Effect of Variable Guide Vanes and Natural Gas Hybridization for Accommodating Fluctuations in Solar Input to a Gas Turbine

2011 ◽  
Author(s):  
Kyle Kitzmiller ◽  
Fletcher Miller
Keyword(s):  
Gas Turbine ◽  
Flow Rate ◽  
Gas Turbine Engine ◽  
Solar Thermal ◽  
Guide Vanes ◽  
Operational Strategies ◽  
Turbine Engine ◽  
Variable Nature ◽  
Wide Range ◽  
Solar Powered

In recent years, several prototype solar central receivers have been experimentally demonstrated to produce high temperature and high pressure gas capable of driving a gas turbine engine [1–4]. While these prototype receivers are generally small (< 1 MWth), advancements in this technology will allow for the development of solar powered gas turbine engines at a commercial level (sizes of at least several megawatts electric (MWe)). The current paper analyzes a recuperated solar powered gas turbine engine, and addresses engine considerations, such as material limitations, as well as the variable nature of solar input. In order to compensate for changes in solar input, two operational strategies are identified and analyzed. The first is hybridization, meaning the solar input is supplemented via the combustion of fossil fuels. Hybridization often allows for an increase in net power and efficiency by adding heat during periods of low solar thermal input. An alternative strategy is to make use of variable guide vanes on the compressor of the gas turbine engine, which schedule to change the air flow rate into the system. By altering the mass flow rate of air, and assuming a fixed level of heat addition, the operating temperature of the engine can be controlled to maximize power or efficiency. The paper examines how to combine hybridization with variable guide vane operation to optimize gas turbine performance over a wide range of solar thermal input, from zero to solar-only operation. A large material constraint is posed by the combustor, and to address this concern two alternative strategies — one employing a bypass valve and the other a combustor modified to allow higher temperature inlet air — are presented. Combustor modifications could include new materials and/or increased cooling air. The two strategies (bypass vs. no bypass) are compared on a thermodynamic basis. Finally, a yearly assessment of solar share and thermodynamic performance is presented for a 4.8 MWe gas turbine to identify the overall benefits of the operational strategies.

Effect of Variable Guide Vanes and Natural Gas Hybridization for Accommodating Fluctuations in Solar Input to a Gas Turbine

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Kyle Kitzmiller ◽  
Fletcher Miller
Keyword(s):  
Gas Turbine ◽  
Flow Rate ◽  
Gas Turbine Engine ◽  
Solar Thermal ◽  
Guide Vanes ◽  
Operational Strategies ◽  
Turbine Engine ◽  
Variable Nature ◽  
Thermodynamic Performance ◽  
Solar Powered

In recent years, several prototype solar central receivers have been experimentally demonstrated to produce high temperature and high pressure gas capable of driving a gas turbine engine. While these prototype receivers are generally small (<1 MWth), advancements in this technology will allow for the development of solar powered gas turbine engines at a commercial level (sizes of at least several megawatts electric (MWe)). The current paper analyzes a recuperated solar powered gas turbine engine, and addresses engine considerations, such as material limitations, as well as the variable nature of solar input. In order to compensate for changes in solar input, two operational strategies are identified and analyzed. The first is hybridization, meaning the solar input is supplemented via the combustion of fossil fuels. Hybridization often allows for an increase in net power and efficiency by adding heat during periods of low solar thermal input. An alternative strategy is to make use of variable guide vanes on the compressor of the gas turbine engine, which schedule to change the air flow rate into the system. By altering the mass flow rate of air, and assuming a fixed level of heat addition, the operating temperature of the engine can be controlled to maximize power or efficiency. The paper examines how to combine hybridization with variable guide vane operation to optimize gas turbine performance over a wide range of solar thermal input, from zero solar input to solar-only operation. A large material constraint is posed by the combustor, and to address this concern two alternative strategies—one employing a bypass valve and the other a combustor modified to allow higher temperature inlet air—are presented. Combustor modifications could include new materials and/or increased cooling air. The two strategies (bypass versus no bypass) are compared on a thermodynamic basis. It is found that it is possible to operate the gas turbine across the entire range without a significant drop in performance in either design through judicious adjustment of the vanes, though both approaches yield different results for certain ranges of solar input. Finally, a yearly assessment of solar share and thermodynamic performance is presented for a 4.3 MWe gas turbine to identify the overall benefits of the operational strategies. The annualized thermodynamic performance is not appreciably different for the two strategies, so that other factors such as mechanical design, operational issues, economics, etc. must be used to decide the optimal approach.

