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.

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.

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.

Initial Operation and Analysis of a Cogeneration Laboratory

2002 ◽  
Author(s):  
Andrew Banta
Keyword(s):  
Performance Analysis ◽  
Gas Turbine ◽  
Waste Heat ◽  
Gas Turbine Engine ◽  
California State University ◽  
State University ◽  
Absorption Chiller ◽  
Waste Heat Boiler ◽  
Turbine Engine ◽  
Thermodynamic Performance

California State University, Sacramento, has constructed and put into service a stand alone cogeneration laboratory. The major components are a 75 kW gas turbine and generator, a waste heat boiler, and a 10 ton absorption chiller. Initial testing has been completed with efforts concentrating on the gas turbine engine and the absorption chiller. A two part thermodynamic performance analysis procedure has been developed to analyze the cogeneration plant. A first law energy balance around the gas turbine determines the heat into the engine. A Brayton cycle analysis of the gas turbine engine is then compared with the measured performance. While this engine is quite small, this method of analysis gives very consistent results and can be applied to engines of all sizes. Careful attention to details is required to obtain agreement between the calculated and measured outputs; typically they are within 10 to 15 percent. In the second part of the performance analysis experimental operation of the absorption chiller has been compared to that specified by the manufacturer and a theoretical cycle analysis. While the operation is within a few percent of that specified by the manufacturer, there are some interesting differences when it is compared to a theoretical analysis.

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.

Performance Simulation and Analysis of a Gas Turbine Engine Using Drop-In Bio-Fuels

2018 ◽  
Author(s):  
J. S. Rubie ◽  
Y. G. Li ◽  
A. J. B. Jackson
Keyword(s):  
Gas Turbine ◽  
Simulation Method ◽  
Gas Turbine Engine ◽  
Simulation Software ◽  
Performance Model ◽  
Performance Simulation ◽  
Turbine Engine ◽  
Thermodynamic Performance ◽  
Model Engine ◽  
Blended Fuels

There is an increasing dependence on conventional fuels for aviation. In order for a country’s air force to sustain a steady and a secure supply of fuel for aircraft with foresight into the future, alternate sources of fuels must be considered. This paper describes a thermodynamic performance simulation method and analysis of a model military aero gas turbine engine operating in several off-design modes while employing various types of blended fuels between Jet A and alternate bio-fuels, including Synthetic Paraffinic Kerosene (SPK) from Algae (Bio-Algae), Jatropha (JSPK) and Camelina (CSPK). These fuels are already approved by American Society for Testing and Materials (AS™) for blending with 50% Jet A fuel. A thermodynamic performance model for the model engine similar to GE F404-400 turbofan engine has been set up using Pythia, a Cranfield University created performance simulation software implemented with multiple fuel capabilities. The simulated performance and a comparative study shows that the performance of the model engine using blended fuels between Jet A and a bio-fuel were found to be equal or better than that using pure conventional fuel Jet A. The key hot section temperatures, pressures and the fuel consumption of the model engine were found to be slightly lower with the blended fuels than that using Jet A.

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.

scholarly journals Estimation of cooling flow rate for conceptual design stage of a gas turbine engine

2021 ◽  
Vol 1891 (1) ◽  
pp. 012011
Author(s):  
E P Filinov ◽  
V S Kuz’michev ◽  
Yu A Tkachenko ◽  
Ya A Ostapyuk ◽  
H H Omar ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Conceptual Design ◽  
Flow Rate ◽  
Gas Turbine Engine ◽  
Design Stage ◽  
Turbine Engine ◽  
Cooling Flow ◽  
Conceptual Design Stage
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