Operating Results With Gas Turbines of Large Output

1964 ◽  
Vol 86 (1) ◽  
pp. 29-49 ◽  
Author(s):  
H. Pfenninger
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Ash Content ◽  
Liquid Fuels ◽  
Gas Turbine Blades ◽  
Gaseous Fuels ◽  
Fuel Oils ◽  
Dust Composition

Operational figures of some Brown Boveri gas-turbine installations classed according to the fuel burned: oil, blast furnace gas, natural gas. Corrosion and contamination of gas-turbine blades, laboratory and pilot tests, general considerations, fuel oils obtainable, their ash content and composition, and their suitability for use in gas turbines. Effect of the ash content and ash composition of liquid fuels, and of the dust content and dust composition of gaseous fuels on the life of the blading material. Drop in output and efficiency with time. Reduction of the rate of contamination of the blades by additives in the fuel. Experience with natural gas-fired gas turbines. Plant maintenance costs.

Development and Integration of the Dual Fuel Combustion System for the MGT Gas Turbine Family

2021 ◽  
Author(s):  
Bernhard Ćosić ◽  
Frank Reiss ◽  
Marc Blümer ◽  
Christian Frekers ◽  
Franklin Genin ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Distribution System ◽  
Gas Turbines ◽  
Liquid Fuel ◽  
Fuel Injection ◽  
Liquid Fuels ◽  
Dual Fuel ◽  
Gaseous Fuels ◽  
Supply And Distribution ◽  
Industrial Gas Turbines

Abstract Industrial gas turbines like the MGT6000 are often operated as power supply or as mechanical drives. In these applications, liquid fuels like 'Diesel Fuel No.2' can be used either as main fuel or as backup fuel if natural gas is not reliably available. The MAN Gas Turbines (MGT) operate with the Advanced Can Combustion (ACC) system, which is capable of ultra-low NOx emissions for gaseous fuels. This system has been further developed to provide dry dual fuel capability. In the present paper, we describe the design and detailed experimental validation process of the liquid fuel injection, and its integration into the gas turbine package. A central lance with an integrated two-stage nozzle is employed as a liquid pilot stage, enabling ignition and start-up of the engine on liquid fuel only. The pilot stage is continuously operated, whereas the bulk of the liquid fuel is injected through the premixed combustor stage. The premixed stage comprises a set of four decentralized nozzles based on fluidic oscillator atomizers, wherein atomization of the liquid fuel is achieved through self-induced oscillations. We present results illustrating the spray, hydrodynamic, and emission performance of the injectors. Extensive testing of the burner at atmospheric and full load high-pressure conditions has been performed, before verification within full engine tests. We show the design of the fuel supply and distribution system. Finally, we discuss the integration of the dual fuel system into the standard gas turbine package of the MGT6000.

Acoustic Thermography Testing of Industrial Gas Turbine Blades in the Service Stage

2008 ◽  
Author(s):  
Mattias Broddega˚rd ◽  
Christian Homma
Keyword(s):  
Gas Turbine ◽  
Test Object ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Medium Size ◽  
Testing Time ◽  
Testing Technique ◽  
Ir Camera ◽  
Gas Turbine Blades ◽  
Industrial Gas Turbine

Gas turbine blades are operating under very demanding conditions. In modern industrial gas turbines, the rotating blades and the guide vanes of the first stages are hollow to allow internal cooling. This means that there is a possibility of having crack initiation on the internal surface of the components. Due to the complex casting geometry, this type of defects is very difficult to detect with conventional nondestructive testing techniques such as ultrasonic and radiographic testing. Siemens has developed a new non-destructive testing technique based on acoustic thermography, SIEMAT. The test object is energized by an ultrasonic excitation device. Due to the vibrations, a very slight heating will develop at cracks in the test object. The local increase of temperature is captured by a highly sensitive IR camera. The SIEMAT technique is capable of detecting both surface-breaking and internal cracks, including cracks under coatings. The testing time is very short, and the IR sequences are recorded for subsequent analysis. A major advantage for service applications is that the technique is mostly sensitive to closed defects such as cracks, since open defects where no contact between the faces is present, for example pores and scratch marks, will not cause any heat generation. Siemens is currently implementing the SIEMAT technique for assessment of service-exposed turbine blades from medium size gas turbines, which are due for reconditioning. By being able to verify that no internal cracks are present, the reliability of the reconditioned blades will be increased. This paper describes the SIEMAT testing technique, and the results obtained when applied on service-exposed industrial gas turbine blades.

