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1
Rodgers, C. « Impingement Starting and Power Boosting of Small Gas Turbines ». Journal of Engineering for Gas Turbines and Power 107, no 4 (1 octobre 1985) : 821–27. http://dx.doi.org/10.1115/1.3239817.
Texte intégralRésumé :
The technology of high-pressure air or hot-gas impingement from stationary shroud supplementary nozzles onto radial outflow compressors and radial inflow turbines to permit rapid gas turbine starting or power boosting is discussed. Data are presented on the equivalent turbine component performance for convergent/divergent shroud impingement nozzles, which reveal the sensitivity of nozzle velocity coefficient with Mach number and turbine efficiency with impingement nozzle admission arc. Compressor and turbine matching is addressed in the transient turbine start mode with the possibility of operating these components in braking or reverse flow regimes when impingement flow rates exceed design.
2
Karstensen, K. W., et J. O. Wiggins. « A Variable-Geometry Power Turbine for Marine Gas Turbines ». Journal of Turbomachinery 112, no 2 (1 avril 1990) : 165–74. http://dx.doi.org/10.1115/1.2927629.
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Gas turbines have been accepted in naval surface ship applications, and considerable effort has been made to improve their fuel consumption, particularly at part-load operation. This is an important parameter for shipboard engines because both propulsion and electrical-generator engines spend most of their lives operating at off-design power. An effective way to improve part-load efficiency of recuperated gas turbines is by using a variable power turbine nozzle. This paper discusses the successful use of variable power turbine nozzles in several applications in a family of engines developed for vehicular, industrial, and marine use. These engines incorporate a variable power turbine nozzle and primary surface recuperator to yield specific fuel consumption that rivals that of medium speed diesels. The paper concentrates on the experience with the variable nozzle, tracing its derivation from an existing fixed vane nozzle and its use across a wide range of engine sizes and applications. Emphasis is placed on its potential in marine propulsion and auxiliary gas turbines.
3
Chaker, Mustapha, Cyrus B. Meher-Homji et Thomas Mee. « Inlet Fogging of Gas Turbine Engines—Part II : Fog Droplet Sizing Analysis, Nozzle Types, Measurement, and Testing ». Journal of Engineering for Gas Turbines and Power 126, no 3 (1 juillet 2004) : 559–70. http://dx.doi.org/10.1115/1.1712982.
Texte intégralRésumé :
The inlet fogging of gas turbine engines for power augmentation has seen increasing application over the past decade yet not a single technical paper treating the physics and engineering of the fogging process, droplet size measurement, droplet kinetics, or the duct behavior of droplets, from a gas turbine perspective, is available. This paper provides the results of extensive experimental and theoretical studies conducted over several years, coupled with practical aspects learned in the implementation of nearly 500 inlet fogging systems on gas turbines ranging in power from 5 to 250 MW. Part II of the paper treats the practical aspects of fog nozzle droplet sizing, measurement and testing presenting the information from a gas turbine fogging perspective. This paper describes the different measurement techniques available, covers design aspects of nozzles, provides experimental data on different nozzles, and provides recommendations for a standardized nozzle testing method for gas turbine inlet air fogging.
4
Kriukov, Aleksei Alekseevich. « Influence of nozzle inclination angle on velocity coefficient of inflow turbine with partial blading of runner ». Vestnik of Astrakhan State Technical University. Series : Marine engineering and technologies 2023, no 1 (28 février 2023) : 23–29. http://dx.doi.org/10.24143/2073-1574-2023-1-23-29.
Texte intégralRésumé :
The paper considers a numerical experiment with three groups of low-consuming inflow turbines with partial blading of the runner. Geometrical models of the turbine stages with partial blading of the runner at different angles of the nozzle inclination have been developed. The inflow turbine stages with partial blading of the runner are investigated. The efficiency and speed coefficient of the inflow turbine nozzles are calculated. There has been carried out numerical modeling of the working fluid flow by using the computational gas dynamics elements. Pick values of the nozzle apparatus velocity coefficient and the turbine stage efficiency are defined. Geometric models of the turbine stages with different nozzle inclination angles are developed, the boundary conditions of the experiment are determined, and the experiment results are analyzed and shown. There are given the dependence graphs of the nozzle velocity coefficient and the efficiency of a low-consuming inflow turbine stage. Comparative analysis of the nozzle velocity coefficient and the efficiency of three turbine stages with different inclination angles of the nozzles in the nozzle apparatus has been carried out. Conclusions are drawn about further procedures on improving the flow part of the runner to increase the efficiency of the stage.
5
Shen, J. J. S., V. C. Ting et E. H. Jones. « Application of Sonic Nozzles in Field Calibration of Natural Gas Flows ». Journal of Energy Resources Technology 111, no 4 (1 décembre 1989) : 205–13. http://dx.doi.org/10.1115/1.3231425.
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This paper presents Chevron Oil Field Research Company’s operating experience using the sonic nozzle as a proving device for measuring natural gas flows in field tests. The nozzle reference flow rate was used for calibrating orifice, turbine, and vortex meters in three tests with a pipeline quality gas and an unprocessed natural gas as the working fluid. For pipeline gas, the field calibration results show good agreement between the sonic nozzle reference and a turbine meter while the accuracy of orifice metering is size dependent. The 4-in. (102-mm) orifice meter flow rates agree well with the nozzle reference, but the 16-in. (406-mm) orifice flow measurements are up to 2 percent lower. Deviations between the test meters and the sonic nozzles are generally larger for the unprocessed gas. These field projects demonstrate that sonic nozzles can be operated successfully as a prover for processed natural gas, while more work is needed to study the critical flow in nozzles for unprocessed natural gas.
6
Sanaye, Sepehr, et Salahadin Hosseini. « Off-design performance improvement of twin-shaft gas turbine by variable geometry turbine and compressor besides fuel control ». Proceedings of the Institution of Mechanical Engineers, Part A : Journal of Power and Energy 234, no 7 (3 décembre 2019) : 957–80. http://dx.doi.org/10.1177/0957650919887888.
Texte intégralRésumé :
A novel procedure for finding the optimum values of design parameters of industrial twin-shaft gas turbines at various ambient temperatures is presented here. This paper focuses on being off design due to various ambient temperatures. The gas turbine modeling is performed by applying compressor and turbine characteristic maps and using thermodynamic matching method. The gas turbine power output is selected as an objective function in optimization procedure with genetic algorithm. Design parameters are compressor inlet guide vane angle, turbine exit temperature, and power turbine inlet nozzle guide vane angle. The novel constrains in optimization are compressor surge margin and turbine blade life cycle. A trained neural network is used for life cycle estimation of high pressure (gas generator) turbine blades. Results for optimum values for nozzle guide vane/inlet guide vane (23°/27°–27°/6°) in ambient temperature range of 25–45 ℃ provided higher net power output (3–4.3%) and more secured compressor surge margin in comparison with that for gas turbines control by turbine exit temperature. Gas turbines thermal efficiency also increased from 0.09 to 0.34% (while the gas generator turbine first rotor blade creep life cycle was kept almost constant about 40,000 h). Meanwhile, the averaged values for turbine exit temperature/turbine inlet temperature changed from 831.2/1475 to 823/1471°K, respectively, which shows about 1% decrease in turbine exit temperature and 0.3% decrease in turbine inlet temperature.
7
Kravchuk, Yu, et Т. Tatarchuk. « Methods of increasing the reliability of turbine elements ». Innovative Materials and Technologies in Metallurgy and Mechanical Engineering, no 2 (18 mars 2021) : 57–65. http://dx.doi.org/10.15588/1607-6885-2020-2-8.
Texte intégralRésumé :
The purpose of the work. Statistical and experimental analysis of coating methods on the turbine nozzle apparatus to increase the temperature regime.
Research methods. Calculation method of finite elements, experimental.
