Experimental and Numerical Characterization of a Novel Natural Gas Low NOx Burner in Gas Turbine Realistic Environment

2020 ◽  
Author(s):  
Matteo Cerutti ◽  
Pier Carlo Nassini ◽  
Daniele Pampaloni ◽  
Antonio Andreini
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
The Novel ◽  
Thermoacoustic Instability ◽  
Numerical Characterization ◽  
Annular Combustor ◽  
Development Phases ◽  
Reduced Scale

Abstract A fundamental milestone in the development of a low NOx burner technology is the demonstration of its capabilities in realistic environment. This is especially true for the novel burner subject of this paper, which has been extensively characterized throughout single burner scale experiments. The most promising geometry from the early development phases was selected for the assessment in realistic environment, consisting of a full-scale annular combustor test rig. This paper reports the main results of the assessment. Pollutant emissions and pressure pulsations have been measured at gas turbine relevant operating conditions. Moreover, dedicated blow-out tests have been performed to obtain the extinction equivalence ratio at both ambient and pressurized conditions, as done during the previous campaign. Basically, an adequate set of data has been gathered, allowing a direct comparison between full-annular and reduced-scale tests. A general alignment of behaviour has been observed, as both low NOx capability and blow-out characteristics of full-annular arrangement turned out to be substantially unchanged with respect to single burner. Nevertheless, some discrepancies in magnitude have been highlighted and discussed. Details have been given involving deeper numerical analysis by means of a dedicated model developed by the authors in previous works. Indeed, improvement to the model has been introduced in the context of this paper to overcome some limitations arisen in predicting emissions. Finally, a preliminary stability analysis has been carried out, with the aim to describe the onset of thermoacoustic instability tendency as observed in the full-annular tests.

Experimental and Numerical Characterization of a Novel Natural Gas Low NOx Burner in Gas Turbine Realistic Environment

2020 ◽  
Author(s):  
Matteo Cerutti ◽  
Pier Carlo Nassini ◽  
Daniele Pampaloni ◽  
Antonio Andreini
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
The Novel ◽  
Thermoacoustic Instability ◽  
Numerical Characterization ◽  
Annular Combustor ◽  
Development Phases ◽  
Reduced Scale

Abstract A fundamental milestone in the development of a low NOx burner technology is the demonstration of its capabilities in realistic environment. This is especially true for the novel burner subject of this paper, which has been extensively characterized throughout single burner scale experiments. An exhaustive description of the early development phases of the novel burner has been provided by authors in recently published works. The most promising geometry was selected for the assessment in real combustor arrangement, consisting of a full-scale annular combustor test rig. This paper reports the main results of such an assessment. Pollutant emissions and pressure pulsations have been measured at gas turbine relevant operating conditions. Moreover, dedicated blow-out tests have been performed to obtain the extinction equivalence ratio at both ambient and pressurized conditions, as done during the past single burner rig campaign. Basically, an adequate set of data has been gathered, allowing a direct comparison between full-annular and reduced-scale tests. A general alignment of behaviour has been observed, as both low NOx capability and blow-out characteristics of full-annular arrangement turned out to be substantially unchanged with respect to single burner. Nevertheless, some discrepancies in magnitude have been highlighted and discussed. Details have been given involving deeper numerical analysis by means of a dedicated model developed by the authors in previous works. Indeed, improvement to the model has been introduced in the context of this paper to overcome some limitations arisen in predicting emissions. Finally, a preliminary stability analysis has been carried out, with the aim to describe the onset of thermoacoustic instability tendency as observed in the full-annular tests.

Introduction of the Taurus™ 65 Industrial Gas Turbine for Power Generation

2008 ◽  
Author(s):  
George Rocha ◽  
Simon Reynolds ◽  
Theresa Brown
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Electrical Power ◽  
Field Evaluation ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Liquid Fuels ◽  
Operating Cycle ◽  
Product Experience ◽  
Exhaust Heat

