scholarly journals Direct numerical simulation of flame stabilization assisted by autoignition in a reheat gas turbine combustor

2019 ◽  
Vol 37 (2) ◽  
pp. 2635-2642 ◽  
Author(s):  
Konduri Aditya ◽  
Andrea Gruber ◽  
Chao Xu ◽  
Tianfeng Lu ◽  
Alex Krisman ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Gas Turbine ◽  
Flame Stabilization ◽  
Gas Turbine Combustor

scholarly journals Detailed Examination of a Modified Two-Stage Micro Gas Turbine Combustor

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Andreas Schwärzle ◽  
Thomas O. Monz ◽  
Andreas Huber ◽  
Manfred Aigner
Keyword(s):  
Gas Turbine ◽  
Detailed Examination ◽  
Flame Stabilization ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Two Stage ◽  
Micro Gas Turbine ◽  
Previous Design ◽  
Recirculation Zones ◽  
Asme Paper

Jet-stabilized combustion is a promising technology for fuel flexible, reliable, highly efficient combustion systems. The aim of this work is a reduction of NOx emissions of a previously published two-stage micro gas turbine (MGT) combustor (Zanger et al., 2015, “Experimental Investigation of the Combustion Characteristics of a Double-Staged FLOX-Based Combustor on an Atmospheric and a Micro Gas Turbine Test Rig,” ASME Paper No. GT2015-42313 and Schwärzle et al., 2016, “Detailed Examination of Two-Stage Micro Gas Turbine Combustor,” ASME Paper No. GT2016-57730), where the pilot stage (PS) of the combustor was identified as the main contributor to NOx emissions. The geometry optimization was carried out regarding the shape of the pilot dome and the interface between PS and main stage (MS) in order to prevent the formation of high-temperature recirculation zones. Both stages have been run separately to allow a detailed understanding of the flame stabilization within the combustor, its range of stable combustion, the interaction between both stages, and the influence of the modified geometry. All experiments were conducted at atmospheric pressure and an air preheat temperature of 650  °C. The flame was analyzed in terms of shape, length, and lift-off height, using OH* chemiluminescence (OH-CL) images. Emission measurements for NOx, CO, and unburned hydrocarbons (UHC) emissions were carried out. At a global air number of λ = 2, a fuel split variation was carried out from 0 (only PS) to 1 (only MS). The modification of the geometry leads to a decrease in NOx and CO emissions throughout the fuel split variation in comparison with the previous design. Regarding CO emissions, the PS operations are beneficial for a fuel split above 0.8. The local maximum in NOx emissions observed for the previous combustor design at a fuel split of 0.78 was not apparent for the modified design. NOx emissions were increasing, when the local air number of the PS was below the global air number. In order to evaluate the influence of the modified design on the flow field and identify the origin of the emission reduction compared to the previous design, unsteady Reynolds-averaged Navier–Stokes simulations were carried out for both geometries at fuel splits of 0.93 and 0.78, respectively, using the DLR (German Aerospace Center) in-house code turbulent heat release extension of the tau code (theta) with the k–ω shear stress transport turbulence model and the DRM22 (Kazakov and Frenklach, 1995, “DRM22,” University of California at Berkeley, Berkeley, CA, accessed Sept. 21, 2017, http://www.me.berkeley.edu/drm/) detailed reaction mechanism. The numerical results showed a strong influence of the recirculation zones on the PS reaction zone.

Direct Numerical Simulation Study of an Experimental Lifted H2/N2 Flame. Part 2: Flame Stabilization

2012 ◽  
Vol 26 (8) ◽  
pp. 4830-4839 ◽  
Author(s):  
Haiou Wang ◽  
Kun Luo ◽  
Fuxing Yi ◽  
Jianren Fan
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Simulation Study ◽  
Flame Stabilization

Numerical simulation of a low-emission gas turbine combustor using KIVA-II

1992 ◽  
Vol 15 (8) ◽  
pp. 865-881 ◽  
Author(s):  
S. L. Yang ◽  
R. Chen ◽  
M. C. Cline ◽  
H. L. Nguyen ◽  
G. J. Micklow
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
Gas Turbine Combustor ◽  
Low Emission

Numerical Simulation for the Preliminary Design of Fuel Flexible Stationary Gas Turbine Combustors Using Conventional and Alternative Fuels

