Series Gas Turbine Research Articles

Система «турбина – генератор» с наблюдателем состояния нагрузки

Objective: To generate a mathematical model of a gas turbine engine state observer for a GT1h series gas turbine locomotive. Methods: Calculations and modeling of processes were performed using software packages for mathematical modeling of complex electromechanical systems with implementation in Matlab, while data processing and graph plotting were performed using Microsoft Excel. Results: It has been shown that the use of the mathematical model of the state observer in the automatic control system allows providing conditions for the formation of an optimal power load trajectory of the Gas Turbine Engine — Traction Generator system when regulating the power, taking into account the limitations associated with the physical processes occurring in the gas turbine engine. Practical importance: The use of the mathematical model of the state observer makes it possible to generate rational gas turbine load trajectories in the entire range of its use.

Numerical analysis of air entrainment and exit temperature of a real scale conical infrared suppression (IRS) device

A numerical analysis has been performed on a real-scale infrared suppression device to estimate the air entrainment and corresponding temperature drop of the exhaust gases flowing through it. The analysis of the IRS device is done for the exhaust of a gas turbine plant installed on a naval warship. The operational data used in the analysis has been taken from LM2500 series gas turbine from GE. The numerical method solves the three dimensional, incompressible Navier-Stokes equations, the mass continuity equation and the two-equation based eddy viscosity model for the turbulent k-epsilon equations along with the energy equation in the flow field. The effect of using different number of nozzles at the gas turbine exit on the air entrainment and the exit plume temperature has been discussed. The results show that the maximum air entrainment and minimum plume temperature can be achieved by using four to six numbers of nozzles. The air entrainment and the exit plume temperature are also affected by the pitch circle diameter of the nozzle placement. The maximum air entrainment and minimum exit temperature is achieved at a pitch circle diameter of 1.6 m. The air entrainment considerably increases with the nozzle-exit Reynolds number (Re). The higher Reynolds number also ensures the minimum plume temperature at the exit of IRS device. Air entrainment gradually reduces with the nozzle protrusion. The highest entrainment is observed when the nozzles are flush with the bottom plane of the IRS device. However, the nozzle protrusion does not affect the exit plume temperature significantly. The funnel overlap height adversely affects the performance of the IRS device i.e. the air entrainment continuously decreases with increasing funnel overlap height. Moreover, increasing funnel overlap also causes the exit plume temperature to rise considerably.

Reduction of fuel consumption of small gas turbines at idling under combined operation with adjustable compressor inlet and turbine outlet guide vanes

AbstractFor the experimental verification of the effect of adjustable compressor inlet guide vanes combined with adjustable turbine outlet guide vanes for reducing the fuel consumption at idling, an 8 kW test gas turbine was designed and built up. The data of the experiments with the test gas turbine was compared with experimental data acquired by the author from another gas turbine. Additionally, experimental data was compared with external data of other heat engines. Using the newly introduced dimensionless Kruschik number, the test gas turbine, two series gas turbines and an internal combustion engine was compared in terms of their required heat supply at idling.

Construction Diagnostics of the Aircraft Parts on the Basis of the Energy Method and the Stress-state Stiffness Criterion

The analysis of the stress-strain state on the basis of equivalent stress and the theories of durability is used for diagnostics of parts at present moment in the typical strength calculations. However a lot of basic aviation parts work at cyclically repeated loadings and they are exposed to loadings and deformation in the field of low and high cycle fatigue. In this case there is necessity of deformation condition calculations or the stress-strain type which significantly influences on the cyclic durability of the parts. For increasing of reliability and cyclic durability of the parts the research purpose is to develop a way and criteria of the analysis and assessment of the stress-strain state for the identification of the most loaded areas of the parts limiting its fatigue. It is offered to consider the stress-strain type on the basis of coefficient of stiffness KS calculated through the main tensions. In this case it is recommended to determine the most subjected to cracking initiating areas of the parts by the largest size of parameter K = KSKU. The research of the finite element analysis of the stress-strain state for the low pressure turbine shaft and high pressure compressor disks of D-30 series gas turbine engine was made according to this parameter. On the basis of this parameter the finite element analysis of the stress-strain state for the low pressure turbine shaft and high pressure compressor disks of the gas-turbine engine of D-30 series is researched in this work.