Solar Turbines Incorporated has combined proven technology and product experience to develop the new Taurus 65 gas turbine for industrial power generation applications. The single-shaft engine is designed to produce 6.3 megawatts of electrical power with a 33% thermal efficiency at ISO operating conditions. Selection of the final engine operating cycle was based on extensive aerodynamic-cycle studies to achieve optimum output performance with increased exhaust heat capacity for combined heat and power installations. The basic engine configuration features an enhanced version of the robust Centaur®50 air compressor coupled to a newly designed three-stage turbine similar to the Taurus 70 turbine design. Advanced cooling technology and materials are used in the dry, lean-premix annular combustor, consistent with Solar’s proven SoLoNOx™ combustion technology, capable of reducing pollutant emissions while operating on standard natural gas or diesel liquid fuels. Like the Titan™ 130 and Taurus 70 products, a traditional design philosophy has been applied in development of the Taurus 65 gas turbine by utilizing existing components, common technology and product experience to minimize risk, lower cost and maximize durability. A comprehensive factory test plan and extended field evaluation program was used to validate the design integrity and demonstrate product durability prior to full market introduction.

Numerical Characterization of Flow and Heat Transfer in Pre-Swirl Systems

2017 ◽  
Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Jacopo D’Errico
Keyword(s):  
Heat Transfer ◽  
Gas Turbines ◽  
Numerical Study ◽  
Physical Phenomenon ◽  
Computational Procedure ◽  
Operating Conditions ◽  
Simulation Techniques ◽  
Numerical Characterization ◽  
Unsteady Simulation

This paper deals with a numerical study aimed at the validation of a computational procedure for the aerothermal characterization of pre-swirl systems employed in axial gas turbines. The numerical campaign focused on an experimental facility which models the flow field inside a direct-flow pre-swirl system. Steady and unsteady simulation techniques were adopted in conjunction with both a standard two-equations RANS/URANS modelling and more advanced approaches such as the Scale-Adaptive-Simulation principle, the SBES and LES. The comparisons between CFD and experiments were done in terms of swirl number development, static and total pressure distributions, receiving holes discharge coefficient and heat transfer on the rotor disc surface. Several operating conditions were accounted for, spanning 0.78·106<Reφ<1.21·106 and 0.123<λt<0.376. Overall the steady-state CFD predictions are in good agreement with the experimental evidences even though it is not able to confidently mimic the experimental swirl and pressure behaviour in some regions. Although the use of unsteady sliding mesh and direct turbulence modelling, would in principle increase the insight in the physical phenomenon, from a design perspective the tradeoff between accuracy and computational costs is not always favourable.

Wheel Box Test Aeromechanical Verification of New First Stage Bucket With Integrated Cover Plates for MS5002 GT

2019 ◽  
Author(s):  
Marco Mariottini ◽  
Nicola Pieroni ◽  
Pietro Bertini ◽  
Beniamino Pacifici ◽  
Alessandro Giorgetti
Keyword(s):  
Gas Turbine ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Response Assessment ◽  
Operating Conditions ◽  
Analytical Models ◽  
Gas Industry ◽  
Improved Performance ◽  
Cover Plates

Abstract In the oil and gas industry, manufacturers are continuously engaged in providing machines with improved performance, reliability and availability. First Stage Bucket is one of the most critical gas turbine components, bearing the brunt of very severe operating conditions in terms of high temperature and stresses; aeromechanic behavior is a key characteristic to be checked, to assure the absence of resonances that can lead to damage. Aim of this paper is to introduce a method for aeromechanical verification applied to the new First Stage Bucket for heavy duty MS5002 gas turbine with integrated cover plates. This target is achieved through a significantly cheaper and streamlined test (a rotating test bench facility, formally Wheel Box Test) in place of a full engine test. Scope of Wheel Box Test is the aeromechanical characterization for both Baseline and New bucket, in addition to the validation of the analytical models developed. Wheel Box Test is focused on the acquisition and visualization of dynamic data, simulating different forcing frequencies, and the measurement of natural frequencies, compared with the expected results. Moreover, a Finite Elements Model (FEM) tuning for frequency prediction is performed. Finally, the characterization of different types of dampers in terms of impact on frequencies and damping effect is carried out. Therefore, in line with response assessment and damping levels estimation, the most suitable damper is selected. The proposed approach could be extended for other machine models and for mechanical audits.

