Parametric Simulation of Turbulent Reacting Flow and Emissions in a Lean Premixed Reverse Flow Type Gas Turbine Combustor

2011 ◽  
Vol 134 (2) ◽  
Author(s):  
Daero Joung ◽  
Kang Y. Huh ◽  
Yunho An
Keyword(s):  
Temperature Distribution ◽  
Gas Turbine ◽  
Reverse Flow ◽  
Physical Models ◽  
Pollutant Emissions ◽  
Reacting Flow ◽  
Outlet Temperature ◽  
Operating Pressure ◽  
Gas Turbine Combustor ◽  
Fuel Ratio

This paper describes simulation of a small stationary gas turbine combustor of a reverse flow, semi-silo type for power generation. The premixed coherent flame model (PCFM) is applied for partially premixed methane/air with an imposed downstream flame area density (FAD) to avoid flashback and incomplete combustion. Physical models are validated against the measurements of outlet temperature, product gas composition, and NO emission at the low operating pressure. Parametric study is performed to investigate the effect of load and pilot/total (P/T) fuel ratio on mixing characteristics and the resulting temperature distribution and pollutant emissions. As the P/T fuel ratio increases, the high temperature region over 1900 K enhances reaction of the mixture from the main nozzle in the primary mixing zone. For low P/T ratios, the pilot stream dilutes the mixture, on the contrary, to suppress reaction with an increasing height of the lifted flame. The NO is associated with the unmixedness as well as the mean temperature level and tends to increase with increasing load and P/T ratio. The high operating pressure does not affect overall velocity and temperature distribution, while it tends to increase NO and liner temperature under the given boundary conditions.

3D RANS Simulation of Turbulent Flow and Combustion in a 5 MW Reverse-Flow Type Gas Turbine Combustor

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
Daero Joung ◽  
Kang Y. Huh
Keyword(s):  
Turbulent Flow ◽  
Gas Turbine ◽  
Reverse Flow ◽  
Measurement Data ◽  
Swirl Flow ◽  
Reacting Flow ◽  
Mean Flow ◽  
Gas Turbine Combustor ◽  
Rans Simulation ◽  
Combustion Models

This study is concerned with 3D RANS simulation of turbulent flow and combustion in a 5 MW commercial gas turbine combustor. The combustor under consideration is a reverse flow, dry low NOx type, in which methane and air are partially mixed inside swirl vanes. We evaluated different turbulent combustion models to provide insights into mixing, temperature distribution, and emission in the combustor. Validation is performed for the models in STAR-CCM+ against the measurement data for a simple swirl flame (http://public.ca.sandia.gov/TNF/swirlflames.html). The standard k-ε model with enhanced wall treatment is employed to model turbulent swirl flow, whereas eddy break-up (EBU), presumed probability density function laminar flamelet model, and partially premixed coherent flame model (PCFM) are tried for reacting flow in the combustor. Independent simulations are carried out for the main and pilot nozzles to avoid flashback and to provide realistic inflow boundary conditions for the combustor. Geometrical details such as air swirlers, vane passages, and liner holes are all taken into account. Tested combustion models show similar downstream distributions of the mean flow and temperature, while EBU and PCFM show a lifted flame with stronger effects of swirl due to limited increase in axial momentum by expansion.

The Effects of Pressure on Gas Turbine Combustor Performance: An Investigation via Numerical Simulation

2006 ◽  
Author(s):  
Yufeng Cui ◽  
Gang Xu ◽  
Bin Yu ◽  
Chaoqun Nie ◽  
Weiguang Huang
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
Radiation Heat Transfer ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Operating Pressure ◽  
Gas Turbine Combustor ◽  
Flamelet Model ◽  
Air Inlet ◽  
Operation Pressure

