A multi-objective CFD optimization of liquid fuel spray injection in dry-low-emission gas-turbine combustors

2017 ◽  
Vol 203 ◽  
pp. 696-710 ◽  
Author(s):  
Behrad Asgari ◽  
Ehsan Amani
Keyword(s):  
Gas Turbine ◽  
Liquid Fuel ◽  
Fuel Spray ◽  
Gas Turbine Combustors ◽  
Multi Objective ◽  
Low Emission ◽  
Cfd Optimization

scholarly journals Evaporation Characteristics of Spray in a Lean Premixed-Prevaporization Combustor for a 100 KW Automotive Ceramic Gas Turbine

1994 ◽  
Author(s):  
Youichlrou Ohkubo ◽  
Yoshinorl Idota ◽  
Yoshihiro Nomura
Keyword(s):  
Gas Turbine ◽  
Mass Fraction ◽  
Liquid Fuel ◽  
Three Dimensional ◽  
Flame Stabilization ◽  
Fuel Spray ◽  
Inlet Temperature ◽  
Lean Combustion ◽  
Swirl Chamber ◽  
Lean Premixed

Spray characteristics of liquid fuel air-assisted atomizers developed for a lean premixed-prevaporization combustor were evaluated under two kinds of conditions: in still air under non-evaporation conditions at atmospheric pressure and in a prevaporization-premixing tube under evaporation conditions with a running gas turbine. The non-evaporated mass fraction of fuel spray was measured using a phase Doppler particle analyzer in the prevaporization-premixing tube, in which the inlet temperature ranged from 873K to 1173K. The evaporation of the fuel spray in the tube is mainly controlled by its atomization and distribution. The NOx emission characteristics measured with a combustor test rig were evaluated with three-dimensional numerical simulations. A low non-evaporated mass fraction of less than 10% was effective in reducing the exhausted NOx from lean premixed-prevaporization combustion to about 1/6 times smaller than that from lean diffusion (spray) combustion. The flow patterns in the combustor are established by a swirl chamber in fuel-air preparation tube, and affect the flame stabilization of lean combustion.

Experimental and Theoretical Studies of a Novel Venturi LPP Combustor

2000 ◽  
Author(s):  
Nils A. Røkke ◽  
Andrew J. W. Wilson
Keyword(s):  
Pressure Drop ◽  
Gas Turbine ◽  
Liquid Fuel ◽  
Gas Generator ◽  
Turbine Engine ◽  
Throat Region ◽  
Low Emission ◽  
Lean Premixed ◽  
Fuel Staging ◽  
Performance And Emissions

A new gas turbine engine using a unique layout patented in Norway has a low emission combustion system under development. The gas generator uses entirely radial rotating components and employs a dual entry LP radial compressor, a radial HP compressor and a radial HP turbine. The power turbine is of a two stage axial design, coupled to an epicyclical gear embedded in the exhaust duct. Several combustor concepts have been tested and evaluated during the development of the engine. The engine is targeted for marine, power generation and train propulsion. For the marine and train application liquid fuel operation is needed, thus the primary focus in the development has been for a lean premixed prevapourised system. An interesting concept utilising two venturi premixers has been studied intensively. By utilising venturi premixers the following advantages can be achieved: • Low overall pressure drop but high injector pressure drop and velocities in the mixing region (throat region) • High shear forces and drag imposed on the droplets enhancing droplet shedding and evaporation • Excellent emission behaviour at designated load conditions Although these advantages can benefit gas turbine low emission combustion the challenges in using venturi premixers are: • Venturis are susceptible to separation and thus flame stabilisation within the venturi which is detrimental • Inlet flow disturbances enhance the tendency for separation in the venturis and must be minimised Studies were launched to investigate a proposed combustor configuration. These studies included analytical studies, Computational Fluid Dynamics (CFD) calculations of isothermal and combusting flow inside the combustor together with rig tests at atmospheric, medium and full pressure. Finally engine tests within the full operating range were conducted with very favourable emission figures for Lean Premixed Prevapourised (LPP) operation. The system was capable of running at below 20 ppm Nox and CO, at elevated power for liquid fuel. Control of part load performance and emissions is by variable fuel staging of the two venturi stages. The paper highlights the features of the venturi combustor development and discusses the characteristics in terms of flow conditions and droplet motion, heat transfer, ignition delay time and emissions.

