Experimental Investigation of the Combustion Behavior of Single-Nozzle Liquid-Flox®-Based Burners on an Atmospheric Test Rig

2020 ◽  
Author(s):  
Saeed Izadi ◽  
Jan Zanger ◽  
Oliver Kislat ◽  
Benedict Enderle ◽  
Felix Grimm ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Gas Turbines ◽  
Liquid Fuel ◽  
Gas Flow ◽  
Thermal Power ◽  
Cross Flow ◽  
Flame Length ◽  
Design Parameters ◽  
Gaseous Fuels ◽  
Lift Off

Abstract As an alternative to the commonly used swirl burners in micro gas turbines (MGT), the FLOX®-based combustion concept promises great potential for the nitric oxide emission reduction and increased fuel flexibility. Previous research on FLOX®-based MGT combustors mainly addressed gaseous fuels and there is less experience available on liquid fuel FLOX®-based MGT combustors. A FLOX®-based liquid fuel burner is developed to fit into a newly designed combustor for the Capstone C30 MGT. The studied FLOX®-based burners consist of an air nozzle with a coaxially arranged fuel pressure atomizer. The combustion chamber walls are made of quartz glass to enable optical accessibility for analyzing the structural properties of the flame. Furthermore, a diagonal hot cross-flow is arranged to emulate the annular hot gas flow of the other two burners in the MGT. The cross-flow is realized by utilizing a 20-nozzle FLOX®-based natural gas combustor. Measurements include visualization of the reaction zone and analysis of the exhaust gas emissions. By detecting the hydroxyl radical chemiluminescence (OH*-CL) emissions, the position of the heat release zone within the combustion chamber is attained. Correspondingly, the flame lift-off height and flame length are calculated. The investigated design parameters include air preheat temperature up to 733 K, equivalence ratio, burner geometry, and thermal power. The work presented in this paper aims to deepen the understanding of the design parameter interactions involved within the single-nozzle liquid-FLOX®-based burners.

Experimental Investigation of the Combustion Behavior of Single-Nozzle Liquid-FLOX®-Based Burners on an Atmospheric Test Rig

2020 ◽  
Author(s):  
Saeed Izadi ◽  
Jan Zanger ◽  
Oliver Kislat ◽  
Benedict Enderle ◽  
Felix Grimm ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Gas Turbines ◽  
Liquid Fuel ◽  
Thermal Power ◽  
Cross Flow ◽  
Exhaust Gas ◽  
Gas Emissions ◽  
The Cross ◽  
Exhaust Gas Emissions ◽  
Medium Diameter

Abstract As an alternative to the commonly used swirl burners in micro gas turbines (MGT), the FLOX®-based combustion concept promises great potential for the nitric oxide emission reduction and increased fuel flexibility. Previous research on FLOX®-based MGT combustors mainly addressed gaseous fuels and there is limited knowledge available on liquid fuel FLOX®-based MGT combustors. Despite having to deal with a new set of challenges while utilizing liquid fuel in the burner, first steps are taken to gain more information on the influencing operational parameters. In this regard, a FLOX®-based liquid fuel burner is developed to fit into a newly designed combustor for the Capstone C30 MGT. The C30 combustor operates with three burners arranged tangentially to an annular combustion chamber and provides a total thermal power of 115 kW. In this work, operational properties of merely one of the three C30 liquid fuel burners are investigated and the rest of the two burners are emulated in form of hot cross–flow. As for the liquid burners, the experiments are conducted with three geometrically different single–nozzle burners at atmospheric pressure. The studied FLOX®-based burners consist of an air nozzle with a coaxially arranged fuel pressure atomizer. The cross–flow is realized by utilizing a 20–nozzle FLOX®-based natural gas combustor. Measurements include visualization of the reaction zone and analysis of the exhaust gas emissions. By detecting the hydroxyl radical chemiluminescence (OH*-CL) emissions, the position of the heat release zone within the combustion chamber is attained. Correspondingly, the flame height above burner and the flame length are calculated. The investigated design parameters include air preheat temperature up to 733 K, equivalence ratio, burner geometry, and thermal power. The work presented in this paper aims to deepen the understanding of the design parameter interactions involved within the single–nozzle liquid–FLOX®-based burners. The cross–flow is set at a constant operating point to take the influence of the circulating hot gases on the flame into account. Through variation of thermal power the effect of liquid fuel preparation, i.e., atomization, evaporation, and mixing on combustion properties and exhaust gas emissions are examined. Analyses of measurements of different burner configurations are shown. The results show that the burners with the medium diameter consistently performed remarkably at different flame temperatures and thermal powers. The lowest NOx and CO emissions for the medium diameter burner lied between 5–7 ppm and 8–10 ppm, respectively. The collected data sets can be used for the validation of numerical simulations as well.

