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Victoria Sanderson - One of the best experts on this subject based on the ideXlab platform.
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experimental and numerical investigation of fuel air mixing in a radial swirler slot of a Dry Low Emission gas turbine combustor
Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2014Co-Authors: Festus Agbonzikilo, I Owen, Jill Stewart, Suresh Sadasivuni, Mike Riley, Victoria SandersonAbstract:This paper presents the results of an investigation in which the fuel/air mixing process in a single slot within the radial swirler of a Dry Low Emission (DLE) combustion system is explored using air/air mixing. Experimental studies have been carried out on an atmospheric test facility in which the test domain is a large-scale representation of a swirler slot from a Siemens proprietary DLE combustion system. Hot air with a temperature of 300 °C is supplied to the slot, while the injected fuel gas is simulated using air jets with temperatures of about 25 °C. Temperature has been used as a scalar to measure the mixing of the jets with the cross-fLow. The mixture temperatures were measured using thermocouples while Pitot probes were used to obtain local velocity measurements. The experimental data have been used to validate a computational fluid dynamics (CFD) mixing model. Numerical simulations were carried out using CFD software ansys-cfx. Due to the complex three-dimensional fLow structure inside the swirler slot, different Reynolds-averaged Navier–Stokes (RANS) turbulence models were tested. The shear stress transport (SST) turbulence model was observed to give best agreement with the experimental data. The momentum flux ratio between the main air fLow and the injected fuel jet, and the aerodynamics inside the slot were both identified by this study as major factors in determining the mixing characteristics. It has been shown that mixing in the swirler can be significantly improved by exploiting the aerodynamic characteristics of the fLow inside the slot. The validated CFD model provides a tool which will be used in future studies to explore fuel/air mixing at engine conditions.
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Experimental and Numerical Investigation of Fuel-Air Mixing in a Radial Swirler Slot of a Dry Low Emission Gas Turbine Combustor
Volume 4B: Combustion Fuels and Emissions, 2014Co-Authors: Festus Agbonzikilo, I Owen, Jill Stewart, Suresh Sadasivuni, Mike Riley, Victoria SandersonAbstract:This paper presents the results of an investigation in which the fuel/air mixing process in a single slot within the radial swirler of a Dry Low Emission (DLE) combustion system is explored using air/air mixing. Experimental studies have been carried out on an atmospheric test facility in which the test domain is a large-scale representation of a swirler slot from a Siemens DLE SGT-400 combustion system. Hot air with a temperature of 300°C is supplied to the slot, while the injected fuel gas is represented using air jets with temperatures of about 25°C. Temperature has been used as a scalar to measure the mixing of the jets with the cross-fLow. The mixture temperatures were measured using thermocouples while Pitot probes were used to obtain local velocity measurements. The experimental data have been used to validate a computational fluid dynamics (CFD) mixing model. Numerical simulations were carried out using CFD software ANSYS-CFX. Due to the complex three-dimensional fLow structure inside the swirler slot, different RANS turbulence models were tested. The shear stress transport (SST) turbulence model was observed to give best agreement with the experimental data. The momentum flux ratio between the main air fLow and the injected fuel jet, and the aerodynamics inside the slot, were both identified by this study as major factors in determining the mixing characteristics. It has been shown that mixing in the swirler can be significantly improved by exploiting the aerodynamic characteristics of the fLow inside the slot. The validated CFD model provides a tool which will be used in future studies to explore fuel/air mixing at engine conditions.