Validation and Comparison of Strip Seal Designs for Gas Turbine Engine Nozzle Guide Vanes

2008 ◽  
Author(s):  
Arash Farahani ◽  
Peter Childs
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Gas Turbine Engine ◽  
Experimental Comparison ◽  
Cfd Modelling ◽  
Guide Vanes ◽  
Turbine Engine ◽  
Seal Design ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes

Strip seals are commonly used to prevent or limit leakage flows between nozzle guide vanes (NGV) and other gas turbine engine components that are assembled from individual segments. Leakage flow across, for example, a nozzle guide vane platform, leads to increased demands on the gas turbine engine internal flow system and a rise in specific fuel consumption (SFC). Careful attention to the flow characteristics of strip seals is therefore necessary. The very tight tolerances associated with strip seals provides a particular challenge to their characterisation. This paper reports the validation of CFD modelling for the case of a strip seal under very carefully controlled conditions. In addition, experimental comparison of three types of strip seal design, straight, arcuate, and cloth, is presented. These seals are typical of those used by competing manufacturers of gas turbine engines. The results show that the straight seal provides the best flow sealing performance for the controlled configuration tested, although each design has its specific merits for a particular application.

scholarly journals METHOD OF FORMULATING INPUT PARAMETERS OF NEURAL NETWORK FOR DIAGNOSING GAS-TURBINE ENGINES

Aviation ◽  
2013 ◽  
Vol 17 (2) ◽  
pp. 52-56 ◽  
Author(s):  
Mykola Kulyk ◽  
Sergiy Dmitriev ◽  
Oleksandr Yakushenko ◽  
Oleksandr Popov
Keyword(s):  
Neural Network ◽  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Training Data ◽  
Turbine Engines ◽  
Data Sets ◽  
Gas Turbine Engines ◽  
Turbine Engine ◽  
Wide Range ◽  
And Training

A method of obtaining test and training data sets has been developed. These sets are intended for training a static neural network to recognise individual and double defects in the air-gas path units of a gas-turbine engine. These data are obtained by using operational process parameters of the air-gas path of a bypass turbofan engine. The method allows sets that can project some changes in the technical conditions of a gas-turbine engine to be received, taking into account errors that occur in the measurement of the gas-dynamic parameters of the air-gas path. The operation of the engine in a wide range of modes should also be taken into account.

Exploration of Compact Combustors for Reheat Cycle Aero Engine Applications

2006 ◽  
Author(s):  
J. Zelina ◽  
D. T. Shouse ◽  
J. S. Stutrud ◽  
G. J. Sturgess ◽  
W. M. Roquemore
Keyword(s):  
Gas Turbine ◽  
Temperature Rise ◽  
Gas Turbines ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Combustion System ◽  
Turbine Engine ◽  
Lean Blowout ◽  
Power Extraction ◽  
Wide Range