The results obtained. Studies have shown that the use of thermally protective coatings TZP thickness of 250 мm with a thermal conductivity of 1 W / mK on the two steps of the turbine can implement one of two possibilities:
- at constant operating temperature of the blade material to increase the temperature of the gas in front of the turbine by about 100 °C, which will increase efficiency and fuel savings by more than 13 %;- without changing the temperature of the gas in front of the turbine - to increase the durability of the blades by about 4 times, due to a decrease in their operating temperature. The analysis of two methods of drawing TZP was carried out, in the work the estimation of a temperature condition of the nozzle device (CA) of the turbine of a high pressure of the engine, decrease in its temperature due to drawing TZP and increase of its resource is carried out. The problem was solved by applying TZP on the blades of the nozzle apparatus. The analysis of two methods of drawing TZP was carried out, the estimation of a temperature condition of the nozzle device (CA) of the turbine of high pressure of the engine, decrease in its temperature due to drawing TZP and increase of its resource is carried out.
Scientific novelty. The problem of creating efficient, economical and reliable gas turbines is the most difficult among the many problems that arise in the development of gas turbine construction. Important elements of turbines are working and nozzle blades, the material and design of which determine the allowable gas temperature in front of the turbine and thus directly affect the technical and economic performance of the gas turbine engine.
Practical value. The obtained results are important for the further development of aircraft engine construction, due to the application of TZP achieved an increase in the resource of CA from 40,000 hours to 67,000 hours.
8
Myers, G. D., J. P. Armstrong, C. D. White, S. Clouser et R. J. Harvey. « Development of an Innovative High-Temperature Gas Turbine Fuel Nozzle ». Journal of Engineering for Gas Turbines and Power 114, no 2 (1 avril 1992) : 401–8. http://dx.doi.org/10.1115/1.2906605.
Texte intégralRésumé :
The objective of the innovative high-temperature fuel nozzle program was to design, fabricate, and test propulsion engine fuel nozzles capable of performance despite extreme fuel and air inlet temperatures. Although a variety of both passive and active methods for reducing fuel wetted-surface temperatures were studied, simple thermal barriers were found to offer the best combination of operability, cycle flexibility, and performance. A separate nozzle material study examined several nonmetallics and coating schemes for evidence of passivating or catalytic tendencies. Two pilotless airblast nozzles were developed by employing finite-element modeling to optimize thermal barriers in the stem and tip. Operability of these prototypes was compared to a current state-of-the art piloted, prefliming airblast nozzle, both on the spray bench and through testing in a can-type combustor. The three nozzles were then equipped with internal thermocouples and operated at 1600°F air inlet temperature while injecting marine diesel fuel heated to 350°F. Measured and predicted internal temperatures as a function of fuel flow rate were compared. Results show that the thermal barrier systems dramatically reduced wetted-surface temperatures and the potential for coke fouling, even in an extreme environment.
9
Richards, G. A., et M. C. Janus. « Characterization of Oscillations During Premix Gas Turbine Combustion ». Journal of Engineering for Gas Turbines and Power 120, no 2 (1 avril 1998) : 294–302. http://dx.doi.org/10.1115/1.2818120.
Texte intégralRésumé :
The use of premix combustion in stationary gas turbines can produce very low levels of Nox emissions. This benefit is widely recognized, but turbine developers routinely encounter problems with combustion oscillations during the testing of new premix combustors. Because of the associated pressure fluctuations, combustion oscillations must be eliminated in a final combustor design. Eliminating these oscillations is often time-consuming and costly because there is no single approach to solve an oscillation problem. Previous investigations of combustion stability have focused on rocket applications, industrial furnaces, and some aeroengine gas turbines. Comparatively little published data is available for premixed combustion at conditions typical of an industrial gas turbine. In this paper, we report experimental observations of oscillations produced by a fuel nozzle typical of industrial gas turbines. Tests are conducted in a specially designed combustor capable of providing the acoustic feedback needed to study oscillations. Tests results are presented for pressure up to 10 atmospheres, with inlet air temperatures up to 588 K (600 F) burning natural gas fuel. Based on theoretical considerations, it is expected that oscillations can be characterized by a nozzle reference velocity, with operating pressure playing a smaller role. This expectation is compared to observed data that shows both the benefits and limitations of characterizing the combustor oscillating behavior in terms of a reference velocity rather than other engine operating parameters. This approach to characterizing oscillations is then used to evaluate how geometric changes to the fuel nozzle will affect the boundary between stable and oscillating combustion.
10
Придорожный, Роман Петрович, Александр Викторович Шереметьев et Анатолий Павлович Зиньковский. « ВЛИЯНИЕ ПОЛЗУЧЕСТИ МАТЕРИАЛА НА РАБОТОСПОСОБНОСТЬ ЛОПАТОК СОПЛОВОГО АППАРАТА ТУРБИНЫ ВЫСОКОГО ДАВЛЕНИЯ ». Aerospace technic and technology, no 7 (31 août 2020) : 41–46. http://dx.doi.org/10.32620/aktt.2020.7.06.
Texte intégralRésumé :
The creation of aircraft gas turbine engines that meet modern requirements for the resource, especially its hot part, requires not only more advanced design methods but also an analysis of operability and damageability during the resource to find reserves aimed at improving reliability. One of the most complex and heat-stressed components of a modern gas turbine engine is the nozzle vanes of a high-pressure turbine, directly perceiving the high temperature of the gas at the exit of the combustion chamber and having an advanced convection-film cooling system. The service life nozzle vanes of modern aviation gas turbine engines can be tens of thousands of hours. At the same time, the maximum operating mode can reach only a few hundred hours. It is believed that damage to nozzle vanes on an engine occurs mainly in hot climatic zones. Nevertheless, as the analysis of computational studies for modern aviation gas turbine engines shows, such statements are erroneous. The direct consequence of the action of elevated temperatures and high thermal stresses is the creep of the material. A computational study of the effect of creep of the material of the nozzle vanes of a high-pressure turbine under various operating conditions of the engine on their operability was carried. It is shown that with increasing flight altitude the working temperature of the nozzle vane begins to increase, and creep processes are accelerated for all climatic zones of operation. Since with increasing flight altitude, the temperature difference for different climatic zones gradually decreases, at high altitudes, where the temperature in different climatic zones differs slightly, stress relaxation processes proceed identically. In this case, with an increase in temperature, creep processes proceed faster, and the stress level to which stress relaxation occurs becomes lower. Thus, with increasing flight altitude, damage in cold conditions approaches that under normal and hot conditions, and at high altitudes, it can even be higher. The regularities of the influence of climatic conditions and flight altitude on the strength of the nozzle vanes of high-pressure turbines and their operability are established, based on which the need to take into account the operating time of the engine in various climatic conditions when determining the service life of nozzle vanes is shown.
11
Kim, Jonghyun, et Jungsoo Park. « Conceptual Approach to Combustor Nozzle and Reformer Characteristics for Micro-Gas Turbine with an On-Board Reforming System : A Novel Thermal and Low Emission Cycle ». Sustainability 12, no 24 (17 décembre 2020) : 10558. http://dx.doi.org/10.3390/su122410558.
Texte intégralRésumé :
In order to implement moderate or intensive low oxygen dilution (MILD) combustion, it is necessary to extend the flame stability and operating range. In the present study, the conceptual designs of a combustor single nozzle and reformer were numerically suggested for a micro-gas turbine with an on-board reformer. The target micro-gas turbine achieved a thermal power of 150 kW and a turbine inlet temperature (TIT) of 1200 K. Studies on a nozzle and reformer applying an open-loop concept have been separately conducted. For the nozzle concept, a single down-scaled nozzle was applied based on a reference nozzle for a heavy-duty gas turbine. The nozzle can achieve a good mixture with a high swirl with a splined swirl curve lower NOx emissions and smaller pressure drop in the combustor. The concept of the non-catalytic partial-oxidation reforming reformate was designed using the combustor outlet temperature (COT) of the exhaust gas. Feasible hydrogen yields were mapped through the reformer. Based on the hydrogen yields from the reformer, hydrogen was added to the nozzle to investigate its combustion behavior. By increasing the hydrogen addition and decreasing the O2 fraction, the OH concentrations were decreased and widely distributed similar to the fundamental characteristics of MILD combustion.
