scholarly journals A Semi-Analytical Finite Rate Two-Reactor Model for Gas Turbine Combustors

1997 ◽  
Author(s):  
J. H. Tonouchi ◽  
T. J. Held ◽  
H. C. Mongia
Keyword(s):  
Gas Turbine ◽  
Flow Reactor ◽  
Plug Flow ◽  
Aircraft Engine ◽  
Frequency Function ◽  
Reactor Model ◽  
Finite Rate ◽  
Gas Turbine Combustors ◽  
Primary Zone ◽  
Definition Of

A gas turbine combustor is modeled using a two-reactor, finite-rate mixing and chemistry gas particle approach. The first reactor, used to simulate combustion in the primary zone, permits independent definition of the rates of macromixing and micromixing within the reactor, and the amount of premixing of fuel and air entering the reactor. Finite-rate macromixing is simulated by consideration of the fluid particle residence time distribution frequency function and the ages of the particles in the reactor. Finite-rate micromixing is simulated using a modified Coalescence-Dispersion (C-D) model. The second reactor model simulates combustion in the dilution zone of the combustor, and is modeled as a plug flow reactor with cross-flowing jets of dilution air and co-flowing streams of cooling film air. The primary zone reactor model predicts physically reasonable trends in mean temperature, and CO and NOx emissions as the macromixing and micromixing parameters are varied with respect to the perfectly-stirred reactor limit. The model also has shown to predict the correct trends in modeling NOx and CO emissions from aircraft engine gas turbine combustors.

A Semi-Analytical Finite Rate Two-Reactor Model for Gas Turbine Combustors

1998 ◽  
Vol 120 (3) ◽  
pp. 495-501 ◽  
Author(s):  
J. H. Tonouchi ◽  
T. J. Held ◽  
H. C. Mongia
Keyword(s):  
Gas Turbine ◽  
Flow Reactor ◽  
Plug Flow ◽  
Aircraft Engine ◽  
Frequency Function ◽  
Reactor Model ◽  
Finite Rate ◽  
Gas Turbine Combustors ◽  
Primary Zone ◽  
Definition Of

A gas turbine combustor is modeled using a two-reactor, finite-rate mixing and chemistry gas particle approach. The first reactor, used to simulate combustion in the primary zone, permits independent definition of the rates of macromixing and micromixing within the reactor, and the amount of premixing of fuel and air entering the reactor. Finite-rate macromixing is simulated by consideration of the fluid particle residence time distribution frequency function and the ages of the particles in the reactor. Finite-rate micromixing is simulated using a modified Coalescence-Dispersion (C-D) model. The second reactor model simulates combustion in the dilution zone of the combustor, and is modeled as a plug flow reactor with cross-flowing jets of dilution air and co-flowing streams of cooling film air. The primary zone reactor model predicts physically reasonable trends in mean temperature, and CO and NOx emissions as the macromixing and micromixing parameters are varied with respect to the perfectly stirred reactor limit. The model also has shown to predict the correct trends in modeling NOx and CO emissions from aircraft engine gas turbine combustors.

Effects of Hydrogen Fueling on NOx Emissions: A Reactor Model Approach for an Industrial Gas Turbine Combustor

2017 ◽  
Author(s):  
D. Kroniger ◽  
M. Lipperheide ◽  
M. Wirsum
Keyword(s):  
Gas Turbine ◽  
Flow Reactor ◽  
Plug Flow ◽  
Nox Emissions ◽  
Flame Zone ◽  
Gas Turbine Combustor ◽  
Reactor Model ◽  
Stirred Reactor ◽  
Set Up ◽  
Reactor Network

Addition of hydrogen (H2) to gas turbine fuel has recently become a topic of interest facing the global challenges of CO2 free combustion. As a drawback, Nitrogen oxide (NOx) emissions are likely to increase in hydrogen-rich fuel combustion which in return limits the use of the technology. In the course of this development, a model-based quantification of NOx emission increase by fuel flexibility may identify possible operation ranges of this technology. This paper evaluates the effect of an increased hydrogen fraction in the fuel on the NOx emissions of a non-premixed 10 MWth gas turbine combustor. A simple reactor network model has been set up using a perfectly stirred reactor (PSR) to simulate the flame zone and a plug flow reactor (PFR) to simulate the post flame zone. The change of residence time in the flame zone is accounted for by an empirical expression. The model is validated against data from high-pressure test rig experiments of an industrial non-premixed gas turbine combustor. The model results are in good agreement with the experimental data. Based on the model results, a fundamental correlation of the effect of hydrogen on the NOx emissions is formulated.