Development of a Liquid Fuel Combustion System for SGT-750

2014 ◽  
Author(s):  
Olle Lindman ◽  
Mats Andersson ◽  
Magnus Persson ◽  
Erik Munktell
Keyword(s):  
Gas Turbines ◽  
Liquid Fuel ◽  
Cross Flow ◽  
Development Program ◽  
Medium Size ◽  
Combustion System ◽  
Gaseous Fuels ◽  
Air Mixing ◽  
Industrial Gas Turbines ◽  
Fuel Nozzle

This paper describes the latest results from the development of a liquid fuel solution for the 4th generation DLE system for Siemens medium size gas turbines. Gaseous fuels are the dominating fuels for industrial gas turbines. However, many customers need to be able to run on liquid fuel as backup. The demand for dry low NOx emissions when operating on liquid fuel is increasing. The aim for the 4th generation DLE system incorporated in the recently released SGT-750 [1] is to have emission levels well below market demands on both gas and liquid fuel. This paper will highlight the technical challenges when adding liquid fuel operation to a combustion system optimized for gas operation. The stand-alone spray characteristics for a liquid fuel nozzle is quite easy to predict, but the final combustion performance in a hot air cross flow environment is all but easy to predict by numerical simulations or cold flow tests [2]. Due to the complexity of the challenge, the development program focused on a selection of concepts for which fuel/air mixing calculations were made. The investigation was completed by testing in a full scale, single burner high pressure combustion test rig.

Development and Integration of the Dual Fuel Combustion System for the MGT Gas Turbine Family

2021 ◽  
Author(s):  
Bernhard Ćosić ◽  
Frank Reiss ◽  
Marc Blümer ◽  
Christian Frekers ◽  
Franklin Genin ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Distribution System ◽  
Gas Turbines ◽  
Liquid Fuel ◽  
Fuel Injection ◽  
Liquid Fuels ◽  
Dual Fuel ◽  
Gaseous Fuels ◽  
Supply And Distribution ◽  
Industrial Gas Turbines

Abstract Industrial gas turbines like the MGT6000 are often operated as power supply or as mechanical drives. In these applications, liquid fuels like 'Diesel Fuel No.2' can be used either as main fuel or as backup fuel if natural gas is not reliably available. The MAN Gas Turbines (MGT) operate with the Advanced Can Combustion (ACC) system, which is capable of ultra-low NOx emissions for gaseous fuels. This system has been further developed to provide dry dual fuel capability. In the present paper, we describe the design and detailed experimental validation process of the liquid fuel injection, and its integration into the gas turbine package. A central lance with an integrated two-stage nozzle is employed as a liquid pilot stage, enabling ignition and start-up of the engine on liquid fuel only. The pilot stage is continuously operated, whereas the bulk of the liquid fuel is injected through the premixed combustor stage. The premixed stage comprises a set of four decentralized nozzles based on fluidic oscillator atomizers, wherein atomization of the liquid fuel is achieved through self-induced oscillations. We present results illustrating the spray, hydrodynamic, and emission performance of the injectors. Extensive testing of the burner at atmospheric and full load high-pressure conditions has been performed, before verification within full engine tests. We show the design of the fuel supply and distribution system. Finally, we discuss the integration of the dual fuel system into the standard gas turbine package of the MGT6000.

Measurement and Abatement of PM Emitted by Stationary Gas Turbines: Experience Gained With Different Fuels and Combustor Types

2018 ◽  
Author(s):  
Aristotelis Komodromos ◽  
George Moniatis ◽  
Frixos Kontopoulos ◽  
George Zaimis ◽  
Matthieu Vierling ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Liquid Fuel ◽  
Power Plants ◽  
Water Injection ◽  
Liquid Fuels ◽  
Injection System ◽  
Joint Work ◽  
Gaseous Fuels ◽  
Scale Test ◽  
Combustion Systems