CFD Analysis of Turbec T100 Combustor at Part Load by Varying Fuels

2015 ◽  
Author(s):  
Raffaela Calabria ◽  
Fabio Chiariello ◽  
Patrizio Massoli ◽  
Fabrizio Reale
Keyword(s):  
Natural Gas ◽  
Gas Turbines ◽  
Combustion Process ◽  
Calorific Value ◽  
Operating Conditions ◽  
Liquid Fuels ◽  
Cfd Analysis ◽  
Part Load ◽  
Gaseous Fuels ◽  
Wide Range

In recent years an increasing interest is focused on the study of micro gas turbines (MGT) behavior at part load by varying fuel, in order to determine their versatility. The interest in using MGT is related to the possibility of feeding with a wide range of fuels and to realize efficient cogenerative cycles by recovering heat from exhaust gases at higher temperatures. In this context, the studies on micro gas turbines are focused on the analysis of the machine versatility and flexibility, when operating conditions and fuels are significantly varied. In line of principle, in case of gaseous fuels with similar Wobbe Index no modifications to the combustion chamber should be required. The adoption of fuels whose properties differ greatly from those of design can require relevant modifications of the combustor, besides the proper adaptation of the feeding system. Thus, at low loads or low calorific value fuels, the combustor becomes a critical component of the entire MGT, as regards stability and emissions of the combustion process. Focus of the paper is a 3D CFD analysis of the combustor behavior of a Turbec T100P fueled at different loads and fuels. Differences between combustors designed for natural gas and liquid fuels are also highlighted. In case of natural gas, inlet combustor temperature and pressure were taken from experimental data; in case of different fuels, such data were inferred by using a thermodynamic model which takes into account rotating components behavior through operating maps of compressor and turbine. Specific aim of the work is to underline potentialities and critical issues of the combustor under study in case of adoption of fuels far from the design one and to suggest possible solutions.

scholarly journals Prediction of Auto-Ignition Temperatures and Delays for Gas Turbine Applications

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Roda Bounaceur ◽  
Pierre-Alexandre Glaude ◽  
Baptiste Sirjean ◽  
René Fournet ◽  
Pierre Montagne ◽  
...  
Keyword(s):  
High Temperature ◽  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Equivalence Ratio ◽  
Process Conditions ◽  
Piping System ◽  
Gaseous Fuels ◽  
Auto Ignition ◽  
Wide Range

Gas turbines burn a large variety of gaseous fuels under elevated pressure and temperature conditions. During transient operations, variable gas/air mixtures are involved in the gas piping system. In order to predict the risk of auto-ignition events and ensure a safe operation of gas turbines, it is of the essence to know the lowest temperature at which spontaneous ignition of fuels may happen. Experimental auto-ignition data of hydrocarbon–air mixtures at elevated pressures are scarce and often not applicable in specific industrial conditions. Auto-ignition temperature (AIT) data correspond to temperature ranges in which fuels display an incipient reactivity, with timescales amounting in seconds or even in minutes instead of milliseconds in flames. In these conditions, the critical reactions are most often different from the ones governing the reactivity in a flame or in high temperature ignition. Some of the critical paths for AIT are similar to those encountered in slow oxidation. Therefore, the main available kinetic models that have been developed for fast combustion are unfortunately unable to represent properly these low temperature processes. A numerical approach addressing the influence of process conditions on the minimum AIT of different fuel/air mixtures has been developed. Several chemical models available in the literature have been tested, in order to identify the most robust ones. Based on previous works of our group, a model has been developed, which offers a fair reconciliation between experimental and calculated AIT data through a wide range of fuel compositions. This model has been validated against experimental auto-ignition delay times corresponding to high temperature in order to ensure its relevance not only for AIT aspects but also for the reactivity of gaseous fuels over the wide range of gas turbine operation conditions. In addition, the AITs of methane, of pure light alkanes, and of various blends representative of several natural gas and process-derived fuels were extensively covered. In particular, among alternative gas turbine fuels, hydrogen-rich gases are called to play an increasing part in the future so that their ignition characteristics have been addressed with particular care. Natural gas enriched with hydrogen, and different syngas fuels have been studied. AIT values have been evaluated in function of the equivalence ratio and pressure. All the results obtained have been fitted by means of a practical mathematical expression. The overall study leads to a simple correlation of AIT versus equivalence ratio/pressure.

