scholarly journals Gas Turbine Cogeneration Groups Flexibility to Classical and Alternative Gaseous Fuels Combustion

Author(s):  
Ene Barbu ◽  
Romulus Petcu ◽  
Valeriu Vilag ◽  
Valentin Silivestru ◽  
Tudor Prisecaru ◽  
...  
Keyword(s):  
Author(s):  
Bernhard Ćosić ◽  
Frank Reiss ◽  
Marc Blümer ◽  
Christian Frekers ◽  
Franklin Genin ◽  
...  

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.


Author(s):  
Roda Bounaceur ◽  
Pierre-Alexandre Glaude ◽  
Baptiste Sirjean ◽  
René Fournet ◽  
Pierre Montagne ◽  
...  

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.


Author(s):  
W. S. Y. Hung ◽  
J. G. Meier

This paper describes the successful development and application of industrial gas turbines using alternate gaseous fuels. These fuels include liquid petroleum gas, medium-Btu fuels derived from biodegradation of organic matters found in sanitary landfills and liquid sewage, and ultra-low Btu fuels from oilfield fireflood operations. The analyses, mathematical modelling and rig verification performed in the development are discussed. The effects of burning these alternate fuels on the gas turbine and its combustion system are compared to those of using standard natural gas fuel. Gas turbine development required to use other alternative gaseous fuels is also assessed.


Author(s):  
P. A. Glaude ◽  
O. Mahier ◽  
V. Warth ◽  
R. Fournet ◽  
M. Moliere ◽  
...  

Throughout the history of combustion engines, the Heavy Duty Gas Turbine stands out as the most fuel-flexible prime mover in the field. This gas turbine (GT) is suited for a rich portfolio of gaseous fuels that include: natural gas, liquefied petroleum gas, coal and biomass-derived syngases, and a great variety of process gases with diverse compositions (hydrogen, carbon monoxide, olefins, etc.). Process gas fuels provide a promising array of alternative fuel opportunities in the major sectors of the industry such as the Coal, Oil & Gas, Steel, Chemical and Petrochemical branches. In an increasingly uncertain fuel environment, this significant match between gas turbine capabilities and the energy schemes of industrial plants can lead to further business opportunities.


1986 ◽  
Vol 108 (1) ◽  
pp. 182-190 ◽  
Author(s):  
J. G. Meier ◽  
W. S. Y. Hung ◽  
V. M. Sood

This paper describes the successful development and application of industrial gas turbines using medium-Btu gaseous fuels, including those derived from biodegradation of organic matters found in sanitary landfills and liquid sewage. The effects on the gas turbine and its combustion system of burning these alternate fuels compared to burning high-Btu fuels, along with the gas turbine development required to use alternate fuels from the point of view of combustion process, control system, gas turbine durability, maintainability and safety, are discussed.


1980 ◽  
Vol 102 (2) ◽  
pp. 422-426 ◽  
Author(s):  
J. Odgers ◽  
I. White ◽  
D. Kretschmer

One of the problems facing gas turbine users is the proliferation of gaseous fuels which may be available. These are so many that a comprehensive rig/engine study would be far too costly to undertake. The present studies represent an attempt to quantify the behavior of such fuels, in a simple environment. Measurements of the rates of flame travel and the stability limits have been made for propane/oxygen mixtures diluted with nitrogen, carbon dioxide, helium or argon. The results have been used to forecast the laminar flame speed of mixtures, and rates of flame travel for the various mixtures have been correlated with groups representative of reaction rate and gas transport properties.


Author(s):  
Pontus Eriksson ◽  
Magnus Genrup ◽  
Klas Jonshagen ◽  
Jens Klingmann