Whichever the type of combustion installation, liquid fuels burned in gas turbines tend to generate particulate matter (PM) emissions, which consist in soot only or in ash plus soot, according to their ash-free or ash-forming character. Standard diffusion flame combustion systems are known as “universal” combustors, capable to burn both ash-free (naphtha, light and heavy distillates) and ash-forming (crude and heavy) fuels. In contrast, DLN systems are designed to burn gaseous fuels and light distillates. PMs in the range of a few parts per million represent a solid micropollutant, the measurement and abatement of which creates specific technical challenges. In order to fully characterize soot emission and investigate their reduction, GE has undertaken a multi-year investigation program covering (i) an exploratory engineering study starting from the EN13284-1 standard and (ii) the testing of a number of inorganic oxidation catalysts used in the form of fuel additives (“soot inhibitors”). In this framework, a joint work involving GE and Electricity Authority of Cyprus has been conducted in the first half of 2017 and a full-scale test plan has been performed at the Vasilikos power plant in Cyprus, involving a Frame 6F.03 DLN2.6 that burns light distillate oil and is equipped with a DeNOx water injection system. Four types of soot inhibitor additives: cerium (IV) and (III), iron (III) and (II) were tested. This paper reviews the results of this field test and compares them with data previously acquired at other power plants featuring different liquid fuels and combustion systems. Its goal is to provide the gas turbine community with a better understanding of PM emissions and their abatement using various soot inhibitor candidates, in function of liquid fuel type and combustion system.

A Model for Predicting the Lift-Off Height of Premixed Jets in Vitiated Cross Flow

2015 ◽  
Author(s):  
Michael Kolb ◽  
Denise Ahrens ◽  
Christoph Hirsch ◽  
Thomas Sattelmayer
Keyword(s):  
Time Scale ◽  
Ignition Delay ◽  
Gas Turbines ◽  
Cross Flow ◽  
Flame Stabilization ◽  
Staged Combustion ◽  
Flow Temperature ◽  
Jet Flame ◽  
Stage Combustion ◽  
Lift Off

Lean premixed single-stage combustion is state of the art for low pollution combustion in heavy-duty gas turbines with gaseous fuels. The application of premixed jets in multi-stage combustion to lower nitric oxide emissions and enhance turndown ratio is a novel promising approach. At the Lehrstuhl für Thermodynamik, Technische Universität München, a large scale atmospheric combustion test rig has been set up for studying staged combustion. The understanding of lift-off behavior is crucial for determining the amount of mixing before ignition and for avoiding flames anchoring at the combustor walls. This experiment studies jet lift-off depending on jet equivalence ratio (0.58–0.82), jet preheat temperature (288–673 K), cross flow temperature (1634–1821 K) and jet momentum ratio (6–210). The differences to existing lift-off studies are the high cross flow temperature and applying a premixed jet. The lift-off height of the jet flame is determined by OH* chemiluminescence images, and subsequently, the data is used to analyze the influence of each parameter and to develop a model that predicts the lift-off height for similar staged combustion systems. A main outcome of this work is that the lift-off height in a high temperature cross flow cannot be described by one dimensionless number like Damköhler- or Karlovitz number. Furthermore, the ignition delay time scale τign also misses part of the lift-off height mechanism. The presented model uses turbulent time scales, the ignition delay and a chemical time scale based on the laminar flame speed. An analysis of the model reveals flame stabilization mechanisms and explains the importance of different time scale.

Application of Planar Laser-Induced Phosphorescence to Investigate Jet-A Injection Into a Cross-Flow of Hot Air

2014 ◽  
Author(s):  
Zu Puayen Tan ◽  
Eugene Lubarsky ◽  
Oleksandr Bibik ◽  
Dmitriy Shcherbik ◽  
Ben T. Zinn
Keyword(s):  
Gas Turbines ◽  
Liquid Fuel ◽  
Laser Sheet ◽  
Cross Flow ◽  
Mie Scattering ◽  
Fuel Concentration ◽  
Spectral Bands ◽  
Jet In Cross Flow ◽  
Thermographic Phosphor ◽  
Planar Laser