Towards Improved Boundary Layer Flashback Resistance of a 65 kW Gas Turbine With a Retrofittable Injector Concept

2018 ◽  
Author(s):  
Alireza Kalantari ◽  
Vincent McDonell ◽  
Scott Samuelsen ◽  
Shahram Farhangi ◽  
Don Ayers
Keyword(s):  
Boundary Layer ◽  
Gas Turbine ◽  
Elevated Pressure ◽  
Current Data ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Pollutant Emissions ◽  
Wall Region ◽  
Lean Premixed Combustion ◽  
High Hydrogen

Lean premixed combustion is extensively used in gas turbine industry to reduce pollutant emissions. However, combustion stability still remains as a primary challenge associated with high hydrogen content fuels. Flashback is a crucial concern for designing gas turbine combustors in terms of operability limits. The current experimental study addresses the boundary layer flashback of hydrogen-air premixed jet flames at gas turbine premixer conditions (i.e. elevated pressure and temperature). Flashback propensity of a commercially available injector, originally designed for natural gas, is studied at different operating conditions and corresponding measurements are presented. The pressure dependence of flashback propensity is consistent with previous studies. The previously developed flashback model is successfully applied to the current data, verifying its utilization for various test conditions/setups. In addition, the model is used to predict flashback propensity of the injector at the actual engine preheat temperature. The injector is then modified to increase boundary layer flashback resistance and the corresponding data are collected at the same operating conditions. To avoid the boundary layer flashback, the mixture is leaned out in the near-wall region, where the flame can potentially propagate upstream. The comparison of gathered data shows a clear improvement in flashback resistance. This improvement is further elaborated by numerically studying fuel/air mixing characteristics for the two injectors.

Modeling of Turbulent Combustion and Radiative Heat Transfer in a Object-Oriented CFD Code for Gas Turbine Application

2008 ◽  
Author(s):  
Antonio Andreini ◽  
Matteo Cerutti ◽  
Bruno Facchini ◽  
Luca Mangani
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Radiative Heat Transfer ◽  
Turbulent Combustion ◽  
Radiative Heat ◽  
Object Oriented ◽  
Flame Stabilization ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Combustion Models

One of the driving requirements in gas turbine design is the combustion analysis. The reduction of exhaust pollutant emissions is in fact the main design constraint of modern gas turbine engines, requiring a detailed investigation of flame stabilization criteria and temperature distribution within combustion chamber. At the same time, the prediction of thermal loads on liner walls continues to represent a critical issue especially with diffusion flame combustors which are still widely used in aeroengines. To meet such requirement, design techniques have to take advantage also of the most recent CFD tools that have to supply advanced combustion models according to the specific application demand. Even if LES approach represents a very accurate approach for the analysis of reactive flows, RANS computation still represents a fundamental tool in industrial gas turbine development, thanks to its optimal tradeoff between accuracy and computational costs. This paper describes the development and the validation of both combustion and radiation models in a object-oriented RANS CFD code: several turbulent combustion models were considered, all based on a generalized presumed PDF flamelet approach, valid for premixed and non premixed flames. Concerning radiative heat transfer calculations, two directional models based on the P1-Approximation and the Finite Volume Method were treated. Accuracy and reliability of developed models have been proved by performing several computations on well known literature test-cases. Selected cases investigate several turbulent flame types and regimes allowing to prove code affordability in a wide range of possible gas turbine operating conditions.

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.

Investigation of Flame Stabilization in a High-Pressure Multi-Jet Combustor by Laser Measurement Techniques

2014 ◽  
Author(s):  
Oliver Lammel ◽  
Tim Rödiger ◽  
Michael Stöhr ◽  
Holger Ax ◽  
Peter Kutne ◽  
...  
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Recirculation Zone ◽  
Flame Stabilization ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Single Shot ◽  
Optical Access

