of Heat Pipes for Turbine Cooling." Journal of Engineering for Gas Turbines and Power 120, no. 3 (July 1, 1998): 580–87. http://dx.doi.org/10.1115/1.2818186.
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Fundamental heat transfer experiments were carried out for three kinds of heat pipes that may be applied to turbine cooling in future aero-engines. In the turbine cooling system with a heat pipe, heat transfer rate and start-up time of the heat pipe are the most important performance criteria to evaluate and compare with conventional cooling methods. Three heat pipes are considered, called heat pipe A, B, and C, respectively. All heat pipes have a stainless steel shell and nickel sintered powder metal wick. Sodium (Na) was the working fluid for heat pipes A and B; heat pipe C used eutectic sodium-potassium (NaK). Heat pipes B and C included noncondensible gas for rapid start-up. There were fins on the cooling section of heat pipes. In the experiments, and infrared image furnace supplied heat to the heat pipe simulating turbine blade surface conditions. In the results, heat pipe B demonstrated the highest heat flux of 17 to 20 W/cm2. The start-up time was about 6 minutes for heat pipe B and about 16 minutes for heat pipe A. Thus, adding noncondensible gas effectively reduced start-up time. Although NaK is a liquid phase at room temperature, the startup time of heat pipe C (about 7 to 8 minutes) was not shorter than the heat pipe B. The effect of a gravitational force on heat pipe performance was also estimated by inclining the heat pipe at an angle of 90 deg. There was no significant gravitational dependence on heat transport for heat pipes including noncondensible gas.
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Fukuizumi, Y., J. Masada, V. Kallianpur, and Y. Iwasaki. "Application of “H Gas Turbine” Design Technology to Increase Thermal Efficiency and Output Capability of the Mitsubishi M701G2 Gas Turbine." Journal of Engineering for Gas Turbines and Power 127, no. 2 (April 1, 2005): 369–74. http://dx.doi.org/10.1115/1.1850490.
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Mitsubishi completed design development and verification load testing of a steam-cooled M501H gas turbine at a combined cycle power plant at Takasago, Japan in 2001. Several advanced technologies were specifically developed in addition to the steam-cooled components consisting of the combustor, turbine blades, vanes, and the rotor. Some of the other key technologies consisted of an advanced compressor with a pressure ratio of 25:1, active clearance control, and advanced seal technology. Prior to the M501H, Mitsubishi introduced cooling-steam in “G series” gas turbines in 1997 to cool combustor liners. Recently, some of the advanced design technologies from the M501H gas turbine were applied to the G series gas turbine resulting in significant improvement in output and thermal efficiency. A noteworthy aspect of the technology transfer is that the upgraded G series M701G2 gas turbine has an almost equivalent output and thermal efficiency as H class gas turbines while continuing to rely on conventional air cooling of turbine blades and vanes, and time-proven materials from industrial gas turbine experience. In this paper we describe the key design features of the M701G2 gas turbine that make this possible such as the advanced 21:1 compressor with 14 stages, an advanced premix DLN combustor, etc., as well as shop load test results that were completed in 2002 at Mitsubishi’s in-house facility.
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Lewis, Paul, Mike Wilson, Gary Lock, and J. Michael Owen. "Physical Interpretation of Flow and Heat Transfer in Preswirl Systems." Journal of Engineering for Gas Turbines and Power 129, no. 3 (July 20, 2006): 769–77. http://dx.doi.org/10.1115/1.2436572.
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This paper compares heat transfer measurements from a preswirl rotor–stator experiment with three-dimensional (3D) steady-state results from a commercial computational fluid dynamics (CFD) code. The measured distribution of Nusselt number on the rotor surface was obtained from a scaled model of a gas turbine rotor–stator system, where the flow structure is representative of that found in an engine. Computations were carried out using a coupled multigrid Reynolds-averaged Navier-Stokes (RANS) solver with a high Reynolds number k-ε∕k-ω turbulence model. Previous work has identified three parameters governing heat transfer: rotational Reynolds number (Reϕ), preswirl ratio (βp), and the turbulent flow parameter (λT). For this study rotational Reynolds numbers are in the range 0.8×106<Reϕ<1.2×106. The turbulent flow parameter and preswirl ratios varied between 0.12<λT<0.38 and 0.5<βp<1.5, which are comparable to values that occur in industrial gas turbines. Two performance parameters have been calculated: the adiabatic effectiveness for the system, Θb,ad, and the discharge coefficient for the receiver holes, CD. The computations show that, although Θb,ad increases monotonically as βp increases, there is a critical value of βp at which CD is a maximum. At high coolant flow rates, computations have predicted peaks in heat transfer at the radius of the preswirl nozzles. These were discovered during earlier experiments and are associated with the impingement of the preswirl flow on the rotor disk. At lower flow rates, the heat transfer is controlled by boundary-layer effects. The Nusselt number on the rotating disk increases as either Reϕ or λT increases, and is axisymmetric except in the region of the receiver holes, where significant two-dimensional variations are observed. The computed velocity field is used to explain the heat transfer distributions observed in the experiments. The regions of peak heat transfer around the receiver holes are a consequence of the route taken by the flow. Two routes have been identified: “direct,” whereby flow forms a stream tube between the inlet and outlet; and “indirect,” whereby flow mixes with the rotating core of fluid.