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effect of change in fuel compositions and heating value on ignition and performance for siemens sgt 400 Dry Low Emission combustion system
Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2013Co-Authors: Pete Martin, Victoria Sanderson, Phill HubbardAbstract:The influence of changes in fuel composition and heating value on the performance of an industrial gas turbine combustor was investigated. The combustor tested was a single cannular combustor for Siemens SGT-400 13.4 MW Dry Low Emission (DLE) engine. Ignition, engine starting, Emissions, combustion dynamics and flash back through burner metal temperature monitoring were among the parameters investigated to evaluate the impact of fuel flexibility on combustor performance. Lean ignition and extinction limits were measured for three fuels with different heat values in term of Wobbe Index (WI): 25, 28.9 and 45 MJ/Sm 3 (natural gas). The test results show that the air fuel ratio (AFR) at lean ignition/extinction limits decreases and the margin between the two limits tends to be smaller as fuel heat value decreases. Engine start tests were also performed with a Lower heating value fuel and results were found to be comparable to those for engine starting with natural gas. The combustor was further tested in a high pressure air facility at real engine operating conditions with different fuels covering WIs from 17.5 to 70 MJ/Sm 3 . The variation in fuel composition and heating value was achieved in a gas mixing plant by blending natural gas with CO2, CO, N2 and H2 (for the fuel with WI Lower than natural gas) and C 3 H 8 (for the fuel with WI higher than natural gas). Test results show that a benefit in NOx reduction can be seen for the Lower WI fuels without H2 presence in the fuel and there are no adverse impacts on combustor performance except for the requirement of higher fuel supply pressure, however, this can be easily resolved by minor modification through the fuel injection design. Test results for the H2 enriched and higher WI fuels show that NOx, combustion dynamics and flash back have been adversely affected and major change in burner design is required. For the H2 enriched fuel, the effect of CO and H2 on combustor performance was also investigated for the fuels having a fixed WI of 29 MJ/Sm 3
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Effect of Change in Fuel Compositions and Heating Value on Ignition and Performance for Siemens SGT-400 Dry Low Emission Combustion System
Journal of Engineering for Gas Turbines and Power, 2013Co-Authors: Kexin Liu, Pete Martin, Victoria Sanderson, Phill HubbardAbstract:The influence of changes in fuel composition and heating value on the performance of an industrial gas turbine combustor was investigated. The combustor tested was a single cannular combustor for Siemens SGT-400 13.4 MW Dry Low Emission engine. Ignition, engine starting, Emissions, combustion dynamics, and flash back through burner metal temperature monitoring were among the parameters investigated to evaluate the impact of fuel flexibility on combustor performance. Lean ignition and extinction limits were measured for three fuels with different heat values in term of Wobbe Index (WI): 25, 28.9, and 45 MJ/Sm 3 (natural gas). The test results show that the air fuel ratio at lean ignition/ extinction limits decreases and the margin between the two limits tends to be smaller as fuel heat value decreases. Engine start tests were also performed with a Lower heating value fuel and results were found to be comparable to those for engine starting with natu-ral gas. The combustor was further tested in a high pressure air facility at real engine operating conditions with different fuels covering WIs from 17.5 to 70 MJ/Sm 3 . The varia-tion in fuel composition and heating value was achieved in a gas mixing plant by blend-ing natural gas with CO 2 , CO, N 2 , and H 2 (for the fuel with WI Lower than natural gas) and C 3 H 8 (for the fuel with WI higher than natural gas). Test results show that a benefit in NO x reduction can be seen for the Lower WI fuels without H 2 presence in the fuel and there are no adverse impacts on combustor performance except for the requirement of higher fuel supply pressure, however, this can be easily resolved by minor modification through the fuel injection design. Test results for the H 2 enriched and higher WI fuels show that NO x , combustion dynamics and flash back have been adversely affected and major change in burner design is required. For the H 2 enriched fuel, the effect of CO and H 2 on combustor performance was also investigated for the fuels having a fixed WI of 29 MJ/Sm 3 . It is found that H 2 dominates the adverse impact on combustor performance. The chemical kinetic study shows that H 2 has significant effect on flame speed change and CO has significant effect on flame temperature change. Although the tests were per-formed on the Siemens SGT-400 combustion system, the results provide general guidance for the challenge of industrial gas turbine burner design for fuel flexibility.
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The influence of changes in fuel calorific value to combustion performance for Siemens SGT-300 Dry Low Emission combustion system
Fuel, 2013Co-Authors: Kexin Liu, Victoria SandersonAbstract:The effect of changes in fuel calorific value on combustion was investigated on a single standard Siemens SGT-300 7.9 MW Dry Low Emission (DLE) combustor in a high pressure rig at actual engine operating conditions. The change in fuel calorific value was achieved by blending CO2and/or N2with Natural Gas. The Lowest fuel calorific value was tested at a Wobbe Index (WI) of 23 MJ/m3which was associated with 35% CO2(in volume) added to Natural Gas. The engine loads tested varied from 5% to full load. NOx and CO Emissions were measured in addition to the frequency and amplitudes of pressure fluctuations and various temperatures. The impact of pilot split (ratio of pilot fuel to total fuel mass fLow rate) and fuel composition on these was investigated. The results showed a noticeable benefit where the reduction in WI provided a reduction in NOx Emissions. The amplitude of the pressure fluctuations was not an issue being controlled, where necessary, by pilot split. The test results showed that WI of 25 MJ/m3appeared critical to combustion performance compared to Natural Gas. Review of the literature and calculation of the flame properties attempted to provide explanations for the trends observed during testing. © 2012 Elsevier Ltd. All rights reserved.