An aero gas turbine engine has been proposed that uses a near-constant-temperature (NCT) cycle and an Inter-Turbine Burner (ITB) to provide large amounts of power extraction from the low-pressure turbine. This level of energy is achieved with a modest temperature rise across the ITB. The additional energy can be used to power a large geared fan for an ultra-high bypass ratio transport aircraft, or to drive an alternator for large amounts of electrical power extraction. Conventional gas turbines engines cannot drive ultra-large diameter fans without causing excessively high turbine temperatures, and cannot meet high power extraction demands without a loss of engine thrust. Reducing the size of the combustion system is key to make use of a NCT gas turbine cycle. Ultra-compact combustor (UCC) concepts are being explored experimentally. These systems use high swirl in a circumferential cavity about the engine centerline to enhance reaction rates via high cavity g-loading on the order of 3000 g’s. Any increase in reaction rate can be exploited to reduce combustor volume. The UCC design integrates compressor and turbine features which will enable a shorter and potentially less complex gas turbine engine. This paper will present experimental data of the Ultra-Compact Combustor (UCC) performance in vitiated flow. Vitiation levels were varied from 12–20% oxygen levels to simulate exhaust from the high pressure turbine (HPT). Experimental results from the ITB at atmospheric pressure indicate that the combustion system operates at 97–99% combustion efficiency over a wide range of operating conditions burning JP-8 +100 fuel. Flame lengths were extremely short, at about 50% of those seen in conventional systems. A wide range of operation is possible with lean blowout fuel-air ratio limits at 25–50% below the value of current systems. These results are significant because the ITB only requires a small (300°F) temperature rise for optimal power extraction, leading to operation of the ITB at near-lean-blowout limits of conventional combustor designs. This data lays the foundation for the design space required for future engine designs.

Experimental Investigation of an Inert Gas Generator for Fire Suppressing

2001 ◽  
Author(s):  
SooYong Kim ◽  
A. Slitenko
Keyword(s):  
Experimental Investigation ◽  
Gas Turbine ◽  
Mass Flow Rate ◽  
Oxygen Content ◽  
Flow Rate ◽  
Gas Turbine Engine ◽  
Inert Gas ◽  
Gas Generator ◽  
Turbine Engine ◽  
Exit Nozzle

Present study deals with experimental and theoretical performance analysis of an inert gas generator(IGG) which can be used as an effective mean to suppress the fire. The system consists of a gas turbine engine and afterburning system with injection of water, exit nozzle to produce the inert gas. It is generally known that the degree of oxygen content in the product of combustion depends on both inlet and outlet temperature of a combustor. Less the oxygen content in the combustion product higher will be the effectiveness of fire suppression. Injection of water brings additional advantages of suffocating and cooling effects which are both indespensable factors for fire suppressing. The special test rig was manufactured and experimental investigation of IGG system has been carried out. The automatic control system ensured stable operation of gas turbine engine and afterburner, water injection, fuel control and others. During the investigation the main parameters of gas turbine engine and auxiliarly systems were measured: gas temperature and pressure at gas turbine and afterburner exit, fuel flow rate, water mass flow rate, inlet air temperature, water temperature in the cooling chamber, mass flow rate, temperature and velocity of exhaust gas-steam mixture in the exit nozzle, oxygen content in the exit jet. The experimental investigation shows that developed IGG system can work very well for indoor fires but need some modifications in application to outdoor fire suppressing.

scholarly journals THE METHOD OF CONTROLLING THE SUPPLY OF CRYOGENIC FUEL IN A GAS TURBINE ENGINE

2021 ◽  
Vol 6 (3) ◽  
pp. 33-40
Author(s):  
V. A. Shishkov
Keyword(s):  
Phase Transition ◽  
Heat Exchanger ◽  
Liquid Phase ◽  
Power Plant ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Flow Rate ◽  
Internal Combustion Engines ◽  
Gas Turbine Engine ◽  
Turbine Engine