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Lugand, P., and C. Parietti. "Combined Cycle Plants With Frame 9F Gas Turbines." Journal of Engineering for Gas Turbines and Power 113, no. 4 (October 1, 1991): 475–81. http://dx.doi.org/10.1115/1.2906264.
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The new 200 MW class MS 9001F gas turbines allow combined cycle plants to reach even higher output levels and greater efficiency ratings. Size factor and higher firing temperatures, with a three-pressure level steam reheat cycle, offer plant efficiencies in excess of 53 percent. Heat recovery steam generators have been designed to accommodate catalytic reduction elements limiting flue gas NOx emissions to as low as 10 ppm VD (15 percent O2). A range of steam turbine models covers the different possible configurations. Various arrangements based on the 350 or 650 MW power generation modules can be optimally configured to the requirements of each site.
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Błachnio, Józef. "The Effect of High Temperature on the Degradation of Heat-Resistant and High-Temperature Alloys." Solid State Phenomena 147-149 (January 2009): 744–51. http://dx.doi.org/10.4028/www.scientific.net/ssp.147-149.744.
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Heat-resistant and high-temperature materials are used to manufacture components, devices, and systems operated at high temperatures, i.e. under severe heat loads. Gas turbines used in the power industry, the traction, marine, and aircraft engines, the aerospace technology, etc. are good examples of such systems. Generally, as the temperature increases, the mechanical strength of materials decreases. While making such materials, there is a tendency to keep possibly low thermal weakening. In the course of operating gas turbines, various kinds of failures/defects/ damages may occur to components thereof, in particular, to blades. Predominating failures/damages are those attributable to the material overheating and thermal fatigue, all of them resulting in the loss of mechanical strength. The paper has been intended to present findings on changes in the microstructure of blades made of nickel-base alloy due to high temperature. The material gets overheated, which results in the deterioration of the microstructure’s condition. The material being in such condition presents low high-temperature creep resistance. Any component, within which such an effect occurs, is exposed to a failure/damage usually resulting in the malfunctioning of the turbine, and sometimes (as with aero-engines) in a fatal accident. Failures/damages of this kind always need major repairs, which are very expensive.
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Ito, K., R. Yokoyama, and Y. Matsumoto. "Optimal Operation of Cogeneration Plants With Steam-Injected Gas Turbines." Journal of Engineering for Gas Turbines and Power 117, no. 1 (January 1, 1995): 60–66. http://dx.doi.org/10.1115/1.2812782.
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The effect of introducing steam-injected gas turbines into cogeneration plants is investigated from economical and energy-saving aspects on the basis of a mathematical programming approach. An optimal planning method is first presented by which the operational strategy is assessed so as to minimize the hourly running cost. Then, a case study is carried out on a plant used for district heating and cooling. Through the study, it is ascertained that the proposed method is a useful tool for the operational planning of steam-injected gas turbine plants, and that these plants can be attractive from economical and energy-saving viewpoints as compared with both simple-cycle gas turbine plus waste heat boiler plants and conventional energy supply ones.
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Organ, A. J. "Analysis of the gas turbine rotary regenerator." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 211, no. 2 (February 1, 1997): 97–111. http://dx.doi.org/10.1243/0954407971526263.
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Recent solution of the ‘Hausen’ regenerator and conjugate heat transfer problems invites a fresh look at the Ritz rotary regenerator. The approach deals readily with the reflux phase (‘hold-up’, flushing or ‘residence time’) and with the effects of friction (re-heating and pressure drop). There is no necessity to assume constant Stanton number, Nst, and friction factor, Cf. With accurate temperature and flow solutions available, recovery ratios in terms of operating parameters are a fait accompli. Optimization for specified duty becomes possible.
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Kolychev, A. V., V. A. Kernozhitskiy, and A. A. Levikhin. "ABOUT MATERIALS OF THE THERMOEMISSION COOLING SYSTEM OF BLADES OF TURBINES OF GAS TURBINE CONVERTERS OF AEROSPACE CRAFTS OF RADIO-ELECTRONIC REMOTE SENSING OF THE EARTH." Issues of radio electronics, no. 7 (July 20, 2018): 89–95. http://dx.doi.org/10.21778/2218-5453-2018-7-89-95.
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Rated estimates of effect of application of the Thermal electron emission Way of Cooling (TWC) of blades of turbines (BT) of the gas turbine converters (GTC) of the Space Aircraft (SA) developed in in D. F. Ustinov Baltic State Technical University «VOENMEH» are given in the present article. Relevance of development of TWC is confirmed by the fact that now in the Russian Federation development of the SA platform with the energy basis at the heart of which the principle of gas turbine transformation is conducted. However, because of low reliability of its basic elements - blades of turbines in operating conditions, it is necessary to reduce temperature in installation that reduces efficiency and increases the weight and dimensions of SA in general. It means that taking into account opportunities of modern means of removal, opportunities for equipment of SA of the radio-electronic equipment are reduced and characteristics of SA with radio equipment in general decrease. Improvement of these characteristics requires increase of reliability of blades of turbines and increase on this basis of temperature of GTC, its efficiency with simultaneous decrease in weight and dimensions. But in this case it is supposed that turbine blades will be made of the ceramic materials functioning in the environment of the inert gases heated from onboard source of heat energy. One of problems at the same time is emergence of temperature gradients, tension and deformations that can lead to emergence of cracks. However, if to execute ceramic blades from metalsimilar connections (borida, carbides, alloys of borid and carbides) using TWC, then opportunity essential (more, than twice) decrease in both TB temperature, and temperature differences, and tension in TB design appears. In article it is also shown that decrease in temperature stresses in design of hot elements at equivalent heat load is reached due to fundamental properties of thermionic emission, namely thanks to dependence of intensity of thermionic emission and electronic cooling on temperature.