scholarly journals Investigation of the Relationship between Degradation of the Coating of Gas Turbine Blades and Its Surface Color

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7843
Author(s):  
Mariusz Bogdan ◽  
Józef Błachnio ◽  
Artur Kułaszka ◽  
Dariusz Zasada
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Protective Coatings ◽  
Turbine Blades ◽  
Operating Time ◽  
Surface Color ◽  
Metallographic Examination ◽  
Gas Turbine Blades ◽  
Study Results ◽  
The Relationship

This article presents issues concerning the relationship between the degradation of the coating of gas turbine blades and changes in the color of its surface. Conclusions were preceded by the determination of parameters characterizing changes in the technical condition of protective coatings made based on a metallographic examination that defined the morphological modifications of the microstructure of the coating, chemical composition of oxides, and roughness parameters. It has been shown that an increased operating time causes parameters that characterize the condition of the blades to deteriorate significantly. Results of material tests were compared with those of blade surface color analyses performed using a videoscope. Image data were represented in two color models, i.e., RGB and L*a*b* with significant differences being observed between parameters in both representations. The study results demonstrated a relationship between the coating degradation degree and changes in the color of the blade’s surface. Among others, this approach may be used as a tool to assess the condition of turbine blades as well as entire gas turbines.

scholarly journals Computer Predictions of Erosion Damage in Gas Turbines

1987 ◽  
Author(s):  
A. F. Abdel Azim El-Sayed ◽  
A. Brown
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Iterative Procedure ◽  
Pressure Coefficient ◽  
Turbine Blades ◽  
Engine Performance ◽  
Erosion Damage ◽  
Gas Turbine Blades ◽  
Coefficient Distribution ◽  
Blade Section

In this article an iterative procedure is presented for estimating erosion in axial gas turbine blades. The procedure is applied to a two stage turbine and the erosion is estimated for a 12,000 hour engine running time. The effect of the erosion on engine performance is estimated through changes in pressure coefficient distribution around a blade section.

Wide Gap Braze Repair of Gas Turbine Blades and Vanes—A Review

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Xiao Huang ◽  
Warren Miglietti
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Life Cycle Cost ◽  
Turbine Blades ◽  
Advanced Materials ◽  
Gas Turbine Blades ◽  
Rare Elements ◽  
Compositional Choices ◽  
Useful Life ◽  
Wide Gap

Gas turbine blades and vanes in modern gas turbines are subjected to an extremely hostile environment. As such, sophisticated airfoil designs and advanced materials have been developed to meet stringent demands and at the same time, ensure increased performance. Despite the evolution of long-life airfoils, damage still occurs during service thus limiting the useful life of these components. Effective repair of after-service components provides life-cycle cost reduction of engines, and as well, contributes to the preservation of rare elements heavily used in modern superalloys. Among these methods developed in the last four decades for the refurbishment and joining of superalloy components, wide gap brazing (WGB) technology has been increasingly used in the field owing to its ability to repair difficult to weld alloys, to build up substantially damaged areas in one operation, and to provide unlimited compositional choices to enhance the properties of the repaired region. In this paper, the historical development of wide gap repair technology currently used in industry is reviewed. The microstructures and mechanical properties of different WGB joints are compared and discussed. Subsequently, different WGB processes employed at major OEMs are summarized. To conclude this review, future developments in WGB repair of newer generations of superalloys are explored.

scholarly journals Combustion and Oxidation Kinetics of Alternative Gas Turbines Fuels

2014 ◽  
Author(s):  
Pierre-Alexandre Glaude ◽  
Baptiste Sirjean ◽  
René Fournet ◽  
Roda Bounaceur ◽  
Matthieu Vierling ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Ignition Temperature ◽  
Alternative Fuels ◽  
Flame Temperature ◽  
Liquid Fuels ◽  
Heavy Oils ◽  
Process Gas ◽  
Auto Ignition