Kexin Liu - One of the best experts on this subject based on the ideXlab platform.
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Effect of Change in Fuel Compositions and Heating Value on Ignition and Performance for Siemens SGT-400 Dry Low Emission Combustion System
Journal of Engineering for Gas Turbines and Power, 2013Co-Authors: Kexin Liu, Pete Martin, Victoria Sanderson, Phill HubbardAbstract:The influence of changes in fuel composition and heating value on the performance of an industrial gas turbine combustor was investigated. The combustor tested was a single cannular combustor for Siemens SGT-400 13.4 MW Dry Low Emission engine. Ignition, engine starting, Emissions, combustion dynamics, and flash back through burner metal temperature monitoring were among the parameters investigated to evaluate the impact of fuel flexibility on combustor performance. Lean ignition and extinction limits were measured for three fuels with different heat values in term of Wobbe Index (WI): 25, 28.9, and 45 MJ/Sm 3 (natural gas). The test results show that the air fuel ratio at lean ignition/ extinction limits decreases and the margin between the two limits tends to be smaller as fuel heat value decreases. Engine start tests were also performed with a Lower heating value fuel and results were found to be comparable to those for engine starting with natu-ral gas. The combustor was further tested in a high pressure air facility at real engine operating conditions with different fuels covering WIs from 17.5 to 70 MJ/Sm 3 . The varia-tion in fuel composition and heating value was achieved in a gas mixing plant by blend-ing natural gas with CO 2 , CO, N 2 , and H 2 (for the fuel with WI Lower than natural gas) and C 3 H 8 (for the fuel with WI higher than natural gas). Test results show that a benefit in NO x reduction can be seen for the Lower WI fuels without H 2 presence in the fuel and there are no adverse impacts on combustor performance except for the requirement of higher fuel supply pressure, however, this can be easily resolved by minor modification through the fuel injection design. Test results for the H 2 enriched and higher WI fuels show that NO x , combustion dynamics and flash back have been adversely affected and major change in burner design is required. For the H 2 enriched fuel, the effect of CO and H 2 on combustor performance was also investigated for the fuels having a fixed WI of 29 MJ/Sm 3 . It is found that H 2 dominates the adverse impact on combustor performance. The chemical kinetic study shows that H 2 has significant effect on flame speed change and CO has significant effect on flame temperature change. Although the tests were per-formed on the Siemens SGT-400 combustion system, the results provide general guidance for the challenge of industrial gas turbine burner design for fuel flexibility.
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The influence of changes in fuel calorific value to combustion performance for Siemens SGT-300 Dry Low Emission combustion system
Fuel, 2013Co-Authors: Kexin Liu, Victoria SandersonAbstract:The effect of changes in fuel calorific value on combustion was investigated on a single standard Siemens SGT-300 7.9 MW Dry Low Emission (DLE) combustor in a high pressure rig at actual engine operating conditions. The change in fuel calorific value was achieved by blending CO2and/or N2with Natural Gas. The Lowest fuel calorific value was tested at a Wobbe Index (WI) of 23 MJ/m3which was associated with 35% CO2(in volume) added to Natural Gas. The engine loads tested varied from 5% to full load. NOx and CO Emissions were measured in addition to the frequency and amplitudes of pressure fluctuations and various temperatures. The impact of pilot split (ratio of pilot fuel to total fuel mass fLow rate) and fuel composition on these was investigated. The results showed a noticeable benefit where the reduction in WI provided a reduction in NOx Emissions. The amplitude of the pressure fluctuations was not an issue being controlled, where necessary, by pilot split. The test results showed that WI of 25 MJ/m3appeared critical to combustion performance compared to Natural Gas. Review of the literature and calculation of the flame properties attempted to provide explanations for the trends observed during testing. © 2012 Elsevier Ltd. All rights reserved.
Phill Hubbard - One of the best experts on this subject based on the ideXlab platform.