increasing the efficiency of the power plant. A method of controlling the supply of cryogenic fuel to a gas turbine engine is to pump its liquid phase, followed by its separation into two parts and controlling the flow rate of each part. Heated the first part of the cryogenic fuel to a gaseous state in the heat exchanger, mixing it with the second part and feeding the resulting mixture of cryogenic fuel into the combustion chamber. The first part of the cryogenic fuel flow rate is passed through the heat exchanger Gta = Gsm [Ср_sm (Тfp + T) il] / [ig il], where Gsm is the consumption of cryogenic fuel at the outlet of the mixer, Ср_sm is the isobaric heat capacity of cryogenic fuel at the outlet from the mixer, Тfp is the temperature of the phase transition of cryogenic fuel from liquid to gas at a pressure in the mixer, T is the temperature of the gas mixture of cryogenic fuel at the outlet of the mixer above the temperature of the phase transition, il is the enthalpy of the first part of the liquid phase of cryogenic fuel at the input ode to the heat exchanger and the second part of the liquid phase of the cryogenic fuel, which is fed to the second entrance to the mixer, ig is the enthalpy of the gaseous phase of the cryogenic fuel at the outlet of the heat exchanger, at which it is fed to the first entrance to the mixer. Moreover, ig Ср_sm (Тfp + T) il and Gsm = Gta + Gl, where Gl is the flow rate of the second part of the liquid phase of the cryogenic fuel, which is fed to the second input to the mixer. When the pressure of the cryogenic fuel in the mixer is below the critical value Pkr, the temperature Тfp of the phase transition from liquid to gas of the cryogenic fuel is taken equal to the temperature Тnas on the saturation line of the cryogenic fuel at the corresponding pressure in the mixer. The excess of the temperature of the cryogenic fuel mixture over the phase transition temperature after mixing the gas and liquid phases at the mixer outlet sets T = 60 ... 170 for cryogenic methane and T = 150 ... 260 for cryogenic hydrogen. Due to the gasification of a part of the cryogenic fuel consumption in the heat exchanger and subsequent mixing of this part with the second liquid part of the cryogenic fuel in the mixer, the freezing of the outer surface of the heat exchanger in all operating modes of the power plant is reduced. Due to the reduction of external freezing of the channels of the heat exchanger, the heat transfer efficiency is increased in it. By reducing the dimensions of the heat exchanger, the hydraulic losses in the gas-dynamic path of the power plant are reduced, which, in turn, increases its efficiency. By lowering the temperature of the gas phase of the cryogenic fuel at the inlet to the combustion chamber, the temperature of the exhaust gases at its outlet is reduced, which, in turn, increased the reliability of the gas turbine of the power plant. The method of operation of the cryogenic fuel supply system is intended for ground-based power plants and vehicles. The work is intended for scientists and designers in the field of cryogenic fuels for internal combustion engines.

scholarly journals Theory of gas turbine engine optimal gas generator

2019 ◽  
Vol 18 (2) ◽  
pp. 52-61
Author(s):  
A. V. Grigoriev ◽  
A. A. Kosmatov ◽  
О. A. Rudakov ◽  
A. V. Solovieva
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Flow ◽  
Turbine Blades ◽  
Target Function ◽  
Gas Turbine Engine ◽  
Gas Generator ◽  
Joint Operation ◽  
Turbine Engine ◽  
Wide Range

The article substantiates the necessity of designing an optimal gas generator of a gas turbine engine. The generator is to provide coordinated joint operation of its units: compressor, combustion chamber and compressor turbine with the purpose of reducing the period of development of new products, improving their fuel efficiency, providing operability of the blades of a high-temperature cooled compressor turbine and meeting all operational requirements related to the operation of the optimal combustion chamber including a wide range of stable combustion modes, high-altitude start at subzero air and fuel temperature conditions and prevention of the atmosphere pollution by toxic emissions. Methods of optimizing the parameters of coordinated joint operation of gas generator units are developed. These parameters include superficial flow velocities in the boundary interface cross sections between the compressor and the combustion chamber, as well as between the combustion chamber and the compressor turbine. The effective efficiency of the engine thermodynamic cycle is the optimization target function. The required depth of the turbine blades cooling is a functional constraint evaluated with account for calculations of irregularity and instability of the gas temperature field and the actual flow turbulence intensity at the blades’ inlet. We carried out theoretical analysis of the influence of various factors on the gas flow that causes changes in the flow total pressure in the channels of the gas generator gas dynamic model, i.e. changes in the efficiencies of its units. It is shown that the long period (about five years) of the engine final development time, is due to the necessity to perform expensive full-scale tests of prototypes, in particular, it is connected with an incoordinate assignment in designing the values of the flow superficial velocities in the boundary sections between the gas generator units. Designing of an optimal gas generator is only possible on the basis of an integral mathematical model of an optimal combustion chamber.