Research of a heat-resistant intermetallic underlayer for the heat-shielding coating of gas turbine engine turbine blades

The paper presents the results of research of the structure as well as physical and mechanical properties of a heat-resistant intermetallic coating of a Ni-Co-Cr-Al-Y system produced by the method of high-energy plasma powder spraying and used as a substrate in forming a heat-shielding zirconium dioxide coating. A coating is produced with an intermetallic phase composition (b-NiAl+ g-Ni3Al) and spheroidal grain microstructure. The density of the coating is r=8200 kg/m 3, the microhardness is Нm=7,85 GPa and the roughness is 5mkm. According to the results of testing the heat shielding of the wall of a turbine blade made of the ЖС6Ф alloy with the help of a heat-shielding ZrO2 coating with a Ni-Co-CR-Al-Y substrate the metal temperature reduction amounted to 398 K. The coating is intended for the protection of the working surface of various-application gas turbine engine turbine blades against high-temperature gas corrosion in the form of a substrate for the heat-shielding zirconium dioxide coating, and also as an independent heat-shielding coating. The plasma heat-shielding coating for the Ni-Co-CR-Al-Y system has been tested as a substrate for a heat-shielding coating of zirconium dioxide with a view to extending the service life of turbine blades (made of a heat-resistant ЖС6Ф alloy) of the NK series gas turbine engine turbines.

Powering Ahead

This article explores the increasing use of natural gas in different turbine industries and in turn creating an efficient electrical system. All indications are that the aviation market will be good for gas turbine production as airlines and the military replace old equipment and expanding economies such as China and India increase their air travel. Gas turbines now account for some 22% of the electricity produced in the United States and 46% of the electricity generated in the United Kingdom. In spite of this market share, electrical power gas turbines have kept a much lower profile than competing technologies, such as coal-fired thermal plants and nuclear power. Gas turbines are also the primary device behind the modern combined power plant, about the most fuel-efficient technology we have. Mitsubishi Heavy Industries is developing a new J series gas turbine for the combined cycle power plant market that could achieve thermal efficiencies of 61%. The researchers believe that if wind turbines and gas turbines team up, they can create a cleaner, more efficient electrical power system.

Evolution and Future Trend of Large Frame Gas Turbine for Power Generation

Mitsubishi Heavy Industries, Ltd. (MHI) developed a 1100°C class D series gas turbine in the 1980s and constructed the world’s first successful large-scale combined cycle power plant. Since then, MHI has developed the F and G series gas turbines with higher turbine inlet temperature and has delivered these units worldwide accumulating successful commercial operations. These gas turbines are constantly improved, adding to their successful operation. MHI is currently participating in a Japanese National Project to promote the development of component technology for the next generation 1700°C class gas turbine. The thermal efficiency will be improved significantly with this new technology by raising the turbine inlet temperature and the pressure ratio. MHI recently developed a 1600°C class J series gas turbine utilizing some of the technologies developed in the National Project. This paper discusses the history and the evolution of MHI large frame gas turbine for power generation and the activities currently in progress for an environmentally friendly technology in the future.

Availability Analysis of Gas Turbines Used in Power Plants

The availability of a complex system, such as a gas turbine, is strongly associated with its parts reliability and maintenance policy. That policy not only has influence on the parts’ repair time but also on the parts’ reliability affecting the system degradation and availability. This study presents a method for reliability and availability evaluation of gas turbines installed in an electric power station. The method is based on system reliability concepts, such as functional tree development, application of failure mode and effects analysis to identify critical components for improvement of system reliability, and reliability and maintainability evaluation based on a historical failure database. The method also proposes the application of Reliability Centered Maintenance concepts to improve complex system maintenance policies aimed at the reduction of unexpected failure occurrences in critical components. The method is applied to the analysis of two F series gas turbines, each with an output of 150 MW, installed in a 500 MW combined cycle power plant. The reliability and availability of the turbines are simulated based on a five-year failure database. The availability analysis shows different results for each turbine, one presenting 99% and the other 96% availability, indicating differences in their systems installation and operation.