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Reduction of Burner Variants for Differing Fuel Compositions by Combining Intelligent Control Methods and Experimental Data of Siemens SGT-400 Dry Low Emission Combustion System
Volume 4B: Combustion Fuels and Emissions, 2018Co-Authors: Phill Hubbard, Suresh Sadasivuni, Ghenadie BulatAbstract:Extension of gas fuel flexibility of a current production standard SGT-400 industrial gas turbine combustor is reported in this paper. A successful development program has increased the capability of the standard production Dry Low Emissions burner configuration to burn a range of fuels covering a temperature corrected wobbe index from 30 to 49 MJ/m3. A standard SGT-400 13.4 MW Dry Low Emission double skinned combustor can was tested with a standard production gas burner for a cannular combustion system. Emissions, combustion dynamics, fuel pressure and flashback monitoring via measurement of burner metal temperatures, were the main parameters used to evaluate the impact of fuel flexibility on combustor performance. High pressure rig tests were carried out to demonstrate the capabilities of the combustion system at engine operating conditions across a wide range of ambient conditions. Variations of the fuel heating value were achieved by blending natural gas with CO2 as diluent. The standard SGT-400 combustion system employs proven Dry Low Emissions technology for natural gas and liquid fuels such as diesel within a specified range of fuel heating values. With the aid of novel intelligent control software, the gas fuel capability of the SGT-400 standard Dry Low Emissions burner has been extended, with the engine, achieving stable operation and reduced Emissions across the load range despite variations of the composition of the fuel supply. This, combined with previous experience from high pressure rig and engine testing of the different burner configurations that covered this range, resulted in a reduction in the number of hardware configurations from three burners to two. Testing showed that the standard production burner can reliably operate with a fuel temperature controlled wobbe index as Low as 30 MJ/m3 which corresponds to 20% CO2 (by volume) in the fuel. The performance of four different fuels with heating values in terms of temperature controlled wobbe index: 30, 33, 35 and 45 MJ/m3 (natural gas), is presented for the current production hardware. Test results show that NOx Emissions decrease as the fuel heating value is reduced. Also note that a decreasing temperature controlled wobbe index leads to a requirement to increase the fuel supply pressure. The tests results obtained on the Siemens SGT-400 combustion system provide significant improvement for industrial gas turbine burner design for fuel flexibility.
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effect of change in fuel compositions and heating value on ignition and performance for siemens sgt 400 Dry Low Emission combustion system
Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2013Co-Authors: Pete Martin, Victoria Sanderson, Phill HubbardAbstract:The influence of changes in fuel composition and heating value on the performance of an industrial gas turbine combustor was investigated. The combustor tested was a single cannular combustor for Siemens SGT-400 13.4 MW Dry Low Emission (DLE) engine. Ignition, engine starting, Emissions, combustion dynamics and flash back through burner metal temperature monitoring were among the parameters investigated to evaluate the impact of fuel flexibility on combustor performance. Lean ignition and extinction limits were measured for three fuels with different heat values in term of Wobbe Index (WI): 25, 28.9 and 45 MJ/Sm 3 (natural gas). The test results show that the air fuel ratio (AFR) at lean ignition/extinction limits decreases and the margin between the two limits tends to be smaller as fuel heat value decreases. Engine start tests were also performed with a Lower heating value fuel and results were found to be comparable to those for engine starting with natural gas. The combustor was further tested in a high pressure air facility at real engine operating conditions with different fuels covering WIs from 17.5 to 70 MJ/Sm 3 . The variation in fuel composition and heating value was achieved in a gas mixing plant by blending natural gas with CO2, CO, N2 and H2 (for the fuel with WI Lower than natural gas) and C 3 H 8 (for the fuel with WI higher than natural gas). Test results show that a benefit in NOx reduction can be seen for the Lower WI fuels without H2 presence in the fuel and there are no adverse impacts on combustor performance except for the requirement of higher fuel supply pressure, however, this can be easily resolved by minor modification through the fuel injection design. Test results for the H2 enriched and higher WI fuels show that NOx, combustion dynamics and flash back have been adversely affected and major change in burner design is required. For the H2 enriched fuel, the effect of CO and H2 on combustor performance was also investigated for the fuels having a fixed WI of 29 MJ/Sm 3
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Effect of Change in Fuel Compositions and Heating Value on Ignition and Performance for Siemens SGT-400 Dry Low Emission Combustion System