Chemical Kinetic Analysis of a Flameless Gas Turbine Combustor

2008 ◽  
Author(s):  
G. Arvind Rao ◽  
Yeshayahou Levy ◽  
Ephraim J. Gutmark
Keyword(s):  
Combustion Chamber ◽  
Kinetic Analysis ◽  
Gas Turbine ◽  
Flame Temperature ◽  
Plug Flow ◽  
Combustion Process ◽  
Chemical Reactor ◽  
Chemical Kinetic ◽  
Combustion Regime ◽  
Reactor Model

Flameless combustion (FC) is one of the most promising techniques of reducing harmful emissions from combustion systems. FC is a combustion phenomenon that takes place at low O2 concentration and high inlet reactant temperature. This unique combination results in a distributed combustion regime with a lower adiabatic flame temperature. The paper focuses on investigating the chemical kinetics of an prototype combustion chamber built at the university of Cincinnati with an aim of establishing flameless regime and demonstrating the applicability of FC to gas turbine engines. A Chemical reactor model (CRM) has been built for emulating the reactions within the combustor. The entire combustion chamber has been divided into appropriate number of Perfectly Stirred Reactors (PSRs) and Plug Flow Reactors (PFRs). The interconnections between these reactors and the residence times of these reactors are based on the PIV studies of the combustor flow field. The CRM model has then been used to predict the combustor emission profile for various equivalence ratios. The results obtained from CRM model show that the emission from the combustor are quite less at low equivalence ratios and have been found to be in reasonable agreement with experimental observations. The chemical kinetic analysis gives an insight on the role of vitiated combustion gases in suppressing the formation of pollutants within the combustion process.

scholarly journals Reversible Molten Catalytic Methane Cracking Applied to Commercial Solar-Thermal Receivers

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6229
Author(s):  
Scott C. Rowe ◽  
Taylor A. Ariko ◽  
Kaylin M. Weiler ◽  
Jacob T. E. Spana ◽  
Alan W. Weimer
Keyword(s):  
Flow Reactor ◽  
Plug Flow ◽  
Hydrogen Fuel ◽  
Reactor Model ◽  
Solar Reactor ◽  
Greenhouse Emissions ◽  
Solar Reactors ◽  
And Performance ◽  
Methane Cracking ◽  
Technology Demonstrator

When driven by sunlight, molten catalytic methane cracking can produce clean hydrogen fuel from natural gas without greenhouse emissions. To design solar methane crackers, a canonical plug flow reactor model was developed that spanned industrially relevant temperatures and pressures (1150–1350 Kelvin and 2–200 atmospheres). This model was then validated against published methane cracking data and used to screen power tower and beam-down reactor designs based on “Solar Two,” a renewables technology demonstrator from the 1990s. Overall, catalytic molten methane cracking is likely feasible in commercial beam-down solar reactors, but not power towers. The best beam-down reactor design was 9% efficient in the capture of sunlight as fungible hydrogen fuel, which approaches photovoltaic efficiencies. Conversely, the best discovered tower methane cracker was only 1.7% efficient. Thus, a beam-down reactor is likely tractable for solar methane cracking, whereas power tower configurations appear infeasible. However, the best simulated commercial reactors were heat transfer limited, not reaction limited. Efficiencies could be higher if heat bottlenecks are removed from solar methane cracker designs. This work sets benchmark conditions and performance for future solar reactor improvement via design innovation and multiphysics simulation.

Combustion Air Jet Influence on Primary Zone Characteristics for Gas-Turbine Combustors

2002 ◽  
Vol 18 (2) ◽  
pp. 407-416 ◽  
Author(s):  
S. Gogineni ◽  
D. Shouse ◽  
C. Frayne ◽  
J. Stutrud ◽  
G. Sturgess
Keyword(s):  
Gas Turbine ◽  
Gas Turbine Combustors ◽  
Air Jet ◽  
Primary Zone

A Kinetic Study of Hydrocarbons Reactivity on Palladium Catalysts through a DFT Approach

2001 ◽  
Vol 677 ◽  
Author(s):  
Valeria Bertani ◽  
Carlo Cavallotti ◽  
Maurizio Masi ◽  
Sergio Carrá
Keyword(s):  
Kinetic Study ◽  
Palladium Catalysts ◽  
Density Functional ◽  
Flow Reactor ◽  
Correlation Energy ◽  
Plug Flow ◽  
Kinetic Scheme ◽  
Atomic Scale ◽  
Basis Set ◽  
Reactor Model

ABSTRACTPalladium clusters have been chosen to represent a typical supported heterogeneous catalyst and their interaction with hydrocarbons has been investigated theoretically. The calculations were performed through density functional theory and the Becke-Lee-Yang-Parr hybrid (B3LYP) functional was adopted to calculate exchange and correlation energy. An effective core potential basis set (ECP on core electrons and Dunning/Huzinaga on outer electrons) was found sufficiently accurate to reproduce experimental data. Clusters containing up to seven Pd atoms were considered and their interaction with hydrogen, methane and ethane and their fragments was analyzed and a kinetic study of the system was performed. Transition states structures and energies were calculated through quantum mechanics and kinetic constants were derived from a statistic thermodynamic approach. On the basis of such information, a kinetic model that accounts for ethane transformations. Finally the kinetic scheme was embedded in a plug flow reactor model and simulations were performed to test the validity of the developed mechanism. In this way information obtained at the atomic scale were adopted to study phenomena occurring on the much higher reactor scale.

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