In this contribution, comprehensive optical and laser based measurements in a generic multi-jet combustor at gas turbine relevant conditions are presented. The flame position and shape, flow field, temperatures and species concentrations of turbulent premixed natural gas and hydrogen flames were investigated in a high-pressure test rig with optical access. The needs of modern highly efficient gas turbine combustion systems, i.e., fuel flexibility, load flexibility with increased part load capability, and high turbine inlet temperatures, have to be addressed by novel or improved burner concepts. One promising design is the enhanced FLOX® burner, which can achieve low pollutant emissions in a very wide range of operating conditions. In principle, this kind of gas turbine combustor consists of several nozzles without swirl, which discharge axial high momentum jets through orifices arranged on a circle. The geometry provides a pronounced inner recirculation zone in the combustion chamber. Flame stabilization takes place in a shear layer around the jet flow, where fresh gas is mixed with hot exhaust gas. Flashback resistance is obtained through the absence of low velocity zones, which favors this concept for multi-fuel applications, e.g. fuels with medium to high hydrogen content. The understanding of flame stabilization mechanisms of jet flames for different fuels is the key to identify and control the main parameters in the design process of combustors based on an enhanced FLOX® burner concept. Both experimental analysis and numerical simulations can contribute and complement each other in this task. They need a detailed and relevant data base, with well-known boundary conditions. For this purpose, a high-pressure burner assembly was designed with a generic 3-nozzle combustor in a rectangular combustion chamber with optical access. The nozzles are linearly arranged in z direction to allow for jet-jet interaction of the middle jet. This line is off-centered in y direction to develop a distinct recirculation zone. This arrangement approximates a sector of a full FLOX® gas turbine burner. The experiments were conducted at a pressure of 8 bar with preheated and premixed natural gas/air and hydrogen/air flows and jet velocities of 120 m/s. For the visualization of the flame, OH* chemiluminescence imaging was performed. 1D laser Raman scattering was applied and evaluated on an average and single shot basis in order to simultaneously and quantitatively determine the major species concentrations, the mixture fraction and the temperature. Flow velocities were measured using particle image velocimetry at different section planes through the combustion chamber.

Development of a Liquid-Fueled, Lean-Premixed Gas Turbine Combustor

1993 ◽  
Vol 115 (3) ◽  
pp. 554-562 ◽  
Author(s):  
L. H. Cowell ◽  
K. O. Smith
Keyword(s):  
Gas Turbine ◽  
Performance Testing ◽  
Operating Conditions ◽  
Operating Parameters ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Design Variables ◽  
Lean Premixed ◽  
Annular Combustor ◽  
Injector Design

Development of a lean-premixed, liquid-fueled combustor is in progress to achieve ultra-low NOx emissions at typical gas turbine operating conditions. A filming fuel injector design was tested on a bench scale can combustor to evaluate critical design and operating parameters for low-emissions performance. Testing was completed using No. 2 diesel. Key design variables tested include premixing length, swirler angle, injector centerbody diameter, and reduced liner cooling. NOx emissions below 12 ppmv at 9 bar pressure were measured. Corresponding CO levels were 50 ppmv. An optimized injector design was fabricated for testing in a three injector sector of an annular combustor. Operating parameters and test results are discussed in the paper.

Boundary Layer Flashback Prediction for Turbulent Premixed Jet Flames: Comparison of Two Models

2019 ◽  
Author(s):  
Alireza Kalantari ◽  
Nicolas Auwaijan ◽  
Vincent McDonell
Keyword(s):  
Boundary Layer ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Turbulent Flame ◽  
Flame Speed ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Jet Flames ◽  
Turbulent Flame Speed ◽  
Turbulent Premixed

Abstract Lean-premixed combustion is commonly used in gas turbines to achieve low pollutant emissions, in particular nitrogen oxides. But use of hydrogen-rich fuels in premixed systems can potentially lead to flashback. Adding significant amounts of hydrogen to fuel mixtures substantially impacts the operating range of the combustor. Hence, to incorporate high hydrogen content fuels into gas turbine power generation systems, flashback limits need to be determined at relevant conditions. The present work compares two boundary layer flashback prediction methods developed for turbulent premixed jet flames. The Damköhler model was developed at University of California Irvine (UCI) and evaluated against flashback data from literature including actual engines. The second model was developed at Paul Scherrer Institut (PSI) using data obtained at gas turbine premixer conditions and is based on turbulent flame speed. Despite different overall approaches used, both models characterize flashback in terms of similar parameters. The Damköhler model takes into account the effect of thermal coupling and predicts flashback limits within a reasonable range. But the turbulent flame speed model provides a good agreement for a cooled burner, but shows less agreement for uncooled burner conditions. The impact of hydrogen addition (0 to 100% by volume) to methane or carbon monoxide is also investigated at different operating conditions and flashback prediction trends are consistent with the existing data at atmospheric pressure.

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