Erratum: “Extension of the Combustion Stability Range in Dry Low NOx Lean Premixed Gas Turbine Combustor Using a Fuel Rich Annular Pilot Burner” [ASME J. Eng. Gas Turbines Power, 2014, 136(5), p. 051509, DOI: 10.1115/1.4026186]

2014 ◽  
Vol 136 (8) ◽  
Author(s):  
L. Rosentsvit
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Stability ◽  
Gas Turbine Combustor ◽  
Stability Range ◽  
Lean Premixed ◽  
Pilot Burner

Extension of the Combustion Stability Range in Dry Low NOx Lean Premixed Gas Turbine Combustor Using a Fuel Rich Annular Pilot Burner

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
L. Rosentsvit ◽  
Y. Levy ◽  
V. Erenburg ◽  
V. Sherbaum ◽  
V. Ovcharenko ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Combustion Zone ◽  
Combustion Instability ◽  
Experimental Results ◽  
Nox Emission ◽  
Combustion Stability ◽  
Stability Range ◽  
Numerical Effort ◽  
Lean Premixed ◽  
Pilot Burner

The present work is concerned with improving combustion stability in lean premixed (LP) gas turbine combustors by injecting free radicals into the combustion zone. The work is a joint experimental and numerical effort aimed at investigating the feasibility of incorporating a circumferential pilot combustor, which operates under rich conditions and directs its radicals enriched exhaust gases into the main combustion zone as the means for stabilization. The investigation includes the development of a chemical reactors network (CRN) model that is based on perfectly stirred reactors modules and on preliminary CFD analysis as well as on testing the method on an experimental model under laboratory conditions. The study is based on the hypothesis that under lean combustion conditions, combustion instability is linked to local extinctions of the flame and consequently, there is a direct correlation between the limiting conditions affecting combustion instability and the lean blowout (LBO) limit of the flame. The experimental results demonstrated the potential reduction of the combustion chamber's LBO limit while maintaining overall NOx emission concentration values within the typical range of low NOx burners and its delicate dependence on the equivalence ratio of the ring pilot flame. A similar result was revealed through the developed CHEMKIN-PRO CRN model that was applied to find the LBO limits of the combined pilot burner and main combustor system, while monitoring the associated emissions. Hence, both the CRN model, and the experimental results, indicate that the radicals enriched ring jet is effective at stabilizing the LP flame, while keeping the NOx emission level within the characteristic range of low NOx combustors.

Reactor Network Modeling of Stability and Emissions of Hydrogen and Natural Gas Blends for a Piloted Gas Turbine Combustor

2020 ◽  
Author(s):  
Candy Hernandez ◽  
Vincent McDonell
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Chemical Reactor ◽  
Experimental Results ◽  
Fuel Composition ◽  
Gas Turbine Combustor ◽  
Flammability Limits ◽  
Lean Premixed ◽  
Carbon Molecules

Abstract Lean-premixed (LPM) gas turbines have been developed for stationary power generation in efforts to reduce emissions due to strict air quality standards. Lean-premixed operation is beneficial as it reduces combustor temperatures, thus decreasing NOx formation and unburned hydrocarbons. However, tradeoffs occur between system performance and turbine emissions. Efforts to minimize tradeoffs between stability and emissions include the addition of hydrogen to natural gas, a common fuel used in stationary gas turbines. The addition of hydrogen is promising for both increasing combustor stability and further reducing emissions because of its wide flammability limits allowing for lower temperature operation, and lack of carbon molecules. Other efforts to increase gas turbine stability include the usage of a non-lean pilot flame to assist in stabilizing the main flame. By varying fuel composition for both the main and piloted flows of a gas turbine combustor, the effect of hydrogen addition on performance and emissions can be systematically evaluated. In the present work, computational fluid dynamics (CFD) and chemical reactor networks (CRN) are created to evaluate stability (LBO) and emissions of a gas turbine combustor by utilizing fuel and flow rate conditions from former hydrogen and natural gas experimental results. With CFD and CRN analysis, the optimization of parameters between fuel composition and main/pilot flow splits can provide feedback for minimizing pollutants while increasing stability limits. The results from both the gas turbine model and former experimental results can guide future gas turbine operation and design.