scholarly journals Investigations of the Working Process in a Dual-Fuel Low-Emission Combustion Chamber for an FPSO Gas Turbine Engine

2020 ◽  
Vol 27 (3) ◽  
pp. 89-99
Author(s):  
Serhiy Serbin ◽  
Badri Diasamidze ◽  
Marek Dzida
Keyword(s):  
Nitrogen Oxides ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Liquid Fuel ◽  
Turbulent Flame ◽  
Dual Fuel ◽  
Working Process ◽  
Fuel Supply ◽  
Low Emission ◽  
Gas Turbine Combustion

AbstractThis investigation is devoted to an analysis of the working process in a dual-fuel low-emission combustion chamber for a floating vessel’s gas turbine. The low-emission gas turbine combustion chamber with partial pre-mixing of fuel and air inside the outer and inner radial-axial swirlers was chosen as the object of research. When modelling processes in a dual-flow low-emission gas turbine combustion chamber, a generalized method is used, based on the numerical solution of the system of conservation and transport equations for a multi-component chemically reactive turbulent system, taking into consideration nitrogen oxides formation. The Eddy-Dissipation-Concept model, which incorporates Arrhenius chemical kinetics in a turbulent flame, and the Discrete Phase Model describing the interfacial interaction are used in the investigation. The obtained results confirmed the possibility of organizing efficient combustion of distillate liquid fuel in a low-emission gas turbine combustion chamber operating on the principle of partial preliminary formation of a fuel-air mixture. Comparison of four methods of liquid fuel supply to the channels of radial-axial swirlers (centrifugal, axial, combined, and radial) revealed the advantages of the radial supply method, which are manifested in a decrease in the overall temperature field non-uniformity at the outlet and a decrease in nitrogen oxides emissions. The calculated concentrations of nitrogen oxides and carbon monoxide at the flame tube outlet for the radial method of fuel supply are 32 and 9.1 ppm, respectively. The results can be useful for further modification and improvement of the characteristics of dual-fuel gas turbine combustion chambers operating with both gaseous and liquid fuels.

Effects of CO2 dilution on combustion instabilities in dual premixed flames

2013 ◽  
Vol 227 (11) ◽  
pp. 2569-2581 ◽  
Author(s):  
Kangyeop Lee ◽  
Hyungmo Kim ◽  
Poomin Park ◽  
Sooseok Yang ◽  
Youngsung Ko
Keyword(s):  
Gas Turbine ◽  
Coupling Strength ◽  
Mass Fraction ◽  
Combustion Instability ◽  
Flame Structure ◽  
Fuel Mass ◽  
Gas Turbine Combustors ◽  
Low Emission ◽  
Pilot Fuel ◽  
Fuel Mass Fraction

There has been a rapid increase in the demand for biogas applications in recent years, and dry low NOx and dry low emission gas turbine combustors are promising platforms for such applications. Combustion instability is the most important drawback in dry low NOx gas turbine combustors and has, therefore, attracted considerable research interest lately. As a fundamental study towards the use of biogas in dry low NOx and dry low emission gas turbine combustors, this article investigates the influence of CO2 in surrogate biogas on combustion instability. Tests were conducted using a dry low NOx type, a dual lean premixed gas turbine combustor. For a dual flame with dual swirl, the pilot fuel mass fraction affects the flame structure, and the flame structure, in turn, determines the temperature distribution in the combustion chamber and the combustion instability. The effects of the pilot fuel mass fraction, which is an important parameter of the combustor, and the CO2 dilution rate, which is a major contributor of biogas combustion, on the combustion characteristics and instability are investigated through dynamic pressure signal and phase-resolved OH* images. Combustion instability decreases for higher CO2 dilution rates, whose effects depend on the pilot fuel mass fraction. The instability reaches its maximum at a pilot fuel mass fraction of 0.3. Tests confirm that combustion instability diminishes with CO2 dilution, as it reduces the perturbation in the heat emission, and the flame speed decreases resulting in a greater flame surface or volume. Further, investigation of the Rayleigh Index, which represents the coupling strength of the heat release fluctuation and the natural frequency, shows that CO2 dilution weakens the coupling strength, resulting in less combustion instability.