Journal of Engineering for Gas Turbines and Power, 2013Co-Authors: Kexin Liu, Pete Martin, Victoria Sanderson, Phill HubbardAbstract:The influence of changes in fuel composition and heating value on the performance of an industrial gas turbine combustor was investigated. The combustor tested was a single cannular combustor for Siemens SGT-400 13.4 MW Dry Low Emission engine. Ignition, engine starting, Emissions, combustion dynamics, and flash back through burner metal temperature monitoring were among the parameters investigated to evaluate the impact of fuel flexibility on combustor performance. Lean ignition and extinction limits were measured for three fuels with different heat values in term of Wobbe Index (WI): 25, 28.9, and 45 MJ/Sm 3 (natural gas). The test results show that the air fuel ratio at lean ignition/ extinction limits decreases and the margin between the two limits tends to be smaller as fuel heat value decreases. Engine start tests were also performed with a Lower heating value fuel and results were found to be comparable to those for engine starting with natu-ral gas. The combustor was further tested in a high pressure air facility at real engine operating conditions with different fuels covering WIs from 17.5 to 70 MJ/Sm 3 . The varia-tion in fuel composition and heating value was achieved in a gas mixing plant by blend-ing natural gas with CO 2 , CO, N 2 , and H 2 (for the fuel with WI Lower than natural gas) and C 3 H 8 (for the fuel with WI higher than natural gas). Test results show that a benefit in NO x reduction can be seen for the Lower WI fuels without H 2 presence in the fuel and there are no adverse impacts on combustor performance except for the requirement of higher fuel supply pressure, however, this can be easily resolved by minor modification through the fuel injection design. Test results for the H 2 enriched and higher WI fuels show that NO x , combustion dynamics and flash back have been adversely affected and major change in burner design is required. For the H 2 enriched fuel, the effect of CO and H 2 on combustor performance was also investigated for the fuels having a fixed WI of 29 MJ/Sm 3 . It is found that H 2 dominates the adverse impact on combustor performance. The chemical kinetic study shows that H 2 has significant effect on flame speed change and CO has significant effect on flame temperature change. Although the tests were per-formed on the Siemens SGT-400 combustion system, the results provide general guidance for the challenge of industrial gas turbine burner design for fuel flexibility.
Ghenadie Bulat - One of the best experts on this subject based on the ideXlab platform.
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Extension of Fuel Flexibility by Combining Intelligent Control Methods for Siemens SGT-400 Dry Low Emission Combustion System
Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2018Co-Authors: K Liu Kexin, Suresh Sadasivuni, Phillip Hubbard, Ghenadie BulatAbstract:Extension of gas fuel flexibility of a current production SGT-400 industrial gas turbine combustor system is reported in this paper. A SGT-400 engine with hybrid combustion system configuration to meet a customer's specific requirements was string tested. This engine was tested with the gas turbine package driver unit and the gas compressor-driven unit to operate on and switch between three different fuels with temperature-corrected Wobbe index (TCWI) varying between 45 MJ/m3, 38 MJ/m3, and 30 MJ/m3. The alteration of fuel heating value was achieved by injection or withdrawal of N2 into or from the fuel system. The results show that the engine can maintain stable operation on and switching between these three different fuels with fast changeover rate of the heating value greater than 10% per minute without shutdown or change in load condition. High-pressure rig tests were carried out to demonstrate the capabilities of the combustion system at engine operating conditions across a wide range of ambient conditions. Variations of the fuel heating value, with Wobbe index (WI) of 30 MJ/Sm3, 33 MJ/Sm3, 35 MJ/Sm3, and 45 MJ/Sm3 (natural gas, NG) at standard conditions, were achieved by blending NG with CO2 as diluent. Emissions, combustion dynamics, fuel pressure, and flashback monitoring via measurement of burner metal temperatures, were the main parameters used to evaluate the impact of fuel flexibility on combustor performance. Test results show that NOx Emissions decrease as the fuel heating value is reduced. Also note that a decreasing fuel heating value leads to a requirement to increase the fuel supply pressure. Effect of fuel heating value on combustion was investigated, and the reduction in adiabatic flame temperature and laminar flame speed was observed for Lower heating value fuels. The successful development program has increased the capability of the SGT-400 standard production Dry Low Emissions (DLE) burner configuration to operate with a range of fuels covering a WI corrected to the normal conditions from 30 MJ/N·m3 to 49 MJ/N·m3. The tests results obtained on the Siemens SGT-400 combustion system provide significant experience for industrial gas turbine burner design for fuel flexibility.