Modelling of NOx Formation of a Premixed DLE Gas Turbine Combustor

2001 ◽  
Author(s):  
R. L. G. M. Eggels
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
State Equation ◽  
Gas Turbine Combustor ◽  
Nox Formation ◽  
No Formation ◽  
Emission Regulations ◽  
Lean Premixed ◽  
Industrial Gas Turbines ◽  
Two Stages

To comply with the stringent emission regulations industrial gas turbines operate under lean premixed conditions. To be able to predict emissions in an early design phase, advanced premixed combustion models are required. The rate of NOx formation is sensitive to temperature and some radical concentrations, therefore the flame predictions have to be accurate and detailed. It is well known that there are several routes (thermal, prompt, N2O mechanism) by which NOx can be formed. As lean premixed gas turbines operate at relative low flame temperatures, the contribution of the prompt NO and N2O mechanisms has to be accounted for. The modelling of NOx formation is done in a post-processor, as the influence of nitrogen species on the main combustion characteristics is negligible. This post-processor is based on flame calculations using a Flame Generated Manifold method. This is a reduced reaction mechanism, so that only a limited number of variables have to be solved during the CFD computations. A post-processor method has been developed to compute NO formation. Differential equations are solved for NO and N2O, other species including nitrogen are solved using a steady-state equation. The flame and post-processor models are applied to 2-D and 3-D models of an industrial series staged gas turbine. Parameter studies for the fuel split between the two stages and inlet fuel/air ratio variations have been carried out and the data has been compared with generic engine data.

Thermal Incineration of VOCs in a Jet-Stabilized Micro Gas Turbine Combustor

2015 ◽  
Author(s):  
A. Schwärzle ◽  
T. O. Monz ◽  
M. Aigner
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Flame Temperature ◽  
Total Efficiency ◽  
Gas Turbine Combustor ◽  
Stability Range ◽  
Iccd Camera ◽  
Gas Treatment ◽  
Micro Gas Turbine ◽  
Air Stream

Using gas turbines for waste gas treatment is a promising technology compared to other thermal oxidizing systems in terms of total efficiency, due to the combined heat and power production. In this work, experiments have been carried out where an air stream containing volatile organic compounds (VOCs) is fed to a micro gas turbine combustor which is co-fired using natural gas. All experiments were conducted at atmospheric pressure. For lower preheat temperatures, the equivalence ratio of the pilot stage was step-wise increased at constant global air to fuel ratios to further extend the operation limit. The VOC destruction efficiency of the burner is analyzed for various oxygenated VOCs and concentrations with a maximum lower heating value of the VOC containing air stream of 0.25 MJ/Nm3. The stability range of the burner is presented for various equivalence ratios with a global volumetric heat release up to 33 MW/m3 and air preheat temperatures up to 650 °C. The flame is analyzed in terms of shape, length and lift-off height, using the OH* chemiluminescence signal detected by an ICCD-camera. At same air numbers, changes on the flame are insignificant to the different VOCs in most cases. Regarding the emissions of NOx, the VOC containing air is beneficial at all air numbers, while a decrease in CO is only observed for lower air numbers. A minimum of CO emissions for both preheat temperatures is obtained at an adiabatic flame temperature of 1671 K.

Numerical Investigation of the Pressure Effect on the NOx Formation in a Lean-Premixed Gas Turbine Combustor

2021 ◽  
Vol 35 (8) ◽  
pp. 6776-6784
Author(s):  
Truc Huu Nguyen ◽  
Jungkyu Park ◽  
Changhun Sin ◽  
Seungchai Jung ◽  
Shaun Kim
Keyword(s):  
Numerical Investigation ◽  
Gas Turbine ◽  
Pressure Effect ◽  
Gas Turbine Combustor ◽  
Nox Formation ◽  
Lean Premixed

Combustion Technology for Low-Emissions Gas-Turbines: Some Recent Modeling Results

1996 ◽  
Vol 118 (3) ◽  
pp. 201-208 ◽  
Author(s):  
S. M. Correa ◽  
I. Z. Hu ◽  
A. K. Tolpadi
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Spectroscopic Data ◽  
Physical Models ◽  
Gas Turbine Combustor ◽  
Finite Rate ◽  
Recent Developments ◽  
Combustion Technology ◽  
Computationally Intensive ◽  
Transport Method

Computer modeling of low-emissions gas-turbine combustors requires inclusion of finite-rate chemistry and its intractions with turbulence. The purpose of this review is to outline some recent developments in and applications of the physical models of combusting flows. The models reviewed included the sophisticated and computationally intensive velocity-composition pdf transport method, with applications shown for both a laboratory flame and for a practical gas-turbine combustor, as well as a new and computationally fast PSR-microstructure-based method, with applications shown for both premixed and nonpremixed flames. Calculations are compared with laserbased spectroscopic data where available. The review concentrates on natural-gas-fueled machines, and liquid-fueled machines operating at high power, such that spray vaporization effects can be neglected. Radiation and heat transfer is also outside the scope of this review.

scholarly journals The Effect of Discrete Pilot Hydrogen Dopant Injection on the Lean Blowout Performance of a Model Gas Turbine Combustor