This paper describes the development of the Planar Laser-Induced Phosphorescence (PLIP) technique for mapping the fuel temperature and concentration distributions in a jet-in-cross-flow (JICF) spray study. The spray was produced by injecting cold liquid Jet-A into hot cross-flowing air. The application of PLIP required the seeding of liquid fuel with micron-size thermographic phosphor particles before injection. The resulting spray produced phosphorescence and droplets Mie-scattering signals when illuminated by a 355nm planar UV laser sheet of 0.054J/pulse energy. The technique was investigated as a potential alternative to the use of Jet-A Planar Laser-Induced Fluorescence (PLIF) for the mapping of fuel concentration in sprays, because the low signal intensity of Jet-A’s fluorescence at high T prevents the use of the PLIF approach. In contrast, PLIP provides a strong signal at high T, and allows the simultaneous determination of local T and fuel concentration when two spectral bands of the phosphorescence emission are imaged and their ratio-of-intensities (RI) determined. In addition, the locations where liquid fuel droplets exist were imaged from the UV Mie-scattering of the laser-sheet (which can also be done in PLIF). In the present investigation, an optical system that imaged two spectral bands of phosphorescence and one wavelength of Mie-scattering was developed. It consisted of three CCD cameras with dichroic beam-splitters and interference narrow bandpass filters. The spray-pattern within a span of ∼80×30 orifice diameters was captured, with spatial resolution of about 0.1mm/px. The investigated jet-in-cross-flow spray was produced by injecting Jet-A fuel from a 0.671mm diameter orifice located on the wall of a rectangular channel (25.4×31.75mm cross-section). The cross-flow air was preheated to temperatures encountered in modern gas turbines (up to 480°C), while the temperature of the injected Jet-A fuel was in the T = 27–80°C range. YVO4:Eu phosphor particles with a median size of 1.8 microns were used to seed the fuel. Since the emissions of the commonly used Dy:YAG thermographic phosphor were found to be too weak and had wavelengths that overlapped with Jet-A fluorescence signals, YVO4:Eu was used for the JICF studies instead. It was observed that while the emissions of YVO4:Eu were stronger than Dy:YAG, the range of T where it can be applied in the PLIP technique was more limited — just sufficient for the investigated JICF. Preliminary results from the study showed rapid changes in fuel concentration and T from the injector up to z/dinj∼30 for momentum ratios of J = 5, 10 and 20, followed by a more gradual mixing/heat-up downstream. It was also found that deposition of phosphor particles on channel-walls interfered with the spray characterization, reducing the accuracy of the measurements.

Numerical Analysis of Biomass-Derived Gaseous Fuels Fired in a RQL Micro Gas Turbine Combustion Chamber: Preliminary Results

2011 ◽  
Author(s):  
Paolo Laranci ◽  
Edoardo Bursi ◽  
Francesco Fantozzi
Keyword(s):  
Power Generation ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Carbon Dioxide Emissions ◽  
Gas Turbines ◽  
Landfill Gas ◽  
Pyrolysis Gas ◽  
Micro Gas Turbine ◽  
Gaseous Fuels ◽  
Reduce Carbon Dioxide

The economically sustainable availability of biomass residuals and the growing need to reduce carbon dioxide emissions from power generation facilities has driven the development of a series of processes that lead to the production of a variety of biomass-derived fuels gaseous fuels, such as syngas, pyrolysis gas, landfill gas and digester gas. These technologies can find an ideal coupling when used for fuelling micro gas turbines, especially for distributed power generation applications, in a range between 50 and 500 kWE. This paper features a report on numerical activity carried out at the University of Perugia on a 80 kWE micro gas turbine annular combustion chamber, featuring RQL technology, that has been numerically modeled in order to verify combustion requirements, principally in terms of air/fuel ratio and lower heating value, simulating mixtures with varying chemical composition. The use of CFD turbulence and combustion modeling, via both Eddy Break-up and non-adiabatic PPDF methods, allows us to evaluate flame temperatures and stability, NOx and unburnt hydrocarbons emissions, under various load conditions, for the different fuel mixtures taken into account.

Automated Design Space Exploration of Advanced-Shaped Film Cooling Holes Using the SHERPA Algorithm

2016 ◽  
Author(s):  
Karsten Kusterer ◽  
Jens Dickhoff ◽  
Noël T. Campana ◽  
Takao Sugimoto ◽  
Ryozo Tanaka ◽  
...  
Keyword(s):  
Film Cooling ◽  
Gas Turbines ◽  
Design Space Exploration ◽  
Design Space ◽  
Cross Flow ◽  
Design Parameters ◽  
Test Case ◽  
Lateral Direction ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness

In modern gas turbines, the film cooling technology is essential for the protection of hot parts. Today, shaped holes are widely used, but besides others, the NEKOMIMI-shaped cooling holes have shown that there is still potential to increase the film cooling effectiveness significantly by generation of Anti-Counter-Rotating Vortices (ACRV). As a result, the cooling air remains close to the wall and spreads in lateral direction along the surface. The ACRV result from the specialized shape of the expanding hole exits (NEKOMIMI-shape). Thus, the design parameters have a crucial impact to the film cooling effectiveness behind the hole. In the present study the design parameters are varied and in order to explore the design space for a defined test case with respect to the maximum achievable averaged adiabatic film cooling effectiveness. This illustrates the capabilities of the technology. Additionally, the design space of a laidback fan-shaped film cooling configuration is explored and compared to the result obtained with the NEKOMIMI-shaped geometry. In order to show the robustness of the configurations with respect to compound angles of the cross flow, two advanced configurations — one NEKOMIMI and one shaped hole — are analysed with compound angles up to 16°.