Heavy duty gas turbines are very flexible combustion tools that accommodate a wide variety of gaseous and liquid fuels ranging from natural gas to heavy oils, including syngas, LPG, petrochemical streams (propene, butane…), hydrogen-rich refinery by-products; naphtha; ethanol, biodiesel, aromatic gasoline and gasoil, etc. The contemporaneous quest for an increasing panel of primary energies leads manufacturers and operators to explore an ever larger segment of unconventional power generation fuels. In this moving context, there is a need to fully characterize the combustion features of these novel fuels in the specific pressure, temperature and equivalence ratio conditions of gas turbine combustors using e.g. methane as reference molecule and to cover the safety aspects of their utilization. A numerical investigation of the combustion of a representative cluster of alternative fuels has been performed in the gas phase, namely two natural gas fuels of different compositions, including some ethane, a process gas with a high content of butene, oxygenated compounds including methanol, ethanol, and DME (dimethyl ether). Sub-mechanisms have specifically been developed to include the reactions of C4 species. Major combustion parameters, such as auto-ignition temperature (AIT), ignition delay times (AID), laminar burning velocities of premixed flames, adiabatic flame temperatures, and CO and NOx emissions have then been investigated. Finally, the data have been compared with those calculated for methane flames. These simulations show that the behaviors of alternative fuels markedly differ from that of conventional ones. Especially, DME and the process gases appear to be highly reactive with significant impacts on the auto-ignition temperature and flame speed data, which justifies burner design studies within premixed combustion schemes and proper safety considerations. The behaviors of alcohols (especially methanol) display some commonalities with those of conventional fuels. In contrast, DME and process gas fuels develop substantially different flame temperature and NOx generation rates than methane. Resorting to lean premix conditions is likely to achieve lower NOx emission performances. This review of gas turbine fuels shows for instance that the use of methanol as a gas turbine fuel is possible with very limited combustor modifications.

scholarly journals Transpiration Air Protected Turbine Blades: An Effective Concept to Achieve High Temperature and Erosion Resistance for Gas Turbines Operating in an Aggressive Environment

1978 ◽  
Author(s):  
R. Raj ◽  
S. L. Moskowitz
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Erosion Resistance ◽  
Turbine Blades ◽  
Future Generation ◽  
Combined Cycle ◽  
Gaseous Fuels ◽  
Cooled Blade

The future generation is looking forward to the use of gas turbine inlet temperatures as high as 3000 F (1650 C) with attendant thermal efficiencies of from 40 to 50 percent in combined cycle electric power plants. In addition to the use of high temperature for improved efficiency, the national needs, due to scarcity of oil and natural gas, will heavily stress the use of coal as a fuel. The particulate from combustion of coal derived liquid and gaseous fuels, even after employing hot gas cleanup systems, may damage conventional turbine blades and thus reduce turbine life. This paper is intended to show how a transpiration-cooled blade can cope with both of the foregoing problems simultaneously. The fundamental aspects of the transpiration-cooled blade technology will also be explained. Experimental results using this design concept indicate that significant erosion resistance is feasible for gas turbine blading in the near future.

Nox emission control in gas turbines for combined cycle gas turbine plant

1997 ◽  
Vol 211 (1) ◽  
pp. 43-52 ◽  
Author(s):  
M J Moore
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Catalytic Reduction ◽  
Water Injection ◽  
Emission Control ◽  
Combined Cycle ◽  
Liquid Fuels ◽  
Gas Combustion ◽  
Natural Gas Combustion

The increase, in recent years, in the size and efficiency of gas turbines burning natural gas in combined cycle has occurred against a background of tightening environmental legislation on the emission of nitrogen oxides. The higher turbine entry temperatures required for efficiency improvement tend to increase NOx production. First-generation emission control systems involved water injection and catalytic reduction and were relatively expensive to operate. Dry low-NOx combustion systems have therefore been developed but demand more primary air for combustion. This gives added incentive to the reduction of air requirements for cooling the combustor and turbine blading. This paper reviews the various approaches adopted by the main gas turbine manufacturers which are achieving very low levels of NOx emission from natural gas combustion. Further developments, however, are necessary for liquid fuels.

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