Chemical Reaction Pathway Analysis of Lean Blowout in a Gas Turbine Combustor

2022 ◽  
Author(s):  
Veeraraghava Raju Hasti ◽  
Jay P. Gore
Keyword(s):  
Gas Turbine ◽  
Chemical Reaction ◽  
Pathway Analysis ◽  
Reaction Pathway ◽  
Gas Turbine Combustor ◽  
Lean Blowout ◽  
Reaction Pathway Analysis

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.

scholarly journals Scale-Resolving Simulation of a Propane-Fuelled Industrial Gas Turbine Combustor Using Finite-Rate Tabulated Chemistry

Fluids ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 126 ◽  
Author(s):  
Kai Zhang ◽  
Ali Ghobadian ◽  
Jamshid M. Nouri
Keyword(s):  
Gas Turbine ◽  
Chemical Reaction ◽  
Turbulent Flame ◽  
Lower Amount ◽  
Combustion Model ◽  
Gas Turbine Combustor ◽  
Finite Rate ◽  
Chemistry Method ◽  
Tabulated Chemistry ◽  
Partially Premixed

The scale-resolving simulation of a practical gas turbine combustor is performed using a partially premixed finite-rate chemistry combustion model. The combustion model assumes finite-rate chemistry by limiting the chemical reaction rate with flame speed. A comparison of the numerical results with the experimental temperature and species mole fraction clearly showed the superiority of the shear stress transport, K-omega, scale adaptive turbulence model (SSTKWSAS). The model outperforms large eddy simulation (LES) in the primary region of the combustor, probably for two reasons. First, the lower amount of mesh employed in the simulation for the industrial-size combustor does not fit the LES’s explicit mesh size dependency requirement, while it is sufficient for the SSTKWSAS simulation. Second, coupling the finite-rate chemistry method with the SSTKWSAS model provides a more reasonable rate of chemical reaction than that predicted by the fast chemistry method used in LES simulation. Other than comparing with the LES data available in the literature, the SSTKWSAS-predicted result is also compared comprehensively with that obtained from the model based on the unsteady Reynolds-averaged Navier–Stokes (URANS) simulation approach. The superiority of the SSTKWSAS model in resolving large eddies is highlighted. Overall, the present study emphasizes the effectiveness and efficiency of coupling a partially premixed combustion model with a scale-resolving simulation method in predicting a swirl-stabilized, multi-jets turbulent flame in a practical, complex gas turbine combustor configuration.

Further understanding the premixed methane/hydrogen/air combustion by global reaction pathway analysis and sensitivity analysis

Fuel ◽  
2020 ◽  
Vol 259 ◽  
pp. 116190 ◽  
Author(s):  
Du Wang ◽  
Changwei Ji ◽  
Shuofeng Wang ◽  
Hao Meng ◽  
Zhe Wang ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Pathway Analysis ◽  
Reaction Pathway ◽  
Global Reaction ◽  
Reaction Pathway Analysis

scholarly journals Experimental Prediction of Lean Blowout Limits for 3kW Micro Gas Turbine Combustor fuelled with LPG

2021 ◽  
Vol 13 (1) ◽  
pp. 89-95
Author(s):  
V. KIRUBAKARAN ◽  
David BHATT
Keyword(s):  
Pressure Drop ◽  
Gas Turbine ◽  
Pressure Loss ◽  
Total Pressure ◽  
Total Pressure Loss ◽  
Gas Turbine Combustor ◽  
Inlet Velocity ◽  
Lean Blowout ◽  
Micro Gas Turbine ◽  
Experimental Prediction

The Lean Blowout Limit of the combustor is one of the important performance parameters for a gas turbine combustor design. This study aims to predict the total pressure loss and Lean Blowout (LBO) limits of an in-house designed swirl stabilized 3kW can-type micro gas turbine combustor. The experimental prediction of total pressure loss and LBO limits was performed on a designed combustor fuelled with Liquefied Petroleum Gas (LPG) for the combustor inlet velocity ranging from 1.70 m/s to 11 m/s. The results show that the predicted total pressure drop increases with increasing combustor inlet velocity, whereas the LBO equivalence ratio decreases gradually with an increase in combustor inlet velocity. The combustor total pressure drop was found to be negligible; being in the range of 0.002 % to 0.065 % for the measured inlet velocity conditions. These LBO limits predictions will be used to fix the operating boundary conditions of the gas turbine combustor.