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Tuzson, J. "Status of Steam-Injected Gas Turbines." Journal of Engineering for Gas Turbines and Power 114, no. 4 (October 1, 1992): 682–86. http://dx.doi.org/10.1115/1.2906642.
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The injection of exhaust-heat-generated steam into gas turbines for power augmentation has been proven to provide exceptional flexibility of operation in cogeneration applications. The chronology of development of this technology is presented, including a list of available turbines. A description is then given of the design process for converting existing gas turbines to steam injection. Finally, the water purification issue, which is perceived by some as a barrier to cost-effective implementation of such installations, is addressed. It is shown that water purification cost is of the order of 5 percent of the fuel cost and is therefore not a decisive factor.
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Brander, J. A., and D. L. Chase. "Repowering Application Considerations." Journal of Engineering for Gas Turbines and Power 114, no. 4 (October 1, 1992): 643–52. http://dx.doi.org/10.1115/1.2906637.
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As utilities plan for load growth in the 1990s, they are faced with the difficulty of choosing the most economic generation while subject to a number of challenging constraints. These constraints include environmental regulations, particularly the new Clean Air Act, risk aversion, fuel availability and costs, etc. One of the options open to many utilities with existing steam units is repowering, which involves the installation of gas turbine(s) and heat recovery steam generator(s) (HRSG) to convert the steam plant to combined-cycle operation. This paper takes an overall look at the application considerations involved in the use of this generating option, beginning with a summary of the size ranges of existing steam turbines that can be repowered using the GE gas turbine product line. Other topics covered include performance estimates for repowered cycles, current emissions capabilities of GE gas turbines, approximate space requirements and repowering economics.
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Rodi, W., and G. Scheuerer. "Calculation of Heat Transfer to Convection-Cooled Gas Turbine Blades." Journal of Engineering for Gas Turbines and Power 107, no. 3 (July 1, 1985): 620–27. http://dx.doi.org/10.1115/1.3239781.
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A mathematical model is presented for calculating the external heat transfer coefficients around gas turbine blades. The model is based on a finite-difference procedure for solving the boundary-layer equations which describe the flow and temperature field around the blades. The effects of turbulence are simulated by a low-Reynolds number version of the k-ε turbulence model. This allows calculation of laminar and transitional zones and also the onset of transition. Applications of the calculation method are presented to turbine-blade situations which have recently been investigated experimentally. Predicted and measured heat transfer coefficients are compared and good agreement with the data is observed. This is true especially for the pressure-surface boundary layer which is of a rather complex nature because it remains in a transitional state over the full blade length. The influence of various flow phenomena like laminar-turbulent transition and of the boundary conditions (pressure gradient, free-stream turbulence) on the predicted heat transfer rates is discussed.
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Larson, E. D., T. G. Kreutz, and S. Consonni. "Combined Biomass and Black Liquor Gasifier/Gas Turbine Cogeneration at Pulp and Paper Mills." Journal of Engineering for Gas Turbines and Power 121, no. 3 (July 1, 1999): 394–400. http://dx.doi.org/10.1115/1.2818486.
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Kraft pulp and paper mills generate large quantities of black liquor and byproduct biomass suitable for gasification. These fuels are used today for onsite cogeneration of heat and power in boiler/steam turbine systems. Gasification technologies under development would enable these fuels to be used in gas turbines. This paper reports results of detailed full-load performance modeling of pulp-mill cogeneration systems, based on gasifier/gas turbine technologies and, for comparison, on conventional steam-turbine cogeneration technologies. Pressurized, oxygen-blown black liquor gasification, the most advanced of proposed commercial black liquor gasifier designs, is considered, together with three alternative biomass gasifier designs under commercial development (high-pressure air-blown, low-pressure air-blown, and low-pressure indirectly-heated). Heavy-duty industrial gas turbines of the 70-MWe and 25-MWe class are included in the analysis. Results indicate that gasification-based cogeneration with biomass-derived fuels would transform a typical pulp mill into a significant power exporter and would also offer possibilities for net reductions in emissions of carbon dioxide relative to present practice.
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Georgiou, D. P., and J. F. Louis. "The Transpired Turbulent Boundary Layer in Various Pressure Gradients and the Blow-Off Condition." Journal of Engineering for Gas Turbines and Power 107, no. 3 (July 1, 1985): 636–41. http://dx.doi.org/10.1115/1.3239783.
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An experimental study of the reduction in heat transfer to a transpiration-cooled flat surface subjected to pressure gradients (zero, negative, and positive) is presented for flow conditions similar to those encountered in gas turbines. The investigation is carried out for high injection rates and determines the blow-off conditions under which the boundary layer is lifted away from the wall by the transpired coolant. The study was conducted in a hot blow-down wind tunnel facility. The transient nature of the facility ensures that the wall remains isothermal. The Reynolds number, the ratio of the gas to wall temperatures, and the pressure gradient parameters K are chosen to be representative of the conditions found in advanced gas turbines. The effect of the pressure gradient was found to be small. However, a local strong acceleration can reduce the cooling effectiveness. The heat transfer rates or Stanton numbers on a solid surface downstream of a transpiration cooled wall are found to be sensitive to the upstream injection ratio (b) and to the pressure gradient parameter. The data indicate that the ratio of Stanton numbers with and without cooling is nonzero for values of the injection parameters larger than values obtained theoretically by Kutateladze. The predicted value of the critical injection ratio (bcr) determined from this study agrees well with the experimental data of Liepmann and Laufer for a free mixing layer, which is similar to a transpired boundary layer near blow-off as pointed out by Coles.