1999 ◽  
Author(s):  
Oanh Nguyen ◽  
Scott Samuelsen
Keyword(s):  
Gas Turbine ◽  
Atmospheric Pressure ◽  
Gas Turbines ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Lean Blowout ◽  
Lean Combustion ◽  
Attractive Option ◽  
Overall Performance ◽  
Model Gas Turbine Combustor

In view of increasingly stringent NOx emissions regulations on stationary gas turbines, lean combustion offers an attractive option to reduce reaction temperatures and thereby decrease NOx production. Under lean operation, however, the reaction is vulnerable to blowout. It is herein postulated that pilot hydrogen dopant injection, discretely located, can enhance the lean blowout performance without sacrificing overall performance. The present study addresses this hypothesis in a research combustor assembly, operated at atmospheric pressure, and fired on natural gas using rapid mixing injection, typical of commercial units. Five hydrogen injector scenarios are investigated. The results show that (1) pilot hydrogen dopant injection, discretely located, leads to improved lean blowout performance and (2) the location of discrete injection has a significant impact on the effectiveness of the doping strategy.

Experimental and numerical study of flame structure and emissions in a micro gas turbine combustor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vedant Dwivedi ◽  
Srikanth Hari ◽  
S. M. Kumaran ◽  
B. V. S. S. S. Prasad ◽  
Vasudevan Raghavan
Keyword(s):  
Gas Turbine ◽  
Rural Areas ◽  
Gas Turbines ◽  
Alternative Fuels ◽  
Numerical Study ◽  
Operating Conditions ◽  
Emission Characteristics ◽  
Nitric Oxides ◽  
Gas Turbine Combustor ◽  
Micro Gas Turbine

Abstract Experimental and numerical study of flame and emission characteristics in a tubular micro gas turbine combustor is reported. Micro gas turbines are used for distributed power (DP) generation using alternative fuels in rural areas. The combustion and emission characteristics from the combustor have to be studied for proper design using different fuel types. In this study methane, representing fossil natural gas, and biogas, a renewable fuel that is a mixture of methane and carbon-dioxide, are used. Primary air flow (with swirl component) and secondary aeration have been varied. Experiments have been conducted to measure the exit temperatures. Turbulent reactive flow model is used to simulate the methane and biogas flames. Numerical results are validated against the experimental data. Parametric studies to reveal the effects of primary flow, secondary flow and swirl have been conducted and results are systematically presented. An analysis of nitric-oxides emission for different fuels and operating conditions has been presented subsequently.

Flame Response Mechanisms Due to Velocity Perturbations in a Lean Premixed Gas Turbine Combustor

2010 ◽  
Vol 133 (2) ◽  
Author(s):  
Brian Jones ◽  
Jong Guen Lee ◽  
Bryan D. Quay ◽  
Domenic A. Santavicca
Keyword(s):  
Transfer Function ◽  
Heat Release ◽  
Gas Turbine ◽  
Velocity Fluctuation ◽  
Gas Turbine Combustor ◽  
Velocity Fluctuations ◽  
Inlet Velocity ◽  
Lean Premixed ◽  
Flame Response ◽  
Second Peak

The response of turbulent premixed flames to inlet velocity fluctuations is studied experimentally in a lean premixed, swirl-stabilized, gas turbine combustor. Overall chemiluminescence intensity is used as a measure of the fluctuations in the flame’s global heat release rate, and hot wire anemometry is used to measure the inlet velocity fluctuations. Tests are conducted over a range of mean inlet velocities, equivalence ratios, and velocity fluctuation frequencies, while the normalized inlet velocity fluctuation (V′/Vmean) is fixed at 5% to ensure linear flame response over the employed modulation frequency range. The measurements are used to calculate a flame transfer function relating the velocity fluctuation to the heat release fluctuation as a function of the velocity fluctuation frequency. At low frequency, the gain of the flame transfer function increases with increasing frequency to a peak value greater than 1. As the frequency is further increased, the gain decreases to a minimum value, followed by a second smaller peak. The frequencies at which the gain is minimum and achieves its second peak are found to depend on the convection time scale and the flame’s characteristic length scale. Phase-synchronized CH∗ chemiluminescence imaging is used to characterize the flame’s response to inlet velocity fluctuations. The observed flame response can be explained in terms of the interaction of two flame perturbation mechanisms, one originating at flame-anchoring point and propagating along the flame front and the other from vorticity field generated in the outer shear layer in the annular mixing section. An analysis of the phase-synchronized flame images show that when both perturbations arrive at the flame at the same time (or phase), they constructively interfere, producing the second peak observed in the gain curves. When the perturbations arrive at the flame 180 degrees out-of-phase, they destructively interfere, producing the observed minimum in the gain curve.

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