Inhibition of Premixed Methane-Air Flames with CF3I

2009 ◽  
Vol 4 (3) ◽  
Author(s):  
Caimao Luo ◽  
Bogdan Dlugogorski ◽  
Eric Kennedy ◽  
Behdad Moghtaderi
Keyword(s):  
Sensitivity Analysis ◽  
Pathway Analysis ◽  
Laminar Flame ◽  
Computational Study ◽  
Reaction Pathway ◽  
Burning Velocity ◽  
Flame Velocity ◽  
Promoting Effect ◽  
Elementary Reactions ◽  
Reaction Pathway Analysis

This paper presents a systematic computational study of the inhibition of premixed flames of short chain hydrocarbons with CF3I, focusing on sensitivity analysis of the (normalized) burning velocity and reaction pathway analysis using the "iodine-flux" approach. A comprehensive kinetic mechanism was obtained by combining the GRI, hydrofluorocarbon and CF3I sub-mechanisms, and updating the rates of some of the elementary reactions. Calculations were performed using the PREMIX computer code in the CHEMKIN suite of computer codes. The updated mechanism yielded estimates of the normalized laminar burning velocities which concurs closely with published measurements. The sensitivity analysis resulted in a positive coefficient for CF3I + M ? CF3 + I + M, confirming the promoting effect of CF3I on the laminar flame velocity and is consistent with previous studies. Reaction pathways were drawn for stoichiometric, fuel-lean and fuel-rich flames doped with 1 and 2% of CF3I at atmospheric pressure. The reaction pathway analysis served to identify four major inhibition cycles, denoted as HI ? I ? HI, HI ? I ? I2 ? HI, HI ? I ? CH3I ? HI and HI ? I ? C2H5I ? HI. Furthermore, the paper developed a linear expression linking the normalized rate of heat release with the ratio of laminar burning velocities of mitigated and non-mitigated flames, and verified the efficacy of this expression for flames inhibited with CF3I.

Reaction Pathway Analysis of Homogeneous Dislocation Nucleation in a Perfect Molybdenum Crystal

2011 ◽  
Vol 1297 ◽  
Author(s):  
Hasan A. Saeed ◽  
Satoshi Izumi ◽  
Shotaro Hara ◽  
Shinsuke Sakai
Keyword(s):  
Applied Stress ◽  
Pathway Analysis ◽  
Sampling Method ◽  
Reaction Pathway ◽  
Perfect Crystal ◽  
Dislocation Nucleation ◽  
Stress Range ◽  
Elastic Band ◽  
Burgers Vector ◽  
Reaction Pathway Analysis

ABSTRACTReaction pathway analysis was carried out for homogeneous dislocation nucleation in perfect crystal Mo. The reaction sampling method employed was based on the Nudged Elastic Band algorithm and other extended schemes. Results obtained were compared with corresponding results for Cu and Si. The stress range for activation energies less than 5 eV is found to be considerably higher for Mo than those for Cu as well as Si. Stresses in excess of 12 GPa make homogeneous dislocation nucleation in Mo an unrealistic transition. The results also show the dislocation cores under this stress range to be diffused, with shear displacement of particles being considerably less than the Burgers vector. Depending on the applied stress, displacement of extra slip-plane atoms can be considerable in Mo. This is in contrast to Cu, in which dislocation nucleation is essentially a two-plane phenomenon.

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