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Reduction of Burner Variants for Differing Fuel Compositions by Combining Intelligent Control Methods and Experimental Data of Siemens SGT-400 Dry Low Emission Combustion System
Volume 4B: Combustion Fuels and Emissions, 2018Co-Authors: Phill Hubbard, Suresh Sadasivuni, Ghenadie BulatAbstract:Extension of gas fuel flexibility of a current production standard SGT-400 industrial gas turbine combustor is reported in this paper. A successful development program has increased the capability of the standard production Dry Low Emissions burner configuration to burn a range of fuels covering a temperature corrected wobbe index from 30 to 49 MJ/m3. A standard SGT-400 13.4 MW Dry Low Emission double skinned combustor can was tested with a standard production gas burner for a cannular combustion system. Emissions, combustion dynamics, fuel pressure and flashback monitoring via measurement of burner metal temperatures, were the main parameters used to evaluate the impact of fuel flexibility on combustor performance. High pressure rig tests were carried out to demonstrate the capabilities of the combustion system at engine operating conditions across a wide range of ambient conditions. Variations of the fuel heating value were achieved by blending natural gas with CO2 as diluent. The standard SGT-400 combustion system employs proven Dry Low Emissions technology for natural gas and liquid fuels such as diesel within a specified range of fuel heating values. With the aid of novel intelligent control software, the gas fuel capability of the SGT-400 standard Dry Low Emissions burner has been extended, with the engine, achieving stable operation and reduced Emissions across the load range despite variations of the composition of the fuel supply. This, combined with previous experience from high pressure rig and engine testing of the different burner configurations that covered this range, resulted in a reduction in the number of hardware configurations from three burners to two. Testing showed that the standard production burner can reliably operate with a fuel temperature controlled wobbe index as Low as 30 MJ/m3 which corresponds to 20% CO2 (by volume) in the fuel. The performance of four different fuels with heating values in terms of temperature controlled wobbe index: 30, 33, 35 and 45 MJ/m3 (natural gas), is presented for the current production hardware. Test results show that NOx Emissions decrease as the fuel heating value is reduced. Also note that a decreasing temperature controlled wobbe index leads to a requirement to increase the fuel supply pressure. The tests results obtained on the Siemens SGT-400 combustion system provide significant improvement for industrial gas turbine burner design for fuel flexibility.
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Investigation of an Industrial Gas Turbine Combustor and Pollutant Formation Using LES
Volume 4B: Combustion Fuels and Emissions, 2017Co-Authors: George Mallouppas, Graham Goldin, Yongzhe Zhang, Piyush Thakre, Niveditha Krishnamoorthy, Rajesh Rawat, David Gosman, Jim Rogerson, Ghenadie BulatAbstract:An experimental variant of a commercial swirl burner for industrial gas turbine combustors operating at 3 bar is numerically investigated using high-fidelity Computational Fluid Dynamics models using STAR-CCM+ v11.06. This work presents the computational results of the SGT-100 Dry Low Emission gas turbine provided by Siemens Industrial Turbomachinery Ltd. The related experimental study was performed at the DLR Institute of Combustion Technology, Stuttgart, Germany. The objective of this work is to compare the performance of the Flamelet Generated Manifold model, which is the widely accepted combustion model in Gas Turbines with the Complex Chemistry model. In particular this work examines the flame shape and position, pollutant formation predicted by the aforementioned models with Large Eddy Simulations. Mean and RMS quantities of the fLow field, flame temperatures and major species are presented and compared with the experiments. The results show that the predictions are insensitive on the meshing strategy and at the evaluated mesh sizes of ∼10 million and ∼44 million cells. The mean and RMS errors are ∼8% compared to the reported experiments and these differences are within the measurement errors. The results show that the calculated flame positions are in very good agreement with the reported measurements and the typical M-shape flame is reproduced independent of the combustion model. Pollutant formation in the combustor predicted by two combustion models is scrutinised. The predicted NO and CO Emissions levels are in agreement with the literature.
A.a. Subash - One of the best experts on this subject based on the ideXlab platform.