2012 ◽  
Author(s):  
Washington Orlando Irrazabal Bohorquez ◽  
João Roberto Barbosa ◽  
Rob Johan Maria Bastiaans ◽  
Philip de Goey
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Alternative Fuels ◽  
High Efficiency ◽  
Numerical Study ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Gas Turbine Combustor ◽  
Primary Zone

Currently, high efficiency and low emissions are most important requisites for the design of modern gas turbines due to the strong environmental restrictions around the world. In the past years, alternative fuels have been considered for application in industrial gas turbines. Therefore, combustor performance, pollutant emissions and the ability to burn several fuels became of much concern and high priority has been given to the combustor design. This paper describes a methodology focused on the design of stationary gas turbines combustion chambers with the ability to efficiently burn conventional and alternative fuels. A simplified methodology is used for the calculations of the equilibrium temperature and chemical species in the primary zone of a gas turbine combustor. Direct fuel injection and diffusion flames, together with numerical methods like Newton-Raphson, LU Factorization and Lagrange Polynomials, are used for the calculations. Diesel, ethanol and methanol fuels were chosen for the numerical study. A computer code sequentially calculates the main geometry of the combustor. From the numerical simulation it is concluded that the basic gas turbine combustor geometry, for some operating conditions and burning diesel, ethanol or methanol, are of similar sizes, because the development of aerodynamic characteristics predominate over the thermochemical properties. It is worth to note that the type of fuel has a marked effect on the stability and combustion advancement in the combustor. This can be seen when the primary zone is analyzed under a steady-state operating condition. At full power, the pressure is 1.8 MPa and the temperature 1,000 K at the combustor inlet. Then, the equivalence ratios in the primary zone are 1.3933 (diesel), 1.4352 (ethanol) and 1.3977 (methanol) and the equilibrium temperatures for the same operating conditions are 2,809 K (diesel), 2,754 K (ethanol) and 2,702 K (methanol). This means that the combustor can reach similar flame stability conditions, whereas the combustion efficiency will require richer fuel/air mixtures of ethanol or methanol are burnt instead of diesel. Another important result from the numerical study is that the concentration of the main pollutants (CO, CO2, NO, NO2) is reduced when ethanol or methanol are burnt, in place of diesel.

scholarly journals Technical Applicability of Low-Swirl Fuel Nozzle for a Liquid-Fueled Industrial Gas Turbine Combustor

2012 ◽  
Author(s):  
Masamichi Koyama ◽  
Shigeru Tachibana
Keyword(s):  
Gas Turbine ◽  
Flow Characteristics ◽  
Axial Direction ◽  
Flame Stabilization ◽  
Axial Position ◽  
Axial Distance ◽  
Gas Turbine Combustor ◽  
Lifted Flame ◽  
Fuel Nozzle ◽  
Industrial Gas Turbine

This paper explores the technical applicability of a low-swirl fuel nozzle designed for use with a liquid-fueled industrial gas turbine combustor. Particle image velocimetry was applied to measure nozzle flow fields with an open methane-air premixed flame configuration. Herein we discuss the effects of the chamfer dimensions of the nozzle tip on flow characteristics. The profiles indicate parallel shifts in axial direction that depend on chamfer dimensions. When velocity is normalized by bulk velocity and plotted against axial distance from the virtual origins, the profiles are consistent. This means that chamfer dimensions primarily affect the axial position of the flame, while keeping other flow characteristics, such as global stretch rate, unchanged. Then, the atmospheric combustion test was conducted with kerosene in a single-can combustor. Lifted flame stabilization was confirmed by observing the flames through a window. Lastly, an engine test was performed to assess the technical applicability of the fuel nozzle under real engine conditions. The engine testbed was a 290 kW simple-cycle liquid-fueled gas turbine engine. The configurations of the fuel nozzle were consistent with the ones used in the PIV and the atmospheric combustion test. Wall temperatures close to the fuel nozzle exit were within the acceptable range, even without the cooling air required with conventional combustors. This is an advantage of the lifted flame stabilization technique. NOx emissions were below maximum levels set under current Japanese regulations (<84 ppm@15% O2). In sum, the proposed fuel nozzle design shows promise for use with liquid-fueled industrial gas turbine engines.

Correction: Numerical Simulation of Flow Distribution in a Realistic Gas Turbine Combustor

2018 ◽  
Author(s):  
Veeraraghava Raju Hasti ◽  
Prithwish Kundu ◽  
Gaurav Kumar ◽  
Scott A. Drennan ◽  
Sibendu Som ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
Flow Distribution ◽  
Gas Turbine Combustor
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