Performance tests of a gas turbine combustor are usually conducted at atmospheric or medium pressure which is quite different from its real operating condition. The effects of pressure on the performance of a gas turbine combustor for burning medium-heating-value syngas are researched by numerical simulation in this paper. The geometry of the combustor is modeled by coupling all its components including nozzle, combustor liner and sealant tube. In the simulation a laminar flamelet model and P-1 radiation model are adopted. The numerical results show that at the same fuel and air inlet temperature and the same equivalence ratio, the operation pressure has less effect on the flow fields, but its effect on the temperature distribution is obvious. Both the highest temperature in the combustor and the outlet temperature increase with increasing operating pressure because of the weakening of the dissociation of the H2O, CO2 and so on. Moreover, as pressure increases, the concentration of H2O and CO2 in the combustor increase, and so to does the absorption coefficient and the emissivity of gas inside the liner. As a result, the radiation heat transfer between the gas and the combustion liner wall is enhanced, and the wall temperature of the liner increases. The NOx emissions of the combustor are also distinctly higher at high pressure than at low pressure.

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.

Towards Improved Prediction of Aero-Engine Combustor Performance Using Large Eddy Simulations

2008 ◽  
Author(s):  
S. James ◽  
M. S. Anand ◽  
B. Sekar
Keyword(s):  
Gas Turbine ◽  
Radial Profile ◽  
Design Tool ◽  
Operating Conditions ◽  
Outlet Temperature ◽  
Gas Turbine Combustor ◽  
Systematic Assessment ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Aero Engine

The paper presents an assessment of large eddy simulation (LES) and conventional Reynolds averaged methods (RANS) for predicting aero-engine gas turbine combustor performance. The performance characteristic that is examined in detail is the radial burner outlet temperature (BOT) or fuel-air ratio profile. Several different combustor configurations, with variations in airflows, geometries, hole patterns and operating conditions are analyzed with both LES and RANS methods. It is seen that LES consistently produces a better match to radial profile as compared to RANS. To assess the predictive capability of LES as a design tool, pretest predictions of radial profile for a combustor configuration are also presented. Overall, the work presented indicates that LES is a more accurate tool and can be used with confidence to guide combustor design. This work is the first systematic assessment of LES versus RANS on industry-relevant aero-engine gas turbine combustors.

Acoustic Control of Dilution-Air Mixing in a Gas Turbine Combustor

1982 ◽  
Author(s):  
P. J. Vermeulen ◽  
J. Odgers ◽  
V. Ramesh
Keyword(s):  
Temperature Distribution ◽  
Temperature Profile ◽  
Gas Turbine ◽  
Exit Plane ◽  
Gas Turbine Combustor ◽  
Acoustic Control ◽  
Air Mixing ◽  
Air Flows ◽  
Plane Temperature ◽  
Load Conditions

A small combustor of normal design employing acoustic control of the dilution-air flows has been successfully tested up to “half-load” conditions. It has been shown that this technique can be used to selectively and progressively control the exit plane temperature distribution, and the ability to trim the temperature profile has been convincingly demonstrated. The acoustic driver power requirements were minimal indicating that driver power at “full-load” will not be excessive. The nature of the acoustically modulated dilution-air flows has been clearly establish to the design of combustors such that a desired exit plane temperature distribution may be achieved.

Kinetics Modeling on NOx Emissions of a Syngas Turbine Combustor Using RQL Combustion Method

2019 ◽  
Author(s):  
Haoyang Liu ◽  
Wenkai Qian ◽  
Min Zhu ◽  
Suhui Li
Keyword(s):  
Gas Turbine ◽  
Residence Time ◽  
Air Flow ◽  
Nox Reduction ◽  
Outlet Temperature ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Kinetics Modeling ◽  
The Rich ◽  
Nox Control

Abstract To avoid flashback issues of the high-H2 syngas fuel, current syngas turbines usually use non-premixed combustors, which have high NOx emissions. A promising solution to this dilemma is RQL (rich-burn, quick-mix, lean-burn) combustion, which not only reduces NOx emissions, but also mitigates flashback. This paper presents a kinetics modeling study on NOx emissions of a syngas-fueled gas turbine combustor using RQL architecture. The combustor was simulated with a chemical reactor network model in CHEMKIN-PRO software. The combustion and NOx formation reactions were modeled using a detailed kinetics mechanism that was developed for syngas. Impacts of combustor design/operating parameters on NOx emissions were systematically investigated, including combustor outlet temperature, rich/lean air flow split and residence time split. The mixing effects in both the rich-burn zone and the quick-mix zone were also investigated. Results show that for an RQL combustor, the NOx emissions initially decrease and then increase with combustor outlet temperature. The leading parameters for NOx control are temperature-dependent. At typical modern gas turbine combustor operating temperatures (e.g., < 1890 K), the air flow split is the most effective parameter for NOx control, followed by the mixing at the rich-burn zone. However, as the combustor outlet temperature increases, the impacts of air flow split and mixing in the rich-burn zone on NOx reduction become less pronounced, whereas both the residence time split and the mixing in the quick-mix zone become important.