Gas turbine systems are predominantly designed to be fuelled with gaseous fuels within a limited Wobbe index range (typically HHV = 45–55 MJ/Nm3 or 1200–1480 Btu/scf). When low calorific fuel gases are fired, the engine will be forced to operate outside its design envelope. The added mass flow will typically raise the cycle pressure ratio and in two-shaft designs also raise the gas generator shaft speed. Typical constraints to be considered due to the altered fuel composition are pressure loads, shaft torques, shaft overspeeds, centrifugal overloading of disks and blades, combustor flameout, surge and flutter limits for the turbomachinery. This poses limitations to usable fuel choices. In this study, the response of a natural gas fired simple cycle two-shaft gas turbine is investigated. A lean premixed combustor is also included in the model. Emphasis has been put on predicting the turbomachinery and combustor behavior as different amounts of N2 or CO2 are added to the fuel path. These two inerts are typically found in large quantities in medium and low calorific fuels. The fuels lower heating value is thus gradually changed from 50 MJ/kg (21.5 kBtu/lb) to 5MJ/kg (2.15 kBtu/lb). A model, based on the Volvo Aero Corp. VT4400 gas turbine (originally Dresser Rand DR990) characterized by one compressor and two expander maps is considered. The free turbine is operated at fixed physical speed. The operating point is plotted in the compressor map and the turbine maps at three distinct firing temperatures representing turndown from full load to bleed opening point. Gas generator speed and shaft power are shown. Surge margin and power turbine power is plotted. Overall efficiency is computed. The behavior of the Volvo lean premixed combustor is also discussed. Air split, primary zone equivalence ratio and temperature is plotted. Combustor loading, combustion intensity and pressure drop is graphed. Results are, as far as possible, given as non-dimensional parameter groups for easy comparison with other machines.


Author(s):  
M. Cadorin ◽  
M. Pinelli ◽  
A. Vaccari ◽  
R. Calabria ◽  
F. Chiariello ◽  
...  

In recent years, the interest in the research on energy production systems fed by biofuels has increased. Gaseous fuels obtained through biomass conversion processes such as gasification, pyrolysis and pyrogasification are generally defined as synthesis gas (syngas). The use of synthesis gas in small-size energy systems, such as those used for distributed micro-cogeneration, has not yet reached a level of technological maturity that could allow a large market diffusion. For this reason, further analyses (both experimental and numerical) have to be carried out to allow these technologies to achieve performance and reliability typical of established technologies based on traditional fuels. In this paper, a numerical analysis of a combustor of a 100-kW micro gas turbine fed by natural gas and biomass-derived synthesis gas is presented. The work has been developed in the framework of a collaboration between the Engineering Department of the University of Ferrara, the Istituto Motori - CNR (Napoli), and Turbec S.p A. of Corporeno di Cento (FE). The main features of the micro gas turbine Turbec T100, located at the Istituto Motori - CNR, are firstly described. A decompression and distribution system allows the feeding of the micro gas turbine with gaseous fuels characterized by different compositions. Moreover, a system of remote monitoring and control together with a data transfer system has been developed in order to set the operative parameters of the machine. The results of the tests performed under different operating conditions are then presented. Subsequently, the paper presents the numerical analysis of a model of the micro gas turbine combustor. The combustor model is validated against manufacturer performance data and experimental data with respect to steady state performance, i.e., average outlet temperature and emission levels. A sensitivity analysis on the model capability to simulate different operating conditions is then performed. The combustor model is used to simulate the combustion of a syngas, composed of different ratios of hydrogen, carbon monoxide, methane, carbon dioxide and water. The results in terms of flame displacement, temperature and emission distribution and values are analyzed and compared to the natural gas simulations. Finally, some simple modifications to the combustion chamber are proposed and simulated both with natural gas and syngas feeding.


Author(s):  
C. F. McDonald

The current energy crisis and substantial increases in the costs of liquid and gaseous fuels, combined with reduced pollutant emission requirements, make the higher efficiency recuperative gas turbine cycle economically attractive for industrial and vehicular application. For future low cost, high temperature, small gas turbines, with improved cycle efficiencies, it is postulated that the complete hot section of the engine (combustor, ducts, turbine nozzle and rotor) will be all ceramic and may include a ceramic heat exchanger. Few of the answers are available today in the areas of ceramic recuperator performance, cost and structural integrity and concentrated development efforts are required to demonstrate the viability of a fixed boundary ceramic gas turbine heat exchanger. This paper briefly outlines possible design and development trends in the areas of exchanger configuration, surface geometry and materials, and it includes specific sizes and economic aspects of ceramic recuperators for future advanced low SFC gas turbines.


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