A Model for Predicting the Lift-Off Height of Premixed Jets in Vitiated Cross Flow

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Michael Kolb ◽  
Denise Ahrens ◽  
Christoph Hirsch ◽  
Thomas Sattelmayer
Keyword(s):  
Time Scale ◽  
Ignition Delay ◽  
Gas Turbines ◽  
Cross Flow ◽  
Flame Stabilization ◽  
Dimensionless Number ◽  
Staged Combustion ◽  
Flow Temperature ◽  
Jet Flame ◽  
Lift Off

Lean premixed single-stage combustion is state of the art for low pollution combustion in heavy-duty gas turbines with gaseous fuels. The application of premixed jets in multistage combustion to lower nitric oxide emissions and enhance turn-down ratio is a novel promising approach. At the Lehrstuhl für Thermodynamik, Technische Universität München, a large-scale atmospheric combustion test rig has been set up for studying staged combustion. The understanding of lift-off (LO) behavior is crucial for determining the amount of mixing before ignition and for avoiding flames anchoring at the combustor walls. This experiment studies jet LO depending on jet equivalence ratio (0.58–0.82), jet preheat temperature (288–673 K), cross flow temperature (1634–1821 K), and jet momentum ratio (6–210). The differences to existing LO studies are the high cross flow temperature and applying a premixed jet. The LO height of the jet flame is determined by OH* chemiluminescence images, and subsequently, the data is used to analyze the influence of each parameter and to develop a model that predicts the LO height for similar staged combustion systems. A main outcome of this work is that the LO height in a high temperature cross flow cannot be described by one dimensionless number like Damköhler- or Karlovitz-number. Furthermore, the ignition delay time scale τign also misses part of the LO height mechanism. The presented model uses turbulent time scales, the ignition delay, and a chemical time scale based on the laminar flame speed. An analysis of the model reveals flame stabilization mechanisms and explains the importance of different time scale.

Numerical and Experimental Investigation of a Micromix Combustor for a Hydrogen Fuelled µ-Scale Gas Turbine

2009 ◽  
Author(s):  
A. E. Robinson ◽  
H. H.-W. Funke ◽  
R. Wagemakers ◽  
J. Grossen ◽  
W. Bosschaerts ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Mass Flow ◽  
Gas Turbines ◽  
Ambient Pressure ◽  
High Energy ◽  
High Energy Density ◽  
Design Parameters ◽  
Small Scale ◽  
Symmetric Model ◽  
Cfd Model

This last decade has shown an increased interest in the downsizing of gas turbines to micro-scale. Their potential for high energy density makes them extremely attractive for small scale high power units as alternative to traditional unwieldy accumulators or as thrust systems in small robots and unmanned aerial vehicles (UAVs). Beneath great challenges with the rotating parts at this small scale, another crucial item is in fact the combustion chamber needed for a safe and reliable operation. This paper presents a study to an alternative approach in μ-scale hydrogen combustion. The burning principle is based upon the so-called inverse micromix injection. In this non-premixed design, hydrogen fuel is introduced through a porous metal and injected in the axial direction into the combustion chamber. A CFD-model has been implemented to parameterise the different geometrical aspects of the combustion chamber and is set up as a 2D axis-symmetric model to allow for a rapid optimisation of the parameters. The flow calculations are done with a commercial CFD-software. The final optimised geometry showed stable combustion, a well suited temperature profile and acceptable wall temperatures. An overview on the influence of the critical design parameters for the different geometries is presented. Experimental investigations comprise a set of mass flow variations coupled with a variation of the equivalence ratio for each mass flow but always at ambient pressure conditions. With the data obtained by an exhaust gas analysis, a full characterisation concerning combustion efficiency and stability of the burning principle is possible. Combined with the wall temperature measurements, these results lead to a further validation of the CFD model.

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