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Singh, Parminder, SidhNath Singh, and V. Seshadri. "Studies on Stepped Air Ejector Diffusers incorporating Heat Transfer Effects." International Journal of Turbo & Jet-Engines 35, no. 3 (July 26, 2018): 251–63. http://dx.doi.org/10.1515/tjj-2016-0048.
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Abstract Air ejector diffusers are employed in gas turbine exhaust systems to cool the exhaust gases. These diffusers are developed as passive devices, which use the energy of the main flow to entrain the relatively cool ambient air through the annular slot openings. Multiple slot openings are provided along the length of ejector diffusers to lower the temperatures of the exhaust gases. This paper presents results of a 3-D numerical study carried out at a fixed Reynolds Number of 2.5×105 with a corresponding inlet Mach number of about 0.22 on three configurations of a non-circular ejector diffuser having an overall area ratio of 9. The three configurations being investigated are the best diffuser configurations established on the basis of cold flow studies reported in literature. The results are presented in terms of temperature distribution, entrainment mass flux rates and static pressure recovery. The results show that the higher number of slot openings improves cooling in the ejector diffuser as compared to thicker interfaces or inclination at the slot inlet.
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Smith, A. R., J. Klosek, and D. W. Woodward. "Next-Generation Integration Concepts for Air Separation Units and Gas Turbines." Journal of Engineering for Gas Turbines and Power 119, no. 2 (April 1, 1997): 298–304. http://dx.doi.org/10.1115/1.2815575.
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The commercialization of Integrated Gasification Combined Cycle (IGCC) Power has been aided by concepts involving the integration of a cryogenic air separation unit (ASU) with the gas turbine combined-cycle module. Other processes, such as coal-based ironmaking and combined power/industrial gas production facilities, can also benefit from the integration. It is known and now widely accepted that an ASU designed for “elevated pressure” service and optimally integrated with the gas turbine can increase overall IGCC power output, increase overall efficiency, and decrease the net cost of power generation when compared to nonintegrated facilities employing low-pressure ASUs. The specific gas turbine, gasification technology, NOx emission specification, and other site specific factors determine the optimal degree of compressed air and nitrogen stream integration. Continuing advancements in both air separation and gas turbine technologies offer new integration opportunities to improve performance and reduce costs. This paper reviews basic integration principles and describes next-generation concepts based on advanced high pressure ratio gas turbines, Humid Air Turbine (HAT) cycles and integration of compression heat and refrigeration sources from the ASU. Operability issues associated with integration are reviewed and control measures are described for the safe, efficient, and reliable operation of these facilities.
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Xiao, K., J. He, and Z. Feng. "Effects of alternating elliptical chamber on jet impingement heat transfer in vane leading edge under different cross-flow conditions." Aeronautical Journal 125, no. 1291 (April 30, 2021): 1484–500. http://dx.doi.org/10.1017/aer.2021.31.
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ABSTRACTThis paper proposes an alternating elliptical impingement chamber in the leading edge of a gas turbine to restrain the cross flow and enhance the heat transfer, and investigates the detailed flow and heat transfer characteristics. The chamber consists of straight sections and transition sections. Numerical simulations are performed by solving the three-dimensional (3D) steady Reynolds-Averaged Navier–Stokes (RANS) equations with the Shear Stress Transport (SST) k– $\omega$ turbulence model. The influences of alternating the cross section on the impingement flow and heat transfer of the chamber are studied by comparison with a smooth semi-elliptical impingement chamber at a cross-flow Velocity Ratio (VR) of 0.2 and Temperature Ratio (TR) of 1.00 in the primary study. Then, the effects of the cross-flow VR and TR are further investigated. The results reveal that, in the semi-elliptical impingement chamber, the impingement jet is deflected by the cross flow and the heat transfer performance is degraded. However, in the alternating elliptical chamber, the cross flow is transformed to a pair of longitudinal vortices, and the flow direction at the centre of the cross section is parallel to the impingement jet, thus improving the jet penetration ability and enhancing the impingement heat transfer. In addition, the heat transfer in the semi-elliptical chamber degrades rapidly away from the stagnation region, while the longitudinal vortices enhance the heat transfer further, making the heat transfer coefficient distribution more uniform. The Nusselt number decreases with increase of VR and TR for both the semi-elliptical chamber and the alternating elliptical chamber. The alternating elliptical chamber enhances the heat transfer and moves the stagnation point up for all VR and TR, and the heat transfer enhancement is more obvious at high cross-flow velocity ratio.
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Dechamps, P. J., N. Pirard, and Ph Mathieu. "Part-Load Operation of Combined Cycle Plants With and Without Supplementary Firing." Journal of Engineering for Gas Turbines and Power 117, no. 3 (July 1, 1995): 475–83. http://dx.doi.org/10.1115/1.2814120.