12
Tsuchiya, T., Y. Furuse, S. Yoshino, R. Chikami, Y. Tsukuda et M. Mori. « Development of Air-Cooled Ceramic Nozzles for a Power-Generating Gas Turbine ». Journal of Engineering for Gas Turbines and Power 118, no 4 (1 octobre 1996) : 717–23. http://dx.doi.org/10.1115/1.2816986.
Texte intégralRésumé :
The development of air-cooled ceramic nozzle vanes for a power-generating gas turbine has been reported. To make up the limited temperature resistance of present ceramic materials, the utilization of a small amount of cooling air has been studied for the first-stage nozzle vanes of a 1500°C class gas turbine. A series of cascade tests were carried out for the designed air-cooled Si3N4 nozzle vanes under 6 atm and 1500°C conditions. It was confirmed that the maximum ceramic temperature can be maintained below 1300°C by a small amount of cooling air. In spite of the increased thermal stresses from local cooling, all Si3N4 nozzle vanes survived the cascade tests, including both steady-state and transients of emergency shutdown. The potential for an air-cooled ceramic nozzle was demonstrated for a 1500°C class gas turbine application.
13
Fulara, Szymon, Maciej Chmielewski et Marian Gieras. « Experimental research of the small gas turbine with variable area nozzle ». Proceedings of the Institution of Mechanical Engineers, Part G : Journal of Aerospace Engineering 233, no 15 (4 juin 2019) : 5650–59. http://dx.doi.org/10.1177/0954410019853977.
Texte intégralRésumé :
The main aim of this article is to present the experimental data of the operating parameters and emissions obtained in a small gas turbine equipped with a variable area nozzle system. The variable area nozzle is proposed as a means of improving turbine efficiency, which has been a popular trend in recent development of gas turbine engines. Based on turbine vane twisting, the proposed variable area nozzle system was developed and implemented in GTM-120 small gas turbine. The concept was experimentally investigated on the engine test bench and engine working parameters were accurately measured. Experimental research shows that significant improvement of engine specific fuel consumption (up to 4%) and specific thrust (up to 5%) has been achieved. Additionally, reduction in CO emissions (up to 64%), NO emissions (up to 7%) and NO2 emissions (up to 53%) has been noted. Experimental research results were compared with analytical engine model showing moderate, qualitative agreement between the experimental data and model outputs. Main advantages of variable area nozzle system and design challenges of the proposed concept are discussed in the article summary.
14
Rizk, N. K., J. S. Chin et M. K. Razdan. « Modeling of Gas Turbine Fuel Nozzle Spray ». Journal of Engineering for Gas Turbines and Power 119, no 1 (1 janvier 1997) : 34–44. http://dx.doi.org/10.1115/1.2815559.
Texte intégralRésumé :
Satisfactory performance of the gas turbine combustor relies on the careful design of various components, particularly the fuel injector. It is, therefore, essential to establish a fundamental basis for fuel injection modeling that involves various atomization processes. A two-dimensional fuel injection model has been formulated to simulate the airflow within and downstream of the atomizer and address the formation and breakup of the liquid sheet formed at the atomizer exit. The sheet breakup under the effects of airblast, fuel pressure, or the combined atomization mode of the airassist type is considered in the calculation. The model accounts for secondary breakup of drops and the stochastic Lagrangian treatment of spray. The calculation of spray evaporation addresses both droplet heat-up and steady-state mechanisms, and fuel vapor concentration is based on the partial pressure concept. An enhanced evaporation model has been developed that accounts for multicomponent, finite mass diffusivity and conductivity effects, and addresses near-critical evaporation. The presents investigation involved predictions of flow and spray characteristics of two distinctively different fuel atomizers under both nonreacting and reacting conditions. The predictions of the continuous phase velocity components and the spray mean drop sizes agree well with the detailed measurements obtained for the two atomizers, which indicates the model accounts for key aspects of atomization. The model also provides insight into ligament formation and breakup at the atomizer exit and the initial drop sizes formed in the atomizer near field region where measurements are difficult to obtain. The calculations of the reacting spray show the fuel-rich region occupied most of the spray volume with two-peak radial gas temperature profiles. The results also provided local concentrations of unburned hydrocarbon (UHC) and carbon monoxide (CO) in atomizer flowfield, information that could support the effort to reduce emission levels of gas turbine combustors.
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Aksoy, S., C. Anekwe, J. O'Connor et D. Schwartz. « Cyclic structural analysis of gas turbine nozzle ». Computers & ; Structures 27, no 1 (janvier 1987) : 165–70. http://dx.doi.org/10.1016/0045-7949(87)90191-x.
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Mazur, Z., A. Hernandez-Rossette, R. Garcia-Illescas et A. Luna-Ramirez. « Failure analysis of a gas turbine nozzle ». Engineering Failure Analysis 15, no 7 (octobre 2008) : 913–21. http://dx.doi.org/10.1016/j.engfailanal.2007.10.009.
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Lytvynenko, Oksana, et Irina Myhaylova. « Selection of the Design of a Contact Condenser of a Gas-Steam Plant with Steam Injection into the Combustion Chamber ». NTU "KhPI" Bulletin : Power and heat engineering processes and equipment, no 4 (30 décembre 2021) : 29–34. http://dx.doi.org/10.20998/2078-774x.2021.04.04.
Texte intégralRésumé :
Due to the importance of the problems of implementing energy-saving technologies in modern conditions, one of the promising areas is the use of gas turbines for combined heat and power generation. One of the areas of effective development and technical re-equipment is the widespread use of highly economical combined steam and gas plants and gas turbines. The operation of the gas turbine unit “Aquarius” SE NPCG “Zorya-Mashproekt” with the injection of steam into the combustion chamber, which operates on the advanced cycle A-STIG and has in its circuit equipment for water regeneration, condensed from a vapor-gas mixture is considered. For condensation of steam from the vapor-gas mixture, a contact condenser-gas cooler is used, which is a mixing heat exchanger of complex design. The efficiency of heat transfer is determined by the design of the nozzle, namely, the developed heat transfer surface, small hydraulic supports, high heat transfer coefficients. An important aspect is the overall dimensions, which must be within certain limits. In the work it is offered to execute a design of the condenser in the form of a packed column. Different types of nozzles are considered to choose the best option. As a result of thermal design calculation of the contact capacitor, it is proposed to use Rashiga rings (15152) as a nozzle, which provide the lowest height of the nozzle at the required diameter of the device.
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Крюков, Алексей, et Aleksei Kriukov. « Three dimensional gas-dynamic calculation of nozzle block of small flow-rate centripetal turbine ». Vestnik of Astrakhan State Technical University. Series : Marine engineering and technologies 2019, no 4 (15 novembre 2019) : 89–95. http://dx.doi.org/10.24143/2073-1574-2019-4-89-95.
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The article describes the low-consumption turbines as reliable, productive, small-sized actuating mechanisms in various units and machines. Experience in production and use
of low-cost turbine stages contributes to improving the efficiency along with simplifying and re-ducing the cost of manufacturing of the blades and the stage in general. Improving the efficiency
of low-consumption turbines requires solving the problem of aerodynamic improvement of the flow part and the calculated determination of the optimal geometry and operating modes of the impeller flow. One of the innovative ways to improve the design efficiency of low-consumption turbines is the automation of the development process using modern modeling systems based on the developed software systems. Due to the small size of the design, the design calculations of turbine stages of this type have been made in a one-dimensional formulation with the involvement of various analogies with classical stages. Using three-dimensional gas dynamic calculations based on the ANSYS CFX platform will significantly improve the quality of design of flow parts of low-flow turbines. Implementation of three-dimensional gas-dynamic calculation of the nozzle unit using the software package ANSYS CFX low-consumption turbine stage can solve this problem. The geometric model is built using AutoCAD software, the grid is selected, the boundary conditions are set. The values of the experimental coefficients of the nozzle velocity, neck velocity and the tangential component of velocity at the nozzle outlet have been compared with the coefficients obtained when using the software package. There have been built the velocity fields and made conclusions about feasibility of using the ANSYS CFX software package to determine the main parameters of a three-dimensional flow of the turbine stage.