Experimental and Theoretical Studies of a Novel Venturi Lean Premixed Prevaporized (LPP) Combustor

2000 ◽  
Vol 123 (3) ◽  
pp. 567-573 ◽  
Author(s):  
N. A. Ro̸kke ◽  
A. J. W. Wilson
Keyword(s):  
Pressure Drop ◽  
Gas Turbine ◽  
Liquid Fuel ◽  
Flame Stabilization ◽  
Gas Generator ◽  
Throat Region ◽  
Low Emission ◽  
Lean Premixed ◽  
Fuel Staging ◽  
Performance And Emissions

A new gas turbine engine using a unique layout patented in Norway has a low-emission combustion system under development. The gas generator uses entirely radial rotating components and employs a dual entry LP radial compressor, a radial HP compressor, and a radial HP turbine. The power turbine is of a two-stage axial design, coupled to an epicyclical gear embedded in the exhaust duct. Several combustor concepts have been tested and evaluated during the development of the engine. The engine is targeted for marine, power generation, and train propulsion. For the marine and train application liquid fuel operation is needed, thus the primary focus in the development has been for a lean premixed prevapourised system. An interesting concept utilizing two venturi premixers has been studied intensively. By utilizing venturi premixers the following advantages can be achieved: (1) low overall pressure drop but high injector pressure drop and velocities in the mixing region (throat region), (2) high shear forces and drag imposed on the droplets enhancing droplet shedding and evaporation, and (3) excellent emission behavior at designated load conditions. Although these advantages can benefit gas turbine low-emission combustion, the challenges in using venturi premixers are: (1) venturis are susceptible to separation and thus flame stabilization within the venturi which is detrimental and (2) inlet flow disturbances enhance the tendency for separation in the venturis and must be minimized. Studies were launched to investigate a proposed combustor configuration. These studies included analytical studies, computational fluid dynamics (CFD) calculations of isothermal and combusting flow inside the combustor together with rig tests at atmospheric, medium, and full pressure. Finally, engine tests within the full operating range were conducted with very favorable emission figures for lean premixed prevaporized (LPP) operation. The system was capable of running at below 20 ppm NOx and CO, at elevated power for liquid fuel. Control of part load performance and emissions is by variable fuel staging of the two venturi stages. The paper highlights the features of the venturi combustor development and discusses the characteristics in terms of flow conditions and droplet motion, heat transfer, ignition delay time, and emissions.

ORGANIZATION OF LOW-EMISSION COMBUSTION OF FUEL-LEAN KEROSENE-AIR MIXTURES IN GAS-TURBINE COMBUSTORS

2020 ◽  
Author(s):  
E. D. Sverdlov ◽  
◽  
A. N. Dubovitskii ◽  
A. V. Lebedev ◽  
K. I. Spiridonov ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Gas Turbine Combustors ◽  
Low Emission ◽  
Industrial Gas Turbines

The article describes a principle developed by the present authors for low- emission combustion of “lean” kerosene-air mixtures in the low-emission combustor designed for Industrial Gas Turbines. The design of the low-emission combustor with multiple kerosene jets is described.

NUMERICAL AND EXPERIMENTAL INVESTIGATIONS OF UNSTABLE COMBUSTION IN LOW-EMISSION GAS-TURBINE COMBUSTORS

2020 ◽  
Author(s):  
E. D. Sverdlov ◽  
◽  
A. N. Dubovitskii ◽  
K. Ya. Yakubovskiy ◽  
N. S. Galimov ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Unsteady Combustion ◽  
Flow Swirling ◽  
Gas Turbine Combustors ◽  
Combustion Modes ◽  
Low Emission ◽  
Unstable Combustion

The paper presents the calculation and experimental results for investigated unsteady combustion modes in low-emission combustors operating without flow swirling and developed by the present authors.

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