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The design point performance of combined cycle power plants has been steadily increasing, because of improvements both in the gas turbine technology and in the heat recovery technology, with multiple pressure heat recovery steam generators. The concern remains, however, that combined cycle power plants, like all installations based on gas turbines, have a rapid performance degradation when the load is reduced. In particular, it is well known that the efficiency degradation of a combined cycle is more rapid than that of a classical steam plant. This paper describes a methodology that can be used to evaluate the part-load performances of combined cycle units. Some examples are presented and discussed, covering multiple pressure arrangements, incorporating supplemental firing and possibly reheat. Some emphasis is put on the additional flexibility offered by the use of supplemental firing, in conjunction with schemes comprising more than one gas turbine per steam turbine. The influence of the gas turbine controls, like the use of variable inlet guide vanes in the compressor control, is also discussed.
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Huang, F. F. "Performance Evaluation of Selected Combustion Gas Turbine Cogeneration Systems Based on First and Second-Law Analysis." Journal of Engineering for Gas Turbines and Power 112, no. 1 (January 1, 1990): 117–21. http://dx.doi.org/10.1115/1.2906465.
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The thermodynamic performance of selected combustion gas turbine cogeneration systems has been studied based on first-law as well as second-law analysis. The effects of the pinch point used in the design of the heat recovery steam generator, and pressure of process steam on fuel-utilization efficiency (first-law efficiency), power-to-heat ratio, and second-law efficiency, are examined. Results for three systems using state-of-the-art industrial gas turbines show clearly that performance evaluation based on first-law efficiency alone is inadequate. Decision makers should find the methodology contained in this paper useful in the comparison and selection of cogeneration systems.
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Sancho-Bastos, Francisco, and Horacio Perez-Blanco. "Cogeneration System Simulation and Control to Meet Simultaneous Power, Heating, and Cooling Demands." Journal of Engineering for Gas Turbines and Power 127, no. 2 (April 1, 2005): 404–9. http://dx.doi.org/10.1115/1.1789993.
Full textAbstract:
Gas turbines are projected to meet increasing power demand throughout the world. Cogeneration plants hold the promise of increased efficiency at acceptable cost. In a general case, a cogen plant could be able to meet power, heating and cooling demands. Yet those demands are normally uncoupled. Control and storage strategies need to be explored to ensure that each independent demand will be met continuously. A dynamic model of a mid-capacity system is developed, including gas and steam turbines, two heat recovery steam generators (HRSG) and an absorption-cooling machine. Controllers are designed using linear quadratic regulators (LQR) to control two turbines and a HRSG with some novelty. It is found that the power required could be generated exclusively with exhaust gases, without a duct burner in the high-pressure HRSG. The strategy calls for fuel and steam flow rate modulation for each turbine. The stability of the controlled system and its performance are studied and simulations for different demand cases are performed.
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Yang, Xing, Zhenping Feng, and Terrence W. Simon. "Conjugate heat transfer modeling of a turbine vane endwall with thermal barrier coatings." Aeronautical Journal 123, no. 1270 (July 19, 2019): 1959–81. http://dx.doi.org/10.1017/aer.2019.56.
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ABSTRACTAdvanced cooling techniques involving internal enhanced heat transfer and external film cooling and thermal barrier coatings (TBCs) are employed for gas turbine hot components to reduce metal temperatures and to extend their lifetime. A deeper understanding of the interaction mechanism of these thermal protection methods and the conjugate thermal behaviours of the turbine parts provides valuable guideline for the design stage. In this study, a conjugate heat transfer model of a turbine vane endwall with internal impingement and external film cooling is constructed to document the effects of TBCs on the overall cooling effectiveness using numerical simulations. Experiments on the same model with no TBCs are performed to validate the computational methods. Round and crater holes due to the inclusion of TBCs are investigated as well to address how film-cooling configurations affect the aero-thermal performance of the endwall. Results show that the TBCs have a profound effect in reducing the endwall metal temperatures for both cases. The TBC thermal protection for the endwall is shown to be more significant than the effect of increasing coolant mass flow rate. Although the crater holes have better film cooling performance than the traditional round holes, a slight decrement of overall cooling effectiveness is found for the crater configuration due to more endwall metal surfaces directly exposed to external mainstream flows. Energy loss coefficients at the vane passage exit show a relevant negative impact of adding TBCs on the cascade aerodynamic performance, particularly for the round hole case.
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Mokhov, K. Y., A. Y. Kudryavtsev, O. V. Voronkov, E. B. Voronina, S. V. Sukhov, A. A. Ryabov, Y. N. Zhurenkov, A. V. Soloveva, and A. V. Grigoriev. "Numerical Simulation of Fire Resistance Test for Gas Turbine Component Using Coupled CFD/FEM Approach." International Journal of Aerospace Engineering 2020 (October 29, 2020): 1–7. http://dx.doi.org/10.1155/2020/8867708.
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The article presents the implementation of CFD/FEM approach for real oil tank of the gas turbine engine for the purposes of prediction of the component behavior under the local impact of a burner jet. The model takes into account heat and mass transfer problems as well as strength problems that are solved using a one way coupled fluid-structure interaction method. Results of the blind test simulation are compared and show good agreement with available experimental data.
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De Lucia, M., R. Bronconi, and E. Carnevale. "Performance and Economic Enhancement of Cogeneration Gas Turbines Through Compressor Inlet Air Cooling." Journal of Engineering for Gas Turbines and Power 116, no. 2 (April 1, 1994): 360–65. http://dx.doi.org/10.1115/1.2906828.