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Kostyukov, A. V., et M. E. Plykin. « Effect of power racks in the inter-turbine nozzle of the two-shaft gas turbine engine to uneven flow at the entrance to the power-turbine ». Izvestiya MGTU MAMI 5, no 1 (10 janvier 2011) : 36–40. http://dx.doi.org/10.17816/2074-0530-69831.
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The article examines the results of mathematical modeling of gas flow in the stage of power turbine of the two-shaft regenerative gas turbine engine. The authors showed a significant effect of power racks in inter-turbine nozzle of the two-shaft gas turbine engine on the effectiveness of power turbine.
20
Godin, T., S. Harvey et P. Stouffs. « High-Temperature Reactive Flow of Combustion Gases in an Expansion Turbine ». Journal of Turbomachinery 119, no 3 (1 juillet 1997) : 554–61. http://dx.doi.org/10.1115/1.2841157.
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The analysis of the chemical behavior of the working fluid in gas turbines is usually restricted to the combustion chamber sections. However, the current trend toward higher Turbine Inlet Temperatures (TIT), in order to achieve improved thermal efficiency, will invalidate the assumption of frozen composition of the gases in the first stages of the expansion process. It will become necessary to consider the recombination reactions of the dissociated species, resulting in heat release during expansion. In order to quantify the influence of this reactivity on the performance of high TIT gas turbines, a one-dimensional model of the reactive flow has been developed. Preliminary results were reported in a previous paper. The authors concluded that, in the case of expansion of combustion gases in a subsonic static uncurved distributor nozzle, the residual reactivity must be taken into account above a temperature threshold of around 2000 K. The present study extends these results by investigating the reactive flow in a complete multistage turbine set, including a transonic first-stage nozzle. A key result of this study is that heat release during the expansion process itself will be considerable in future high-temperature gas turbines, and this will have significant implications for turbine design techniques. Furthermore, we show that, at the turbine exit, the fractions of NO and CO are very different from the values computed at the combustor outlet. In particular, NO production in the early part of the expansion process is very high. Finally, the effects of temperature fluctuations at the turbine inlet are considered. We show that residual chemical reactivity affects the expansion characteristics in gas turbines with TITs comparable to those attained by modern high-performance machines.
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Kumakura, H., T. Matsumura, E. Tsuruta et A. Watanabe. « A Control System for a High-Quality Generating Set Equipped With a Two-Shaft Gas Turbine ». Journal of Engineering for Gas Turbines and Power 113, no 2 (1 avril 1991) : 290–95. http://dx.doi.org/10.1115/1.2906561.
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A control system has been developed for a high-quality generating set (150-kW) equipped with a two-shaft gas turbine featuring a variable power turbine nozzle. Because this generating set satisfies stringent frequency stability requirements, it can be employed as the direct electric power source for computer centers without using constant-voltage, constant-frequency power supply systems. Conventional generating sets of this kind have normally been powered by single-shaft gas turbines, which have a larger output shaft inertia than the two-shaft version. Good frequency characteristics have also been realized with the two-shaft gas turbine, which provides superior quick start ability and lower fuel consumption under partial loads.
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Симашов, Р. Р., et С. В. Чехранов. « Determination of gas-dynamic characteristics of nozzle diaphragms with supersonic rectangular nozzles in the modeling of variable duties of low-consumption turbines ». MORSKIE INTELLEKTUAL`NYE TEHNOLOGII)</msg> ;, no 1(55) (3 mars 2022) : 107–11. http://dx.doi.org/10.37220/mit.2022.55.1.013.
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Проектирование новой многорежимной малорасходной турбины предполагает постановку и решение задачи многорежимной оптимизации. Степень достоверности решения в большой степени определяется совпадением истинных и принятых в расчете потерь кинетической энергии в элементах проточной части турбины. На основе экспериментальных данных различных авторов установлена четкая граница по числу Маха на выходе из сопел, позволяющая выделить область, где эффективность сверхзвуковых МРТ с прямоугольными соплами выше, чем с осесимметричными. В работе приводятся обобщающие зависимости коэффициентов потерь кинетической энергии сопловых аппаратов со сверхзвуковыми прямоугольными соплами в широком диапазоне изменения определяющих геометрических и режимных параметров. Получены эмпирические формулы, учитывающие влияние геометрического угла выхода потока из сопел, геометрической степени расширения сопла, относительной высоты, относительной толщины выходных кромок сопел и числа Маха на коэффициент потерь кинетической энергии соплового аппарата. Переменные режимы работы сопла учитываются двухпараметрической зависимостью относительного коэффициента профильных потерь в функции от числа Маха и геометрической степени расширения сопла и зависимостью поправочного коэффициента концевых потерь в функции от числа Маха. Полученные в работе эмпирические зависимости позволяют использовать их при моделировании переменных режимов и многорежимной оптимизации малорасходных турбин. The design of a new multi-mode low-consumption turbine involves the formulation and solution of the multi-mode optimization problem. The degree of reliability of the solution is largely determined by the coincidence of the true and calculated losses of motional energy in the elements of the flow path of the turbine. Based on the experimental data of various authors, a clear boundary has been established in terms of the Mach number at the nozzle outlet, which makes it possible to single out the region where the efficiency of supersonic low-consumption turbines with rectangular nozzles is higher than with axisymmetric ones. The paper presents generalizing dependences of the motional energy loss ratios of nozzle diaphragms with rectangular supersonic nozzles in a wide range of variation of the governing geometrical and operating parameters. Empirical formulas are obtained that take into account the influence of the geometric angle of the flow from the nozzles, the geometric degree of expansion of the nozzle, the relative height, the relative thickness of the outlet edges of the nozzles and the Mach number on the motional energy loss ratio of the nozzle diaphragm. Variable duties of the nozzle operation are taken into account by the two-parameter dependence of the relative coefficient of profile losses as a function of the Mach number and the geometric degree of expansion of the nozzle and the dependence of the correction coefficient of end losses as a function of the Mach number. The empirical dependencies obtained in this work make it possible to use them in modeling variable duties and multi-mode optimization of low-consumption turbines.
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Darantiah Ruing, Gregory Rama, Antonius Ibi Weking et Lie Jasa. « ANALISIS DAN PERBANDINGAN SEGITIGA KERJA : TURBIN SUDU SETENGAH LINGKARAN, SUDU SEGITIGA DAN SUDU SIRIP UNTUK MENGHASILKAN RPM YANG TERTINGGI ». Jurnal SPEKTRUM 6, no 2 (1 juin 2019) : 78. http://dx.doi.org/10.24843/spektrum.2019.v06.i02.p12.
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At present the power plant has a high dependence on energy sources such as diesel, natural gas and coal, while its energy source in nature is increasingly scarce, this situation encourages the development of renewable energy, one of which is in micro hydro power plants. This study aims to determine the effect of the width of the work triangle on the highest rpm produced. the fall of water on the pinwheel is set from the position angle of the nozzle 00, 150, 300, 450, 600, 750 and from the angle of the nozzle 00, 50, 100, 150, 200, 250, 300, 350 and 400 on the semicircular blade turbine, triangle blade turbine , and fin blade turbines. Semicircular turbine blade, working triangle area produces greater rpm at position of angle nozzle 00 and angle of nozzle 250 with area of work triangle 360,36 cm2, where the position produces 216 rpm at windmill rotation and 1626 rpm at generator rotation. When the nozzle position angle 150 and the nozzle angle 200 with the working triangle area 264.27 cm2, produce 221 rpm at the pinwheel rotation and 1711 rpm at the generator rotation. while at the nozzle position angle of 300 and the angle of the nozzle 100 the area of the triangle works 134.37 cm2 and produces 173 rpm at the spinning wheel and 1307 rpm at the generator rotation. on the triangle blade turbine and fin blade, the working triangle area does not affect the rpm produced.