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experimental investigation of the influence of burner geometry on flame characteristics at a Dry Low Emission industrial prototype burner at atmospheric pressure conditions
ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition GT 2017, 2017Co-Authors: A.a. Subash, Marcus Aldén, Robert Collin, Atanu Kundu, Jens KlingmannAbstract:Laser based investigations were performed on a prototype 4th generation DLE (Dry Low Emission) burner under atmospheric pressure conditions to study the effects of changing burner geometry on the flame. In a full burner configuration, a divergent conical section termed the Quarl is located after the burner exit for expanding the fLow area and holding the flame. The planar laser-induced fluorescence (PLIF) of OH radicals together with the flame chemiluminescence imaging were employed to study the flame characteristics under the conditions with and without Quarl using CH4 as fuel to understand the influence of Quarl on the flame. When there is no Quarl, the flame has more freedom to expand at the burner exit and with an increase in the global equivalence ratio (φ), the width of the flame increases and the total extension of the flame shortens. For all the global φ considered here, the total extension of the flame is shorter under the condition without Quarl in comparison to the one with Quarl. For a richer global φ(φ≥ 0.46) the outer recirculation zones (ORZs) are not observed under the condition with Quarl, but are observed without Quarl along with the inner recirculation zone. Without Quarl conditions, equivalence ratios (φ) of the concentrically arranged three sections of the burner: an outer Main section, an intermediate section (Pilot) and a central pilot body or pre-chamber combustor, termed the RPL (Rich-Pilot-Lean) sections were altered. The results show that at a constant global φ, with an increase in the RPL φ and the Pilot φ, the flame shortens and expands radially as well as the flame stabilization zone that is produced after the burner exit moves further downstream. At a richer global φ, the ORZ is observed along with the inner recirculation zone of the flame. Otherwise, with an increase in global φ, the changes in the flame shape, in the flame fluctuation and in the flame stabilization position folLow similar trends as for increasing the Pilot φ and the RPL φ Additionally, combustion Emissions were obtained to observe the effects on NOX level for different operating conditions with and without Quarl. (Less)
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investigation of hydrogen enriched methane flame in a Dry Low Emission industrial prototype burner at atmospheric pressure conditions
ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition GT 2017, 2017Co-Authors: A.a. Subash, Marcus Aldén, Robert Collin, Atanu Kundu, Jens KlingmannAbstract:Experiments were performed on a prototype 4th generation DLE (Dry Low Emission) burner under atmospheric pressure conditions to investigate the effects of hydrogen (H2) enrichment on methane (CH4) flames. The burner assembly was designed to have three concentrically arranged premixed sections: an outer Main section, an intermediate section (Pilot) and a central pilot body termed the RPL (Rich-Pilot-Lean) section. The Planar laser-induced fluorescence (PLIF) of OH radicals together with flame chemiluminescence imaging were employed for studying the local flame characteristics so as to be able to investigate the turbulence-flame interactions and the location of the reaction zone at the burner exit. Flames were investigated for three different fuel mixtures having hydrogen (H2)/methane (CH4) in vol. % concentration of 0/100, 25/75 and 50/50. The results show that the characteristics of the flames are clearly affected by the addition of hydrogen and the effects are expected due to the faster reaction rate, higher diffusivity and higher laminar burning velocity of H2. Enriching the flame with H2 at a constant global phi (φ) is found to shorten the total extension of the flame due to the higher laminar flame speed. The OH signal distribution becomes thicker and more pronounced due to the higher production of OH radicals, and the flame stabilization zone that is produced after the burner throat, moves further downstream. At a constant global φ in altering the RPL and the Pilot φ, similar changes for both 0/100 and 25/75 (in vol. %) of the H2/CH4 fuel mixtures can be observed. At a rich RPL φ, the secondary RPL flame contributes to the main flame and to determining the flame stabilization position. The flame stabilization zone located after the burner throat moves further downstream with an increase in the RPL φ. When the PFR (Pilot fuel ratio) increases, the extension of the flame shortens and the flame stabilization zone moves upstream. Combustion Emissions were also determined so as to observe the effects of the H2 enrichment on the NOX level. (Less)
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laser based investigation on a Dry Low Emission industrial prototype burner at atmospheric pressure conditions
ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition GT 2016, 2016Co-Authors: A.a. Subash, Marcus Aldén, Robert Collin, Atanu Kundu, Jens KlingmannAbstract:Experiments were performed at atmospheric pressure conditions on the prototype 4th generation DLE burner. The combustion changes that occur for alteration of the operating conditions by changing the equivalence ratios (φ) for CH4 as fuel at different sections of the burner, were optically investigated. The burner assembly has three concentrically arranged premixed burner sections: an outer Main section, an intermediate section (Pilot) and a central pilot body or pre-chamber combustor, called RPL (Rich-Pilot-Lean) section. All sections are facilitated to vary equivalence ratios to achieve optimal combustion. Planar laser-induced fluorescence (PLIF) of OH radicals and flame chemiluminescence imaging were applied to study the local flame characteristics in order to investigate turbulence-flame interaction