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Gas turbine air cooling systems serve to raise performance to peak power levels during the hot months when high atmospheric temperatures cause reductions in net power output. This work describes the technical and economic advantages of providing a compressor inlet air cooling system to increase the gas turbine’s power rating and reduce its heat rate. The pros and cons of state-of-the-art cooling technologies, i.e., absorption and compression refrigeration, with and without thermal energy storage, were examined in order to select the most suitable cooling solution. Heavy-duty gas turbine cogeneration systems with and without absorption units were modeled, as well as various industrial sectors, i.e., paper and pulp, pharmaceuticals, food processing, textiles, tanning, and building materials. The ambient temperature variations were modeled so the effects of climate could be accounted for in the simulation. The results validated the advantages of gas turbine cogeneration with absorption air cooling as compared to other systems without air cooling.
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Green, A. E. S., and J. P. Mullin. "Feedstock Blending Studies With Laboratory Indirectly Heated Gasifiers." Journal of Engineering for Gas Turbines and Power 121, no. 4 (October 1, 1999): 593–99. http://dx.doi.org/10.1115/1.2818513.
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To support the further-development of indirectly heated gasifiers intended to provide fuels for advanced gas turbines, several indirectly heated laboratory gasifiers were constructed. During many comparative tests, advantages and problems with each system were observed. The most useful systems make use of laboratory tube furnaces in conjunction with temperature, time, and pressure or volume yield measuring systems and a gas chromatograph with a thermal conductivity detector. In this paper, high temperature pyrolysis results obtained with the latest system are presented. Contrasting feedstocks suitable for commercial systems separately or in blends are used. Yield versus time measurements are used to determine relevant rate constants and outputs. Since the rate constants are mainly reflective of heat transfer effects, cylindrical dowel sticks of varying radii were volatilized. The data set leads to an analytic heat transfer model that considers the hemicellulose, cellulose, and lignin components of the dowels. Also developed from the dowel experiments is an approximate procedure for estimating the proportionate releases of CO, CO2, CH4, and H2 for any type of biomass whose component proportions are known.
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Dunn, M. G. "Turbine Heat Flux Measurements: Influence of Slot Injection on Vane Trailing Edge Heat Transfer and Influence of Rotor on Vane Heat Transfer." Journal of Engineering for Gas Turbines and Power 107, no. 1 (January 1, 1985): 76–83. http://dx.doi.org/10.1115/1.3239700.
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This paper describes the measurement of heat flux distributions obtained for a Garrett TFE 731-2 hp turbine. Measurements were obtained for a full turbine both with and without injection and for the nozzle guide vanes with and without a rotor. A shock tube is used as a short-duration source of heated air and miniature thin-film gages are used to obtain the heat flux measurements. Results are presented for values of the blowing parameter (ρcVc/ρ∞V∞)at SLOT, in the range of 0.8–1.3. The injection gas (air) as a percentage of turbine weight flow, Wc/Wo, was in the range of 2.1–3.5 percent. A comparison is presented between results obtained with the rotor operating at 100 percent of corrected speed and those obtained with the rotor replaced by a row of flow straighteners. The results suggest that: (i) the reduction of heat flux due to injection is a function of the blowing parameter, the temperature ratio, and the physical location relative to the tip or hub endwall and (ii) the presence of the rotor has a significant affect on the vane trailing edge Stanton number, increasing it by 15 to 25 percent. The vane leading edge and midchord regions were generally unaffected.
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Kolp, D. A., W. M. Flye, and H. A. Guidotti. "Advantages of Air Conditioning and Supercharging an LM6000 Gas Turbine Inlet." Journal of Engineering for Gas Turbines and Power 117, no. 3 (July 1, 1995): 513–27. http://dx.doi.org/10.1115/1.2814125.
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Of all the external factors affecting a gas turbine, inlet pressure and temperature have the greatest impact on performance. The effect of inlet temperature variations is especially pronounced in the new generation of high-efficiency gas turbines typified by the 40 MW GE LM6000. A reduction of 50°F (28°C) in inlet temperature can result in a 30 percent increase in power and a 4.5 percent improvement in heat rate. An elevation increase to 5000 ft (1524 m) above sea level decreases turbine output 17 percent; conversely supercharging can increase output more than 20 percent. This paper addresses various means of heating, cooling and supercharging LM6000 inlet air. An economic model is developed and sample cases are cited to illustrate the optimization of gas turbine inlet systems, taking into account site conditions, incremental equipment cost and subsequent performance enhancement.
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Bailey, J. C., J. Intile, T. F. Fric, A. K. Tolpadi, N. V. Nirmalan, and R. S. Bunker. "Experimental and Numerical Study of Heat Transfer in a Gas Turbine Combustor Liner." Journal of Engineering for Gas Turbines and Power 125, no. 4 (October 1, 2003): 994–1002. http://dx.doi.org/10.1115/1.1615256.