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Fershalov, Andrey Yu, Mikhail Yu Fershalov, Yuriy Ya Fershalov, Timofey V. Sazonov et Damir I. Ibragimov. « Research Data of Turbine Nozzles of 5-9 Degree Outlet Angles ». Applied Mechanics and Materials 770 (juin 2015) : 547–50. http://dx.doi.org/10.4028/www.scientific.net/amm.770.547.
Texte intégralRésumé :
The article presents experimental data of microturbines nozzle boxes research. It describes mathematical models of nozzle outlet gas angle. Research results are analyzed and recommendations on design of nozzle boxes with small constructive outlet gas angle are given.
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Roy Yap, Mun, et Ting Wang. « Simulation of Producer Gas Fired Power Plants with Inlet Fog Cooling and Steam Injection ». Journal of Engineering for Gas Turbines and Power 129, no 3 (9 décembre 2006) : 637–47. http://dx.doi.org/10.1115/1.2718571.
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Biomass can be converted to energy via direct combustion or thermochemical conversion to liquid or gas fuels. This study focuses on burning producer gases derived from gasifying biomass wastes to produce power. Since the producer gases are usually of low calorific values (LCV), power plant performance under various operating conditions has not yet been proven. In this study, system performance calculations are conducted for 5MWe power plants. The power plants considered include simple gas turbine systems, steam turbine systems, combined cycle systems, and steam injection gas turbine systems using the producer gas with low calorific values at approximately 30% and 15% of the natural gas heating value (on a mass basis). The LCV fuels are shown to impose high compressor back pressure and produce increased power output due to increased fuel flow. Turbine nozzle throat area is adjusted to accommodate additional fuel flows to allow the compressor to operate within safety margin. The best performance occurs when the designed pressure ratio is maintained by widening nozzle openings, even though the turbine inlet pressure is reduced under this adjustment. Power augmentations under four different ambient conditions are calculated by employing gas turbine inlet fog cooling. Comparison between inlet fog cooling and steam injection using the same amount of water mass flow indicates that steam injection is less effective than inlet fog cooling in augmenting power output. Maximizing steam injection, at the expense of supplying the steam to the steam turbine, significantly reduces both the efficiency and the output power of the combined cycle. This study indicates that the performance of gas turbine and combined cycle systems fueled by the LCV fuels could be very different from the familiar behavior of natural gas fired systems. Care must be taken if on-shelf gas turbines are modified to burn LCV fuels.
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Tenango-Pirin, Oscar, Elva Reynoso-Jardón, Juan Carlos García, Yahir Mariaca, Yuri Sara Hernández, Raúl Ñeco et Omar Dávalos. « Effect of Thermal Barrier Coating on the Thermal Stress of Gas Microturbine Blades and Nozzles ». Strojniški vestnik – Journal of Mechanical Engineering 66, no 10 (15 octobre 2020) : 581–90. http://dx.doi.org/10.5545/sv-jme.2020.6883.
Texte intégralRésumé :
Thermal barrier coatings play a key role in the operational life of microturbines because they reduce thermal stress in the turbine components. In this work, numerical computations were carried out to assess new materials developed to be used as a thermal barrier coating for gas turbine blades. The performance of the microturbine components protection is also evaluated. The new materials were 8YSZ, Mg2SiO4, Y3Ce7Ta2O23.5, and Yb3Ce7Ta2O23.5. For testing the materials, a 3D gas microturbine model is developed, in which the fluid-structure interaction is solved using CFD and FEM. Temperature fields and stress magnitudes are calculated on the nozzle and blade, and then these are compared with a case in which no thermal barrier is used. Based on these results, the non-uniform temperature distributions are used to compute the stress levels in nozzles and blades. Higher temperature gradients are observed on the nozzle; the maximum temperature magnitudes are observed in the blades. However, it is found that Mg2SiO4 and Y3Ce7Ta2O23.5 provided better thermal insulation for the turbine components compared with the other evaluated materials. Mg2SiO4 and Y3Ce7Ta2O23.5 presented the best performance regarding stress and thermal insulation for the microturbine components. Keywords: thermal barrier coating, gas microturbine, turbine blade, thermal stress
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Gorelov, Yu G., V. V. Ananyev et D. A. Zolotuhina. « 3D investigation of heat exchange and hydrodynamics of high pressure turbine nozzle block platforms with different cooling schemes ». VESTNIK of Samara University. Aerospace and Mechanical Engineering 21, no 2 (7 juillet 2022) : 16–27. http://dx.doi.org/10.18287/2541-7533-2022-21-2-16-27.
Texte intégralRésumé :
Turbine nozzle blocks were tested and, as a result, problems of nozzle block lower platform alligatoring were detected. In the course of the research possible variants of cooling high pressure turbine nozzle block vane platforms were investigated. According to the results of 3D ANSYS CFX calculation the cooling efficiency of high pressure turbine vane platforms with film cooling and convective-film cooling were compared. Research was carried out to eliminate the alligatoring defect of the lower vane platform with convective cooling. Necessary changes in the design were made due to which the cooling air from the secondary combustion chamber area was redistributed over the surface of the turbine nozzle block lower platform. To force the gas turbine engine to the inlet gas temperature to 1800К and more, and to increase the cooling air mass flow from the secondary combustion chamber area over the platforms using convective cooling methods not requiring developed ribbing and impingement cooling, areas of the platforms, as well as zones demanding insignificant intensity of cooling are shown.
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Motamed, Mohammad Ali, et Lars O. Nord. « Assessment of Organic Rankine Cycle Part-Load Performance as Gas Turbine Bottoming Cycle with Variable Area Nozzle Turbine Technology ». Energies 14, no 23 (26 novembre 2021) : 7916. http://dx.doi.org/10.3390/en14237916.
Texte intégralRésumé :
Power cycles on offshore oil and gas installations are expected to operate more at varied load conditions, especially when rapid growth in renewable energies puts them in a load-following operation. Part-load efficiency enhancement is advantageous since heat to power cycles suffer poor efficiency at part loads. The overall purpose of this article is to improve part-load efficiency in offshore combined cycles. Here, the organic Rankine bottoming cycle with a control strategy based on variable geometry turbine technology is studied to boost part-load efficiency. The Variable Area Nozzle turbine is selected to control cycle mass flow rate and pressure ratio independently. The design and performance of the proposed working strategy are assessed by an in-house developed tool. With the suggested solution, the part-load organic Rankine cycle efficiency is kept close to design value outperforming the other control strategies with sliding pressure, partial admission turbine, and throttling valve control operation. The combined cycle efficiency showed a clear improvement compared to the other strategies, resulting in 2.5 kilotons of annual carbon dioxide emission reduction per gas turbine unit. Compactness, autonomous operation, and acceptable technology readiness level for variable area nozzle turbines facilitate their application in offshore oil and gas installations.
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Chaker, Mustapha A., Cyrus B. Meher-Homji et Thomas Mee. « Inlet Fogging of Gas Turbine Engines : Experimental and Analytical Investigations on Impaction Pin Fog Nozzle Behavior ». Journal of Engineering for Gas Turbines and Power 128, no 4 (18 septembre 2006) : 826–39. http://dx.doi.org/10.1115/1.1808429.
Texte intégralRésumé :
The inlet fogging of gas turbine engines for power augmentation has seen increasing application over the past decade. This paper provides the results of extensive experimental and theoretical studies conducted on impaction pin fog nozzles. It covers the important area of the fog plume pattern of impaction pin nozzles and examines fog-plume uniformity. The subject of sprinkle (large droplet formation) from the nozzles is also examined in detail and is shown to be nonsignificant. The effect, on evaporation rate, of ambient climatic conditions and the location of the fog nozzle with respect to the gas turbine inlet duct has been analytically and experimentally analyzed. An analytical model is used to study the evaporation dynamics of fog droplets injected in the inlet ducts. The model is validated experimentally in a wind tunnel.