Application of “H Gas Turbine” Design Technology to Increase Thermal Efficiency and Output Capability of the Mitsubishi M701G2 Gas Turbine

Mitsubishi completed design development and verification load testing of a steam-cooled M501H gas turbine at a combined cycle power plant at Takasago, Japan in 2001. Several advanced technologies were specifically developed in addition to the steam-cooled components consisting of the combustor, turbine blades, vanes, and the rotor. Some of the other key technologies consisted of an advanced compressor with a pressure ratio of 25:1, active clearance control, and advanced seal technology. Prior to the M501H, Mitsubishi introduced cooling-steam in “G series” gas turbines in 1997 to cool combustor liners. Recently, some of the advanced design technologies from the M501H gas turbine were applied to the G series gas turbine resulting in significant improvement in output and thermal efficiency. A noteworthy aspect of the technology transfer is that the upgraded G series M701G2 gas turbine has an almost equivalent output and thermal efficiency as H class gas turbines while continuing to rely on conventional air cooling of turbine blades and vanes, and time-proven materials from industrial gas turbine experience. In this paper we describe the key design features of the M701G2 gas turbine that make this possible such as the advanced 21:1 compressor with 14 stages, an advanced premix DLN combustor, etc., as well as shop load test results that were completed in 2002 at Mitsubishi’s in-house facility.

Rolls Royce/Allison 501-K Gas Turbine Antifouling Compressor Coatings Evaluation

The Naval Surface Warfare Center, Carderock Division (NSWCCD) Gas Turbine Emerging Technologies Code 9334 was tasked by NSWCCD Shipboard Energy Office Code 859 to research and evaluate fouling resistant compressor coatings for Rolls Royce Allison 501-K Series gas turbines. The objective of these tests was to investigate the feasibility of reducing the rate of compressor fouling degradation and associated rate of specific fuel consumption (SFC) increase through the application of anti-fouling coatings. Code 9334 conducted a market investigation and selected coatings that best fit the test objective. The coatings selected were Sermalon for compressor stages 1 and 2 and Sermaflow S4000 for the inlet guide vanes and remaining 12 compressor stages. Both coatings are manufactured by Sermatech International, are intended to substantially decrease blade surface roughness, have inert top layers, and contain an anti-corrosive aluminum-ceramic base coat. Sermalon contains a Polytetrafluoroethylene (PTFE) topcoat, a substance similar to Teflon, for added fouling resistance. Tests were conducted at the Philadelphia Land Based Engineering Site (LBES). Testing was first performed on the existing LBES 501-K17 gas turbine, which had an uncoated compressor. The compressor was then replaced by a coated compressor and the test was repeated. The test plan consisted of injecting a known amount of salt solution into the gas turbine inlet while gathering compressor performance degradation and fuel economy data for 0, 500, 1000, and 1250 KW generator load levels. This method facilitated a direct comparison of compressor degradation trends for the coated and uncoated compressors operating with the same turbine section, thereby reducing the number of variables involved. The collected data for turbine inlet, temperature, compressor efficiency, and fuel consumption were plotted as a percentage of the baseline conditions for each compressor. The results of each plot show a decrease in the rates of compressor degradation and SFC increase for the coated compressor compared to the uncoated compressor. Overall test results show that it is feasible to utilize antifouling compressor coatings to reduce the rate of specific fuel consumption increase associated with compressor performance degradation.