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Experiments and numerical simulations were conducted to understand the heat transfer characteristics of a stationary gas turbine combustor liner cooled by impingement jets and cross flow between the liner and sleeve. Heat transfer was also aided by trip-strip turbulators on the outside of the liner and in the flowsleeve downstream of the jets. The study was aimed at enhancing heat transfer and prolonging the life of the combustor liner components. The combustor liner and flow sleeve were simulated using a flat-plate rig. The geometry has been scaled from actual combustion geometry except for the curvature. The jet Reynolds number and the mass-velocity ratios between the jet and cross flow in the rig were matched with the corresponding combustor conditions. A steady-state liquid crystal technique was used to measure spatially resolved heat transfer coefficients for the geometric and flow conditions mentioned above. The heat transfer was measured both in the impingement region as well as over the turbulators. A numerical model of the combustor test rig was created that included the impingement holes and the turbulators. Using CFD, the flow distribution within the flow sleeve and the heat transfer coefficients on the liner were both predicted. Calculations were made by varying the turbulence models, numerical schemes, and the geometrical mesh. The results obtained were compared to the experimental data and recommendations have been made with regard to the best modeling approach for such liner-flow sleeve configurations.
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Camci, C., and T. Arts. "Short-Duration Measurements and Numerical Simulation of Heat Transfer Along the Suction Side of a Film-Cooled Gas Turbine Blade." Journal of Engineering for Gas Turbines and Power 107, no. 4 (October 1, 1985): 991–97. http://dx.doi.org/10.1115/1.3239846.
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This paper deals with an experimental investigation of heat transfer across the suction side of a high-pressure, film-cooled gas turbine blade and with an attempt to numerically predict this quantity both with and without film cooling. The measurements were performed in the VKI isentropic compression tube facility under well-simulated gas turbine conditions. Data measured in a stationary frame, with and without film cooling, are presented. The predictions of convective heat transfer, including streamwise curvature effects, are compared with the measurements. A new approach to determine the augmented mixing lengths near the ejection holes on a highly convex wall is discussed and numerical results agree well with experimentally determined heat transfer coefficients in the presence of film cooling.
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Bhargava, R. K., C. B. Meher-Homji, M. A. Chaker, M. Bianchi, F. Melino, A. Peretto, and S. Ingistov. "Gas Turbine Fogging Technology: A State-of-the-Art Review—Part II: Overspray Fogging—Analytical and Experimental Aspects." Journal of Engineering for Gas Turbines and Power 129, no. 2 (February 1, 2006): 454–60. http://dx.doi.org/10.1115/1.2364004.
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The strong influence of ambient temperature on the output and heat rate on a gas turbine has popularized the application of inlet fogging and overspray for power augmentation. One of the main advantages of overspray fogging is that it enhances power output as a result of decrease in compression work associated with the continuous evaporation of water within the compressor due to fog intercooling. A comprehensive review on the current understanding of the analytical and experimental aspects of overspray fogging technology as applied to gas turbines is presented in this paper.
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Bowen, T. L., D. P. Guimond, and R. K. Muench. "Experimental Investigation of Gas Turbine Recuperator Fouling." Journal of Engineering for Gas Turbines and Power 109, no. 3 (July 1, 1987): 249–56. http://dx.doi.org/10.1115/1.3240032.
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This paper discusses an experimental investigation of recuperator fouling currently underway at the David Taylor Naval Ship Research and Development Center. The overall approach involves testing different heat exchangers in the exhaust gas stream of a gas turbine. The two heat exchangers initially tested were the plate-fin type and differed in the gas-side heat transfer surface geometry. Primary surface heat exchangers are being considered for future tests also. Test conditions are defined such that the critical part of full-scale recuperators (i.e., the colder end of the gas passages) is simulated in the small test heat exchangers. The composition of the gas stream is measured to determine amounts of gaseous, particulate, and condensible hydrocarbon emissions. Fuel samples taken during each test are analyzed. The test heat exchangers are specially constructed to allow inspection and measurement of the fouling film inside the unit following each test. The temperature distribution inside the test exchanger is measured, as well as air and gas inlet and exit temperatures. Measurements of fouling film thickness are made using an optical microscope and photographs of fouling deposits were taken. The early results obtained from fouling tests conducted with the first heat exchanger are discussed. Tests were also conducted to demonstrate a fouling removal technique.
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Kusˇtrin, I., and M. Tuma. "The Effectiveness of Heat Transfer From Flue Gases to Ammonia-Water Mixtures." Journal of Engineering for Gas Turbines and Power 116, no. 1 (January 1, 1994): 63–67. http://dx.doi.org/10.1115/1.2906810.
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The paper deals with the theoretical comparison of the heat transfer process from the exhaust gases of a gas turbine to pure water or to an ammonia-water mixture in the single-pressure, nonreheat, heat recovery boiler. The main difference is the variable-temperature boiling of the mixture, which improves the match of the temperature profiles in comparison to the match obtained by the use of pure water. The result is smaller loss of energy and exergy. Thermal and exergetic efficiencies are improved, which means better use of the primary heat source, i.e., the fuel of the gas turbine. At the end of the paper the usefulness of the ammonia-water mixture at higher inlet (above 500°C) and outlet (above 180°C) gas temperatures is analyzed. The main advantages of the mixture disappear under such conditions.
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Baklanov, A. V., and A. V. Gimbitskii. "Study of Heat Transfer from the Shell of Gas Turbine Plant and Methods of Its Thermal Protection." Russian Aeronautics 62, no. 3 (July 2019): 463–68. http://dx.doi.org/10.3103/s1068799819030140.