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Seaver, D. W., et A. M. Beltran. « Nickel-Base Alloy GTD-222, a New Gas Turbine Nozzle Alloy ». Journal of Engineering for Gas Turbines and Power 115, no 1 (1 janvier 1993) : 155–59. http://dx.doi.org/10.1115/1.2906670.
Texte intégralRésumé :
This paper summarizes the key properties of GTD-222 (Wood and Haydon, 1989), a new cast nickel-base nozzle alloy developed by GE for use in land-based gas turbines. GTD-222 is being introduced as a replacement for FSX-414 in second and third-stage nozzles of certain machines. Presented in this paper are comparisons of the tensile, creep-rupture, and fatigue properties of GTD-222 versus FSX-414. In addition, the results of a long-term thermal stability study, high-temperature oxidation, and hot corrosion evaluation as well as weldability results will be discussed.
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Shirpay, M. R., et H. Kazempour-Liacy. « Failure Analysis of a Repaired Gas Turbine Nozzle ». Journal of Failure Analysis and Prevention 13, no 3 (21 février 2013) : 243–48. http://dx.doi.org/10.1007/s11668-013-9667-4.
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Kazempour-Liacy, H., S. Abouali et M. Akbari-Garakani. « Failure analysis of a repaired gas turbine nozzle ». Engineering Failure Analysis 18, no 1 (janvier 2011) : 510–16. http://dx.doi.org/10.1016/j.engfailanal.2010.09.036.
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Tihonchik, S. S., et N. I. Puchko. « Low-pressure nozzle with aerodynamic fuel atomization ». Proceedings of the National Academy of Sciences of Belarus, Physical-Technical Series 65, no 3 (21 octobre 2020) : 357–64. http://dx.doi.org/10.29235/1561-8358-2020-65-3-357-364.
Texte intégralRésumé :
A research was carried out with the construction of a model of a low-pressure nozzle with aerodynamic fuel atomization, which shows the advantages of nozzles of this type. In order to reduce the time at the stage of development and calculations, modern computer design systems were used. The research was carried out in the Flow Simulation module of the SolidWorks software package, which allows you to calculate and build a model of the internal flow around the nozzle using already known parameters. These parameters were set through the program conditions panel: fuel consumption per second; air flow rate at the inlet to the nozzle; static pressure in the combustion chamber. The calculations performed by the module made it possible to evaluate the manufacturability of the design, as well as the internal processes of mixing fuel with air. To determine the quality of fine dispersion of the fuel atomization, a model of the velocity field was calculated over the entire section of the nozzle, from which it can be seen that the maximum flow rate of the fuel is achieved in the outlet channels of the fuel atomizer of the nozzle. The results obtained indicate the operation of the low-pressure principle while maintaining high-quality fuel atomization. The use of low-pressure nozzle with aerodynamic fuel atomization is possible in modern gas turbine engines of civil aircraft, as well as in gas turbine.
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Makarov, Vladimir, Mihail Pesin et Aleksandr Norin. « FEATURES OF USING MULTIAXIS CNC GRINDING MACHINES TO IMPROVE MACHINING PERFORMANCE, QUALITY AND ACCURACYOF PARTS AND ASSEMBLIES OF AVIATION GAS TURBINE ENGINES ». Transport engineering 2023, no 2 (12 février 2023) : 19–26. http://dx.doi.org/10.30987/2782-5957-2023-2-19-26.
Texte intégralRésumé :
The paper is aimed at improving the productivity, quality and accuracy of manufacturing gas turbine engine parts and assemblies for the modern growing passenger aviation transport based on the use of technical capabilities of modern multiaxis CNC grinding machining centers. The paper shows the results of successful application of a five-axis CNC grinding machining center MFP-050.65.65 made by Magerle (Switzerland), which allows reducing by five times the number of operations, universal machines, special devices and cutting tools by increasing the number of machined surfaces for one set of nozzle blades of an aviation gas turbine engine. Simultaneously with a significant increase in the productivity of machining various multidirectional surfaces of the nozzle blades due to the use of new highly porous grinding wheels and rational modes of deep grinding, a higher burn-free quality of the ground surfaces is ensured and an important task is solved to increase the accuracy of the flow sections of the turbine nozzle apparatus with the combined use of CNC system and special software for correcting errors of part casting surfaces during their installation, turning and deep grinding of the base surfaces. The developed new technology of nozzle blades machining was introduced for the first time in the Russian Federation at the Aviadvigatel enterprise for manufacturing nozzle blades of modern newly produced gas turbine engines.
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Fawzy, Hamza, Qun Zheng, Naseem Ahmad et Yuting Jiang. « Optimization of A Swirl with Impingement Compound Cooling Unit for A Gas Turbine Blade Leading Edge ». Energies 13, no 1 (2 janvier 2020) : 210. http://dx.doi.org/10.3390/en13010210.
Texte intégralRésumé :
In this article, a compound unit of swirl and impingement cooling techniques is designed to study the performance of flow and heat transfer using multi-conical nozzles in a leading-edge of a gas turbine blade. Reynolds Averaged Navier-Stokes equations and the Shear Stress Transport model are numerically solved under different nozzle Reynolds numbers and temperature ratios. Results indicated that the compound cooling unit could achieve a 99.7% increase in heat transfer enhancement by increasing the nozzle Reynolds number from 10,000 to 25,000 at a constant temperature ratio. Also, there is an 11% increase in the overall Nusselt number when the temperature ratio increases from 0.65 to 0.95 at identical nozzle Reynolds number. At 10,000 and 15,000 of nozzle Reynolds numbers, the compound cooling unit achieves 47.9% and 39.8% increases and 63.5% and 66.3% increases in the overall Nusselt number comparing with the available experimental swirl and impingement models, respectively. A correlation for the overall Nusselt number is derived as a function of nozzle Reynolds number and temperature ratio to optimize the results. The current study concluded that the extremely high zones and uniform distribution of heat transfer are perfectly achieved with regard to the characteristics of heat transfer of the compound cooling unit.
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Filinov, Evgeny, Andrey Tkachenko, Hewa Hussein Omar et Viktor Rybakov. « Increase the Efficiency of a Gas Turbine Unit for Gas Turbine Locomotives by Means of Steam Injection into the Flow Section ». MATEC Web of Conferences 220 (2018) : 03010. http://dx.doi.org/10.1051/matecconf/201822003010.
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In the modern world of railways, electrification is given great importance. Currently, more than 50% of all freight traffic carried out by electric traction. However, today, about half of the railways are not electrified, so it is necessary to use thermal engines to drive the locomotive. One of the possible variant is use gas turbine unit. The power of the gas turbine unit is given to the electric generator, and the electric motors drive the locomotive. In the present paper, as a power plant of a gas turbine locomotive, considered gas turbine unit with a twin -shaft gas generator of two schemes: 1- with steam supply to the inlet of the high-pressure turbine (into the combustion chamber) and 2- with steam supply to inlet of the free turbine. By CAE system of ASTRA, Collaboration operation lines calculated for different variants of steam injection. When the steam injected into the inlet of a free turbine and a high-pressure turbine. in the case of steam supply to the input of the free turbine and the high-pressure turbine there is a significant shift in Collaboration operation lines, which can lead to a decrease in the gas-dynamical stability of the compressors, and efficiency. To maintain the position of Collaboration operation lines, was applied the correction of the throughput capacity of free turbine nozzle vanes (by 15%). In the case of steam supply to the inlet of a free turbine, to ensure gas-dynamic stability of the compressors, a change in the throughput capacity of its nozzle vanes is required.
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Richards, G. A., R. S. Gemmen et M. J. Yip. « A Test Device for Premixed Gas Turbine Combustion Oscillations ». Journal of Engineering for Gas Turbines and Power 119, no 4 (1 octobre 1997) : 776–82. http://dx.doi.org/10.1115/1.2817054.