and formation of reaction zone at the burner exit. The results show that the position and shape of the flame are clearly affected by the variation of equivalence ratios at different sections of the burner. During the experiments, first the RPL, then the Pilot and the Main flame were added in a step wise manner keeping constant the total air fLow for the global φ= 0.5 in order to understand the flame contributions from the different combustion sections. It is observed that for the RPL fuel lean conditions, the primary combustion starts and reaches completion before exiting the burner throat while for rich conditions, the residual fuel escapes out through the RPL exit with primary combustion products and starts secondary combustion along with the Pilot and Main combustion. At the global φ= 0.5, for changing the RPL φ from lean to rich conditions, the flame stabilization region moves downstream of the burner exit and the flame front fluctuation along inner shear layer increases. For increasing the global φ and increasing the Pilot fuel ratio (PFR) without changing the RPL and the global φ, the total extension of the flame becomes shorter and the flame stabilization region moves upstream. (Less)
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Pilot-pilot interaction effects on a prototype DLE gas turbine burner combustion
Volume 4B: Combustion Fuels and Emissions, 2016Co-Authors: Atanu Kundu, A.a. Subash, Jens Klingmann, Robert CollinAbstract:Lean premixed Dry Low Emission (DLE) combustion system in a gas turbine engine is a globally accepted concept to reduce pollutant Emissions and to improve combustion efficiency. This study is focused on an industrial downscaled prototype burner (4th Generation Dry Low Emission Burner for SGT-750 designed and manufactured by Siemens Industrial Turbo machinery AB), which has been tested extensively at atmospheric conditions. To enhance the operability and alleviate flame dynamics behavior, multiple fuel and air circuits (i.e. Rich-Pilot-Lean (RPL), Pilot and Main) are engaged in the burner. Primarily, present study evaluates the RPL-Pilot interaction effect on the main combustion zone. A highly swirled fLow from the burner exit produces a central recirculation zones (CRZ) to recirculate the hot vitiated gas for sustaining the combustion process. The main flame is stabilized in the inner shear layer (ISL), which is found in the diverging section (named as Quarl). The total power of the burner was varied between 70-140 kW and the fuel used for the experiment was 99.5% pure methane. A short length quartz liner was used for the experiment and the residence time of the combustor is 9 ms. At the liner exit, Emission sampling (CO, NOx) has been conducted using a water-cooled Emission probe. Optical measurements were permitted, as the Quarl and combustor liner were optically accessible. Planar laser-induced fluorescence of OH molecule (OH-PLIF) and natural chemiluminescence measurements were conducted to visualize the flame characteristics and its response by changing the RPL and Pilot fuel splits. A comprehensive study was performed by varying the RPL residence time to investigate the main flame stabilization and pollutant formation of the burner. Higher RPL residence time exhibits NOx benefits but at the same time flame instability was increased. Pilot fuel percentage modification demonstrate negative impact on NOx formation due to the limited mixing of fuel and air. With the increase of Pilot fuel split, CO Emission decreases, which is advantageous for increasing the LBO margin. The study has identified a number of critical situations where the flame was stabilized without any RPL and Pilot combustion. Apart from the experimental results, a simple reactor network model has been applied for predicting NOx Emission. Different kinetic mechanisms were assessed and the prediction results are compared to experimental results. Heat loss from the combustor wall played a significant role on Emission formation and was included in the reactor model. This study provides a good understanding of the new DLE industrial burner concept and the RPL-pilot interaction effect on the Emission. (Less)
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Investigation of ozone stimulated combustion in the SGT-800 burner at atmospheric conditions
Proceedings of the ASME Turbo Expo, 2016Co-Authors: Annika Lantz, A.a. Subash, E.j.k. Nilsson, Junqiang Zhu, Andreas Ehn, Jenny Larfeldt, Zili Li, Marcus AldénAbstract:Copyright © 2016 by ASME. The effect of ozone (O 3 ) in a turbulent, swirl-stabilized natural gas/air flame was experimentally investigated at atmospheric pressure conditions using planar laser-induced fluorescence imaging of formaldehyde (CH 2 O PLIF) and dynamic pressure monitoring. The experiment was performed using a Dry Low Emission (DLE) gas turbine burner used in both SGT-700 and SGT-800 industrial gas turbines from Siemens. The burner was mounted in an atmospheric combustion test rig at Siemens with optical access in the flame region. CH 2 O PLIF imaging was carried out for four different seeding gas compositions and seeding injection channel configurations. Two seeding injection-channels were located around the burner tip while the other two were located along the center axis of the burner at different distances upstream the burner outlet. Four different seeding gas compositions were used: nitrogen (N 2 ), oxygen (O 2 ) and two ozone/oxygen (O 3 /O 2 ) mixtures with different O 3 concentration. The results show that the O 3 clearly affects the combustion chemistry. The natural gas/air mixture is preheated before combustion which is shown to kick-start the cold combustion chemistry where O 3 is highly involved. The CH 2 O PLIF signal increases with O 3 seeded into the flame which indicates that the pre-combustion activity increases and that the cold chemistry starts to develop further upstream. The small increase of the pressure drop over the burner shows that the flame moves upstream when O 3 is seeded into the flame, which confirms the increase in pre-combustion activity.