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Wittmann, Tim, Sebastian Lück, Christoph Bode, and Jens Friedrichs. "Modelling the Condensation Phenomena within the Radial Turbine of a Fuel Cell Turbocharger." International Journal of Turbomachinery, Propulsion and Power 6, no. 3 (July 8, 2021): 23. http://dx.doi.org/10.3390/ijtpp6030023.
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Radial turbines used in automotive fuel cell turbochargers operate with humid air. The gas expansion in the turbine causes droplets to form, which then grow through condensation. The associated release of latent heat and decrease in the gaseous mass flow strongly influence the thermodynamics of the turbine. This study aims to investigate these phenomena. For this purpose, the classical nucleation theory and Young’s growth law are integrated into a Euler–Lagrange approach. The main advantages of this approach are the calculation of individual droplet trajectories and a full resolution of the droplet spectrum. The results indicate an onset of nucleation at the blade tip and in the tip gap, followed by nucleation over the entire blade span, depending on the humidity at the turbine inlet. With a saturated turbine inflow, condensation causes the outlet temperature to rise to almost the same level as at the inlet. In addition, condensation losses reduce the efficiency and the latent heat released by condensation leads to significant thermal throttling.
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Solomon, P. R., M. A. Serio, J. E. Cosgrove, D. S. Pines, Y. Zhao, R. C. Buggeln, and S. J. Shamroth. "A Coal-Fired Heat Exchanger for an Externally Fired Gas Turbine." Journal of Engineering for Gas Turbines and Power 118, no. 1 (January 1, 1996): 22–31. http://dx.doi.org/10.1115/1.2816545.
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Significant improvements in efficiency for electricity generation from coal can be achieved by cycles that employ a high-temperature, highly recuperative gas turbine topping cycle. The principal difficulty of employing a gas turbine in a coal-fired power generation system is the possible erosion and corrosion of the high-temperature rotating gas turbine components caused by the coal’s inorganic and organically bound constituents (ash, sulfur, and alkali metals). One route to overcome this problem is the development of an externally fired gas turbine system employing a coal fired heat exchanger. The solution discussed in this paper is the design of a Radiatively Enhanced, Aerodynamically Cleaned Heat-Exchanger (REACH-Exchanger). The REACH-Exchanger is fired by radiative and convective heat transfer from a moderately clean fuel stream and radiative heat transfer from the flame of a much larger uncleaned fuel stream, which supplies most of the heat. The approach is to utilize the best ceramic technology available for high-temperature parts of the REACH-Exchanger and to shield the high-temperature surfaces from interaction with coal minerals by employing clean combustion gases that sweep the tube surface exposed to the coal flame. This paper presents a combined experimental/computational study to assess the viability of the REACH-Exchanger concept. Experimental results indicated that the REACH-Exchanger can be effectively fired using radiation from the coal flame. Both computation and experiments indicate that the ceramic heat exchanger can be aerodynamically protected by a tertiary stream with an acceptably low flow rate.
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Kluka, J. A., and D. G. Wilson. "Low-Leakage Modular Regenerators for Gas-Turbine Engines." Journal of Engineering for Gas Turbines and Power 120, no. 2 (April 1, 1998): 358–62. http://dx.doi.org/10.1115/1.2818130.
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One of the significant problems plaguing regenerator designs is seal leakage resulting in a reduction of thermal efficiency. This paper describes the preliminary design and analysis of a new regenerative heat-exchanger concept, called a modular regenerator, that promises to provide improved seal-leakage performance. The modular regenerator concept consists of a ceramic-honeycomb matrix discretized into rectangular blocks, called modules. Separating the matrix into modules substantially reduces the transverse sealing lengths and substantially increases the longitudinal sealing lengths as compared with typical rotary designs. Potential applications can range from small gas-turbine engines for automotive applications to large stationary gas turbines for industrial power generation. Descriptions of two types of modular regenerators are presented including sealing concepts. Results of seal leakage analysis for typical modular regenerators sized for a small gas-turbine engine (120 kW) predict leakage rates under one percent for most seal-clearance heights.
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Consonni, S., and E. D. Larson. "Biomass-Gasifier/Aeroderivative Gas Turbine Combined Cycles: Part A—Technologies and Performance Modeling." Journal of Engineering for Gas Turbines and Power 118, no. 3 (July 1, 1996): 507–15. http://dx.doi.org/10.1115/1.2816677.
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Gas turbines fueled by integrated biomass gasifiers are a promising option for base load electricity generation from a renewable resource. Aeroderivative turbines, which are characterized by high efficiencies at smaller scales, are of special interest because transportation costs for biomass constrain biomass conversion facilities to relatively modest scales. Commercial development activities and major technological issues associated with biomass integrated-gasifier/gas turbine (BIG/GT) combined cycle power generation are reviewed in Part A of this two-part paper. Also, the computational model and the assumptions used to predict the overall performance of alternative BIG/GT cycles are outlined. The model evaluates appropriate value of key parameters (turbomachinery efficiencies, gas turbine cooling flows, steam production in the heat recovery steam generator, etc.) and then carries out energy, mass, and chemical species balances for each plant component, with iterations to insure whole-plant consistency. Part B of the paper presents detailed comparisons of the predicted performance of systems now being proposed for commercial installation in the 25–30 MWe power output range, as well as predictions for advanced combined cycle configurations (including with intercooling) with outputs from 22 to 75 MWe. Finally, an economic assessment is presented, based on preliminary capital cost estimates for BIG/GT combined cycles.