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We report the design and operation of a test device suitable for studying combustion oscillations produced by commercial-scale gas turbine fuel nozzles. Unlike conventional test stands, this test combustor uses a Helmholtz acoustic geometry to replicate the acoustic response that would otherwise be observed only during complete engine testing. We suggest that successful simulation of engine oscillations requires that the flame geometry and resonant frequency of the test device should match the complete engine environment. Instrumentation for measuring both pressure and heat release variation is described. Preliminary tests suggest the importance of characterizing the oscillating behavior in terms of a nozzle reference velocity and inlet air temperature. Initial tests also demonstrate that the stabilizing effect of a pilot flame depends on the operating conditions.
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Feng, Yuan, Xuesong Li, Xiaodong Ren, Chunwei Gu, Xuan Lv, Shanshan Li et Ziye Wang. « Experimental and Numerical Investigation of the Non-Reacting Flow in a High-Fidelity Heavy-Duty Gas Turbine DLN Combustor ». Energies 15, no 24 (16 décembre 2022) : 9551. http://dx.doi.org/10.3390/en15249551.
Texte intégralRésumé :
A dry, low-NOx (DLN) combustor for a heavy-duty gas turbine using lean premixed technology was studied. A high-fidelity test model was built for the experimental study using particle image velocimetry (PIV). The non-reacting flow in the DLN combustion chamber was investigated experimentally and numerically. The numerical results are in good agreement with the experimental data. The results show that recirculation zones were formed downstream of each swirl nozzle and that the flow pattern in each section was self-similar under different working conditions. For two adjacent swirl nozzles with opposite swirling directions, the entrainment phenomenon was present between their two flows. The two flows gradually mixed with each other and obtained a higher speed. If the two adjacent swirl nozzles had the same swirling direction, then the mixing of the two flows out of the nozzles was not present, resulting in two separate downstream recirculation zones. The interaction of swirling flows out of different nozzles can enhance the turbulent fluctuation inside the combustion chamber. Based on the analysis of the recirculation zones and turbulent kinetic energy (TKE) distribution downstream of each nozzle, it can be found that nozzle coupling results in stronger recirculation and turbulent mixing downstream counterclockwise surrounding nozzles.
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Hu, Bo, Yulong Yao, Minfeng Wang, Chuan Wang et Yanming Liu. « Flow and Performance of the Disk Cavity of a Marine Gas Turbine at Varying Nozzle Pressure and Low Rotation Speeds : A Numerical Investigation ». Machines 11, no 1 (5 janvier 2023) : 68. http://dx.doi.org/10.3390/machines11010068.
Texte intégralRésumé :
In marine gas turbines, variations in rotational speed occur all the time. To ensure adequate cooling effects on the turbine blades, the valves need to be adjusted to change the pressure upstream of the pre-swirl nozzle. Changing such pressure will have significant effects on the local or overall parameters, such as core swirl ratio, temperature, flow rate coefficient, moment coefficient, axial thrust coefficient, etc. In this paper, we studied the flow characteristics within the pre-swirl system of a marine gas turbine at low rotational speed by varying the pressure at the pre-swirl nozzle. The corresponding global Reynolds number ranged from Re = 2.3793 × 105 to 9.5172 × 105. The flow in the rotor-stator cavities was analyzed to find the effects of nozzle pressure on the radial velocity, core swirl ratio, and pressure. According to the simulation results, we introduced a new leakage flow term into the formulary in the references to calculate the values of K between the inner seal and the pre-swirl nozzle. The matching characteristics between the pre-swirl nozzle and the inclined receiving hole was predicted. Performance of the pre-swirl system was also analyzed, such as the pressure drop, through-flow capacity, and cooling effects. After that, the moment coefficient and the axial thrust coefficient were predicted. This study provides some reference for designers to better design the pre-swirl system.
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Parks, W. P., R. R. Ramey, D. C. Rawlins, J. R. Price et M. Van Roode. « Potential Applications of Structural Ceramic Composites in Gas Turbines ». Journal of Engineering for Gas Turbines and Power 113, no 4 (1 octobre 1991) : 628–34. http://dx.doi.org/10.1115/1.2906287.
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A Babcock and Wilcox-Solar Turbines Team has completed a program to assess the potential for structural ceramic composites in turbines for direct coal-fired or coal gasification environments. A review is made of the existing processes in direct coal firing, pressurized fluid bed combustors, and coal gasification combined cycle systems. Material requirements in these areas were also discussed. The program examined state-of-the-art ceramic composite materials. Utilization of ceramic composites in the turbine rotor blades and nozzle vanes would provide the most benefit. A research program designed to introduce ceramic composite components to these turbines was recommended.
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Кухтин, Юрий Петрович, et Руслан Юрьевич Шакало. « СНИЖЕНИЕ ВИБРОНАПРЯЖЕННОСТИ ПОПАРНО БАНДАЖИРОВАННЫХ РАБОЧИХ ЛОПАТОК ТУРБИНЫ ». Aerospace technic and technology, no 7 (31 août 2020) : 52–58. http://dx.doi.org/10.32620/aktt.2020.7.08.
Texte intégralRésumé :
To reduce the vibration stresses arising in the working blades of turbines during resonant excitations caused by the frequency of passage of the blades of the nozzle apparatus, it is necessary to control the level of aerodynamic exciting forces. One of the ways to reduce dynamic stresses in rotor blades under operating conditions close to resonant, in addition to structural damping, maybe to reduce external exciting forces. To weaken the intensity of the exciting forces, it is possible to use a nozzle apparatus with multi-step gratings, as well as with non-radially mounted blades of the nozzle apparatus.This article presents the results of numerical calculations of exciting aerodynamic forces, as well as the results of experimental measurements of stresses arising in pairwise bandaged working blades with a frequency zCA ⋅ fn, where fn – is the rotor speed, zCA – is the number of nozzle blades. The object of research was the high-pressure turbine stage of a gas turbine engine. Two variants of a turbine stage were investigated: with the initial geometry of the nozzle apparatus having the same geometric neck area in each interscapular channel and with the geometry of the nozzle apparatus obtained by alternating two types of sectors with a reduced and initial throat area.The presented results are obtained on the basis of numerical simulation of a viscous unsteady gas flow in a transonic turbine stage using the SUnFlow home code, which implements a numerical solution of the Reynolds-averaged Navier-Stokes equations. Discontinuity of a torrent running on rotor blades is aggravated with heat drops between an ardent flow core and cold jets from film cooling of a blade and escapes on clock surfaces. Therefore, at simulation have been allowed all blowngs cooling air and drain on junctions of shelves the impeller.As a result of the replacement of the nozzle apparatus with a constant passage area by a nozzle apparatus with a variable area, a decrease in aerodynamic driving force by 12.5 % was obtained. The experimentally measured stresses arising in a pairwise bandaged blade under the action of this force decreased on average by 26 %.
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Mustafa, Alaaeldin H. « Failure Analysis of Heavy Industrial Gas Turbine Engine First Stage Nozzel Guide Vane ». Advanced Materials Research 445 (janvier 2012) : 1047–52. http://dx.doi.org/10.4028/www.scientific.net/amr.445.1047.
Texte intégralRésumé :
Failure analysis investigation was conducted on 70 MW set of 1st stage turbine nozzle guide vanes (NGVs) of heavy industrial gas turbine. The failure was investigated using the light optical microscope (LOM), X-ray diffraction analysis (XRD) and energy dispersive X-ray spectroscopy (EDS) in an environmental scanning electron microscope (ESEM). The results of the analysis indicate that the NGVs which were made of Co base superalloy FSX-414 had been operated above the recommended operating hours under different fuel types in addition to inadequate repair process in previous repair removal. The XRD analysis of the fractured areas sample shows presence ofwhich might indicate the prolonged operation at high temperature. Keywords: cobalt-base; nozzle guide vanes, gas turbine.