Description and Performance of a 7000-Shp Marine Gas Turbine Engine

1978 ◽  
Author(s):  
J. R. Strother
Keyword(s):  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Modern Technology ◽  
General Motors ◽  
Turbine Engine ◽  
Wide Range ◽  
Endurance Testing ◽  
Industrial Use ◽  
And Performance ◽  
Mechanical Arrangement

Detroit Diesel Allison (DDA) Division of General Motors Corporation, has developed a 7000-shp class gas turbine engine for industrial use. The engine uses proven modern technology which results in low-fuel consumption over a wide range of power and a compact installation envelope. Approximately 5000 hr of performance and endurance testing have been accumulated to date. Testing is continuing at DDA and the first-field installation was completed in September 1977 in a stationary air compressor application. It is anticipated that 10,000 hr of engine test experience will be gained prior to production unit availability in 1978. This paper discusses the mechanical arrangement, performance, control system, installation and maintenance features, and status of the Model 570 engine.

scholarly journals AUTOMATION CONTROL SYSTEM OF TECHNICAL CONDITION OF GAS TURBINE ENGINE COMPRESSOR

2019 ◽  
pp. 121-128
Author(s):  
Микола Сергійович Кулик ◽  
Володимир Вікторович Козлов ◽  
Лариса Георгіївна Волянська
Keyword(s):  
Gas Turbine ◽  
Flow Rate ◽  
Static Pressure ◽  
Air Flow ◽  
Gas Turbine Engine ◽  
Technical Condition ◽  
Operating Conditions ◽  
Air Flow Rate ◽  
Turbine Engine ◽  
Flow Duct

The article is devoted to one of the approaches to the construction of an automated system for solving the problems of diagnostics and monitoring of the flow duct of aircraft gas turbine engines and gas turbine plants. Timely detection of faults and subsequent monitoring of their development in operation are possible thanks to automated systems for assessing the technical condition of engines. This is particularly relevant in operating conditions as the knowledge of the technical condition of the engine is necessary in any engine maintenance system allows  to choose the content and timing of maintenance, repair of the flow duct of gas turbine engines and gas turbine plants, as well as commissioning. The engineering technique, which can be applied at performance of maintenance and at stages of tests and debugging of aircraft engines, is considered. The automated system implements a method of measuring the air flow through the compressor and a technique for assessing the technical condition of the compressor by the relative change in air flow. To determine the air flow rate through the gas turbine engine, it is sufficient to measure only static pressure values in the flow part. The static pressure receivers are not located in the flow part and do not obscure it, and thus do not affect the compressor gas dynamic stability margin. The inspection area is selected for measuring in the flow duct of the air intake. Static pressure in the maximum and minimum cross sections of the chosen area is measured; the maximum cross-section area of the flow duct, the total temperature of the air flow is measured outside the air intake.  To determine the air flow rate, the functional dependence of the air flow rate on the static pressure is used. The algorithm for monitoring and diagnosing the operating condition of the engine is based on a comparison of the actual values of air flow rate with the air flow rate determined during the control tests or when using a mathematical model adapted for this gas turbine engine. The positive effect of the using of the proposed automated control system of technical condition is that the air flow rate measured under operating conditions will significantly increase the objectivity of the control of the operation and technical condition of the gas turbine engine.

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