Bioethanol Combustion in an Industrial Gas Turbine Combustor: Simulations and Experiments

2014 ◽  
Vol 136 (7) ◽  
Author(s):  
Joost L. H. P. Sallevelt ◽  
Artur K. Pozarlik ◽  
Martin Beran ◽  
Lars-Uno Axelsson ◽  
Gerrit Brem
Keyword(s):  
Gas Turbine ◽  
Model Comparison ◽  
Reverse Flow ◽  
Operating Conditions ◽  
Fuel Spray ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Gas Turbine Combustor ◽  
Diffusion Type ◽  
Flamelet Model

Combustion tests with bioethanol and diesel as a reference have been performed in OPRA's 2 MWe class OP16 gas turbine combustor. The main purposes of this work are to investigate the combustion quality of ethanol with respect to diesel and to validate the developed CFD model for ethanol spray combustion. The experimental investigation has been conducted in a modified OP16 gas turbine combustor, which is a reverse-flow tubular combustor of the diffusion type. Bioethanol and diesel burning experiments have been performed at atmospheric pressure with a thermal input ranging from 29 to 59 kW. Exhaust gas temperature and emissions (CO, CO2, O2, NOx) were measured at various fuel flow rates while keeping the air flow rate and air temperature constant. In addition, the temperature profile of the combustor liner has been determined by applying thermochromic paint. CFD simulations have been performed with ethanol for five different operating conditions using ANSYS FLUENT. The simulations are based on a 3D RANS code. Fuel droplets representing the fuel spray are tracked throughout the domain while they interact with the gas phase. A liner temperature measurement has been used to account for heat transfer through the flame tube wall. Detailed combustion chemistry is included by using the steady laminar flamelet model. Comparison between diesel and bioethanol burning tests show similar CO emissions, but NOx concentrations are lower for bioethanol. The CFD results for CO2 and O2 are in good agreement, proving the overall integrity of the model. NOx concentrations were found to be in fair agreement, but the model failed to predict CO levels in the exhaust gas. Simulations of the fuel spray suggest that some liner wetting might have occurred. However, this finding could not be clearly confirmed by the test data.

Preliminary CFD Investigation of Syngas Combustion at Different Operating Pressures

2015 ◽  
Vol 786 ◽  
pp. 215-219
Author(s):  
Norhaslina Mat Zian ◽  
Hasril Hasini ◽  
Nur Irmawati Om
Keyword(s):  
Temperature Distribution ◽  
Thermal Power ◽  
Combustion Process ◽  
Pressure Variation ◽  
Operating Pressure ◽  
Gas Turbine Combustor ◽  
Average Temperature ◽  
Conventional Combustion ◽  
Synthetic Gas ◽  
Syngas Combustion

Study on the flow and combustion behavior inside gas turbine combustor used in thermal power plant is described in this paper. The combustion process takes place using synthetic gas and emphasis is given to the effect of pressure variation on flame profile, temperature distribution and emissions as compared to the conventional combustion using methane. The operating pressure of the can-type combustor varies in the range of 1-10 atm. while the syngas composition is assumed to have fixed values of 10% CH4, 55% CO, 30% H2 and 5% N2. Preliminary result shows that the flow inside the can-combustor is highly swirling which indicates good mixing of fuel and air prior to the entrance of the mixture to the main combustion zone. The temperature distribution at combustor mid plane show identical pattern for pressure range between 1-10 atm for both maximum and average temperature magnitude.

Sign in / Sign up

Export Citation Format

Share Document