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Sun, Tao, Bo Wan, Chang Jiang Sun et Zheng Wei Ma. « Multi-Stage Ejector Design and Numerical Simulation for Marine Gas Turbine ». Advanced Materials Research 1078 (décembre 2014) : 280–85. http://dx.doi.org/10.4028/www.scientific.net/amr.1078.280.
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With the continuous development of infrared-guided weapons, the survival of ship at sea faces increasingly challenges especially high-risk waters. The ship gas turbine exhaust ejector is the core component parts, charged with the task of reducing or even eliminating the infrared radiation signal of ship gas turbine exhaust systems. In the designing of exhaust ejector, structure forms of nozzle have a big influence on its ejector effect. Making a rational design of nozzle, which working in a narrow space, to reduce the exhaust temperature effectively while minimizing the impact of flow of gas turbine body has always been a focus and difficulty. In this article, a multistage ejector is designed by adding a second-stage ejector section based on an independent design of single-stage ejector.
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Fulara, Szymon, Maciej Chmielewski et Marian Gieras. « Variable Geometry in Miniature Gas Turbine for Improved Performance and Reduced Environmental Impact ». Energies 13, no 19 (8 octobre 2020) : 5230. http://dx.doi.org/10.3390/en13195230.
Texte intégralRésumé :
A miniature gas turbine (MGT) is proposed as a promising future energy source. Increasingly stringent requirements related to harmful combustible gas emissions and a trend towards improved energy generation efficiency drive the quest for new MGT technologies. Variable geometry systems are promising due to enhanced heat management and flow control. Variable combustor cooling and dilution holes together with the variable area nozzle (VAN) system allow for the improvement of gas turbine performance and reduction in pollutant emissions. The proposed systems are based on hot-section geometry changes, in which the size of the combustion chamber holes and turbine nozzle angle can be adjusted. Component and module experimental research were performed at the Warsaw University of Technology, on an MGT test stand. A significant decrease in fuel consumption (up to 47% reduction) and harmful nitrogen oxide emission reduction (NO–by 78% and NO2–by 82%) were achieved. These results are related to combustor turbine inlet temperature (TIT) increase up to 1230 K. The tests of the variable geometry systems have also shown an impact on gas turbine power and specific fuel consumption.
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Liu, Aiguo, Ruiyang Fan, Qiaochu Liu, Lei Xi et Wen Zeng. « Numerical and Experimental Study on Combustion Characteristics of Micro-Gas Turbine Biogas Combustor ». Energies 15, no 21 (7 novembre 2022) : 8302. http://dx.doi.org/10.3390/en15218302.
Texte intégralRésumé :
The use of biogas in land-based gas turbines for power generation is a promising approach to reducing greenhouse gases and our dependence on fossil fuels. The focus of this research was to investigate the fuel/air mixing and combustion performance in an DLE (dry low emission) type can combustor designed for a micro-gas turbine. The fuel and air mixing uniformity was studied considering the air flow characteristic and fuel injection performance through the numerical simulation. The influence of the fuel/air mixing characteristics on the combustion characteristics was studied by numerical simulation and experimental tests. The combustion characteristics studied included the temperature field in the combustor, the pattern factor at the combustor outlet, combustion efficiency, and pollutant emission characteristics. The results show the position of the fuel nozzle has little effect on the mixing uniformity due to the limited mixing space for the micro-gas turbine combustor, while there are optimal fuel nozzle diameters to generate the suitable fuel jet momentum for the mixing process. The fuel/air mixing characteristics had an obvious influence on the combustion performance for the studied DLE combustor. The increase in the fuel air mixing uniformity can decrease the NOx emissions and generate a better temperature distribution at the combustor outlet. The increased mixing uniformity may decrease the combustion efficiency and increase the CO emissions of the micro-gas turbine combustor.
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Barringer, M. D., O. T. Richard, J. P. Walter, S. M. Stitzel et K. A. Thole. « Flow Field Simulations of a Gas Turbine Combustor ». Journal of Turbomachinery 124, no 3 (1 juillet 2002) : 508–16. http://dx.doi.org/10.1115/1.1475742.
Texte intégralRésumé :
The flow field exiting the combustor in a gas turbine engine is quite complex considering the presence of large dilution jets and complicated cooling schemes for the combustor liner. For the most part, however, there has been a disconnect between the combustor and turbine when simulating the flow field that enters the nozzle guide vanes. To determine the effects of a representative combustor flow field on the nozzle guide vane, a large-scale wind tunnel section has been developed to simulate the flow conditions of a prototypical combustor. This paper presents experimental results of a combustor simulation with no downstream turbine section as a baseline for comparison to the case with a turbine vane. Results indicate that the dilution jets generate turbulence levels of 15–18% at the exit of the combustor with a length scale that closely matches that of the dilution hole diameter. The total pressure exiting the combustor in the near-wall region neither resembles a turbulent boundary layer nor is it completely uniform putting both of these commonly made assumptions into question.
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Skachkov, S. V., et D. D. Shpakovskiy. « Numerical simulation of gas flow in jet nozzle ». Journal of «Almaz – Antey» Air and Space Defence Corporation, no 3 (30 septembre 2016) : 41–46. http://dx.doi.org/10.38013/2542-0542-2016-3-41-46.
Texte intégralRésumé :
We determined traction and hydraulic characteristics of the jet nozzle of a gas turbine engine, taking into account the geometry of the internal structural elements and flow swirl in the inlet section according to the results of numerical simulation.
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Iyengar, Vishwas, Harold Simmons et David Ransom. « Flash Atomization : A New Concept to Control Combustion Instability in Water-Injected Gas Turbines ». Journal of Combustion 2012 (2012) : 1–10. http://dx.doi.org/10.1155/2012/718202.
Texte intégralRésumé :
The objective of this work is to explore methods to reduce combustor rumble in a water-injected gas turbine. Attempts to use water injection as a means to reduce NOXemissions in gas turbines have been largely unsuccessful because of increased combustion instability levels. This pulsation causes chronic fretting, wear, and fatigue that damages combustor components. Of greater concern is that liberated fragments could cause extensive damage to the turbine section. Combustion instability can be tied to the insufficient atomization of injected water; large water droplets evaporate non-uniformly that lead to energy absorption in chaotic pulses. Added pulsation is amplified by the combustion process and acoustic resonance. Effervescent atomization, where gas bubbles are injected, is beneficial by producing finely atomized droplets; the gas bubbles burst as they exit the nozzles creating additional energy to disperse the liquid. A new concept for effervescent atomization dubbed “flash atomization” is presented where water is heated to just below its boiling point in the supply line so that some of it will flash to steam as it leaves the nozzle. An advantage of flash atomization is that available heat energy can be used rather than mechanical energy to compress injection gas for conventional effervescent atomization.
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Hoffren, J., T. Talonpoika, J. Larjola et T. Siikonen. « Numerical Simulation of Real-Gas Flow in a Supersonic Turbine Nozzle Ring ». Journal of Engineering for Gas Turbines and Power 124, no 2 (26 mars 2002) : 395–403. http://dx.doi.org/10.1115/1.1423320.
Texte intégralRésumé :
In small Rankine cycle power plants, it is advantageous to use organic media as the working fluid. A low-cost single-stage turbine design together with the high molecular weight of the fluid leads to high Mach numbers in the turbine. Turbine efficiency can be improved significantly by using an iterative design procedure based on an accurate CFD simulation of the flow. For this purpose, an existing Navier-Stokes solver is tailored for real gas, because the expansion of an organic fluid cannot be described with ideal gas equations. The proposed simulation method is applied for the calculation of supersonic flow in a turbine stator. The main contribution of the paper is to demonstrate how a typical ideal-gas CFD code can be adapted for real gases in a very general, fast, and robust manner.
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Saith, A., P. F. Norton et V. M. Parthasarathy. « Application of SPSLIFE to Preliminary Design Evaluation and Life Assessment of CSGT Components ». Journal of Engineering for Gas Turbines and Power 117, no 3 (1 juillet 1995) : 424–31. http://dx.doi.org/10.1115/1.2814114.
Texte intégralRésumé :
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.