On some perspectives for increasing the efficiency of combined cycle power plants

The paper proposes an analysis of some possibilities to increase the combined cycle plant efficiency to values higher than the 60% without resorting to a new gas turbine technology. Optimization of heat recovery steam generator (HRSG) with the use of parallel sections and of limit subcritical conditions (up to 220 bar) is the key elements to obtain this result. The HRSG optimization is sufficient to obtain combined cycle plant efficiencies of the order of 60% while, joining HRSG optimization with the use of gas turbine reheat (postcombustion) and gas to gas recuperation can lead the efficiency of the whole plant to the limit value of 65%. Results are proposed with reference to a turbine inlet temperature of 1500 K, corresponding to those of usual commercial D–F series gas turbine.

Technical Features and Long-term Operating Experience of Mitsubishi Advanced M 501 G Gas Turbine

The combined cycle power plant is recognized as one of the best thermal power plants for its high efficiency and cleanliness. Under these circumstances. Mitsubishi Heavy Industries, Ltd.(MHI) developed large, heavy-duty 1, 200C class M 701 D (for 50Hz utility) gas turbine and 1, 400C class M 501 F (for 60Hz)/M 701 F (for 50Hz) gas turbines. Their high efficiency and reliability for combined cycle applications have been proven in field operations. Based on the fact that the combined cycle efficiency is highly dependent on the gas firing temperature, MHI has newly developed the 1, 500C class M 501 G (for 60Hz)/M 701 G (for 50Hz), which is called “G” series, gas turbines.Development of the “G” series gas turbine was started in early 1990' s and the design was based on the following concepts, which give excellent performance and high reliability to the “G” series.Firstly, proven features from the “F” series are kept. Secondly, the most advanced technologies in aerodynamic design, heat transfer design and new materials for the “G” series are introduced. Thirdly, our conventional design criteria in industrial gas turbines are applied. Fourthly, NOx and the metal temperature remains at the same level as the “F” series by applying steam-cooled combustors even though the turbine inlet temperature is increased. Finally, special measurements and verification tests are carried out before commercial operation to secure their high reliability.The trial operation of the M 501 G was conducted in 1997 in the combined cycle verification plant in MHI Takasago. Japan. It was successful and the commercial operation was started in June 1997. Since then, the detail inspections were conducted and the condition of each component was quite sound. Therefore, the availability. defined as the actual power supply hours over demanded power supply hours excluding scheduled shutdown such as periodical inspection, during the commercial operation was 98.6%.The trial operation of the M 701 G was conducted in October 1998 in the domestic utility company. After completion of plant tests, the commercial operation was started in July 1999. The availability during commercial operation is 100%.This paper describes the technical features and up-to-date operating status of the M 501 G combined cycle power plant in MHI Takasago.

System Evaluation and LBTU Fuel Combustion Studies for IGCC Power Generation

The integration of gas turbines and combined cycle systems with advances in coal gasification and gas stream cleanup systems will result in economically viable IGCC systems. Optimization of IGCC systems for both emission levels and cost of electricity is critical to achieving this goal. A technical issue is the ability to use a wide range of coal and petroleum-based fuel gases in conventional gas turbine combustor hardware. In order to characterize the acceptability of these syngases for gas turbines, combustion studies were conducted with simulated coal gases using full-scale advanced gas turbine (7F) combustor components. It was found that NOx emissions could be correlated as a simple function of stoichiometric flame temperature for a wide range of heating values while CO emissions were shown to depend primarily on the H2 content of the fuel below heating values of 130 Btu/scf (5125 kJ/NM3) and for H2/CO ratios less than unity. The test program further demonstrated the capability of advanced can-annular combustion systems to burn fuels from air-blown gasifiers with fuel lower heating values as low as 90 Btu/scf (3548 kJ/NM3) at 2300°F (1260°C) firing temperature. In support of ongoing economic studies, numerous IGCC system evaluations have been conducted incorporating a majority of the commercial or near-commercial coal gasification systems coupled with “F” series gas turbine combined cycles. Both oxygen and air-blown configurations have been studied, in some cases with high and low-temperature gas cleaning systems. It has been shown that system studies must start with the characteristics and limitations of the gas turbine if output and operating economics are to be optimized throughout the range of ambient operating temperature and load variation.